From 904e315dae7a937465b762a0c0e8ccb4ccd27dc0 Mon Sep 17 00:00:00 2001 From: John Ericson Date: Sun, 11 Oct 2020 16:26:54 +0000 Subject: Rename to hand-hold git (build/worker.cc) --- src/libstore/build.cc | 5654 ------------------------------------------ src/libstore/build/worker.cc | 5654 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 5654 insertions(+), 5654 deletions(-) delete mode 100644 src/libstore/build.cc create mode 100644 src/libstore/build/worker.cc (limited to 'src/libstore') diff --git a/src/libstore/build.cc b/src/libstore/build.cc deleted file mode 100644 index 5757e5c3f..000000000 --- a/src/libstore/build.cc +++ /dev/null @@ -1,5654 +0,0 @@ -#include "references.hh" -#include "pathlocks.hh" -#include "globals.hh" -#include "local-store.hh" -#include "util.hh" -#include "archive.hh" -#include "affinity.hh" -#include "builtins.hh" -#include "builtins/buildenv.hh" -#include "filetransfer.hh" -#include "finally.hh" -#include "compression.hh" -#include "json.hh" -#include "nar-info.hh" -#include "parsed-derivations.hh" -#include "machines.hh" -#include "daemon.hh" -#include "worker-protocol.hh" -#include "topo-sort.hh" -#include "callback.hh" - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include - -/* Includes required for chroot support. */ -#if __linux__ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#if HAVE_SECCOMP -#include -#endif -#define pivot_root(new_root, put_old) (syscall(SYS_pivot_root, new_root, put_old)) -#endif - -#if HAVE_STATVFS -#include -#endif - -#include - - -namespace nix { - -using std::map; - - -static string pathNullDevice = "/dev/null"; - - -/* Forward definition. */ -class Worker; -struct HookInstance; - - -/* A pointer to a goal. */ -struct Goal; -class DerivationGoal; -typedef std::shared_ptr GoalPtr; -typedef std::weak_ptr WeakGoalPtr; - -struct CompareGoalPtrs { - bool operator() (const GoalPtr & a, const GoalPtr & b) const; -}; - -/* Set of goals. */ -typedef set Goals; -typedef list WeakGoals; - -/* A map of paths to goals (and the other way around). */ -typedef std::map WeakGoalMap; - - - -struct Goal : public std::enable_shared_from_this -{ - typedef enum {ecBusy, ecSuccess, ecFailed, ecNoSubstituters, ecIncompleteClosure} ExitCode; - - /* Backlink to the worker. */ - Worker & worker; - - /* Goals that this goal is waiting for. */ - Goals waitees; - - /* Goals waiting for this one to finish. Must use weak pointers - here to prevent cycles. */ - WeakGoals waiters; - - /* Number of goals we are/were waiting for that have failed. */ - unsigned int nrFailed; - - /* Number of substitution goals we are/were waiting for that - failed because there are no substituters. */ - unsigned int nrNoSubstituters; - - /* Number of substitution goals we are/were waiting for that - failed because othey had unsubstitutable references. */ - unsigned int nrIncompleteClosure; - - /* Name of this goal for debugging purposes. */ - string name; - - /* Whether the goal is finished. */ - ExitCode exitCode; - - /* Exception containing an error message, if any. */ - std::optional ex; - - Goal(Worker & worker) : worker(worker) - { - nrFailed = nrNoSubstituters = nrIncompleteClosure = 0; - exitCode = ecBusy; - } - - virtual ~Goal() - { - trace("goal destroyed"); - } - - virtual void work() = 0; - - void addWaitee(GoalPtr waitee); - - virtual void waiteeDone(GoalPtr waitee, ExitCode result); - - virtual void handleChildOutput(int fd, const string & data) - { - abort(); - } - - virtual void handleEOF(int fd) - { - abort(); - } - - void trace(const FormatOrString & fs); - - string getName() - { - return name; - } - - /* Callback in case of a timeout. It should wake up its waiters, - get rid of any running child processes that are being monitored - by the worker (important!), etc. */ - virtual void timedOut(Error && ex) = 0; - - virtual string key() = 0; - - void amDone(ExitCode result, std::optional ex = {}); -}; - - -bool CompareGoalPtrs::operator() (const GoalPtr & a, const GoalPtr & b) const { - string s1 = a->key(); - string s2 = b->key(); - return s1 < s2; -} - - -typedef std::chrono::time_point steady_time_point; - - -/* A mapping used to remember for each child process to what goal it - belongs, and file descriptors for receiving log data and output - path creation commands. */ -struct Child -{ - WeakGoalPtr goal; - Goal * goal2; // ugly hackery - set fds; - bool respectTimeouts; - bool inBuildSlot; - steady_time_point lastOutput; /* time we last got output on stdout/stderr */ - steady_time_point timeStarted; -}; - - -/* The worker class. */ -class Worker -{ -private: - - /* Note: the worker should only have strong pointers to the - top-level goals. */ - - /* The top-level goals of the worker. */ - Goals topGoals; - - /* Goals that are ready to do some work. */ - WeakGoals awake; - - /* Goals waiting for a build slot. */ - WeakGoals wantingToBuild; - - /* Child processes currently running. */ - std::list children; - - /* Number of build slots occupied. This includes local builds and - substitutions but not remote builds via the build hook. */ - unsigned int nrLocalBuilds; - - /* Maps used to prevent multiple instantiations of a goal for the - same derivation / path. */ - WeakGoalMap derivationGoals; - WeakGoalMap substitutionGoals; - - /* Goals waiting for busy paths to be unlocked. */ - WeakGoals waitingForAnyGoal; - - /* Goals sleeping for a few seconds (polling a lock). */ - WeakGoals waitingForAWhile; - - /* Last time the goals in `waitingForAWhile' where woken up. */ - steady_time_point lastWokenUp; - - /* Cache for pathContentsGood(). */ - std::map pathContentsGoodCache; - -public: - - const Activity act; - const Activity actDerivations; - const Activity actSubstitutions; - - /* Set if at least one derivation had a BuildError (i.e. permanent - failure). */ - bool permanentFailure; - - /* Set if at least one derivation had a timeout. */ - bool timedOut; - - /* Set if at least one derivation fails with a hash mismatch. */ - bool hashMismatch; - - /* Set if at least one derivation is not deterministic in check mode. */ - bool checkMismatch; - - LocalStore & store; - - std::unique_ptr hook; - - uint64_t expectedBuilds = 0; - uint64_t doneBuilds = 0; - uint64_t failedBuilds = 0; - uint64_t runningBuilds = 0; - - uint64_t expectedSubstitutions = 0; - uint64_t doneSubstitutions = 0; - uint64_t failedSubstitutions = 0; - uint64_t runningSubstitutions = 0; - uint64_t expectedDownloadSize = 0; - uint64_t doneDownloadSize = 0; - uint64_t expectedNarSize = 0; - uint64_t doneNarSize = 0; - - /* Whether to ask the build hook if it can build a derivation. If - it answers with "decline-permanently", we don't try again. */ - bool tryBuildHook = true; - - Worker(LocalStore & store); - ~Worker(); - - /* Make a goal (with caching). */ - - /* derivation goal */ -private: - std::shared_ptr makeDerivationGoalCommon( - const StorePath & drvPath, const StringSet & wantedOutputs, - std::function()> mkDrvGoal); -public: - std::shared_ptr makeDerivationGoal( - const StorePath & drvPath, - const StringSet & wantedOutputs, BuildMode buildMode = bmNormal); - std::shared_ptr makeBasicDerivationGoal( - const StorePath & drvPath, const BasicDerivation & drv, - const StringSet & wantedOutputs, BuildMode buildMode = bmNormal); - - /* substitution goal */ - GoalPtr makeSubstitutionGoal(const StorePath & storePath, RepairFlag repair = NoRepair, std::optional ca = std::nullopt); - - /* Remove a dead goal. */ - void removeGoal(GoalPtr goal); - - /* Wake up a goal (i.e., there is something for it to do). */ - void wakeUp(GoalPtr goal); - - /* Return the number of local build and substitution processes - currently running (but not remote builds via the build - hook). */ - unsigned int getNrLocalBuilds(); - - /* Registers a running child process. `inBuildSlot' means that - the process counts towards the jobs limit. */ - void childStarted(GoalPtr goal, const set & fds, - bool inBuildSlot, bool respectTimeouts); - - /* Unregisters a running child process. `wakeSleepers' should be - false if there is no sense in waking up goals that are sleeping - because they can't run yet (e.g., there is no free build slot, - or the hook would still say `postpone'). */ - void childTerminated(Goal * goal, bool wakeSleepers = true); - - /* Put `goal' to sleep until a build slot becomes available (which - might be right away). */ - void waitForBuildSlot(GoalPtr goal); - - /* Wait for any goal to finish. Pretty indiscriminate way to - wait for some resource that some other goal is holding. */ - void waitForAnyGoal(GoalPtr goal); - - /* Wait for a few seconds and then retry this goal. Used when - waiting for a lock held by another process. This kind of - polling is inefficient, but POSIX doesn't really provide a way - to wait for multiple locks in the main select() loop. */ - void waitForAWhile(GoalPtr goal); - - /* Loop until the specified top-level goals have finished. */ - void run(const Goals & topGoals); - - /* Wait for input to become available. */ - void waitForInput(); - - unsigned int exitStatus(); - - /* Check whether the given valid path exists and has the right - contents. */ - bool pathContentsGood(const StorePath & path); - - void markContentsGood(const StorePath & path); - - void updateProgress() - { - actDerivations.progress(doneBuilds, expectedBuilds + doneBuilds, runningBuilds, failedBuilds); - actSubstitutions.progress(doneSubstitutions, expectedSubstitutions + doneSubstitutions, runningSubstitutions, failedSubstitutions); - act.setExpected(actFileTransfer, expectedDownloadSize + doneDownloadSize); - act.setExpected(actCopyPath, expectedNarSize + doneNarSize); - } -}; - - -////////////////////////////////////////////////////////////////////// - - -void addToWeakGoals(WeakGoals & goals, GoalPtr p) -{ - // FIXME: necessary? - // FIXME: O(n) - for (auto & i : goals) - if (i.lock() == p) return; - goals.push_back(p); -} - - -void Goal::addWaitee(GoalPtr waitee) -{ - waitees.insert(waitee); - addToWeakGoals(waitee->waiters, shared_from_this()); -} - - -void Goal::waiteeDone(GoalPtr waitee, ExitCode result) -{ - assert(waitees.find(waitee) != waitees.end()); - waitees.erase(waitee); - - trace(fmt("waitee '%s' done; %d left", waitee->name, waitees.size())); - - if (result == ecFailed || result == ecNoSubstituters || result == ecIncompleteClosure) ++nrFailed; - - if (result == ecNoSubstituters) ++nrNoSubstituters; - - if (result == ecIncompleteClosure) ++nrIncompleteClosure; - - if (waitees.empty() || (result == ecFailed && !settings.keepGoing)) { - - /* If we failed and keepGoing is not set, we remove all - remaining waitees. */ - for (auto & goal : waitees) { - WeakGoals waiters2; - for (auto & j : goal->waiters) - if (j.lock() != shared_from_this()) waiters2.push_back(j); - goal->waiters = waiters2; - } - waitees.clear(); - - worker.wakeUp(shared_from_this()); - } -} - - -void Goal::amDone(ExitCode result, std::optional ex) -{ - trace("done"); - assert(exitCode == ecBusy); - assert(result == ecSuccess || result == ecFailed || result == ecNoSubstituters || result == ecIncompleteClosure); - exitCode = result; - - if (ex) { - if (!waiters.empty()) - logError(ex->info()); - else - this->ex = std::move(*ex); - } - - for (auto & i : waiters) { - GoalPtr goal = i.lock(); - if (goal) goal->waiteeDone(shared_from_this(), result); - } - waiters.clear(); - worker.removeGoal(shared_from_this()); -} - - -void Goal::trace(const FormatOrString & fs) -{ - debug("%1%: %2%", name, fs.s); -} - - - -////////////////////////////////////////////////////////////////////// - - -void handleDiffHook( - uid_t uid, uid_t gid, - const Path & tryA, const Path & tryB, - const Path & drvPath, const Path & tmpDir) -{ - auto diffHook = settings.diffHook; - if (diffHook != "" && settings.runDiffHook) { - try { - RunOptions diffHookOptions(diffHook,{tryA, tryB, drvPath, tmpDir}); - diffHookOptions.searchPath = true; - diffHookOptions.uid = uid; - diffHookOptions.gid = gid; - diffHookOptions.chdir = "/"; - - auto diffRes = runProgram(diffHookOptions); - if (!statusOk(diffRes.first)) - throw ExecError(diffRes.first, - "diff-hook program '%1%' %2%", - diffHook, - statusToString(diffRes.first)); - - if (diffRes.second != "") - printError(chomp(diffRes.second)); - } catch (Error & error) { - ErrorInfo ei = error.info(); - ei.hint = hintfmt("diff hook execution failed: %s", - (error.info().hint.has_value() ? error.info().hint->str() : "")); - logError(ei); - } - } -} - -////////////////////////////////////////////////////////////////////// - - -class UserLock -{ -private: - Path fnUserLock; - AutoCloseFD fdUserLock; - - bool isEnabled = false; - string user; - uid_t uid = 0; - gid_t gid = 0; - std::vector supplementaryGIDs; - -public: - UserLock(); - - void kill(); - - string getUser() { return user; } - uid_t getUID() { assert(uid); return uid; } - uid_t getGID() { assert(gid); return gid; } - std::vector getSupplementaryGIDs() { return supplementaryGIDs; } - - bool findFreeUser(); - - bool enabled() { return isEnabled; } - -}; - - -UserLock::UserLock() -{ - assert(settings.buildUsersGroup != ""); - createDirs(settings.nixStateDir + "/userpool"); -} - -bool UserLock::findFreeUser() { - if (enabled()) return true; - - /* Get the members of the build-users-group. */ - struct group * gr = getgrnam(settings.buildUsersGroup.get().c_str()); - if (!gr) - throw Error("the group '%1%' specified in 'build-users-group' does not exist", - settings.buildUsersGroup); - gid = gr->gr_gid; - - /* Copy the result of getgrnam. */ - Strings users; - for (char * * p = gr->gr_mem; *p; ++p) { - debug("found build user '%1%'", *p); - users.push_back(*p); - } - - if (users.empty()) - throw Error("the build users group '%1%' has no members", - settings.buildUsersGroup); - - /* Find a user account that isn't currently in use for another - build. */ - for (auto & i : users) { - debug("trying user '%1%'", i); - - struct passwd * pw = getpwnam(i.c_str()); - if (!pw) - throw Error("the user '%1%' in the group '%2%' does not exist", - i, settings.buildUsersGroup); - - - fnUserLock = (format("%1%/userpool/%2%") % settings.nixStateDir % pw->pw_uid).str(); - - AutoCloseFD fd = open(fnUserLock.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0600); - if (!fd) - throw SysError("opening user lock '%1%'", fnUserLock); - - if (lockFile(fd.get(), ltWrite, false)) { - fdUserLock = std::move(fd); - user = i; - uid = pw->pw_uid; - - /* Sanity check... */ - if (uid == getuid() || uid == geteuid()) - throw Error("the Nix user should not be a member of '%1%'", - settings.buildUsersGroup); - -#if __linux__ - /* Get the list of supplementary groups of this build user. This - is usually either empty or contains a group such as "kvm". */ - supplementaryGIDs.resize(10); - int ngroups = supplementaryGIDs.size(); - int err = getgrouplist(pw->pw_name, pw->pw_gid, - supplementaryGIDs.data(), &ngroups); - if (err == -1) - throw Error("failed to get list of supplementary groups for '%1%'", pw->pw_name); - - supplementaryGIDs.resize(ngroups); -#endif - - isEnabled = true; - return true; - } - } - - return false; -} - -void UserLock::kill() -{ - killUser(uid); -} - - -////////////////////////////////////////////////////////////////////// - - -struct HookInstance -{ - /* Pipes for talking to the build hook. */ - Pipe toHook; - - /* Pipe for the hook's standard output/error. */ - Pipe fromHook; - - /* Pipe for the builder's standard output/error. */ - Pipe builderOut; - - /* The process ID of the hook. */ - Pid pid; - - FdSink sink; - - std::map activities; - - HookInstance(); - - ~HookInstance(); -}; - - -HookInstance::HookInstance() -{ - debug("starting build hook '%s'", settings.buildHook); - - /* Create a pipe to get the output of the child. */ - fromHook.create(); - - /* Create the communication pipes. */ - toHook.create(); - - /* Create a pipe to get the output of the builder. */ - builderOut.create(); - - /* Fork the hook. */ - pid = startProcess([&]() { - - commonChildInit(fromHook); - - if (chdir("/") == -1) throw SysError("changing into /"); - - /* Dup the communication pipes. */ - if (dup2(toHook.readSide.get(), STDIN_FILENO) == -1) - throw SysError("dupping to-hook read side"); - - /* Use fd 4 for the builder's stdout/stderr. */ - if (dup2(builderOut.writeSide.get(), 4) == -1) - throw SysError("dupping builder's stdout/stderr"); - - /* Hack: pass the read side of that fd to allow build-remote - to read SSH error messages. */ - if (dup2(builderOut.readSide.get(), 5) == -1) - throw SysError("dupping builder's stdout/stderr"); - - Strings args = { - std::string(baseNameOf(settings.buildHook.get())), - std::to_string(verbosity), - }; - - execv(settings.buildHook.get().c_str(), stringsToCharPtrs(args).data()); - - throw SysError("executing '%s'", settings.buildHook); - }); - - pid.setSeparatePG(true); - fromHook.writeSide = -1; - toHook.readSide = -1; - - sink = FdSink(toHook.writeSide.get()); - std::map settings; - globalConfig.getSettings(settings); - for (auto & setting : settings) - sink << 1 << setting.first << setting.second.value; - sink << 0; -} - - -HookInstance::~HookInstance() -{ - try { - toHook.writeSide = -1; - if (pid != -1) pid.kill(); - } catch (...) { - ignoreException(); - } -} - - -////////////////////////////////////////////////////////////////////// - - -typedef enum {rpAccept, rpDecline, rpPostpone} HookReply; - -class SubstitutionGoal; - -/* Unless we are repairing, we don't both to test validity and just assume it, - so the choices are `Absent` or `Valid`. */ -enum struct PathStatus { - Corrupt, - Absent, - Valid, -}; - -struct InitialOutputStatus { - StorePath path; - PathStatus status; - /* Valid in the store, and additionally non-corrupt if we are repairing */ - bool isValid() const { - return status == PathStatus::Valid; - } - /* Merely present, allowed to be corrupt */ - bool isPresent() const { - return status == PathStatus::Corrupt - || status == PathStatus::Valid; - } -}; - -struct InitialOutput { - bool wanted; - std::optional known; -}; - -class DerivationGoal : public Goal -{ -private: - /* Whether to use an on-disk .drv file. */ - bool useDerivation; - - /* The path of the derivation. */ - StorePath drvPath; - - /* The specific outputs that we need to build. Empty means all of - them. */ - StringSet wantedOutputs; - - /* Whether additional wanted outputs have been added. */ - bool needRestart = false; - - /* Whether to retry substituting the outputs after building the - inputs. */ - bool retrySubstitution; - - /* The derivation stored at drvPath. */ - std::unique_ptr drv; - - std::unique_ptr parsedDrv; - - /* The remainder is state held during the build. */ - - /* Locks on (fixed) output paths. */ - PathLocks outputLocks; - - /* All input paths (that is, the union of FS closures of the - immediate input paths). */ - StorePathSet inputPaths; - - std::map initialOutputs; - - /* User selected for running the builder. */ - std::unique_ptr buildUser; - - /* The process ID of the builder. */ - Pid pid; - - /* The temporary directory. */ - Path tmpDir; - - /* The path of the temporary directory in the sandbox. */ - Path tmpDirInSandbox; - - /* File descriptor for the log file. */ - AutoCloseFD fdLogFile; - std::shared_ptr logFileSink, logSink; - - /* Number of bytes received from the builder's stdout/stderr. */ - unsigned long logSize; - - /* The most recent log lines. */ - std::list logTail; - - std::string currentLogLine; - size_t currentLogLinePos = 0; // to handle carriage return - - std::string currentHookLine; - - /* Pipe for the builder's standard output/error. */ - Pipe builderOut; - - /* Pipe for synchronising updates to the builder namespaces. */ - Pipe userNamespaceSync; - - /* The mount namespace of the builder, used to add additional - paths to the sandbox as a result of recursive Nix calls. */ - AutoCloseFD sandboxMountNamespace; - - /* On Linux, whether we're doing the build in its own user - namespace. */ - bool usingUserNamespace = true; - - /* The build hook. */ - std::unique_ptr hook; - - /* Whether we're currently doing a chroot build. */ - bool useChroot = false; - - Path chrootRootDir; - - /* RAII object to delete the chroot directory. */ - std::shared_ptr autoDelChroot; - - /* The sort of derivation we are building. */ - DerivationType derivationType; - - /* Whether to run the build in a private network namespace. */ - bool privateNetwork = false; - - typedef void (DerivationGoal::*GoalState)(); - GoalState state; - - /* Stuff we need to pass to initChild(). */ - struct ChrootPath { - Path source; - bool optional; - ChrootPath(Path source = "", bool optional = false) - : source(source), optional(optional) - { } - }; - typedef map DirsInChroot; // maps target path to source path - DirsInChroot dirsInChroot; - - typedef map Environment; - Environment env; - -#if __APPLE__ - typedef string SandboxProfile; - SandboxProfile additionalSandboxProfile; -#endif - - /* Hash rewriting. */ - StringMap inputRewrites, outputRewrites; - typedef map RedirectedOutputs; - RedirectedOutputs redirectedOutputs; - - /* The outputs paths used during the build. - - - Input-addressed derivations or fixed content-addressed outputs are - sometimes built when some of their outputs already exist, and can not - be hidden via sandboxing. We use temporary locations instead and - rewrite after the build. Otherwise the regular predetermined paths are - put here. - - - Floating content-addressed derivations do not know their final build - output paths until the outputs are hashed, so random locations are - used, and then renamed. The randomness helps guard against hidden - self-references. - */ - OutputPathMap scratchOutputs; - - /* The final output paths of the build. - - - For input-addressed derivations, always the precomputed paths - - - For content-addressed derivations, calcuated from whatever the hash - ends up being. (Note that fixed outputs derivations that produce the - "wrong" output still install that data under its true content-address.) - */ - OutputPathMap finalOutputs; - - BuildMode buildMode; - - /* If we're repairing without a chroot, there may be outputs that - are valid but corrupt. So we redirect these outputs to - temporary paths. */ - StorePathSet redirectedBadOutputs; - - BuildResult result; - - /* The current round, if we're building multiple times. */ - size_t curRound = 1; - - size_t nrRounds; - - /* Path registration info from the previous round, if we're - building multiple times. Since this contains the hash, it - allows us to compare whether two rounds produced the same - result. */ - std::map prevInfos; - - uid_t sandboxUid() { return usingUserNamespace ? 1000 : buildUser->getUID(); } - gid_t sandboxGid() { return usingUserNamespace ? 100 : buildUser->getGID(); } - - const static Path homeDir; - - std::unique_ptr> mcExpectedBuilds, mcRunningBuilds; - - std::unique_ptr act; - - /* Activity that denotes waiting for a lock. */ - std::unique_ptr actLock; - - std::map builderActivities; - - /* The remote machine on which we're building. */ - std::string machineName; - - /* The recursive Nix daemon socket. */ - AutoCloseFD daemonSocket; - - /* The daemon main thread. */ - std::thread daemonThread; - - /* The daemon worker threads. */ - std::vector daemonWorkerThreads; - - /* Paths that were added via recursive Nix calls. */ - StorePathSet addedPaths; - - /* Recursive Nix calls are only allowed to build or realize paths - in the original input closure or added via a recursive Nix call - (so e.g. you can't do 'nix-store -r /nix/store/' where - /nix/store/ is some arbitrary path in a binary cache). */ - bool isAllowed(const StorePath & path) - { - return inputPaths.count(path) || addedPaths.count(path); - } - - friend struct RestrictedStore; - -public: - DerivationGoal(const StorePath & drvPath, - const StringSet & wantedOutputs, Worker & worker, - BuildMode buildMode = bmNormal); - DerivationGoal(const StorePath & drvPath, const BasicDerivation & drv, - const StringSet & wantedOutputs, Worker & worker, - BuildMode buildMode = bmNormal); - ~DerivationGoal(); - - /* Whether we need to perform hash rewriting if there are valid output paths. */ - bool needsHashRewrite(); - - void timedOut(Error && ex) override; - - string key() override - { - /* Ensure that derivations get built in order of their name, - i.e. a derivation named "aardvark" always comes before - "baboon". And substitution goals always happen before - derivation goals (due to "b$"). */ - return "b$" + std::string(drvPath.name()) + "$" + worker.store.printStorePath(drvPath); - } - - void work() override; - - StorePath getDrvPath() - { - return drvPath; - } - - /* Add wanted outputs to an already existing derivation goal. */ - void addWantedOutputs(const StringSet & outputs); - - BuildResult getResult() { return result; } - -private: - /* The states. */ - void getDerivation(); - void loadDerivation(); - void haveDerivation(); - void outputsSubstitutionTried(); - void gaveUpOnSubstitution(); - void closureRepaired(); - void inputsRealised(); - void tryToBuild(); - void tryLocalBuild(); - void buildDone(); - - void resolvedFinished(); - - /* Is the build hook willing to perform the build? */ - HookReply tryBuildHook(); - - /* Start building a derivation. */ - void startBuilder(); - - /* Fill in the environment for the builder. */ - void initEnv(); - - /* Setup tmp dir location. */ - void initTmpDir(); - - /* Write a JSON file containing the derivation attributes. */ - void writeStructuredAttrs(); - - void startDaemon(); - - void stopDaemon(); - - /* Add 'path' to the set of paths that may be referenced by the - outputs, and make it appear in the sandbox. */ - void addDependency(const StorePath & path); - - /* Make a file owned by the builder. */ - void chownToBuilder(const Path & path); - - /* Run the builder's process. */ - void runChild(); - - friend int childEntry(void *); - - /* Check that the derivation outputs all exist and register them - as valid. */ - void registerOutputs(); - - /* Check that an output meets the requirements specified by the - 'outputChecks' attribute (or the legacy - '{allowed,disallowed}{References,Requisites}' attributes). */ - void checkOutputs(const std::map & outputs); - - /* Open a log file and a pipe to it. */ - Path openLogFile(); - - /* Close the log file. */ - void closeLogFile(); - - /* Delete the temporary directory, if we have one. */ - void deleteTmpDir(bool force); - - /* Callback used by the worker to write to the log. */ - void handleChildOutput(int fd, const string & data) override; - void handleEOF(int fd) override; - void flushLine(); - - /* Wrappers around the corresponding Store methods that first consult the - derivation. This is currently needed because when there is no drv file - there also is no DB entry. */ - std::map> queryPartialDerivationOutputMap(); - OutputPathMap queryDerivationOutputMap(); - - /* Return the set of (in)valid paths. */ - void checkPathValidity(); - - /* Forcibly kill the child process, if any. */ - void killChild(); - - /* Create alternative path calculated from but distinct from the - input, so we can avoid overwriting outputs (or other store paths) - that already exist. */ - StorePath makeFallbackPath(const StorePath & path); - /* Make a path to another based on the output name along with the - derivation hash. */ - /* FIXME add option to randomize, so we can audit whether our - rewrites caught everything */ - StorePath makeFallbackPath(std::string_view outputName); - - void repairClosure(); - - void started(); - - void done( - BuildResult::Status status, - std::optional ex = {}); - - StorePathSet exportReferences(const StorePathSet & storePaths); -}; - - -const Path DerivationGoal::homeDir = "/homeless-shelter"; - - -DerivationGoal::DerivationGoal(const StorePath & drvPath, - const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode) - : Goal(worker) - , useDerivation(true) - , drvPath(drvPath) - , wantedOutputs(wantedOutputs) - , buildMode(buildMode) -{ - state = &DerivationGoal::getDerivation; - name = fmt( - "building of '%s' from .drv file", - StorePathWithOutputs { drvPath, wantedOutputs }.to_string(worker.store)); - trace("created"); - - mcExpectedBuilds = std::make_unique>(worker.expectedBuilds); - worker.updateProgress(); -} - - -DerivationGoal::DerivationGoal(const StorePath & drvPath, const BasicDerivation & drv, - const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode) - : Goal(worker) - , useDerivation(false) - , drvPath(drvPath) - , wantedOutputs(wantedOutputs) - , buildMode(buildMode) -{ - this->drv = std::make_unique(BasicDerivation(drv)); - state = &DerivationGoal::haveDerivation; - name = fmt( - "building of '%s' from in-memory derivation", - StorePathWithOutputs { drvPath, drv.outputNames() }.to_string(worker.store)); - trace("created"); - - mcExpectedBuilds = std::make_unique>(worker.expectedBuilds); - worker.updateProgress(); - - /* Prevent the .chroot directory from being - garbage-collected. (See isActiveTempFile() in gc.cc.) */ - worker.store.addTempRoot(this->drvPath); -} - - -DerivationGoal::~DerivationGoal() -{ - /* Careful: we should never ever throw an exception from a - destructor. */ - try { killChild(); } catch (...) { ignoreException(); } - try { stopDaemon(); } catch (...) { ignoreException(); } - try { deleteTmpDir(false); } catch (...) { ignoreException(); } - try { closeLogFile(); } catch (...) { ignoreException(); } -} - - -inline bool DerivationGoal::needsHashRewrite() -{ -#if __linux__ - return !useChroot; -#else - /* Darwin requires hash rewriting even when sandboxing is enabled. */ - return true; -#endif -} - - -void DerivationGoal::killChild() -{ - if (pid != -1) { - worker.childTerminated(this); - - if (buildUser) { - /* If we're using a build user, then there is a tricky - race condition: if we kill the build user before the - child has done its setuid() to the build user uid, then - it won't be killed, and we'll potentially lock up in - pid.wait(). So also send a conventional kill to the - child. */ - ::kill(-pid, SIGKILL); /* ignore the result */ - buildUser->kill(); - pid.wait(); - } else - pid.kill(); - - assert(pid == -1); - } - - hook.reset(); -} - - -void DerivationGoal::timedOut(Error && ex) -{ - killChild(); - done(BuildResult::TimedOut, ex); -} - - -void DerivationGoal::work() -{ - (this->*state)(); -} - - -void DerivationGoal::addWantedOutputs(const StringSet & outputs) -{ - /* If we already want all outputs, there is nothing to do. */ - if (wantedOutputs.empty()) return; - - if (outputs.empty()) { - wantedOutputs.clear(); - needRestart = true; - } else - for (auto & i : outputs) - if (wantedOutputs.insert(i).second) - needRestart = true; -} - - -void DerivationGoal::getDerivation() -{ - trace("init"); - - /* The first thing to do is to make sure that the derivation - exists. If it doesn't, it may be created through a - substitute. */ - if (buildMode == bmNormal && worker.store.isValidPath(drvPath)) { - loadDerivation(); - return; - } - - addWaitee(worker.makeSubstitutionGoal(drvPath)); - - state = &DerivationGoal::loadDerivation; -} - - -void DerivationGoal::loadDerivation() -{ - trace("loading derivation"); - - if (nrFailed != 0) { - done(BuildResult::MiscFailure, Error("cannot build missing derivation '%s'", worker.store.printStorePath(drvPath))); - return; - } - - /* `drvPath' should already be a root, but let's be on the safe - side: if the user forgot to make it a root, we wouldn't want - things being garbage collected while we're busy. */ - worker.store.addTempRoot(drvPath); - - assert(worker.store.isValidPath(drvPath)); - - /* Get the derivation. */ - drv = std::unique_ptr(new Derivation(worker.store.derivationFromPath(drvPath))); - - haveDerivation(); -} - - -void DerivationGoal::haveDerivation() -{ - trace("have derivation"); - - if (drv->type() == DerivationType::CAFloating) - settings.requireExperimentalFeature("ca-derivations"); - - retrySubstitution = false; - - for (auto & i : drv->outputsAndOptPaths(worker.store)) - if (i.second.second) - worker.store.addTempRoot(*i.second.second); - - /* Check what outputs paths are not already valid. */ - checkPathValidity(); - bool allValid = true; - for (auto & [_, status] : initialOutputs) { - if (!status.wanted) continue; - if (!status.known || !status.known->isValid()) { - allValid = false; - break; - } - } - - /* If they are all valid, then we're done. */ - if (allValid && buildMode == bmNormal) { - done(BuildResult::AlreadyValid); - return; - } - - parsedDrv = std::make_unique(drvPath, *drv); - - - /* We are first going to try to create the invalid output paths - through substitutes. If that doesn't work, we'll build - them. */ - if (settings.useSubstitutes && parsedDrv->substitutesAllowed()) - for (auto & [_, status] : initialOutputs) { - if (!status.wanted) continue; - if (!status.known) { - warn("do not know how to query for unknown floating content-addressed derivation output yet"); - /* Nothing to wait for; tail call */ - return DerivationGoal::gaveUpOnSubstitution(); - } - addWaitee(worker.makeSubstitutionGoal( - status.known->path, - buildMode == bmRepair ? Repair : NoRepair, - getDerivationCA(*drv))); - } - - if (waitees.empty()) /* to prevent hang (no wake-up event) */ - outputsSubstitutionTried(); - else - state = &DerivationGoal::outputsSubstitutionTried; -} - - -void DerivationGoal::outputsSubstitutionTried() -{ - trace("all outputs substituted (maybe)"); - - if (nrFailed > 0 && nrFailed > nrNoSubstituters + nrIncompleteClosure && !settings.tryFallback) { - done(BuildResult::TransientFailure, - fmt("some substitutes for the outputs of derivation '%s' failed (usually happens due to networking issues); try '--fallback' to build derivation from source ", - worker.store.printStorePath(drvPath))); - return; - } - - /* If the substitutes form an incomplete closure, then we should - build the dependencies of this derivation, but after that, we - can still use the substitutes for this derivation itself. */ - if (nrIncompleteClosure > 0) retrySubstitution = true; - - nrFailed = nrNoSubstituters = nrIncompleteClosure = 0; - - if (needRestart) { - needRestart = false; - haveDerivation(); - return; - } - - checkPathValidity(); - size_t nrInvalid = 0; - for (auto & [_, status] : initialOutputs) { - if (!status.wanted) continue; - if (!status.known || !status.known->isValid()) - nrInvalid++; - } - - if (buildMode == bmNormal && nrInvalid == 0) { - done(BuildResult::Substituted); - return; - } - if (buildMode == bmRepair && nrInvalid == 0) { - repairClosure(); - return; - } - if (buildMode == bmCheck && nrInvalid > 0) - throw Error("some outputs of '%s' are not valid, so checking is not possible", - worker.store.printStorePath(drvPath)); - - /* Nothing to wait for; tail call */ - gaveUpOnSubstitution(); -} - -/* At least one of the output paths could not be - produced using a substitute. So we have to build instead. */ -void DerivationGoal::gaveUpOnSubstitution() -{ - /* Make sure checkPathValidity() from now on checks all - outputs. */ - wantedOutputs.clear(); - - /* The inputs must be built before we can build this goal. */ - if (useDerivation) - for (auto & i : dynamic_cast(drv.get())->inputDrvs) - addWaitee(worker.makeDerivationGoal(i.first, i.second, buildMode == bmRepair ? bmRepair : bmNormal)); - - for (auto & i : drv->inputSrcs) { - if (worker.store.isValidPath(i)) continue; - if (!settings.useSubstitutes) - throw Error("dependency '%s' of '%s' does not exist, and substitution is disabled", - worker.store.printStorePath(i), worker.store.printStorePath(drvPath)); - addWaitee(worker.makeSubstitutionGoal(i)); - } - - if (waitees.empty()) /* to prevent hang (no wake-up event) */ - inputsRealised(); - else - state = &DerivationGoal::inputsRealised; -} - - -void DerivationGoal::repairClosure() -{ - /* If we're repairing, we now know that our own outputs are valid. - Now check whether the other paths in the outputs closure are - good. If not, then start derivation goals for the derivations - that produced those outputs. */ - - /* Get the output closure. */ - auto outputs = queryDerivationOutputMap(); - StorePathSet outputClosure; - for (auto & i : outputs) { - if (!wantOutput(i.first, wantedOutputs)) continue; - worker.store.computeFSClosure(i.second, outputClosure); - } - - /* Filter out our own outputs (which we have already checked). */ - for (auto & i : outputs) - outputClosure.erase(i.second); - - /* Get all dependencies of this derivation so that we know which - derivation is responsible for which path in the output - closure. */ - StorePathSet inputClosure; - if (useDerivation) worker.store.computeFSClosure(drvPath, inputClosure); - std::map outputsToDrv; - for (auto & i : inputClosure) - if (i.isDerivation()) { - auto depOutputs = worker.store.queryPartialDerivationOutputMap(i); - for (auto & j : depOutputs) - if (j.second) - outputsToDrv.insert_or_assign(*j.second, i); - } - - /* Check each path (slow!). */ - for (auto & i : outputClosure) { - if (worker.pathContentsGood(i)) continue; - logError({ - .name = "Corrupt path in closure", - .hint = hintfmt( - "found corrupted or missing path '%s' in the output closure of '%s'", - worker.store.printStorePath(i), worker.store.printStorePath(drvPath)) - }); - auto drvPath2 = outputsToDrv.find(i); - if (drvPath2 == outputsToDrv.end()) - addWaitee(worker.makeSubstitutionGoal(i, Repair)); - else - addWaitee(worker.makeDerivationGoal(drvPath2->second, StringSet(), bmRepair)); - } - - if (waitees.empty()) { - done(BuildResult::AlreadyValid); - return; - } - - state = &DerivationGoal::closureRepaired; -} - - -void DerivationGoal::closureRepaired() -{ - trace("closure repaired"); - if (nrFailed > 0) - throw Error("some paths in the output closure of derivation '%s' could not be repaired", - worker.store.printStorePath(drvPath)); - done(BuildResult::AlreadyValid); -} - - -void DerivationGoal::inputsRealised() -{ - trace("all inputs realised"); - - if (nrFailed != 0) { - if (!useDerivation) - throw Error("some dependencies of '%s' are missing", worker.store.printStorePath(drvPath)); - done(BuildResult::DependencyFailed, Error( - "%s dependencies of derivation '%s' failed to build", - nrFailed, worker.store.printStorePath(drvPath))); - return; - } - - if (retrySubstitution) { - haveDerivation(); - return; - } - - /* Gather information necessary for computing the closure and/or - running the build hook. */ - - /* Determine the full set of input paths. */ - - /* First, the input derivations. */ - if (useDerivation) { - auto & fullDrv = *dynamic_cast(drv.get()); - - if (!fullDrv.inputDrvs.empty() && fullDrv.type() == DerivationType::CAFloating) { - /* We are be able to resolve this derivation based on the - now-known results of dependencies. If so, we become a stub goal - aliasing that resolved derivation goal */ - std::optional attempt = fullDrv.tryResolve(worker.store); - assert(attempt); - Derivation drvResolved { *std::move(attempt) }; - - auto pathResolved = writeDerivation(worker.store, drvResolved); - /* Add to memotable to speed up downstream goal's queries with the - original derivation. */ - drvPathResolutions.lock()->insert_or_assign(drvPath, pathResolved); - - auto msg = fmt("Resolved derivation: '%s' -> '%s'", - worker.store.printStorePath(drvPath), - worker.store.printStorePath(pathResolved)); - act = std::make_unique(*logger, lvlInfo, actBuildWaiting, msg, - Logger::Fields { - worker.store.printStorePath(drvPath), - worker.store.printStorePath(pathResolved), - }); - - auto resolvedGoal = worker.makeDerivationGoal( - pathResolved, wantedOutputs, buildMode); - addWaitee(resolvedGoal); - - state = &DerivationGoal::resolvedFinished; - return; - } - - for (auto & [depDrvPath, wantedDepOutputs] : fullDrv.inputDrvs) { - /* Add the relevant output closures of the input derivation - `i' as input paths. Only add the closures of output paths - that are specified as inputs. */ - assert(worker.store.isValidPath(drvPath)); - auto outputs = worker.store.queryPartialDerivationOutputMap(depDrvPath); - for (auto & j : wantedDepOutputs) { - if (outputs.count(j) > 0) { - auto optRealizedInput = outputs.at(j); - if (!optRealizedInput) - throw Error( - "derivation '%s' requires output '%s' from input derivation '%s', which is supposedly realized already, yet we still don't know what path corresponds to that output", - worker.store.printStorePath(drvPath), j, worker.store.printStorePath(drvPath)); - worker.store.computeFSClosure(*optRealizedInput, inputPaths); - } else - throw Error( - "derivation '%s' requires non-existent output '%s' from input derivation '%s'", - worker.store.printStorePath(drvPath), j, worker.store.printStorePath(drvPath)); - } - } - } - - /* Second, the input sources. */ - worker.store.computeFSClosure(drv->inputSrcs, inputPaths); - - debug("added input paths %s", worker.store.showPaths(inputPaths)); - - /* What type of derivation are we building? */ - derivationType = drv->type(); - - /* Don't repeat fixed-output derivations since they're already - verified by their output hash.*/ - nrRounds = derivationIsFixed(derivationType) ? 