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-rw-r--r--nix/nix-daemon/nix-daemon.cc939
1 files changed, 939 insertions, 0 deletions
diff --git a/nix/nix-daemon/nix-daemon.cc b/nix/nix-daemon/nix-daemon.cc
new file mode 100644
index 0000000000..8814fe3155
--- /dev/null
+++ b/nix/nix-daemon/nix-daemon.cc
@@ -0,0 +1,939 @@
+#include "shared.hh"
+#include "local-store.hh"
+#include "util.hh"
+#include "serialise.hh"
+#include "worker-protocol.hh"
+#include "archive.hh"
+#include "affinity.hh"
+#include "globals.hh"
+
+#include <cstring>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <fcntl.h>
+#include <errno.h>
+
+using namespace nix;
+
+
+/* On platforms that have O_ASYNC, we can detect when a client
+ disconnects and immediately kill any ongoing builds. On platforms
+ that lack it, we only notice the disconnection the next time we try
+ to write to the client. So if you have a builder that never
+ generates output on stdout/stderr, the daemon will never notice
+ that the client has disconnected until the builder terminates.
+
+ GNU/Hurd does have O_ASYNC, but its Unix-domain socket translator
+ (pflocal) does not implement F_SETOWN. See
+ <http://lists.gnu.org/archive/html/bug-guix/2013-07/msg00021.html> for
+ details.*/
+#if defined O_ASYNC && !defined __GNU__
+#define HAVE_HUP_NOTIFICATION
+#ifndef SIGPOLL
+#define SIGPOLL SIGIO
+#endif
+#endif
+
+
+static FdSource from(STDIN_FILENO);
+static FdSink to(STDOUT_FILENO);
+
+bool canSendStderr;
+pid_t myPid;
+
+
+
+/* This function is called anytime we want to write something to
+ stderr. If we're in a state where the protocol allows it (i.e.,
+ when canSendStderr), send the message to the client over the
+ socket. */
+static void tunnelStderr(const unsigned char * buf, size_t count)
+{
+ /* Don't send the message to the client if we're a child of the
+ process handling the connection. Otherwise we could screw up
+ the protocol. It's up to the parent to redirect stderr and
+ send it to the client somehow (e.g., as in build.cc). */
+ if (canSendStderr && myPid == getpid()) {
+ try {
+ writeInt(STDERR_NEXT, to);
+ writeString(buf, count, to);
+ to.flush();
+ } catch (...) {
+ /* Write failed; that means that the other side is
+ gone. */
+ canSendStderr = false;
+ throw;
+ }
+ } else
+ writeFull(STDERR_FILENO, buf, count);
+}
+
+
+/* Return true if the remote side has closed its end of the
+ connection, false otherwise. Should not be called on any socket on
+ which we expect input! */
+static bool isFarSideClosed(int socket)
+{
+ struct timeval timeout;
+ timeout.tv_sec = timeout.tv_usec = 0;
+
+ fd_set fds;
+ FD_ZERO(&fds);
+ FD_SET(socket, &fds);
+
+ while (select(socket + 1, &fds, 0, 0, &timeout) == -1)
+ if (errno != EINTR) throw SysError("select()");
+
+ if (!FD_ISSET(socket, &fds)) return false;
+
+ /* Destructive read to determine whether the select() marked the
+ socket as readable because there is actual input or because
+ we've reached EOF (i.e., a read of size 0 is available). */
+ char c;
+ int rd;
+ if ((rd = read(socket, &c, 1)) > 0)
+ throw Error("EOF expected (protocol error?)");
+ else if (rd == -1 && errno != ECONNRESET)
+ throw SysError("expected connection reset or EOF");
+
+ return true;
+}
+
+
+/* A SIGPOLL signal is received when data is available on the client
+ communication socket, or when the client has closed its side of the
+ socket. This handler is enabled at precisely those moments in the
+ protocol when we're doing work and the client is supposed to be
+ quiet. Thus, if we get a SIGPOLL signal, it means that the client
+ has quit. So we should quit as well.
