diff options
Diffstat (limited to 'src/libstore/derivations.cc')
| -rw-r--r-- | src/libstore/derivations.cc | 371 |
1 files changed, 269 insertions, 102 deletions
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc index f325e511a..a9fed2564 100644 --- a/src/libstore/derivations.cc +++ b/src/libstore/derivations.cc @@ -7,12 +7,51 @@ namespace nix { -const StorePath & BasicDerivation::findOutput(const string & id) const +std::optional<StorePath> DerivationOutput::pathOpt(const Store & store, std::string_view drvName) const { - auto i = outputs.find(id); - if (i == outputs.end()) - throw Error("derivation has no output '%s'", id); - return i->second.path; + return std::visit(overloaded { + [](DerivationOutputInputAddressed doi) -> std::optional<StorePath> { + return { doi.path }; + }, + [&](DerivationOutputCAFixed dof) -> std::optional<StorePath> { + return { + store.makeFixedOutputPath(dof.hash.method, dof.hash.hash, drvName) + }; + }, + [](DerivationOutputCAFloating dof) -> std::optional<StorePath> { + return std::nullopt; + }, + }, output); +} + + +bool derivationIsCA(DerivationType dt) { + switch (dt) { + case DerivationType::InputAddressed: return false; + case DerivationType::CAFixed: return true; + case DerivationType::CAFloating: return true; + }; + // Since enums can have non-variant values, but making a `default:` would + // disable exhaustiveness warnings. + assert(false); +} + +bool derivationIsFixed(DerivationType dt) { + switch (dt) { + case DerivationType::InputAddressed: return false; + case DerivationType::CAFixed: return true; + case DerivationType::CAFloating: return false; + }; + assert(false); +} + +bool derivationIsImpure(DerivationType dt) { + switch (dt) { + case DerivationType::InputAddressed: return false; + case DerivationType::CAFixed: return true; + case DerivationType::CAFloating: return false; + }; + assert(false); } @@ -23,7 +62,7 @@ bool BasicDerivation::isBuiltin() const StorePath writeDerivation(ref<Store> store, - const Derivation & drv, std::string_view name, RepairFlag repair) + const Derivation & drv, RepairFlag repair) { auto references = drv.inputSrcs; for (auto & i : drv.inputDrvs) @@ -31,7 +70,7 @@ StorePath writeDerivation(ref<Store> store, /* Note that the outputs of a derivation are *not* references (that can be missing (of course) and should not necessarily be held during a garbage collection). */ - auto suffix = std::string(name) + drvExtension; + auto suffix = std::string(drv.name) + drvExtension; auto contents = drv.unparse(*store, false); return settings.readOnlyMode ? store->computeStorePathForText(suffix, contents, references) @@ -100,37 +139,57 @@ static StringSet parseStrings(std::istream & str, bool arePaths) } -static DerivationOutput parseDerivationOutput(const Store & store, std::istringstream & str) +static DerivationOutput parseDerivationOutput(const Store & store, + StorePath path, std::string_view hashAlgo, std::string_view hash) { - expect(str, ","); auto path = store.parseStorePath(parsePath(str)); - expect(str, ","); auto hashAlgo = parseString(str); - expect(str, ","); const auto hash = parseString(str); - expect(str, ")"); - - std::optional<FixedOutputHash> fsh; if (hashAlgo != "") { auto method = FileIngestionMethod::Flat; if (string(hashAlgo, 0, 2) == "r:") { method = FileIngestionMethod::Recursive; - hashAlgo = string(hashAlgo, 2); + hashAlgo = hashAlgo.substr(2); } const HashType hashType = parseHashType(hashAlgo); - fsh = FixedOutputHash { - .method = std::move(method), - .hash = Hash(hash, hashType), + + return hash != "" + ? DerivationOutput { + .output = DerivationOutputCAFixed { + .hash = FixedOutputHash { + .method = std::move(method), + .hash = Hash::parseNonSRIUnprefixed(hash, hashType), + }, + } + } + : (settings.requireExperimentalFeature("ca-derivations"), + DerivationOutput { + .output = DerivationOutputCAFloating { + .method = std::move(method), + .hashType = std::move(hashType), + }, + }); + } else + return DerivationOutput { + .output = DerivationOutputInputAddressed { + .path = std::move(path), + } }; - } +} - return DerivationOutput { - .path = std::move(path), - .hash = std::move(fsh), - }; +static DerivationOutput parseDerivationOutput(const Store & store, std::istringstream & str) +{ + expect(str, ","); auto