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 <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 52 int 53 system(const char *command) 54 { 55 56 return (((int (*)(const char *)) 57 __libc_interposing[INTERPOS_system])(command)); 58 } 59 60 int 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