1/*
2 * Copyright (c) 1988, 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[] = "@(#)system.c	8.1 (Berkeley) 6/4/93";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: src/lib/libc/stdlib/system.c,v 1.11 2007/01/09 00:28:10 imp Exp $");
35
36#include "namespace.h"
37#include <sys/types.h>
38#include <sys/wait.h>
39#include <signal.h>
40#include <stdlib.h>
41#include <stddef.h>
42#include <unistd.h>
43#include <spawn.h>
44#include <paths.h>
45#include <errno.h>
46#include "un-namespace.h"
47#include "libc_private.h"
48
49#include <crt_externs.h>
50#define environ (*_NSGetEnviron())
51
52#if __DARWIN_UNIX03
53#include <pthread.h>
54
55static pthread_mutex_t __systemfn_mutex = PTHREAD_MUTEX_INITIALIZER;
56extern int __unix_conforming;
57#endif /* __DARWIN_UNIX03 */
58
59int
60__system(command)
61	const char *command;
62{
63	pid_t pid, savedpid;
64	int pstat, err;
65	struct sigaction ign, intact, quitact;
66	sigset_t newsigblock, oldsigblock, defaultsig;
67	posix_spawnattr_t attr;
68	short flags = POSIX_SPAWN_SETSIGMASK;
69	const char *argv[] = {"sh", "-c", command, NULL};
70
71#if __DARWIN_UNIX03
72	if (__unix_conforming == 0)
73		__unix_conforming = 1;
74#ifdef VARIANT_CANCELABLE
75	pthread_testcancel();
76#endif /* VARIANT_CANCELABLE */
77#endif /* __DARWIN_UNIX03 */
78
79	if (!command) {		/* just checking... */
80		if (access(_PATH_BSHELL, F_OK) == -1)	/* if no sh or no access */
81			return(0);
82		else
83			return(1);
84	}
85
86	if ((err = posix_spawnattr_init(&attr)) != 0) {
87		errno = err;
88		return -1;
89	}
90	(void)sigemptyset(&defaultsig);
91
92#if __DARWIN_UNIX03
93	pthread_mutex_lock(&__systemfn_mutex);
94#endif /* __DARWIN_UNIX03 */
95	/*
96	 * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
97	 * existing signal dispositions.
98	 */
99	ign.sa_handler = SIG_IGN;
100	(void)sigemptyset(&ign.sa_mask);
101	ign.sa_flags = 0;
102	(void)_sigaction(SIGINT, &ign, &intact);
103	if (intact.sa_handler != SIG_IGN) {
104		sigaddset(&defaultsig, SIGINT);
105		flags |= POSIX_SPAWN_SETSIGDEF;
106	}
107	(void)_sigaction(SIGQUIT, &ign, &quitact);
108	if (quitact.sa_handler != SIG_IGN) {
109		sigaddset(&defaultsig, SIGQUIT);
110		flags |= POSIX_SPAWN_SETSIGDEF;
111	}
112	(void)sigemptyset(&newsigblock);
113	(void)sigaddset(&newsigblock, SIGCHLD);
114	(void)_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
115	(void)posix_spawnattr_setsigmask(&attr, &oldsigblock);
116	if (flags & POSIX_SPAWN_SETSIGDEF) {
117		(void)posix_spawnattr_setsigdefault(&attr, &defaultsig);
118	}
119	(void)posix_spawnattr_setflags(&attr, flags);
120
121	err = posix_spawn(&pid, _PATH_BSHELL, NULL, &attr, (char *const *)argv, environ);
122	(void)posix_spawnattr_destroy(&attr);
123	if (err == 0) {
124		savedpid = pid;
125		do {
126			pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
127		} while (pid == -1 && errno == EINTR);
128		if (pid == -1) pstat = -1;
129	} else if (err == ENOMEM || err == EAGAIN) { /* as if fork failed */
130		pstat = -1;
131	} else {
132		pstat = W_EXITCODE(127, 0); /* couldn't exec shell */
133	}
134
135	(void)_sigaction(SIGINT, &intact, NULL);
136	(void)_sigaction(SIGQUIT,  &quitact, NULL);
137	(void)_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
138#if __DARWIN_UNIX03
139	pthread_mutex_unlock(&__systemfn_mutex);
140#endif /* __DARWIN_UNIX03 */
141	return(pstat);
142}
143
144__weak_reference(__system, system);
145__weak_reference(__system, _system);
146