path = store.parseStorePath(parsePath(str)); + expect(str, ","); const auto hashAlgo = parseString(str); + expect(str, ","); const auto hash = parseString(str); + expect(str, ")"); + + return parseDerivationOutput(store, std::move(path), hashAlgo, hash); } -static Derivation parseDerivation(const Store & store, std::string && s) +static Derivation parseDerivation(const Store & store, std::string && s, std::string_view name) { Derivation drv; + drv.name = name; + std::istringstream str(std::move(s)); expect(str, "Derive(["); @@ -174,10 +233,10 @@ static Derivation parseDerivation(const Store & store, std::string && s) } -Derivation readDerivation(const Store & store, const Path & drvPath) +Derivation readDerivation(const Store & store, const Path & drvPath, std::string_view name) { try { - return parseDerivation(store, readFile(drvPath)); + return parseDerivation(store, readFile(drvPath), name); } catch (FormatError & e) { throw Error("error parsing derivation '%1%': %2%", drvPath, e.msg()); } @@ -195,7 +254,7 @@ Derivation Store::readDerivation(const StorePath & drvPath) { auto accessor = getFSAccessor(); try { - return parseDerivation(*this, accessor->readFile(printStorePath(drvPath))); + return parseDerivation(*this, accessor->readFile(printStorePath(drvPath)), Derivation::nameFromPath(drvPath)); } catch (FormatError & e) { throw Error("error parsing derivation '%s': %s", printStorePath(drvPath), e.msg()); } @@ -263,10 +322,21 @@ string Derivation::unparse(const Store & store, bool maskOutputs, for (auto & i : outputs) { if (first) first = false; else s += ','; s += '('; printUnquotedString(s, i.first); - s += ','; printUnquotedString(s, maskOutputs ? "" : store.printStorePath(i.second.path)); - s += ','; printUnquotedString(s, i.second.hash ? i.second.hash->printMethodAlgo() : ""); - s += ','; printUnquotedString(s, - i.second.hash ? i.second.hash->hash.to_string(Base16, false) : ""); + s += ','; printUnquotedString(s, maskOutputs ? "" : store.printStorePath(i.second.path(store, name))); + std::visit(overloaded { + [&](DerivationOutputInputAddressed doi) { + s += ','; printUnquotedString(s, ""); + s += ','; printUnquotedString(s, ""); + }, + [&](DerivationOutputCAFixed dof) { + s += ','; printUnquotedString(s, dof.hash.printMethodAlgo()); + s += ','; printUnquotedString(s, dof.hash.hash.to_string(Base16, false)); + }, + [&](DerivationOutputCAFloating dof) { + s += ','; printUnquotedString(s, makeFileIngestionPrefix(dof.method) + printHashType(dof.hashType)); + s += ','; printUnquotedString(s, ""); + }, + }, i.second.output); s += ')'; } @@ -318,59 +388,134 @@ bool isDerivation(const string & fileName) } -bool BasicDerivation::isFixedOutput() const +DerivationType BasicDerivation::type() const { - return outputs.size() == 1 && - outputs.begin()->first == "out" && - outputs.begin()->second.hash; + std::set<std::string_view> inputAddressedOutputs, fixedCAOutputs, floatingCAOutputs; + std::optional<HashType> floatingHashType; + for (auto & i : outputs) { + std::visit(overloaded { + [&](DerivationOutputInputAddressed _) { + inputAddressedOutputs.insert(i.first); + }, + [&](DerivationOutputCAFixed _) { + fixedCAOutputs.insert(i.first); + }, + [&](DerivationOutputCAFloating dof) { + floatingCAOutputs.insert(i.first); + if (!floatingHashType) { + floatingHashType = dof.hashType; + } else { + if (*floatingHashType != dof.hashType) + throw Error("All floating outputs must use the same hash type"); + } + }, + }, i.second.output); + } + + if (inputAddressedOutputs.empty() && fixedCAOutputs.empty() && floatingCAOutputs.empty()) { + throw Error("Must have at least one output"); + } else if (! inputAddressedOutputs.empty() && fixedCAOutputs.empty() && floatingCAOutputs.empty()) { + return DerivationType::InputAddressed; + } else if (inputAddressedOutputs.empty() && ! fixedCAOutputs.empty() && floatingCAOutputs.empty()) { + if (fixedCAOutputs.size() > 1) + // FIXME: Experimental feature? + throw Error("Only one fixed output is allowed for now"); + if (*fixedCAOutputs.begin() != "out") + throw Error("Single fixed output must be named \"out\""); + return DerivationType::CAFixed; + } else if (inputAddressedOutputs.empty() && fixedCAOutputs.empty() && ! floatingCAOutputs.empty()) { + return