Ejemplo n.º 1
0
/*
 * blocking_thread - thread functions have WINAPI calling convention
 */
void *
blocking_thread(
	void *	ThreadArg
	)
{
	blocking_child *c;

	c = ThreadArg;
	exit_worker(blocking_child_common(c));

	/* NOTREACHED */
	return 0;
}
Ejemplo n.º 2
0
static void
fork_blocking_child(
	blocking_child *	c
	)
{
	static int	atexit_installed;
	static int	blocking_pipes[4] = { -1, -1, -1, -1 };
	int		rc;
	int		was_pipe;
	int		is_pipe;
	int		saved_errno = 0;
	int		childpid;
	int		keep_fd;
	int		fd;

	/*
	 * parent and child communicate via a pair of pipes.
	 * 
	 * 0 child read request
	 * 1 parent write request
	 * 2 parent read response
	 * 3 child write response
	 */
	if (-1 == c->req_write_pipe) {
		rc = pipe_socketpair(&blocking_pipes[0], &was_pipe);
		if (0 != rc) {
			saved_errno = errno;
		} else {
			rc = pipe_socketpair(&blocking_pipes[2], &is_pipe);
			if (0 != rc) {
				saved_errno = errno;
				close(blocking_pipes[0]);
				close(blocking_pipes[1]);
			} else {
				INSIST(was_pipe == is_pipe);
			}
		}
		if (0 != rc) {
			errno = saved_errno;
			msyslog(LOG_ERR, "unable to create worker pipes: %m");
			exit(1);
		}

		/*
		 * Move the descriptors the parent will keep open out of the
		 * low descriptors preferred by C runtime buffered FILE *.
		 */
		c->req_write_pipe = move_fd(blocking_pipes[1]);
		c->resp_read_pipe = move_fd(blocking_pipes[2]);
		/*
		 * wake any worker child on orderly shutdown of the
		 * daemon so that it can notice the broken pipes and
		 * go away promptly.
		 */
		if (!atexit_installed) {
			atexit(&send_worker_home_atexit);
			atexit_installed = TRUE;
		}
	}

#ifdef HAVE_DROPROOT
	/* defer the fork until after root is dropped */
	if (droproot && !root_dropped)
		return;
#endif
	if (syslog_file != NULL)
		fflush(syslog_file);
	fflush(stdout);
	fflush(stderr);

	signal_no_reset(SIGCHLD, SIG_IGN);

	childpid = fork();
	if (-1 == childpid) {
		msyslog(LOG_ERR, "unable to fork worker: %m");
		exit(1);
	}

	if (childpid) {
		/* this is the parent */
		TRACE(1, ("forked worker child (pid %d)\n", childpid));
		c->pid = childpid;
		c->ispipe = is_pipe;

		/* close the child's pipe descriptors. */
		close(blocking_pipes[0]);
		close(blocking_pipes[3]);

		memset(blocking_pipes, -1, sizeof(blocking_pipes));

		/* wire into I/O loop */
		(*addremove_io_fd)(c->resp_read_pipe, is_pipe, FALSE);

		return;		/* parent returns */
	}

	/*
	 * The parent gets the child pid as the return value of fork().
	 * The child must work for it.
	 */
	c->pid = getpid();
	worker_process = TRUE;

	/*
	 * In the child, close all files except stdin, stdout, stderr,
	 * and the two child ends of the pipes.
	 */
	DEBUG_INSIST(-1 == c->req_read_pipe);
	DEBUG_INSIST(-1 == c->resp_write_pipe);
	c->req_read_pipe = blocking_pipes[0];
	c->resp_write_pipe = blocking_pipes[3];

	kill_asyncio(0);
	closelog();
	if (syslog_file != NULL) {
		fclose(syslog_file);
		syslog_file = NULL;
		syslogit = TRUE;
	}
	keep_fd = max(c->req_read_pipe, c->resp_write_pipe);
	for (fd = 3; fd < keep_fd; fd++)
		if (fd != c->req_read_pipe && 
		    fd != c->resp_write_pipe)
			close(fd);
	close_all_beyond(keep_fd);
	/*
	 * We get signals from refclock serial I/O on NetBSD in the
	 * worker if we do not reset SIGIO's handler to the default.
	 * It is not conditionalized for NetBSD alone because on
	 * systems where it is not needed, it is harmless, and that
	 * allows us to handle unknown others with NetBSD behavior.
	 * [Bug 1386]
	 */
#if defined(USE_SIGIO)
	signal_no_reset(SIGIO, SIG_DFL);
#elif defined(USE_SIGPOLL)
	signal_no_reset(SIGPOLL, SIG_DFL);
#endif
	signal_no_reset(SIGHUP, worker_sighup);
	init_logging("ntp_intres", 0, FALSE);
	setup_logfile(NULL);

	/*
	 * And now back to the portable code
	 */
	exit_worker(blocking_child_common(c));
}