+
+ Too bad most operating systems don't support the POLL_HUP value for
+ si_code in siginfo_t. That would make most of the SIGPOLL
+ complexity unnecessary, i.e., we could just enable SIGPOLL all the
+ time and wouldn't have to worry about races. */
+static void sigPollHandler(int sigNo)
+{
+ using namespace std;
+ try {
+ /* Check that the far side actually closed. We're still
+ getting spurious signals every once in a while. I.e.,
+ there is no input available, but we get a signal with
+ POLL_IN set. Maybe it's delayed or something. */
+ if (isFarSideClosed(from.fd)) {
+ if (!blockInt) {
+ _isInterrupted = 1;
+ blockInt = 1;
+ canSendStderr = false;
+ const char * s = "SIGPOLL\n";
+ write(STDERR_FILENO, s, strlen(s));
+ }
+ } else {
+ const char * s = "spurious SIGPOLL\n";
+ write(STDERR_FILENO, s, strlen(s));
+ }
+ }
+ catch (Error & e) {
+ /* Shouldn't happen. */
+ string s = "impossible: " + e.msg() + '\n';
+ write(STDERR_FILENO, s.data(), s.size());
+ throw;
+ }
+}
+
+
+static void setSigPollAction(bool enable)
+{
+#ifdef HAVE_HUP_NOTIFICATION
+ struct sigaction act, oact;
+ act.sa_handler = enable ? sigPollHandler : SIG_IGN;
+ sigfillset(&act.sa_mask);
+ act.sa_flags = 0;
+ if (sigaction(SIGPOLL, &act, &oact))
+ throw SysError("setting handler for SIGPOLL");
+#endif
+}
+
+
+/* startWork() means that we're starting an operation for which we
+ want to send out stderr to the client. */
+static void startWork()
+{
+ canSendStderr = true;
+
+ /* Handle client death asynchronously. */
+ setSigPollAction(true);
+
+ /* Of course, there is a race condition here: the socket could
+ have closed between when we last read from / wrote to it, and
+ between the time we set the handler for SIGPOLL. In that case
+ we won't get the signal. So do a non-blocking select() to find
+ out if any input is available on the socket. If there is, it
+ has to be the 0-byte read that indicates that the socket has
+ closed. */
+ if (isFarSideClosed(from.fd)) {
+ _isInterrupted = 1;
+ checkInterrupt();
+ }
+}
+
+
+/* stopWork() means that we're done; stop sending stderr to the
+ client. */
+static void stopWork(bool success = true, const string & msg = "", unsigned int status = 0)
+{
+ /* Stop handling async client death; we're going to a state where
+ we're either sending or receiving from the client, so we'll be
+ notified of client death anyway. */
+ setSigPollAction(false);
+
+ canSendStderr = false;
+
+ if (success)
+ writeInt(STDERR_LAST, to);
+ else {
+ writeInt(STDERR_ERROR, to);
+ writeString(msg, to);
+ if (status != 0) writeInt(status, to);
+ }
+}
+
+
+struct TunnelSink : Sink
+{
+ Sink & to;
+ TunnelSink(Sink & to) : to(to) { }
+ virtual void operator () (const unsigned char * data, size_t len)
+ {
+ writeInt(STDERR_WRITE, to);
+ writeString(data, len, to);
+ }
+};
+
+
+struct TunnelSource : BufferedSource
+{
+ Source & from;
+ TunnelSource(Source & from) : from(from) { }
+ size_t readUnbuffered(unsigned char * data, size_t len)
+ {
+ /* Careful: we're going to receive data from the client now,
+ so we have to disable the SIGPOLL handler. */
+ setSigPollAction(false);
+ canSendStderr = false;
+
+ writeInt(STDERR_READ, to);
