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)
33 static char sccsid[] = "@(#)system.c 8.1 (Berkeley) 6/4/93";
34 #endif /* LIBC_SCCS and not lint */
35 #include "namespace.h"
36 #include <sys/types.h>
37 #include <sys/wait.h>
38 #include <signal.h>
39 #include <stdlib.h>
40 #include <stddef.h>
41 #include <string.h>
42 #include <unistd.h>
43 #include <paths.h>
44 #include <errno.h>
45 #include "un-namespace.h"
46 #include "libc_private.h"
47
48 #pragma weak system
49 int
system(const char * command)50 system(const char *command)
51 {
52
53 return (((int (*)(const char *))
54 __libc_interposing[INTERPOS_system])(command));
55 }
56
57 int
__libc_system(const char * command)58 __libc_system(const char *command)
59 {
60 pid_t pid, savedpid;
61 int pstat;
62 struct sigaction ign, intact, quitact;
63 sigset_t newsigblock, oldsigblock;
64
65 if (!command) /* just checking... */
66 return(1);
67
68 (void)sigemptyset(&newsigblock);
69 (void)sigaddset(&newsigblock, SIGCHLD);
70 (void)sigaddset(&newsigblock, SIGINT);
71 (void)sigaddset(&newsigblock, SIGQUIT);
72 (void)__libc_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
73 switch(pid = vfork()) {
74 /*
75 * In the child, use unwrapped syscalls. libthr is in
76 * undefined state after vfork().
77 */
78 case -1: /* error */
79 (void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
80 return (-1);
81 case 0: /* child */
82 /*
83 * Restore original signal dispositions and exec the command.
84 */
85 (void)__sys_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
86 execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
87 _exit(127);
88 }
89 /*
90 * If we are running means that the child has either completed
91 * its execve, or has failed.
92 * Block SIGINT/QUIT because sh -c handles it and wait for
93 * it to clean up.
94 */
95 memset(&ign, 0, sizeof(ign));
96 ign.sa_handler = SIG_IGN;
97 (void)sigemptyset(&ign.sa_mask);
98 (void)__libc_sigaction(SIGINT, &ign, &intact);
99 (void)__libc_sigaction(SIGQUIT, &ign, &quitact);
100 savedpid = pid;
101 do {
102 pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
103 } while (pid == -1 && errno == EINTR);
104 (void)__libc_sigaction(SIGINT, &intact, NULL);
105 (void)__libc_sigaction(SIGQUIT, &quitact, NULL);
106 (void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
107 return (pid == -1 ? -1 : pstat);
108 }
109
110 __weak_reference(__libc_system, __system);
111 __weak_reference(__libc_system, _system);
112