lix/src/libstore/daemon.cc
Eelco Dolstra bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00

845 lines
25 KiB
C++

#include "daemon.hh"
#include "monitor-fd.hh"
#include "worker-protocol.hh"
#include "store-api.hh"
#include "local-store.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);
}
/* 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(bool success = true, const string & msg = "", unsigned int status = 0)
{
auto state(state_.lock());
state->canSendStderr = false;
if (success)
to << STDERR_LAST;
else {
to << STDERR_ERROR << msg;
if (status != 0) to << 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;
}
};
/* If the NAR archive contains a single file at top-level, then save
the contents of the file to `s'. Otherwise barf. */
struct RetrieveRegularNARSink : ParseSink
{
bool regular;
string s;
RetrieveRegularNARSink() : regular(true) { }
void createDirectory(const Path & path)
{
regular = false;
}
void receiveContents(unsigned char * data, unsigned int len)
{
s.append((const char *) data, len);
}
void createSymlink(const Path & path, const string & target)
{
regular = false;
}
};
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
warn("ignoring the user-specified setting '%s', because it is a restricted setting and you are not a trusted user", name);
} catch (UsageError & e) {
warn(e.what());
}
}
}
};
static void performOp(TunnelLogger * logger, ref<Store> store,
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: {
auto paths = readStorePaths<StorePathSet>(*store, from);
logger->startWork();
auto res = store->queryValidPaths(paths);
logger->stopWork();
writeStorePaths(*store, to, res);
break;
}
case wopHasSubstitutes: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
StorePathSet paths; // FIXME
paths.insert(path.clone());
auto res = store->querySubstitutablePaths(paths);
logger->stopWork();
to << (res.count(path) != 0);
break;
}
case wopQuerySubstitutablePaths: {
auto paths = readStorePaths<StorePathSet>(*store, from);
logger->startWork();
auto res = store->querySubstitutablePaths(paths);
logger->stopWork();
writeStorePaths(*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)->references)
paths.insert(i.clone());
else if (op == wopQueryReferrers)
store->queryReferrers(path, paths);
else if (op == wopQueryValidDerivers)
paths = store->queryValidDerivers(path);
else paths = store->queryDerivationOutputs(path);
logger->stopWork();
writeStorePaths(*store, to, paths);
break;
}
case wopQueryDerivationOutputNames: {
auto path = store->parseStorePath(readString(from));
logger->startWork();
StringSet names;
names = store->queryDerivationOutputNames(path);
logger->stopWork();
to << names;
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: {
bool fixed, recursive;
std::string s, baseName;
from >> baseName >> fixed /* obsolete */ >> recursive >> s;
/* Compatibility hack. */
if (!fixed) {
s = "sha256";
recursive = true;
}
HashType hashAlgo = parseHashType(s);
TeeSource savedNAR(from);
RetrieveRegularNARSink savedRegular;
if (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, savedNAR);
} else
parseDump(savedRegular, from);
logger->startWork();
if (!savedRegular.regular) throw Error("regular file expected");
auto path = store->addToStoreFromDump(recursive ? *savedNAR.data : savedRegular.s, baseName, recursive, hashAlgo);
logger->stopWork();
to << store->printStorePath(path);
break;
}
case wopAddTextToStore: {
string suffix = readString(from);
string s = readString(from);
auto refs = readStorePaths<StorePathSet>(*store, from);
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, nullptr,
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->parseDrvPathWithOutputs(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);
BuildMode buildMode = (BuildMode) readInt(from);
logger->startWork();
if (!trusted)
throw Error("you are not privileged to build derivations");
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);
options.pathsToDelete = readStorePaths<StorePathSet>(*store, from);
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: {
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
clientSettings.verboseBuild = lvlError == (Verbosity) readInt(from);
readInt(from); // obsolete logType
readInt(from); // obsolete printBuildTrace
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);
