lix/src/libstore/daemon.cc

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#include "daemon.hh"
#include "monitor-fd.hh"
#include "worker-protocol.hh"
#include "store-api.hh"
#include "finally.hh"
#include "affinity.hh"
#include "archive.hh"
#include "derivations.hh"
#include "args.hh"
namespace nix::daemon {
Sink & operator << (Sink & sink, const Logger::Fields & fields)
{
sink << fields.size();
for (auto & f : fields) {
sink << f.type;
if (f.type == Logger::Field::tInt)
sink << f.i;
else if (f.type == Logger::Field::tString)
sink << f.s;
else abort();
}
return sink;
}
/* Logger that forwards log messages to the client, *if* we're in a
state where the protocol allows it (i.e., when canSendStderr is
true). */
struct TunnelLogger : public Logger
{
FdSink & to;
struct State
{
bool canSendStderr = false;
std::vector<std::string> pendingMsgs;
};
Sync<State> state_;
unsigned int clientVersion;
TunnelLogger(FdSink & to, unsigned int clientVersion)
: to(to), clientVersion(clientVersion) { }
void enqueueMsg(const std::string & s)
{
auto state(state_.lock());
if (state->canSendStderr) {
assert(state->pendingMsgs.empty());
try {
to(s);
to.flush();
} catch (...) {
/* Write failed; that means that the other side is
gone. */
state->canSendStderr = false;
throw;
}
} else
state->pendingMsgs.push_back(s);
}
void log(Verbosity lvl, const FormatOrString & fs) override
{
if (lvl > verbosity) return;
StringSink buf;
buf << STDERR_NEXT << (fs.s + "\n");
enqueueMsg(*buf.s);
}
void logEI(const ErrorInfo & ei) override
{
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if (ei.level > verbosity) return;
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std::stringstream oss;
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showErrorInfo(oss, ei, false);
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StringSink buf;
buf << STDERR_NEXT << oss.str();
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enqueueMsg(*buf.s);
}
/* startWork() means that we're starting an operation for which we
want to send out stderr to the client. */
void startWork()
{
auto state(state_.lock());
state->canSendStderr = true;
for (auto & msg : state->pendingMsgs)
to(msg);
state->pendingMsgs.clear();
to.flush();
}
/* stopWork() means that we're done; stop sending stderr to the
client. */
void stopWork(const Error * ex = nullptr)
{
auto state(state_.lock());
state->canSendStderr = false;
if (!ex)
to << STDERR_LAST;
else {
if (GET_PROTOCOL_MINOR(clientVersion) >= 26) {
to << STDERR_ERROR << *ex;
} else {
to << STDERR_ERROR << ex->what() << ex->status;
}
}
}
void startActivity(ActivityId act, Verbosity lvl, ActivityType type,
const std::string & s, const Fields & fields, ActivityId parent) override
{
if (GET_PROTOCOL_MINOR(clientVersion) < 20) {
if (!s.empty())
log(lvl, s + "...");
return;
}
StringSink buf;
buf << STDERR_START_ACTIVITY << act << lvl << type << s << fields << parent;
enqueueMsg(*buf.s);
}
void stopActivity(ActivityId act) override
{
if (GET_PROTOCOL_MINOR(clientVersion) < 20) return;
StringSink buf;
buf << STDERR_STOP_ACTIVITY << act;
enqueueMsg(*buf.s);
}
void result(ActivityId act, ResultType type, const Fields & fields) override
{
if (GET_PROTOCOL_MINOR(clientVersion) < 20) return;
StringSink buf;
buf << STDERR_RESULT << act << type << fields;
enqueueMsg(*buf.s);
}
};
struct TunnelSink : Sink
{
Sink & to;
TunnelSink(Sink & to) : to(to) { }
virtual void operator () (const unsigned char * data, size_t len)
{
to << STDERR_WRITE;
writeString(data, len, to);
}
};
struct TunnelSource : BufferedSource
{
Source & from;
BufferedSink & to;
TunnelSource(Source & from, BufferedSink & to) : from(from), to(to) { }
size_t readUnbuffered(unsigned char * data, size_t len) override
{
to << STDERR_READ << len;
to.flush();
size_t n = readString(data, len, from);
if (n == 0) throw EndOfFile("unexpected end-of-file");
return n;
}
};
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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struct ClientSettings
{
bool keepFailed;
bool keepGoing;
bool tryFallback;
Verbosity verbosity;
unsigned int maxBuildJobs;
time_t maxSilentTime;
bool verboseBuild;
unsigned int buildCores;
bool useSubstitutes;
StringMap overrides;
void apply(TrustedFlag trusted)
{
settings.keepFailed = keepFailed;
settings.keepGoing = keepGoing;
settings.tryFallback = tryFallback;
nix::verbosity = verbosity;
settings.maxBuildJobs.assign(maxBuildJobs);
settings.maxSilentTime = maxSilentTime;
settings.verboseBuild = verboseBuild;
settings.buildCores = buildCores;
settings.useSubstitutes = useSubstitutes;
for (auto & i : overrides) {
auto & name(i.first);
auto & value(i.second);
auto setSubstituters = [&](Setting<Strings> & res) {
if (name != res.name && res.aliases.count(name) == 0)
return false;
StringSet trusted = settings.trustedSubstituters;
for (auto & s : settings.substituters.get())
trusted.insert(s);
Strings subs;
auto ss = tokenizeString<Strings>(value);
for (auto & s : ss)
if (trusted.count(s))
subs.push_back(s);
else
warn("ignoring untrusted substituter '%s'", s);
res = subs;
return true;
};
try {
