1 /* $OpenBSD: system.c,v 1.13 2022/05/21 00:53:53 millert Exp $ */ 2 /* 3 * Copyright (c) 1988 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 #include <sys/wait.h> 33 #include <errno.h> 34 #include <signal.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 #include <paths.h> 39 40 int 41 system(const char *command) 42 { 43 pid_t pid, cpid; 44 struct sigaction intsave, quitsave, sa; 45 sigset_t mask, omask; 46 int pstat; 47 char *argp[] = {"sh", "-c", NULL, NULL}; 48 49 if (!command) /* just checking... */ 50 return(1); 51 52 argp[2] = (char *)command; 53 54 sigemptyset(&mask); 55 sigaddset(&mask, SIGCHLD); 56 sigaddset(&mask, SIGINT); 57 sigaddset(&mask, SIGQUIT); 58 sigprocmask(SIG_BLOCK, &mask, &omask); 59 switch (cpid = vfork()) { 60 case -1: /* error */ 61 sigprocmask(SIG_SETMASK, &omask, NULL); 62 return(-1); 63 case 0: /* child */ 64 sigprocmask(SIG_SETMASK, &omask, NULL); 65 execve(_PATH_BSHELL, argp, environ); 66 _exit(127); 67 } 68 69 /* Ignore SIGINT and SIGQUIT while waiting for command to complete. */ 70 memset(&sa, 0, sizeof(sa)); 71 sigemptyset(&sa.sa_mask); 72 sa.sa_handler = SIG_IGN; 73 sigaction(SIGINT, &sa, &intsave); 74 sigaction(SIGQUIT, &sa, &quitsave); 75 sigemptyset(&mask); 76 sigaddset(&mask, SIGINT); 77 sigaddset(&mask, SIGQUIT); 78 sigprocmask(SIG_UNBLOCK, &mask, NULL); 79 80 do { 81 pid = waitpid(cpid, &pstat, 0); 82 } while (pid == -1 && errno == EINTR); 83 84 sigprocmask(SIG_SETMASK, &omask, NULL); 85 sigaction(SIGINT, &intsave, NULL); 86 sigaction(SIGQUIT, &quitsave, NULL); 87 return (pid == -1 ? -1 : pstat); 88 } 89 DEF_STRONG(system); 90