1 /* daemon implementation for uClibc
2 *
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * 3. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
16 * ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
17 *
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 /*
36 * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
37 *
38 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
39 * Modified for uClibc by Erik Andersen <andersen@uclibc.org>
40 */
41
42 #include <stdio.h>
43 #include <features.h>
44 #include <fcntl.h>
45 #include <paths.h>
46 #include <signal.h>
47 #include <unistd.h>
48 #include <not-cancel.h>
49 #include <errno.h>
50
51 #ifdef __UCLIBC_HAS_THREADS_NATIVE__
52 #include <sys/stat.h>
53 #endif
54
55 #define STAT stat64
56 #define FSTAT fstat64
57
58 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
59
60 #ifndef __ARCH_USE_MMU__
61 #include <sys/syscall.h>
62 #include <sched.h>
63 /* use clone() to get fork() like behavior here -- we just want to disassociate
64 * from the controlling terminal
65 */
_fork_parent(void)66 static inline pid_t _fork_parent(void)
67 {
68 INTERNAL_SYSCALL_DECL(err);
69 register long ret = INTERNAL_SYSCALL(clone, err, 2, CLONE_VM, 0);
70 if (ret > 0)
71 /* parent needs to die now w/out touching stack */
72 INTERNAL_SYSCALL(exit, err, 1, 0);
73 return ret;
74 }
fork_parent(void)75 static inline pid_t fork_parent(void)
76 {
77 /* Block all signals to keep the parent from using the stack */
78 pid_t ret;
79 sigset_t new_set, old_set;
80 sigfillset(&new_set);
81 sigprocmask(SIG_BLOCK, &new_set, &old_set);
82 ret = _fork_parent();
83 sigprocmask(SIG_SETMASK, &old_set, NULL);
84 return ret;
85 }
86 #else
fork_parent(void)87 static inline pid_t fork_parent(void)
88 {
89 switch (fork()) {
90 case -1: return -1;
91 case 0: return 0;
92 default: _exit(0);
93 }
94 }
95 #endif
96
daemon(int nochdir,int noclose)97 int daemon(int nochdir, int noclose)
98 {
99 int fd;
100
101 if (fork_parent() == -1)
102 return -1;
103
104 if (setsid() == -1)
105 return -1;
106
107 if (!nochdir)
108 chdir("/");
109
110 if (!noclose)
111 {
112 struct STAT st;
113
114 if ((fd = open_not_cancel_2(_PATH_DEVNULL, O_RDWR)) != -1
115 && (__builtin_expect (FSTAT (fd, &st), 0) == 0))
116 {
117 if (__builtin_expect (S_ISCHR (st.st_mode), 1) != 0) {
118 dup2(fd, STDIN_FILENO);
119 dup2(fd, STDOUT_FILENO);
120 dup2(fd, STDERR_FILENO);
121 if (fd > 2)
122 close(fd);
123 } else {
124 /* We must set an errno value since no
125 function call actually failed. */
126 close_not_cancel_no_status (fd);
127 __set_errno (ENODEV);
128 return -1;
129 }
130 } else {
131 close_not_cancel_no_status (fd);
132 return -1;
133 }
134 }
135 return 0;
136 }
137 #endif
138