if (name == "ssh-auth-sock") // obsolete
;
else if (trusted
|| name == settings.buildTimeout.name
|| name == "connect-timeout"
|| (name == "builders" && value == ""))
settings.set(name, value);
else if (setSubstituters(settings.substituters))
;
else if (setSubstituters(settings.extraSubstituters))
;
else
debug("ignoring the client-specified setting '%s', because it is a restricted setting and you are not a trusted user", name);
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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} catch (UsageError & e) {
warn(e.what());
}
}
}
};
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static void writeValidPathInfo(
ref<Store> store,
unsigned int clientVersion,
Sink & to,
std::shared_ptr<const ValidPathInfo> info)
{
to << (info->deriver ? store->printStorePath(*info->deriver) : "")
<< info->narHash.to_string(Base16, false);
worker_proto::write(*store, to, info->referencesPossiblyToSelf());
to << info->registrationTime << info->narSize;
if (GET_PROTOCOL_MINOR(clientVersion) >= 16) {
to << info->ultimate
<< info->sigs
<< renderContentAddress(info->ca);
}
}
static void performOp(TunnelLogger * logger, ref<Store> store,
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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TrustedFlag trusted, RecursiveFlag recursive, unsigned int clientVersion,
Source & from, BufferedSink & to, unsigned int op)
{
switch (op) {
case wopIsValidPath: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
bool result = store->isValidPath(path);
logger->stopWork();
to << result;
break;
}
case wopQueryValidPaths: {
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auto paths = worker_proto::read(*store, from, Phantom<StorePathSet> {});
logger->startWork();
auto res = store->queryValidPaths(paths);
logger->stopWork();
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worker_proto::write(*store, to, res);
break;
}
case wopHasSubstitutes: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
StorePathSet paths; // FIXME
paths.insert(path);
auto res = store->querySubstitutablePaths(paths);
logger->stopWork();
to << (res.count(path) != 0);
break;
}
case wopQuerySubstitutablePaths: {
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auto paths = worker_proto::read(*store, from, Phantom<StorePathSet> {});
logger->startWork();
auto res = store->querySubstitutablePaths(paths);
logger->stopWork();
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worker_proto::write(*store, to, res);
break;
}
case wopQueryPathHash: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
auto hash = store->queryPathInfo(path)->narHash;
logger->stopWork();
to << hash.to_string(Base16, false);
break;
}
case wopQueryReferences:
case wopQueryReferrers:
case wopQueryValidDerivers:
case wopQueryDerivationOutputs: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
StorePathSet paths;
if (op == wopQueryReferences)
for (auto & i : store->queryPathInfo(path)->referencesPossiblyToSelf())
paths.insert(i);
else if (op == wopQueryReferrers)
store->queryReferrers(path, paths);
else if (op == wopQueryValidDerivers)
paths = store->queryValidDerivers(path);
else paths = store->queryDerivationOutputs(path);
logger->stopWork();
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worker_proto::write(*store, to, paths);
break;
}
case wopQueryDerivationOutputNames: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
auto names = store->readDerivation(path).outputNames();
logger->stopWork();
to << names;
break;
}
case wopQueryDerivationOutputMap: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
auto outputs = store->queryPartialDerivationOutputMap(path);
logger->stopWork();
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worker_proto::write(*store, to, outputs);
break;
}
case wopQueryDeriver: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
auto info = store->queryPathInfo(path);
logger->stopWork();
to << (info->deriver ? store->printStorePath(*info->deriver) : "");
break;
}
case wopQueryPathFromHashPart: {
auto hashPart = readString(from);
logger->startWork();
auto path = store->queryPathFromHashPart(hashPart);
logger->stopWork();
to << (path ? store->printStorePath(*path) : "");
break;
}
case wopAddToStore: {
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if (GET_PROTOCOL_MINOR(clientVersion) >= 25) {
auto name = readString(from);
auto camStr = readString(from);
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auto refs = worker_proto::read(*store, from, Phantom<StorePathSet> {});
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bool repairBool;
from >> repairBool;
auto repair = RepairFlag{repairBool};
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logger->startWork();
auto pathInfo = [&]() {
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// NB: FramedSource must be out of scope before logger->stopWork();
auto [contentAddressMethod, hashType] = parseContentAddressMethod(camStr);
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FramedSource source(from);
// TODO this is essentially RemoteStore::addCAToStore. Move it up to Store.