+ writeInt(len, to);
+ to.flush();
+ size_t n = readString(data, len, from);
+
+ startWork();
+ 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;
+ }
+};
+
+
+/* Adapter class of a Source that saves all data read to `s'. */
+struct SavingSourceAdapter : Source
+{
+ Source & orig;
+ string s;
+ SavingSourceAdapter(Source & orig) : orig(orig) { }
+ size_t read(unsigned char * data, size_t len)
+ {
+ size_t n = orig.read(data, len);
+ s.append((const char *) data, n);
+ return n;
+ }
+};
+
+
+static void performOp(bool trusted, unsigned int clientVersion,
+ Source & from, Sink & to, unsigned int op)
+{
+ switch (op) {
+
+#if 0
+ case wopQuit: {
+ /* Close the database. */
+ store.reset((StoreAPI *) 0);
+ writeInt(1, to);
+ break;
+ }
+#endif
+
+ case wopIsValidPath: {
+ /* 'readStorePath' could raise an error leading to the connection
+ being closed. To be able to recover from an invalid path error,
+ call 'startWork' early, and do 'assertStorePath' afterwards so
+ that the 'Error' exception handler doesn't close the
+ connection. */
+ Path path = readString(from);
+ startWork();
+ assertStorePath(path);
+ bool result = store->isValidPath(path);
+ stopWork();
+ writeInt(result, to);
+ break;
+ }
+
+ case wopQueryValidPaths: {
+ PathSet paths = readStorePaths<PathSet>(from);
+ startWork();
+ PathSet res = store->queryValidPaths(paths);
+ stopWork();
+ writeStrings(res, to);
+ break;
+ }
+
+ case wopHasSubstitutes: {
+ Path path = readStorePath(from);
+ startWork();
+ PathSet res = store->querySubstitutablePaths(singleton<PathSet>(path));
+ stopWork();
+ writeInt(res.find(path) != res.end(), to);
+ break;
+ }
+
+ case wopQuerySubstitutablePaths: {
+ PathSet paths = readStorePaths<PathSet>(from);
+ startWork();
+ PathSet res = store->querySubstitutablePaths(paths);
+ stopWork();
+ writeStrings(res, to);
+ break;
+ }
+
+ case wopQueryPathHash: {
+ Path path = readStorePath(from);
+ startWork();
+ Hash hash = store->queryPathHash(path);
+ stopWork();
+ writeString(printHash(hash), to);
+ break;
+ }
+
+ case wopQueryReferences:
+ case wopQueryReferrers:
+ case wopQueryValidDerivers:
+ case wopQueryDerivationOutputs: {
+ Path path = readStorePath(from);
+ startWork();
+ PathSet paths;
+ if (op == wopQueryReferences)
+ store->queryReferences(path, paths);
+ else if (op == wopQueryReferrers)
+ store->queryReferrers(path, paths);
+ else if (op == wopQueryValidDerivers)
+ paths = store->queryValidDerivers(path);
+ else paths = store->queryDerivationOutputs(path);
+ stopWork();
+ writeStrings(paths, to);
+ break;
+ }
+
+ case wopQueryDerivationOutputNames: {
+ Path path = readStorePath(from);
+ startWork();
+ StringSet names;
+ names = store->queryDerivationOutputNames(path);
+ stopWork();
+ writeStrings(names, to);
+ break;
+ }
+
+ case wopQueryDeriver: {
+ Path path = readStorePath(from);
+ startWork();
+ Path deriver = store->queryDeriver(path);
+ stopWork();
+ writeString(deriver, to);
+ break;
+ }
+
+ case wopQueryPathFromHashPart: {
+ string hashPart = readString(from);
+ startWork();
+ Path path = store->queryPathFromHashPart(hashPart);
+ stopWork();
+ writeString(path, to);
+ break;
+ }
+
+ case wopAddToStore: {
