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#include "gc-store.hh"
#include "signals.hh"
#include "platform/linux.hh"
#include <regex>
namespace nix {
static RegisterStoreImplementation<LinuxLocalStore, LocalStoreConfig> regLocalStore;
static void readProcLink(const std::string & file, UncheckedRoots & roots)
{
constexpr auto bufsiz = PATH_MAX;
char buf[bufsiz];
auto res = readlink(file.c_str(), buf, bufsiz);
if (res == -1) {
if (errno == ENOENT || errno == EACCES || errno == ESRCH) {
return;
}
throw SysError("reading symlink");
}
if (res == bufsiz) {
throw Error("overly long symlink starting with '%1%'", std::string_view(buf, bufsiz));
}
if (res > 0 && buf[0] == '/') {
roots[std::string(static_cast<char *>(buf), res)].emplace(file);
}
}
static std::string quoteRegexChars(const std::string & raw)
{
static auto specialRegex = std::regex(R"([.^$\\*+?()\[\]{}|])");
return std::regex_replace(raw, specialRegex, R"(\$&)");
}
static void readFileRoots(const char * path, UncheckedRoots & roots)
{
try {
roots[readFile(path)].emplace(path);
} catch (SysError & e) {
if (e.errNo != ENOENT && e.errNo != EACCES) {
throw;
}
}
}
void LinuxLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
{
auto procDir = AutoCloseDir{opendir("/proc")};
if (procDir) {
struct dirent * ent;
auto digitsRegex = std::regex(R"(^\d+$)");
auto mapRegex = std::regex(R"(^\s*\S+\s+\S+\s+\S+\s+\S+\s+\S+\s+(/\S+)\s*$)");
auto storePathRegex =
std::regex(quoteRegexChars(storeDir) + R"(/[0-9a-z]+[0-9a-zA-Z\+\-\._\?=]*)");
while (errno = 0, ent = readdir(procDir.get())) {
checkInterrupt();
if (std::regex_match(ent->d_name, digitsRegex)) {
try {
readProcLink(fmt("/proc/%s/exe", ent->d_name), unchecked);
readProcLink(fmt("/proc/%s/cwd", ent->d_name), unchecked);
auto fdStr = fmt("/proc/%s/fd", ent->d_name);
auto fdDir = AutoCloseDir(opendir(fdStr.c_str()));
if (!fdDir) {
if (errno == ENOENT || errno == EACCES) {
continue;
}
throw SysError("opening %1%", fdStr);
}
struct dirent * fd_ent;
while (errno = 0, fd_ent = readdir(fdDir.get())) {
if (fd_ent->d_name[0] != '.') {
readProcLink(fmt("%s/%s", fdStr, fd_ent->d_name), unchecked);
}
}
if (errno) {
if (errno == ESRCH) {
continue;
}
throw SysError("iterating /proc/%1%/fd", ent->d_name);
}
fdDir.reset();
auto mapFile = fmt("/proc/%s/maps", ent->d_name);
auto mapLines =
tokenizeString<std::vector<std::string>>(readFile(mapFile), "\n");
for (const auto & line : mapLines) {
auto match = std::smatch{};
if (std::regex_match(line, match, mapRegex)) {
unchecked[match[1]].emplace(mapFile);
}
}
auto envFile = fmt("/proc/%s/environ", ent->d_name);
auto envString = readFile(envFile);
auto env_end = std::sregex_iterator{};
for (auto i =
std::sregex_iterator{
envString.begin(), envString.end(), storePathRegex
};
i != env_end;
++i)
{
unchecked[i->str()].emplace(envFile);
}
} catch (SysError & e) {
if (errno == ENOENT || errno == EACCES || errno == ESRCH) {
continue;
}
throw;
}
}
}
if (errno) {
throw SysError("iterating /proc");
}
}
readFileRoots("/proc/sys/kernel/modprobe", unchecked);
readFileRoots("/proc/sys/kernel/fbsplash", unchecked);
readFileRoots("/proc/sys/kernel/poweroff_cmd", unchecked);
}
}
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