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
34#include <errno.h>
35#include <fcntl.h>
36#include <paths.h>
37#include <unistd.h>
38#include <sys/stat.h>
39
40#include <device-nrs.h>
41#include <not-cancel.h>
42
43int
44daemon (int nochdir, int noclose)
45{
46 int fd;
47
48 switch (__fork()) {
49 case -1:
50 return (-1);
51 case 0:
52 break;
53 default:
54 _exit(0);
55 }
56
57 if (__setsid() == -1)
58 return (-1);
59
60 if (!nochdir)
61 (void)__chdir("/");
62
63 if (!noclose) {
64 struct stat64 st;
65
66 if ((fd = __open_nocancel(_PATH_DEVNULL, O_RDWR, 0)) != -1
67 && (__builtin_expect (__fstat64 (fd, &st), 0)
68 == 0)) {
69 if (__builtin_expect (S_ISCHR (st.st_mode), 1) != 0
70#if defined DEV_NULL_MAJOR && defined DEV_NULL_MINOR
71 && (st.st_rdev
72 == makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR))
73#endif
74 ) {
75 (void)__dup2(fd, STDIN_FILENO);
76 (void)__dup2(fd, STDOUT_FILENO);
77 (void)__dup2(fd, STDERR_FILENO);
78 if (fd > 2)
79 (void)__close (fd);
80 } else {
81 /* We must set an errno value since no
82 function call actually failed. */
83 __close_nocancel_nostatus (fd);
84 __set_errno (ENODEV);
85 return -1;
86 }
87 } else {
88 __close_nocancel_nostatus (fd);
89 return -1;
90 }
91 }
92 return (0);
93}
94