1 : settings.buildRepeat + 1; - - /* Okay, try to build. Note that here we don't wait for a build - slot to become available, since we don't need one if there is a - build hook. */ - state = &DerivationGoal::tryToBuild; - worker.wakeUp(shared_from_this()); - - result = BuildResult(); -} - -void DerivationGoal::started() { - auto msg = fmt( - buildMode == bmRepair ? "repairing outputs of '%s'" : - buildMode == bmCheck ? "checking outputs of '%s'" : - nrRounds > 1 ? "building '%s' (round %d/%d)" : - "building '%s'", worker.store.printStorePath(drvPath), curRound, nrRounds); - fmt("building '%s'", worker.store.printStorePath(drvPath)); - if (hook) msg += fmt(" on '%s'", machineName); - act = std::make_unique(*logger, lvlInfo, actBuild, msg, - Logger::Fields{worker.store.printStorePath(drvPath), hook ? machineName : "", curRound, nrRounds}); - mcRunningBuilds = std::make_unique>(worker.runningBuilds); - worker.updateProgress(); -} - -void DerivationGoal::tryToBuild() -{ - trace("trying to build"); - - /* Obtain locks on all output paths, if the paths are known a priori. - - The locks are automatically released when we exit this function or Nix - crashes. If we can't acquire the lock, then continue; hopefully some - other goal can start a build, and if not, the main loop will sleep a few - seconds and then retry this goal. */ - PathSet lockFiles; - /* FIXME: Should lock something like the drv itself so we don't build same - CA drv concurrently */ - for (auto & i : drv->outputsAndOptPaths(worker.store)) - if (i.second.second) - lockFiles.insert(worker.store.Store::toRealPath(*i.second.second)); - - if (!outputLocks.lockPaths(lockFiles, "", false)) { - if (!actLock) - actLock = std::make_unique(*logger, lvlWarn, actBuildWaiting, - fmt("waiting for lock on %s", yellowtxt(showPaths(lockFiles)))); - worker.waitForAWhile(shared_from_this()); - return; - } - - actLock.reset(); - - /* Now check again whether the outputs are valid. This is because - another process may have started building in parallel. After - it has finished and released the locks, we can (and should) - reuse its results. (Strictly speaking the first check can be - omitted, but that would be less efficient.) Note that since we - now hold the locks on the output paths, no other process can - build this derivation, so no further checks are necessary. */ - checkPathValidity(); - bool allValid = true; - for (auto & [_, status] : initialOutputs) { - if (!status.wanted) continue; - if (!status.known || !status.known->isValid()) { - allValid = false; - break; - } - } - if (buildMode != bmCheck && allValid) { - debug("skipping build of derivation '%s', someone beat us to it", worker.store.printStorePath(drvPath)); - outputLocks.setDeletion(true); - done(BuildResult::AlreadyValid); - return; - } - - /* If any of the outputs already exist but are not valid, delete - them. */ - for (auto & [_, status] : initialOutputs) { - if (!status.known || status.known->isValid()) continue; - auto storePath = status.known->path; - debug("removing invalid path '%s'", worker.store.printStorePath(status.known->path)); - deletePath(worker.store.Store::toRealPath(storePath)); - } - - /* Don't do a remote build if the derivation has the attribute - `preferLocalBuild' set. Also, check and repair modes are only - supported for local builds. */ - bool buildLocally = buildMode != bmNormal || parsedDrv->willBuildLocally(worker.store); - - if (!buildLocally) { - switch (tryBuildHook()) { - case rpAccept: - /* Yes, it has started doing so. Wait until we get - EOF from the hook. */ - actLock.reset(); - result.startTime = time(0); // inexact - state = &DerivationGoal::buildDone; - started(); - return; - case rpPostpone: - /* Not now; wait until at least one child finishes or - the wake-up timeout expires. */ - if (!actLock) - actLock = std::make_unique(*logger, lvlWarn, actBuildWaiting, - fmt("waiting for a machine to build '%s'", yellowtxt(worker.store.printStorePath(drvPath)))); - worker.waitForAWhile(shared_from_this()); - outputLocks.unlock(); - return; - case rpDecline: - /* We should do it ourselves. */ - break; - } - } - - actLock.reset(); - - state = &DerivationGoal::tryLocalBuild; - worker.wakeUp(shared_from_this()); -} - -void DerivationGoal::tryLocalBuild() { - bool buildLocally = buildMode != bmNormal || parsedDrv->willBuildLocally(worker.store); - - /* Make sure that we are allowed to start a build. If this - derivation prefers to be done locally, do it even if - maxBuildJobs is 0. */ - unsigned int curBuilds = worker.getNrLocalBuilds(); - if (curBuilds >= settings.maxBuildJobs && !(buildLocally && curBuilds == 0)) { - worker.waitForBuildSlot(shared_from_this()); - outputLocks.unlock(); - return; - } - - /* If `build-users-group' is not empty, then we have to build as - one of the members of that group. */ - if (settings.buildUsersGroup != "" && getuid() == 0) { -#if defined(__linux__) || defined(__APPLE__) - if (!buildUser) buildUser = std::make_unique(); - - if (buildUser->findFreeUser()) { - /* Make sure that no other processes are executing under this - uid. */ - buildUser->kill(); - } else { - if (!actLock) - actLock = std::make_unique(*logger, lvlWarn, actBuildWaiting, - fmt("waiting for UID to build '%s'", yellowtxt(worker.store.printStorePath(drvPath)))); - worker.waitForAWhile(shared_from_this()); - return; - } -#else - /* Don't know how to block the creation of setuid/setgid - binaries on this platform. */ - throw Error("build users are not supported on this platform for security reasons"); -#endif - } - - actLock.reset(); - - try { - - /* Okay, we have to build. */ - startBuilder(); - - } catch (BuildError & e) { - outputLocks.unlock(); - buildUser.reset(); - worker.permanentFailure = true; - done(BuildResult::InputRejected, e); - return; - } - - /* This state will be reached when we get EOF on the child's - log pipe. */ - state = &DerivationGoal::buildDone; - - started(); -} - - -static void chmod_(const Path & path, mode_t mode) -{ - if (chmod(path.c_str(), mode) == -1) - throw SysError("setting permissions on '%s'", path); -} - - -/* Move/rename path 'src' to 'dst'. Temporarily make 'src' writable if - it's a directory and we're not root (to be able to update the - directory's parent link ".."). */ -static void movePath(const Path & src, const Path & dst) -{ - auto st = lstat(src); - - bool changePerm = (geteuid() && S_ISDIR(st.st_mode) && !(st.st_mode & S_IWUSR)); - - if (changePerm) - chmod_(src, st.st_mode | S_IWUSR); - - if (rename(src.c_str(), dst.c_str())) - throw SysError("renaming '%1%' to '%2%'", src, dst); - - if (changePerm) - chmod_(dst, st.st_mode); -} - - -void replaceValidPath(const Path & storePath, const Path & tmpPath) -{ - /* We can't atomically replace storePath (the original) with - tmpPath (the replacement), so we have to move it out of the - way first. We'd better not be interrupted here, because if - we're repairing (say) Glibc, we end up with a broken system. */ - Path oldPath = (format("%1%.old-%2%-%3%") % storePath % getpid() % random()).str(); - if (pathExists(storePath)) - movePath(storePath, oldPath); - - try { - movePath(tmpPath, storePath); - } catch (...) { - try { - // attempt to recover - movePath(oldPath, storePath); - } catch (...) { - ignoreException(); - } - throw; - } - - deletePath(oldPath); -} - - -MakeError(NotDeterministic, BuildError); - - -void DerivationGoal::buildDone() -{ - trace("build done"); - - /* Release the build user at the end of this function. We don't do - it right away because we don't want another build grabbing this - uid and then messing around with our output. */ - Finally releaseBuildUser([&]() { buildUser.reset(); }); - - sandboxMountNamespace = -1; - - /* Since we got an EOF on the logger pipe, the builder is presumed - to have terminated. In fact, the builder could also have - simply have closed its end of the pipe, so just to be sure, - kill it. */ - int status = hook ? hook->pid.kill() : pid.kill(); - - debug("builder process for '%s' finished", worker.store.printStorePath(drvPath)); - - result.timesBuilt++; - result.stopTime = time(0); - - /* So the child is gone now. */ - worker.childTerminated(this); - - /* Close the read side of the logger pipe. */ - if (hook) { - hook->builderOut.readSide = -1; - hook->fromHook.readSide = -1; - } else - builderOut.readSide = -1; - - /* Close the log file. */ - closeLogFile(); - - /* When running under a build user, make sure that all processes - running under that uid are gone. This is to prevent a - malicious user from leaving behind a process that keeps files - open and modifies them after they have been chown'ed to - root. */ - if (buildUser) buildUser->kill(); - - /* Terminate the recursive Nix daemon. */ - stopDaemon(); - - bool diskFull = false; - - try { - - /* Check the exit status. */ - if (!statusOk(status)) { - - /* Heuristically check whether the build failure may have - been caused by a disk full condition. We have no way - of knowing whether the build actually got an ENOSPC. - So instead, check if the disk is (nearly) full now. If - so, we don't mark this build as a permanent failure. */ -#if HAVE_STATVFS - uint64_t required = 8ULL * 1024 * 1024; // FIXME: make configurable - struct statvfs st; - if (statvfs(worker.store.realStoreDir.c_str(), &st) == 0 && - (uint64_t) st.f_bavail * st.f_bsize < required) - diskFull = true; - if (statvfs(tmpDir.c_str(), &st) == 0 && - (uint64_t) st.f_bavail * st.f_bsize < required) - diskFull = true; -#endif - - deleteTmpDir(false); - - /* Move paths out of the chroot for easier debugging of - build failures. */ - if (useChroot && buildMode == bmNormal) - for (auto & [_, status] : initialOutputs) { - if (!status.known) continue; - if (buildMode != bmCheck && status.known->isValid()) continue; - auto p = worker.store.printStorePath(status.known->path); - if (pathExists(chrootRootDir + p)) - rename((chrootRootDir + p).c_str(), p.c_str()); - } - - auto msg = fmt("builder for '%s' %s", - yellowtxt(worker.store.printStorePath(drvPath)), - statusToString(status)); - - if (!logger->isVerbose() && !logTail.empty()) { - msg += (format("; last %d log lines:") % logTail.size()).str(); - for (auto & line : logTail) - msg += "\n " + line; - } - - if (diskFull) - msg += "\nnote: build failure may have been caused by lack of free disk space"; - - throw BuildError(msg); - } - - /* Compute the FS closure of the outputs and register them as - being valid. */ - registerOutputs(); - - if (settings.postBuildHook != "") { - Activity act(*logger, lvlInfo, actPostBuildHook, - fmt("running post-build-hook '%s'", settings.postBuildHook), - Logger::Fields{worker.store.printStorePath(drvPath)}); - PushActivity pact(act.id); - StorePathSet outputPaths; - for (auto i : drv->outputs) { - outputPaths.insert(finalOutputs.at(i.first)); - } - std::map hookEnvironment = getEnv(); - - hookEnvironment.emplace("DRV_PATH", worker.store.printStorePath(drvPath)); - hookEnvironment.emplace("OUT_PATHS", chomp(concatStringsSep(" ", worker.store.printStorePathSet(outputPaths)))); - - RunOptions opts(settings.postBuildHook, {}); - opts.environment = hookEnvironment; - - struct LogSink : Sink { - Activity & act; - std::string currentLine; - - LogSink(Activity & act) : act(act) { } - - void operator() (const unsigned char * data, size_t len) override { - for (size_t i = 0; i < len; i++) { - auto c = data[i]; - - if (c == '\n') { - flushLine(); - } else { - currentLine += c; - } - } - } - - void flushLine() { - act.result(resPostBuildLogLine, currentLine); - currentLine.clear(); - } - - ~LogSink() { - if (currentLine != "") { - currentLine += '\n'; - flushLine(); - } - } - }; - LogSink sink(act); - - opts.standardOut = &sink; - opts.mergeStderrToStdout = true; - runProgram2(opts); - } - - if (buildMode == bmCheck) { - deleteTmpDir(true); - done(BuildResult::Built); - return; - } - - /* Delete unused redirected outputs (when doing hash rewriting). */ - for (auto & i : redirectedOutputs) - deletePath(worker.store.Store::toRealPath(i.second)); - - /* Delete the chroot (if we were using one). */ - autoDelChroot.reset(); /* this runs the destructor */ - - deleteTmpDir(true); - - /* Repeat the build if necessary. */ - if (curRound++ < nrRounds) { - outputLocks.unlock(); - state = &DerivationGoal::tryToBuild; - worker.wakeUp(shared_from_this()); - return; - } - - /* It is now safe to delete the lock files, since all future - lockers will see that the output paths are valid; they will - not create new lock files with the same names as the old - (unlinked) lock files. */ - outputLocks.setDeletion(true); - outputLocks.unlock(); - - } catch (BuildError & e) { - outputLocks.unlock(); - - BuildResult::Status st = BuildResult::MiscFailure; - - if (hook && WIFEXITED(status) && WEXITSTATUS(status) == 101) - st = BuildResult::TimedOut; - - else if (hook && (!WIFEXITED(status) || WEXITSTATUS(status) != 100)) { - } - - else { - st = - dynamic_cast(&e) ? BuildResult::NotDeterministic : - statusOk(status) ? BuildResult::OutputRejected : - derivationIsImpure(derivationType) || diskFull ? BuildResult::TransientFailure : - BuildResult::PermanentFailure; - } - - done(st, e); - return; - } - - done(BuildResult::Built); -} - -void DerivationGoal::resolvedFinished() { - done(BuildResult::Built); -} - -HookReply DerivationGoal::tryBuildHook() -{ - if (!worker.tryBuildHook || !useDerivation) return rpDecline; - - if (!worker.hook) - worker.hook = std::make_unique(); - - try { - - /* Send the request to the hook. */ - worker.hook->sink - << "try" - << (worker.getNrLocalBuilds() < settings.maxBuildJobs ? 1 : 0) - << drv->platform - << worker.store.printStorePath(drvPath) - << parsedDrv->getRequiredSystemFeatures(); - worker.hook->sink.flush(); - - /* Read the first line of input, which should be a word indicating - whether the hook wishes to perform the build. */ - string reply; - while (true) { - string s = readLine(worker.hook->fromHook.readSide.get()); - if (handleJSONLogMessage(s, worker.act, worker.hook->activities, true)) - ; - else if (string(s, 0, 2) == "# ") { - reply = string(s, 2); - break; - } - else { - s += "\n"; - writeToStderr(s); - } - } - - debug("hook reply is '%1%'", reply); - - if (reply == "decline") - return rpDecline; - else if (reply == "decline-permanently") { - worker.tryBuildHook = false; - worker.hook = 0; - return rpDecline; - } - else if (reply == "postpone") - return rpPostpone; - else if (reply != "accept") - throw Error("bad hook reply '%s'", reply); - - } catch (SysError & e) { - if (e.errNo == EPIPE) { - logError({ - .name = "Build hook died", - .hint = hintfmt( - "build hook died unexpectedly: %s", - chomp(drainFD(worker.hook->fromHook.readSide.get()))) - }); - worker.hook = 0; - return rpDecline; - } else - throw; - } - - hook = std::move(worker.hook); - - machineName = readLine(hook->fromHook.readSide.get()); - - /* Tell the hook all the inputs that have to be copied to the - remote system. */ - worker_proto::write(worker.store, hook->sink, inputPaths); - - /* Tell the hooks the missing outputs that have to be copied back - from the remote system. */ - { - StorePathSet missingPaths; - for (auto & [_, status] : initialOutputs) { - if (!status.known) continue; - if (buildMode != bmCheck && status.known->isValid()) continue; - missingPaths.insert(status.known->path); - } - worker_proto::write(worker.store, hook->sink, missingPaths); - } - - hook->sink = FdSink(); - hook->toHook.writeSide = -1; - - /* Create the log file and pipe. */ - Path logFile = openLogFile(); - - set fds; - fds.insert(hook->fromHook.readSide.get()); - fds.insert(hook->builderOut.readSide.get()); - worker.childStarted(shared_from_this(), fds, false, false); - - return rpAccept; -} - - -int childEntry(void * arg) -{ - ((DerivationGoal *) arg)->runChild(); - return 1; -} - - -StorePathSet DerivationGoal::exportReferences(const StorePathSet & storePaths) -{ - StorePathSet paths; - - for (auto & storePath : storePaths) { - if (!inputPaths.count(storePath)) - throw BuildError("cannot export references of path '%s' because it is not in the input closure of the derivation", worker.store.printStorePath(storePath)); - - worker.store.computeFSClosure({storePath}, paths); - } - - /* If there are derivations in the graph, then include their - outputs as well. This is useful if you want to do things - like passing all build-time dependencies of some path to a - derivation that builds a NixOS DVD image. */ - auto paths2 = paths; - - for (auto & j : paths2) { - if (j.isDerivation()) { - Derivation drv = worker.store.derivationFromPath(j); - for (auto & k : drv.outputsAndOptPaths(worker.store)) { - if (!k.second.second) - /* FIXME: I am confused why we are calling - `computeFSClosure` on the output path, rather than - derivation itself. That doesn't seem right to me, so I - won't try to implemented this for CA derivations. */ - throw UnimplementedError("exportReferences on CA derivations is not yet implemented"); - worker.store.computeFSClosure(*k.second.second, paths); - } - } - } - - return paths; -} - -static std::once_flag dns_resolve_flag; - -static void preloadNSS() { - /* builtin:fetchurl can trigger a DNS lookup, which with glibc can trigger a dynamic library load of - one of the glibc NSS libraries in a sandboxed child, which will fail unless the library's already - been loaded in the parent. So we force a lookup of an invalid domain to force the NSS machinery to - load its lookup libraries in the parent before any child gets a chance to. */ - std::call_once(dns_resolve_flag, []() { - struct addrinfo *res = NULL; - - if (getaddrinfo("this.pre-initializes.the.dns.resolvers.invalid.", "http", NULL, &res) != 0) { - if (res) freeaddrinfo(res); - } - }); -} - - -void linkOrCopy(const Path & from, const Path & to) -{ - if (link(from.c_str(), to.c_str()) == -1) { - /* Hard-linking fails if we exceed the maximum link count on a - file (e.g. 32000 of ext3), which is quite possible after a - 'nix-store --optimise'. FIXME: actually, why don't we just - bind-mount in this case? - - It can also fail with EPERM in BeegFS v7 and earlier versions - which don't allow hard-links to other directories */ - if (errno != EMLINK && errno != EPERM) - throw SysError("linking '%s' to '%s'", to, from); - copyPath(from, to); - } -} - - -void DerivationGoal::startBuilder() -{ - /* Right platform? */ - if (!parsedDrv->canBuildLocally(worker.store)) - throw Error("a '%s' with features {%s} is required to build '%s', but I am a '%s' with features {%s}", - drv->platform, - concatStringsSep(", ", parsedDrv->getRequiredSystemFeatures()), - worker.store.printStorePath(drvPath), - settings.thisSystem, - concatStringsSep(", ", worker.store.systemFeatures)); - - if (drv->isBuiltin()) - preloadNSS(); - -#if __APPLE__ - additionalSandboxProfile = parsedDrv->getStringAttr("__sandboxProfile").value_or(""); -#endif - - /* Are we doing a chroot build? */ - { - auto noChroot = parsedDrv->getBoolAttr("__noChroot"); - if (settings.sandboxMode == smEnabled) { - if (noChroot) - throw Error("derivation '%s' has '__noChroot' set, " - "but that's not allowed when 'sandbox' is 'true'", worker.store.printStorePath(drvPath)); -#if __APPLE__ - if (additionalSandboxProfile != "") - throw Error("derivation '%s' specifies a sandbox profile, " - "but this is only allowed when 'sandbox' is 'relaxed'", worker.store.printStorePath(drvPath)); -#endif - useChroot = true; - } - else if (settings.sandboxMode == smDisabled) - useChroot = false; - else if (settings.sandboxMode == smRelaxed) - useChroot = !(derivationIsImpure(derivationType)) && !noChroot; - } - - if (worker.store.storeDir != worker.store.realStoreDir) { - #if __linux__ - useChroot = true; - #else - throw Error("building using a diverted store is not supported on this platform"); - #endif - } - - /* Create a temporary directory where the build will take - place. */ - tmpDir = createTempDir("", "nix-build-" + std::string(drvPath.name()), false, false, 0700); - - chownToBuilder(tmpDir); - - for (auto & [outputName, status] : initialOutputs) { - /* Set scratch path we'll actually use during the build. - - If we're not doing a chroot build, but we have some valid - output paths. Since we can't just overwrite or delete - them, we have to do hash rewriting: i.e. in the - environment/arguments passed to the build, we replace the - hashes of the valid outputs with unique dummy strings; - after the build, we discard the redirected outputs - corresponding to the valid outputs, and rewrite the - contents of the new outputs to replace the dummy strings - with the actual hashes. */ - auto scratchPath = - !status.known - ? makeFallbackPath(outputName) - : !needsHashRewrite() - /* Can always use original path in sandbox */ - ? status.known->path - : !status.known->isPresent() - /* If path doesn't yet exist can just use it */ - ? status.known->path - : buildMode != bmRepair && !status.known->isValid() - /* If we aren't repairing we'll delete a corrupted path, so we - can use original path */ - ? status.known->path - : /* If we are repairing or the path is totally valid, we'll need - to use a temporary path */ - makeFallbackPath(status.known->path); - scratchOutputs.insert_or_assign(outputName, scratchPath); - - /* A non-removed corrupted path needs to be stored here, too */ - if (buildMode == bmRepair && !status.known->isValid()) - redirectedBadOutputs.insert(status.known->path); - - /* Substitute output placeholders with the scratch output paths. - We'll use during the build. */ - inputRewrites[hashPlaceholder(outputName)] = worker.store.printStorePath(scratchPath); - - /* Additional tasks if we know the final path a priori. */ - if (!status.known) continue; - auto fixedFinalPath = status.known->path; - - /* Additional tasks if the final and scratch are both known and - differ. */ - if (fixedFinalPath == scratchPath) continue; - - /* Ensure scratch path is ours to use. */ - deletePath(worker.store.printStorePath(scratchPath)); - - /* Rewrite and unrewrite paths */ - { - std::string h1 { fixedFinalPath.hashPart() }; - std::string h2 { scratchPath.hashPart() }; - inputRewrites[h1] = h2; - } - - redirectedOutputs.insert_or_assign(std::move(fixedFinalPath), std::move(scratchPath)); - } - - /* Construct the environment passed to the builder. */ - initEnv(); - - writeStructuredAttrs(); - - /* Handle exportReferencesGraph(), if set. */ - if (!parsedDrv->getStructuredAttrs()) { - /* The `exportReferencesGraph' feature allows the references graph - to be passed to a builder. This attribute should be a list of - pairs [name1 path1 name2 path2 ...]. The references graph of - each `pathN' will be stored in a text file `nameN' in the - temporary build directory. The text files have the format used - by `nix-store --register-validity'. However, the deriver - fields are left empty. */ - string s = get(drv->env, "exportReferencesGraph").value_or(""); - Strings ss = tokenizeString(s); - if (ss.size() % 2 != 0) - throw BuildError("odd number of tokens in 'exportReferencesGraph': '%1%'", s); - for (Strings::iterator i = ss.begin(); i != ss.end(); ) { - string fileName = *i++; - static std::regex regex("[A-Za-z_][A-Za-z0-9_.-]*"); - if (!std::regex_match(fileName, regex)) - throw Error("invalid file name '%s' in 'exportReferencesGraph'", fileName); - - auto storePathS = *i++; - if (!worker.store.isInStore(storePathS)) - throw BuildError("'exportReferencesGraph' contains a non-store path '%1%'", storePathS); - auto storePath = worker.store.toStorePath(storePathS).first; - - /* Write closure info to . */ - writeFile(tmpDir + "/" + fileName, - worker.store.makeValidityRegistration( - exportReferences({storePath}), false, false)); - } - } - - if (useChroot) { - - /* Allow a user-configurable set of directories from the - host file system. */ - PathSet dirs = settings.sandboxPaths; - PathSet dirs2 = settings.extraSandboxPaths; - dirs.insert(dirs2.begin(), dirs2.end()); - - dirsInChroot.clear(); - - for (auto i : dirs) { - if (i.empty()) continue; - bool optional = false; - if (i[i.size() - 1] == '?') { - optional = true; - i.pop_back(); - } - size_t p = i.find('='); - if (p == string::npos) - dirsInChroot[i] = {i, optional}; - else - dirsInChroot[string(i, 0, p)] = {string(i, p + 1), optional}; - } - dirsInChroot[tmpDirInSandbox] = tmpDir; - - /* Add the closure of store paths to the chroot. */ - StorePathSet closure; - for (auto & i : dirsInChroot) - try { - if (worker.store.isInStore(i.second.source)) - worker.store.computeFSClosure(worker.store.toStorePath(i.second.source).first, closure); - } catch (InvalidPath & e) { - } catch (Error & e) { - e.addTrace({}, "while processing 'sandbox-paths'"); - throw; - } - for (auto & i : closure) { - auto p = worker.store.printStorePath(i); - dirsInChroot.insert_or_assign(p, p); - } - - PathSet allowedPaths = settings.allowedImpureHostPrefixes; - - /* This works like the above, except on a per-derivation level */ - auto impurePaths = parsedDrv->getStringsAttr("__impureHostDeps").value_or(Strings()); - - for (auto & i : impurePaths) { - bool found = false; - /* Note: we're not resolving symlinks here to prevent - giving a non-root user info about inaccessible - files. */ - Path canonI = canonPath(i); - /* If only we had a trie to do this more efficiently :) luckily, these are generally going to be pretty small */ - for (auto & a : allowedPaths) { - Path canonA = canonPath(a); - if (canonI == canonA || isInDir(canonI, canonA)) { - found = true; - break; - } - } - if (!found) - throw Error("derivation '%s' requested impure path '%s', but it was not in allowed-impure-host-deps", - worker.store.printStorePath(drvPath), i); - - dirsInChroot[i] = i; - } - -#if __linux__ - /* Create a temporary directory in which we set up the chroot - environment using bind-mounts. We put it in the Nix store - to ensure that we can create hard-links to non-directory - inputs in the fake Nix store in the chroot (see below). */ - chrootRootDir = worker.store.Store::toRealPath(drvPath) + ".chroot"; - deletePath(chrootRootDir); - - /* Clean up the chroot directory automatically. */ - autoDelChroot = std::make_shared(chrootRootDir); - - printMsg(lvlChatty, format("setting up chroot environment in '%1%'") % chrootRootDir); - - if (mkdir(chrootRootDir.c_str(), 0750) == -1) - throw SysError("cannot create '%1%'", chrootRootDir); - - if (buildUser && chown(chrootRootDir.c_str(), 0, buildUser->getGID()) == -1) - throw SysError("cannot change ownership of '%1%'", chrootRootDir); - - /* Create a writable /tmp in the chroot. Many builders need - this. (Of course they should really respect $TMPDIR - instead.) */ - Path chrootTmpDir = chrootRootDir + "/tmp"; - createDirs(chrootTmpDir); - chmod_(chrootTmpDir, 01777); - - /* Create a /etc/passwd with entries for the build user and the - nobody account. The latter is kind of a hack to support - Samba-in-QEMU. */ - createDirs(chrootRootDir + "/etc"); - - writeFile(chrootRootDir + "/etc/passwd", fmt( - "root:x:0:0:Nix build user:%3%:/noshell\n" - "nixbld:x:%1%:%2%:Nix build user:%3%:/noshell\n" - "nobody:x:65534:65534:Nobody:/:/noshell\n", - sandboxUid(), sandboxGid(), settings.sandboxBuildDir)); - - /* Declare the build user's group so that programs get a consistent - view of the system (e.g., "id -gn"). */ - writeFile(chrootRootDir + "/etc/group", - fmt("root:x:0:\n" - "nixbld:!:%1%:\n" - "nogroup:x:65534:\n", sandboxGid())); - - /* Create /etc/hosts with localhost entry. */ - if (!(derivationIsImpure(derivationType))) - writeFile(chrootRootDir + "/etc/hosts", "127.0.0.1 localhost\n::1 localhost\n"); - - /* Make the closure of the inputs available in the chroot, - rather than the whole Nix store. This prevents any access - to undeclared dependencies. Directories are bind-mounted, - while other inputs are hard-linked (since only directories - can be bind-mounted). !!! As an extra security - precaution, make the fake Nix store only writable by the - build user. */ - Path chrootStoreDir = chrootRootDir + worker.store.storeDir; - createDirs(chrootStoreDir); - chmod_(chrootStoreDir, 01775); - - if (buildUser && chown(chrootStoreDir.c_str(), 0, buildUser->getGID()) == -1) - throw SysError("cannot change ownership of '%1%'", chrootStoreDir); - - for (auto & i : inputPaths) { - auto p = worker.store.printStorePath(i); - Path r = worker.store.toRealPath(p); - if (S_ISDIR(lstat(r).st_mode)) - dirsInChroot.insert_or_assign(p, r); - else - linkOrCopy(r, chrootRootDir + p); - } - - /* If we're repairing, checking or rebuilding part of a - multiple-outputs derivation, it's possible that we're - rebuilding a path that is in settings.dirsInChroot - (typically the dependencies of /bin/sh). Throw them - out. */ - for (auto & i : drv->outputsAndOptPaths(worker.store)) { - /* If the name isn't known a priori (i.e. floating - content-addressed derivation), the temporary location we use - should be fresh. Freshness means it is impossible that the path - is already in the sandbox, so we don't need to worry about - removing it. */ - if (i.second.second) - dirsInChroot.erase(worker.store.printStorePath(*i.second.second)); - } - -#elif __APPLE__ - /* We don't really have any parent prep work to do (yet?) - All work happens in the child, instead. */ -#else - throw Error("sandboxing builds is not supported on this platform"); -#endif - } - - if (needsHashRewrite() && pathExists(homeDir)) - throw Error("home directory '%1%' exists; please remove it to assure purity of builds without sandboxing", homeDir); - - if (useChroot && settings.preBuildHook != "" && dynamic_cast(drv.get())) { - printMsg(lvlChatty, format("executing pre-build hook '%1%'") - % settings.preBuildHook); - auto args = useChroot ? Strings({worker.store.printStorePath(drvPath), chrootRootDir}) : - Strings({ worker.store.printStorePath(drvPath) }); - enum BuildHookState { - stBegin, - stExtraChrootDirs - }; - auto state = stBegin; - auto lines = runProgram(settings.preBuildHook, false, args); - auto lastPos = std::string::size_type{0}; - for (auto nlPos = lines.find('\n'); nlPos != string::npos; - nlPos = lines.find('\n', lastPos)) { - auto line = std::string{lines, lastPos, nlPos - lastPos}; - lastPos = nlPos + 1; - if (state == stBegin) { - if (line == "extra-sandbox-paths" || line == "extra-chroot-dirs") { - state = stExtraChrootDirs; - } else { - throw Error("unknown pre-build hook command '%1%'", line); - } - } else if (state == stExtraChrootDirs) { - if (line == "") { - state = stBegin; - } else { - auto p = line.find('='); - if (p == string::npos) - dirsInChroot[line] = line; - else - dirsInChroot[string(line, 0, p)] = string(line, p + 1); - } - } - } - } - - /* Fire up a Nix daemon to process recursive Nix calls from the - builder. */ - if (parsedDrv->getRequiredSystemFeatures().count("recursive-nix")) - startDaemon(); - - /* Run the builder. */ - printMsg(lvlChatty, "executing builder '%1%'", drv->builder); - - /* Create the log file. */ - Path logFile = openLogFile(); - - /* Create a pipe to get the output of the builder. */ - //builderOut.create(); - - builderOut.readSide = posix_openpt(O_RDWR | O_NOCTTY); - if (!builderOut.readSide) - throw SysError("opening pseudoterminal master"); - - std::string slaveName(ptsname(builderOut.readSide.get())); - - if (buildUser) { - if (chmod(slaveName.c_str(), 0600)) - throw SysError("changing mode of pseudoterminal slave"); - - if (chown(slaveName.c_str(), buildUser->getUID(), 0)) - throw SysError("changing owner of pseudoterminal slave"); - } -#if __APPLE__ - else { - if (grantpt(builderOut.readSide.get())) - throw SysError("granting access to pseudoterminal slave"); - } -#endif - - #if 0 - // Mount the pt in the sandbox so that the "tty" command works. - // FIXME: this doesn't work with the new devpts in the sandbox. - if (useChroot) - dirsInChroot[slaveName] = {slaveName, false}; - #endif - - if (unlockpt(builderOut.readSide.get())) - throw SysError("unlocking pseudoterminal"); - - builderOut.writeSide = open(slaveName.c_str(), O_RDWR | O_NOCTTY); - if (!builderOut.writeSide) - throw SysError("opening pseudoterminal slave"); - - // Put the pt into raw mode to prevent \n -> \r\n translation. - struct termios term; - if (tcgetattr(builderOut.writeSide.get(), &term)) - throw SysError("getting pseudoterminal attributes"); - - cfmakeraw(&term); - - if (tcsetattr(builderOut.writeSide.get(), TCSANOW, &term)) - throw SysError("putting pseudoterminal into raw mode"); - - result.startTime = time(0); - - /* Fork a child to build the package. */ - ProcessOptions options; - -#if __linux__ - if (useChroot) { - /* Set up private namespaces for the build: - - - The PID namespace causes the build to start as PID 1. - Processes outside of the chroot are not visible to those - on the inside, but processes inside the chroot are - visible from the outside (though with different PIDs). - - - The private mount namespace ensures that all the bind - mounts we do will only show up in this process and its - children, and will disappear automatically when we're - done. - - - The private network namespace ensures that the builder - cannot talk to the outside world (or vice versa). It - only has a private loopback interface. (Fixed-output - derivations are not run in a private network namespace - to allow functions like fetchurl to work.) - - - The IPC namespace prevents the builder from communicating - with outside processes using SysV IPC mechanisms (shared - memory, message queues, semaphores). It also ensures - that all IPC objects are destroyed when the builder - exits. - - - The UTS namespace ensures that builders see a hostname of - localhost rather than the actual hostname. - - We use a helper process to do the clone() to work around - clone() being broken in multi-threaded programs due to - at-fork handlers not being run. Note that we use - CLONE_PARENT to ensure that the real builder is parented to - us. - */ - - if (!(derivationIsImpure(derivationType))) - privateNetwork = true; - - userNamespaceSync.create(); - - options.allowVfork = false; - - Path maxUserNamespaces = "/proc/sys/user/max_user_namespaces"; - static bool userNamespacesEnabled = - pathExists(maxUserNamespaces) - && trim(readFile(maxUserNamespaces)) != "0"; - - usingUserNamespace = userNamespacesEnabled; - - Pid helper = startProcess([&]() { - - /* Drop additional groups here because we can't do it - after we've created the new user namespace. FIXME: - this means that if we're not root in the parent - namespace, we can't drop additional groups; they will - be mapped to nogroup in the child namespace. There does - not seem to be a workaround for this. (But who can tell - from reading user_namespaces(7)?) - See also https://lwn.net/Articles/621612/. */ - if (getuid() == 0 && setgroups(0, 0) == -1) - throw SysError("setgroups failed"); - - size_t stackSize = 1 * 1024 * 1024; - char * stack = (char *) mmap(0, stackSize, - PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); - if (stack == MAP_FAILED) throw SysError("allocating stack"); - - int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | CLONE_PARENT | SIGCHLD; - if (privateNetwork) - flags |= CLONE_NEWNET; - if (usingUserNamespace) - flags |= CLONE_NEWUSER; - - pid_t child = clone(childEntry, stack + stackSize, flags, this); - if (child == -1 && errno == EINVAL) { - /* Fallback for Linux < 2.13 where CLONE_NEWPID and - CLONE_PARENT are not allowed together. */ - flags &= ~CLONE_NEWPID; - child = clone(childEntry, stack + stackSize, flags, this); - } - if (usingUserNamespace && child == -1 && (errno == EPERM || errno == EINVAL)) { - /* Some distros patch Linux to not allow unprivileged - * user namespaces. If we get EPERM or EINVAL, try - * without CLONE_NEWUSER and see if that works. - */ - usingUserNamespace = false; - flags &= ~CLONE_NEWUSER; - child = clone(childEntry, stack + stackSize, flags, this); - } - /* Otherwise exit with EPERM so we can handle this in the - parent. This is only done when sandbox-fallback is set - to true (the default). */ - if (child == -1 && (errno == EPERM || errno == EINVAL) && settings.sandboxFallback) - _exit(1); - if (child == -1) throw SysError("cloning builder process"); - - writeFull(builderOut.writeSide.get(), - fmt("%d %d\n", usingUserNamespace, child)); - _exit(0); - }, options); - - int res = helper.wait(); - if (res != 0 && settings.sandboxFallback) { - useChroot = false; - initTmpDir(); - goto fallback; - } else if (res != 0) - throw Error("unable to start build process"); - - userNamespaceSync.readSide = -1; - - /* Close the write side to prevent runChild() from hanging - reading from this. */ - Finally cleanup([&]() { - userNamespaceSync.writeSide = -1; - }); - - pid_t tmp; - auto ss = tokenizeString>(readLine(builderOut.readSide.get())); - assert(ss.size() == 2); - usingUserNamespace = ss[0] == "1"; - if (!string2Int(ss[1], tmp)) abort(); - pid = tmp; - - if (usingUserNamespace) { - /* Set the UID/GID mapping of the builder's user namespace - such that the sandbox user maps to the build user, or to - the calling user (if build users are disabled). */ - uid_t hostUid = buildUser ? buildUser->getUID() : getuid(); - uid_t hostGid = buildUser ? buildUser->getGID() : getgid(); - - writeFile("/proc/" + std::to_string(pid) + "/uid_map", - fmt("%d %d 1", sandboxUid(), hostUid)); - - writeFile("/proc/" + std::to_string(pid) + "/setgroups", "deny"); - - writeFile("/proc/" + std::to_string(pid) + "/gid_map", - fmt("%d %d 1", sandboxGid(), hostGid)); - } else { - debug("note: not using a user namespace"); - if (!buildUser) - throw Error("cannot perform a sandboxed build because user namespaces are not enabled; check /proc/sys/user/max_user_namespaces"); - } - - /* Save the mount namespace of the child. We have to do this - *before* the child does a chroot. */ - sandboxMountNamespace = open(fmt("/proc/%d/ns/mnt", (pid_t) pid).c_str(), O_RDONLY); - if (sandboxMountNamespace.get() == -1) - throw SysError("getting sandbox mount namespace"); - - /* Signal the builder that we've updated its user namespace. */ - writeFull(userNamespaceSync.writeSide.get(), "1"); - - } else -#endif - { - fallback: - options.allowVfork = !buildUser && !drv->isBuiltin(); - pid = startProcess([&]() { - runChild(); - }, options); - } - - /* parent */ - pid.setSeparatePG(true); - builderOut.writeSide = -1; - worker.childStarted(shared_from_this(), {builderOut.readSide.get()}, true, true); - - /* Check if setting up the build environment failed. */ - while (true) { - string msg = readLine(builderOut.readSide.get()); - if (string(msg, 0, 1) == "\2") break; - if (string(msg, 0, 1) == "\1") { - FdSource source(builderOut.readSide.get()); - auto ex = readError(source); - ex.addTrace({}, "while setting up the build environment"); - throw ex; - } - debug("sandbox setup: " + msg); - } -} - - -void DerivationGoal::initTmpDir() { - /* In a sandbox, for determinism, always use the same temporary - directory. */ -#if __linux__ - tmpDirInSandbox = useChroot ? settings.sandboxBuildDir : tmpDir; -#else - tmpDirInSandbox = tmpDir; -#endif - - /* In non-structured mode, add all bindings specified in the - derivation via the environment, except those listed in the - passAsFile attribute. Those are passed as file names pointing - to temporary files containing the contents. Note that - passAsFile is ignored in structure mode because it's not - needed (attributes are not passed through the environment, so - there is no size constraint). */ - if (!parsedDrv->getStructuredAttrs()) { - - StringSet passAsFile = tokenizeString(get(drv->env, "passAsFile").value_or("")); - for (auto & i : drv->env) { - if (passAsFile.find(i.first) == passAsFile.end()) { - env[i.first] = i.second; - } else { - auto hash = hashString(htSHA256, i.first); - string fn = ".attr-" + hash.to_string(Base32, false); - Path p = tmpDir + "/" + fn; - writeFile(p, rewriteStrings(i.second, inputRewrites)); - chownToBuilder(p); - env[i.first + "Path"] = tmpDirInSandbox + "/" + fn; - } - } - - } - - /* For convenience, set an environment pointing to the top build - directory. */ - env["NIX_BUILD_TOP"] = tmpDirInSandbox; - - /* Also set TMPDIR and variants to point to this directory. */ - env["TMPDIR"] = env["TEMPDIR"] = env["TMP"] = env["TEMP"] = tmpDirInSandbox; - - /* Explicitly set PWD to prevent problems with chroot builds. In - particular, dietlibc cannot figure out the cwd because the - inode of the current directory doesn't appear in .. (because - getdents returns the inode of the mount point). */ - env["PWD"] = tmpDirInSandbox; -} - - -void DerivationGoal::initEnv() -{ - env.clear(); - - /* Most shells initialise PATH to some default (/bin:/usr/bin:...) when - PATH is not set. We don't want this, so we fill it in with some dummy - value. */ - env["PATH"] = "/path-not-set"; - - /* Set HOME to a non-existing path to prevent certain programs from using - /etc/passwd (or NIS, or whatever) to locate the home directory (for - example, wget looks for ~/.wgetrc). I.e., these tools use /etc/passwd - if HOME is not set, but they will just assume that the settings file - they are looking for does not exist if HOME is set but points to some - non-existing path. */ - env["HOME"] = homeDir; - - /* Tell the builder where the Nix store is. Usually they - shouldn't care, but this is useful for purity checking (e.g., - the compiler or linker might only want to accept paths to files - in the store or in the build directory). */ - env["NIX_STORE"] = worker.store.storeDir; - - /* The maximum number of cores to utilize for parallel building. */ - env["NIX_BUILD_CORES"] = (format("%d") % settings.buildCores).str(); - - initTmpDir(); - - /* Compatibility hack with Nix <= 0.7: if this is a fixed-output - derivation, tell the builder, so that for instance `fetchurl' - can skip checking the output. On older Nixes, this environment - variable won't be set, so `fetchurl' will do the check. */ - if (derivationIsFixed(derivationType)) env["NIX_OUTPUT_CHECKED"] = "1"; - - /* *Only* if this is a fixed-output derivation, propagate the - values of the environment variables specified in the - `impureEnvVars' attribute to the builder. This allows for - instance environment variables for proxy configuration such as - `http_proxy' to be easily passed to downloaders like - `fetchurl'. Passing such environment variables from the caller - to the builder is generally impure, but the output of - fixed-output derivations is by definition pure (since we - already know the cryptographic hash of the output). */ - if (derivationIsImpure(derivationType)) { - for (auto & i : parsedDrv->getStringsAttr("impureEnvVars").value_or(Strings())) - env[i] = getEnv(i).value_or(""); - } - - /* Currently structured log messages piggyback