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 #include "namespace.h"
33 #include <sys/types.h>
34 #include <sys/wait.h>
35 #include <signal.h>
36 #include <stdlib.h>
37 #include <stddef.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <paths.h>
41 #include <errno.h>
42 #include "un-namespace.h"
43 #include "libc_private.h"
44
45 #pragma weak system
46 int
system(const char * command)47 system(const char *command)
48 {
49
50 return (((int (*)(const char *))
51 __libc_interposing[INTERPOS_system])(command));
52 }
53
54 int
__libc_system(const char * command)55 __libc_system(const char *command)
56 {
57 pid_t pid, savedpid;
58 int pstat;
59 struct sigaction ign, intact, quitact;
60 sigset_t newsigblock, oldsigblock;
61
62 if (!command) /* just checking... */
63 return(1);
64
65 (void)sigemptyset(&newsigblock);
66 (void)sigaddset(&newsigblock, SIGCHLD);
67 (void)sigaddset(&newsigblock, SIGINT);
68 (void)sigaddset(&newsigblock, SIGQUIT);
69 (void)__libc_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
70 switch(pid = vfork()) {
71 /*
72 * In the child, use unwrapped syscalls. libthr is in
73 * undefined state after vfork().
74 */
75 case -1: /* error */
76 (void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
77 return (-1);
78 case 0: /* child */
79 /*
80 * Restore original signal dispositions and exec the command.
81 */
82 (void)__sys_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
83 execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
84 _exit(127);
85 }
86 /*
87 * If we are running means that the child has either completed
88 * its execve, or has failed.
89 * Block SIGINT/QUIT because sh -c handles it and wait for
90 * it to clean up.
91 */
92 memset(&ign, 0, sizeof(ign));
93 ign.sa_handler = SIG_IGN;
94 (void)sigemptyset(&ign.sa_mask);
95 (void)__libc_sigaction(SIGINT, &ign, &intact);
96 (void)__libc_sigaction(SIGQUIT, &ign, &quitact);
97 savedpid = pid;
98 do {
99 pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
100 } while (pid == -1 && errno == EINTR);
101 (void)__libc_sigaction(SIGINT, &intact, NULL);
102 (void)__libc_sigaction(SIGQUIT, &quitact, NULL);
103 (void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
104 return (pid == -1 ? -1 : pstat);
105 }
106
107 __weak_reference(__libc_system, __system);
108 __weak_reference(__libc_system, _system);
109