DerivationType::CAFloating; + } else { + throw Error("Can't mix derivation output types"); + } } DrvHashes drvHashes; +/* pathDerivationModulo and hashDerivationModulo are mutually recursive + */ + +/* Look up the derivation by value and memoize the + `hashDerivationModulo` call. + */ +static const DrvHashModulo & pathDerivationModulo(Store & store, const StorePath & drvPath) +{ + auto h = drvHashes.find(drvPath); + if (h == drvHashes.end()) { + assert(store.isValidPath(drvPath)); + // Cache it + h = drvHashes.insert_or_assign( + drvPath, + hashDerivationModulo( + store, + store.readDerivation(drvPath), + false)).first; + } + return h->second; +} -/* Returns the hash of a derivation modulo fixed-output - subderivations. A fixed-output derivation is a derivation with one - output (`out') for which an expected hash and hash algorithm are - specified (using the `outputHash' and `outputHashAlgo' - attributes). We don't want changes to such derivations to - propagate upwards through the dependency graph, changing output - paths everywhere. - - For instance, if we change the url in a call to the `fetchurl' - function, we do not want to rebuild everything depending on it - (after all, (the hash of) the file being downloaded is unchanged). - So the *output paths* should not change. On the other hand, the - *derivation paths* should change to reflect the new dependency - graph. - - That's what this function does: it returns a hash which is just the - hash of the derivation ATerm, except that any input derivation - paths have been replaced by the result of a recursive call to this - function, and that for fixed-output derivations we return a hash of - its output path. */ -Hash hashDerivationModulo(Store & store, const Derivation & drv, bool maskOutputs) +/* See the header for interface details. These are the implementation details. + + For fixed-output derivations, each hash in the map is not the + corresponding output's content hash, but a hash of that hash along + with other constant data. The key point is that the value is a pure + function of the output's contents, and there are no preimage attacks + either spoofing an output's contents for a derivation, or + spoofing a derivation for an output's contents. + + For regular derivations, it looks up each subderivation from its hash + and recurs. If the subderivation is also regular, it simply + substitutes the derivation path with its hash. If the subderivation + is fixed-output, however, it takes each output hash and pretends it + is a derivation hash producing a single "out" output. This is so we + don't leak the provenance of fixed outputs, reducing pointless cache + misses as the build itself won't know this. + */ +DrvHashModulo hashDerivationModulo(Store & store, const Derivation & drv, bool maskOutputs) { /* Return a fixed hash for fixed-output derivations. */ - if (drv.isFixedOutput()) { - DerivationOutputs::const_iterator i = drv.outputs.begin(); - return hashString(htSHA256, "fixed:out:" - + i->second.hash->printMethodAlgo() + ":" - + i->second.hash->hash.to_string(Base16, false) + ":" - + store.printStorePath(i->second.path)); + switch (drv.type()) { + case DerivationType::CAFloating: + throw Error("Regular input-addressed derivations are not yet allowed to depend on CA derivations"); + case DerivationType::CAFixed: { + std::map<std::string, Hash> outputHashes; + for (const auto & i : drv.outputsAndPaths(store)) { + auto & dof = std::get<DerivationOutputCAFixed>(i.second.first.output); + auto hash = hashString(htSHA256, "fixed:out:" + + dof.hash.printMethodAlgo() + ":" + + dof.hash.hash.to_string(Base16, false) + ":" + + store.printStorePath(i.second.second)); + outputHashes.insert_or_assign(i.first, std::move(hash)); + } + return outputHashes; + } + case DerivationType::InputAddressed: + break; } /* For other derivations, replace the inputs paths with recursive - calls to this function.