on stderr, but we - may change that in the future. So tell the builder which file - descriptor to use for that. */ - env["NIX_LOG_FD"] = "2"; - - /* Trigger colored output in various tools. */ - env["TERM"] = "xterm-256color"; -} - - -static std::regex shVarName("[A-Za-z_][A-Za-z0-9_]*"); - - -void DerivationGoal::writeStructuredAttrs() -{ - auto structuredAttrs = parsedDrv->getStructuredAttrs(); - if (!structuredAttrs) return; - - auto json = *structuredAttrs; - - /* Add an "outputs" object containing the output paths. */ - nlohmann::json outputs; - for (auto & i : drv->outputs) { - /* The placeholder must have a rewrite, so we use it to cover both the - cases where we know or don't know the output path ahead of time. */ - outputs[i.first] = rewriteStrings(hashPlaceholder(i.first), inputRewrites); - } - json["outputs"] = outputs; - - /* Handle exportReferencesGraph. */ - auto e = json.find("exportReferencesGraph"); - if (e != json.end() && e->is_object()) { - for (auto i = e->begin(); i != e->end(); ++i) { - std::ostringstream str; - { - JSONPlaceholder jsonRoot(str, true); - StorePathSet storePaths; - for (auto & p : *i) - storePaths.insert(worker.store.parseStorePath(p.get())); - worker.store.pathInfoToJSON(jsonRoot, - exportReferences(storePaths), false, true); - } - json[i.key()] = nlohmann::json::parse(str.str()); // urgh - } - } - - writeFile(tmpDir + "/.attrs.json", rewriteStrings(json.dump(), inputRewrites)); - chownToBuilder(tmpDir + "/.attrs.json"); - - /* As a convenience to bash scripts, write a shell file that - maps all attributes that are representable in bash - - namely, strings, integers, nulls, Booleans, and arrays and - objects consisting entirely of those values. (So nested - arrays or objects are not supported.) */ - - auto handleSimpleType = [](const nlohmann::json & value) -> std::optional { - if (value.is_string()) - return shellEscape(value); - - if (value.is_number()) { - auto f = value.get(); - if (std::ceil(f) == f) - return std::to_string(value.get()); - } - - if (value.is_null()) - return std::string("''"); - - if (value.is_boolean()) - return value.get() ? std::string("1") : std::string(""); - - return {}; - }; - - std::string jsonSh; - - for (auto i = json.begin(); i != json.end(); ++i) { - - if (!std::regex_match(i.key(), shVarName)) continue; - - auto & value = i.value(); - - auto s = handleSimpleType(value); - if (s) - jsonSh += fmt("declare %s=%s\n", i.key(), *s); - - else if (value.is_array()) { - std::string s2; - bool good = true; - - for (auto i = value.begin(); i != value.end(); ++i) { - auto s3 = handleSimpleType(i.value()); - if (!s3) { good = false; break; } - s2 += *s3; s2 += ' '; - } - - if (good) - jsonSh += fmt("declare -a %s=(%s)\n", i.key(), s2); - } - - else if (value.is_object()) { - std::string s2; - bool good = true; - - for (auto i = value.begin(); i != value.end(); ++i) { - auto s3 = handleSimpleType(i.value()); - if (!s3) { good = false; break; } - s2 += fmt("[%s]=%s ", shellEscape(i.key()), *s3); - } - - if (good) - jsonSh += fmt("declare -A %s=(%s)\n", i.key(), s2); - } - } - - writeFile(tmpDir + "/.attrs.sh", rewriteStrings(jsonSh, inputRewrites)); - chownToBuilder(tmpDir + "/.attrs.sh"); -} - -struct RestrictedStoreConfig : LocalFSStoreConfig -{ - using LocalFSStoreConfig::LocalFSStoreConfig; - const std::string name() { return "Restricted Store"; } -}; - -/* A wrapper around LocalStore that only allows building/querying of - paths that are in the input closures of the build or were added via - recursive Nix calls. */ -struct RestrictedStore : public LocalFSStore, public virtual RestrictedStoreConfig -{ - ref next; - - DerivationGoal & goal; - - RestrictedStore(const Params & params, ref next, DerivationGoal & goal) - : StoreConfig(params), Store(params), LocalFSStore(params), next(next), goal(goal) - { } - - Path getRealStoreDir() override - { return next->realStoreDir; } - - std::string getUri() override - { return next->getUri(); } - - StorePathSet queryAllValidPaths() override - { - StorePathSet paths; - for (auto & p : goal.inputPaths) paths.insert(p); - for (auto & p : goal.addedPaths) paths.insert(p); - return paths; - } - - void queryPathInfoUncached(const StorePath & path, - Callback> callback) noexcept override - { - if (goal.isAllowed(path)) { - try { - /* Censor impure information. */ - auto info = std::make_shared(*next->queryPathInfo(path)); - info->deriver.reset(); - info->registrationTime = 0; - info->ultimate = false; - info->sigs.clear(); - callback(info); - } catch (InvalidPath &) { - callback(nullptr); - } - } else - callback(nullptr); - }; - - void queryReferrers(const StorePath & path, StorePathSet & referrers) override - { } - - std::map> queryPartialDerivationOutputMap(const StorePath & path) override - { - if (!goal.isAllowed(path)) - throw InvalidPath("cannot query output map for unknown path '%s' in recursive Nix", printStorePath(path)); - return next->queryPartialDerivationOutputMap(path); - } - - std::optional queryPathFromHashPart(const std::string & hashPart) override - { throw Error("queryPathFromHashPart"); } - - StorePath addToStore(const string & name, const Path & srcPath, - FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, - PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) override - { throw Error("addToStore"); } - - void addToStore(const ValidPathInfo & info, Source & narSource, - RepairFlag repair = NoRepair, CheckSigsFlag checkSigs = CheckSigs) override - { - next->addToStore(info, narSource, repair, checkSigs); - goal.addDependency(info.path); - } - - StorePath addTextToStore(const string & name, const string & s, - const StorePathSet & references, RepairFlag repair = NoRepair) override - { - auto path = next->addTextToStore(name, s, references, repair); - goal.addDependency(path); - return path; - } - - void narFromPath(const StorePath & path, Sink & sink) override - { - if (!goal.isAllowed(path)) - throw InvalidPath("cannot dump unknown path '%s' in recursive Nix", printStorePath(path)); - LocalFSStore::narFromPath(path, sink); - } - - void ensurePath(const StorePath & path) override - { - if (!goal.isAllowed(path)) - throw InvalidPath("cannot substitute unknown path '%s' in recursive Nix", printStorePath(path)); - /* Nothing to be done; 'path' must already be valid. */ - } - - void buildPaths(const std::vector & paths, BuildMode buildMode) override - { - if (buildMode != bmNormal) throw Error("unsupported build mode"); - - StorePathSet newPaths; - - for (auto & path : paths) { - if (!goal.isAllowed(path.path)) - throw InvalidPath("cannot build unknown path '%s' in recursive Nix", printStorePath(path.path)); - } - - next->buildPaths(paths, buildMode); - - for (auto & path : paths) { - if (!path.path.isDerivation()) continue; - auto outputs = next->queryDerivationOutputMap(path.path); - for (auto & output : outputs) - if (wantOutput(output.first, path.outputs)) - newPaths.insert(output.second); - } - - StorePathSet closure; - next->computeFSClosure(newPaths, closure); - for (auto & path : closure) - goal.addDependency(path); - } - - BuildResult buildDerivation(const StorePath & drvPath, const BasicDerivation & drv, - BuildMode buildMode = bmNormal) override - { unsupported("buildDerivation"); } - - void addTempRoot(const StorePath & path) override - { } - - void addIndirectRoot(const Path & path) override - { } - - Roots findRoots(bool censor) override - { return Roots(); } - - void collectGarbage(const GCOptions & options, GCResults & results) override - { } - - void addSignatures(const StorePath & storePath, const StringSet & sigs) override - { unsupported("addSignatures"); } - - void queryMissing(const std::vector & targets, - StorePathSet & willBuild, StorePathSet & willSubstitute, StorePathSet & unknown, - uint64_t & downloadSize, uint64_t & narSize) override - { - /* This is slightly impure since it leaks information to the - client about what paths will be built/substituted or are - already present. Probably not a big deal. */ - - std::vector allowed; - for (auto & path : targets) { - if (goal.isAllowed(path.path)) - allowed.emplace_back(path); - else - unknown.insert(path.path); - } - - next->queryMissing(allowed, willBuild, willSubstitute, - unknown, downloadSize, narSize); - } -}; - - -void DerivationGoal::startDaemon() -{ - settings.requireExperimentalFeature("recursive-nix"); - - Store::Params params; - params["path-info-cache-size"] = "0"; - params["store"] = worker.store.storeDir; - params["root"] = worker.store.rootDir; - params["state"] = "/no-such-path"; - params["log"] = "/no-such-path"; - auto store = make_ref(params, - ref(std::dynamic_pointer_cast(worker.store.shared_from_this())), - *this); - - addedPaths.clear(); - - auto socketName = ".nix-socket"; - Path socketPath = tmpDir + "/" + socketName; - env["NIX_REMOTE"] = "unix://" + tmpDirInSandbox + "/" + socketName; - - daemonSocket = createUnixDomainSocket(socketPath, 0600); - - chownToBuilder(socketPath); - - daemonThread = std::thread([this, store]() { - - while (true) { - - /* Accept a connection. */ - struct sockaddr_un remoteAddr; - socklen_t remoteAddrLen = sizeof(remoteAddr); - - AutoCloseFD remote = accept(daemonSocket.get(), - (struct sockaddr *) &remoteAddr, &remoteAddrLen); - if (!remote) { - if (errno == EINTR) continue; - if (errno == EINVAL) break; - throw SysError("accepting connection"); - } - - closeOnExec(remote.get()); - - debug("received daemon connection"); - - auto workerThread = std::thread([store, remote{std::move(remote)}]() { - FdSource from(remote.get()); - FdSink to(remote.get()); - try { - daemon::processConnection(store, from, to, - daemon::NotTrusted, daemon::Recursive, - [&](Store & store) { store.createUser("nobody", 65535); }); - debug("terminated daemon connection"); - } catch (SysError &) { - ignoreException(); - } - }); - - daemonWorkerThreads.push_back(std::move(workerThread)); - } - - debug("daemon shutting down"); - }); -} - - -void DerivationGoal::stopDaemon() -{ - if (daemonSocket && shutdown(daemonSocket.get(), SHUT_RDWR) == -1) - throw SysError("shutting down daemon socket"); - - if (daemonThread.joinable()) - daemonThread.join(); - - // FIXME: should prune worker threads more quickly. - // FIXME: shutdown the client socket to speed up worker termination. - for (auto & thread : daemonWorkerThreads) - thread.join(); - daemonWorkerThreads.clear(); - - daemonSocket = -1; -} - - -void DerivationGoal::addDependency(const StorePath & path) -{ - if (isAllowed(path)) return; - - addedPaths.insert(path); - - /* If we're doing a sandbox build, then we have to make the path - appear in the sandbox. */ - if (useChroot) { - - debug("materialising '%s' in the sandbox", worker.store.printStorePath(path)); - - #if __linux__ - - Path source = worker.store.Store::toRealPath(path); - Path target = chrootRootDir + worker.store.printStorePath(path); - debug("bind-mounting %s -> %s", target, source); - - if (pathExists(target)) - throw Error("store path '%s' already exists in the sandbox", worker.store.printStorePath(path)); - - auto st = lstat(source); - - if (S_ISDIR(st.st_mode)) { - - /* Bind-mount the path into the sandbox. This requires - entering its mount namespace, which is not possible - in multithreaded programs. So we do this in a - child process.*/ - Pid child(startProcess([&]() { - - if (setns(sandboxMountNamespace.get(), 0) == -1) - throw SysError("entering sandbox mount namespace"); - - createDirs(target); - - if (mount(source.c_str(), target.c_str(), "", MS_BIND, 0) == -1) - throw SysError("bind mount from '%s' to '%s' failed", source, target); - - _exit(0); - })); - - int status = child.wait(); - if (status != 0) - throw Error("could not add path '%s' to sandbox", worker.store.printStorePath(path)); - - } else - linkOrCopy(source, target); - - #else - throw Error("don't know how to make path '%s' (produced by a recursive Nix call) appear in the sandbox", - worker.store.printStorePath(path)); - #endif - - } -} - - -void DerivationGoal::chownToBuilder(const Path & path) -{ - if (!buildUser) return; - if (chown(path.c_str(), buildUser->getUID(), buildUser->getGID()) == -1) - throw SysError("cannot change ownership of '%1%'", path); -} - - -void setupSeccomp() -{ -#if __linux__ - if (!settings.filterSyscalls) return; -#if HAVE_SECCOMP - scmp_filter_ctx ctx; - - if (!(ctx = seccomp_init(SCMP_ACT_ALLOW))) - throw SysError("unable to initialize seccomp mode 2"); - - Finally cleanup([&]() { - seccomp_release(ctx); - }); - - if (nativeSystem == "x86_64-linux" && - seccomp_arch_add(ctx, SCMP_ARCH_X86) != 0) - throw SysError("unable to add 32-bit seccomp architecture"); - - if (nativeSystem == "x86_64-linux" && - seccomp_arch_add(ctx, SCMP_ARCH_X32) != 0) - throw SysError("unable to add X32 seccomp architecture"); - - if (nativeSystem == "aarch64-linux" && - seccomp_arch_add(ctx, SCMP_ARCH_ARM) != 0) - printError("unable to add ARM seccomp architecture; this may result in spurious build failures if running 32-bit ARM processes"); - - /* Prevent builders from creating setuid/setgid binaries. */ - for (int perm : { S_ISUID, S_ISGID }) { - if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(chmod), 1, - SCMP_A1(SCMP_CMP_MASKED_EQ, (scmp_datum_t) perm, (scmp_datum_t) perm)) != 0) - throw SysError("unable to add seccomp rule"); - - if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(fchmod), 1, - SCMP_A1(SCMP_CMP_MASKED_EQ, (scmp_datum_t) perm, (scmp_datum_t) perm)) != 0) - throw SysError("unable to add seccomp rule"); - - if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(fchmodat), 1, - SCMP_A2(SCMP_CMP_MASKED_EQ, (scmp_datum_t) perm, (scmp_datum_t) perm)) != 0) - throw SysError("unable to add seccomp rule"); - } - - /* Prevent builders from creating EAs or ACLs. Not all filesystems - support these, and they're not allowed in the Nix store because - they're not representable in the NAR serialisation. */ - if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(setxattr), 0) != 0 || - seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(lsetxattr), 0) != 0 || - seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(fsetxattr), 0) != 0) - throw SysError("unable to add seccomp rule"); - - if (seccomp_attr_set(ctx, SCMP_FLTATR_CTL_NNP, settings.allowNewPrivileges ? 0 : 1) != 0) - throw SysError("unable to set 'no new privileges' seccomp attribute"); - - if (seccomp_load(ctx) != 0) - throw SysError("unable to load seccomp BPF program"); -#else - throw Error( - "seccomp is not supported on this platform; " - "you can bypass this error by setting the option 'filter-syscalls' to false, but note that untrusted builds can then create setuid binaries!"); -#endif -#endif -} - - -void DerivationGoal::runChild() -{ - /* Warning: in the child we should absolutely not make any SQLite - calls! */ - - try { /* child */ - - commonChildInit(builderOut); - - try { - setupSeccomp(); - } catch (...) { - if (buildUser) throw; - } - - bool setUser = true; - - /* Make the contents of netrc available to builtin:fetchurl - (which may run under a different uid and/or in a sandbox). */ - std::string netrcData; - try { - if (drv->isBuiltin() && drv->builder == "builtin:fetchurl") - netrcData = readFile(settings.netrcFile); - } catch (SysError &) { } - -#if __linux__ - if (useChroot) { - - userNamespaceSync.writeSide = -1; - - if (drainFD(userNamespaceSync.readSide.get()) != "1") - throw Error("user namespace initialisation failed"); - - userNamespaceSync.readSide = -1; - - if (privateNetwork) { - - /* Initialise the loopback interface. */ - AutoCloseFD fd(socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)); - if (!fd) throw SysError("cannot open IP socket"); - - struct ifreq ifr; - strcpy(ifr.ifr_name, "lo"); - ifr.ifr_flags = IFF_UP | IFF_LOOPBACK | IFF_RUNNING; - if (ioctl(fd.get(), SIOCSIFFLAGS, &ifr) == -1) - throw SysError("cannot set loopback interface flags"); - } - - /* Set the hostname etc. to fixed values. */ - char hostname[] = "localhost"; - if (sethostname(hostname, sizeof(hostname)) == -1) - throw SysError("cannot set host name"); - char domainname[] = "(none)"; // kernel default - if (setdomainname(domainname, sizeof(domainname)) == -1) - throw SysError("cannot set domain name"); - - /* Make all filesystems private. This is necessary - because subtrees may have been mounted as "shared" - (MS_SHARED). (Systemd does this, for instance.) Even - though we have a private mount namespace, mounting - filesystems on top of a shared subtree still propagates - outside of the namespace. Making a subtree private is - local to the namespace, though, so setting MS_PRIVATE - does not affect the outside world. */ - if (mount(0, "/", 0, MS_PRIVATE | MS_REC, 0) == -1) - throw SysError("unable to make '/' private"); - - /* Bind-mount chroot directory to itself, to treat it as a - different filesystem from /, as needed for pivot_root. */ - if (mount(chrootRootDir.c_str(), chrootRootDir.c_str(), 0, MS_BIND, 0) == -1) - throw SysError("unable to bind mount '%1%'", chrootRootDir); - - /* Bind-mount the sandbox's Nix store onto itself so that - we can mark it as a "shared" subtree, allowing bind - mounts made in *this* mount namespace to be propagated - into the child namespace created by the - unshare(CLONE_NEWNS) call below. - - Marking chrootRootDir as MS_SHARED causes pivot_root() - to fail with EINVAL. Don't know why. */ - Path chrootStoreDir = chrootRootDir + worker.store.storeDir; - - if (mount(chrootStoreDir.c_str(), chrootStoreDir.c_str(), 0, MS_BIND, 0) == -1) - throw SysError("unable to bind mount the Nix store", chrootStoreDir); - - if (mount(0, chrootStoreDir.c_str(), 0, MS_SHARED, 0) == -1) - throw SysError("unable to make '%s' shared", chrootStoreDir); - - /* Set up a nearly empty /dev, unless the user asked to - bind-mount the host /dev. */ - Strings ss; - if (dirsInChroot.find("/dev") == dirsInChroot.end()) { - createDirs(chrootRootDir + "/dev/shm"); - createDirs(chrootRootDir + "/dev/pts"); - ss.push_back("/dev/full"); - if (worker.store.systemFeatures.get().count("kvm") && pathExists("/dev/kvm")) - ss.push_back("/dev/kvm"); - ss.push_back("/dev/null"); - ss.push_back("/dev/random"); - ss.push_back("/dev/tty"); - ss.push_back("/dev/urandom"); - ss.push_back("/dev/zero"); - createSymlink("/proc/self/fd", chrootRootDir + "/dev/fd"); - createSymlink("/proc/self/fd/0", chrootRootDir + "/dev/stdin"); - createSymlink("/proc/self/fd/1", chrootRootDir + "/dev/stdout"); - createSymlink("/proc/self/fd/2", chrootRootDir + "/dev/stderr"); - } - - /* Fixed-output derivations typically need to access the - network, so give them access to /etc/resolv.conf and so - on. */ - if (derivationIsImpure(derivationType)) { - ss.push_back("/etc/resolv.conf"); - - // Only use nss functions to resolve hosts and - // services. Don’t use it for anything else that may - // be configured for this system. This limits the - // potential impurities introduced in fixed-outputs. - writeFile(chrootRootDir + "/etc/nsswitch.conf", "hosts: files dns\nservices: files\n"); - - ss.push_back("/etc/services"); - ss.push_back("/etc/hosts"); - if (pathExists("/var/run/nscd/socket")) - ss.push_back("/var/run/nscd/socket"); - } - - for (auto & i : ss) dirsInChroot.emplace(i, i); - - /* Bind-mount all the directories from the "host" - filesystem that we want in the chroot - environment. */ - auto doBind = [&](const Path & source, const Path & target, bool optional = false) { - debug("bind mounting '%1%' to '%2%'", source, target); - struct stat st; - if (stat(source.c_str(), &st) == -1) { - if (optional && errno == ENOENT) - return; - else - throw SysError("getting attributes of path '%1%'", source); - } - if (S_ISDIR(st.st_mode)) - createDirs(target); - else { - createDirs(dirOf(target)); - writeFile(target, ""); - } - if (mount(source.c_str(), target.c_str(), "", MS_BIND | MS_REC, 0) == -1) - throw SysError("bind mount from '%1%' to '%2%' failed", source, target); - }; - - for (auto & i : dirsInChroot) { - if (i.second.source == "/proc") continue; // backwards compatibility - doBind(i.second.source, chrootRootDir + i.first, i.second.optional); - } - - /* Bind a new instance of procfs on /proc. */ - createDirs(chrootRootDir + "/proc"); - if (mount("none", (chrootRootDir + "/proc").c_str(), "proc", 0, 0) == -1) - throw SysError("mounting /proc"); - - /* Mount a new tmpfs on /dev/shm to ensure that whatever - the builder puts in /dev/shm is cleaned up automatically. */ - if (pathExists("/dev/shm") && mount("none", (chrootRootDir + "/dev/shm").c_str(), "tmpfs", 0, - fmt("size=%s", settings.sandboxShmSize).c_str()) == -1) - throw SysError("mounting /dev/shm"); - - /* Mount a new devpts on /dev/pts. Note that this - requires the kernel to be compiled with - CONFIG_DEVPTS_MULTIPLE_INSTANCES=y (which is the case - if /dev/ptx/ptmx exists). */ - if (pathExists("/dev/pts/ptmx") && - !pathExists(chrootRootDir + "/dev/ptmx") - && !dirsInChroot.count("/dev/pts")) - { - if (mount("none", (chrootRootDir + "/dev/pts").c_str(), "devpts", 0, "newinstance,mode=0620") == 0) - { - createSymlink("/dev/pts/ptmx", chrootRootDir + "/dev/ptmx"); - - /* Make sure /dev/pts/ptmx is world-writable. With some - Linux versions, it is created with permissions 0. */ - chmod_(chrootRootDir + "/dev/pts/ptmx", 0666); - } else { - if (errno != EINVAL) - throw SysError("mounting /dev/pts"); - doBind("/dev/pts", chrootRootDir + "/dev/pts"); - doBind("/dev/ptmx", chrootRootDir + "/dev/ptmx"); - } - } - - /* Unshare this mount namespace. This is necessary because - pivot_root() below changes the root of the mount - namespace. This means that the call to setns() in - addDependency() would hide the host's filesystem, - making it impossible to bind-mount paths from the host - Nix store into the sandbox. Therefore, we save the - pre-pivot_root namespace in - sandboxMountNamespace. Since we made /nix/store a - shared subtree above, this allows addDependency() to - make paths appear in the sandbox. */ - if (unshare(CLONE_NEWNS) == -1) - throw SysError("unsharing mount namespace"); - - /* Do the chroot(). */ - if (chdir(chrootRootDir.c_str()) == -1) - throw SysError("cannot change directory to '%1%'", chrootRootDir); - - if (mkdir("real-root", 0) == -1) - throw SysError("cannot create real-root directory"); - - if (pivot_root(".", "real-root") == -1) - throw SysError("cannot pivot old root directory onto '%1%'", (chrootRootDir + "/real-root")); - - if (chroot(".") == -1) - throw SysError("cannot change root directory to '%1%'", chrootRootDir); - - if (umount2("real-root", MNT_DETACH) == -1) - throw SysError("cannot unmount real root filesystem"); - - if (rmdir("real-root") == -1) - throw SysError("cannot remove real-root directory"); - - /* Switch to the sandbox uid/gid in the user namespace, - which corresponds to the build user or calling user in - the parent namespace. */ - if (setgid(sandboxGid()) == -1) - throw SysError("setgid failed"); - if (setuid(sandboxUid()) == -1) - throw SysError("setuid failed"); - - setUser = false; - } -#endif - - if (chdir(tmpDirInSandbox.c_str()) == -1) - throw SysError("changing into '%1%'", tmpDir); - - /* Close all other file descriptors. */ - closeMostFDs({STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO}); - -#if __linux__ - /* Change the personality to 32-bit if we're doing an - i686-linux build on an x86_64-linux machine. */ - struct utsname utsbuf; - uname(&utsbuf); - if (drv->platform == "i686-linux" && - (settings.thisSystem == "x86_64-linux" || - (!strcmp(utsbuf.sysname, "Linux") && !strcmp(utsbuf.machine, "x86_64")))) { - if (personality(PER_LINUX32) == -1) - throw SysError("cannot set i686-linux personality"); - } - - /* Impersonate a Linux 2.6 machine to get some determinism in - builds that depend on the kernel version. */ - if ((drv->platform == "i686-linux" || drv->platform == "x86_64-linux") && settings.impersonateLinux26) { - int cur = personality(0xffffffff); - if (cur != -1) personality(cur | 0x0020000 /* == UNAME26 */); - } - - /* Disable address space randomization for improved - determinism. */ - int cur = personality(0xffffffff); - if (cur != -1) personality(cur | ADDR_NO_RANDOMIZE); -#endif - - /* Disable core dumps by default. */ - struct rlimit limit = { 0, RLIM_INFINITY }; - setrlimit(RLIMIT_CORE, &limit); - - // FIXME: set other limits to deterministic values? - - /* Fill in the environment. */ - Strings envStrs; - for (auto & i : env) - envStrs.push_back(rewriteStrings(i.first + "=" + i.second, inputRewrites)); - - /* If we are running in `build-users' mode, then switch to the - user we allocated above. Make sure that we drop all root - privileges. Note that above we have closed all file - descriptors except std*, so that's safe. Also note that - setuid() when run as root sets the real, effective and - saved UIDs. */ - if (setUser && buildUser) { - /* Preserve supplementary groups of the build user, to allow - admins to specify groups such as "kvm". */ - if (!buildUser->getSupplementaryGIDs().empty() && - setgroups(buildUser->getSupplementaryGIDs().size(), - buildUser->getSupplementaryGIDs().data()) == -1) - throw SysError("cannot set supplementary groups of build user"); - - if (setgid(buildUser->getGID()) == -1 || - getgid() != buildUser->getGID() || - getegid() != buildUser->getGID()) - throw SysError("setgid failed"); - - if (setuid(buildUser->getUID()) == -1 || - getuid() != buildUser->getUID() || - geteuid() != buildUser->getUID()) - throw SysError("setuid failed"); - } - - /* Fill in the arguments. */ - Strings args; - - const char *builder = "invalid"; - - if (drv->isBuiltin()) { - ; - } -#if __APPLE__ - else { - /* This has to appear before import statements. */ - std::string sandboxProfile = "(version 1)\n"; - - if (useChroot) { - - /* Lots and lots and lots of file functions freak out if they can't stat their full ancestry */ - PathSet ancestry; - - /* We build the ancestry before adding all inputPaths to the store because we know they'll - all have the same parents (the store), and there might be lots of inputs. This isn't - particularly efficient... I doubt it'll be a bottleneck in practice */ - for (auto & i : dirsInChroot) { - Path cur = i.first; - while (cur.compare("/") != 0) { - cur = dirOf(cur); - ancestry.insert(cur); - } - } - - /* And we want the store in there regardless of how empty dirsInChroot. We include the innermost - path component this time, since it's typically /nix/store and we care about that. */ - Path cur = worker.store.storeDir; - while (cur.compare("/") != 0) { - ancestry.insert(cur); - cur = dirOf(cur); - } - - /* Add all our input paths to the chroot */ - for (auto & i : inputPaths) { - auto p = worker.store.printStorePath(i); - dirsInChroot[p] = p; - } - - /* Violations will go to the syslog if you set this. Unfortunately the destination does not appear to be configurable */ - if (settings.darwinLogSandboxViolations) { - sandboxProfile += "(deny default)\n"; - } else { - sandboxProfile += "(deny default (with no-log))\n"; - } - - sandboxProfile += "(import \"sandbox-defaults.sb\")\n"; - - if (derivationIsImpure(derivationType)) - sandboxProfile += "(import \"sandbox-network.sb\")\n"; - - /* Add the output paths we'll use at build-time to the chroot */ - sandboxProfile += "(allow file-read* file-write* process-exec\n"; - for (auto & [_, path] : scratchOutputs) - sandboxProfile += fmt("\t(subpath \"%s\")\n", worker.store.printStorePath(path)); - - sandboxProfile += ")\n"; - - /* Our inputs (transitive dependencies and any impurities computed above) - - without file-write* allowed, access() incorrectly returns EPERM - */ - sandboxProfile += "(allow file-read* file-write* process-exec\n"; - for (auto & i : dirsInChroot) { - if (i.first != i.second.source) - throw Error( - "can't map '%1%' to '%2%': mismatched impure paths not supported on Darwin", - i.first, i.second.source); - - string path = i.first; - struct stat st; - if (lstat(path.c_str(), &st)) { - if (i.second.optional && errno == ENOENT) - continue; - throw SysError("getting attributes of path '%s", path); - } - if (S_ISDIR(st.st_mode)) - sandboxProfile += fmt("\t(subpath \"%s\")\n", path); - else - sandboxProfile += fmt("\t(literal \"%s\")\n", path); - } - sandboxProfile += ")\n"; - - /* Allow file-read* on full directory hierarchy to self. Allows realpath() */ - sandboxProfile += "(allow file-read*\n"; - for (auto & i : ancestry) { - sandboxProfile += fmt("\t(literal \"%s\")\n", i); - } - sandboxProfile += ")\n"; - - sandboxProfile += additionalSandboxProfile; - } else - sandboxProfile += "(import \"sandbox-minimal.sb\")\n"; - - debug("Generated sandbox profile:"); - debug(sandboxProfile); - - Path sandboxFile = tmpDir + "/.sandbox.sb"; - - writeFile(sandboxFile, sandboxProfile); - - bool allowLocalNetworking = parsedDrv->getBoolAttr("__darwinAllowLocalNetworking"); - - /* The tmpDir in scope points at the temporary build directory for our derivation. Some packages try different mechanisms - to find temporary directories, so we want to open up a broader place for them to dump their files, if needed. */ - Path globalTmpDir = canonPath(getEnv("TMPDIR").value_or("/tmp"), true); - - /* They don't like trailing slashes on subpath directives */ - if (globalTmpDir.back() == '/') globalTmpDir.pop_back(); - - if (getEnv("_NIX_TEST_NO_SANDBOX") != "1") { - builder = "/usr/bin/sandbox-exec"; - args.push_back("sandbox-exec"); - args.push_back("-f"); - args.push_back(sandboxFile); - args.push_back("-D"); - args.push_back("_GLOBAL_TMP_DIR=" + globalTmpDir); - args.push_back("-D"); - args.push_back("IMPORT_DIR=" + settings.nixDataDir + "/nix/sandbox/"); - if (allowLocalNetworking) { - args.push_back("-D"); - args.push_back(string("_ALLOW_LOCAL_NETWORKING=1")); - } - args.push_back(drv->builder); - } else { - builder = drv->builder.c_str(); - args.push_back(std::string(baseNameOf(drv->builder))); - } - } -#else - else { - builder = drv->builder.c_str(); - args.push_back(std::string(baseNameOf(drv->builder))); - } -#endif - - for (auto & i : drv->args) - args.push_back(rewriteStrings(i, inputRewrites)); - - /* Indicate that we managed to set up the build environment. */ - writeFull(STDERR_FILENO, string("\2\n")); - - /* Execute the program. This should not return. */ - if (drv->isBuiltin()) { - try { - logger = makeJSONLogger(*logger); - - BasicDerivation & drv2(*drv); - for (auto & e : drv2.env) - e.second = rewriteStrings(e.second, inputRewrites); - - if (drv->builder == "builtin:fetchurl") - builtinFetchurl(drv2, netrcData); - else if (drv->builder == "builtin:buildenv") - builtinBuildenv(drv2); - else if (drv->builder == "builtin:unpack-channel") - builtinUnpackChannel(drv2); - else - throw Error("unsupported builtin function '%1%'", string(drv->builder, 8)); - _exit(0); - } catch (std::exception & e) { - writeFull(STDERR_FILENO, e.what() + std::string("\n")); - _exit(1); - } - } - - execve(builder, stringsToCharPtrs(args).data(), stringsToCharPtrs(envStrs).data()); - - throw SysError("executing '%1%'", drv->builder); - - } catch (Error & e) { - writeFull(STDERR_FILENO, "\1\n"); - FdSink sink(STDERR_FILENO); - sink << e; - sink.flush(); - _exit(1); - } -} - - -void DerivationGoal::registerOutputs() -{ - /* When using a build hook, the build hook can register the output - as valid (by doing `nix-store --import'). If so we don't have - to do anything here. - - We can only early return when the outputs are known a priori. For - floating content-addressed derivations this isn't the case. - */ - if (hook) { - bool allValid = true; - for (auto & i : drv->outputsAndOptPaths(worker.store)) { - if (!i.second.second || !worker.store.isValidPath(*i.second.second)) - allValid = false; - } - if (allValid) return; - } - - std::map infos; - - /* Set of inodes seen during calls to canonicalisePathMetaData() - for this build's outputs. This needs to be shared between - outputs to allow hard links between outputs. */ - InodesSeen inodesSeen; - - Path checkSuffix = ".check"; - bool keepPreviousRound = settings.keepFailed || settings.runDiffHook; - - std::exception_ptr delayedException; - - /* The paths that can be referenced are the input closures, the - output paths, and any paths that have been built via recursive - Nix calls. */ - StorePathSet referenceablePaths; - for (auto & p : inputPaths) referenceablePaths.insert(p); - for (auto & i : scratchOutputs) referenceablePaths.insert(i.second); - for (auto & p : addedPaths) referenceablePaths.insert(p); - - /* FIXME `needsHashRewrite` should probably be removed and we get to the - real reason why we aren't using the chroot dir */ - auto toRealPathChroot = [&](const Path & p) -> Path { - return useChroot && !needsHashRewrite() - ? chrootRootDir + p - : worker.store.toRealPath(p); - }; - - /* Check whether the output paths were created, and make all - output paths read-only. Then get the references of each output (that we - might need to register), so we can topologically sort them. For the ones - that are most definitely already installed, we just store their final - name so we can also use it in rewrites. */ - StringSet outputsToSort; - struct AlreadyRegistered { StorePath path; }; - struct PerhapsNeedToRegister { StorePathSet refs; }; - std::map> outputReferencesIfUnregistered; - std::map outputStats; - for (auto & [outputName, _] : drv->outputs) { - auto actualPath = toRealPathChroot(worker.store.printStorePath(scratchOutputs.at(outputName))); - - outputsToSort.insert(outputName); - - /* Updated wanted info to remove the outputs we definitely don't need to register */ - auto & initialInfo = initialOutputs.at(outputName); - - /* Don't register if already valid, and not checking */ - initialInfo.wanted = buildMode == bmCheck - || !(initialInfo.known && initialInfo.known->isValid()); - if (!initialInfo.wanted) { - outputReferencesIfUnregistered.insert_or_assign( - outputName, - AlreadyRegistered { .path = initialInfo.known->path }); - continue; - } - - struct stat st; - if (lstat(actualPath.c_str(), &st) == -1) { - if (errno == ENOENT) - throw BuildError( - "builder for '%s' failed to produce output path for output '%s' at '%s'", - worker.store.printStorePath(drvPath), outputName, actualPath); - throw SysError("getting attributes of path '%s'", actualPath); - } - -#ifndef __CYGWIN__ - /* Check that the output is not group or world writable, as - that means that someone else can have interfered with the - build. Also, the output should be owned by the build - user. */ - if ((!S_ISLNK(st.st_mode) && (st.st_mode & (S_IWGRP | S_IWOTH))) || - (buildUser && st.st_uid != buildUser->getUID())) - throw BuildError( - "suspicious ownership or permission on '%s' for output '%s'; rejecting this build output", - actualPath, outputName); -#endif - - /* Canonicalise first. This ensures that the path we're - rewriting doesn't contain a hard link to /etc/shadow or - something like that. */ - canonicalisePathMetaData(actualPath, buildUser ? buildUser->getUID() : -1, inodesSeen); - - debug("scanning for references for output '%s' in temp location '%s'", outputName, actualPath); - - /* Pass blank Sink as we are not ready to hash data at this stage. */ - NullSink blank; - auto references = worker.store.parseStorePathSet( - scanForReferences(blank, actualPath, worker.store.printStorePathSet(referenceablePaths))); - - outputReferencesIfUnregistered.insert_or_assign( - outputName, - PerhapsNeedToRegister { .refs = references }); - outputStats.insert_or_assign(outputName, std::move(st)); - } - - auto sortedOutputNames = topoSort(outputsToSort, - {[&](const std::string & name) { - return std::visit(overloaded { - /* Since we'll use the already installed versions of these, we - can treat them as leaves and ignore any references they - have. */ - [&](AlreadyRegistered _) { return StringSet {}; }, - [&](PerhapsNeedToRegister refs) { - StringSet referencedOutputs; - /* FIXME build inverted map up front so no quadratic waste here */ - for (auto & r : refs.refs) - for (auto & [o, p] : scratchOutputs) - if (r == p) - referencedOutputs.insert(o); - return referencedOutputs; - }, - }, outputReferencesIfUnregistered.at(name)); - }}, - {[&](const std::string & path, const std::string & parent) { - // TODO with more -vvvv also show the temporary paths for manual inspection. - return BuildError( - "cycle detected in build of '%s' in the references of output '%s' from output '%s'", - worker.store.printStorePath(drvPath), path, parent); - }}); - - std::reverse(sortedOutputNames.begin(), sortedOutputNames.end()); - - for (auto & outputName : sortedOutputNames) { - auto output = drv->outputs.at(outputName); - auto & scratchPath = scratchOutputs.at(outputName); - auto actualPath = toRealPathChroot(worker.store.printStorePath(scratchPath)); - - auto finish = [&](StorePath finalStorePath) { - /* Store the final path */ - finalOutputs.insert_or_assign(outputName, finalStorePath); - /* The rewrite rule will be used in downstream outputs that refer to - use. This is why the topological sort is essential to do first - before this for loop. */ - if (scratchPath != finalStorePath) - outputRewrites[std::string { scratchPath.hashPart() }] = std::string { finalStorePath.hashPart() }; - }; - - std::optional referencesOpt = std::visit(overloaded { - [&](AlreadyRegistered skippedFinalPath) -> std::optional { - finish(skippedFinalPath.path); - return std::nullopt; - }, - [&](PerhapsNeedToRegister r) -> std::optional { - return r.refs; - }, - }, outputReferencesIfUnregistered.at(outputName)); - - if (!referencesOpt) - continue; - auto references = *referencesOpt; - - auto rewriteOutput = [&]() { - /* Apply hash rewriting if necessary. */ - if (!outputRewrites.empty()) { - logWarning({ - .name = "Rewriting hashes", - .hint = hintfmt("rewriting hashes in '%1%'; cross fingers", actualPath), - }); - - /* FIXME: this is in-memory. */ - StringSink sink; - dumpPath(actualPath, sink); - deletePath(actualPath); - sink.s = make_ref(rewriteStrings(*sink.s, outputRewrites)); - StringSource source(*sink.s); - restorePath(actualPath, source); - - /* FIXME: set proper permissions in restorePath() so - we don't have to do another traversal. */ - canonicalisePathMetaData(actualPath, -1, inodesSeen); - } - }; - - auto rewriteRefs = [&]() -> std::pair { - /* In the CA case, we need the rewritten refs to calculate the - final path, therefore we look for a *non-rewritten - self-reference, and use a bool rather try to solve the - computationally intractable fixed point. */ - std::pair res { - false, - {}, - }; - for (auto & r : references) { - auto name = r.name(); - auto origHash = std::string { r.hashPart() }; - if (r == scratchPath) - res.first = true; - else if (outputRewrites.count(origHash) == 0) - res.second.insert(r); - else { - std::string newRef = outputRewrites.at(origHash); - newRef += '-'; - newRef += name; - res.second.insert(StorePath { newRef }); - } - } - return res; - }; - - auto newInfoFromCA = [&](const DerivationOutputCAFloating outputHash) -> ValidPathInfo { - auto & st = outputStats.at(outputName); - if (outputHash.method == FileIngestionMethod::Flat) { - /* The output path should be a regular file without execute permission. */ - if (!S_ISREG(st.st_mode) || (st.st_mode & S_IXUSR) != 0) - throw BuildError( - "output path '%1%' should be a non-executable regular file " - "since recursive hashing is not enabled (outputHashMode=flat)", - actualPath); - } - rewriteOutput(); - /* FIXME optimize and deduplicate with addToStore */ - std::string oldHashPart { scratchPath.hashPart() }; - HashModuloSink caSink { outputHash.hashType, oldHashPart }; - switch (outputHash.method) { - case FileIngestionMethod::Recursive: - dumpPath(actualPath, caSink); - break; - case FileIngestionMethod::Flat: - readFile(actualPath, caSink); - break; - } - auto got = caSink.finish().first; - auto refs = rewriteRefs(); - HashModuloSink narSink { htSHA256, oldHashPart }; - dumpPath(actualPath, narSink); - auto narHashAndSize = narSink.finish(); - ValidPathInfo newInfo0 { - worker.store.makeFixedOutputPath( - outputHash.method, - got, - outputPathName(drv->name, outputName), - refs.second, - refs.first), - narHashAndSize.first, - }; - newInfo0.narSize = narHashAndSize.second; - newInfo0.ca = FixedOutputHash { - .method = outputHash.method, - .hash = got, - }; - newInfo0.references = refs.second; - if (refs.first) - newInfo0.references.insert(newInfo0.path); - - assert(newInfo0.ca); - return newInfo0; - }; - - ValidPathInfo newInfo = std::visit(overloaded { - [&](DerivationOutputInputAddressed output) { - /* input-addressed case */ - auto requiredFinalPath = output.path; - /* Preemptively add rewrite rule for final hash, as that is - what the NAR hash will use rather than normalized-self references */ - if (scratchPath != requiredFinalPath) - outputRewrites.insert_or_assign( - std::string { scratchPath.hashPart() }, - std::string { requiredFinalPath.hashPart() }); - rewriteOutput(); - auto narHashAndSize = hashPath(htSHA256, actualPath); - ValidPathInfo newInfo0 { requiredFinalPath, narHashAndSize.first }; - newInfo0.narSize = narHashAndSize.second; - auto refs = rewriteRefs(); - newInfo0.references = refs.second; - if (refs.first) - newInfo0.references.insert(newInfo0.path); - return newInfo0; - }, - [&](DerivationOutputCAFixed dof) { - auto newInfo0 = newInfoFromCA(DerivationOutputCAFloating { - .method = dof.hash.method, - .hashType = dof.hash.hash.type, - }); - - /* Check wanted hash */ - Hash & wanted = dof.hash.hash; - assert(newInfo0.ca); - auto got = getContentAddressHash(*newInfo0.ca); - if (wanted != got) { - /* Throw an error after registering the path as - valid. */ - worker.hashMismatch = true; - delayedException = std::make_exception_ptr( - BuildError("hash mismatch in fixed-output derivation '%s':\n wanted: %s\n got: %s", - worker.store.printStorePath(drvPath), - wanted.to_string(SRI, true), - got.to_string(SRI, true))); - } - return newInfo0; - }, - [&](DerivationOutputCAFloating dof) { - return newInfoFromCA(dof); - }, - }, output.output); - - /* Calculate where we'll move the output files. In the checking case we - will leave leave them where they are, for now, rather than move to - their usual "final destination" */ - auto finalDestPath = worker.store.printStorePath(newInfo.path); - - /* Lock final output path, if not already locked. This happens with - floating CA derivations and hash-mismatching fixed-output - derivations. */ - PathLocks dynamicOutputLock; - auto optFixedPath = output.path(worker.store, drv->name, outputName); - if (!optFixedPath || - worker.store.printStorePath(*optFixedPath) != finalDestPath) - { - assert(newInfo.ca); - dynamicOutputLock.lockPaths({worker.store.toRealPath(finalDestPath)}); - } - - /* Move files, if needed */ - if (worker.store.toRealPath(finalDestPath) != actualPath) { - if (buildMode == bmRepair) { - /* Path already exists, need to replace it */ - replaceValidPath(worker.store.toRealPath(finalDestPath), actualPath); - actualPath = worker.store.toRealPath(finalDestPath); - } else if (buildMode == bmCheck) { - /* Path already exists, and we want to compare, so we leave out - new path in place. */ - } else if (worker.store.isValidPath(newInfo.path)) { - /* Path already exists because CA path produced by something - else. No moving needed. */ - assert(newInfo.ca); - } else { - auto destPath = worker.store.toRealPath(finalDestPath); - movePath(actualPath, destPath); - actualPath = destPath; - } - } - - if (buildMode == bmCheck) { - if (!worker.store.isValidPath(newInfo.path)) continue; - ValidPathInfo oldInfo(*worker.store.queryPathInfo(newInfo.path)); - if (newInfo.narHash != oldInfo.narHash) { - worker.checkMismatch = true; - if (settings.runDiffHook || settings.keepFailed) { - auto dst = worker.store.toRealPath(finalDestPath + checkSuffix); - deletePath(dst); - movePath(actualPath, dst); - - handleDiffHook( - buildUser ? buildUser->getUID() : getuid(), - buildUser ? buildUser->getGID() : getgid(), - finalDestPath, dst, worker.store.printStorePath(drvPath), tmpDir); - - throw NotDeterministic("derivation '%s' may not be deterministic: output '%s' differs from '%s'", - worker.store.printStorePath(drvPath), worker.store.toRealPath(finalDestPath), dst); - } else - throw NotDeterministic("derivation '%s' may not be deterministic: output '%s' differs", - worker.store.printStorePath(drvPath), worker.store.toRealPath(finalDestPath)); - } - - /* Since we verified the build, it's now ultimately trusted. */ - if (!oldInfo.ultimate) { - oldInfo.ultimate = true; - worker.store.signPathInfo(oldInfo); - worker.store.registerValidPaths({ std::move(oldInfo) }); - } - - continue; - } - - /* For debugging, print out the referenced and unreferenced paths. */ - for (auto & i : inputPaths) { - auto j = references.find(i); - if (j == references.end()) - debug("unreferenced input: '%1%'", worker.store.printStorePath(i)); - else - debug("referenced input: '%1%'", worker.store.printStorePath(i)); - } - - if (curRound == nrRounds) { - worker.store.optimisePath(actualPath); // FIXME: combine with scanForReferences() - worker.markContentsGood(newInfo.path); - } - - newInfo.deriver = drvPath; - newInfo.ultimate = true; - worker.store.signPathInfo(newInfo); - - finish(newInfo.path); - - /* If it's a CA path, register it right away. This is necessary if it - isn't statically known so that we can safely unlock the path before - the next iteration */ - if (newInfo.ca) - worker.store.registerValidPaths({newInfo}); - - infos.emplace(outputName, std::move(newInfo)); - } - - if (buildMode == bmCheck) return; - - /* Apply output checks. */ - checkOutputs(infos); - - /* Compare the result with the previous round, and report which - path is different, if any.