1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1988, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#if defined(LIBC_SCCS) && !defined(lint)
33static char sccsid[] = "@(#)system.c	8.1 (Berkeley) 6/4/93";
34#endif /* LIBC_SCCS and not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD$");
37
38#include "namespace.h"
39#include <sys/types.h>
40#include <sys/wait.h>
41#include <signal.h>
42#include <stdlib.h>
43#include <stddef.h>
44#include <string.h>
45#include <unistd.h>
46#include <paths.h>
47#include <errno.h>
48#include "un-namespace.h"
49#include "libc_private.h"
50
51#pragma weak system
52int
53system(const char *command)
54{
55
56	return (((int (*)(const char *))
57	    __libc_interposing[INTERPOS_system])(command));
58}
59
60int
61__libc_system(const char *command)
62{
63	pid_t pid, savedpid;
64	int pstat;
65	struct sigaction ign, intact, quitact;
66	sigset_t newsigblock, oldsigblock;
67
68	if (!command)		/* just checking... */
69		return(1);
70
71	(void)sigemptyset(&newsigblock);
72	(void)sigaddset(&newsigblock, SIGCHLD);
73	(void)sigaddset(&newsigblock, SIGINT);
74	(void)sigaddset(&newsigblock, SIGQUIT);
75	(void)__libc_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
76	switch(pid = vfork()) {
77	/*
78	 * In the child, use unwrapped syscalls.  libthr is in
79	 * undefined state after vfork().
80	 */
81	case -1:			/* error */
82		(void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
83		return (-1);
84	case 0:				/* child */
85		/*
86		 * Restore original signal dispositions and exec the command.
87		 */
88		(void)__sys_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
89		execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
90		_exit(127);
91	}
92	/*
93	 * If we are running means that the child has either completed
94	 * its execve, or has failed.
95	 * Block SIGINT/QUIT because sh -c handles it and wait for
96	 * it to clean up.
97	 */
98	memset(&ign, 0, sizeof(ign));
99	ign.sa_handler = SIG_IGN;
100	(void)sigemptyset(&ign.sa_mask);
101	(void)__libc_sigaction(SIGINT, &ign, &intact);
102	(void)__libc_sigaction(SIGQUIT, &ign, &quitact);
103	savedpid = pid;
104	do {
105		pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
106	} while (pid == -1 && errno == EINTR);
107	(void)__libc_sigaction(SIGINT, &intact, NULL);
108	(void)__libc_sigaction(SIGQUIT,  &quitact, NULL);
109	(void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
110	return (pid == -1 ? -1 : pstat);
111}
112
113__weak_reference(__libc_system, __system);
114__weak_reference(__libc_system, _system);
115