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)
31 static 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: stable/10/lib/libc/gen/daemon.c 287480 2015-09-05 08:55:51Z kib $");
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
46 int
daemon(int nochdir,int noclose)47 daemon(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