*/ - if (curRound > 1 && prevInfos != infos) { - assert(prevInfos.size() == infos.size()); - for (auto i = prevInfos.begin(), j = infos.begin(); i != prevInfos.end(); ++i, ++j) - if (!(*i == *j)) { - result.isNonDeterministic = true; - Path prev = worker.store.printStorePath(i->second.path) + checkSuffix; - bool prevExists = keepPreviousRound && pathExists(prev); - hintformat hint = prevExists - ? hintfmt("output '%s' of '%s' differs from '%s' from previous round", - worker.store.printStorePath(i->second.path), worker.store.printStorePath(drvPath), prev) - : hintfmt("output '%s' of '%s' differs from previous round", - worker.store.printStorePath(i->second.path), worker.store.printStorePath(drvPath)); - - handleDiffHook( - buildUser ? buildUser->getUID() : getuid(), - buildUser ? buildUser->getGID() : getgid(), - prev, worker.store.printStorePath(i->second.path), - worker.store.printStorePath(drvPath), tmpDir); - - if (settings.enforceDeterminism) - throw NotDeterministic(hint); - - logError({ - .name = "Output determinism error", - .hint = hint - }); - - curRound = nrRounds; // we know enough, bail out early - } - } - - /* If this is the first round of several, then move the output out of the way. */ - if (nrRounds > 1 && curRound == 1 && curRound < nrRounds && keepPreviousRound) { - for (auto & [_, outputStorePath] : finalOutputs) { - auto path = worker.store.printStorePath(outputStorePath); - Path prev = path + checkSuffix; - deletePath(prev); - Path dst = path + checkSuffix; - if (rename(path.c_str(), dst.c_str())) - throw SysError("renaming '%s' to '%s'", path, dst); - } - } - - if (curRound < nrRounds) { - prevInfos = std::move(infos); - return; - } - - /* Remove the .check directories if we're done. FIXME: keep them - if the result was not determistic? */ - if (curRound == nrRounds) { - for (auto & [_, outputStorePath] : finalOutputs) { - Path prev = worker.store.printStorePath(outputStorePath) + checkSuffix; - deletePath(prev); - } - } - - /* Register each output path as valid, and register the sets of - paths referenced by each of them. If there are cycles in the - outputs, this will fail. */ - { - ValidPathInfos infos2; - for (auto & [outputName, newInfo] : infos) { - infos2.push_back(newInfo); - } - worker.store.registerValidPaths(infos2); - } - - /* In case of a fixed-output derivation hash mismatch, throw an - exception now that we have registered the output as valid. */ - if (delayedException) - std::rethrow_exception(delayedException); - - /* If we made it this far, we are sure the output matches the derivation - (since the delayedException would be a fixed output CA mismatch). That - means it's safe to link the derivation to the output hash. We must do - that for floating CA derivations, which otherwise couldn't be cached, - but it's fine to do in all cases. */ - bool isCaFloating = drv->type() == DerivationType::CAFloating; - - auto drvPathResolved = drvPath; - if (!useDerivation && isCaFloating) { - /* Once a floating CA derivations reaches this point, it - must already be resolved, so we don't bother trying to - downcast drv to get would would just be an empty - inputDrvs field. */ - Derivation drv2 { *drv }; - drvPathResolved = writeDerivation(worker.store, drv2); - } - - if (useDerivation || isCaFloating) - for (auto & [outputName, newInfo] : infos) - worker.store.linkDeriverToPath(drvPathResolved, outputName, newInfo.path); -} - - -void DerivationGoal::checkOutputs(const std::map & outputs) -{ - std::map outputsByPath; - for (auto & output : outputs) - outputsByPath.emplace(worker.store.printStorePath(output.second.path), output.second); - - for (auto & output : outputs) { - auto & outputName = output.first; - auto & info = output.second; - - struct Checks - { - bool ignoreSelfRefs = false; - std::optional maxSize, maxClosureSize; - std::optional allowedReferences, allowedRequisites, disallowedReferences, disallowedRequisites; - }; - - /* Compute the closure and closure size of some output. This - is slightly tricky because some of its references (namely - other outputs) may not be valid yet. */ - auto getClosure = [&](const StorePath & path) - { - uint64_t closureSize = 0; - StorePathSet pathsDone; - std::queue pathsLeft; - pathsLeft.push(path); - - while (!pathsLeft.empty()) { - auto path = pathsLeft.front(); - pathsLeft.pop(); - if (!pathsDone.insert(path).second) continue; - - auto i = outputsByPath.find(worker.store.printStorePath(path)); - if (i != outputsByPath.end()) { - closureSize += i->second.narSize; - for (auto & ref : i->second.references) - pathsLeft.push(ref); - } else { - auto info = worker.store.queryPathInfo(path); - closureSize += info->narSize; - for (auto & ref : info->references) - pathsLeft.push(ref); - } - } - - return std::make_pair(std::move(pathsDone), closureSize); - }; - - auto applyChecks = [&](const Checks & checks) - { - if (checks.maxSize && info.narSize > *checks.maxSize) - throw BuildError("path '%s' is too large at %d bytes; limit is %d bytes", - worker.store.printStorePath(info.path), info.narSize, *checks.maxSize); - - if (checks.maxClosureSize) { - uint64_t closureSize = getClosure(info.path).second; - if (closureSize > *checks.maxClosureSize) - throw BuildError("closure of path '%s' is too large at %d bytes; limit is %d bytes", - worker.store.printStorePath(info.path), closureSize, *checks.maxClosureSize); - } - - auto checkRefs = [&](const std::optional & value, bool allowed, bool recursive) - { - if (!value) return; - - /* Parse a list of reference specifiers. Each element must - either be a store path, or the symbolic name of the output - of the derivation (such as `out'). */ - StorePathSet spec; - for (auto & i : *value) { - if (worker.store.isStorePath(i)) - spec.insert(worker.store.parseStorePath(i)); - else if (finalOutputs.count(i)) - spec.insert(finalOutputs.at(i)); - else throw BuildError("derivation contains an illegal reference specifier '%s'", i); - } - - auto used = recursive - ? getClosure(info.path).first - : info.references; - - if (recursive && checks.ignoreSelfRefs) - used.erase(info.path); - - StorePathSet badPaths; - - for (auto & i : used) - if (allowed) { - if (!spec.count(i)) - badPaths.insert(i); - } else { - if (spec.count(i)) - badPaths.insert(i); - } - - if (!badPaths.empty()) { - string badPathsStr; - for (auto & i : badPaths) { - badPathsStr += "\n "; - badPathsStr += worker.store.printStorePath(i); - } - throw BuildError("output '%s' is not allowed to refer to the following paths:%s", - worker.store.printStorePath(info.path), badPathsStr); - } - }; - - checkRefs(checks.allowedReferences, true, false); - checkRefs(checks.allowedRequisites, true, true); - checkRefs(checks.disallowedReferences, false, false); - checkRefs(checks.disallowedRequisites, false, true); - }; - - if (auto structuredAttrs = parsedDrv->getStructuredAttrs()) { - auto outputChecks = structuredAttrs->find("outputChecks"); - if (outputChecks != structuredAttrs->end()) { - auto output = outputChecks->find(outputName); - - if (output != outputChecks->end()) { - Checks checks; - - auto maxSize = output->find("maxSize"); - if (maxSize != output->end()) - checks.maxSize = maxSize->get(); - - auto maxClosureSize = output->find("maxClosureSize"); - if (maxClosureSize != output->end()) - checks.maxClosureSize = maxClosureSize->get(); - - auto get = [&](const std::string & name) -> std::optional { - auto i = output->find(name); - if (i != output->end()) { - Strings res; - for (auto j = i->begin(); j != i->end(); ++j) { - if (!j->is_string()) - throw Error("attribute '%s' of derivation '%s' must be a list of strings", name, worker.store.printStorePath(drvPath)); - res.push_back(j->get()); - } - checks.disallowedRequisites = res; - return res; - } - return {}; - }; - - checks.allowedReferences = get("allowedReferences"); - checks.allowedRequisites = get("allowedRequisites"); - checks.disallowedReferences = get("disallowedReferences"); - checks.disallowedRequisites = get("disallowedRequisites"); - - applyChecks(checks); - } - } - } else { - // legacy non-structured-attributes case - Checks checks; - checks.ignoreSelfRefs = true; - checks.allowedReferences = parsedDrv->getStringsAttr("allowedReferences"); - checks.allowedRequisites = parsedDrv->getStringsAttr("allowedRequisites"); - checks.disallowedReferences = parsedDrv->getStringsAttr("disallowedReferences"); - checks.disallowedRequisites = parsedDrv->getStringsAttr("disallowedRequisites"); - applyChecks(checks); - } - } -} - - -Path DerivationGoal::openLogFile() -{ - logSize = 0; - - if (!settings.keepLog) return ""; - - auto baseName = std::string(baseNameOf(worker.store.printStorePath(drvPath))); - - /* Create a log file. */ - Path dir = fmt("%s/%s/%s/", worker.store.logDir, worker.store.drvsLogDir, string(baseName, 0, 2)); - createDirs(dir); - - Path logFileName = fmt("%s/%s%s", dir, string(baseName, 2), - settings.compressLog ? ".bz2" : ""); - - fdLogFile = open(logFileName.c_str(), O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0666); - if (!fdLogFile) throw SysError("creating log file '%1%'", logFileName); - - logFileSink = std::make_shared(fdLogFile.get()); - - if (settings.compressLog) - logSink = std::shared_ptr(makeCompressionSink("bzip2", *logFileSink)); - else - logSink = logFileSink; - - return logFileName; -} - - -void DerivationGoal::closeLogFile() -{ - auto logSink2 = std::dynamic_pointer_cast(logSink); - if (logSink2) logSink2->finish(); - if (logFileSink) logFileSink->flush(); - logSink = logFileSink = 0; - fdLogFile = -1; -} - - -void DerivationGoal::deleteTmpDir(bool force) -{ - if (tmpDir != "") { - /* Don't keep temporary directories for builtins because they - might have privileged stuff (like a copy of netrc). */ - if (settings.keepFailed && !force && !drv->isBuiltin()) { - printError("note: keeping build directory '%s'", tmpDir); - chmod(tmpDir.c_str(), 0755); - } - else - deletePath(tmpDir); - tmpDir = ""; - } -} - - -void DerivationGoal::handleChildOutput(int fd, const string & data) -{ - if ((hook && fd == hook->builderOut.readSide.get()) || - (!hook && fd == builderOut.readSide.get())) - { - logSize += data.size(); - if (settings.maxLogSize && logSize > settings.maxLogSize) { - killChild(); - done( - BuildResult::LogLimitExceeded, - Error("%s killed after writing more than %d bytes of log output", - getName(), settings.maxLogSize)); - return; - } - - for (auto c : data) - if (c == '\r') - currentLogLinePos = 0; - else if (c == '\n') - flushLine(); - else { - if (currentLogLinePos >= currentLogLine.size()) - currentLogLine.resize(currentLogLinePos + 1); - currentLogLine[currentLogLinePos++] = c; - } - - if (logSink) (*logSink)(data); - } - - if (hook && fd == hook->fromHook.readSide.get()) { - for (auto c : data) - if (c == '\n') { - handleJSONLogMessage(currentHookLine, worker.act, hook->activities, true); - currentHookLine.clear(); - } else - currentHookLine += c; - } -} - - -void DerivationGoal::handleEOF(int fd) -{ - if (!currentLogLine.empty()) flushLine(); - worker.wakeUp(shared_from_this()); -} - - -void DerivationGoal::flushLine() -{ - if (handleJSONLogMessage(currentLogLine, *act, builderActivities, false)) - ; - - else { - logTail.push_back(currentLogLine); - if (logTail.size() > settings.logLines) logTail.pop_front(); - - act->result(resBuildLogLine, currentLogLine); - } - - currentLogLine = ""; - currentLogLinePos = 0; -} - - -std::map> DerivationGoal::queryPartialDerivationOutputMap() -{ - if (!useDerivation || drv->type() != DerivationType::CAFloating) { - std::map> res; - for (auto & [name, output] : drv->outputs) - res.insert_or_assign(name, output.path(worker.store, drv->name, name)); - return res; - } else { - return worker.store.queryPartialDerivationOutputMap(drvPath); - } -} - -OutputPathMap DerivationGoal::queryDerivationOutputMap() -{ - if (!useDerivation || drv->type() != DerivationType::CAFloating) { - OutputPathMap res; - for (auto & [name, output] : drv->outputsAndOptPaths(worker.store)) - res.insert_or_assign(name, *output.second); - return res; - } else { - return worker.store.queryDerivationOutputMap(drvPath); - } -} - - -void DerivationGoal::checkPathValidity() -{ - bool checkHash = buildMode == bmRepair; - for (auto & i : queryPartialDerivationOutputMap()) { - InitialOutput info { - .wanted = wantOutput(i.first, wantedOutputs), - }; - if (i.second) { - auto outputPath = *i.second; - info.known = { - .path = outputPath, - .status = !worker.store.isValidPath(outputPath) - ? PathStatus::Absent - : !checkHash || worker.pathContentsGood(outputPath) - ? PathStatus::Valid - : PathStatus::Corrupt, - }; - } - initialOutputs.insert_or_assign(i.first, info); - } -} - - -StorePath DerivationGoal::makeFallbackPath(std::string_view outputName) -{ - return worker.store.makeStorePath( - "rewrite:" + std::string(drvPath.to_string()) + ":name:" + std::string(outputName), - Hash(htSHA256), outputPathName(drv->name, outputName)); -} - - -StorePath DerivationGoal::makeFallbackPath(const StorePath & path) -{ - return worker.store.makeStorePath( - "rewrite:" + std::string(drvPath.to_string()) + ":" + std::string(path.to_string()), - Hash(htSHA256), path.name()); -} - - -void DerivationGoal::done(BuildResult::Status status, std::optional ex) -{ - result.status = status; - if (ex) - result.errorMsg = ex->what(); - amDone(result.success() ? ecSuccess : ecFailed, ex); - if (result.status == BuildResult::TimedOut) - worker.timedOut = true; - if (result.status == BuildResult::PermanentFailure) - worker.permanentFailure = true; - - mcExpectedBuilds.reset(); - mcRunningBuilds.reset(); - - if (result.success()) { - if (status == BuildResult::Built) - worker.doneBuilds++; - } else { - if (status != BuildResult::DependencyFailed) - worker.failedBuilds++; - } - - worker.updateProgress(); -} - - -////////////////////////////////////////////////////////////////////// - - -class SubstitutionGoal : public Goal -{ - friend class Worker; - -private: - /* The store path that should be realised through a substitute. */ - StorePath storePath; - - /* The path the substituter refers to the path as. This will be - * different when the stores have different names. */ - std::optional subPath; - - /* The remaining substituters. */ - std::list> subs; - - /* The current substituter. */ - std::shared_ptr sub; - - /* Whether a substituter failed. */ - bool substituterFailed = false; - - /* Path info returned by the substituter's query info operation. */ - std::shared_ptr info; - - /* Pipe for the substituter's standard output. */ - Pipe outPipe; - - /* The substituter thread. */ - std::thread thr; - - std::promise promise; - - /* Whether to try to repair a valid path. */ - RepairFlag repair; - - /* Location where we're downloading the substitute. Differs from - storePath when doing a repair. */ - Path destPath; - - std::unique_ptr> maintainExpectedSubstitutions, - maintainRunningSubstitutions, maintainExpectedNar, maintainExpectedDownload; - - typedef void (SubstitutionGoal::*GoalState)(); - GoalState state; - - /* Content address for recomputing store path */ - std::optional ca; - -public: - SubstitutionGoal(const StorePath & storePath, Worker & worker, RepairFlag repair = NoRepair, std::optional ca = std::nullopt); - ~SubstitutionGoal(); - - void timedOut(Error && ex) override { abort(); }; - - string key() override - { - /* "a$" ensures substitution goals happen before derivation - goals. */ - return "a$" + std::string(storePath.name()) + "$" + worker.store.printStorePath(storePath); - } - - void work() override; - - /* The states. */ - void init(); - void tryNext(); - void gotInfo(); - void referencesValid(); - void tryToRun(); - void finished(); - - /* Callback used by the worker to write to the log. */ - void handleChildOutput(int fd, const string & data) override; - void handleEOF(int fd) override; - - StorePath getStorePath() { return storePath; } -}; - - -SubstitutionGoal::SubstitutionGoal(const StorePath & storePath, Worker & worker, RepairFlag repair, std::optional ca) - : Goal(worker) - , storePath(storePath) - , repair(repair) - , ca(ca) -{ - state = &SubstitutionGoal::init; - name = fmt("substitution of '%s'", worker.store.printStorePath(this->storePath)); - trace("created"); - maintainExpectedSubstitutions = std::make_unique>(worker.expectedSubstitutions); -} - - -SubstitutionGoal::~SubstitutionGoal() -{ - try { - if (thr.joinable()) { - // FIXME: signal worker thread to quit. - thr.join(); - worker.childTerminated(this); - } - } catch (...) { - ignoreException(); - } -} - - -void SubstitutionGoal::work() -{ - (this->*state)(); -} - - -void SubstitutionGoal::init() -{ - trace("init"); - - worker.store.addTempRoot(storePath); - - /* If the path already exists we're done. */ - if (!repair && worker.store.isValidPath(storePath)) { - amDone(ecSuccess); - return; - } - - if (settings.readOnlyMode) - throw Error("cannot substitute path '%s' - no write access to the Nix store", worker.store.printStorePath(storePath)); - - subs = settings.useSubstitutes ? getDefaultSubstituters() : std::list>(); - - tryNext(); -} - - -void SubstitutionGoal::tryNext() -{ - trace("trying next substituter"); - - if (subs.size() == 0) { - /* None left. Terminate this goal and let someone else deal - with it. */ - debug("path '%s' is required, but there is no substituter that can build it", worker.store.printStorePath(storePath)); - - /* Hack: don't indicate failure if there were no substituters. - In that case the calling derivation should just do a - build. */ - amDone(substituterFailed ? ecFailed : ecNoSubstituters); - - if (substituterFailed) { - worker.failedSubstitutions++; - worker.updateProgress(); - } - - return; - } - - sub = subs.front(); - subs.pop_front(); - - if (ca) { - subPath = sub->makeFixedOutputPathFromCA(storePath.name(), *ca); - if (sub->storeDir == worker.store.storeDir) - assert(subPath == storePath); - } else if (sub->storeDir != worker.store.storeDir) { - tryNext(); - return; - } - - try { - // FIXME: make async - info = sub->queryPathInfo(subPath ? *subPath : storePath); - } catch (InvalidPath &) { - tryNext(); - return; - } catch (SubstituterDisabled &) { - if (settings.tryFallback) { - tryNext(); - return; - } - throw; - } catch (Error & e) { - if (settings.tryFallback) { - logError(e.info()); - tryNext(); - return; - } - throw; - } - - if (info->path != storePath) { - if (info->isContentAddressed(*sub) && info->references.empty()) { - auto info2 = std::make_shared(*info); - info2->path = storePath; - info = info2; - } else { - printError("asked '%s' for '%s' but got '%s'", - sub->getUri(), worker.store.printStorePath(storePath), sub->printStorePath(info->path)); - tryNext(); - return; - } - } - - /* Update the total expected download size. */ - auto narInfo = std::dynamic_pointer_cast(info); - - maintainExpectedNar = std::make_unique>(worker.expectedNarSize, info->narSize); - - maintainExpectedDownload = - narInfo && narInfo->fileSize - ? std::make_unique>(worker.expectedDownloadSize, narInfo->fileSize) - : nullptr; - - worker.updateProgress(); - - /* Bail out early if this substituter lacks a valid - signature. LocalStore::addToStore() also checks for this, but - only after we've downloaded the path. */ - if (worker.store.requireSigs - && !sub->isTrusted - && !info->checkSignatures(worker.store, worker.store.getPublicKeys())) - { - logWarning({ - .name = "Invalid path signature", - .hint = hintfmt("substituter '%s' does not have a valid signature for path '%s'", - sub->getUri(), worker.store.printStorePath(storePath)) - }); - tryNext(); - return; - } - - /* To maintain the closure invariant, we first have to realise the - paths referenced by this one. */ - for (auto & i : info->references) - if (i != storePath) /* ignore self-references */ - addWaitee(worker.makeSubstitutionGoal(i)); - - if (waitees.empty()) /* to prevent hang (no wake-up event) */ - referencesValid(); - else - state = &SubstitutionGoal::referencesValid; -} - - -void SubstitutionGoal::referencesValid() -{ - trace("all references realised"); - - if (nrFailed > 0) { - debug("some references of path '%s' could not be realised", worker.store.printStorePath(storePath)); - amDone(nrNoSubstituters > 0 || nrIncompleteClosure > 0 ? ecIncompleteClosure : ecFailed); - return; - } - - for (auto & i : info->references) - if (i != storePath) /* ignore self-references */ - assert(worker.store.isValidPath(i)); - - state = &SubstitutionGoal::tryToRun; - worker.wakeUp(shared_from_this()); -} - - -void SubstitutionGoal::tryToRun() -{ - trace("trying to run"); - - /* Make sure that we are allowed to start a build. Note that even - if maxBuildJobs == 0 (no local builds allowed), we still allow - a substituter to run. This is because substitutions cannot be - distributed to another machine via the build hook. */ - if (worker.getNrLocalBuilds() >= std::max(1U, (unsigned int) settings.maxBuildJobs)) { - worker.waitForBuildSlot(shared_from_this()); - return; - } - - maintainRunningSubstitutions = std::make_unique>(worker.runningSubstitutions); - worker.updateProgress(); - - outPipe.create(); - - promise = std::promise(); - - thr = std::thread([this]() { - try { - /* Wake up the worker loop when we're done. */ - Finally updateStats([this]() { outPipe.writeSide = -1; }); - - Activity act(*logger, actSubstitute, Logger::Fields{worker.store.printStorePath(storePath), sub->getUri()}); - PushActivity pact(act.id); - - copyStorePath(ref(sub), ref(worker.store.shared_from_this()), - subPath ? *subPath : storePath, repair, sub->isTrusted ? NoCheckSigs : CheckSigs); - - promise.set_value(); - } catch (...) { - promise.set_exception(std::current_exception()); - } - }); - - worker.childStarted(shared_from_this(), {outPipe.readSide.get()}, true, false); - - state = &SubstitutionGoal::finished; -} - - -void SubstitutionGoal::finished() -{ - trace("substitute finished"); - - thr.join(); - worker.childTerminated(this); - - try { - promise.get_future().get(); - } catch (std::exception & e) { - printError(e.what()); - - /* Cause the parent build to fail unless --fallback is given, - or the substitute has disappeared. The latter case behaves - the same as the substitute never having existed in the - first place. */ - try { - throw; - } catch (SubstituteGone &) { - } catch (...) { - substituterFailed = true; - } - - /* Try the next substitute. */ - state = &SubstitutionGoal::tryNext; - worker.wakeUp(shared_from_this()); - return; - } - - worker.markContentsGood(storePath); - - printMsg(lvlChatty, "substitution of path '%s' succeeded", worker.store.printStorePath(storePath)); - - maintainRunningSubstitutions.reset(); - - maintainExpectedSubstitutions.reset(); - worker.doneSubstitutions++; - - if (maintainExpectedDownload) { - auto fileSize = maintainExpectedDownload->delta; - maintainExpectedDownload.reset(); - worker.doneDownloadSize += fileSize; - } - - worker.doneNarSize += maintainExpectedNar->delta; - maintainExpectedNar.reset(); - - worker.updateProgress(); - - amDone(ecSuccess); -} - - -void SubstitutionGoal::handleChildOutput(int fd, const string & data) -{ -} - - -void SubstitutionGoal::handleEOF(int fd) -{ - if (fd == outPipe.readSide.get()) worker.wakeUp(shared_from_this()); -} - -////////////////////////////////////////////////////////////////////// - - -Worker::Worker(LocalStore & store) - : act(*logger, actRealise) - , actDerivations(*logger, actBuilds) - , actSubstitutions(*logger, actCopyPaths) - , store(store) -{ - /* Debugging: prevent recursive workers. */ - nrLocalBuilds = 0; - lastWokenUp = steady_time_point::min(); - permanentFailure = false; - timedOut = false; - hashMismatch = false; - checkMismatch = false; -} - - -Worker::~Worker() -{ - /* Explicitly get rid of all strong pointers now. After this all - goals that refer to this worker should be gone. (Otherwise we - are in trouble, since goals may call childTerminated() etc. in - their destructors). */ - topGoals.clear(); - - assert(expectedSubstitutions == 0); - assert(expectedDownloadSize == 0); - assert(expectedNarSize == 0); -} - - -std::shared_ptr Worker::makeDerivationGoalCommon( - const StorePath & drvPath, - const StringSet & wantedOutputs, - std::function()> mkDrvGoal) -{ - WeakGoalPtr & abstract_goal_weak = derivationGoals[drvPath]; - GoalPtr abstract_goal = abstract_goal_weak.lock(); // FIXME - std::shared_ptr goal; - if (!abstract_goal) { - goal = mkDrvGoal(); - abstract_goal_weak = goal; - wakeUp(goal); - } else { - goal = std::dynamic_pointer_cast(abstract_goal); - assert(goal); - goal->addWantedOutputs(wantedOutputs); - } - return goal; -} - - -std::shared_ptr Worker::makeDerivationGoal(const StorePath & drvPath, - const StringSet & wantedOutputs, BuildMode buildMode) -{ - return makeDerivationGoalCommon(drvPath, wantedOutputs, [&]() { - return std::make_shared(drvPath, wantedOutputs, *this, buildMode); - }); -} - - -std::shared_ptr Worker::makeBasicDerivationGoal(const StorePath & drvPath, - const BasicDerivation & drv, const StringSet & wantedOutputs, BuildMode buildMode) -{ - return makeDerivationGoalCommon(drvPath, wantedOutputs, [&]() { - return std::make_shared(drvPath, drv, wantedOutputs, *this, buildMode); - }); -} - - -GoalPtr Worker::makeSubstitutionGoal(const StorePath & path, RepairFlag repair, std::optional ca) -{ - WeakGoalPtr & goal_weak = substitutionGoals[path]; - GoalPtr goal = goal_weak.lock(); // FIXME - if (!goal) { - goal = std::make_shared(path, *this, repair, ca); - goal_weak = goal; - wakeUp(goal); - } - return goal; -} - - -static void removeGoal(GoalPtr goal, WeakGoalMap & goalMap) -{ - /* !!! inefficient */ - for (WeakGoalMap::iterator i = goalMap.begin(); - i != goalMap.end(); ) - if (i->second.lock() == goal) { - WeakGoalMap::iterator j = i; ++j; - goalMap.erase(i); - i = j; - } - else ++i; -} - - -void Worker::removeGoal(GoalPtr goal) -{ - nix::removeGoal(goal, derivationGoals); - nix::removeGoal(goal, substitutionGoals); - if (topGoals.find(goal) != topGoals.end()) { - topGoals.erase(goal); - /* If a top-level goal failed, then kill all other goals - (unless keepGoing was set). */ - if (goal->exitCode == Goal::ecFailed && !settings.keepGoing) - topGoals.clear(); - } - - /* Wake up goals waiting for any goal to finish. */ - for (auto & i : waitingForAnyGoal) { - GoalPtr goal = i.lock(); - if (goal) wakeUp(goal); - } - - waitingForAnyGoal.clear(); -} - - -void Worker::wakeUp(GoalPtr goal) -{ - goal->trace("woken up"); - addToWeakGoals(awake, goal); -} - - -unsigned Worker::getNrLocalBuilds() -{ - return nrLocalBuilds; -} - - -void Worker::childStarted(GoalPtr goal, const set & fds, - bool inBuildSlot, bool respectTimeouts) -{ - Child child; - child.goal = goal; - child.goal2 = goal.get(); - child.fds = fds; - child.timeStarted = child.lastOutput = steady_time_point::clock::now(); - child.inBuildSlot = inBuildSlot; - child.respectTimeouts = respectTimeouts; - children.emplace_back(child); - if (inBuildSlot) nrLocalBuilds++; -} - - -void Worker::childTerminated(Goal * goal, bool wakeSleepers) -{ - auto i = std::find_if(children.begin(), children.end(), - [&](const Child & child) { return child.goal2 == goal; }); - if (i == children.end()) return; - - if (i->inBuildSlot) { - assert(nrLocalBuilds > 0); - nrLocalBuilds--; - } - - children.erase(i); - - if (wakeSleepers) { - - /* Wake up goals waiting for a build slot. */ - for (auto & j : wantingToBuild) { - GoalPtr goal = j.lock(); - if (goal) wakeUp(goal); - } - - wantingToBuild.clear(); - } -} - - -void Worker::waitForBuildSlot(GoalPtr goal) -{ - debug("wait for build slot"); - if (getNrLocalBuilds() < settings.maxBuildJobs) - wakeUp(goal); /* we can do it right away */ - else - addToWeakGoals(wantingToBuild, goal); -} - - -void Worker::waitForAnyGoal(GoalPtr goal) -{ - debug("wait for any goal"); - addToWeakGoals(waitingForAnyGoal, goal); -} - - -void Worker::waitForAWhile(GoalPtr goal) -{ - debug("wait for a while"); - addToWeakGoals(waitingForAWhile, goal); -} - - -void Worker::run(const Goals & _topGoals) -{ - for (auto & i : _topGoals) topGoals.insert(i); - - debug("entered goal loop"); - - while (1) { - - checkInterrupt(); - - store.autoGC(false); - - /* Call every wake goal (in the ordering established by - CompareGoalPtrs). */ - while (!awake.empty() && !topGoals.empty()) { - Goals awake2; - for (auto & i : awake) { - GoalPtr goal = i.lock(); - if (goal) awake2.insert(goal); - } - awake.clear(); - for (auto & goal : awake2) { - checkInterrupt(); - goal->work(); - if (topGoals.empty()) break; // stuff may have been cancelled - } - } - - if (topGoals.empty()) break; - - /* Wait for input. */ - if (!children.empty() || !waitingForAWhile.empty()) - waitForInput(); - else { - if (awake.empty() && 0 == settings.maxBuildJobs) - { - if (getMachines().empty()) - throw Error("unable to start any build; either increase '--max-jobs' " - "or enable remote builds." - "\nhttps://nixos.org/nix/manual/#chap-distributed-builds"); - else - throw Error("unable to start any build; remote machines may not have " - "all required system features." - "\nhttps://nixos.org/nix/manual/#chap-distributed-builds"); - - } - assert(!awake.empty()); - } - } - - /* If --keep-going is not set, it's possible that the main goal - exited while some of its subgoals were still active. But if - --keep-going *is* set, then they must all be finished now. */ - assert(!settings.keepGoing || awake.empty()); - assert(!settings.keepGoing || wantingToBuild.empty()); - assert(!settings.keepGoing || children.empty()); -} - -void Worker::waitForInput() -{ - printMsg(lvlVomit, "waiting for children"); - - /* Process output from the file descriptors attached to the - children, namely log output and output path creation commands. - We also use this to detect child termination: if we get EOF on - the logger pipe of a build, we assume that the builder has - terminated. */ - - bool useTimeout = false; - long timeout = 0; - auto before = steady_time_point::clock::now(); - - /* If we're monitoring for silence on stdout/stderr, or if there - is a build timeout, then wait for input until the first - deadline for any child. */ - auto nearest = steady_time_point::max(); // nearest deadline - if (settings.minFree.get() != 0) - // Periodicallty wake up to see if we need to run the garbage collector. - nearest = before + std::chrono::seconds(10); - for (auto & i : children) { - if (!i.respectTimeouts) continue; - if (0 != settings.maxSilentTime) - nearest = std::min(nearest, i.lastOutput + std::chrono::seconds(settings.maxSilentTime)); - if (0 != settings.buildTimeout) - nearest = std::min(nearest, i.timeStarted + std::chrono::seconds(settings.buildTimeout)); - } - if (nearest != steady_time_point::max()) { - timeout = std::max(1L, (long) std::chrono::duration_cast(nearest - before).count()); - useTimeout = true; - } - - /* If we are polling goals that are waiting for a lock, then wake - up after a few seconds at most. */ - if (!waitingForAWhile.empty()) { - useTimeout = true; - if (lastWokenUp == steady_time_point::min() || lastWokenUp > before) lastWokenUp = before; - timeout = std::max(1L, - (long) std::chrono::duration_cast( - lastWokenUp + std::chrono::seconds(settings.pollInterval) - before).count()); - } else lastWokenUp = steady_time_point::min(); - - if (useTimeout) - vomit("sleeping %d seconds", timeout); - - /* Use select() to wait for the input side of any logger pipe to - become `available'. Note that `available' (i.e., non-blocking) - includes EOF. */ - std::vector pollStatus; - std::map fdToPollStatus; - for (auto & i : children) { - for (auto & j : i.fds) { - pollStatus.push_back((struct pollfd) { .fd = j, .events = POLLIN }); - fdToPollStatus[j] = pollStatus.size() - 1; - } - } - - if (poll(pollStatus.data(), pollStatus.size(), - useTimeout ? timeout * 1000 : -1) == -1) { - if (errno == EINTR) return; - throw SysError("waiting for input"); - } - - auto after = steady_time_point::clock::now(); - - /* Process all available file descriptors. FIXME: this is - O(children * fds). */ - decltype(children)::iterator i; - for (auto j = children.begin(); j != children.end(); j = i) { - i = std::next(j); - - checkInterrupt(); - - GoalPtr goal = j->goal.lock(); - assert(goal); - - set fds2(j->fds); - std::vector buffer(4096); - for (auto & k : fds2) { - if (pollStatus.at(fdToPollStatus.at(k)).revents) { - ssize_t rd = ::read(k, buffer.data(), buffer.size()); - // FIXME: is there a cleaner way to handle pt close - // than EIO? Is this even standard? - if (rd == 0 || (rd == -1 && errno == EIO)) { - debug("%1%: got EOF", goal->getName()); - goal->handleEOF(k); - j->fds.erase(k); - } else if (rd == -1) { - if (errno != EINTR) - throw SysError("%s: read failed", goal->getName()); - } else { - printMsg(lvlVomit, "%1%: read %2% bytes", - goal->getName(), rd); - string data((char *) buffer.data(), rd); - j->lastOutput = after; - goal->handleChildOutput(k, data); - } - } - } - - if (goal->exitCode == Goal::ecBusy && - 0 != settings.maxSilentTime && - j->respectTimeouts && - after - j->lastOutput >= std::chrono::seconds(settings.maxSilentTime)) - { - goal->timedOut(Error( - "%1% timed out after %2% seconds of silence", - goal->getName(), settings.maxSilentTime)); - } - - else if (goal->exitCode == Goal::ecBusy && - 0 != settings.buildTimeout && - j->respectTimeouts && - after - j->timeStarted >= std::chrono::seconds(settings.buildTimeout)) - { - goal->timedOut(Error( - "%1% timed out after %2% seconds", - goal->getName(), settings.buildTimeout)); - } - } - - if (!waitingForAWhile.empty() && lastWokenUp + std::chrono::seconds(settings.pollInterval) <= after) { - lastWokenUp = after; - for (auto & i : waitingForAWhile) { - GoalPtr goal = i.lock(); - if (goal) wakeUp(goal); - } - waitingForAWhile.clear(); - } -} - - -unsigned int Worker::exitStatus() -{ - /* - * 1100100 - * ^^^^ - * |||`- timeout - * ||`-- output hash mismatch - * |`--- build failure - * `---- not deterministic - */ - unsigned int mask = 0; - bool buildFailure = permanentFailure || timedOut || hashMismatch; - if (buildFailure) - mask |= 0x04; // 100 - if (timedOut) - mask |= 0x01; // 101 - if (hashMismatch) - mask |= 0x02; // 102 - if (checkMismatch) { - mask |= 0x08; // 104 - } - - if (mask) - mask |= 0x60; - return mask ? mask : 1; -} - - -bool Worker::pathContentsGood(const StorePath & path) -{ - auto i = pathContentsGoodCache.find(path); - if (i != pathContentsGoodCache.end()) return i->second; - printInfo("checking path '%s'...", store.printStorePath(path)); - auto info = store.queryPathInfo(path); - bool res; - if (!pathExists(store.printStorePath(path))) - res = false; - else { - HashResult current = hashPath(info->narHash.type, store.printStorePath(path)); - Hash nullHash(htSHA256); - res = info->narHash == nullHash || info->narHash == current.first; - } - pathContentsGoodCache.insert_or_assign(path, res); - if (!res) - logError({ - .name = "Corrupted path", - .hint = hintfmt("path '%s' is corrupted or missing!", store.printStorePath(path)) - }); - return res; -} - - -void Worker::markContentsGood(const StorePath & path) -{ - pathContentsGoodCache.insert_or_assign(path, true); -} - - -////////////////////////////////////////////////////////////////////// - - -static void primeCache(Store & store, const std::vector & paths) -{ - StorePathSet willBuild, willSubstitute, unknown; - uint64_t downloadSize, narSize; - store.queryMissing(paths, willBuild, willSubstitute, unknown, downloadSize, narSize); - - if (!willBuild.empty() && 0 == settings.maxBuildJobs && getMachines().empty()) - throw Error( - "%d derivations need to be built, but neither local builds ('--max-jobs') " - "nor remote builds ('--builders') are enabled", willBuild.size()); -} - - -void LocalStore::buildPaths(const std::vector & drvPaths, BuildMode buildMode) -{ - Worker worker(*this); - - primeCache(*this, drvPaths); - - Goals goals; - for (auto & path : drvPaths) { - if (path.path.isDerivation()) - goals.insert(worker.makeDerivationGoal(path.path, path.outputs, buildMode)); - else - goals.insert(worker.makeSubstitutionGoal(path.path, buildMode == bmRepair ? Repair : NoRepair)); - } - - worker.run(goals); - - StorePathSet failed; - std::optional ex; - for (auto & i : goals) { - if (i->ex) { - if (ex) - logError(i->ex->info()); - else - ex = i->ex; - } - if (i->exitCode != Goal::ecSuccess) { - DerivationGoal * i2 = dynamic_cast(i.get()); - if (i2) failed.insert(i2->getDrvPath()); - else failed.insert(dynamic_cast(i.get())->getStorePath()); - } - } - - if (failed.size() == 1 && ex) { - ex->status = worker.exitStatus(); - throw *ex; - } else if (!failed.empty()) { - if (ex) logError(ex->info()); - throw Error(worker.exitStatus(), "build of %s failed", showPaths(failed)); - } -} - -BuildResult LocalStore::buildDerivation(const StorePath & drvPath, const BasicDerivation & drv, - BuildMode buildMode) -{ - Worker worker(*this); - auto goal = worker.makeBasicDerivationGoal(drvPath, drv, {}, buildMode); - - BuildResult result; - - try { - worker.run(Goals{goal}); - result = goal->getResult(); - } catch (Error & e) { - result.status = BuildResult::MiscFailure; - result.errorMsg = e.msg(); - } - - return result; -} - - -void LocalStore::ensurePath(const StorePath & path) -{ - /* If the path is already valid, we're done. */ - if (isValidPath(path)) return; - - primeCache(*this, {{path}}); - - Worker worker(*this); - GoalPtr goal = worker.makeSubstitutionGoal(path); - Goals goals = {goal}; - - worker.run(goals); - - if (goal->exitCode != Goal::ecSuccess) { - if (goal->ex) { - goal->ex->status = worker.exitStatus(); - throw *goal->ex; - } else - throw Error(worker.exitStatus(), "path '%s' does not exist and cannot be created", printStorePath(path)); - } -} - - -void LocalStore::repairPath(const StorePath & path) -{ - Worker worker(*this); - GoalPtr goal = worker.makeSubstitutionGoal(path, Repair); - Goals goals = {goal}; - - worker.run(goals); - - if (goal->exitCode != Goal::ecSuccess) { - /* Since substituting the path didn't work, if we have a valid - deriver, then rebuild the deriver. */ - auto info = queryPathInfo(path); - if (info->deriver && isValidPath(*info->deriver)) { - goals.clear(); - goals.insert(worker.makeDerivationGoal(*info->deriver, StringSet(), bmRepair)); - worker.run(goals); - } else - throw Error(worker.exitStatus(), "cannot repair path '%s'", printStorePath(path)); - } -} - - -} diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc new file mode 100644 index 000000000..5757e5c3f --- /dev/null +++ b/src/libstore/build/worker.cc @@ -0,0 +1,5654 @@ +#include "references.hh" +#include "pathlocks.hh" +#include "globals.hh" +#include "local-store.hh" +#include "util.hh" +#include "archive.hh" +#include "affinity.hh" +#include "builtins.hh" +#include "builtins/buildenv.hh" +#include "filetransfer.hh" +#include "finally.hh" +#include "compression.hh" +#include "json.hh" +#include "nar-info.hh" +#include "parsed-derivations.hh" +#include "machines.hh" +#include "daemon.hh" +#include "worker-protocol.hh" +#include "topo-sort.hh" +#include "callback.hh" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* Includes required for chroot support. */ +#if __linux__ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#if HAVE_SECCOMP +#include +#endif +#define pivot_root(new_root, put_old) (syscall(SYS_pivot_root, new_root, put_old)) +#endif + +#if HAVE_STATVFS +#include +#endif + +#include + + +namespace nix { + +using std::map; + + +static string pathNullDevice = "/dev/null"; + + +/* Forward definition. */ +class Worker; +struct HookInstance; + + +/* A pointer to a goal. */ +struct Goal; +class DerivationGoal; +typedef std::shared_ptr GoalPtr; +typedef std::weak_ptr WeakGoalPtr; + +struct CompareGoalPtrs { + bool operator() (const GoalPtr & a, const GoalPtr & b) const; +}; + +/* Set of goals. */ +typedef set Goals; +typedef list WeakGoals; + +/* A map of paths to goals (and the other way around). */ +typedef std::map WeakGoalMap; + + + +struct Goal : public std::enable_shared_from_this +{ + typedef enum {ecBusy, ecSuccess, ecFailed, ecNoSubstituters, ecIncompleteClosure} ExitCode; + + /* Backlink to the worker. */ + Worker & worker; + + /* Goals that this goal is waiting for. */ + Goals waitees; + + /* Goals waiting for this one to finish. Must use weak pointers + here to prevent cycles. */ + WeakGoals waiters; + + /* Number of goals we are/were waiting for that have failed. */ + unsigned int nrFailed; + + /* Number of substitution goals we are/were waiting for that + failed because there are no substituters. */ + unsigned int nrNoSubstituters; + + /* Number of substitution goals we are/were waiting for that + failed because othey had unsubstitutable references. */ + unsigned int nrIncompleteClosure; + + /* Name of this goal for debugging purposes. */ + string name; + + /* Whether the goal is finished. */ + ExitCode exitCode; + + /* Exception containing an error message, if any. */ + std::optional ex; + + Goal(Worker & worker) : worker(worker) + { + nrFailed = nrNoSubstituters = nrIncompleteClosure = 0; + exitCode = ecBusy; + } + + virtual ~Goal() + { + trace("goal destroyed"); + } + + virtual void work() = 0; + + void addWaitee(GoalPtr waitee); + + virtual void waiteeDone(GoalPtr waitee, ExitCode result); + + virtual void handleChildOutput(int fd, const string & data) + { + abort(); + } + + virtual void handleEOF(int fd) + { + abort(); + } + + void trace(const FormatOrString & fs); + + string getName() + { + return name; + } + + /* Callback in case of a timeout. It should wake up its waiters, + get rid of any running child processes that are being monitored + by the worker (important!), etc. */ + virtual void timedOut(Error && ex) = 0; + + virtual string key() = 0; + + void amDone(ExitCode result, std::optional ex = {}); +}; + + +bool CompareGoalPtrs::operator() (const GoalPtr & a, const GoalPtr & b) const { + string s1 = a->key(); + string s2 = b->key(); + return s1 < s2; +} + + +typedef std::chrono::time_point steady_time_point; + + +/* A mapping used to remember for each child process to what goal it + belongs, and file descriptors for receiving log data and output + path creation commands. */ +struct Child +{ + WeakGoalPtr goal; + Goal * goal2; // ugly hackery + set fds; + bool respectTimeouts; + bool inBuildSlot; + steady_time_point lastOutput; /* time we last got output on stdout/stderr */ + steady_time_point timeStarted; +}; + + +/* The worker class. */ +class Worker +{ +private: + + /* Note: the worker should only have strong pointers to the + top-level goals. */ + + /* The top-level goals of the worker. */ + Goals topGoals; + + /* Goals that are ready to do some work. */ + WeakGoals awake; + + /* Goals waiting for a build slot. */ + WeakGoals wantingToBuild; + + /* Child processes currently running. */ + std::list children; + + /* Number of build slots occupied. This includes local builds and + substitutions but not remote builds via the build hook. */ + unsigned int nrLocalBuilds; + + /* Maps used to prevent multiple instantiations of a goal for the + same derivation / path. */ + WeakGoalMap derivationGoals; + WeakGoalMap substitutionGoals; + + /* Goals waiting for busy paths to be unlocked. */ + WeakGoals waitingForAnyGoal; + + /* Goals sleeping for a few seconds (polling a lock). */ + WeakGoals waitingForAWhile; + + /* Last time the goals in `waitingForAWhile' where woken up. */ + steady_time_point lastWokenUp; + + /* Cache for pathContentsGood(). */ + std::map pathContentsGoodCache; + +public: + + const Activity act; + const Activity actDerivations; + const Activity actSubstitutions; + + /* Set if at least one derivation had a BuildError (i.e. permanent + failure). */ + bool permanentFailure; + + /* Set if at least one derivation had a timeout. */ + bool timedOut; + + /* Set if at least one derivation fails with a hash mismatch. */ + bool hashMismatch; + + /* Set if at least one derivation is not deterministic in check mode. */ + bool checkMismatch; + + LocalStore & store; + + std::unique_ptr hook; + + uint64_t expectedBuilds = 0; + uint64_t doneBuilds = 0; + uint64_t failedBuilds = 0; + uint64_t runningBuilds = 0; + + uint64_t expectedSubstitutions = 0; + uint64_t doneSubstitutions = 0; + uint64_t failedSubstitutions = 0; + uint64_t runningSubstitutions = 0; + uint64_t expectedDownloadSize = 0; + uint64_t doneDownloadSize = 0; + uint64_t expectedNarSize = 0; + uint64_t doneNarSize = 0; + + /* Whether to ask the build hook if it can build a derivation. If + it answers with "decline-permanently", we don't try again. */ + bool tryBuildHook = true; + + Worker(LocalStore & store); + ~Worker(); + + /* Make a goal (with caching). */ + + /* derivation goal */ +private: + std::shared_ptr makeDerivationGoalCommon( + const StorePath & drvPath, const StringSet & wantedOutputs, + std::function()> mkDrvGoal); +public: + std::shared_ptr makeDerivationGoal( + const StorePath & drvPath, + const StringSet & wantedOutputs, BuildMode buildMode = bmNormal); + std::shared_ptr makeBasicDerivationGoal( + const StorePath & drvPath, const BasicDerivation & drv, + const StringSet & wantedOutputs, BuildMode buildMode = bmNormal); + + /* substitution goal */ + GoalPtr makeSubstitutionGoal(const StorePath & storePath, RepairFlag repair = NoRepair, std::optional ca = std::nullopt); + + /* Remove a dead goal. */ + void removeGoal(GoalPtr goal); + + /* Wake up a goal (i.e., there is something for it to do). */ + void wakeUp(GoalPtr goal); + + /* Return the number of local build and substitution processes + currently running (but not remote builds via the build + hook). */ + unsigned int getNrLocalBuilds(); + + /* Registers a running child process. `inBuildSlot' means that + the process counts towards the jobs limit. */ + void childStarted(GoalPtr goal, const set & fds, + bool inBuildSlot, bool respectTimeouts); + + /* Unregisters a running child process. `wakeSleepers' should be + false if there is no sense in waking up goals that are sleeping + because they can't run yet (e.g., there is no free build slot, + or the hook would still say `postpone'). */ + void childTerminated(Goal * goal, bool wakeSleepers = true); + + /* Put `goal' to sleep until a build slot becomes available (which + might be right away). */ + void waitForBuildSlot(GoalPtr goal); + + /* Wait for any goal to finish. Pretty indiscriminate way to + wait for some resource that some other goal is holding. */ + void waitForAnyGoal(GoalPtr goal); + + /* Wait for a few seconds and then retry this goal. Used when + waiting for a lock held by another process. This kind of + polling is inefficient, but POSIX doesn't really provide a way + to wait for multiple locks in the main select() loop. */ + void waitForAWhile(GoalPtr goal); + + /* Loop until the specified top-level goals have finished. */ + void run(const Goals & topGoals); + + /* Wait for input to become available. */ + void waitForInput(); + + unsigned int exitStatus(); + + /* Check whether the given valid path exists and has the right + contents. */ + bool pathContentsGood(const StorePath & path); + + void markContentsGood(const StorePath & path); + + void updateProgress() + { + actDerivations.progress(doneBuilds, expectedBuilds + doneBuilds, runningBuilds, failedBuilds); + actSubstitutions.progress(doneSubstitutions, expectedSubstitutions + doneSubstitutions, runningSubstitutions, failedSubstitutions); + act.setExpected(actFileTransfer, expectedDownloadSize + doneDownloadSize); + act.setExpected(actCopyPath, expectedNarSize + doneNarSize); + } +}; + + +////////////////////////////////////////////////////////////////////// + + +void addToWeakGoals(WeakGoals & goals, GoalPtr p) +{ + // FIXME: necessary? + // FIXME: O(n) + for (auto & i : goals) + if (i.lock() == p) return; + goals.push_back(p); +} + + +void Goal::addWaitee(GoalPtr waitee) +{ + waitees.insert(waitee); + addToWeakGoals(waitee->waiters, shared_from_this()); +} + + +void Goal::waiteeDone(GoalPtr waitee, ExitCode result) +{ + assert(waitees.find(waitee) != waitees.end()); + waitees.erase(waitee); + + trace(fmt("waitee '%s' done; %d left", waitee->name, waitees.size())); + + if (result == ecFailed || result == ecNoSubstituters || result == ecIncompleteClosure) ++nrFailed; + + if (result == ecNoSubstituters) ++nrNoSubstituters; + + if (result == ecIncompleteClosure) ++nrIncompleteClosure; + + if (waitees.empty() || (result == ecFailed && !settings.keepGoing)) { + + /* If we failed and keepGoing is not set, we remove all + remaining waitees. */ + for (auto & goal : waitees) { + WeakGoals waiters2; + for (auto & j : goal->waiters) + if (j.lock() != shared_from_this()) waiters2.push_back(j); + goal->waiters = waiters2; + } + waitees.clear(); + + worker.wakeUp(shared_from_this()); + } +} + + +void Goal::amDone(ExitCode result, std::optional ex) +{ + trace("done"); + assert(exitCode == ecBusy); + assert(result == ecSuccess || result == ecFailed || result == ecNoSubstituters || result == ecIncompleteClosure); + exitCode = result; + + if (ex) { + if (!waiters.empty()) + logError(ex->info()); + else + this->ex = std::move(*ex); + } + + for (auto & i : waiters) { + GoalPtr goal = i.lock(); + if (goal) goal->waiteeDone(shared_from_this(), result); + } + waiters.clear(); + worker.removeGoal(shared_from_this()); +} + + +void Goal::trace(const FormatOrString & fs) +{ + debug("%1%: %2%", name, fs.s); +} + + + +////////////////////////////////////////////////////////////////////// + + +void handleDiffHook( + uid_t uid, uid_t gid, + const Path & tryA, const Path & tryB, + const Path & drvPath, const Path & tmpDir) +{ + auto diffHook = settings.diffHook; + if (diffHook != "" && settings.runDiffHook) { + try { + RunOptions diffHookOptions(diffHook,{tryA, tryB, drvPath, tmpDir}); + diffHookOptions.searchPath = true; + diffHookOptions.uid = uid; + diffHookOptions.gid = gid; + diffHookOptions.chdir = "/"; + + auto diffRes = runProgram(diffHookOptions); + if (!statusOk(diffRes.first)) + throw ExecError(diffRes.first, + "diff-hook program '%1%' %2%", + diffHook, + statusToString(diffRes.first)); + + if (diffRes.second != "") + printError(chomp(diffRes.second)); + } catch (Error & error) { + ErrorInfo ei = error.info(); + ei.hint = hintfmt("diff hook execution failed: %s", + (error.info().hint.has_value() ? error.info().hint->str() : "")); + logError(ei); + } + } +} + +////////////////////////////////////////////////////////////////////// + + +class UserLock +{ +private: + Path fnUserLock; + AutoCloseFD fdUserLock; + + bool isEnabled = false; + string user; + uid_t uid = 0; + gid_t gid = 0; + std::vector supplementaryGIDs; + +public: + UserLock(); + + void kill(); + + string getUser() { return user; } + uid_t getUID() { assert(uid); return uid; } + uid_t getGID() { assert(gid); return gid; } + std::vector getSupplementaryGIDs() { return supplementaryGIDs; } + + bool findFreeUser(); + + bool enabled() { return isEnabled; } + +}; + + +UserLock::UserLock() +{ + assert(settings.buildUsersGroup != ""); + createDirs(settings.nixStateDir + "/userpool"); +} + +bool UserLock::findFreeUser() { + if (enabled()) return true; + + /* Get the members of the build-users-group. */ + struct group * gr = getgrnam(settings.buildUsersGroup.get().c_str()); + if (!gr) + throw Error("the group '%1%' specified in 'build-users-group' does not exist", + settings.buildUsersGroup); + gid = gr->gr_gid; + + /* Copy the result of getgrnam. */ + Strings users; + for (char * * p = gr->gr_mem; *p; ++p) { + debug("found build user '%1%'", *p); + users.push_back(*p); + } + + if (users.empty()) + throw Error("the build users group '%1%' has no members", + settings.buildUsersGroup); + + /* Find a user account that isn't currently in use for another + build. */ + for (auto & i : users) { + debug("trying user '%1%'", i); + + struct passwd * pw = getpwnam(i.c_str()); + if (!pw) + throw Error("the user '%1%' in the group '%2%' does not exist", + i, settings.buildUsersGroup); + + + fnUserLock = (format("%1%/userpool/%2%") % settings.nixStateDir % pw->pw_uid).str(); + + AutoCloseFD fd = open(fnUserLock.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0600); + if (!fd) + throw SysError("opening user lock '%1%'", fnUserLock); + + if (lockFile(fd.get(), ltWrite, false)) { + fdUserLock = std::move(fd); + user = i; + uid = pw->pw_uid; + + /* Sanity check... */ + if (uid == getuid() || uid == geteuid()) + throw Error("the Nix user should not be a member of '%1%'", + settings.buildUsersGroup); + +#if __linux__ + /* Get the list of supplementary groups of this build user. This + is usually either empty or contains a group such as "kvm". */ + supplementaryGIDs.resize(10); + int ngroups = supplementaryGIDs.size(); + int err = getgrouplist(pw->pw_name, pw->pw_gid, + supplementaryGIDs.data(), &ngroups); + if (err == -1) + throw Error("failed to get list of supplementary groups for '%1%'", pw->pw_name); + + supplementaryGIDs.resize(ngroups); +#endif + + isEnabled = true; + return true; + } + } + + return false; +} + +void UserLock::kill() +{ + killUser(uid); +} + + +////////////////////////////////////////////////////////////////////// + + +struct HookInstance +{ + /* Pipes for talking to the build hook. */ + Pipe toHook; + + /* Pipe for the hook's standard output/error. */ + Pipe fromHook; + + /* Pipe for the builder's standard output/error. */ + Pipe builderOut; + + /* The process ID of the hook. */ + Pid pid; + + FdSink sink; + + std::map activities; + + HookInstance(); + + ~HookInstance(); +}; + + +HookInstance::HookInstance() +{ + debug("starting build hook '%s'", settings.buildHook); + + /* Create a pipe to get the output of the child. */ + fromHook.create(); + + /* Create the communication pipes. */ + toHook.create(); + + /* Create a pipe to get the output of the builder. */ + builderOut.create(); + + /* Fork the hook. */ + pid = startProcess([&]() { + + commonChildInit(fromHook); + + if (chdir("/") == -1) throw SysError("changing into /"); + + /* Dup the communication pipes. */ + if (dup2(toHook.readSide.get(), STDIN_FILENO) == -1) + throw SysError("dupping to-hook read side"); + + /* Use fd 4 for the builder's stdout/stderr. */ + if (dup2(builderOut.writeSide.get(), 4) == -1) + throw SysError("dupping builder's stdout/stderr"); + + /* Hack: pass the read side of that fd to allow build-remote + to read SSH error messages. */ + if (dup2(builderOut.readSide.get(), 5) == -1) + throw SysError("dupping builder's stdout/stderr"); + + Strings args = { + std::string(baseNameOf(settings.buildHook.get())), + std::to_string(verbosity), + }; + + execv(settings.buildHook.get().c_str(), stringsToCharPtrs(args).data()); + + throw SysError("executing '%s'", settings.buildHook); + }); + + pid.setSeparatePG(true); + fromHook.writeSide = -1; + toHook.readSide = -1; + + sink = FdSink(toHook.writeSide.get()); + std::map settings; + globalConfig.getSettings(settings); + for (auto & setting : settings) + sink << 1 << setting.first << setting.second.value; + sink << 0; +} + + +HookInstance::~HookInstance() +{ + try { + toHook.writeSide = -1; + if (pid != -1) pid.kill(); + } catch (...) { + ignoreException(); + } +} + + +////////////////////////////////////////////////////////////////////// + + +typedef enum {rpAccept, rpDecline, rpPostpone} HookReply; + +class SubstitutionGoal; + +/* Unless we are repairing, we don't both to test validity and just assume it, + so the choices are `Absent` or `Valid`. */ +enum struct PathStatus { + Corrupt, + Absent, + Valid, +}; + +struct InitialOutputStatus { + StorePath path; + PathStatus status; + /* Valid in the store, and additionally non-corrupt if we are repairing */ + bool isValid() const { + return status == PathStatus::Valid; + } + /* Merely present, allowed to be corrupt */ + bool isPresent() const { + return status == PathStatus::Corrupt + || status == PathStatus::Valid; + } +}; + +struct InitialOutput { + bool wanted; + std::optional known; +}; + +class DerivationGoal : public Goal +{ +private: + /* Whether to use an on-disk .drv file. */ + bool useDerivation; + + /* The path of the derivation. */ + StorePath drvPath; + + /* The specific outputs that we need to build. Empty means all of + them. */ + StringSet wantedOutputs; + + /* Whether additional wanted outputs have been added. */ + bool needRestart = false; + + /* Whether to retry substituting the outputs after building the + inputs. */ + bool retrySubstitution; + + /* The derivation stored at drvPath. */ + std::unique_ptr drv; + + std::unique_ptr parsedDrv; + + /* The remainder is state held during the build. */ + + /* Locks on (fixed) output paths. */ + PathLocks outputLocks; + + /* All input paths (that is, the union of FS closures of the + immediate input paths). */ + StorePathSet inputPaths; + + std::map initialOutputs; + + /* User selected for running the builder. */ + std::unique_ptr buildUser; + + /* The process ID of the builder. */ + Pid pid; + + /* The temporary directory. */ + Path tmpDir; + + /* The path of the temporary directory in the sandbox. */ + Path tmpDirInSandbox; + + /* File descriptor for the log file. */ + AutoCloseFD fdLogFile; + std::shared_ptr logFileSink, logSink; + + /* Number of bytes received from the builder's stdout/stderr. */ + unsigned long logSize; + + /* The most recent log lines. */ + std::list logTail; + + std::string currentLogLine; + size_t currentLogLinePos = 0; // to handle carriage return + + std::string currentHookLine; + + /* Pipe for the builder's standard output/error. */ + Pipe builderOut; + + /* Pipe for synchronising updates to the builder namespaces. */ + Pipe userNamespaceSync; + + /* The mount namespace of the builder, used to add additional + paths to the sandbox as a result of recursive Nix calls. */ + AutoCloseFD sandboxMountNamespace; + + /* On Linux, whether we're doing the build in its own user + namespace. */ + bool usingUserNamespace = true; + + /* The build hook. */ + std::unique_ptr hook; + + /* Whether we're currently doing a chroot build. */ + bool useChroot = false; + + Path chrootRootDir; + + /* RAII object to delete the chroot directory. */ + std::shared_ptr autoDelChroot; + + /* The sort of derivation we are building. */ + DerivationType derivationType; + + /* Whether to run the build in a private network namespace. */ + bool privateNetwork = false; + + typedef void (DerivationGoal::*GoalState)(); + GoalState state; + + /* Stuff we need to pass to initChild(). */ + struct ChrootPath { + Path source; + bool optional; + ChrootPath(Path source = "", bool optional = false) + : source(source), optional(optional) + { } + }; + typedef map DirsInChroot; // maps target path to source path + DirsInChroot dirsInChroot; + + typedef map Environment; + Environment env; + +#if __APPLE__ + typedef string SandboxProfile; + SandboxProfile additionalSandboxProfile; +#endif + + /* Hash rewriting. */ + StringMap inputRewrites, outputRewrites; + typedef map RedirectedOutputs; + RedirectedOutputs redirectedOutputs; + + /* The outputs paths used during the build. + + - Input-addressed derivations or fixed content-addressed outputs are + sometimes built when some of their outputs already exist, and can not + be hidden via sandboxing. We use temporary locations instead and + rewrite after the build. Otherwise the regular predetermined paths are + put here. + + - Floating content-addressed derivations do not know their final build + output paths until the outputs are hashed, so random locations are + used, and then renamed. The randomness helps guard against hidden + self-references. + */ + OutputPathMap scratchOutputs; + + /* The final output paths of the build. + + - For input-addressed derivations, always the precomputed paths + + - For content-addressed derivations, calcuated from whatever the hash + ends up being. (Note that fixed outputs derivations that produce the + "wrong" output still install that data under its true content-address.) + */ + OutputPathMap finalOutputs; + + BuildMode buildMode; + + /* If we're repairing without a chroot, there may be outputs that + are valid but corrupt. So we redirect these outputs to + temporary paths. */ + StorePathSet redirectedBadOutputs; + + BuildResult result; + + /* The current round, if we're building multiple times. */ + size_t curRound = 1; + + size_t nrRounds; + + /* Path registration info from the previous round, if we're + building multiple times. Since this contains the hash, it + allows us to compare whether two rounds produced the same + result. */ + std::map prevInfos; + + uid_t sandboxUid() { return usingUserNamespace ? 1000 : buildUser->getUID(); } + gid_t sandboxGid() { return usingUserNamespace ? 100 : buildUser->getGID(); } + + const static Path homeDir; + + std::unique_ptr> mcExpectedBuilds, mcRunningBuilds; + + std::unique_ptr act; + + /* Activity that denotes waiting for a lock. */ + std::unique_ptr actLock; + + std::map builderActivities; + + /* The remote machine on which we're building. */ + std::string machineName; + + /* The recursive Nix daemon socket. */ + AutoCloseFD daemonSocket; + + /* The daemon main thread. */ + std::thread daemonThread; + + /* The daemon worker threads. */ + std::vector daemonWorkerThreads; + + /* Paths that were added via recursive Nix calls. */ + StorePathSet addedPaths; + + /* Recursive Nix calls are only allowed to build or realize paths + in the original input closure or added via a recursive Nix call + (so e.g. you can't do 'nix-store -r /nix/store/' where + /nix/store/ is some arbitrary path in a binary cache). */ + bool isAllowed(const StorePath & path) + { + return inputPaths.count(path) || addedPaths.count(path); + } + + friend struct RestrictedStore; + +public: + DerivationGoal(const StorePath & drvPath, + const StringSet & wantedOutputs, Worker & worker, + BuildMode buildMode = bmNormal); + DerivationGoal(const StorePath & drvPath, const BasicDerivation & drv, + const StringSet & wantedOutputs, Worker & worker, + BuildMode buildMode = bmNormal); + ~DerivationGoal(); + + /* Whether we need to perform hash rewriting if there are valid output paths. */ + bool needsHashRewrite(); + + void timedOut(Error && ex) override; + + string key() override + { + /* Ensure that derivations get built in order of their name, + i.e. a derivation named "aardvark" always comes before + "baboon". And substitution goals always happen before + derivation goals (due to "b$"). */ + return "b$" + std::string(drvPath.name()) + "$" + worker.store.printStorePath(drvPath); + } + + void work() override; + + StorePath getDrvPath() + { + return drvPath; + } + + /* Add wanted outputs to an already existing derivation goal. */ + void addWantedOutputs(const StringSet & outputs); + + BuildResult getResult() { return result; } + +private: + /* The states. */ + void getDerivation(); + void loadDerivation(); + void haveDerivation(); + void outputsSubstitutionTried(); + void gaveUpOnSubstitution(); + void closureRepaired(); + void inputsRealised(); + void tryToBuild(); + void tryLocalBuild(); + void buildDone(); + + void resolvedFinished(); + + /* Is the build hook willing to perform the build? */ + HookReply tryBuildHook(); + + /* Start building a derivation. */ + void startBuilder(); + + /* Fill in the environment for the builder. */ + void initEnv(); + + /* Setup tmp dir location. */ + void initTmpDir(); + + /* Write a JSON file containing the derivation attributes. */ + void writeStructuredAttrs(); + + void startDaemon(); + + void stopDaemon(); + + /* Add 'path' to the set of paths that may be referenced by the + outputs, and make it appear in the sandbox. */ + void addDependency(const StorePath & path); + + /* Make a file owned by the builder. */ + void chownToBuilder(const Path & path); + + /* Run the builder's process. */ + void runChild(); + + friend int childEntry(void *); + + /* Check that the derivation outputs all exist and register them + as valid. */ + void registerOutputs(); + + /* Check that an output meets the requirements specified by the + 'outputChecks' attribute (or the legacy + '{allowed,disallowed}{References,Requisites}' attributes). */ + void checkOutputs(const std::map & outputs); + + /* Open a log file and a pipe to it. */ + Path openLogFile(); + + /* Close the log file. */ + void closeLogFile(); + + /* Delete the temporary directory, if we have one. */ + void deleteTmpDir(bool force); + + /* Callback used by the worker to write to the log. */ + void handleChildOutput(int fd, const string & data) override; + void handleEOF(int fd) override; + void flushLine(); + + /* Wrappers around the corresponding Store methods that first consult the + derivation. This is currently needed because when there is no drv file + there also is no DB entry. */ + std::map> queryPartialDerivationOutputMap(); + OutputPathMap queryDerivationOutputMap(); + + /* Return the set of (in)valid paths. */ + void checkPathValidity(); + + /* Forcibly kill the child process, if any. */ + void killChild(); + + /* Create alternative path calculated from but distinct from the + input, so we can avoid overwriting outputs (or other store paths) + that already exist. */ + StorePath makeFallbackPath(const StorePath & path); + /* Make a path to another based on the output name along with the + derivation hash. */ + /* FIXME add option to randomize, so we can audit whether our + rewrites caught everything */ + StorePath makeFallbackPath(std::string_view outputName); + + void repairClosure(); + + void started(); + + void done( + BuildResult::Status status, + std::optional ex = {}); + + StorePathSet exportReferences(const StorePathSet & storePaths); +}; + + +const Path DerivationGoal::homeDir = "/homeless-shelter"; + + +DerivationGoal::DerivationGoal(const StorePath & drvPath, + const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode) + : Goal(worker) + , useDerivation(true) + , drvPath(drvPath) + , wantedOutputs(wantedOutputs) + , buildMode(buildMode) +{ + state = &DerivationGoal::getDerivation; + name = fmt( + "building of '%s' from .drv file", + StorePathWithOutputs { drvPath, wantedOutputs }.to_string(worker.store)); + trace("created"); + + mcExpectedBuilds = std::make_unique>(worker.expectedBuilds); + worker.updateProgress(); +} + + +DerivationGoal::DerivationGoal(const StorePath & drvPath, const BasicDerivation & drv, + const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode) + : Goal(worker) + , useDerivation(false) + , drvPath(drvPath) + , wantedOutputs(wantedOutputs) + , buildMode(buildMode) +{ + this->drv = std::make_unique(BasicDerivation(drv)); + state = &DerivationGoal::haveDerivation; + name = fmt( + "building of '%s' from in-memory derivation", + StorePathWithOutputs { drvPath, drv.outputNames() }.to_string(worker.store)); + trace("created"); + + mcExpectedBuilds = std::make_unique>(worker.expectedBuilds); + worker.updateProgress(); + + /* Prevent the .chroot directory from being + garbage-collected. (See isActiveTempFile() in gc.cc.) */ + worker.store.addTempRoot(this->drvPath); +} + + +DerivationGoal::~DerivationGoal() +{ + /* Careful: we should never ever throw an exception from a + destructor. */ + try { killChild(); } catch (...) { ignoreException(); } + try { stopDaemon(); } catch (...) { ignoreException(); } + try { deleteTmpDir(false); } catch (...) { ignoreException(); } + try { closeLogFile(); } catch (...) { ignoreException(); } +} + + +inline bool DerivationGoal::needsHashRewrite() +{ +#if __linux__ + return !useChroot; +#else + /* Darwin requires hash rewriting even when sandboxing is enabled. */ + return true; +#endif +} + + +void DerivationGoal::killChild() +{ + if (pid != -1) { + worker.childTerminated(this); + + if (buildUser) { + /* If we're using a build user, then there is a tricky + race condition: if we kill the build user before the + child has done its setuid() to the build user uid, then + it won't be killed, and we'll potentially lock up in + pid.wait(). So also send a conventional kill to the + child. */ + ::kill(-pid, SIGKILL); /* ignore the result */ + buildUser->kill(); + pid.wait(); + } else + pid.kill(); + + assert(pid == -1); + } + + hook.reset(); +} + + +void DerivationGoal::timedOut(Error && ex) +{ + killChild(); + done(BuildResult::TimedOut, ex); +} + + +void DerivationGoal::work() +{ + (this->*state)(); +} + + +void DerivationGoal::addWantedOutputs(const StringSet & outputs) +{ + /* If we already want all outputs, there is nothing to do. */ + if (wantedOutputs.empty()) return; + + if (outputs.empty()) { + wantedOutputs.clear(); + needRestart = true; + } else + for (auto & i : outputs) + if (wantedOutputs.insert(i).second) + needRestart = true; +} + + +void DerivationGoal::getDerivation() +{ + trace("init"); + + /* The first thing to do is to make sure that the derivation + exists. If it doesn't, it may be created through a + substitute. */ + if (buildMode == bmNormal && worker.store.isValidPath(drvPath)) { + loadDerivation(); + return; + } + + addWaitee(worker.makeSubstitutionGoal(drvPath)); + + state = &DerivationGoal::loadDerivation; +} + + +void DerivationGoal::loadDerivation() +{ + trace("loading derivation"); + + if (nrFailed != 0) { + done(BuildResult::MiscFailure, Error("cannot build missing derivation '%s'", worker.store.printStorePath(drvPath))); + return; + } + + /* `drvPath' should already be a root, but let's be on the safe + side: if the user forgot to make it a root, we wouldn't want + things being garbage collected while we're busy. */ + worker.store.addTempRoot(drvPath); + + assert(worker.store.isValidPath(drvPath)); + + /* Get the derivation. */ + drv = std::unique_ptr(new Derivation(worker.store.derivationFromPath(drvPath))); + + haveDerivation(); +} + + +void DerivationGoal::haveDerivation() +{ + trace("have derivation"); + + if (drv->type() == DerivationType::CAFloating) + settings.requireExperimentalFeature("ca-derivations"); + + retrySubstitution = false; + + for (auto & i : drv->outputsAndOptPaths(worker.store)) + if (i.second.second) + worker.store.addTempRoot(*i.second.second); + + /* Check what outputs paths are not already valid. */ + checkPathValidity(); + bool allValid = true; + for (auto & [_, status] : initialOutputs) { + if (!status.wanted) continue; + if (!status.known || !status.known->isValid()) { + allValid = false; + break; + } + } + + /* If they are all valid, then we're done. */ + if (allValid && buildMode == bmNormal) { + done(BuildResult::AlreadyValid); + return; + } + + parsedDrv = std::make_unique(drvPath, *drv); + + + /* We are first going to try to create the invalid output paths + through substitutes. If that doesn't work, we'll build + them. */ + if (settings.useSubstitutes && parsedDrv->substitutesAllowed()) + for (auto & [_, status] : initialOutputs) { + if (!status.wanted) continue; + if (!status.known) { + warn("do not know how to query for unknown floating content-addressed derivation output yet"); + /* Nothing to wait for; tail call */ + return DerivationGoal::gaveUpOnSubstitution(); + } + addWaitee(worker.makeSubstitutionGoal( + status.known->path, + buildMode == bmRepair ? Repair : NoRepair, + getDerivationCA(*drv))); + } + + if (waitees.empty()) /* to prevent hang (no wake-up event) */ + outputsSubstitutionTried(); + else + state = &DerivationGoal::outputsSubstitutionTried; +} + + +void DerivationGoal::outputsSubstitutionTried() +{ + trace("all outputs substituted (maybe)"); + + if (nrFailed > 0 && nrFailed > nrNoSubstituters + nrIncompleteClosure && !settings.tryFallback) { + done(BuildResult::TransientFailure, + fmt("some substitutes for the outputs of derivation '%s' failed (usually happens due to networking issues); try '--fallback' to build derivation from source ", + worker.store.printStorePath(drvPath))); + return; + } + + /* If the substitutes form an incomplete closure, then we should + build the dependencies of this derivation, but after that, we + can still use the substitutes for this derivation itself. */ + if (nrIncompleteClosure > 0) retrySubstitution = true; + + nrFailed = nrNoSubstituters = nrIncompleteClosure = 0; + + if (needRestart) { + needRestart = false; + haveDerivation(); + return; + } + + checkPathValidity(); + size_t nrInvalid = 0; + for (auto & [_, status] : initialOutputs) { + if (!status.wanted) continue; + if (!status.known || !status.known->isValid()) + nrInvalid++; + } + + if (buildMode == bmNormal && nrInvalid == 0) { + done(BuildResult::Substituted); + return; + } + if (buildMode == bmRepair && nrInvalid == 0) { + repairClosure(); + return; + } + if (buildMode == bmCheck && nrInvalid > 0) + throw Error("some outputs of '%s' are not valid, so checking is not possible", + worker.store.printStorePath(drvPath)); + + /* Nothing to wait for; tail call */ + gaveUpOnSubstitution(); +} + +/* At least one of the output paths could not be + produced using a substitute. So we have to build instead. */ +void DerivationGoal::gaveUpOnSubstitution() +{ + /* Make sure checkPathValidity() from now on checks all + outputs. */ + wantedOutputs.clear(); + + /* The inputs must be built before we can build this goal. */ + if (useDerivation) + for (auto & i : dynamic_cast(drv.get())->inputDrvs) + addWaitee(worker.makeDerivationGoal(i.first, i.second, buildMode == bmRepair ? bmRepair : bmNormal)); + + for (auto & i : drv->inputSrcs) { + if (worker.store.isValidPath(i)) continue; + if (!settings.useSubstitutes) + throw Error("dependency '%s' of '%s' does not exist, and substitution is disabled", + worker.store.printStorePath(i), worker.store.printStorePath(drvPath)); + addWaitee(worker.makeSubstitutionGoal(i)); + } + + if (waitees.empty()) /* to prevent hang (no wake-up event) */ + inputsRealised(); + else + state = &DerivationGoal::inputsRealised; +} + + +void DerivationGoal::repairClosure() +{ + /* If we're repairing, we now know that our own outputs are valid. + Now check whether the other paths in the outputs closure are + good. If not, then start derivation goals for the derivations + that produced those outputs. */ + + /* Get the output closure. */ + auto outputs = queryDerivationOutputMap(); + StorePathSet outputClosure; + for (auto & i : outputs) { + if (!wantOutput(i.first, wantedOutputs)) continue; + worker.store.computeFSClosure(i.second, outputClosure); + } + + /* Filter out our own outputs (which we have already checked). */ + for (auto & i : outputs) + outputClosure.erase(i.second); + + /* Get all dependencies of this derivation so that we know which + derivation is responsible for which path in the output + closure. */ + StorePathSet inputClosure; + if (useDerivation) worker.store.computeFSClosure(drvPath, inputClosure); + std::map outputsToDrv; + for (auto & i : inputClosure) + if (i.isDerivation()) { + auto depOutputs = worker.store.queryPartialDerivationOutputMap(i); + for (auto & j : depOutputs) + if (j.second) + outputsToDrv.insert_or_assign(*j.second, i); + } + + /* Check each path (slow!). */ + for (auto & i : outputClosure) { + if (worker.pathContentsGood(i)) continue; + logError({ + .name = "Corrupt path in closure", + .hint = hintfmt( + "found corrupted or missing path '%s' in the output closure of '%s'", + worker.store.printStorePath(i), worker.store.printStorePath(drvPath)) + }); + auto drvPath2 = outputsToDrv.find(i); + if (drvPath2 == outputsToDrv.end()) + addWaitee(worker.makeSubstitutionGoal(i, Repair)); + else + addWaitee(worker.makeDerivationGoal(drvPath2->second, StringSet(), bmRepair)); + } + + if (waitees.empty()) { + done(BuildResult::AlreadyValid); + return; + } + + state = &DerivationGoal::closureRepaired; +} + + +void DerivationGoal::closureRepaired() +{ + trace("closure repaired"); + if (nrFailed > 0) + throw Error("some paths in the output closure of derivation '%s' could not be repaired", + worker.store.printStorePath(drvPath)); + done(BuildResult::AlreadyValid); +} + + +void DerivationGoal::inputsRealised() +{ + trace("all inputs realised"); + + if (nrFailed != 0) { + if (!useDerivation) + throw Error("some dependencies of '%s' are missing", worker.store.printStorePath(drvPath)); + done(BuildResult::DependencyFailed, Error( + "%s dependencies of derivation '%s' failed to build", + nrFailed, worker.store.printStorePath(drvPath))); + return; + } + + if (retrySubstitution) { + haveDerivation(); + return; + } + + /* Gather information necessary for computing the closure and/or + running the build hook. */ + + /* Determine the full set of input paths. */ + + /* First, the input derivations. */ + if (useDerivation) { + auto & fullDrv = *dynamic_cast(drv.get()); + + if (!fullDrv.inputDrvs.empty() && fullDrv.type() == DerivationType::CAFloating) { + /* We are be able to resolve this derivation based on the + now-known results of dependencies. If so, we become a stub goal + aliasing that resolved derivation goal */ + std::optional attempt = fullDrv.tryResolve(worker.store); + assert(attempt); + Derivation drvResolved { *std::move(attempt) }; + + auto pathResolved = writeDerivation(worker.store, drvResolved); + /* Add to memotable to speed up downstream goal's queries with the + original derivation. */ + drvPathResolutions.lock()->insert_or_assign(drvPath, pathResolved); + + auto msg = fmt("Resolved derivation: '%s' -> '%s'", + worker.store.printStorePath(drvPath), + worker.store.printStorePath(pathResolved)); + act = std::make_unique(*logger, lvlInfo, actBuildWaiting, msg, + Logger::Fields { + worker.store.printStorePath(drvPath), + worker.store.printStorePath(pathResolved), + }); + + auto resolvedGoal = worker.makeDerivationGoal( + pathResolved, wantedOutputs, buildMode); + addWaitee(resolvedGoal); + + state = &DerivationGoal::resolvedFinished; + return; + } + + for (auto & [depDrvPath, wantedDepOutputs] : fullDrv.inputDrvs) { + /* Add the relevant output closures of the input derivation + `i' as input paths. Only add the closures of output paths + that are specified as inputs. */ + assert(worker.store.isValidPath(drvPath)); + auto outputs = worker.store.queryPartialDerivationOutputMap(depDrvPath); + for (auto & j : wantedDepOutputs) { + if (outputs.count(j) > 0) { + auto optRealizedInput = outputs.at(j); + if (!optRealizedInput) + throw Error( + "derivation '%s' requires output '%s' from input derivation '%s', which is supposedly realized already, yet we still don't know what path corresponds to that output", + worker.store.printStorePath(drvPath), j, worker.store.printStorePath(drvPath)); + worker.store.computeFSClosure(*optRealizedInput, inputPaths); + } else + throw Error( + "derivation '%s' requires non-existent output '%s' from input derivation '%s'", + worker.store.printStorePath(drvPath), j, worker.store.printStorePath(drvPath)); + } + } + } + + /* Second, the input sources. */ + worker.store.computeFSClosure(drv->inputSrcs, inputPaths); + + debug("added input paths %s", worker.store.showPaths(inputPaths)); + + /* What type of derivation are we building? */ + derivationType = drv->type(); + + /* Don't repeat fixed-output derivations since they're already + verified by their output hash.*/ + nrRounds = derivationIsFixed(derivationType) ? 