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return std::visit(overloaded {
[&](TextHashMethod _) {
if (hashType != htSHA256)
throw UnimplementedError("Only SHA-256 is supported for adding text-hashed data, but '%1' was given",
printHashType(hashType));
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// We could stream this by changing Store
std::string contents = source.drain();
auto path = store->addTextToStore(name, contents, refs, repair);
return store->queryPathInfo(path);
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},
[&](FileIngestionMethod fim) {
if (!refs.empty())
throw UnimplementedError("cannot yet have refs with flat or nar-hashed data");
auto path = store->addToStoreFromDump(source, name, fim, hashType, repair);
return store->queryPathInfo(path);
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},
}, contentAddressMethod);
}();
logger->stopWork();
to << store->printStorePath(pathInfo->path);
writeValidPathInfo(store, clientVersion, to, pathInfo);
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} else {
HashType hashAlgo;
std::string baseName;
FileIngestionMethod method;
{
bool fixed;
uint8_t recursive;
std::string hashAlgoRaw;
from >> baseName >> fixed /* obsolete */ >> recursive >> hashAlgoRaw;
if (recursive > (uint8_t) FileIngestionMethod::Recursive)
throw Error("unsupported FileIngestionMethod with value of %i; you may need to upgrade nix-daemon", recursive);
method = FileIngestionMethod { recursive };
/* Compatibility hack. */
if (!fixed) {
hashAlgoRaw = "sha256";
method = FileIngestionMethod::Recursive;
}
hashAlgo = parseHashType(hashAlgoRaw);
}
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StringSink saved;
TeeSource savedNARSource(from, saved);
RetrieveRegularNARSink savedRegular { saved };
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if (method == FileIngestionMethod::Recursive) {
/* Get the entire NAR dump from the client and save it to
a string so that we can pass it to
addToStoreFromDump(). */
ParseSink sink; /* null sink; just parse the NAR */
parseDump(sink, savedNARSource);
} else
parseDump(savedRegular, from);
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logger->startWork();
if (!savedRegular.regular) throw Error("regular file expected");
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// FIXME: try to stream directly from `from`.