clientSettings.overrides.emplace(name, value);
}
}
logger->startWork();
// 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;
StorePathSet paths;
paths.insert(path.clone()); // FIXME
store->querySubstitutablePathInfos(paths, 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) : "");
writeStorePaths(*store, to, i->second.references);
to << i->second.downloadSize
<< i->second.narSize;
}
break;
}
case wopQuerySubstitutablePathInfos: {
auto paths = readStorePaths<StorePathSet>(*store, from);
logger->startWork();
SubstitutablePathInfos infos;
store->querySubstitutablePathInfos(paths, infos);
logger->stopWork();
to << infos.size();
for (auto & i : infos) {
to << store->printStorePath(i.first)
<< (i.second.deriver ? store->printStorePath(*i.second.deriver) : "");
writeStorePaths(*store, to, i.second.references);
to << i.second.downloadSize << i.second.narSize;
}
break;
}
case wopQueryAllValidPaths: {
logger->startWork();
auto paths = store->queryAllValidPaths();
logger->stopWork();
writeStorePaths(*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;
to << (info->deriver ? store->printStorePath(*info->deriver) : "")
<< info->narHash.to_string(Base16, false);
writeStorePaths(*store, to, info->references);
to << info->registrationTime << info->narSize;
if (GET_PROTOCOL_MINOR(clientVersion) >= 16) {
to << info->ultimate
<< info->sigs
<< info->ca;
}
} 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();
dumpPath(store->printStorePath(path), to);
break;
}
case wopAddToStoreNar: {
bool repair, dontCheckSigs;
ValidPathInfo info(store->parseStorePath(readString(from)));
auto deriver = readString(from);
if (deriver != "")
info.deriver = store->parseStorePath(deriver);
info.narHash = Hash(readString(from), htSHA256);
info.references = readStorePaths<StorePathSet>(*store, from);
from >> info.registrationTime >> info.narSize >> info.ultimate;
info.sigs = readStrings<StringSet>(from);
from >> info.ca >> repair >> dontCheckSigs;
if (!trusted && dontCheckSigs)
dontCheckSigs = false;
if (!trusted)
info.ultimate = false;
std::string saved;
std::unique_ptr<Source> source;
if (GET_PROTOCOL_MINOR(clientVersion) >= 21)
source = std::make_unique<TunnelSource>(from, to);
else {
TeeSink tee(from);
parseDump(tee, tee.source);
saved = std::move(*tee.source.data);
source = std::make_unique<StringSource>(saved);
}
logger->startWork();
// FIXME: race if addToStore doesn't read source?
store->addToStore(info, *source, (RepairFlag) repair,
dontCheckSigs ? NoCheckSigs : CheckSigs, nullptr);
logger->stopWork();
break;
}
case wopQueryMissing: {
std::vector<StorePathWithOutputs> targets;
for (auto & s : readStrings<Strings>(from))
targets.push_back(store->parseDrvPathWithOutputs(s));
logger->startWork();
StorePathSet willBuild, willSubstitute, unknown;
unsigned long long downloadSize, narSize;
store->queryMissing(targets, willBuild, willSubstitute, unknown, downloadSize, narSize);
logger->stopWork();
writeStorePaths(*store, to, willBuild);
writeStorePaths(*store, to, willSubstitute);
writeStorePaths(*store, to, unknown);
to << downloadSize << narSize;
break;
}
default:
throw Error(format("invalid operation %1%") % op);
}
}
void processConnection(
ref<Store> store,
FdSource & from,
FdSink & to,
TrustedFlag trusted,
RecursiveFlag recursive,
const std::string & userName,
uid_t userId)
{
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;
// FIXME
if (!recursive)
logger = tunnelLogger;
unsigned int opCount = 0;
Finally finally([&]() {
_isInterrupted = false;
prevLogger->log(lvlDebug, fmt("%d operations", opCount));
});
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). */
#if 0
/* Prevent users from doing something very dangerous. */
if (geteuid() == 0 &&
querySetting("build-users-group", "") == "")
throw Error("if you run 'nix-daemon' as root, then you MUST set 'build-users-group'!");
#endif
store->createUser(userName, userId);
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 {
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(false, e.msg(), e.status);
if (!errorAllowed) throw;
} catch (std::bad_alloc & e) {
tunnelLogger->stopWork(false, "Nix daemon out of memory", 1);
throw;
}
to.flush();
assert(!tunnelLogger->state_.lock()->canSendStderr);
};
} catch (std::exception & e) {
tunnelLogger->stopWork(false, e.what(), 1);
to.flush();
return;
}
}
}