1 : settings.buildRepeat + 1; + + /* Okay, try to build. Note that here we don't wait for a build + slot to become available, since we don't need one if there is a + build hook. */ + state = &DerivationGoal::tryToBuild; + worker.wakeUp(shared_from_this()); + + result = BuildResult(); +} + +void DerivationGoal::started() { + auto msg = fmt( + buildMode == bmRepair ? "repairing outputs of '%s'" : + buildMode == bmCheck ? "checking outputs of '%s'" : + nrRounds > 1 ? "building '%s' (round %d/%d)" : + "building '%s'", worker.store.printStorePath(drvPath), curRound, nrRounds); + fmt("building '%s'", worker.store.printStorePath(drvPath)); + if (hook) msg += fmt(" on '%s'", machineName); + act = std::make_unique(*logger, lvlInfo, actBuild, msg, + Logger::Fields{worker.store.printStorePath(drvPath), hook ? machineName : "", curRound, nrRounds}); + mcRunningBuilds = std::make_unique>(worker.runningBuilds); + worker.updateProgress(); +} + +void DerivationGoal::tryToBuild() +{ + trace("trying to build"); + + /* Obtain locks on all output paths, if the paths are known a priori. + + The locks are automatically released when we exit this function or Nix + crashes. If we can't acquire the lock, then continue; hopefully some + other goal can start a build, and if not, the main loop will sleep a few + seconds and then retry this goal. */ + PathSet lockFiles; + /* FIXME: Should lock something like the drv itself so we don't build same + CA drv concurrently */ + for (auto & i : drv->outputsAndOptPaths(worker.store)) + if (i.second.second) + lockFiles.insert(worker.store.Store::toRealPath(*i.second.second)); + + if (!outputLocks.lockPaths(lockFiles, "", false)) { + if (!actLock) + actLock = std::make_unique(*logger, lvlWarn, actBuildWaiting, + fmt("waiting for lock on %s", yellowtxt(showPaths(lockFiles)))); + worker.waitForAWhile(shared_from_this()); + return; + } + + actLock.reset(); + + /* Now check again whether the outputs are valid. This is because + another process may have started building in parallel. After + it has finished and released the locks, we can (and should) + reuse its results. (Strictly speaking the first check can be + omitted, but that would be less efficient.) Note that since we + now hold the locks on the output paths, no other process can + build this derivation, so no further checks are necessary. */ + checkPathValidity(); + bool allValid = true; + for (auto & [_, status] : initialOutputs) { + if (!status.wanted) continue; + if (!status.known || !status.known->isValid()) { + allValid = false; + break; + } + } + if (buildMode != bmCheck && allValid) { + debug("skipping build of derivation '%s', someone beat us to it", worker.store.printStorePath(drvPath)); + outputLocks.setDeletion(true); + done(BuildResult::AlreadyValid); + return; + } + + /* If any of the outputs already exist but are not valid, delete + them. */ + for (auto & [_, status] : initialOutputs) { + if (!status.known || status.known->isValid()) continue; + auto storePath = status.known->path; + debug("removing invalid path '%s'", worker.store.printStorePath(status.known->path)); + deletePath(worker.store.Store::toRealPath(storePath)); + } + + /* Don't do a remote build if the derivation has the attribute + `preferLocalBuild' set. Also, check and repair modes are only + supported for local builds. */ + bool buildLocally = buildMode != bmNormal || parsedDrv->willBuildLocally(worker.store); + + if (!buildLocally) { + switch (tryBuildHook()) { + case rpAccept: + /* Yes, it has started doing so. Wait until we get + EOF from the hook. */ + actLock.reset(); + result.startTime = time(0); // inexact + state = &DerivationGoal::buildDone; + started(); + return; + case rpPostpone: + /* Not now; wait until at least one child finishes or + the wake-up timeout expires. */ + if (!actLock) + actLock = std::make_unique(*logger, lvlWarn, actBuildWaiting, + fmt("waiting for a machine to build '%s'", yellowtxt(worker.store.printStorePath(drvPath)))); + worker.waitForAWhile(shared_from_this()); + outputLocks.unlock(); + return; + case rpDecline: + /* We should do it ourselves. */ + break; + } + } + + actLock.reset(); + + state = &DerivationGoal::tryLocalBuild; + worker.wakeUp(shared_from_this()); +} + +void DerivationGoal::tryLocalBuild() { + bool buildLocally = buildMode != bmNormal || parsedDrv->willBuildLocally(worker.store); + + /* Make sure that we are allowed to start a build. If this + derivation prefers to be done locally, do it even if + maxBuildJobs is 0. */ + unsigned int curBuilds = worker.getNrLocalBuilds(); + if (curBuilds >= settings.maxBuildJobs && !(buildLocally && curBuilds == 0)) { + worker.waitForBuildSlot(shared_from_this()); + outputLocks.unlock(); + return; + } + + /* If `build-users-group' is not empty, then we have to build as + one of the members of that group. */ + if (settings.buildUsersGroup != "" && getuid() == 0) { +#if defined(__linux__) || defined(__APPLE__) + if (!buildUser) buildUser = std::make_unique(); + + if (buildUser->findFreeUser()) { + /* Make sure that no other processes are executing under this + uid. */ + buildUser->kill(); + } else { + if (!actLock) + actLock = std::make_unique(*logger, lvlWarn, actBuildWaiting, + fmt("waiting for UID to build '%s'", yellowtxt(worker.store.printStorePath(drvPath)))); + worker.waitForAWhile(shared_from_this()); + return; + } +#else + /* Don't know how to block the creation of setuid/setgid + binaries on this platform. */ + throw Error("build users are not supported on this platform for security reasons"); +#endif + } + + actLock.reset(); + + try { + + /* Okay, we have to build. */ + startBuilder(); + + } catch (BuildError & e) { + outputLocks.unlock(); + buildUser.reset(); + worker.permanentFailure = true; + done(BuildResult::InputRejected, e); + return; + } + + /* This state will be reached when we get EOF on the child's + log pipe. */ + state = &DerivationGoal::buildDone; + + started(); +} + + +static void chmod_(const Path & path, mode_t mode) +{ + if (chmod(path.c_str(), mode) == -1) + throw SysError("setting permissions on '%s'", path); +} + + +/* Move/rename path 'src' to 'dst'. Temporarily make 'src' writable if + it's a directory and we're not root (to be able to update the + directory's parent link ".."). */ +static void movePath(const Path & src, const Path & dst) +{ + auto st = lstat(src); + + bool changePerm = (geteuid() && S_ISDIR(st.st_mode) && !(st.st_mode & S_IWUSR)); + + if (changePerm) + chmod_(src, st.st_mode | S_IWUSR); + + if (rename(src.c_str(), dst.c_str())) + throw SysError("renaming '%1%' to '%2%'", src, dst); + + if (changePerm) + chmod_(dst, st.st_mode); +} + + +void replaceValidPath(const Path & storePath, const Path & tmpPath) +{ + /* We can't atomically replace storePath (the original) with + tmpPath (the replacement), so we have to move it out of the + way first. We'd better not be interrupted here, because if + we're repairing (say) Glibc, we end up with a broken system. */ + Path oldPath = (format("%1%.old-%2%-%3%") % storePath % getpid() % random()).str(); + if (pathExists(storePath)) + movePath(storePath, oldPath); + + try { + movePath(tmpPath, storePath); + } catch (...) { + try { + // attempt to recover + movePath(oldPath, storePath); + } catch (...) { + ignoreException(); + } + throw; + } + + deletePath(oldPath); +} + + +MakeError(NotDeterministic, BuildError); + + +void DerivationGoal::buildDone() +{ + trace("build done"); + + /* Release the build user at the end of this function. We don't do + it right away because we don't want another build grabbing this + uid and then messing around with our output. */ + Finally releaseBuildUser([&]() { buildUser.reset(); }); + + sandboxMountNamespace = -1; + + /* Since we got an EOF on the logger pipe, the builder is presumed + to have terminated. In fact, the builder could also have + simply have closed its end of the pipe, so just to be sure, + kill it. */ + int status = hook ? hook->pid.kill() : pid.kill(); + + debug("builder process for '%s' finished", worker.store.printStorePath(drvPath)); + + result.timesBuilt++; + result.stopTime = time(0); + + /* So the child is gone now. */ + worker.childTerminated(this); + + /* Close the read side of the logger pipe. */ + if (hook) { + hook->builderOut.readSide = -1; + hook->fromHook.readSide = -1; + } else + builderOut.readSide = -1; + + /* Close the log file. */ + closeLogFile(); + + /* When running under a build user, make sure that all processes + running under that uid are gone. This is to prevent a + malicious user from leaving behind a process that keeps files + open and modifies them after they have been chown'ed to + root. */ + if (buildUser) buildUser->kill(); + + /* Terminate the recursive Nix daemon. */ + stopDaemon(); + + bool diskFull = false; + + try { + + /* Check the exit status. */ + if (!statusOk(status)) { + + /* Heuristically check whether the build failure may have + been caused by a disk full condition. We have no way + of knowing whether the build actually got an ENOSPC. + So instead, check if the disk is (nearly) full now. If + so, we don't mark this build as a permanent failure. */ +#if HAVE_STATVFS + uint64_t required = 8ULL * 1024 * 1024; // FIXME: make configurable + struct statvfs st; + if (statvfs(worker.store.realStoreDir.c_str(), &st) == 0 && + (uint64_t) st.f_bavail * st.f_bsize < required) + diskFull = true; + if (statvfs(tmpDir.c_str(), &st) == 0 && + (uint64_t) st.f_bavail * st.f_bsize < required) + diskFull = true; +#endif + + deleteTmpDir(false); + + /* Move paths out of the chroot for easier debugging of + build failures. */ + if (useChroot && buildMode == bmNormal) + for (auto & [_, status] : initialOutputs) { + if (!status.known) continue; + if (buildMode != bmCheck && status.known->isValid()) continue; + auto p = worker.store.printStorePath(status.known->path); + if (pathExists(chrootRootDir + p)) + rename((chrootRootDir + p).c_str(), p.c_str()); + } + + auto msg = fmt("builder for '%s' %s", + yellowtxt(worker.store.printStorePath(drvPath)), + statusToString(status)); + + if (!logger->isVerbose() && !logTail.empty()) { + msg += (format("; last %d log lines:") % logTail.size()).str(); + for (auto & line : logTail) + msg += "\n " + line; + } + + if (diskFull) + msg += "\nnote: build failure may have been caused by lack of free disk space"; + + throw BuildError(msg); + } + + /* Compute the FS closure of the outputs and register them as + being valid. */ + registerOutputs(); + + if (settings.postBuildHook != "") { + Activity act(*logger, lvlInfo, actPostBuildHook, + fmt("running post-build-hook '%s'", settings.postBuildHook), + Logger::Fields{worker.store.printStorePath(drvPath)}); + PushActivity pact(act.id); + StorePathSet outputPaths; + for (auto i : drv->outputs) { + outputPaths.insert(finalOutputs.at(i.first)); + } + std::map hookEnvironment = getEnv(); + + hookEnvironment.emplace("DRV_PATH", worker.store.printStorePath(drvPath)); + hookEnvironment.emplace("OUT_PATHS", chomp(concatStringsSep(" ", worker.store.printStorePathSet(outputPaths)))); + + RunOptions opts(settings.postBuildHook, {}); + opts.environment = hookEnvironment; + + struct LogSink : Sink { + Activity & act; + std::string currentLine; + + LogSink(Activity & act) : act(act) { } + + void operator() (const unsigned char * data, size_t len) override { + for (size_t i = 0; i < len; i++) { + auto c = data[i]; + + if (c == '\n') { + flushLine(); + } else { + currentLine += c; + } + } + } + + void flushLine() { + act.result(resPostBuildLogLine, currentLine); + currentLine.clear(); + } + + ~LogSink() { + if (currentLine != "") { + currentLine += '\n'; + flushLine(); + } + } + }; + LogSink sink(act); + + opts.standardOut = &sink; + opts.mergeStderrToStdout = true; + runProgram2(opts); + } + + if (buildMode == bmCheck) { + deleteTmpDir(true); + done(BuildResult::Built); + return; + } + + /* Delete unused redirected outputs (when doing hash rewriting). */ + for (auto & i : redirectedOutputs) + deletePath(worker.store.Store::toRealPath(i.second)); + + /* Delete the chroot (if we were using one). */ + autoDelChroot.reset(); /* this runs the destructor */ + + deleteTmpDir(true); + + /* Repeat the build if necessary. */ + if (curRound++ < nrRounds) { + outputLocks.unlock(); + state = &DerivationGoal::tryToBuild; + worker.wakeUp(shared_from_this()); + return; + } + + /* It is now safe to delete the lock files, since all future + lockers will see that the output paths are valid; they will + not create new lock files with the same names as the old + (unlinked) lock files. */ + outputLocks.setDeletion(true); + outputLocks.unlock(); + + } catch (BuildError & e) { + outputLocks.unlock(); + + BuildResult::Status st = BuildResult::MiscFailure; + + if (hook && WIFEXITED(status) && WEXITSTATUS(status) == 101) + st = BuildResult::TimedOut; + + else if (hook && (!WIFEXITED(status) || WEXITSTATUS(status) != 100)) { + } + + else { + st = + dynamic_cast(&e) ? BuildResult::NotDeterministic : + statusOk(status) ? BuildResult::OutputRejected : + derivationIsImpure(derivationType) || diskFull ? BuildResult::TransientFailure : + BuildResult::PermanentFailure; + } + + done(st, e); + return; + } + + done(BuildResult::Built); +} + +void DerivationGoal::resolvedFinished() { + done(BuildResult::Built); +} + +HookReply DerivationGoal::tryBuildHook() +{ + if (!worker.tryBuildHook || !useDerivation) return rpDecline; + + if (!worker.hook) + worker.hook = std::make_unique(); + + try { + + /* Send the request to the hook. */ + worker.hook->sink + << "try" + << (worker.getNrLocalBuilds() < settings.maxBuildJobs ? 1 : 0) + << drv->platform + << worker.store.printStorePath(drvPath) + << parsedDrv->getRequiredSystemFeatures(); + worker.hook->sink.flush(); + + /* Read the first line of input, which should be a word indicating + whether the hook wishes to perform the build. */ + string reply; + while (true) { + string s = readLine(worker.hook->fromHook.readSide.get()); + if (handleJSONLogMessage(s, worker.act, worker.hook->activities, true)) + ; + else if (string(s, 0, 2) == "# ") { + reply = string(s, 2); + break; + } + else { + s += "\n"; + writeToStderr(s); + } + } + + debug("hook reply is '%1%'", reply); + + if (reply == "decline") + return rpDecline; + else if (reply == "decline-permanently") { + worker.tryBuildHook = false; + worker.hook = 0; + return rpDecline; + } + else if (reply == "postpone") + return rpPostpone; + else if (reply != "accept") + throw Error("bad hook reply '%s'", reply); + + } catch (SysError & e) { + if (e.errNo == EPIPE) { + logError({ + .name = "Build hook died", + .hint = hintfmt( + "build hook died unexpectedly: %s", + chomp(drainFD(worker.hook->fromHook.readSide.get()))) + }); + worker.hook = 0; + return rpDecline; + } else + throw; + } + + hook = std::move(worker.hook); + + machineName = readLine(hook->fromHook.readSide.get()); + + /* Tell the hook all the inputs that have to be copied to the + remote system. */ + worker_proto::write(worker.store, hook->sink, inputPaths); + + /* Tell the hooks the missing outputs that have to be copied back + from the remote system. */ + { + StorePathSet missingPaths; + for (auto & [_, status] : initialOutputs) { + if (!status.known) continue; + if (buildMode != bmCheck && status.known->isValid()) continue; + missingPaths.insert(status.known->path); + } + worker_proto::write(worker.store, hook->sink, missingPaths); + } + + hook->sink = FdSink(); + hook->toHook.writeSide = -1; + + /* Create the log file and pipe. */ + Path logFile = openLogFile(); + + set fds; + fds.insert(hook->fromHook.readSide.get()); + fds.insert(hook->builderOut.readSide.get()); + worker.childStarted(shared_from_this(), fds, false, false); + + return rpAccept; +} + + +int childEntry(void * arg) +{ + ((DerivationGoal *) arg)->runChild(); + return 1; +} + + +StorePathSet DerivationGoal::exportReferences(const StorePathSet & storePaths) +{ + StorePathSet paths; + + for (auto & storePath : storePaths) { + if (!inputPaths.count(storePath)) + throw BuildError("cannot export references of path '%s' because it is not in the input closure of the derivation", worker.store.printStorePath(storePath)); + + worker.store.computeFSClosure({storePath}, paths); + } + + /* If there are derivations in the graph, then include their + outputs as well. This is useful if you want to do things + like passing all build-time dependencies of some path to a + derivation that builds a NixOS DVD image. */ + auto paths2 = paths; + + for (auto & j : paths2) { + if (j.isDerivation()) { + Derivation drv = worker.store.derivationFromPath(j); + for (auto & k : drv.outputsAndOptPaths(worker.store)) { + if (!k.second.second) + /* FIXME: I am confused why we are calling + `computeFSClosure` on the output path, rather than + derivation itself. That doesn't seem right to me, so I + won't try to implemented this for CA derivations. */ + throw UnimplementedError("exportReferences on CA derivations is not yet implemented"); + worker.store.computeFSClosure(*k.second.second, paths); + } + } + } + + return paths; +} + +static std::once_flag dns_resolve_flag; + +static void preloadNSS() { + /* builtin:fetchurl can trigger a DNS lookup, which with glibc can trigger a dynamic library load of + one of the glibc NSS libraries in a sandboxed child, which will fail unless the library's already + been loaded in the parent. So we force a lookup of an invalid domain to force the NSS machinery to + load its lookup libraries in the parent before any child gets a chance to. */ + std::call_once(dns_resolve_flag, []() { + struct addrinfo *res = NULL; + + if (getaddrinfo("this.pre-initializes.the.dns.resolvers.invalid.", "http", NULL, &res) != 0) { + if (res) freeaddrinfo(res); + } + }); +} + + +void linkOrCopy(const Path & from, const Path & to) +{ + if (link(from.c_str(), to.c_str()) == -1) { + /* Hard-linking fails if we exceed the maximum link count on a + file (e.g. 32000 of ext3), which is quite possible after a + 'nix-store --optimise'. FIXME: actually, why don't we just + bind-mount in this case? + + It can also fail with EPERM in BeegFS v7 and earlier versions + which don't allow hard-links to other directories */ + if (errno != EMLINK && errno != EPERM) + throw SysError("linking '%s' to '%s'", to, from); + copyPath(from, to); + } +} + + +void DerivationGoal::startBuilder() +{ + /* Right platform? */ + if (!parsedDrv->canBuildLocally(worker.store)) + throw Error("a '%s' with features {%s} is required to build '%s', but I am a '%s' with features {%s}", + drv->platform, + concatStringsSep(", ", parsedDrv->getRequiredSystemFeatures()), + worker.store.printStorePath(drvPath), + settings.thisSystem, + concatStringsSep(", ", worker.store.systemFeatures)); + + if (drv->isBuiltin()) + preloadNSS(); + +#if __APPLE__ + additionalSandboxProfile = parsedDrv->getStringAttr("__sandboxProfile").value_or(""); +#endif + + /* Are we doing a chroot build? */ + { + auto noChroot = parsedDrv->getBoolAttr("__noChroot"); + if (settings.sandboxMode == smEnabled) { + if (noChroot) + throw Error("derivation '%s' has '__noChroot' set, " + "but that's not allowed when 'sandbox' is 'true'", worker.store.printStorePath(drvPath)); +#if __APPLE__ + if (additionalSandboxProfile != "") + throw Error("derivation '%s' specifies a sandbox profile, " + "but this is only allowed when 'sandbox' is 'relaxed'", worker.store.printStorePath(drvPath)); +#endif + useChroot = true; + } + else if (settings.sandboxMode == smDisabled) + useChroot = false; + else if (settings.sandboxMode == smRelaxed) + useChroot = !(derivationIsImpure(derivationType)) && !noChroot; + } + + if (worker.store.storeDir != worker.store.realStoreDir) { + #if __linux__ + useChroot = true; + #else + throw Error("building using a diverted store is not supported on this platform"); + #endif + } + + /* Create a temporary directory where the build will take + place. */ + tmpDir = createTempDir("", "nix-build-" + std::string(drvPath.name()), false, false, 0700); + + chownToBuilder(tmpDir); + + for (auto & [outputName, status] : initialOutputs) { + /* Set scratch path we'll actually use during the build. + + If we're not doing a chroot build, but we have some valid + output paths. Since we can't just overwrite or delete + them, we have to do hash rewriting: i.e. in the + environment/arguments passed to the build, we replace the + hashes of the valid outputs with unique dummy strings; + after the build, we discard the redirected outputs + corresponding to the valid outputs, and rewrite the + contents of the new outputs to replace the dummy strings + with the actual hashes. */ + auto scratchPath = + !status.known + ? makeFallbackPath(outputName) + : !needsHashRewrite() + /* Can always use original path in sandbox */ + ? status.known->path + : !status.known->isPresent() + /* If path doesn't yet exist can just use it */ + ? status.known->path + : buildMode != bmRepair && !status.known->isValid() + /* If we aren't repairing we'll delete a corrupted path, so we + can use original path */ + ? status.known->path + : /* If we are repairing or the path is totally valid, we'll need + to use a temporary path */ + makeFallbackPath(status.known->path); + scratchOutputs.insert_or_assign(outputName, scratchPath); + + /* A non-removed corrupted path needs to be stored here, too */ + if (buildMode == bmRepair && !status.known->isValid()) + redirectedBadOutputs.insert(status.known->path); + + /* Substitute output placeholders with the scratch output paths. + We'll use during the build. */ + inputRewrites[hashPlaceholder(outputName)] = worker.store.printStorePath(scratchPath); + + /* Additional tasks if we know the final path a priori. */ + if (!status.known) continue; + auto fixedFinalPath = status.known->path; + + /* Additional tasks if the final and scratch are both known and + differ. */ + if (fixedFinalPath == scratchPath) continue; + + /* Ensure scratch path is ours to use. */ + deletePath(worker.store.printStorePath(scratchPath)); + + /* Rewrite and unrewrite paths */ + { + std::string h1 { fixedFinalPath.hashPart() }; + std::string h2 { scratchPath.hashPart() }; + inputRewrites[h1] = h2; + } + + redirectedOutputs.insert_or_assign(std::move(fixedFinalPath), std::move(scratchPath)); + } + + /* Construct the environment passed to the builder. */ + initEnv(); + + writeStructuredAttrs(); + + /* Handle exportReferencesGraph(), if set. */ + if (!parsedDrv->getStructuredAttrs()) { + /* The `exportReferencesGraph' feature allows the references graph + to be passed to a builder. This attribute should be a list of + pairs [name1 path1 name2 path2 ...]. The references graph of + each `pathN' will be stored in a text file `nameN' in the + temporary build directory. The text files have the format used + by `nix-store --register-validity'. However, the deriver + fields are left empty. */ + string s = get(drv->env, "exportReferencesGraph").value_or(""); + Strings ss = tokenizeString(s); + if (ss.size() % 2 != 0) + throw BuildError("odd number of tokens in 'exportReferencesGraph': '%1%'", s); + for (Strings::iterator i = ss.begin(); i != ss.end(); ) { + string fileName = *i++; + static std::regex regex("[A-Za-z_][A-Za-z0-9_.-]*"); + if (!std::regex_match(fileName, regex)) + throw Error("invalid file name '%s' in 'exportReferencesGraph'", fileName); + + auto storePathS = *i++; + if (!worker.store.isInStore(storePathS)) + throw BuildError("'exportReferencesGraph' contains a non-store path '%1%'", storePathS); + auto storePath = worker.store.toStorePath(storePathS).first; + + /* Write closure info to . */ + writeFile(tmpDir + "/" + fileName, + worker.store.makeValidityRegistration( + exportReferences({storePath}), false, false)); + } + } + + if (useChroot) { + + /* Allow a user-configurable set of directories from the + host file system. */ + PathSet dirs = settings.sandboxPaths; + PathSet dirs2 = settings.extraSandboxPaths; + dirs.insert(dirs2.begin(), dirs2.end()); + + dirsInChroot.clear(); + + for (auto i : dirs) { + if (i.empty()) continue; + bool optional = false; + if (i[i.size() - 1] == '?') { + optional = true; + i.pop_back(); + } + size_t p = i.find('='); + if (p == string::npos) + dirsInChroot[i] = {i, optional}; + else + dirsInChroot[string(i, 0, p)] = {string(i, p + 1), optional}; + } + dirsInChroot[tmpDirInSandbox] = tmpDir; + + /* Add the closure of store paths to the chroot. */ + StorePathSet closure; + for (auto & i : dirsInChroot) + try { + if (worker.store.isInStore(i.second.source)) + worker.store.computeFSClosure(worker.store.toStorePath(i.second.source).first, closure); + } catch (InvalidPath & e) { + } catch (Error & e) { + e.addTrace({}, "while processing 'sandbox-paths'"); + throw; + } + for (auto & i : closure) { + auto p = worker.store.printStorePath(i); + dirsInChroot.insert_or_assign(p, p); + } + + PathSet allowedPaths = settings.allowedImpureHostPrefixes; + + /* This works like the above, except on a per-derivation level */ + auto impurePaths = parsedDrv->getStringsAttr("__impureHostDeps").value_or(Strings()); + + for (auto & i : impurePaths) { + bool found = false; + /* Note: we're not resolving symlinks here to prevent + giving a non-root user info about inaccessible + files. */ + Path canonI = canonPath(i); + /* If only we had a trie to do this more efficiently :) luckily, these are generally going to be pretty small */ + for (auto & a : allowedPaths) { + Path canonA = canonPath(a); + if (canonI == canonA || isInDir(canonI, canonA)) { + found = true; + break; + } + } + if (!found) + throw Error("derivation '%s' requested impure path '%s', but it was not in allowed-impure-host-deps", + worker.store.printStorePath(drvPath), i); + + dirsInChroot[i] = i; + } + +#if __linux__ + /* Create a temporary directory in which we set up the chroot + environment using bind-mounts. We put it in the Nix store + to ensure that we can create hard-links to non-directory + inputs in the fake Nix store in the chroot (see below). */ + chrootRootDir = worker.store.Store::toRealPath(drvPath) + ".chroot"; + deletePath(chrootRootDir); + + /* Clean up the chroot directory automatically. */ + autoDelChroot = std::make_shared(chrootRootDir); + + printMsg(lvlChatty, format("setting up chroot environment in '%1%'") % chrootRootDir); + + if (mkdir(chrootRootDir.c_str(), 0750) == -1) + throw SysError("cannot create '%1%'", chrootRootDir); + + if (buildUser && chown(chrootRootDir.c_str(), 0, buildUser->getGID()) == -1) + throw SysError("cannot change ownership of '%1%'", chrootRootDir); + + /* Create a writable /tmp in the chroot. Many builders need + this. (Of course they should really respect $TMPDIR + instead.) */ + Path chrootTmpDir = chrootRootDir + "/tmp"; + createDirs(chrootTmpDir); + chmod_(chrootTmpDir, 01777); + + /* Create a /etc/passwd with entries for the build user and the + nobody account. The latter is kind of a hack to support + Samba-in-QEMU. */ + createDirs(chrootRootDir + "/etc"); + + writeFile(chrootRootDir + "/etc/passwd", fmt( + "root:x:0:0:Nix build user:%3%:/noshell\n" + "nixbld:x:%1%:%2%:Nix build user:%3%:/noshell\n" + "nobody:x:65534:65534:Nobody:/:/noshell\n", + sandboxUid(), sandboxGid(), settings.sandboxBuildDir)); + + /* Declare the build user's group so that programs get a consistent + view of the system (e.g., "id -gn"). */ + writeFile(chrootRootDir + "/etc/group", + fmt("root:x:0:\n" + "nixbld:!:%1%:\n" + "nogroup:x:65534:\n", sandboxGid())); + + /* Create /etc/hosts with localhost entry. */ + if (!(derivationIsImpure(derivationType))) + writeFile(chrootRootDir + "/etc/hosts", "127.0.0.1 localhost\n::1 localhost\n"); + + /* Make the closure of the inputs available in the chroot, + rather than the whole Nix store. This prevents any access + to undeclared dependencies. Directories are bind-mounted, + while other inputs are hard-linked (since only directories + can be bind-mounted). !!! As an extra security + precaution, make the fake Nix store only writable by the + build user. */ + Path chrootStoreDir = chrootRootDir + worker.store.storeDir; + createDirs(chrootStoreDir); + chmod_(chrootStoreDir, 01775); + + if (buildUser && chown(chrootStoreDir.c_str(), 0, buildUser->getGID()) == -1) + throw SysError("cannot change ownership of '%1%'", chrootStoreDir); + + for (auto & i : inputPaths) { + auto p = worker.store.printStorePath(i); + Path r = worker.store.toRealPath(p); + if (S_ISDIR(lstat(r).st_mode)) + dirsInChroot.insert_or_assign(p, r); + else + linkOrCopy(r, chrootRootDir + p); + } + + /* If we're repairing, checking or rebuilding part of a + multiple-outputs derivation, it's possible that we're + rebuilding a path that is in settings.dirsInChroot + (typically the dependencies of /bin/sh). Throw them + out. */ + for (auto & i : drv->outputsAndOptPaths(worker.store)) { + /* If the name isn't known a priori (i.e. floating + content-addressed derivation), the temporary location we use + should be fresh. Freshness means it is impossible that the path + is already in the sandbox, so we don't need to worry about + removing it. */ + if (i.second.second) + dirsInChroot.erase(worker.store.printStorePath(*i.second.second)); + } + +#elif __APPLE__ + /* We don't really have any parent prep work to do (yet?) + All work happens in the child, instead. */ +#else + throw Error("sandboxing builds is not supported on this platform"); +#endif + } + + if (needsHashRewrite() && pathExists(homeDir)) + throw Error("home directory '%1%' exists; please remove it to assure purity of builds without sandboxing", homeDir); + + if (useChroot && settings.preBuildHook != "" && dynamic_cast(drv.get())) { + printMsg(lvlChatty, format("executing pre-build hook '%1%'") + % settings.preBuildHook); + auto args = useChroot ? Strings({worker.store.printStorePath(drvPath), chrootRootDir}) : + Strings({ worker.store.printStorePath(drvPath) }); + enum BuildHookState { + stBegin, + stExtraChrootDirs + }; + auto state = stBegin; + auto lines = runProgram(settings.preBuildHook, false, args); + auto lastPos = std::string::size_type{0}; + for (auto nlPos = lines.find('\n'); nlPos != string::npos; + nlPos = lines.find('\n', lastPos)) { + auto line = std::string{lines, lastPos, nlPos - lastPos}; + lastPos = nlPos + 1; + if (state == stBegin) { + if (line == "extra-sandbox-paths" || line == "extra-chroot-dirs") { + state = stExtraChrootDirs; + } else { + throw Error("unknown pre-build hook command '%1%'", line); + } + } else if (state == stExtraChrootDirs) { + if (line == "") { + state = stBegin; + } else { + auto p = line.find('='); + if (p == string::npos) + dirsInChroot[line] = line; + else + dirsInChroot[string(line, 0, p)] = string(line, p + 1); + } + } + } + } + + /* Fire up a Nix daemon to process recursive Nix calls from the + builder. */ + if (parsedDrv->getRequiredSystemFeatures().count("recursive-nix")) + startDaemon(); + + /* Run the builder. */ + printMsg(lvlChatty, "executing builder '%1%'", drv->builder); + + /* Create the log file. */ + Path logFile = openLogFile(); + + /* Create a pipe to get the output of the builder. */ + //builderOut.create(); + + builderOut.readSide = posix_openpt(O_RDWR | O_NOCTTY); + if (!builderOut.readSide) + throw SysError("opening pseudoterminal master"); + + std::string slaveName(ptsname(builderOut.readSide.get())); + + if (buildUser) { + if (chmod(slaveName.c_str(), 0600)) + throw SysError("changing mode of pseudoterminal slave"); + + if (chown(slaveName.c_str(), buildUser->getUID(), 0)) + throw SysError("changing owner of pseudoterminal slave"); + } +#if __APPLE__ + else { + if (grantpt(builderOut.readSide.get())) + throw SysError("granting access to pseudoterminal slave"); + } +#endif + + #if 0 + // Mount the pt in the sandbox so that the "tty" command works. + // FIXME: this doesn't work with the new devpts in the sandbox. + if (useChroot) + dirsInChroot[slaveName] = {slaveName, false}; + #endif + + if (unlockpt(builderOut.readSide.get())) + throw SysError("unlocking pseudoterminal"); + + builderOut.writeSide = open(slaveName.c_str(), O_RDWR | O_NOCTTY); + if (!builderOut.writeSide) + throw SysError("opening pseudoterminal slave"); + + // Put the pt into raw mode to prevent \n -> \r\n translation. + struct termios term; + if (tcgetattr(builderOut.writeSide.get(), &term)) + throw SysError("getting pseudoterminal attributes"); + + cfmakeraw(&term); + + if (tcsetattr(builderOut.writeSide.get(), TCSANOW, &term)) + throw SysError("putting pseudoterminal into raw mode"); + + result.startTime = time(0); + + /* Fork a child to build the package. */ + ProcessOptions options; + +#if __linux__ + if (useChroot) { + /* Set up private namespaces for the build: + + - The PID namespace causes the build to start as PID 1. + Processes outside of the chroot are not visible to those + on the inside, but processes inside the chroot are + visible from the outside (though with different PIDs). + + - The private mount namespace ensures that all the bind + mounts we do will only show up in this process and its + children, and will disappear automatically when we're + done. + + - The private network namespace ensures that the builder + cannot talk to the outside world (or vice versa). It + only has a private loopback interface. (Fixed-output + derivations are not run in a private network namespace + to allow functions like fetchurl to work.) + + - The IPC namespace prevents the builder from communicating + with outside processes using SysV IPC mechanisms (shared + memory, message queues, semaphores). It also ensures + that all IPC objects are destroyed when the builder + exits. + + - The UTS namespace ensures that builders see a hostname of + localhost rather than the actual hostname. + + We use a helper process to do the clone() to work around + clone() being broken in multi-threaded programs due to + at-fork handlers not being run. Note that we use + CLONE_PARENT to ensure that the real builder is parented to + us. + */ + + if (!(derivationIsImpure(derivationType))) + privateNetwork = true; + + userNamespaceSync.create(); + + options.allowVfork = false; + + Path maxUserNamespaces = "/proc/sys/user/max_user_namespaces"; + static bool userNamespacesEnabled = + pathExists(maxUserNamespaces) + && trim(readFile(maxUserNamespaces)) != "0"; + + usingUserNamespace = userNamespacesEnabled; + + Pid helper = startProcess([&]() { + + /* Drop additional groups here because we can't do it + after we've created the new user namespace. FIXME: + this means that if we're not root in the parent + namespace, we can't drop additional groups; they will + be mapped to nogroup in the child namespace. There does + not seem to be a workaround for this. (But who can tell + from reading user_namespaces(7)?) + See also https://lwn.net/Articles/621612/. */ + if (getuid() == 0 && setgroups(0, 0) == -1) + throw SysError("setgroups failed"); + + size_t stackSize = 1 * 1024 * 1024; + char * stack = (char *) mmap(0, stackSize, + PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); + if (stack == MAP_FAILED) throw SysError("allocating stack"); + + int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | CLONE_PARENT | SIGCHLD; + if (privateNetwork) + flags |= CLONE_NEWNET; + if (usingUserNamespace) + flags |= CLONE_NEWUSER; + + pid_t child = clone(childEntry, stack + stackSize, flags, this); + if (child == -1 && errno == EINVAL) { + /* Fallback for Linux < 2.13 where CLONE_NEWPID and + CLONE_PARENT are not allowed together. */ + flags &= ~CLONE_NEWPID; + child = clone(childEntry, stack + stackSize, flags, this); + } + if (usingUserNamespace && child == -1 && (errno == EPERM || errno == EINVAL)) { + /* Some distros patch Linux to not allow unprivileged + * user namespaces. If we get EPERM or EINVAL, try + * without CLONE_NEWUSER and see if that works. + */ + usingUserNamespace = false; + flags &= ~CLONE_NEWUSER; + child = clone(childEntry, stack + stackSize, flags, this); + } + /* Otherwise exit with EPERM so we can handle this in the + parent. This is only done when sandbox-fallback is set + to true (the default). */ + if (child == -1 && (errno == EPERM || errno == EINVAL) && settings.sandboxFallback) + _exit(1); + if (child == -1) throw SysError("cloning builder process"); + + writeFull(builderOut.writeSide.get(), + fmt("%d %d\n", usingUserNamespace, child)); + _exit(0); + }, options); + + int res = helper.wait(); + if (res != 0 && settings.sandboxFallback) { + useChroot = false; + initTmpDir(); + goto fallback; + } else if (res != 0) + throw Error("unable to start build process"); + + userNamespaceSync.readSide = -1; + + /* Close the write side to prevent runChild() from hanging + reading from this. */ + Finally cleanup([&]() { + userNamespaceSync.writeSide = -1; + }); + + pid_t tmp; + auto ss = tokenizeString>(readLine(builderOut.readSide.get())); + assert(ss.size() == 2); + usingUserNamespace = ss[0] == "1"; + if (!string2Int(ss[1], tmp)) abort(); + pid = tmp; + + if (usingUserNamespace) { + /* Set the UID/GID mapping of the builder's user namespace + such that the sandbox user maps to the build user, or to + the calling user (if build users are disabled). */ + uid_t hostUid = buildUser ? buildUser->getUID() : getuid(); + uid_t hostGid = buildUser ? buildUser->getGID() : getgid(); + + writeFile("/proc/" + std::to_string(pid) + "/uid_map", + fmt("%d %d 1", sandboxUid(), hostUid)); + + writeFile("/proc/" + std::to_string(pid) + "/setgroups", "deny"); + + writeFile("/proc/" + std::to_string(pid) + "/gid_map", + fmt("%d %d 1", sandboxGid(), hostGid)); + } else { + debug("note: not using a user namespace"); + if (!buildUser) + throw Error("cannot perform a sandboxed build because user namespaces are not enabled; check /proc/sys/user/max_user_namespaces"); + } + + /* Save the mount namespace of the child. We have to do this + *before* the child does a chroot. */ + sandboxMountNamespace = open(fmt("/proc/%d/ns/mnt", (pid_t) pid).c_str(), O_RDONLY); + if (sandboxMountNamespace.get() == -1) + throw SysError("getting sandbox mount namespace"); + + /* Signal the builder that we've updated its user namespace. */ + writeFull(userNamespaceSync.writeSide.get(), "1"); + + } else +#endif + { + fallback: + options.allowVfork = !buildUser && !drv->isBuiltin(); + pid = startProcess([&]() { + runChild(); + }, options); + } + + /* parent */ + pid.setSeparatePG(true); + builderOut.writeSide = -1; + worker.childStarted(shared_from_this(), {builderOut.readSide.get()}, true, true); + + /* Check if setting up the build environment failed. */ + while (true) { + string msg = readLine(builderOut.readSide.get()); + if (string(msg, 0, 1) == "\2") break; + if (string(msg, 0, 1) == "\1") { + FdSource source(builderOut.readSide.get()); + auto ex = readError(source); + ex.addTrace({}, "while setting up the build environment"); + throw ex; + } + debug("sandbox setup: " + msg); + } +} + + +void DerivationGoal::initTmpDir() { + /* In a sandbox, for determinism, always use the same temporary + directory. */ +#if __linux__ + tmpDirInSandbox = useChroot ? settings.sandboxBuildDir : tmpDir; +#else + tmpDirInSandbox = tmpDir; +#endif + + /* In non-structured mode, add all bindings specified in the + derivation via the environment, except those listed in the + passAsFile attribute. Those are passed as file names pointing + to temporary files containing the contents. Note that + passAsFile is ignored in structure mode because it's not + needed (attributes are not passed through the environment, so + there is no size constraint). */ + if (!parsedDrv->getStructuredAttrs()) { + + StringSet passAsFile = tokenizeString(get(drv->env, "passAsFile").value_or("")); + for (auto & i : drv->env) { + if (passAsFile.find(i.first) == passAsFile.end()) { + env[i.first] = i.second; + } else { + auto hash = hashString(htSHA256, i.first); + string fn = ".attr-" + hash.to_string(Base32, false); + Path p = tmpDir + "/" + fn; + writeFile(p, rewriteStrings(i.second, inputRewrites)); + chownToBuilder(p); + env[i.first + "Path"] = tmpDirInSandbox + "/" + fn; + } + } + + } + + /* For convenience, set an environment pointing to the top build + directory. */ + env["NIX_BUILD_TOP"] = tmpDirInSandbox; + + /* Also set TMPDIR and variants to point to this directory. */ + env["TMPDIR"] = env["TEMPDIR"] = env["TMP"] = env["TEMP"] = tmpDirInSandbox; + + /* Explicitly set PWD to prevent problems with chroot builds. In + particular, dietlibc cannot figure out the cwd because the + inode of the current directory doesn't appear in .. (because + getdents returns the inode of the mount point). */ + env["PWD"] = tmpDirInSandbox; +} + + +void DerivationGoal::initEnv() +{ + env.clear(); + + /* Most shells initialise PATH to some default (/bin:/usr/bin:...) when + PATH is not set. We don't want this, so we fill it in with some dummy + value. */ + env["PATH"] = "/path-not-set"; + + /* Set HOME to a non-existing path to prevent certain programs from using + /etc/passwd (or NIS, or whatever) to locate the home directory (for + example, wget looks for ~/.wgetrc). I.e., these tools use /etc/passwd + if HOME is not set, but they will just assume that the settings file + they are looking for does not exist if HOME is set but points to some + non-existing path. */ + env["HOME"] = homeDir; + + /* Tell the builder where the Nix store is. Usually they + shouldn't care, but this is useful for purity checking (e.g., + the compiler or linker might only want to accept paths to files + in the store or in the build directory). */ + env["NIX_STORE"] = worker.store.storeDir; + + /* The maximum number of cores to utilize for parallel building. */ + env["NIX_BUILD_CORES"] = (format("%d") % settings.buildCores).str(); + + initTmpDir(); + + /* Compatibility hack with Nix <= 0.7: if this is a fixed-output + derivation, tell the builder, so that for instance `fetchurl' + can skip checking the output. On older Nixes, this environment + variable won't be set, so `fetchurl' will do the check. */ + if (derivationIsFixed(derivationType)) env["NIX_OUTPUT_CHECKED"] = "1"; + + /* *Only* if this is a fixed-output derivation, propagate the + values of the environment variables specified in the + `impureEnvVars' attribute to the builder. This allows for + instance environment variables for proxy configuration such as + `http_proxy' to be easily passed to downloaders like + `fetchurl'. Passing such environment variables from the caller + to the builder is generally impure, but the output of + fixed-output derivations is by definition pure (since we + already know the cryptographic hash of the output). */ + if (derivationIsImpure(derivationType)) { + for (auto & i : parsedDrv->getStringsAttr("impureEnvVars").value_or(Strings())) + env[i] = getEnv(i).value_or(""); + } + + /* Currently structured log messages piggyback on stderr, but we + may change that in the future. So tell the builder which file + descriptor to use for that. */ + env["NIX_LOG_FD"] = "2"; + + /* Trigger colored output in various tools. */ + env["TERM"] = "xterm-256color"; +} + + +static std::regex