StringSource dumpSource { *saved.s };
auto path = store->addToStoreFromDump(dumpSource, baseName, method, hashAlgo);
logger->stopWork();
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to << store->printStorePath(path);
}
break;
}
case wopAddTextToStore: {
string suffix = readString(from);
string s = readString(from);
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auto refs = worker_proto::read(*store, from, Phantom<StorePathSet> {});
logger->startWork();
auto path = store->addTextToStore(suffix, s, refs, NoRepair);
logger->stopWork();
to << store->printStorePath(path);
break;
}
case wopExportPath: {
auto path = store->parseStorePath(readString(from));
readInt(from); // obsolete
logger->startWork();
TunnelSink sink(to);
store->exportPath(path, sink);
logger->stopWork();
to << 1;
break;
}
case wopImportPaths: {
logger->startWork();
TunnelSource source(from, to);
auto paths = store->importPaths(source,
trusted ? NoCheckSigs : CheckSigs);
logger->stopWork();
Strings paths2;
for (auto & i : paths) paths2.push_back(store->printStorePath(i));
to << paths2;
break;
}
case wopBuildPaths: {
std::vector<StorePathWithOutputs> drvs;
for (auto & s : readStrings<Strings>(from))
drvs.push_back(store->parsePathWithOutputs(s));
BuildMode mode = bmNormal;
if (GET_PROTOCOL_MINOR(clientVersion) >= 15) {
mode = (BuildMode) readInt(from);
/* Repairing is not atomic, so disallowed for "untrusted"
clients. */
if (mode == bmRepair && !trusted)
throw Error("repairing is not allowed because you are not in 'trusted-users'");
}
logger->startWork();
store->buildPaths(drvs, mode);
logger->stopWork();
to << 1;
break;
}
case wopBuildDerivation: {
auto drvPath = store->parseStorePath(readString(from));
BasicDerivation drv;
readDerivation(from, *store, drv, Derivation::nameFromPath(drvPath));
BuildMode buildMode = (BuildMode) readInt(from);
logger->startWork();
/* Content-addressed derivations are trustless because their output paths
are verified by their content alone, so any derivation is free to
try to produce such a path.
Input-addressed derivation output paths, however, are calculated
from the derivation closure that produced them---even knowing the
root derivation is not enough. That the output data actually came
from those derivations is fundamentally unverifiable, but the daemon
trusts itself on that matter. The question instead is whether the
submitted plan has rights to the output paths it wants to fill, and
at least the derivation closure proves that.
It would have been nice if input-address algorithm merely depended
on the build time closure, rather than depending on the derivation
closure. That would mean input-addressed paths used at build time
would just be trusted and not need their own evidence. This is in
fact fine as the same guarantees would hold *inductively*: either
the remote builder has those paths and already trusts them, or it
needs to build them too and thus their evidence must be provided in
turn. The advantage of this variant algorithm is that the evidence
for input-addressed paths which the remote builder already has
doesn't need to be sent again.
That said, now that we have floating CA derivations, it is better
that people just migrate to those which also solve this problem, and
others. It's the same migration difficulty with strictly more
benefit.
Lastly, do note that when we parse fixed-output content-addressed
derivations, we throw out the precomputed output paths and just
store the hashes, so there aren't two competing sources of truth an
attacker could exploit. */
if (drv.type() == DerivationType::InputAddressed && !trusted)
throw Error("you are not privileged to build input-addressed derivations");
/* Make sure that the non-input-addressed derivations that got this far
are in fact content-addressed if we don't trust them. */
assert(derivationIsCA(drv.type()) || trusted);
/* Recompute the derivation path when we cannot trust the original. */
if (!trusted) {
/* Recomputing the derivation path for input-address derivations
makes it harder to audit them after the fact, since we need the
original not-necessarily-resolved derivation to verify the drv
derivation as adequate claim to the input-addressed output
paths. */
assert(derivationIsCA(drv.type()));
Derivation drv2;
static_cast<BasicDerivation &>(drv2) = drv;
drvPath = writeDerivation(*store, Derivation { drv2 });
}
auto res = store->buildDerivation(drvPath, drv, buildMode);
logger->stopWork();
to << res.status << res.errorMsg;
break;
}
case wopEnsurePath: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
store->ensurePath(path);
