1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char sccsid[] = "@(#)daemon.c	8.1 (Berkeley) 6/4/93";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD$");
35
36#include "namespace.h"
37#include <errno.h>
38#include <fcntl.h>
39#include <paths.h>
40#include <stdlib.h>
41#include <signal.h>
42#include <unistd.h>
43#include "un-namespace.h"
44#include "libc_private.h"
45
46int
47daemon(int nochdir, int noclose)
48{
49	struct sigaction osa, sa;
50	int fd;
51	pid_t newgrp;
52	int oerrno;
53	int osa_ok;
54
55	/* A SIGHUP may be thrown when the parent exits below. */
56	sigemptyset(&sa.sa_mask);
57	sa.sa_handler = SIG_IGN;
58	sa.sa_flags = 0;
59	osa_ok = __libc_sigaction(SIGHUP, &sa, &osa);
60
61	switch (fork()) {
62	case -1:
63		return (-1);
64	case 0:
65		break;
66	default:
67		/*
68		 * A fine point:  _exit(0), not exit(0), to avoid triggering
69		 * atexit(3) processing
70		 */
71		_exit(0);
72	}
73
74	newgrp = setsid();
75	oerrno = errno;
76	if (osa_ok != -1)
77		__libc_sigaction(SIGHUP, &osa, NULL);
78
79	if (newgrp == -1) {
80		errno = oerrno;
81		return (-1);
82	}
83
84	if (!nochdir)
85		(void)chdir("/");
86
87	if (!noclose && (fd = _open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
88		(void)_dup2(fd, STDIN_FILENO);
89		(void)_dup2(fd, STDOUT_FILENO);
90		(void)_dup2(fd, STDERR_FILENO);
91		if (fd > 2)
92			(void)_close(fd);
93	}
94	return (0);
95}
96