+ string baseName = readString(from);
+ bool fixed = readInt(from) == 1; /* obsolete */
+ bool recursive = readInt(from) == 1;
+ string s = readString(from);
+ /* Compatibility hack. */
+ if (!fixed) {
+ s = "sha256";
+ recursive = true;
+ }
+ HashType hashAlgo = parseHashType(s);
+
+ SavingSourceAdapter 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);
+
+ startWork();
+ if (!savedRegular.regular) throw Error("regular file expected");
+ Path path = dynamic_cast<LocalStore *>(store.get())
+ ->addToStoreFromDump(recursive ? savedNAR.s : savedRegular.s, baseName, recursive, hashAlgo);
+ stopWork();
+
+ writeString(path, to);
+ break;
+ }
+
+ case wopAddTextToStore: {
+ string suffix = readString(from);
+ string s = readString(from);
+ PathSet refs = readStorePaths<PathSet>(from);
+ startWork();
+ Path path = store->addTextToStore(suffix, s, refs);
+ stopWork();
+ writeString(path, to);
+ break;
+ }
+
+ case wopExportPath: {
+ Path path = readStorePath(from);
+ bool sign = readInt(from) == 1;
+ startWork();
+ TunnelSink sink(to);
+ store->exportPath(path, sign, sink);
+ stopWork();
+ writeInt(1, to);
+ break;
+ }
+
+ case wopImportPaths: {
+ startWork();
+ TunnelSource source(from);
+ Paths paths = store->importPaths(true, source);
+ stopWork();
+ writeStrings(paths, to);
+ break;
+ }
+
+ case wopBuildPaths: {
+ PathSet drvs = readStorePaths<PathSet>(from);
+ startWork();
+ store->buildPaths(drvs);
+ stopWork();
+ writeInt(1, to);
+ break;
+ }
+
+ case wopEnsurePath: {
+ Path path = readStorePath(from);
+ startWork();
+ store->ensurePath(path);
+ stopWork();
+ writeInt(1, to);
+ break;
+ }
+
+ case wopAddTempRoot: {
+ Path path = readStorePath(from);
+ startWork();
+ store->addTempRoot(path);
+ stopWork();
+ writeInt(1, to);
+ break;
+ }
+
+ case wopAddIndirectRoot: {
+ Path path = absPath(readString(from));
+ startWork();
+ store->addIndirectRoot(path);
+ stopWork();
+ writeInt(1, to);
+ break;
+ }
+
+ case wopSyncWithGC: {
+ startWork();
+ store->syncWithGC();
+ stopWork();
+ writeInt(1, to);
+ break;
+ }
+
+ case wopFindRoots: {
+ startWork();
+ Roots roots = store->findRoots();
+ stopWork();
+ writeInt(roots.size(), to);
+ for (Roots::iterator i = roots.begin(); i != roots.end(); ++i) {
+ writeString(i->first, to);
+ writeString(i->second, to);
+ }
+ break;
+ }
+
+ case wopCollectGarbage: {
+ GCOptions options;
+ options.action = (GCOptions::GCAction) readInt(from);
+ options.pathsToDelete = readStorePaths<PathSet>(from);
+ options.ignoreLiveness = readInt(from);
+ options.maxFreed = readLongLong(from);
+ readInt(from); // obsolete field
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 5) {
+ /* removed options */
+ readInt(from);
+ readInt(from);
+ }
+
+ GCResults results;
+
+ startWork();
+ if (options.ignoreLiveness)
+ throw Error("you are not allowed to ignore liveness");
+ store->collectGarbage(options, results);
+ stopWork();
+
+ writeStrings(results.paths, to);
+ writeLongLong(results.bytesFreed, to);
+ writeLongLong(0, to); // obsolete
+
+ break;
+ }
+
+ case wopSetOptions: {
+ settings.keepFailed = readInt(from) != 0;
+ settings.keepGoing = readInt(from) != 0;