logger->stopWork();
to << 1;
break;
}
case wopAddTempRoot: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
store->addTempRoot(path);
logger->stopWork();
to << 1;
break;
}
case wopAddIndirectRoot: {
Path path = absPath(readString(from));
logger->startWork();
store->addIndirectRoot(path);
logger->stopWork();
to << 1;
break;
}
case wopSyncWithGC: {
logger->startWork();
store->syncWithGC();
logger->stopWork();
to << 1;
break;
}
case wopFindRoots: {
logger->startWork();
Roots roots = store->findRoots(!trusted);
logger->stopWork();
size_t size = 0;
for (auto & i : roots)
size += i.second.size();
to << size;
for (auto & [target, links] : roots)
for (auto & link : links)
to << link << store->printStorePath(target);
break;
}
case wopCollectGarbage: {
GCOptions options;
options.action = (GCOptions::GCAction) readInt(from);
2020-09-30 00:41:18 +00:00
options.pathsToDelete = worker_proto::read(*store, from, Phantom<StorePathSet> {});
from >> options.ignoreLiveness >> options.maxFreed;
// obsolete fields
readInt(from);
readInt(from);
readInt(from);
GCResults results;
logger->startWork();
if (options.ignoreLiveness)
throw Error("you are not allowed to ignore liveness");
store->collectGarbage(options, results);
logger->stopWork();
to << results.paths << results.bytesFreed << 0 /* obsolete */;
break;
}
case wopSetOptions: {
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
2018-10-02 14:01:26 +00:00
ClientSettings clientSettings;
clientSettings.keepFailed = readInt(from);
clientSettings.keepGoing = readInt(from);
clientSettings.tryFallback = readInt(from);
clientSettings.verbosity = (Verbosity) readInt(from);
clientSettings.maxBuildJobs = readInt(from);
clientSettings.maxSilentTime = readInt(from);
readInt(from); // obsolete useBuildHook
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
2018-10-02 14:01:26 +00:00
clientSettings.verboseBuild = lvlError == (Verbosity) readInt(from);
readInt(from); // obsolete logType
readInt(from); // obsolete printBuildTrace
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
2018-10-02 14:01:26 +00:00
clientSettings.buildCores = readInt(from);
clientSettings.useSubstitutes = readInt(from);
if (GET_PROTOCOL_MINOR(clientVersion) >= 12) {
unsigned int n = readInt(from);
for (unsigned int i = 0; i < n; i++) {
string name = readString(from);
string value = readString(from);
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
2018-10-02 14:01:26 +00:00
clientSettings.overrides.emplace(name, value);
}
}
logger->startWork();
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
2018-10-02 14:01:26 +00:00
// FIXME: use some setting in recursive mode. Will need to use
// non-global variables.
if (!recursive)
clientSettings.apply(trusted);
logger->stopWork();
break;
}
case wopQuerySubstitutablePathInfo: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
SubstitutablePathInfos infos;
store->querySubstitutablePathInfos({{path, std::nullopt}}, infos);
logger->stopWork();
auto i = infos.find(path);
if (i == infos.end())
to << 0;
else {
to << 1
<< (i->second.deriver ? store->printStorePath(*i->second.deriver) : "");
worker_proto::write(*store, to, i->second.referencesPossiblyToSelf(path));
to << i->second.downloadSize
<< i->second.narSize;
}
break;
}
case wopQuerySubstitutablePathInfos: {
SubstitutablePathInfos infos;
StorePathCAMap pathsMap = {};
if (GET_PROTOCOL_MINOR(clientVersion) < 22) {
2020-09-30 00:41:18 +00:00
auto paths = worker_proto::read(*store, from, Phantom<StorePathSet> {});
for (auto & path : paths)
pathsMap.emplace(path, std::nullopt);
} else
2020-09-30 00:41:18 +00:00
pathsMap = worker_proto::read(*store, from, Phantom<StorePathCAMap> {});
logger->startWork();
store->querySubstitutablePathInfos(pathsMap, infos);
logger->stopWork();
to << infos.size();
for (auto & i : infos) {
to << store->printStorePath(i.first)
<< (i.second.deriver ? store->printStorePath(*i.second.deriver) : "");
worker_proto::write(*store, to, i.second.referencesPossiblyToSelf(i.first));
to << i.second.downloadSize << i.second.narSize;
}
break;
}
case wopQueryAllValidPaths: {
logger->startWork();
auto paths = store->queryAllValidPaths();
logger->stopWork();
2020-09-30 00:41:18 +00:00
worker_proto::write(*store, to, paths);
break;
}
case wopQueryPathInfo: {
auto path = store->parseStorePath(readString(from));
std::shared_ptr<const ValidPathInfo> info;
logger->startWork();
try {
info = store->queryPathInfo(path);
} catch (InvalidPath &) {
if (GET_PROTOCOL_MINOR(clientVersion) < 17) throw;
}
logger->stopWork();
if (info) {
if (GET_PROTOCOL_MINOR(clientVersion) >= 17)
to << 1;