*/ + calls to this function. */ std::map<std::string, StringSet> inputs2; for (auto & i : drv.inputDrvs) { - auto h = drvHashes.find(i.first); - if (h == drvHashes.end()) { - assert(store.isValidPath(i.first)); - h = drvHashes.insert_or_assign(i.first, hashDerivationModulo(store, - store.readDerivation(i.first), false)).first; - } - inputs2.insert_or_assign(h->second.to_string(Base16, false), i.second); + const auto & res = pathDerivationModulo(store, i.first); + std::visit(overloaded { + // Regular non-CA derivation, replace derivation + [&](Hash drvHash) { + inputs2.insert_or_assign(drvHash.to_string(Base16, false), i.second); + }, + // CA derivation's output hashes + [&](CaOutputHashes outputHashes) { + std::set<std::string> justOut = { "out" }; + for (auto & output : i.second) { + /* Put each one in with a single "out" output.. */ + const auto h = outputHashes.at(output); + inputs2.insert_or_assign( + h.to_string(Base16, false), + justOut); + } + }, + }, res); } return hashString(htSHA256, drv.unparse(store, maskOutputs, &inputs2)); @@ -391,38 +536,21 @@ bool wantOutput(const string & output, const std::set<string> & wanted) } -StorePathSet BasicDerivation::outputPaths() const +StorePathSet BasicDerivation::outputPaths(const Store & store) const { StorePathSet paths; - for (auto & i : outputs) - paths.insert(i.second.path); + for (auto & i : outputsAndPaths(store)) + paths.insert(i.second.second); return paths; } static DerivationOutput readDerivationOutput(Source & in, const Store & store) { auto path = store.parseStorePath(readString(in)); - auto hashAlgo = readString(in); - auto hash = readString(in); - - std::optional<FixedOutputHash> fsh; - if (hashAlgo != "") { - auto method = FileIngestionMethod::Flat; - if (string(hashAlgo, 0, 2) == "r:") { - method = FileIngestionMethod::Recursive; - hashAlgo = string(hashAlgo, 2); - } - auto hashType = parseHashType(hashAlgo); - fsh = FixedOutputHash { - .method = std::move(method), - .hash = Hash(hash, hashType), - }; - } + const auto hashAlgo = readString(in); + const auto hash = readString(in); - return DerivationOutput { - .path = std::move(path), - .hash = std::move(fsh), - }; + return parseDerivationOutput(store, std::move(path), hashAlgo, hash); } StringSet BasicDerivation::outputNames() const @@ -433,9 +561,41 @@ StringSet BasicDerivation::outputNames() const return names; } +DerivationOutputsAndPaths BasicDerivation::outputsAndPaths(const Store & store) const { + DerivationOutputsAndPaths outsAndPaths; + for (auto output : outputs) + outsAndPaths.insert(std::make_pair( + output.first, + std::make_pair(output.second, output.second.path(store, name)) + ) + ); + return outsAndPaths; +} + +DerivationOutputsAndOptPaths BasicDerivation::outputsAndOptPaths(const Store & store) const { + DerivationOutputsAndOptPaths outsAndOptPaths; + for (auto output : outputs) + outsAndOptPaths.insert(std::make_pair( + output.first, + std::make_pair(output.second, output.second.pathOpt(store, output.first)) + ) + ); + return outsAndOptPaths; +} + +std::string_view BasicDerivation::nameFromPath(const StorePath & drvPath) { + auto nameWithSuffix = drvPath.name(); + constexpr std::string_view extension = ".drv"; + assert(hasSuffix(nameWithSuffix, extension)); + nameWithSuffix.remove_suffix(extension.size()); + return nameWithSuffix; +} -Source & readDerivation(Source & in, const Store & store, BasicDerivation & drv) + +Source & readDerivation(Source & in, const Store & store, BasicDerivation & drv, std::string_view name) { + drv.name = name; + drv.outputs.clear(); auto nr = readNum<size_t>(in); for (size_t n = 0; n < nr; n++) { @@ -462,15 +622,22 @@ Source & readDerivation(Source & in, const Store & store, BasicDerivation & drv) void writeDerivation(Sink & out, const Store & store, const BasicDerivation & drv) { out << drv.outputs.size(); - for (auto & i : drv.outputs) { + for (auto & i : drv.outputsAndPaths(store)) { out << i.first - << store.printStorePath(i.second.path); - if (i.second.hash) { - out << i.second.hash->printMethodAlgo() - << i.second.hash->hash.to_string(Base16, false); - } else { - out << "" << ""; - } + << store.printStorePath(i.second.second); + std::visit(overloaded { + [&](DerivationOutputInputAddressed doi) { + out << "" << ""; + }, + [&](DerivationOutputCAFixed dof) { + out << dof.hash.printMethodAlgo() + << dof.hash.hash.to_string(Base16, false); + }, + [&](DerivationOutputCAFloating dof) { + out << (makeFileIngestionPrefix(dof.method) + printHashType(dof.hashType)) + << ""; + }, + }, i.second.first.output); } writeStorePaths(store, out, drv.inputSrcs); out << drv.platform << drv.builder << drv.args; |