shVarName("[A-Za-z_][A-Za-z0-9_]*"); + + +void DerivationGoal::writeStructuredAttrs() +{ + auto structuredAttrs = parsedDrv->getStructuredAttrs(); + if (!structuredAttrs) return; + + auto json = *structuredAttrs; + + /* Add an "outputs" object containing the output paths. */ + nlohmann::json outputs; + for (auto & i : drv->outputs) { + /* The placeholder must have a rewrite, so we use it to cover both the + cases where we know or don't know the output path ahead of time. */ + outputs[i.first] = rewriteStrings(hashPlaceholder(i.first), inputRewrites); + } + json["outputs"] = outputs; + + /* Handle exportReferencesGraph. */ + auto e = json.find("exportReferencesGraph"); + if (e != json.end() && e->is_object()) { + for (auto i = e->begin(); i != e->end(); ++i) { + std::ostringstream str; + { + JSONPlaceholder jsonRoot(str, true); + StorePathSet storePaths; + for (auto & p : *i) + storePaths.insert(worker.store.parseStorePath(p.get())); + worker.store.pathInfoToJSON(jsonRoot, + exportReferences(storePaths), false, true); + } + json[i.key()] = nlohmann::json::parse(str.str()); // urgh + } + } + + writeFile(tmpDir + "/.attrs.json", rewriteStrings(json.dump(), inputRewrites)); + chownToBuilder(tmpDir + "/.attrs.json"); + + /* As a convenience to bash scripts, write a shell file that + maps all attributes that are representable in bash - + namely, strings, integers, nulls, Booleans, and arrays and + objects consisting entirely of those values. (So nested + arrays or objects are not supported.) */ + + auto handleSimpleType = [](const nlohmann::json & value) -> std::optional { + if (value.is_string()) + return shellEscape(value); + + if (value.is_number()) { + auto f = value.get(); + if (std::ceil(f) == f) + return std::to_string(value.get()); + } + + if (value.is_null()) + return std::string("''"); + + if (value.is_boolean()) + return value.get() ? std::string("1") : std::string(""); + + return {}; + }; + + std::string jsonSh; + + for (auto i = json.begin(); i != json.end(); ++i) { + + if (!std::regex_match(i.key(), shVarName)) continue; + + auto & value = i.value(); + + auto s = handleSimpleType(value); + if (s) + jsonSh += fmt("declare %s=%s\n", i.key(), *s); + + else if (value.is_array()) { + std::string s2; + bool good = true; + + for (auto i = value.begin(); i != value.end(); ++i) { + auto s3 = handleSimpleType(i.value()); + if (!s3) { good = false; break; } + s2 += *s3; s2 += ' '; + } + + if (good) + jsonSh += fmt("declare -a %s=(%s)\n", i.key(), s2); + } + + else if (value.is_object()) { + std::string s2; + bool good = true; + + for (auto i = value.begin(); i != value.end(); ++i) { + auto s3 = handleSimpleType(i.value()); + if (!s3) { good = false; break; } + s2 += fmt("[%s]=%s ", shellEscape(i.key()), *s3); + } + + if (good) + jsonSh += fmt("declare -A %s=(%s)\n", i.key(), s2); + } + } + + writeFile(tmpDir + "/.attrs.sh", rewriteStrings(jsonSh, inputRewrites)); + chownToBuilder(tmpDir + "/.attrs.sh"); +} + +struct RestrictedStoreConfig : LocalFSStoreConfig +{ + using LocalFSStoreConfig::LocalFSStoreConfig; + const std::string name() { return "Restricted Store"; } +}; + +/* A wrapper around LocalStore that only allows building/querying of + paths that are in the input closures of the build or were added via + recursive Nix calls. */ +struct RestrictedStore : public LocalFSStore, public virtual RestrictedStoreConfig +{ + ref next; + + DerivationGoal & goal; + + RestrictedStore(const Params & params, ref next, DerivationGoal & goal) + : StoreConfig(params), Store(params), LocalFSStore(params), next(next), goal(goal) + { } + + Path getRealStoreDir() override + { return next->realStoreDir; } + + std::string getUri() override + { return next->getUri(); } + + StorePathSet queryAllValidPaths() override + { + StorePathSet paths; + for (auto & p : goal.inputPaths) paths.insert(p); + for (auto & p : goal.addedPaths) paths.insert(p); + return paths; + } + + void queryPathInfoUncached(const StorePath & path, + Callback> callback) noexcept override + { + if (goal.isAllowed(path)) { + try { + /* Censor impure information. */ + auto info = std::make_shared(*next->queryPathInfo(path)); + info->deriver.reset(); + info->registrationTime = 0; + info->ultimate = false; + info->sigs.clear(); + callback(info); + } catch (InvalidPath &) { + callback(nullptr); + } + } else + callback(nullptr); + }; + + void queryReferrers(const StorePath & path, StorePathSet & referrers) override + { } + + std::map> queryPartialDerivationOutputMap(const StorePath & path) override + { + if (!goal.isAllowed(path)) + throw InvalidPath("cannot query output map for unknown path '%s' in recursive Nix", printStorePath(path)); + return next->queryPartialDerivationOutputMap(path); + } + + std::optional queryPathFromHashPart(const std::string & hashPart) override + { throw Error("queryPathFromHashPart"); } + + StorePath addToStore(const string & name, const Path & srcPath, + FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, + PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) override + { throw Error("addToStore"); } + + void addToStore(const ValidPathInfo & info, Source & narSource, + RepairFlag repair = NoRepair, CheckSigsFlag checkSigs = CheckSigs) override + { + next->addToStore(info, narSource, repair, checkSigs); + goal.addDependency(info.path); + } + + StorePath addTextToStore(const string & name, const string & s, + const StorePathSet & references, RepairFlag repair = NoRepair) override + { + auto path = next->addTextToStore(name, s, references, repair); + goal.addDependency(path); + return path; + } + + void narFromPath(const StorePath & path, Sink & sink) override + { + if (!goal.isAllowed(path)) + throw InvalidPath("cannot dump unknown path '%s' in recursive Nix", printStorePath(path)); + LocalFSStore::narFromPath(path, sink); + } + + void ensurePath(const StorePath & path) override + { + if (!goal.isAllowed(path)) + throw InvalidPath("cannot substitute unknown path '%s' in recursive Nix", printStorePath(path)); + /* Nothing to be done; 'path' must already be valid. */ + } + + void buildPaths(const std::vector & paths, BuildMode buildMode) override + { + if (buildMode != bmNormal) throw Error("unsupported build mode"); + + StorePathSet newPaths; + + for (auto & path : paths) { + if (!goal.isAllowed(path.path)) + throw InvalidPath("cannot build unknown path '%s' in recursive Nix", printStorePath(path.path)); + } + + next->buildPaths(paths, buildMode); + + for (auto & path : paths) { + if (!path.path.isDerivation()) continue; + auto outputs = next->queryDerivationOutputMap(path.path); + for (auto & output : outputs) + if (wantOutput(output.first, path.outputs)) + newPaths.insert(output.second); + } + + StorePathSet closure; + next->computeFSClosure(newPaths, closure); + for (auto & path : closure) + goal.addDependency(path); + } + + BuildResult buildDerivation(const StorePath & drvPath, const BasicDerivation & drv, + BuildMode buildMode = bmNormal) override + { unsupported("buildDerivation"); } + + void addTempRoot(const StorePath & path) override + { } + + void addIndirectRoot(const Path & path) override + { } + + Roots findRoots(bool censor) override + { return Roots(); } + + void collectGarbage(const GCOptions & options, GCResults & results) override + { } + + void addSignatures(const StorePath & storePath, const StringSet & sigs) override + { unsupported("addSignatures"); } + + void queryMissing(const std::vector & targets, + StorePathSet & willBuild, StorePathSet & willSubstitute, StorePathSet & unknown, + uint64_t & downloadSize, uint64_t & narSize) override + { + /* This is slightly impure since it leaks information to the + client about what paths will be built/substituted or are + already present. Probably not a big deal. */ + + std::vector allowed; + for (auto & path : targets) { + if (goal.isAllowed(path.path)) + allowed.emplace_back(path); + else + unknown.insert(path.path); + } + + next->queryMissing(allowed, willBuild, willSubstitute, + unknown, downloadSize, narSize); + } +}; + + +void DerivationGoal::startDaemon() +{ + settings.requireExperimentalFeature("recursive-nix"); + + Store::Params params; + params["path-info-cache-size"] = "0"; + params["store"] = worker.store.storeDir; + params["root"] = worker.store.rootDir; + params["state"] = "/no-such-path"; + params["log"] = "/no-such-path"; + auto store = make_ref(params, + ref(std::dynamic_pointer_cast(worker.store.shared_from_this())), + *this); + + addedPaths.clear(); + + auto socketName = ".nix-socket"; + Path socketPath = tmpDir + "/" + socketName; + env["NIX_REMOTE"] = "unix://" + tmpDirInSandbox + "/" + socketName; + + daemonSocket = createUnixDomainSocket(socketPath, 0600); + + chownToBuilder(socketPath); + + daemonThread = std::thread([this, store]() { + + while (true) { + + /* Accept a connection. */ + struct sockaddr_un remoteAddr; + socklen_t remoteAddrLen = sizeof(remoteAddr); + + AutoCloseFD remote = accept(daemonSocket.get(), + (struct sockaddr *) &remoteAddr, &remoteAddrLen); + if (!remote) { + if (errno == EINTR) continue; + if (errno == EINVAL) break; + throw SysError("accepting connection"); + } + + closeOnExec(remote.get()); + + debug("received daemon connection"); + + auto workerThread = std::thread([store, remote{std::move(remote)}]() { + FdSource from(remote.get()); + FdSink to(remote.get()); + try { + daemon::processConnection(store, from, to, + daemon::NotTrusted, daemon::Recursive, + [&](Store & store) { store.createUser("nobody", 65535); }); + debug("terminated daemon connection"); + } catch (SysError &) { + ignoreException(); + } + }); + + daemonWorkerThreads.push_back(std::move(workerThread)); + } + + debug("daemon shutting down"); + }); +} + + +void DerivationGoal::stopDaemon() +{ + if (daemonSocket && shutdown(daemonSocket.get(), SHUT_RDWR) == -1) + throw SysError("shutting down daemon socket"); + + if (daemonThread.joinable()) + daemonThread.join(); + + // FIXME: should prune worker threads more quickly. + // FIXME: shutdown the client socket to speed up worker termination. + for (auto & thread : daemonWorkerThreads) + thread.join(); + daemonWorkerThreads.clear(); + + daemonSocket = -1; +} + + +void DerivationGoal::addDependency(const StorePath & path) +{ + if (isAllowed(path)) return; + + addedPaths.insert(path); + + /* If we're doing a sandbox build, then we have to make the path + appear in the sandbox. */ + if (useChroot) { + + debug("materialising '%s' in the sandbox", worker.store.printStorePath(path)); + + #if __linux__ + + Path source = worker.store.Store::toRealPath(path); + Path target = chrootRootDir + worker.store.printStorePath(path); + debug("bind-mounting %s -> %s", target, source); + + if (pathExists(target)) + throw Error("store path '%s' already exists in the sandbox", worker.store.printStorePath(path)); + + auto st = lstat(source); + + if (S_ISDIR(st.st_mode)) { + + /* Bind-mount the path into the sandbox. This requires + entering its mount namespace, which is not possible + in multithreaded programs. So we do this in a + child process.*/ + Pid child(startProcess([&]() { + + if (setns(sandboxMountNamespace.get(), 0) == -1) + throw SysError("entering sandbox mount namespace"); + + createDirs(target); + + if (mount(source.c_str(), target.c_str(), "", MS_BIND, 0) == -1) + throw SysError("bind mount from '%s' to '%s' failed", source, target); + + _exit(0); + })); + + int status = child.wait(); + if (status != 0) + throw Error("could not add path '%s' to sandbox", worker.store.printStorePath(path)); + + } else + linkOrCopy(source, target); + + #else + throw Error("don't know how to make path '%s' (produced by a recursive Nix call) appear in the sandbox", + worker.store.printStorePath(path)); + #endif + + } +} + + +void DerivationGoal::chownToBuilder(const Path & path) +{ + if (!buildUser) return; + if (chown(path.c_str(), buildUser->getUID(), buildUser->getGID()) == -1) + throw SysError("cannot change ownership of '%1%'", path); +} + + +void setupSeccomp() +{ +#if __linux__ + if (!settings.filterSyscalls) return; +#if HAVE_SECCOMP + scmp_filter_ctx ctx; + + if (!(ctx = seccomp_init(SCMP_ACT_ALLOW))) + throw SysError("unable to initialize seccomp mode 2"); + + Finally cleanup([&]() { + seccomp_release(ctx); + }); + + if (nativeSystem == "x86_64-linux" && + seccomp_arch_add(ctx, SCMP_ARCH_X86) != 0) + throw SysError("unable to add 32-bit seccomp architecture"); + + if (nativeSystem == "x86_64-linux" && + seccomp_arch_add(ctx, SCMP_ARCH_X32) != 0) + throw SysError("unable to add X32 seccomp architecture"); + + if (nativeSystem == "aarch64-linux" && + seccomp_arch_add(ctx, SCMP_ARCH_ARM) != 0) + printError("unable to add ARM seccomp architecture; this may result in spurious build failures if running 32-bit ARM processes"); + + /* Prevent builders from creating setuid/setgid binaries. */ + for (int perm : { S_ISUID, S_ISGID }) { + if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(chmod), 1, + SCMP_A1(SCMP_CMP_MASKED_EQ, (scmp_datum_t) perm, (scmp_datum_t) perm)) != 0) + throw SysError("unable to add seccomp rule"); + + if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(fchmod), 1, + SCMP_A1(SCMP_CMP_MASKED_EQ, (scmp_datum_t) perm, (scmp_datum_t) perm)) != 0) + throw SysError("unable to add seccomp rule"); + + if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(fchmodat), 1, + SCMP_A2(SCMP_CMP_MASKED_EQ, (scmp_datum_t) perm, (scmp_datum_t) perm)) != 0) + throw SysError("unable to add seccomp rule"); + } + + /* Prevent builders from creating EAs or ACLs. Not all filesystems + support these, and they're not allowed in the Nix store because + they're not representable in the NAR serialisation. */ + if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(setxattr), 0) != 0 || + seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(lsetxattr), 0) != 0 || + seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(fsetxattr), 0) != 0) + throw SysError("unable to add seccomp rule"); + + if (seccomp_attr_set(ctx, SCMP_FLTATR_CTL_NNP, settings.allowNewPrivileges ? 0 : 1) != 0) + throw SysError("unable to set 'no new privileges' seccomp attribute"); + + if (seccomp_load(ctx) != 0) + throw SysError("unable to load seccomp BPF program"); +#else + throw Error( + "seccomp is not supported on this platform; " + "you can bypass this error by setting the option 'filter-syscalls' to false, but note that untrusted builds can then create setuid binaries!"); +#endif +#endif +} + + +void DerivationGoal::runChild() +{ + /* Warning: in the child we should absolutely not make any SQLite + calls! */ + + try { /* child */ + + commonChildInit(builderOut); + + try { + setupSeccomp(); + } catch (...) { + if (buildUser) throw; + } + + bool setUser = true; + + /* Make the contents of netrc available to builtin:fetchurl + (which may run under a different uid and/or in a sandbox). */ + std::string netrcData; + try { + if (drv->isBuiltin() && drv->builder == "builtin:fetchurl") + netrcData = readFile(settings.netrcFile); + } catch (SysError &) { } + +#if __linux__ + if (useChroot) { + + userNamespaceSync.writeSide = -1; + + if (drainFD(userNamespaceSync.readSide.get()) != "1") + throw Error("user namespace initialisation failed"); + + userNamespaceSync.readSide = -1; + + if (privateNetwork) { + + /* Initialise the loopback interface. */ + AutoCloseFD fd(socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)); + if (!fd) throw SysError("cannot open IP socket"); + + struct ifreq ifr; + strcpy(ifr.ifr_name, "lo"); + ifr.ifr_flags = IFF_UP | IFF_LOOPBACK | IFF_RUNNING; + if (ioctl(fd.get(), SIOCSIFFLAGS, &ifr) == -1) + throw SysError("cannot set loopback interface flags"); + } + + /* Set the hostname etc. to fixed values. */ + char hostname[] = "localhost"; + if (sethostname(hostname, sizeof(hostname)) == -1) + throw SysError("cannot set host name"); + char domainname[] = "(none)"; // kernel default + if (setdomainname(domainname, sizeof(domainname)) == -1) + throw SysError("cannot set domain name"); + + /* Make all filesystems private. This is necessary + because subtrees may have been mounted as "shared" + (MS_SHARED). (Systemd does this, for instance.) Even + though we have a private mount namespace, mounting + filesystems on top of a shared subtree still propagates + outside of the namespace. Making a subtree private is + local to the namespace, though, so setting MS_PRIVATE + does not affect the outside world. */ + if (mount(0, "/", 0, MS_PRIVATE | MS_REC, 0) == -1) + throw SysError("unable to make '/' private"); + + /* Bind-mount chroot directory to itself, to treat it as a + different filesystem from /, as needed for pivot_root. */ + if (mount(chrootRootDir.c_str(), chrootRootDir.c_str(), 0, MS_BIND, 0) == -1) + throw SysError("unable to bind mount '%1%'", chrootRootDir); + + /* Bind-mount the sandbox's Nix store onto itself so that + we can mark it as a "shared" subtree, allowing bind + mounts made in *this* mount namespace to be propagated + into the child namespace created by the + unshare(CLONE_NEWNS) call below. + + Marking chrootRootDir as MS_SHARED causes pivot_root() + to fail with EINVAL. Don't know why. */ + Path chrootStoreDir = chrootRootDir + worker.store.storeDir; + + if (mount(chrootStoreDir.c_str(), chrootStoreDir.c_str(), 0, MS_BIND, 0) == -1) + throw SysError("unable to bind mount the Nix store", chrootStoreDir); + + if (mount(0, chrootStoreDir.c_str(), 0, MS_SHARED, 0) == -1) + throw SysError("unable to make '%s' shared", chrootStoreDir); + + /* Set up a nearly empty /dev, unless the user asked to + bind-mount the host /dev. */ + Strings ss; + if (dirsInChroot.find("/dev") == dirsInChroot.end()) { + createDirs(chrootRootDir + "/dev/shm"); + createDirs(chrootRootDir + "/dev/pts"); + ss.push_back("/dev/full"); + if (worker.store.systemFeatures.get().count("kvm") && pathExists("/dev/kvm")) + ss.push_back("/dev/kvm"); + ss.push_back("/dev/null"); + ss.push_back("/dev/random"); + ss.push_back("/dev/tty"); + ss.push_back("/dev/urandom"); + ss.push_back("/dev/zero"); + createSymlink("/proc/self/fd", chrootRootDir + "/dev/fd"); + createSymlink("/proc/self/fd/0", chrootRootDir + "/dev/stdin"); + createSymlink("/proc/self/fd/1", chrootRootDir + "/dev/stdout"); + createSymlink("/proc/self/fd/2", chrootRootDir + "/dev/stderr"); + } + + /* Fixed-output derivations typically need to access the + network, so give them access to /etc/resolv.conf and so + on. */ + if (derivationIsImpure(derivationType)) { + ss.push_back("/etc/resolv.conf"); + + // Only use nss functions to resolve hosts and + // services. Don’t use it for anything else that may + // be configured for this system. This limits the + // potential impurities introduced in fixed-outputs. + writeFile(chrootRootDir + "/etc/nsswitch.conf", "hosts: files dns\nservices: files\n"); + + ss.push_back("/etc/services"); + ss.push_back("/etc/hosts"); + if (pathExists("/var/run/nscd/socket")) + ss.push_back("/var/run/nscd/socket"); + } + + for (auto & i : ss) dirsInChroot.emplace(i, i); + + /* Bind-mount all the directories from the "host" + filesystem that we want in the chroot + environment. */ + auto doBind = [&](const Path & source, const Path & target, bool optional = false) { + debug("bind mounting '%1%' to '%2%'", source, target); + struct stat st; + if (stat(source.c_str(), &st) == -1) { + if (optional && errno == ENOENT) + return; + else + throw SysError("getting attributes of path '%1%'", source); + } + if (S_ISDIR(st.st_mode)) + createDirs(target); + else { + createDirs(dirOf(target)); + writeFile(target, ""); + } + if (mount(source.c_str(), target.c_str(), "", MS_BIND | MS_REC, 0) == -1) + throw SysError("bind mount from '%1%' to '%2%' failed", source, target); + }; + + for (auto & i : dirsInChroot) { + if (i.second.source == "/proc") continue; // backwards compatibility + doBind(i.second.source, chrootRootDir + i.first, i.second.optional); + } + + /* Bind a new instance of procfs on /proc. */ + createDirs(chrootRootDir + "/proc"); + if (mount("none", (chrootRootDir + "/proc").c_str(), "proc", 0, 0) == -1) + throw SysError("mounting /proc"); + + /* Mount a new tmpfs on /dev/shm to ensure that whatever + the builder puts in /dev/shm is cleaned up automatically. */ + if (pathExists("/dev/shm") && mount("none", (chrootRootDir + "/dev/shm").c_str(), "tmpfs", 0, + fmt("size=%s", settings.sandboxShmSize).c_str()) == -1) + throw SysError("mounting /dev/shm"); + + /* Mount a new devpts on /dev/pts. Note that this + requires the kernel to be compiled with + CONFIG_DEVPTS_MULTIPLE_INSTANCES=y (which is the case + if /dev/ptx/ptmx exists). */ + if (pathExists("/dev/pts/ptmx") && + !pathExists(chrootRootDir + "/dev/ptmx") + && !dirsInChroot.count("/dev/pts")) + { + if (mount("none", (chrootRootDir + "/dev/pts").c_str(), "devpts", 0, "newinstance,mode=0620") == 0) + { + createSymlink("/dev/pts/ptmx", chrootRootDir + "/dev/ptmx"); + + /* Make sure /dev/pts/ptmx is world-writable. With some + Linux versions, it is created with permissions 0. */ + chmod_(chrootRootDir + "/dev/pts/ptmx", 0666); + } else { + if (errno != EINVAL) + throw SysError("mounting /dev/pts"); + doBind("/dev/pts", chrootRootDir + "/dev/pts"); + doBind("/dev/ptmx", chrootRootDir + "/dev/ptmx"); + } + } + + /* Unshare this mount namespace. This is necessary because + pivot_root() below changes the root of the mount + namespace. This means that the call to setns() in + addDependency() would hide the host's filesystem, + making it impossible to bind-mount paths from the host + Nix store into the sandbox. Therefore, we save the + pre-pivot_root namespace in + sandboxMountNamespace. Since we made /nix/store a + shared subtree above, this allows addDependency() to + make paths appear in the sandbox. */ + if (unshare(CLONE_NEWNS) == -1) + throw SysError("unsharing mount namespace"); + + /* Do the chroot(). */ + if (chdir(chrootRootDir.c_str()) == -1) + throw SysError("cannot change directory to '%1%'", chrootRootDir); + + if (mkdir("real-root", 0) == -1) + throw SysError("cannot create real-root directory"); + + if (pivot_root(".", "real-root") == -1) + throw SysError("cannot pivot old root directory onto '%1%'", (chrootRootDir + "/real-root")); + + if (chroot(".") == -1) + throw SysError("cannot change root directory to '%1%'", chrootRootDir); + + if (umount2("real-root", MNT_DETACH) == -1) + throw SysError("cannot unmount real root filesystem"); + + if (rmdir("real-root") == -1) + throw SysError("cannot remove real-root directory"); + + /* Switch to the sandbox uid/gid in the user namespace, + which corresponds to the build user or calling user in + the parent namespace. */ + if (setgid(sandboxGid()) == -1) + throw SysError("setgid failed"); + if (setuid(sandboxUid()) == -1) + throw SysError("setuid failed"); + + setUser = false; + } +#endif + + if (chdir(tmpDirInSandbox.c_str()) == -1) + throw SysError("changing into '%1%'", tmpDir); + + /* Close all other file descriptors. */ + closeMostFDs({STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO}); + +#if __linux__ + /* Change the personality to 32-bit if we're doing an + i686-linux build on an x86_64-linux machine. */ + struct utsname utsbuf; + uname(&utsbuf); + if (drv->platform == "i686-linux" && + (settings.thisSystem == "x86_64-linux" || + (!strcmp(utsbuf.sysname, "Linux") && !strcmp(utsbuf.machine, "x86_64")))) { + if (personality(PER_LINUX32) == -1) + throw SysError("cannot set i686-linux personality"); + } + + /* Impersonate a Linux 2.6 machine to get some determinism in + builds that depend on the kernel version. */ + if ((drv->platform == "i686-linux" || drv->platform == "x86_64-linux") && settings.impersonateLinux26) { + int cur = personality(0xffffffff); + if (cur != -1) personality(cur | 0x0020000 /* == UNAME26 */); + } + + /* Disable address space randomization for improved + determinism. */ + int cur = personality(0xffffffff); + if (cur != -1) personality(cur | ADDR_NO_RANDOMIZE); +#endif + + /* Disable core dumps by default. */ + struct rlimit limit = { 0, RLIM_INFINITY }; + setrlimit(RLIMIT_CORE, &limit); + + // FIXME: set other limits to deterministic values? + + /* Fill in the environment. */ + Strings envStrs; + for (auto & i : env) + envStrs.push_back(rewriteStrings(i.first + "=" + i.second, inputRewrites)); + + /* If we are running in `build-users' mode, then switch to the + user we allocated above. Make sure that we drop all root + privileges. Note that above we have closed all file + descriptors except std*, so that's safe. Also note that + setuid() when run as root sets the real, effective and + saved UIDs. */ + if (setUser && buildUser) { + /* Preserve supplementary groups of the build user, to allow + admins to specify groups such as "kvm". */ + if (!buildUser->getSupplementaryGIDs().empty() && + setgroups(buildUser->getSupplementaryGIDs().size(), + buildUser->getSupplementaryGIDs().data()) == -1) + throw SysError("cannot set supplementary groups of build user"); + + if (setgid(buildUser->getGID()) == -1 || + getgid() != buildUser->getGID() || + getegid() != buildUser->getGID()) + throw SysError("setgid failed"); + + if (setuid(buildUser->getUID()) == -1 || + getuid() != buildUser->getUID() || + geteuid() != buildUser->getUID()) + throw SysError("setuid failed"); + } + + /* Fill in the arguments. */ + Strings args; + + const char *builder = "invalid"; + + if (drv->isBuiltin()) { + ; + } +#if __APPLE__ + else { + /* This has to appear before import statements. */ + std::string sandboxProfile = "(version 1)\n"; + + if (useChroot) { + + /* Lots and lots and lots of file functions freak out if they can't stat their full ancestry */ + PathSet ancestry; + + /* We build the ancestry before adding all inputPaths to the store because we know they'll + all have the same parents (the store), and there might be lots of inputs. This isn't + particularly efficient... I doubt it'll be a bottleneck in practice */ + for (auto & i : dirsInChroot) { + Path cur = i.first; + while (cur.compare("/") != 0) { + cur = dirOf(cur); + ancestry.insert(cur); + } + } + + /* And we want the store in there regardless of how empty dirsInChroot. We include the innermost + path component this time, since it's typically /nix/store and we care about that. */ + Path cur = worker.store.storeDir; + while (cur.compare("/") != 0) { + ancestry.insert(cur); + cur = dirOf(cur); + } + + /* Add all our input paths to the chroot */ + for (auto & i : inputPaths) { + auto p = worker.store.printStorePath(i); + dirsInChroot[p] = p; + } + + /* Violations will go to the syslog if you set this. Unfortunately the destination does not appear to be configurable */ + if (settings.darwinLogSandboxViolations) { + sandboxProfile += "(deny default)\n"; + } else { + sandboxProfile += "(deny default (with no-log))\n"; + } + + sandboxProfile += "(import \"sandbox-defaults.sb\")\n"; + + if (derivationIsImpure(derivationType)) + sandboxProfile += "(import \"sandbox-network.sb\")\n"; + + /* Add the output paths we'll use at build-time to the chroot */ + sandboxProfile += "(allow file-read* file-write* process-exec\n"; + for (auto & [_, path] : scratchOutputs) + sandboxProfile += fmt("\t(subpath \"%s\")\n", worker.store.printStorePath(path)); + + sandboxProfile += ")\n"; + + /* Our inputs (transitive dependencies and any impurities computed above) + + without file-write* allowed, access() incorrectly returns EPERM + */ + sandboxProfile += "(allow file-read* file-write* process-exec\n"; + for (auto & i : dirsInChroot) { + if (i.first != i.second.source) + throw Error( + "can't map '%1%' to '%2%': mismatched impure paths not supported on Darwin", + i.first, i.second.source); + + string path = i.first; + struct stat st; + if (lstat(path.c_str(), &st)) { + if (i.second.optional && errno == ENOENT) + continue; + throw SysError("getting attributes of path '%s", path); + } + if (S_ISDIR(st.st_mode)) + sandboxProfile += fmt("\t(subpath \"%s\")\n", path); + else + sandboxProfile += fmt("\t(literal \"%s\")\n", path); + } + sandboxProfile += ")\n"; + + /* Allow file-read* on full directory hierarchy to self. Allows realpath() */ + sandboxProfile += "(allow file-read*\n"; + for (auto & i : ancestry) { + sandboxProfile += fmt("\t(literal \"%s\")\n", i); + } + sandboxProfile += ")\n"; + + sandboxProfile += additionalSandboxProfile; + } else + sandboxProfile += "(import \"sandbox-minimal.sb\")\n"; + + debug("Generated sandbox profile:"); + debug(sandboxProfile); + + Path sandboxFile = tmpDir + "/.sandbox.sb"; + + writeFile(sandboxFile, sandboxProfile); + + bool allowLocalNetworking = parsedDrv->getBoolAttr("__darwinAllowLocalNetworking"); + + /* The tmpDir in scope points at the temporary build directory for our derivation. Some packages try different mechanisms + to find temporary directories, so we want to open up a broader place for them to dump their files, if needed. */ + Path globalTmpDir = canonPath(getEnv("TMPDIR").value_or("/tmp"), true); + + /* They don't like trailing slashes on subpath directives */ + if (globalTmpDir.back() == '/') globalTmpDir.pop_back(); + + if (getEnv("_NIX_TEST_NO_SANDBOX") != "1") { + builder = "/usr/bin/sandbox-exec"; + args.push_back("sandbox-exec"); + args.push_back("-f"); + args.push_back(sandboxFile); + args.push_back("-D"); + args.push_back("_GLOBAL_TMP_DIR=" + globalTmpDir); + args.push_back("-D"); + args.push_back("IMPORT_DIR=" + settings.nixDataDir + "/nix/sandbox/"); + if (allowLocalNetworking) { + args.push_back("-D"); + args.push_back(string("_ALLOW_LOCAL_NETWORKING=1")); + } + args.push_back(drv->builder); + } else { + builder = drv->builder.c_str(); + args.push_back(std::string(baseNameOf(drv->builder))); + } + } +#else + else { + builder = drv->builder.c_str(); + args.push_back(std::string(baseNameOf(drv->builder))); + } +#endif + + for (auto & i : drv->args) + args.push_back(rewriteStrings(i, inputRewrites)); + + /* Indicate that we managed to set up the build environment. */ + writeFull(STDERR_FILENO, string("\2\n")); + + /* Execute the program. This should not return. */ + if (drv->isBuiltin()) { + try { + logger = makeJSONLogger(*logger); + + BasicDerivation & drv2(*drv); + for (auto & e : drv2.env) + e.second = rewriteStrings(e.second, inputRewrites); + + if (drv->builder == "builtin:fetchurl") + builtinFetchurl(drv2, netrcData); + else if (drv->builder == "builtin:buildenv") + builtinBuildenv(drv2); + else if (drv->builder == "builtin:unpack-channel") + builtinUnpackChannel(drv2); + else + throw Error("unsupported builtin function '%1%'", string(drv->builder, 8)); + _exit(0); + } catch (std::exception & e) { + writeFull(STDERR_FILENO, e.what() + std::string("\n")); + _exit(1); + } + } + + execve(builder, stringsToCharPtrs(args).data(), stringsToCharPtrs(envStrs).data()); + + throw SysError("executing '%1%'", drv->builder); + + } catch (Error & e) { + writeFull(STDERR_FILENO, "\1\n"); + FdSink sink(STDERR_FILENO); + sink << e; + sink.flush(); + _exit(1); + } +} + + +void DerivationGoal::registerOutputs() +{ + /* When using a build hook, the build hook can register the output + as valid (by doing `nix-store --import'). If so we don't have + to do anything here. + + We can only early return when the outputs are known a priori. For + floating content-addressed derivations this isn't the case. + */ + if (hook) { + bool allValid = true; + for (auto & i : drv->outputsAndOptPaths(worker.store)) { + if (!i.second.second || !worker.store.isValidPath(*i.second.second)) + allValid = false; + } + if (allValid) return; + } + + std::map infos; + + /* Set of inodes seen during calls to canonicalisePathMetaData() + for this build's outputs. This needs to be shared between + outputs to allow hard links between outputs. */ + InodesSeen inodesSeen; + + Path checkSuffix = ".check"; + bool keepPreviousRound = settings.keepFailed || settings.runDiffHook; + + std::exception_ptr delayedException; + + /* The paths that can be referenced are the input closures, the + output paths, and any paths that have been built via recursive + Nix calls. */ + StorePathSet referenceablePaths; + for (auto & p : inputPaths) referenceablePaths.insert(p); + for (auto & i : scratchOutputs) referenceablePaths.insert(i.second); + for (auto & p : addedPaths) referenceablePaths.insert(p); + + /* FIXME `needsHashRewrite` should probably be removed and we get to the + real reason why we aren't using the chroot dir */ + auto toRealPathChroot = [&](const Path & p) -> Path { + return useChroot && !needsHashRewrite() + ? chrootRootDir + p + : worker.store.toRealPath(p); + }; + + /* Check whether the output paths were created, and make all + output paths read-only. Then get the references of each output (that we + might need to register), so we can topologically sort them. For the ones + that are most definitely already installed, we just store their final + name so we can also use it in rewrites. */ + StringSet outputsToSort; + struct AlreadyRegistered { StorePath path; }; + struct PerhapsNeedToRegister { StorePathSet refs; }; + std::map> outputReferencesIfUnregistered; + std::map outputStats; + for (auto & [outputName, _] : drv->outputs) { + auto actualPath = toRealPathChroot(worker.store.printStorePath(scratchOutputs.at(outputName))); + + outputsToSort.insert(outputName); + + /* Updated wanted info to remove the outputs we definitely don't need to register */ + auto & initialInfo = initialOutputs.at(outputName); + + /* Don't register if already valid, and not checking */ + initialInfo.wanted = buildMode == bmCheck + || !(initialInfo.known && initialInfo.known->isValid()); + if (!initialInfo.wanted) { + outputReferencesIfUnregistered.insert_or_assign( + outputName, + AlreadyRegistered { .path = initialInfo.known->path }); + continue; + } + + struct stat st; + if (lstat(actualPath.c_str(), &st) == -1) { + if (errno == ENOENT) + throw BuildError( + "builder for '%s' failed to produce output path for output '%s' at '%s'", + worker.store.printStorePath(drvPath), outputName, actualPath); + throw SysError("getting attributes of path '%s'", actualPath); + } + +#ifndef __CYGWIN__ + /* Check that the output is not group or world writable, as + that means that someone else can have interfered with the + build. Also, the output should be owned by the build + user. */ + if ((!S_ISLNK(st.st_mode) && (st.st_mode & (S_IWGRP | S_IWOTH))) || + (buildUser && st.st_uid != buildUser->getUID())) + throw BuildError( + "suspicious ownership or permission on '%s' for output '%s'; rejecting this build output", + actualPath, outputName); +#endif + + /* Canonicalise first. This ensures that the path we're + rewriting doesn't contain a hard link to /etc/shadow or + something like that. */ + canonicalisePathMetaData(actualPath, buildUser ? buildUser->getUID() : -1, inodesSeen); + + debug("scanning for references for output '%s' in temp location '%s'", outputName, actualPath); + + /* Pass blank Sink as we are not ready to hash data at this stage. */ + NullSink blank; + auto references = worker.store.parseStorePathSet( + scanForReferences(blank, actualPath, worker.store.printStorePathSet(referenceablePaths))); + + outputReferencesIfUnregistered.insert_or_assign( + outputName, + PerhapsNeedToRegister { .refs = references }); + outputStats.insert_or_assign(outputName, std::move(st)); + } + + auto sortedOutputNames = topoSort(outputsToSort, + {[&](const std::string & name) { + return std::visit(overloaded { + /* Since we'll use the already installed versions of these, we + can treat them as leaves and ignore any references they + have. */ + [&](AlreadyRegistered _) { return StringSet {}; }, + [&](PerhapsNeedToRegister refs) { + StringSet referencedOutputs; + /* FIXME build inverted map up front so no quadratic waste here */ + for (auto & r : refs.refs) + for (auto & [o, p] : scratchOutputs) + if (r == p) + referencedOutputs.insert(o); + return referencedOutputs; + }, + }, outputReferencesIfUnregistered.at(name)); + }}, + {[&](const std::string & path, const std::string & parent) { + // TODO with more -vvvv also show the temporary paths for manual inspection. + return BuildError( + "cycle detected in build of '%s' in the references of output '%s' from output '%s'", + worker.store.printStorePath(drvPath), path, parent); + }}); + + std::reverse(sortedOutputNames.begin(), sortedOutputNames.end()); + + for (auto & outputName : sortedOutputNames) { + auto output = drv->outputs.at(outputName); + auto & scratchPath = scratchOutputs.at(outputName); + auto actualPath = toRealPathChroot(worker.store.printStorePath(scratchPath)); + + auto finish = [&](StorePath finalStorePath) { + /* Store the final path */ + finalOutputs.insert_or_assign(outputName, finalStorePath); + /* The rewrite rule will be used in downstream outputs that refer to + use. This is why the topological sort is essential to do first + before this for loop. */ + if (scratchPath != finalStorePath) + outputRewrites[std::string { scratchPath.hashPart() }] = std::string { finalStorePath.hashPart() }; + }; + + std::optional referencesOpt = std::visit(overloaded { + [&](AlreadyRegistered skippedFinalPath) -> std::optional { + finish(skippedFinalPath.path); + return std::nullopt; + }, + [&](PerhapsNeedToRegister r) -> std::optional { + return r.refs; + }, + }, outputReferencesIfUnregistered.at(outputName)); + + if (!referencesOpt) + continue; + auto references = *referencesOpt; + + auto rewriteOutput = [&]() { + /* Apply hash rewriting if necessary. */ + if (!outputRewrites.empty()) { + logWarning({ + .name = "Rewriting hashes", + .hint = hintfmt("rewriting hashes in '%1%'; cross fingers", actualPath), + }); + + /* FIXME: this is in-memory. */ + StringSink sink; + dumpPath(actualPath, sink); + deletePath(actualPath); + sink.s = make_ref(rewriteStrings(*sink.s, outputRewrites)); + StringSource source(*sink.s); + restorePath(actualPath, source); + + /* FIXME: set proper permissions in restorePath() so + we don't have to do another traversal. */ + canonicalisePathMetaData(actualPath, -1, inodesSeen); + } + }; + + auto rewriteRefs = [&]() -> std::pair { + /* In the CA case, we need the rewritten refs to calculate the + final path, therefore we look for a *non-rewritten + self-reference, and use a bool rather try to solve the + computationally intractable fixed point. */ + std::pair res { + false, + {}, + }; + for (auto & r : references) { + auto name = r.name(); + auto origHash = std::string { r.hashPart() }; + if (r == scratchPath) + res.first = true; + else if (outputRewrites.count(origHash) == 0) + res.second.insert(r); + else { + std::string newRef = outputRewrites.at(origHash); + newRef += '-'; + newRef += name; + res.second.insert(StorePath { newRef }); + } + } + return res; + }; + + auto newInfoFromCA = [&](const DerivationOutputCAFloating outputHash) -> ValidPathInfo { + auto & st = outputStats.at(outputName); + if (outputHash.method == FileIngestionMethod::Flat) { + /* The output path should be a regular file without execute permission. */ + if (!S_ISREG(st.st_mode) || (st.st_mode & S_IXUSR) != 0) + throw BuildError( + "output path '%1%' should be a non-executable regular file " + "since recursive hashing is not enabled (outputHashMode=flat)", + actualPath); + } + rewriteOutput(); + /* FIXME optimize and deduplicate with addToStore */ + std::string oldHashPart { scratchPath.hashPart() }; + HashModuloSink caSink { outputHash.hashType, oldHashPart }; + switch (outputHash.method) { + case FileIngestionMethod::Recursive: + dumpPath(actualPath, caSink); + break; + case FileIngestionMethod::Flat: + readFile(actualPath, caSink); + break; + } + auto got = caSink.finish().first; + auto refs = rewriteRefs(); + HashModuloSink narSink { htSHA256, oldHashPart }; + dumpPath(actualPath, narSink); + auto narHashAndSize = narSink.finish(); + ValidPathInfo newInfo0 { + worker.store.makeFixedOutputPath( + outputHash.method, + got, + outputPathName(drv->name, outputName), + refs.second, + refs.first), + narHashAndSize.first, + }; + newInfo0.narSize = narHashAndSize.second; + newInfo0.ca = FixedOutputHash { + .method = outputHash.method, + .hash = got, + }; + newInfo0.references = refs.second; + if (refs.first) + newInfo0.references.insert(newInfo0.path); + + assert(newInfo0.ca); + return newInfo0; + }; + + ValidPathInfo newInfo = std::visit(overloaded { + [&](DerivationOutputInputAddressed output) { + /* input-addressed case */ + auto requiredFinalPath = output.path; + /* Preemptively add rewrite rule for final hash, as that is + what the NAR hash will use rather than normalized-self references */ + if (scratchPath != requiredFinalPath) + outputRewrites.insert_or_assign( + std::string { scratchPath.hashPart() }, + std::string { requiredFinalPath.hashPart() }); + rewriteOutput(); + auto narHashAndSize = hashPath(htSHA256, actualPath); + ValidPathInfo newInfo0 { requiredFinalPath, narHashAndSize.first }; + newInfo0.narSize = narHashAndSize.second; + auto refs = rewriteRefs(); + newInfo0.references = refs.second; + if (refs.first) + newInfo0.references.insert(newInfo0.path); + return newInfo0; + }, + [&](DerivationOutputCAFixed dof) { + auto newInfo0 = newInfoFromCA(DerivationOutputCAFloating { + .method = dof.hash.method, + .hashType = dof.hash.hash.type, + }); + + /* Check wanted hash */ + Hash & wanted = dof.hash.hash; + assert(newInfo0.ca); + auto got = getContentAddressHash(*newInfo0.ca); + if (wanted != got) { + /* Throw an error after registering the path as + valid. */ + worker.hashMismatch = true; + delayedException = std::make_exception_ptr( + BuildError("hash mismatch in fixed-output derivation '%s':\n wanted: %s\n got: %s", + worker.store.printStorePath(drvPath), + wanted.to_string(SRI, true), + got.to_string(SRI, true))); + } + return newInfo0; + }, + [&](DerivationOutputCAFloating dof) { + return newInfoFromCA(dof); + }, + }, output.output); + + /* Calculate where we'll move the output files. In the checking case we + will leave leave them where they are, for now, rather than move to + their usual "final destination" */ + auto finalDestPath = worker.store.printStorePath(newInfo.path); + + /* Lock final output path, if not already locked. This happens with + floating CA derivations and hash-mismatching fixed-output + derivations. */ + PathLocks dynamicOutputLock; + auto optFixedPath = output.path(worker.store, drv->name, outputName); + if (!optFixedPath || + worker.store.printStorePath(*optFixedPath) != finalDestPath) + { + assert(newInfo.ca); + dynamicOutputLock.lockPaths({worker.store.toRealPath(finalDestPath)}); + } + + /* Move files, if needed */ + if (worker.store.toRealPath(finalDestPath) != actualPath) { + if (buildMode == bmRepair) { + /* Path already exists, need to replace it */ + replaceValidPath(worker.store.toRealPath(finalDestPath), actualPath); + actualPath = worker.store.toRealPath(finalDestPath); + } else if (buildMode == bmCheck) { + /* Path already exists, and we want to compare, so we leave out + new path in place. */ + } else if (worker.store.isValidPath(newInfo.path)) { + /* Path already exists because CA path produced by something + else. No moving needed. */ + assert(newInfo.ca); + } else { + auto destPath = worker.store.toRealPath(finalDestPath); + movePath(actualPath, destPath); + actualPath = destPath; + } + } + + if (buildMode == bmCheck) { + if (!worker.store.isValidPath(newInfo.path)) continue; + ValidPathInfo oldInfo(*worker.store.queryPathInfo(newInfo.path)); + if (newInfo.narHash != oldInfo.narHash) { + worker.checkMismatch = true; + if (settings.runDiffHook || settings.keepFailed) { + auto dst = worker.store.toRealPath(finalDestPath + checkSuffix); + deletePath(dst); + movePath(actualPath, dst); + + handleDiffHook( + buildUser ? buildUser->getUID() : getuid(), + buildUser ? buildUser->getGID() : getgid(), + finalDestPath, dst, worker.store.printStorePath(drvPath), tmpDir); + + throw NotDeterministic("derivation '%s' may not be deterministic: output '%s' differs from '%s'", + worker.store.printStorePath(drvPath), worker.store.toRealPath(finalDestPath), dst); + } else + throw NotDeterministic("derivation '%s' may not be deterministic: output '%s' differs", + worker.store.printStorePath(drvPath), worker.store.toRealPath(finalDestPath)); + } + + /* Since we verified the build, it's now ultimately trusted. */ + if (!oldInfo.ultimate) { + oldInfo.ultimate = true; + worker.store.signPathInfo(oldInfo); + worker.store.registerValidPaths({ std::move(oldInfo) }); + } + + continue; + } + + /* For debugging, print out the referenced and unreferenced paths. */ + for (auto & i : inputPaths) { + auto j = references.find(i); + if (j == references.end()) + debug("unreferenced input: '%1%'", worker.store.printStorePath(i)); + else + debug("referenced input: '%1%'", worker.store.printStorePath(i)); + } + + if (curRound == nrRounds) { + worker.store.optimisePath(actualPath); // FIXME: combine with scanForReferences() + worker.markContentsGood(newInfo.path); + } + + newInfo.deriver = drvPath; + newInfo.ultimate = true; + worker.store.signPathInfo(newInfo); + + finish(newInfo.path); + + /* If it's a CA path, register it right away. This is necessary if it + isn't statically known so that we can safely unlock the path before + the next iteration */ + if (newInfo.ca) + worker.store.registerValidPaths({newInfo}); + + infos.emplace(outputName, std::move(newInfo)); + } + + if (buildMode == bmCheck) return; + + /* Apply output checks. */ + checkOutputs(infos); + + /* Compare the result with the previous round, and report which + path is different, if any.