writeValidPathInfo(store, clientVersion, to, info);
} else {
assert(GET_PROTOCOL_MINOR(clientVersion) >= 17);
to << 0;
}
break;
}
case wopOptimiseStore:
logger->startWork();
store->optimiseStore();
logger->stopWork();
to << 1;
break;
case wopVerifyStore: {
bool checkContents, repair;
from >> checkContents >> repair;
logger->startWork();
if (repair && !trusted)
throw Error("you are not privileged to repair paths");
bool errors = store->verifyStore(checkContents, (RepairFlag) repair);
logger->stopWork();
to << errors;
break;
}
case wopAddSignatures: {
auto path = store->parseStorePath(readString(from));
StringSet sigs = readStrings<StringSet>(from);
logger->startWork();
if (!trusted)
throw Error("you are not privileged to add signatures");
store->addSignatures(path, sigs);
logger->stopWork();
to << 1;
break;
}
case wopNarFromPath: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
logger->stopWork();
2020-08-14 21:59:31 +00:00
dumpPath(store->toRealPath(path), to);
break;
}
case wopAddToStoreNar: {
bool repair, dontCheckSigs;
2020-08-06 18:31:48 +00:00
auto path = store->parseStorePath(readString(from));
auto deriver = readString(from);
2020-08-06 18:31:48 +00:00
auto narHash = Hash::parseAny(readString(from), htSHA256);
ValidPathInfo info { path, narHash };
if (deriver != "")
info.deriver = store->parseStorePath(deriver);
info.setReferencesPossiblyToSelf(worker_proto::read(*store, from, Phantom<StorePathSet> {}));
from >> info.registrationTime >> info.narSize >> info.ultimate;
info.sigs = readStrings<StringSet>(from);
info.ca = parseContentAddressOpt(readString(from));
2020-06-02 00:37:43 +00:00
from >> repair >> dontCheckSigs;
if (!trusted && dontCheckSigs)
dontCheckSigs = false;
if (!trusted)
info.ultimate = false;
if (GET_PROTOCOL_MINOR(clientVersion) >= 23) {
logger->startWork();
{
FramedSource source(from);
store->addToStore(info, source, (RepairFlag) repair,
dontCheckSigs ? NoCheckSigs : CheckSigs);
}
logger->stopWork();
}
else {
std::unique_ptr<Source> source;
if (GET_PROTOCOL_MINOR(clientVersion) >= 21)
source = std::make_unique<TunnelSource>(from, to);
else {
StringSink saved;
TeeSource tee { from, saved };
ParseSink ether;
parseDump(ether, tee);
source = std::make_unique<StringSource>(std::move(*saved.s));
}
logger->startWork();
// FIXME: race if addToStore doesn't read source?
store->addToStore(info, *source, (RepairFlag) repair,
dontCheckSigs ? NoCheckSigs : CheckSigs);
logger->stopWork();
}
break;
}
case wopQueryMissing: {
std::vector<StorePathWithOutputs> targets;
for (auto & s : readStrings<Strings>(from))
targets.push_back(store->parsePathWithOutputs(s));
logger->startWork();
StorePathSet willBuild, willSubstitute, unknown;
2020-07-30 11:10:49 +00:00
uint64_t downloadSize, narSize;
store->queryMissing(targets, willBuild, willSubstitute, unknown, downloadSize, narSize);
logger->stopWork();
2020-09-30 00:41:18 +00:00
worker_proto::write(*store, to, willBuild);
worker_proto::write(*store, to, willSubstitute);
worker_proto::write(*store, to, unknown);
to << downloadSize << narSize;
break;
}
default:
throw Error("invalid operation %1%", op);
}
}
void processConnection(
ref<Store> store,
FdSource & from,
FdSink & to,
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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TrustedFlag trusted,
RecursiveFlag recursive,
std::function<void(Store &)> authHook)
{
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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auto monitor = !recursive ? std::make_unique<MonitorFdHup>(from.fd) : nullptr;
/* Exchange the greeting. */
unsigned int magic = readInt(from);
if (magic != WORKER_MAGIC_1) throw Error("protocol mismatch");
to << WORKER_MAGIC_2 << PROTOCOL_VERSION;
to.flush();
unsigned int clientVersion = readInt(from);
if (clientVersion < 0x10a)
throw Error("the Nix client version is too old");
auto tunnelLogger = new TunnelLogger(to, clientVersion);
auto prevLogger = nix::logger;
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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// FIXME
if (!recursive)
logger = tunnelLogger;
unsigned int opCount = 0;
Finally finally([&]() {
_isInterrupted = false;
prevLogger->log(lvlDebug, fmt("%d operations", opCount));
});
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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if (GET_PROTOCOL_MINOR(clientVersion) >= 14 && readInt(from)) {
auto affinity = readInt(from);
setAffinityTo(affinity);
}
readInt(from); // obsolete reserveSpace
/* Send startup error messages to the client. */