+ settings.set("build-fallback", readInt(from) ? "true" : "false");
+ verbosity = (Verbosity) readInt(from);
+ settings.set("build-max-jobs", int2String(readInt(from)));
+ settings.set("build-max-silent-time", int2String(readInt(from)));
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 2)
+ settings.useBuildHook = readInt(from) != 0;
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 4) {
+ settings.buildVerbosity = (Verbosity) readInt(from);
+ logType = (LogType) readInt(from);
+ settings.printBuildTrace = readInt(from) != 0;
+ }
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 6)
+ settings.set("build-cores", int2String(readInt(from)));
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 10)
+ settings.set("build-use-substitutes", readInt(from) ? "true" : "false");
+ 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);
+ if (name == "build-timeout" || name == "use-ssh-substituter")
+ settings.set(name, value);
+ else
+ settings.set(trusted ? name : "untrusted-" + name, value);
+ }
+ }
+ settings.update();
+ startWork();
+ stopWork();
+ break;
+ }
+
+ case wopQuerySubstitutablePathInfo: {
+ Path path = absPath(readString(from));
+ startWork();
+ SubstitutablePathInfos infos;
+ store->querySubstitutablePathInfos(singleton<PathSet>(path), infos);
+ stopWork();
+ SubstitutablePathInfos::iterator i = infos.find(path);
+ if (i == infos.end())
+ writeInt(0, to);
+ else {
+ writeInt(1, to);
+ writeString(i->second.deriver, to);
+ writeStrings(i->second.references, to);
+ writeLongLong(i->second.downloadSize, to);
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 7)
+ writeLongLong(i->second.narSize, to);
+ }
+ break;
+ }
+
+ case wopQuerySubstitutablePathInfos: {
+ PathSet paths = readStorePaths<PathSet>(from);
+ startWork();
+ SubstitutablePathInfos infos;
+ store->querySubstitutablePathInfos(paths, infos);
+ stopWork();
+ writeInt(infos.size(), to);
+ foreach (SubstitutablePathInfos::iterator, i, infos) {
+ writeString(i->first, to);
+ writeString(i->second.deriver, to);
+ writeStrings(i->second.references, to);
+ writeLongLong(i->second.downloadSize, to);
+ writeLongLong(i->second.narSize, to);
+ }
+ break;
+ }
+
+ case wopQueryAllValidPaths: {
+ startWork();
+ PathSet paths = store->queryAllValidPaths();
+ stopWork();
+ writeStrings(paths, to);
+ break;
+ }
+
+ case wopQueryFailedPaths: {
+ startWork();
+ PathSet paths = store->queryFailedPaths();
+ stopWork();
+ writeStrings(paths, to);
+ break;
+ }
+
+ case wopClearFailedPaths: {
+ PathSet paths = readStrings<PathSet>(from);
+ startWork();
+ store->clearFailedPaths(paths);
+ stopWork();
+ writeInt(1, to);
+ break;
+ }
+
+ case wopQueryPathInfo: {
+ Path path = readStorePath(from);
+ startWork();
+ ValidPathInfo info = store->queryPathInfo(path);
+ stopWork();
+ writeString(info.deriver, to);
+ writeString(printHash(info.hash), to);
+ writeStrings(info.references, to);
+ writeInt(info.registrationTime, to);
+ writeLongLong(info.narSize, to);
+ break;
+ }
+
+ default:
+ throw Error(format("invalid operation %1%") % op);
+ }
+}
+
+
+static void processConnection(bool trusted)
+{
+ canSendStderr = false;
+ myPid = getpid();
+ _writeToStderr = tunnelStderr;
+
