* Rename all those main.cc files.
This commit is contained in:
Eelco Dolstra
parent
d03f0d4117
commit
4ca01065c3
10 changed files with 5 additions and 5 deletions
569
src/nix-worker/nix-worker.cc
Normal file
569
src/nix-worker/nix-worker.cc
Normal file
|
|
@ -0,0 +1,569 @@
|
|||
#include "shared.hh"
|
||||
#include "local-store.hh"
|
||||
#include "util.hh"
|
||||
#include "serialise.hh"
|
||||
#include "worker-protocol.hh"
|
||||
#include "archive.hh"
|
||||
#include "globals.hh"
|
||||
|
||||
#include <iostream>
|
||||
#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;
|
||||
|
||||
|
||||
#ifndef SIGPOLL
|
||||
#define SIGPOLL SIGIO
|
||||
#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(string((char *) buf, count), to);
|
||||
} 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);
|
||||
|
||||
if (select(socket + 1, &fds, 0, 0, &timeout) == -1)
|
||||
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;
|
||||
if (read(socket, &c, 1) != 0)
|
||||
throw Error("EOF expected (protocol error?)");
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
|
||||
/* A SIGPOLL signal is received when data is available on the client
|
||||
communication scoket, 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)
|
||||
{
|
||||
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;
|
||||
write(STDERR_FILENO, "SIGPOLL\n", 8);
|
||||
}
|
||||
} else {
|
||||
string s = "spurious SIGPOLL\n";
|
||||
write(STDERR_FILENO, s.c_str(), s.size());
|
||||
}
|
||||
}
|
||||
catch (Error & e) {
|
||||
/* Shouldn't happen. */
|
||||
write(STDERR_FILENO, e.msg().c_str(), e.msg().size());
|
||||
abort();
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void setSigPollAction(bool enable)
|
||||
{
|
||||
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");
|
||||
}
|
||||
|
||||
|
||||
/* 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 = "")
|
||||
{
|
||||
/* 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);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void performOp(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: {
|
||||
Path path = readStorePath(from);
|
||||
startWork();
|
||||
bool result = store->isValidPath(path);
|
||||
stopWork();
|
||||
writeInt(result, to);
|
||||
break;
|
||||
}
|
||||
|
||||
case wopHasSubstitutes: {
|
||||
Path path = readStorePath(from);
|
||||
startWork();
|
||||
bool result = store->hasSubstitutes(path);
|
||||
stopWork();
|
||||
writeInt(result, to);
|
||||
break;
|
||||
}
|
||||
|
||||
case wopQueryPathHash: {
|
||||
Path path = readStorePath(from);
|
||||
startWork();
|
||||
Hash hash = store->queryPathHash(path);
|
||||
stopWork();
|
||||
writeString(printHash(hash), to);
|
||||
break;
|
||||
}
|
||||
|
||||
case wopQueryReferences:
|
||||
case wopQueryReferrers: {
|
||||
Path path = readStorePath(from);
|
||||
startWork();
|
||||
PathSet paths;
|
||||
if (op == wopQueryReferences)
|
||||
store->queryReferences(path, paths);
|
||||
else
|
||||
store->queryReferrers(path, paths);
|
||||
stopWork();
|
||||
writeStringSet(paths, to);
|
||||
break;
|
||||
}
|
||||
|
||||
case wopAddToStore: {
|
||||
/* !!! uberquick hack */
|
||||
string baseName = readString(from);
|
||||
bool fixed = readInt(from) == 1;
|
||||
bool recursive = readInt(from) == 1;
|
||||
string hashAlgo = readString(from);
|
||||
|
||||
Path tmp = createTempDir();
|
||||
Path tmp2 = tmp + "/" + baseName;
|
||||
restorePath(tmp2, from);
|
||||
|
||||
startWork();
|
||||
Path path = store->addToStore(tmp2, fixed, recursive, hashAlgo);
|
||||
stopWork();
|
||||
|
||||
writeString(path, to);
|
||||
|
||||
deletePath(tmp);
|
||||
break;
|
||||
}
|
||||
|
||||
case wopAddTextToStore: {
|
||||
string suffix = readString(from);
|
||||
string s = readString(from);
|
||||
PathSet refs = readStorePaths(from);
|
||||
startWork();
|
||||
Path path = store->addTextToStore(suffix, s, refs);
|
||||
stopWork();
|
||||
writeString(path, to);
|
||||
break;
|
||||
}
|
||||
|
||||
case wopBuildDerivations: {
|
||||
PathSet drvs = readStorePaths(from);
|
||||
startWork();
|
||||
store->buildDerivations(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: {
|
||||
GCAction action = (GCAction) readInt(from);
|
||||
PathSet pathsToDelete = readStorePaths(from);
|
||||
bool ignoreLiveness = readInt(from);
|
||||
|
||||
PathSet result;
|
||||
unsigned long long bytesFreed;
|
||||
|
||||
startWork();
|
||||
if (ignoreLiveness)
|
||||
throw Error("you are not allowed to ignore liveness");
|
||||
store->collectGarbage(action, pathsToDelete, ignoreLiveness,
|
||||
result, bytesFreed);
|
||||
stopWork();
|
||||
|
||||
writeStringSet(result, to);
|
||||
writeInt(bytesFreed & 0xffffffff, to);
|
||||
writeInt(bytesFreed >> 32, to);
|
||||
|
||||
break;
|
||||
}
|
||||
|
||||
default:
|
||||
