int pipefd[2];
if (pipe2(pipefd, O_CLOEXEC)) {
- // TODO log error
+ log(LogLevel::ERROR, service_name, ": can't create status check pipe: ", strerror(errno));
return false;
}
-
- // Set up the argument array and other data now (before fork), in case memory allocation fails.
-
- auto args = cmd.data();
-
+
const char * logfile = this->logfile.c_str();
if (*logfile == 0) {
logfile = "/dev/null";
}
+ bool child_status_registered = false;
+ ControlConn *control_conn = nullptr;
+
+ int control_socket[2] = {-1, -1};
+ if (onstart_flags.pass_cs_fd) {
+ if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, /* protocol */ 0, control_socket)) {
+ log(LogLevel::ERROR, service_name, ": can't create control socket: ", strerror(errno));
+ goto out_p;
+ }
+
+ // Make the server side socket close-on-exec:
+ int fdflags = fcntl(control_socket[0], F_GETFD);
+ fcntl(control_socket[0], F_SETFD, fdflags | FD_CLOEXEC);
+
+ try {
+ control_conn = new ControlConn(&eventLoop, service_set, control_socket[0]);
+ }
+ catch (std::exception &exc) {
+ log(LogLevel::ERROR, service_name, ": can't launch process; out of memory");
+ goto out_cs;
+ }
+ }
+
+ // Set up complete, now fork and exec:
+
pid_t forkpid;
- bool child_status_registered = false;
try {
child_status_listener.addWatch(eventLoop, pipefd[0], IN_EVENTS);
child_status_registered = true;
forkpid = child_listener.fork(eventLoop);
}
- catch (...) {
- if (child_status_registered) {
- child_status_listener.deregister(eventLoop);
+ catch (std::exception &e) {
+ log(LogLevel::ERROR, service_name, ": Could not fork: ", e.what());
+ goto out_cs_h;
+ }
+
+ if (forkpid == 0) {
+ run_child_proc(cmd.data(), logfile, on_console, pipefd[1], control_socket[1]);
+ }
+ else {
+ // Parent process
+ close(pipefd[1]); // close the 'other end' fd
+ if (control_socket[1] != -1) {
+ close(control_socket[1]);
}
- close(pipefd[0]);
- close(pipefd[1]);
- return false;
+ pid = forkpid;
+
+ waiting_for_execstat = true;
+ return true;
}
+ // Failure exit:
+
+ out_cs_h:
+ if (child_status_registered) {
+ child_status_listener.deregister(eventLoop);
+ }
+
+ if (onstart_flags.pass_cs_fd) {
+ delete control_conn;
+
+ out_cs:
+ close(control_socket[0]);
+ close(control_socket[1]);
+ }
+
+ out_p:
+ close(pipefd[0]);
+ close(pipefd[1]);
+
+ return false;
+}
+
+void ServiceRecord::run_child_proc(const char * const *args, const char *logfile, bool on_console,
+ int wpipefd, int csfd) noexcept
+{
+ // Child process. Must not allocate memory (or otherwise risk throwing any exception)
+ // from here until exit().
+
// If the console already has a session leader, presumably it is us. On the other hand
// if it has no session leader, and we don't create one, then control inputs such as
// ^C will have no effect.
bool do_set_ctty = (tcgetsid(0) == -1);
+
+ // Copy signal mask, but unmask signals that we masked on startup. For the moment, we'll
+ // also block all signals, since apparently dup() can be interrupted (!!! really, POSIX??).
+ sigset_t sigwait_set;
+ sigset_t sigall_set;
+ sigfillset(&sigall_set);
+ sigprocmask(SIG_SETMASK, &sigall_set, &sigwait_set);
+ sigdelset(&sigwait_set, SIGCHLD);
+ sigdelset(&sigwait_set, SIGINT);
+ sigdelset(&sigwait_set, SIGTERM);
+
+ constexpr int bufsz = ((CHAR_BIT * sizeof(pid_t)) / 3 + 2) + 11;
+ // "LISTEN_PID=" - 11 characters; the expression above gives a conservative estimate
+ // on the maxiumum number of bytes required for LISTEN=xxx, including nul terminator,
+ // where xxx is a pid_t in decimal (i.e. one decimal digit is worth just over 3 bits).
+ char nbuf[bufsz];
+
+ // "DINIT_CS_FD=" - 12 bytes. (we -1 from sizeof(int) in account of sign bit).
+ constexpr int csenvbufsz = ((CHAR_BIT * sizeof(int) - 1) / 3 + 2) + 12;
+ char csenvbuf[csenvbufsz];
+
+ int minfd = (socket_fd == -1) ? 3 : 4;
- if (forkpid == 0) {
- // Child process. Must not allocate memory (or otherwise risk throwing any exception)
- // from here until exit().
- // TODO: we may need an equivalent for the following:
- // ev_default_destroy(); // won't need that on this side, free up fds.