*/ + if (curRound > 1 && prevInfos != infos) { + assert(prevInfos.size() == infos.size()); + for (auto i = prevInfos.begin(), j = infos.begin(); i != prevInfos.end(); ++i, ++j) + if (!(*i == *j)) { + result.isNonDeterministic = true; + Path prev = worker.store.printStorePath(i->second.path) + checkSuffix; + bool prevExists = keepPreviousRound && pathExists(prev); + hintformat hint = prevExists + ? hintfmt("output '%s' of '%s' differs from '%s' from previous round", + worker.store.printStorePath(i->second.path), worker.store.printStorePath(drvPath), prev) + : hintfmt("output '%s' of '%s' differs from previous round", + worker.store.printStorePath(i->second.path), worker.store.printStorePath(drvPath)); + + handleDiffHook( + buildUser ? buildUser->getUID() : getuid(), + buildUser ? buildUser->getGID() : getgid(), + prev, worker.store.printStorePath(i->second.path), + worker.store.printStorePath(drvPath), tmpDir); + + if (settings.enforceDeterminism) + throw NotDeterministic(hint); + + logError({ + .name = "Output determinism error", + .hint = hint + }); + + curRound = nrRounds; // we know enough, bail out early + } + } + + /* If this is the first round of several, then move the output out of the way. */ + if (nrRounds > 1 && curRound == 1 && curRound < nrRounds && keepPreviousRound) { + for (auto & [_, outputStorePath] : finalOutputs) { + auto path = worker.store.printStorePath(outputStorePath); + Path prev = path + checkSuffix; + deletePath(prev); + Path dst = path + checkSuffix; + if (rename(path.c_str(), dst.c_str())) + throw SysError("renaming '%s' to '%s'", path, dst); + } + } + + if (curRound < nrRounds) { + prevInfos = std::move(infos); + return; + } + + /* Remove the .check directories if we're done. FIXME: keep them + if the result was not determistic? */ + if (curRound == nrRounds) { + for (auto & [_, outputStorePath] : finalOutputs) { + Path prev = worker.store.printStorePath(outputStorePath) + checkSuffix; + deletePath(prev); + } + } + + /* Register each output path as valid, and register the sets of + paths referenced by each of them. If there are cycles in the + outputs, this will fail. */ + { + ValidPathInfos infos2; + for (auto & [outputName, newInfo] : infos) { + infos2.push_back(newInfo); + } + worker.store.registerValidPaths(infos2); + } + + /* In case of a fixed-output derivation hash mismatch, throw an + exception now that we have registered the output as valid. */ + if (delayedException) + std::rethrow_exception(delayedException); + + /* If we made it this far, we are sure the output matches the derivation + (since the delayedException would be a fixed output CA mismatch). That + means it's safe to link the derivation to the output hash. We must do + that for floating CA derivations, which otherwise couldn't be cached, + but it's fine to do in all cases. */ + bool isCaFloating = drv->type() == DerivationType::CAFloating; + + auto drvPathResolved = drvPath; + if (!useDerivation && isCaFloating) { + /* Once a floating CA derivations reaches this point, it + must already be resolved, so we don't bother trying to + downcast drv to get would would just be an empty + inputDrvs field. */ + Derivation drv2 { *drv }; + drvPathResolved = writeDerivation(worker.store, drv2); + } + + if (useDerivation || isCaFloating) + for (auto & [outputName, newInfo] : infos) + worker.store.linkDeriverToPath(drvPathResolved, outputName, newInfo.path); +} + + +void DerivationGoal::checkOutputs(const std::map & outputs) +{ + std::map outputsByPath; + for (auto & output : outputs) + outputsByPath.emplace(worker.store.printStorePath(output.second.path), output.second); + + for (auto & output : outputs) { + auto & outputName = output.first; + auto & info = output.second; + + struct Checks + { + bool ignoreSelfRefs = false; + std::optional maxSize, maxClosureSize; + std::optional allowedReferences, allowedRequisites, disallowedReferences, disallowedRequisites; + }; + + /* Compute the closure and closure size of some output. This + is slightly tricky because some of its references (namely + other outputs) may not be valid yet. */ + auto getClosure = [&](const StorePath & path) + { + uint64_t closureSize = 0; + StorePathSet pathsDone; + std::queue pathsLeft; + pathsLeft.push(path); + + while (!pathsLeft.empty()) { + auto path = pathsLeft.front(); + pathsLeft.pop(); + if (!pathsDone.insert(path).second) continue; + + auto i = outputsByPath.find(worker.store.printStorePath(path)); + if (i != outputsByPath.end()) { + closureSize += i->second.narSize; + for (auto & ref : i->second.references) + pathsLeft.push(ref); + } else { + auto info = worker.store.queryPathInfo(path); + closureSize += info->narSize; + for (auto & ref : info->references) + pathsLeft.push(ref); + } + } + + return std::make_pair(std::move(pathsDone), closureSize); + }; + + auto applyChecks = [&](const Checks & checks) + { + if (checks.maxSize && info.narSize > *checks.maxSize) + throw BuildError("path '%s' is too large at %d bytes; limit is %d bytes", + worker.store.printStorePath(info.path), info.narSize, *checks.maxSize); + + if (checks.maxClosureSize) { + uint64_t closureSize = getClosure(info.path).second; + if (closureSize > *checks.maxClosureSize) + throw BuildError("closure of path '%s' is too large at %d bytes; limit is %d bytes", + worker.store.printStorePath(info.path), closureSize, *checks.maxClosureSize); + } + + auto checkRefs = [&](const std::optional & value, bool allowed, bool recursive) + { + if (!value) return; + + /* Parse a list of reference specifiers. Each element must + either be a store path, or the symbolic name of the output + of the derivation (such as `out'). */ + StorePathSet spec; + for (auto & i : *value) { + if (worker.store.isStorePath(i)) + spec.insert(worker.store.parseStorePath(i)); + else if (finalOutputs.count(i)) + spec.insert(finalOutputs.at(i)); + else throw BuildError("derivation contains an illegal reference specifier '%s'", i); + } + + auto used = recursive + ? getClosure(info.path).first + : info.references; + + if (recursive && checks.ignoreSelfRefs) + used.erase(info.path); + + StorePathSet badPaths; + + for (auto & i : used) + if (allowed) { + if (!spec.count(i)) + badPaths.insert(i); + } else { + if (spec.count(i)) + badPaths.insert(i); + } + + if (!badPaths.empty()) { + string badPathsStr; + for (auto & i : badPaths) { + badPathsStr += "\n "; + badPathsStr += worker.store.printStorePath(i); + } + throw BuildError("output '%s' is not allowed to refer to the following paths:%s", + worker.store.printStorePath(info.path), badPathsStr); + } + }; + + checkRefs(checks.allowedReferences, true, false); + checkRefs(checks.allowedRequisites, true, true); + checkRefs(checks.disallowedReferences, false, false); + checkRefs(checks.disallowedRequisites, false, true); + }; + + if (auto structuredAttrs = parsedDrv->getStructuredAttrs()) { + auto outputChecks = structuredAttrs->find("outputChecks"); + if (outputChecks != structuredAttrs->end()) { + auto output = outputChecks->find(outputName); + + if (output != outputChecks->end()) { + Checks checks; + + auto maxSize = output->find("maxSize"); + if (maxSize != output->end()) + checks.maxSize = maxSize->get(); + + auto maxClosureSize = output->find("maxClosureSize"); + if (maxClosureSize != output->end()) + checks.maxClosureSize = maxClosureSize->get(); + + auto get = [&](const std::string & name) -> std::optional { + auto i = output->find(name); + if (i != output->end()) { + Strings res; + for (auto j = i->begin(); j != i->end(); ++j) { + if (!j->is_string()) + throw Error("attribute '%s' of derivation '%s' must be a list of strings", name, worker.store.printStorePath(drvPath)); + res.push_back(j->get()); + } + checks.disallowedRequisites = res; + return res; + } + return {}; + }; + + checks.allowedReferences = get("allowedReferences"); + checks.allowedRequisites = get("allowedRequisites"); + checks.disallowedReferences = get("disallowedReferences"); + checks.disallowedRequisites = get("disallowedRequisites"); + + applyChecks(checks); + } + } + } else { + // legacy non-structured-attributes case + Checks checks; + checks.ignoreSelfRefs = true; + checks.allowedReferences = parsedDrv->getStringsAttr("allowedReferences"); + checks.allowedRequisites = parsedDrv->getStringsAttr("allowedRequisites"); + checks.disallowedReferences = parsedDrv->getStringsAttr("disallowedReferences"); + checks.disallowedRequisites = parsedDrv->getStringsAttr("disallowedRequisites"); + applyChecks(checks); + } + } +} + + +Path DerivationGoal::openLogFile() +{ + logSize = 0; + + if (!settings.keepLog) return ""; + + auto baseName = std::string(baseNameOf(worker.store.printStorePath(drvPath))); + + /* Create a log file. */ + Path dir = fmt("%s/%s/%s/", worker.store.logDir, worker.store.drvsLogDir, string(baseName, 0, 2)); + createDirs(dir); + + Path logFileName = fmt("%s/%s%s", dir, string(baseName, 2), + settings.compressLog ? ".bz2" : ""); + + fdLogFile = open(logFileName.c_str(), O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0666); + if (!fdLogFile) throw SysError("creating log file '%1%'", logFileName); + + logFileSink = std::make_shared(fdLogFile.get()); + + if (settings.compressLog) + logSink = std::shared_ptr(makeCompressionSink("bzip2", *logFileSink)); + else + logSink = logFileSink; + + return logFileName; +} + + +void DerivationGoal::closeLogFile() +{ + auto logSink2 = std::dynamic_pointer_cast(logSink); + if (logSink2) logSink2->finish(); + if (logFileSink) logFileSink->flush(); + logSink = logFileSink = 0; + fdLogFile = -1; +} + + +void DerivationGoal::deleteTmpDir(bool force) +{ + if (tmpDir != "") { + /* Don't keep temporary directories for builtins because they + might have privileged stuff (like a copy of netrc). */ + if (settings.keepFailed && !force && !drv->isBuiltin()) { + printError("note: keeping build directory '%s'", tmpDir); + chmod(tmpDir.c_str(), 0755); + } + else + deletePath(tmpDir); + tmpDir = ""; + } +} + + +void DerivationGoal::handleChildOutput(int fd, const string & data) +{ + if ((hook && fd == hook->builderOut.readSide.get()) || + (!hook && fd == builderOut.readSide.get())) + { + logSize += data.size(); + if (settings.maxLogSize && logSize > settings.maxLogSize) { + killChild(); + done( + BuildResult::LogLimitExceeded, + Error("%s killed after writing more than %d bytes of log output", + getName(), settings.maxLogSize)); + return; + } + + for (auto c : data) + if (c == '\r') + currentLogLinePos = 0; + else if (c == '\n') + flushLine(); + else { + if (currentLogLinePos >= currentLogLine.size()) + currentLogLine.resize(currentLogLinePos + 1); + currentLogLine[currentLogLinePos++] = c; + } + + if (logSink) (*logSink)(data); + } + + if (hook && fd == hook->fromHook.readSide.get()) { + for (auto c : data) + if (c == '\n') { + handleJSONLogMessage(currentHookLine, worker.act, hook->activities, true); + currentHookLine.clear(); + } else + currentHookLine += c; + } +} + + +void DerivationGoal::handleEOF(int fd) +{ + if (!currentLogLine.empty()) flushLine(); + worker.wakeUp(shared_from_this()); +} + + +void DerivationGoal::flushLine() +{ + if (handleJSONLogMessage(currentLogLine, *act, builderActivities, false)) + ; + + else { + logTail.push_back(currentLogLine); + if (logTail.size() > settings.logLines) logTail.pop_front(); + + act->result(resBuildLogLine, currentLogLine); + } + + currentLogLine = ""; + currentLogLinePos = 0; +} + + +std::map> DerivationGoal::queryPartialDerivationOutputMap() +{ + if (!useDerivation || drv->type() != DerivationType::CAFloating) { + std::map> res; + for (auto & [name, output] : drv->outputs) + res.insert_or_assign(name, output.path(worker.store, drv->name, name)); + return res; + } else { + return worker.store.queryPartialDerivationOutputMap(drvPath); + } +} + +OutputPathMap DerivationGoal::queryDerivationOutputMap() +{ + if (!useDerivation || drv->type() != DerivationType::CAFloating) { + OutputPathMap res; + for (auto & [name, output] : drv->outputsAndOptPaths(worker.store)) + res.insert_or_assign(name, *output.second); + return res; + } else { + return worker.store.queryDerivationOutputMap(drvPath); + } +} + + +void DerivationGoal::checkPathValidity() +{ + bool checkHash = buildMode == bmRepair; + for (auto & i : queryPartialDerivationOutputMap()) { + InitialOutput info { + .wanted = wantOutput(i.first, wantedOutputs), + }; + if (i.second) { + auto outputPath = *i.second; + info.known = { + .path = outputPath, + .status = !worker.store.isValidPath(outputPath) + ? PathStatus::Absent + : !checkHash || worker.pathContentsGood(outputPath) + ? PathStatus::Valid + : PathStatus::Corrupt, + }; + } + initialOutputs.insert_or_assign(i.first, info); + } +} + + +StorePath DerivationGoal::makeFallbackPath(std::string_view outputName) +{ + return worker.store.makeStorePath( + "rewrite:" + std::string(drvPath.to_string()) + ":name:" + std::string(outputName), + Hash(htSHA256), outputPathName(drv->name, outputName)); +} + + +StorePath DerivationGoal::makeFallbackPath(const StorePath & path) +{ + return worker.store.makeStorePath( + "rewrite:" + std::string(drvPath.to_string()) + ":" + std::string(path.to_string()), + Hash(htSHA256), path.name()); +} + + +void DerivationGoal::done(BuildResult::Status status, std::optional ex) +{ + result.status = status; + if (ex) + result.errorMsg = ex->what(); + amDone(result.success() ? ecSuccess : ecFailed, ex); + if (result.status == BuildResult::TimedOut) + worker.timedOut = true; + if (result.status == BuildResult::PermanentFailure) + worker.permanentFailure = true; + + mcExpectedBuilds.reset(); + mcRunningBuilds.reset(); + + if (result.success()) { + if (status == BuildResult::Built) + worker.doneBuilds++; + } else { + if (status != BuildResult::DependencyFailed) + worker.failedBuilds++; + } + + worker.updateProgress(); +} + + +////////////////////////////////////////////////////////////////////// + + +class SubstitutionGoal : public Goal +{ + friend class Worker; + +private: + /* The store path that should be realised through a substitute. */ + StorePath storePath; + + /* The path the substituter refers to the path as. This will be + * different when the stores have different names. */ + std::optional subPath; + + /* The remaining substituters. */ + std::list> subs; + + /* The current substituter. */ + std::shared_ptr sub; + + /* Whether a substituter failed. */ + bool substituterFailed = false; + + /* Path info returned by the substituter's query info operation. */ + std::shared_ptr info; + + /* Pipe for the substituter's standard output. */ + Pipe outPipe; + + /* The substituter thread. */ + std::thread thr; + + std::promise promise; + + /* Whether to try to repair a valid path. */ + RepairFlag repair; + + /* Location where we're downloading the substitute. Differs from + storePath when doing a repair. */ + Path destPath; + + std::unique_ptr> maintainExpectedSubstitutions, + maintainRunningSubstitutions, maintainExpectedNar, maintainExpectedDownload; + + typedef void (SubstitutionGoal::*GoalState)(); + GoalState state; + + /* Content address for recomputing store path */ + std::optional ca; + +public: + SubstitutionGoal(const StorePath & storePath, Worker & worker, RepairFlag repair = NoRepair, std::optional ca = std::nullopt); + ~SubstitutionGoal(); + + void timedOut(Error && ex) override { abort(); }; + + string key() override + { + /* "a$" ensures substitution goals happen before derivation + goals. */ + return "a$" + std::string(storePath.name()) + "$" + worker.store.printStorePath(storePath); + } + + void work() override; + + /* The states. */ + void init(); + void tryNext(); + void gotInfo(); + void referencesValid(); + void tryToRun(); + void finished(); + + /* Callback used by the worker to write to the log. */ + void handleChildOutput(int fd, const string & data) override; + void handleEOF(int fd) override; + + StorePath getStorePath() { return storePath; } +}; + + +SubstitutionGoal::SubstitutionGoal(const StorePath & storePath, Worker & worker, RepairFlag repair, std::optional ca) + : Goal(worker) + , storePath(storePath) + , repair(repair) + , ca(ca) +{ + state = &SubstitutionGoal::init; + name = fmt("substitution of '%s'", worker.store.printStorePath(this->storePath)); + trace("created"); + maintainExpectedSubstitutions = std::make_unique>(worker.expectedSubstitutions); +} + + +SubstitutionGoal::~SubstitutionGoal() +{ + try { + if (thr.joinable()) { + // FIXME: signal worker thread to quit. + thr.join(); + worker.childTerminated(this); + } + } catch (...) { + ignoreException(); + } +} + + +void SubstitutionGoal::work() +{ + (this->*state)(); +} + + +void SubstitutionGoal::init() +{ + trace("init"); + + worker.store.addTempRoot(storePath); + + /* If the path already exists we're done. */ + if (!repair && worker.store.isValidPath(storePath)) { + amDone(ecSuccess); + return; + } + + if (settings.readOnlyMode) + throw Error("cannot substitute path '%s' - no write access to the Nix store", worker.store.printStorePath(storePath)); + + subs = settings.useSubstitutes ? getDefaultSubstituters() : std::list>(); + + tryNext(); +} + + +void SubstitutionGoal::tryNext() +{ + trace("trying next substituter"); + + if (subs.size() == 0) { + /* None left. Terminate this goal and let someone else deal + with it. */ + debug("path '%s' is required, but there is no substituter that can build it", worker.store.printStorePath(storePath)); + + /* Hack: don't indicate failure if there were no substituters. + In that case the calling derivation should just do a + build. */ + amDone(substituterFailed ? ecFailed : ecNoSubstituters); + + if (substituterFailed) { + worker.failedSubstitutions++; + worker.updateProgress(); + } + + return; + } + + sub = subs.front(); + subs.pop_front(); + + if (ca) { + subPath = sub->makeFixedOutputPathFromCA(storePath.name(), *ca); + if (sub->storeDir == worker.store.storeDir) + assert(subPath == storePath); + } else if (sub->storeDir != worker.store.storeDir) { + tryNext(); + return; + } + + try { + // FIXME: make async + info = sub->queryPathInfo(subPath ? *subPath : storePath); + } catch (InvalidPath &) { + tryNext(); + return; + } catch (SubstituterDisabled &) { + if (settings.tryFallback) { + tryNext(); + return; + } + throw; + } catch (Error & e) { + if (settings.tryFallback) { + logError(e.info()); + tryNext(); + return; + } + throw; + } + + if (info->path != storePath) { + if (info->isContentAddressed(*sub) && info->references.empty()) { + auto info2 = std::make_shared(*info); + info2->path = storePath; + info = info2; + } else { + printError("asked '%s' for '%s' but got '%s'", + sub->getUri(), worker.store.printStorePath(storePath), sub->printStorePath(info->path)); + tryNext(); + return; + } + } + + /* Update the total expected download size. */ + auto narInfo = std::dynamic_pointer_cast(info); + + maintainExpectedNar = std::make_unique>(worker.expectedNarSize, info->narSize); + + maintainExpectedDownload = + narInfo && narInfo->fileSize + ? std::make_unique>(worker.expectedDownloadSize, narInfo->fileSize) + : nullptr; + + worker.updateProgress(); + + /* Bail out early if this substituter lacks a valid + signature. LocalStore::addToStore() also checks for this, but + only after we've downloaded the path. */ + if (worker.store.requireSigs + && !sub->isTrusted + && !info->checkSignatures(worker.store, worker.store.getPublicKeys())) + { + logWarning({ + .name = "Invalid path signature", + .hint = hintfmt("substituter '%s' does not have a valid signature for path '%s'", + sub->getUri(), worker.store.printStorePath(storePath)) + }); + tryNext(); + return; + } + + /* To maintain the closure invariant, we first have to realise the + paths referenced by this one. */ + for (auto & i : info->references) + if (i != storePath) /* ignore self-references */ + addWaitee(worker.makeSubstitutionGoal(i)); + + if (waitees.empty()) /* to prevent hang (no wake-up event) */ + referencesValid(); + else + state = &SubstitutionGoal::referencesValid; +} + + +void SubstitutionGoal::referencesValid() +{ + trace("all references realised"); + + if (nrFailed > 0) { + debug("some references of path '%s' could not be realised", worker.store.printStorePath(storePath)); + amDone(nrNoSubstituters > 0 || nrIncompleteClosure > 0 ? ecIncompleteClosure : ecFailed); + return; + } + + for (auto & i : info->references) + if (i != storePath) /* ignore self-references */ + assert(worker.store.isValidPath(i)); + + state = &SubstitutionGoal::tryToRun; + worker.wakeUp(shared_from_this()); +} + + +void SubstitutionGoal::tryToRun() +{ + trace("trying to run"); + + /* Make sure that we are allowed to start a build. Note that even + if maxBuildJobs == 0 (no local builds allowed), we still allow + a substituter to run. This is because substitutions cannot be + distributed to another machine via the build hook. */ + if (worker.getNrLocalBuilds() >= std::max(1U, (unsigned int) settings.maxBuildJobs)) { + worker.waitForBuildSlot(shared_from_this()); + return; + } + + maintainRunningSubstitutions = std::make_unique>(worker.runningSubstitutions); + worker.updateProgress(); + + outPipe.create(); + + promise = std::promise(); + + thr = std::thread([this]() { + try { + /* Wake up the worker loop when we're done. */ + Finally updateStats([this]() { outPipe.writeSide = -1; }); + + Activity act(*logger, actSubstitute, Logger::Fields{worker.store.printStorePath(storePath), sub->getUri()}); + PushActivity pact(act.id); + + copyStorePath(ref(sub), ref(worker.store.shared_from_this()), + subPath ? *subPath : storePath, repair, sub->isTrusted ? NoCheckSigs : CheckSigs); + + promise.set_value(); + } catch (...) { + promise.set_exception(std::current_exception()); + } + }); + + worker.childStarted(shared_from_this(), {outPipe.readSide.get()}, true, false); + + state = &SubstitutionGoal::finished; +} + + +void SubstitutionGoal::finished() +{ + trace("substitute finished"); + + thr.join(); + worker.childTerminated(this); + + try { + promise.get_future().get(); + } catch (std::exception & e) { + printError(e.what()); + + /* Cause the parent build to fail unless --fallback is given, + or the substitute has disappeared. The latter case behaves + the same as the substitute never having existed in the + first place. */ + try { + throw; + } catch (SubstituteGone &) { + } catch (...) { + substituterFailed = true; + } + + /* Try the next substitute. */ + state = &SubstitutionGoal::tryNext; + worker.wakeUp(shared_from_this()); + return; + } + + worker.markContentsGood(storePath); + + printMsg(lvlChatty, "substitution of path '%s' succeeded", worker.store.printStorePath(storePath)); + + maintainRunningSubstitutions.reset(); + + maintainExpectedSubstitutions.reset(); + worker.doneSubstitutions++; + + if (maintainExpectedDownload) { + auto fileSize = maintainExpectedDownload->delta; + maintainExpectedDownload.reset(); + worker.doneDownloadSize += fileSize; + } + + worker.doneNarSize += maintainExpectedNar->delta; + maintainExpectedNar.reset(); + + worker.updateProgress(); + + amDone(ecSuccess); +} + + +void SubstitutionGoal::handleChildOutput(int fd, const string & data) +{ +} + + +void SubstitutionGoal::handleEOF(int fd) +{ + if (fd == outPipe.readSide.get()) worker.wakeUp(shared_from_this()); +} + +////////////////////////////////////////////////////////////////////// + + +Worker::Worker(LocalStore & store) + : act(*logger, actRealise) + , actDerivations(*logger, actBuilds) + , actSubstitutions(*logger, actCopyPaths) + , store(store) +{ + /* Debugging: prevent recursive workers. */ + nrLocalBuilds = 0; + lastWokenUp = steady_time_point::min(); + permanentFailure = false; + timedOut = false; + hashMismatch = false; + checkMismatch = false; +} + + +Worker::~Worker() +{ + /* Explicitly get rid of all strong pointers now. After this all + goals that refer to this worker should be gone. (Otherwise we + are in trouble, since goals may call childTerminated() etc. in + their destructors). */ + topGoals.clear(); + + assert(expectedSubstitutions == 0); + assert(expectedDownloadSize == 0); + assert(expectedNarSize == 0); +} + + +std::shared_ptr Worker::makeDerivationGoalCommon( + const StorePath & drvPath, + const StringSet & wantedOutputs, + std::function()> mkDrvGoal) +{ + WeakGoalPtr & abstract_goal_weak = derivationGoals[drvPath]; + GoalPtr abstract_goal = abstract_goal_weak.lock(); // FIXME + std::shared_ptr goal; + if (!abstract_goal) { + goal = mkDrvGoal(); + abstract_goal_weak = goal; + wakeUp(goal); + } else { + goal = std::dynamic_pointer_cast(abstract_goal); + assert(goal); + goal->addWantedOutputs(wantedOutputs); + } + return goal; +} + + +std::shared_ptr Worker::makeDerivationGoal(const StorePath & drvPath, + const StringSet & wantedOutputs, BuildMode buildMode) +{ + return makeDerivationGoalCommon(drvPath, wantedOutputs, [&]() { + return std::make_shared(drvPath, wantedOutputs, *this, buildMode); + }); +} + + +std::shared_ptr Worker::makeBasicDerivationGoal(const StorePath & drvPath, + const BasicDerivation & drv, const StringSet & wantedOutputs, BuildMode buildMode) +{ + return makeDerivationGoalCommon(drvPath, wantedOutputs, [&]() { + return std::make_shared(drvPath, drv, wantedOutputs, *this, buildMode); + }); +} + + +GoalPtr Worker::makeSubstitutionGoal(const StorePath & path, RepairFlag repair, std::optional ca) +{ + WeakGoalPtr & goal_weak = substitutionGoals[path]; + GoalPtr goal = goal_weak.lock(); // FIXME + if (!goal) { + goal = std::make_shared(path, *this, repair, ca); + goal_weak = goal; + wakeUp(goal); + } + return goal; +} + + +static void removeGoal(GoalPtr goal, WeakGoalMap & goalMap) +{ + /* !!! inefficient */ + for (WeakGoalMap::iterator i = goalMap.begin(); + i != goalMap.end(); ) + if (i->second.lock() == goal) { + WeakGoalMap::iterator j = i; ++j; + goalMap.erase(i); + i = j; + } + else ++i; +} + + +void Worker::removeGoal(GoalPtr goal) +{ + nix::removeGoal(goal, derivationGoals); + nix::removeGoal(goal, substitutionGoals); + if (topGoals.find(goal) != topGoals.end()) { + topGoals.erase(goal); + /* If a top-level goal failed, then kill all other goals + (unless keepGoing was set). */ + if (goal->exitCode == Goal::ecFailed && !settings.keepGoing) + topGoals.clear(); + } + + /* Wake up goals waiting for any goal to finish. */ + for (auto & i : waitingForAnyGoal) { + GoalPtr goal = i.lock(); + if (goal) wakeUp(goal); + } + + waitingForAnyGoal.clear(); +} + + +void Worker::wakeUp(GoalPtr goal) +{ + goal->trace("woken up"); + addToWeakGoals(awake, goal); +} + + +unsigned Worker::getNrLocalBuilds() +{ + return nrLocalBuilds; +} + + +void Worker::childStarted(GoalPtr goal, const set & fds, + bool inBuildSlot, bool respectTimeouts) +{ + Child child; + child.goal = goal; + child.goal2 = goal.get(); + child.fds = fds; + child.timeStarted = child.lastOutput = steady_time_point::clock::now(); + child.inBuildSlot = inBuildSlot; + child.respectTimeouts = respectTimeouts; + children.emplace_back(child); + if (inBuildSlot) nrLocalBuilds++; +} + + +void Worker::childTerminated(Goal * goal, bool wakeSleepers) +{ + auto i = std::find_if(children.begin(), children.end(), + [&](const Child & child) { return child.goal2 == goal; }); + if (i == children.end()) return; + + if (i->inBuildSlot) { + assert(nrLocalBuilds > 0); + nrLocalBuilds--; + } + + children.erase(i); + + if (wakeSleepers) { + + /* Wake up goals waiting for a build slot. */ + for (auto & j : wantingToBuild) { + GoalPtr goal = j.lock(); + if (goal) wakeUp(goal); + } + + wantingToBuild.clear(); + } +} + + +void Worker::waitForBuildSlot(GoalPtr goal) +{ + debug("wait for build slot"); + if (getNrLocalBuilds() < settings.maxBuildJobs) + wakeUp(goal); /* we can do it right away */ + else + addToWeakGoals(wantingToBuild, goal); +} + + +void Worker::waitForAnyGoal(GoalPtr goal) +{ + debug("wait for any goal"); + addToWeakGoals(waitingForAnyGoal, goal); +} + + +void Worker::waitForAWhile(GoalPtr goal) +{ + debug("wait for a while"); + addToWeakGoals(waitingForAWhile, goal); +} + + +void Worker::run(const Goals & _topGoals) +{ + for (auto & i : _topGoals) topGoals.insert(i); + + debug("entered goal loop"); + + while (1) { + + checkInterrupt(); + + store.autoGC(false); + + /* Call every wake goal (in the ordering established by + CompareGoalPtrs). */ + while (!awake.empty() && !topGoals.empty()) { + Goals awake2; + for (auto & i : awake) { + GoalPtr goal = i.lock(); + if (goal) awake2.insert(goal); + } + awake.clear(); + for (auto & goal : awake2) { + checkInterrupt(); + goal->work(); + if (topGoals.empty()) break; // stuff may have been cancelled + } + } + + if (topGoals.empty()) break; + + /* Wait for input. */ + if (!children.empty() || !waitingForAWhile.empty()) + waitForInput(); + else { + if (awake.empty() && 0 == settings.maxBuildJobs) + { + if (getMachines().empty()) + throw Error("unable to start any build; either increase '--max-jobs' " + "or enable remote builds." + "\nhttps://nixos.org/nix/manual/#chap-distributed-builds"); + else + throw Error("unable to start any build; remote machines may not have " + "all required system features." + "\nhttps://nixos.org/nix/manual/#chap-distributed-builds"); + + } + assert(!awake.empty()); + } + } + + /* If --keep-going is not set, it's possible that the main goal + exited while some of its subgoals were still active. But if + --keep-going *is* set, then they must all be finished now. */ + assert(!settings.keepGoing || awake.empty()); + assert(!settings.keepGoing || wantingToBuild.empty()); + assert(!settings.keepGoing || children.empty()); +} + +void Worker::waitForInput() +{ + printMsg(lvlVomit, "waiting for children"); + + /* Process output from the file descriptors attached to the + children, namely log output and output path creation commands. + We also use this to detect child termination: if we get EOF on + the logger pipe of a build, we assume that the builder has + terminated. */ + + bool useTimeout = false; + long timeout = 0; + auto before = steady_time_point::clock::now(); + + /* If we're monitoring for silence on stdout/stderr, or if there + is a build timeout, then wait for input until the first + deadline for any child. */ + auto nearest = steady_time_point::max(); // nearest deadline + if (settings.minFree.get() != 0) + // Periodicallty wake up to see if we need to run the garbage collector. + nearest = before + std::chrono::seconds(10); + for (auto & i : children) { + if (!i.respectTimeouts) continue; + if (0 != settings.maxSilentTime) + nearest = std::min(nearest, i.lastOutput + std::chrono::seconds(settings.maxSilentTime)); + if (0 != settings.buildTimeout) + nearest = std::min(nearest, i.timeStarted + std::chrono::seconds(settings.buildTimeout)); + } + if (nearest != steady_time_point::max()) { + timeout = std::max(1L, (long) std::chrono::duration_cast(nearest - before).count()); + useTimeout = true; + } + + /* If we are polling goals that are waiting for a lock, then wake + up after a few seconds at most. */ + if (!waitingForAWhile.empty()) { + useTimeout = true; + if (lastWokenUp == steady_time_point::min() || lastWokenUp > before) lastWokenUp = before; + timeout = std::max(1L, + (long) std::chrono::duration_cast( + lastWokenUp + std::chrono::seconds(settings.pollInterval) - before).count()); + } else lastWokenUp = steady_time_point::min(); + + if (useTimeout) + vomit("sleeping %d seconds", timeout); + + /* Use select() to wait for the input side of any logger pipe to + become `available'. Note that `available' (i.e., non-blocking) + includes EOF. */ + std::vector pollStatus; + std::map fdToPollStatus; + for (auto & i : children) { + for (auto & j : i.fds) { + pollStatus.push_back((struct pollfd) { .fd = j, .events = POLLIN }); + fdToPollStatus[j] = pollStatus.size() - 1; + } + } + + if (poll(pollStatus.data(), pollStatus.size(), + useTimeout ? timeout * 1000 : -1) == -1) { + if (errno == EINTR) return; + throw SysError("waiting for input"); + } + + auto after = steady_time_point::clock::now(); + + /* Process all available file descriptors. FIXME: this is + O(children * fds). */ + decltype(children)::iterator i; + for (auto j = children.begin(); j != children.end(); j = i) { + i = std::next(j); + + checkInterrupt(); + + GoalPtr goal = j->goal.lock(); + assert(goal); + + set fds2(j->fds); + std::vector buffer(4096); + for (auto & k : fds2) { + if (pollStatus.at(fdToPollStatus.at(k)).revents) { + ssize_t rd = ::read(k, buffer.data(), buffer.size()); + // FIXME: is there a cleaner way to handle pt close + // than EIO? Is this even standard? + if (rd == 0 || (rd == -1 && errno == EIO)) { + debug("%1%: got EOF", goal->getName()); + goal->handleEOF(k); + j->fds.erase(k); + } else if (rd == -1) { + if (errno != EINTR) + throw SysError("%s: read failed", goal->getName()); + } else { + printMsg(lvlVomit, "%1%: read %2% bytes", + goal->getName(), rd); + string data((char *) buffer.data(), rd); + j->lastOutput = after; + goal->handleChildOutput(k, data); + } + } + } + + if (goal->exitCode == Goal::ecBusy && + 0 != settings.maxSilentTime && + j->respectTimeouts && + after - j->lastOutput >= std::chrono::seconds(settings.maxSilentTime)) + { + goal->timedOut(Error( + "%1% timed out after %2% seconds of silence", + goal->getName(), settings.maxSilentTime)); + } + + else if (goal->exitCode == Goal::ecBusy && + 0 != settings.buildTimeout && + j->respectTimeouts && + after - j->timeStarted >= std::chrono::seconds(settings.buildTimeout)) + { + goal->timedOut(Error( + "%1% timed out after %2% seconds", + goal->getName(), settings.buildTimeout)); + } + } + + if (!waitingForAWhile.empty() && lastWokenUp + std::chrono::seconds(settings.pollInterval) <= after) { + lastWokenUp = after; + for (auto & i : waitingForAWhile) { + GoalPtr goal = i.lock(); + if (goal) wakeUp(goal); + } + waitingForAWhile.clear(); + } +} + + +unsigned int Worker::exitStatus() +{ + /* + * 1100100 + * ^^^^ + * |||`- timeout + * ||`-- output hash mismatch + * |`--- build failure + * `---- not deterministic + */ + unsigned int mask = 0; + bool buildFailure = permanentFailure || timedOut || hashMismatch; + if (buildFailure) + mask |= 0x04; // 100 + if (timedOut) + mask |= 0x01; // 101 + if (hashMismatch) + mask |= 0x02; // 102 + if (checkMismatch) { + mask |= 0x08; // 104 + } + + if (mask) + mask |= 0x60; + return mask ? mask : 1; +} + + +bool Worker::pathContentsGood(const StorePath & path) +{ + auto i = pathContentsGoodCache.find(path); + if (i != pathContentsGoodCache.end()) return i->second; + printInfo("checking path '%s'...", store.printStorePath(path)); + auto info = store.queryPathInfo(path); + bool res; + if (!pathExists(store.printStorePath(path))) + res = false; + else { + HashResult current = hashPath(info->narHash.type, store.printStorePath(path)); + Hash nullHash(htSHA256); + res = info->narHash == nullHash || info->narHash == current.first; + } + pathContentsGoodCache.insert_or_assign(path, res); + if (!res) + logError({ + .name = "Corrupted path", + .hint = hintfmt("path '%s' is corrupted or missing!", store.printStorePath(path)) + }); + return res; +} + + +void Worker::markContentsGood(const StorePath & path) +{ + pathContentsGoodCache.insert_or_assign(path, true); +} + + +////////////////////////////////////////////////////////////////////// + + +static void primeCache(Store & store, const std::vector & paths) +{ + StorePathSet willBuild, willSubstitute, unknown; + uint64_t downloadSize, narSize; + store.queryMissing(paths, willBuild, willSubstitute, unknown, downloadSize, narSize); + + if (!willBuild.empty() && 0 == settings.maxBuildJobs && getMachines().empty()) + throw Error( + "%d derivations need to be built, but neither local builds ('--max-jobs') " + "nor remote builds ('--builders') are enabled", willBuild.size()); +} + + +void LocalStore::buildPaths(const std::vector & drvPaths, BuildMode buildMode) +{ + Worker worker(*this); + + primeCache(*this, drvPaths); + + Goals goals; + for (auto & path : drvPaths) { + if (path.path.isDerivation()) + goals.insert(worker.makeDerivationGoal(path.path, path.outputs, buildMode)); + else + goals.insert(worker.makeSubstitutionGoal(path.path, buildMode == bmRepair ? Repair : NoRepair)); + } + + worker.run(goals); + + StorePathSet failed; + std::optional ex; + for (auto & i : goals) { + if (i->ex) { + if (ex) + logError(i->ex->info()); + else + ex = i->ex; + } + if (i->exitCode != Goal::ecSuccess) { + DerivationGoal * i2 = dynamic_cast(i.get()); + if (i2) failed.insert(i2->getDrvPath()); + else failed.insert(dynamic_cast(i.get())->getStorePath()); + } + } + + if (failed.size() == 1 && ex) { + ex->status = worker.exitStatus(); + throw *ex; + } else if (!failed.empty()) { + if (ex) logError(ex->info()); + throw Error(worker.exitStatus(), "build of %s failed", showPaths(failed)); + } +} + +BuildResult LocalStore::buildDerivation(const StorePath & drvPath, const BasicDerivation & drv, + BuildMode buildMode) +{ + Worker worker(*this); + auto goal = worker.makeBasicDerivationGoal(drvPath, drv, {}, buildMode); + + BuildResult result; + + try { + worker.run(Goals{goal}); + result = goal->getResult(); + } catch (Error & e) { + result.status = BuildResult::MiscFailure; + result.errorMsg = e.msg(); + } + + return result; +} + + +void LocalStore::ensurePath(const StorePath & path) +{ + /* If the path is already valid, we're done. */ + if (isValidPath(path)) return; + + primeCache(*this, {{path}}); + + Worker worker(*this); + GoalPtr goal = worker.makeSubstitutionGoal(path); + Goals goals = {goal}; + + worker.run(goals); + + if (goal->exitCode != Goal::ecSuccess) { + if (goal->ex) { + goal->ex->status = worker.exitStatus(); + throw *goal->ex; + } else + throw Error(worker.exitStatus(), "path '%s' does not exist and cannot be created", printStorePath(path)); + } +} + + +void LocalStore::repairPath(const StorePath & path) +{ + Worker worker(*this); + GoalPtr goal = worker.makeSubstitutionGoal(path, Repair); + Goals goals = {goal}; + + worker.run(goals); + + if (goal->exitCode != Goal::ecSuccess) { + /* Since substituting the path didn't work, if we have a valid + deriver, then rebuild the deriver. */ + auto info = queryPathInfo(path); + if (info->deriver && isValidPath(*info->deriver)) { + goals.clear(); + goals.insert(worker.makeDerivationGoal(*info->deriver, StringSet(), bmRepair)); + worker.run(goals); + } else + throw Error(worker.exitStatus(), "cannot repair path '%s'", printStorePath(path)); + } +} + + +} -- cgit v1.2.3