throw Error(format("invalid operation %1%") % op);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void processConnection()
|
||||
{
|
||||
canSendStderr = false;
|
||||
myPid = getpid();
|
||||
writeToStderr = tunnelStderr;
|
||||
|
||||
/* 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) | FASYNC) == -1)
|
||||
throw SysError("F_SETFL");
|
||||
|
||||
/* Exchange the greeting. */
|
||||
unsigned int magic = readInt(from);
|
||||
if (magic != WORKER_MAGIC_1) throw Error("protocol mismatch");
|
||||
verbosity = (Verbosity) readInt(from);
|
||||
writeInt(WORKER_MAGIC_2, to);
|
||||
|
||||
/* Send startup error messages to the client. */
|
||||
startWork();
|
||||
|
||||
try {
|
||||
|
||||
/* Prevent users from doing something very dangerous. */
|
||||
if (geteuid() == 0 &&
|
||||
querySetting("build-users-group", "") == "")
|
||||
throw Error("if you run `nix-worker' as root, then you MUST set `build-users-group'!");
|
||||
|
||||
/* Open the store. */
|
||||
store = boost::shared_ptr<StoreAPI>(new LocalStore(true));
|
||||
|
||||
stopWork();
|
||||
|
||||
} catch (Error & e) {
|
||||
stopWork(false, e.msg());
|
||||
return;
|
||||
}
|
||||
|
||||
/* Process client requests. */
|
||||
unsigned int opCount = 0;
|
||||
|
||||
while (true) {
|
||||
WorkerOp op;
|
||||
try {
|
||||
op = (WorkerOp) readInt(from);
|
||||
} catch (EndOfFile & e) {
|
||||
break;
|
||||
}
|
||||
|
||||
opCount++;
|
||||
|
||||
try {
|
||||
performOp(from, to, op);
|
||||
} catch (Error & e) {
|
||||
stopWork(false, e.msg());
|
||||
}
|
||||
|
||||
assert(!canSendStderr);
|
||||
};
|
||||
|
||||
printMsg(lvlError, format("%1% worker 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");
|
||||
}
|
||||
|
||||
|
||||
static void daemonLoop()
|
||||
{
|
||||
/* Get rid of children automatically; don't let them become
|
||||
zombies. */
|
||||
setSigChldAction(true);
|
||||
|
||||
/* Create and bind to a Unix domain socket. */
|
||||
AutoCloseFD fdSocket = socket(PF_UNIX, SOCK_STREAM, 0);
|
||||
if (fdSocket == -1)
|
||||
throw SysError("cannot create Unix domain socket");
|
||||
|
||||
string socketPath = nixStateDir + DEFAULT_SOCKET_PATH;
|
||||
|
||||
struct sockaddr_un addr;
|
||||
addr.sun_family = AF_UNIX;
|
||||
if (socketPath.size() >= sizeof(addr.sun_path))
|
||||
throw Error(format("socket path `%1%' is too long") % socketPath);
|
||||
strcpy(addr.sun_path, socketPath.c_str());
|
||||
|
||||
unlink(socketPath.c_str());
|
||||
|
||||
/* Make sure that the socket is created with 0666 permission
|
||||
(everybody can connect). */
|
||||
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);
|
||||
|
||||
if (listen(fdSocket, 5) == -1)
|
||||
throw SysError(format("cannot listen on socket `%1%'") % socketPath);
|
||||
|
||||
/* Loop accepting connections. */
|
||||
while (1) {
|
||||
|
||||
try {
|
||||
/* Important: the server process *cannot* open the
|
||||
Berkeley DB environment, 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");
|
||||
|
||||
printMsg(lvlInfo, format("accepted connection %1%") % remote);
|
||||
|
||||
/* 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 worker. */
|
||||
if (setsid() == -1)
|
||||
throw SysError(format("creating a new session"));
|
||||
|
||||
/* Restore normal handling of SIGCHLD. */
|
||||
setSigChldAction(false);
|
||||
|
||||
/* Handle the connection. */
|
||||
from.fd = remote;
|
||||
to.fd = remote;
|
||||
processConnection();
|
||||
|
||||
} catch (std::exception & e) {
|
||||
std::cerr << format("child error: %1%\n") % e.what();
|
||||
}
|
||||
exit(0);
|
||||
}
|
||||
|
||||
} catch (Interrupted & e) {
|
||||
throw;
|
||||
} catch (Error & e) {
|
||||
printMsg(lvlError, format("error processing connection: %1%") % e.msg());
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void run(Strings args)
|
||||
{
|
||||
bool slave = false;
|
||||
bool daemon = false;
|
||||
|
||||
for (Strings::iterator i = args.begin(); i != args.end(); ) {
|
||||
string arg = *i++;
|
||||
if (arg == "--slave") slave = true;
|
||||
if (arg == "--daemon") daemon = true;
|
||||
}
|
||||
|
||||
if (slave) {
|
||||
/* This prevents us from receiving signals from the terminal
|
||||
when we're running in setuid mode. */
|
||||
if (setsid() == -1)
|
||||
throw SysError(format("creating a new session"));
|
||||
|
||||
processConnection();
|
||||
}
|
||||
|
||||
else if (daemon) {
|
||||
if (setuidMode)
|
||||
throw Error("daemon cannot be started in setuid mode");
|
||||
chdir("/");
|
||||
daemonLoop();
|
||||
}
|
||||
|
||||
else
|
||||
throw Error("must be run in either --slave or --daemon mode");
|
||||
}
|
||||
|
||||
|
||||
#include "help.txt.hh"
|
||||
|
||||
void printHelp()
|
||||
{
|
||||
std::cout << string((char *) helpText, sizeof helpText);
|
||||
}
|
||||
|
||||
|
||||
string programId = "nix-worker";
|
||||
Loading…
Add table
Add a link
Reference in a new issue