tunnelLogger->startWork();
try {
/* If we can't accept clientVersion, then throw an error
*here* (not above). */
authHook(*store);
tunnelLogger->stopWork();
to.flush();
/* Process client requests. */
while (true) {
WorkerOp op;
try {
op = (WorkerOp) readInt(from);
} catch (Interrupted & e) {
break;
} catch (EndOfFile & e) {
break;
}
opCount++;
try {
Recursive Nix support This allows Nix builders to call Nix to build derivations, with some limitations. Example: let nixpkgs = fetchTarball channel:nixos-18.03; in with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ nix jq ]; NIX_PATH = "nixpkgs=${nixpkgs}"; } '' hello=$(nix-build -E '(import <nixpkgs> {}).hello.overrideDerivation (args: { name = "hello-3.5"; })') $hello/bin/hello mkdir -p $out/bin ln -s $hello/bin/hello $out/bin/hello nix path-info -r --json $hello | jq . '' This derivation makes a recursive Nix call to build GNU Hello and symlinks it from its $out, i.e. # ll ./result/bin/ lrwxrwxrwx 1 root root 63 Jan 1 1970 hello -> /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5/bin/hello # nix-store -qR ./result /nix/store/hwwqshlmazzjzj7yhrkyjydxamvvkfd3-glibc-2.26-131 /nix/store/s0awxrs71gickhaqdwxl506hzccb30y5-hello-3.5 /nix/store/sgmvvyw8vhfqdqb619bxkcpfn9lvd8ss-foo This is implemented as follows: * Before running the outer builder, Nix creates a Unix domain socket '.nix-socket' in the builder's temporary directory and sets $NIX_REMOTE to point to it. It starts a thread to process connections to this socket. (Thus you don't need to have nix-daemon running.) * The daemon thread uses a wrapper store (RestrictedStore) to keep track of paths added through recursive Nix calls, to implement some restrictions (see below), and to do some censorship (e.g. for purity, queryPathInfo() won't return impure information such as signatures and timestamps). * After the build finishes, the output paths are scanned for references to the paths added through recursive Nix calls (in addition to the inputs closure). Thus, in the example above, $out has a reference to $hello. The main restriction on recursive Nix calls is that they cannot do arbitrary substitutions. For example, doing nix-store -r /nix/store/kmwd1hq55akdb9sc7l3finr175dajlby-hello-2.10 is forbidden unless /nix/store/kmwd... is in the inputs closure or previously built by a recursive Nix call. This is to prevent irreproducible derivations that have hidden dependencies on substituters or the current store contents. Building a derivation is fine, however, and Nix will use substitutes if available. In other words, the builder has to present proof that it knows how to build a desired store path from scratch by constructing a derivation graph for that path. Probably we should also disallow instantiating/building fixed-output derivations (specifically, those that access the network, but currently we have no way to mark fixed-output derivations that don't access the network). Otherwise sandboxed derivations can bypass sandbox restrictions and access the network. When sandboxing is enabled, we make paths appear in the sandbox of the builder by entering the mount namespace of the builder and bind-mounting each path. This is tricky because we do a pivot_root() in the builder to change the root directory of its mount namespace, and thus the host /nix/store is not visible in the mount namespace of the builder. To get around this, just before doing pivot_root(), we branch a second mount namespace that shares its /nix/store mountpoint with the parent. Recursive Nix currently doesn't work on macOS in sandboxed mode (because we can't change the sandbox policy of a running build) and in non-root mode (because setns() barfs).
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performOp(tunnelLogger, store, trusted, recursive, clientVersion, from, to, op);
} catch (Error & e) {
/* If we're not in a state where we can send replies, then
something went wrong processing the input of the
client. This can happen especially if I/O errors occur
during addTextToStore() / importPath(). If that
happens, just send the error message and exit. */
bool errorAllowed = tunnelLogger->state_.lock()->canSendStderr;
tunnelLogger->stopWork(&e);
if (!errorAllowed) throw;
} catch (std::bad_alloc & e) {
auto ex = Error("Nix daemon out of memory");
tunnelLogger->stopWork(&ex);
throw;
}
to.flush();
assert(!tunnelLogger->state_.lock()->canSendStderr);
};
} catch (Error & e) {
tunnelLogger->stopWork(&e);
to.flush();
return;
} catch (std::exception & e) {
auto ex = Error(e.what());
tunnelLogger->stopWork(&ex);
to.flush();
return;
}
}
}