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 47 system(const char *command) 48 { 49 50 return (((int (*)(const char *)) 51 __libc_interposing[INTERPOS_system])(command)); 52 } 53 54 int 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