+#ifdef HAVE_HUP_NOTIFICATION
+ /* Allow us to receive SIGPOLL for events on the client socket. */
+ setSigPollAction(false);
+ if (fcntl(from.fd, F_SETOWN, getpid()) == -1)
+ throw SysError("F_SETOWN");
+ if (fcntl(from.fd, F_SETFL, fcntl(from.fd, F_GETFL, 0) | O_ASYNC) == -1)
+ throw SysError("F_SETFL");
+#endif
+
+ /* Exchange the greeting. */
+ unsigned int magic = readInt(from);
+ if (magic != WORKER_MAGIC_1) throw Error("protocol mismatch");
+ writeInt(WORKER_MAGIC_2, to);
+ writeInt(PROTOCOL_VERSION, to);
+ to.flush();
+ unsigned int clientVersion = readInt(from);
+
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 14 && readInt(from))
+ setAffinityTo(readInt(from));
+
+ bool reserveSpace = true;
+ if (GET_PROTOCOL_MINOR(clientVersion) >= 11)
+ reserveSpace = readInt(from) != 0;
+
+ /* Send startup error messages to the client. */
+ 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
+
+ /* Open the store. */
+ store = std::shared_ptr<StoreAPI>(new LocalStore(reserveSpace));
+
+ stopWork();
+ to.flush();
+
+ } catch (Error & e) {
+ stopWork(false, e.msg());
+ to.flush();
+ return;
+ }
+
+ /* Process client requests. */
+ unsigned int opCount = 0;
+
+ while (true) {
+ WorkerOp op;
+ try {
+ op = (WorkerOp) readInt(from);
+ } catch (EndOfFile & e) {
+ break;
+ }
+
+ opCount++;
+
+ try {
+ performOp(trusted, 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 = canSendStderr;
+ if (!errorAllowed) printMsg(lvlError, format("error processing client input: %1%") % e.msg());
+ stopWork(false, e.msg(), GET_PROTOCOL_MINOR(clientVersion) >= 8 ? e.status : 0);
+ if (!errorAllowed) break;
+ } catch (std::bad_alloc & e) {
+ if (canSendStderr)
+ stopWork(false, "Nix daemon out of memory", GET_PROTOCOL_MINOR(clientVersion) >= 8 ? 1 : 0);
+ throw;
+ }
+
+ to.flush();
+
+ assert(!canSendStderr);
+ };
+
+ printMsg(lvlError, format("%1% operations") % opCount);
+}
+
+
+static void sigChldHandler(int sigNo)
+{
+ /* Reap all dead children. */
+ while (waitpid(-1, 0, WNOHANG) > 0) ;
+}
+
+
+static void setSigChldAction(bool autoReap)
+{
+ struct sigaction act, oact;
+ act.sa_handler = autoReap ? sigChldHandler : SIG_DFL;
+ sigfillset(&act.sa_mask);
+ act.sa_flags = 0;
+ if (sigaction(SIGCHLD, &act, &oact))
+ throw SysError("setting SIGCHLD handler");
+}
+
+
+#define SD_LISTEN_FDS_START 3
+
+
+static void daemonLoop()
+{
+ /* Get rid of children automatically; don't let them become
+ zombies. */
+ setSigChldAction(true);
+
+ AutoCloseFD fdSocket;
+
+ /* Handle socket-based activation by systemd. */
+ if (getEnv("LISTEN_FDS") != "") {
+ if (getEnv("LISTEN_PID") != int2String(getpid()) || getEnv("LISTEN_FDS") != "1")
+ throw Error("unexpected systemd environment variables");
+ fdSocket = SD_LISTEN_FDS_START;
+ }
+
+ /* Otherwise, create and bind to a Unix domain socket. */
+ else {
+
+ /* Create and bind to a Unix domain socket. */
+ fdSocket = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (fdSocket == -1)
+ throw SysError("cannot create Unix domain socket");
+
+ string socketPath = settings.nixDaemonSocketFile;
+
+ createDirs(dirOf(socketPath));
+
+ /* Urgh, sockaddr_un allows path names of only 108 characters.
