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 50 system(const char *command) 51 { 52 53 return (((int (*)(const char *)) 54 __libc_interposing[INTERPOS_system])(command)); 55 } 56 57 int 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