[mirror_frr.git] / lib / pid_output.c

/*
 * Process id output.
 * Copyright (C) 1998, 1999 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <zebra.h>
#include <fcntl.h>
#include <log.h>
#include "version.h"
#include "network.h"

#define PIDFILE_MASK 0644

pid_t pid_output(const char *path)
{
	int tmp;
	int fd;
	pid_t pid;
	char buf[16];
	struct flock lock;
	mode_t oldumask;

	pid = getpid();

	oldumask = umask(0777 & ~PIDFILE_MASK);
	fd = open(path, O_RDWR | O_CREAT, PIDFILE_MASK);
	if (fd < 0) {
		zlog_err("Can't create pid lock file %s (%s), exiting", path,
			 safe_strerror(errno));
		umask(oldumask);
		exit(1);
	} else {
		size_t pidsize;

		umask(oldumask);
		memset(&lock, 0, sizeof(lock));

		set_cloexec(fd);

		lock.l_type = F_WRLCK;
		lock.l_whence = SEEK_SET;

		if (fcntl(fd, F_SETLK, &lock) < 0) {
			zlog_err("Could not lock pid_file %s, exiting", path);
			exit(1);
		}

		sprintf(buf, "%d\n", (int)pid);
		pidsize = strlen(buf);
		if ((tmp = write(fd, buf, pidsize)) != (int)pidsize)
			zlog_err(
				"Could not write pid %d to pid_file %s, rc was %d: %s",
				(int)pid, path, tmp, safe_strerror(errno));
		else if (ftruncate(fd, pidsize) < 0)
			zlog_err(
				"Could not truncate pid_file %s to %u bytes: %s",
				path, (u_int)pidsize, safe_strerror(errno));
	}
	return pid;
}
Commit	Line	Data
718e3744	1	/*
	2	* Process id output.
	3	* Copyright (C) 1998, 1999 Kunihiro Ishiguro
	4	*
	5	* This file is part of GNU Zebra.
	6	*
	7	* GNU Zebra is free software; you can redistribute it and/or modify it
	8	* under the terms of the GNU General Public License as published by the
	9	* Free Software Foundation; either version 2, or (at your option) any
	10	* later version.
	11	*
	12	* GNU Zebra is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with GNU Zebra; see the file COPYING. If not, write to the Free
	19	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
ac4d0be5	20	* 02111-1307, USA.
718e3744	21	*/
	22
	23	#include <zebra.h>
e92fbaf2	24	#include <fcntl.h>
e92fbaf2	25	#include <log.h>
e5879ca1	26	#include "version.h"
2da59394	27	#include "network.h"
718e3744	28
7593fddf	29	#define PIDFILE_MASK 0644
202d08ca	30
ac4d0be5	31	pid_t pid_output(const char *path)
718e3744	32	{
ac4d0be5	33	int tmp;
	34	int fd;
	35	pid_t pid;
	36	char buf[16];
	37	struct flock lock;
	38	mode_t oldumask;
718e3744	39
ac4d0be5	40	pid = getpid();
718e3744	41
ac4d0be5	42	oldumask = umask(0777 & ~PIDFILE_MASK);
	43	fd = open(path, O_RDWR \| O_CREAT, PIDFILE_MASK);
	44	if (fd < 0) {
	45	zlog_err("Can't create pid lock file %s (%s), exiting", path,
	46	safe_strerror(errno));
	47	umask(oldumask);
	48	exit(1);
	49	} else {
	50	size_t pidsize;
e5879ca1	51
ac4d0be5	52	umask(oldumask);
ac4d0be5	53	memset(&lock, 0, sizeof(lock));
e92fbaf2	54
ac4d0be5	55	set_cloexec(fd);
2da59394	56
ac4d0be5	57	lock.l_type = F_WRLCK;
ac4d0be5	58	lock.l_whence = SEEK_SET;
e4eaf1d5	59
ac4d0be5	60	if (fcntl(fd, F_SETLK, &lock) < 0) {
	61	zlog_err("Could not lock pid_file %s, exiting", path);
	62	exit(1);
	63	}
e92fbaf2	64
ac4d0be5	65	sprintf(buf, "%d\n", (int)pid);
	66	pidsize = strlen(buf);
	67	if ((tmp = write(fd, buf, pidsize)) != (int)pidsize)
	68	zlog_err(
	69	"Could not write pid %d to pid_file %s, rc was %d: %s",
	70	(int)pid, path, tmp, safe_strerror(errno));
	71	else if (ftruncate(fd, pidsize) < 0)
	72	zlog_err(
	73	"Could not truncate pid_file %s to %u bytes: %s",
	74	path, (u_int)pidsize, safe_strerror(errno));
	75	}
	76	return pid;
718e3744	77	}