+ So chdir to the socket directory so that we can pass a
+ relative path name. */
+ chdir(dirOf(socketPath).c_str());
+ Path socketPathRel = "./" + baseNameOf(socketPath);
+
+ struct sockaddr_un addr;
+ addr.sun_family = AF_UNIX;
+ if (socketPathRel.size() >= sizeof(addr.sun_path))
+ throw Error(format("socket path `%1%' is too long") % socketPathRel);
+ strcpy(addr.sun_path, socketPathRel.c_str());
+
+ unlink(socketPath.c_str());
+
+ /* Make sure that the socket is created with 0666 permission
+ (everybody can connect --- provided they have access to the
+ directory containing the socket). */
+ mode_t oldMode = umask(0111);
+ int res = bind(fdSocket, (struct sockaddr *) &addr, sizeof(addr));
+ umask(oldMode);
+ if (res == -1)
+ throw SysError(format("cannot bind to socket `%1%'") % socketPath);
+
+ chdir("/"); /* back to the root */
+
+ if (listen(fdSocket, 5) == -1)
+ throw SysError(format("cannot listen on socket `%1%'") % socketPath);
+ }
+
+ closeOnExec(fdSocket);
+
+ /* Loop accepting connections. */
+ while (1) {
+
+ try {
+ /* Important: the server process *cannot* open the SQLite
+ database, because it doesn't like forks very much. */
+ assert(!store);
+
+ /* Accept a connection. */
+ struct sockaddr_un remoteAddr;
+ socklen_t remoteAddrLen = sizeof(remoteAddr);
+
+ AutoCloseFD remote = accept(fdSocket,
+ (struct sockaddr *) &remoteAddr, &remoteAddrLen);
+ checkInterrupt();
+ if (remote == -1) {
+ if (errno == EINTR)
+ continue;
+ else
+ throw SysError("accepting connection");
+ }
+
+ closeOnExec(remote);
+
+ /* Get the identity of the caller, if possible. */
+ uid_t clientUid = -1;
+ pid_t clientPid = -1;
+ bool trusted = false;
+
+#if defined(SO_PEERCRED)
+ ucred cred;
+ socklen_t credLen = sizeof(cred);
+ if (getsockopt(remote, SOL_SOCKET, SO_PEERCRED, &cred, &credLen) != -1) {
+ clientPid = cred.pid;
+ clientUid = cred.uid;
+ if (clientUid == 0) trusted = true;
+ }
+#endif
+
+ printMsg(lvlInfo, format("accepted connection from pid %1%, uid %2%") % clientPid % clientUid);
+
+ /* Fork a child to handle the connection. */
+ pid_t child;
+ child = fork();
+
+ switch (child) {
+
+ case -1:
+ throw SysError("unable to fork");
+
+ case 0:
+ try { /* child */
+
+ /* Background the daemon. */
+ if (setsid() == -1)
+ throw SysError(format("creating a new session"));
+
+ /* Restore normal handling of SIGCHLD. */
+ setSigChldAction(false);
+
+ /* For debugging, stuff the pid into argv[1]. */
+ if (clientPid != -1 && argvSaved[1]) {
+ string processName = int2String(clientPid);
+ strncpy(argvSaved[1], processName.c_str(), strlen(argvSaved[1]));
+ }
+
+ /* Handle the connection. */
+ from.fd = remote;
+ to.fd = remote;
+ processConnection(trusted);
+
+ } catch (std::exception & e) {
+ writeToStderr("unexpected Nix daemon error: " + string(e.what()) + "\n");
+ }
+ exit(0);
+ }
+
+ } catch (Interrupted & e) {
+ throw;
+ } catch (Error & e) {
+ printMsg(lvlError, format("error processing connection: %1%") % e.msg());
+ }
+ }
+}
+
+
+void run(Strings args)
+{
+ for (Strings::iterator i = args.begin(); i != args.end(); ) {
+ string arg = *i++;
+ if (arg == "--daemon") /* ignored for backwards compatibility */;
+ }
+
+ chdir("/");
+ daemonLoop();
+}
+
+
+void printHelp()
+{
+ showManPage("nix-daemon");
+}
+
+
+string programId = "nix-daemon";
generated by cgit v1.2.3 (git 2.45.0) at 2024-11-17 17:22:25 +0000