+ // Move wpipefd/csfd to another fd if necessary
+ if (wpipefd < minfd) {
+ wpipefd = fcntl(wpipefd, F_DUPFD_CLOEXEC, minfd);
+ if (wpipefd == -1) goto failure_out;
+ }
+
+ if (csfd != -1 && csfd < minfd) {
+ csfd = fcntl(csfd, F_DUPFD, minfd);
+ if (csfd == -1) goto failure_out;
+ }
+
+ if (socket_fd != -1) {
- // Copy signal mask, but unmask signals that we masked on startup. For the moment, we'll
- // also block all signals, since apparently dup() can be interrupted (!!! really, POSIX??).
- sigset_t sigwait_set;
- sigset_t sigall_set;
- sigfillset(&sigall_set);
- sigprocmask(SIG_SETMASK, &sigall_set, &sigwait_set);
- sigdelset(&sigwait_set, SIGCHLD);
- sigdelset(&sigwait_set, SIGINT);
- sigdelset(&sigwait_set, SIGTERM);
+ if (dup2(socket_fd, 3) == -1) goto failure_out;
+ if (socket_fd != 3) {
+ close(socket_fd);
+ }
- constexpr int bufsz = ((CHAR_BIT * sizeof(pid_t)) / 3 + 2) + 11;
- // "LISTEN_PID=" - 11 characters; the expression above gives a conservative estimate
- // on the maxiumum number of bytes required for LISTEN=xxx, including nul terminator,
- // where xxx is a pid_t in decimal (i.e. one decimal digit is worth just over 3 bits).
- char nbuf[bufsz];
+ if (putenv(const_cast<char *>("LISTEN_FDS=1"))) goto failure_out;
+ snprintf(nbuf, bufsz, "LISTEN_PID=%jd", static_cast<intmax_t>(getpid()));
+ if (putenv(nbuf)) goto failure_out;
+ }
+
+ if (csfd != -1) {
+ snprintf(csenvbuf, csenvbufsz, "DINIT_CS_FD=%d", csfd);
+ if (putenv(csenvbuf)) goto failure_out;
+ }
- if (socket_fd != -1) {
-
- if (pipefd[1] == 3) {
- dup3(pipefd[1], 4, O_CLOEXEC);
- }
-
- dup2(socket_fd, 3);
- if (socket_fd != 3) {
- close(socket_fd);
- }
-
- if (putenv(const_cast<char *>("LISTEN_FDS=1"))) goto failure_out;
-
- snprintf(nbuf, bufsz, "LISTEN_PID=%jd", static_cast<intmax_t>(getpid()));
-
- if (putenv(nbuf)) goto failure_out;
- }
+ if (! on_console) {
+ // Re-set stdin, stdout, stderr
+ close(0); close(1); close(2);
- if (! on_console) {
- while (pipefd[1] < 3) {
- pipefd[1] = dup(pipefd[1]);
- if (pipefd[1] == -1) goto failure_out;
+ if (open("/dev/null", O_RDONLY) == 0) {
+ // stdin = 0. That's what we should have; proceed with opening
+ // stdout and stderr.
+ if (open(logfile, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR) != 1) {
+ goto failure_out;
}
-
- // Re-set stdin, stdout, stderr
- close(0); close(1); close(2);
-
- if (open("/dev/null", O_RDONLY) == 0) {
- // stdin = 0. That's what we should have; proceed with opening
- // stdout and stderr.
- if (open(logfile, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR) != 1) {
- goto failure_out;
- }
- if (dup2(1, 2) != 2) {
- goto failure_out;
- }
+ if (dup2(1, 2) != 2) {
+ goto failure_out;
}
- else goto failure_out;
}
- else {
- // "run on console" - run as a foreground job on the terminal/console device
-
- if (do_set_ctty) {
- // Disable suspend (^Z) (and on some systems, delayed suspend / ^Y)
- signal(SIGTSTP, SIG_IGN);
-
- // Become session leader
- setsid();
- ioctl(0, TIOCSCTTY, 0);
- }
- setpgid(0,0);
- tcsetpgrp(0, getpgrp());
- }
-
- sigprocmask(SIG_SETMASK, &sigwait_set, nullptr);
-
- execvp(exec_arg_parts[0], const_cast<char **>(args));
-
- // If we got here, the exec failed:
- failure_out:
- int exec_status = errno;
- write(pipefd[1], &exec_status, sizeof(int));
- _exit(0);
+ else goto failure_out;
}
else {
- // Parent process
- close(pipefd[1]); // close the 'other end' fd
- pid = forkpid;
-
- waiting_for_execstat = true;
- return true;
+ // "run on console" - run as a foreground job on the terminal/console device
+
+ if (do_set_ctty) {
+ // Disable suspend (^Z) (and on some systems, delayed suspend / ^Y)
+ signal(SIGTSTP, SIG_IGN);
+
+ // Become session leader
+ setsid();
+ ioctl(0, TIOCSCTTY, 0);
+ }
+ setpgid(0,0);
+ tcsetpgrp(0, getpgrp());
}
+
+ sigprocmask(SIG_SETMASK, &sigwait_set, nullptr);
+
+ execvp(args[0], const_cast<char **>(args));
+
+ // If we got here, the exec failed:
+ failure_out:
+ int exec_status = errno;
+ write(wpipefd, &exec_status, sizeof(int));
+ _exit(0);
}
// Mark this and all dependent services as force-stopped.
projects / oweals / dinit.git / commitdiff