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 * 3. 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 * @(#)daemon.c 8.1 (Berkeley) 6/4/93
30 * $FreeBSD: src/lib/libc/gen/daemon.c,v 1.8 2007/01/09 00:27:53 imp Exp $
31 * $DragonFly: src/lib/libc/gen/daemon.c,v 1.4 2005/04/26 15:57:39 joerg Exp $
32 */
33
34 #include "namespace.h"
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <paths.h>
38 #include <stdlib.h>
39 #include <signal.h>
40 #include <unistd.h>
41 #include "un-namespace.h"
42
43 int
daemon(int nochdir,int noclose)44 daemon(int nochdir, int noclose)
45 {
46 struct sigaction osa, sa;
47 int fd;
48 pid_t newgrp;
49 int oerrno;
50 int osa_ok;
51
52 /* A SIGHUP may be thrown when the parent exits below. */
53 sigemptyset(&sa.sa_mask);
54 sa.sa_handler = SIG_IGN;
55 sa.sa_flags = 0;
56 osa_ok = _sigaction(SIGHUP, &sa, &osa);
57
58 switch (fork()) {
59 case -1:
60 return (-1);
61 case 0:
62 break;
63 default:
64 _exit(0);
65 }
66
67 newgrp = setsid();
68 oerrno = errno;
69 if (osa_ok != -1)
70 _sigaction(SIGHUP, &osa, NULL);
71
72 if (newgrp == -1) {
73 errno = oerrno;
74 return (-1);
75 }
76
77 if (!nochdir)
78 chdir("/");
79
80 if (!noclose && (fd = _open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
81 _dup2(fd, STDIN_FILENO);
82 _dup2(fd, STDOUT_FILENO);
83 _dup2(fd, STDERR_FILENO);
84 if (fd > 2)
85 _close(fd);
86 }
87 return (0);
88 }
89