1 /* $OpenBSD: popen.c,v 1.30 2015/11/15 23:24:24 millert Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software written by Ken Arnold and 8 * published in UNIX Review, Vol. 6, No. 8. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 */ 35 36 /* this came out of the ftpd sources; it's been modified to avoid the 37 * globbing stuff since we don't need it. also execvp instead of execv. 38 */ 39 40 #include <sys/types.h> 41 #include <sys/wait.h> 42 43 #include <bitstring.h> /* for structs.h */ 44 #include <err.h> 45 #include <errno.h> 46 #include <login_cap.h> 47 #include <pwd.h> 48 #include <signal.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <syslog.h> 53 #include <unistd.h> 54 #include <time.h> /* for structs.h */ 55 56 #include "macros.h" 57 #include "structs.h" 58 #include "funcs.h" 59 60 #define MAX_ARGV 100 61 #define MAX_GARGV 1000 62 63 /* 64 * Special version of popen which avoids call to shell 65 */ 66 FILE * 67 cron_popen(char *program, char *type, struct passwd *pw, pid_t *pidptr) 68 { 69 char *cp; 70 FILE *iop; 71 int argc, pdes[2]; 72 pid_t pid; 73 char *argv[MAX_ARGV]; 74 75 if ((*type != 'r' && *type != 'w') || type[1] != '\0') 76 return (NULL); 77 78 if (pipe(pdes) < 0) 79 return (NULL); 80 81 /* break up string into pieces */ 82 for (argc = 0, cp = program; argc < MAX_ARGV - 1; cp = NULL) 83 if (!(argv[argc++] = strtok(cp, " \t\n"))) 84 break; 85 argv[MAX_ARGV-1] = NULL; 86 87 switch (pid = fork()) { 88 case -1: /* error */ 89 (void)close(pdes[0]); 90 (void)close(pdes[1]); 91 return (NULL); 92 /* NOTREACHED */ 93 case 0: /* child */ 94 if (pw) { 95 if (setusercontext(0, pw, pw->pw_uid, LOGIN_SETALL) < 0) { 96 syslog(LOG_ERR, 97 "(%s) SETUSERCONTEXT FAILED (%m)", 98 pw->pw_name); 99 warn("setusercontext failed for %s", 100 pw->pw_name); 101 _exit(EXIT_FAILURE); 102 } 103 } 104 if (*type == 'r') { 105 if (pdes[1] != STDOUT_FILENO) { 106 dup2(pdes[1], STDOUT_FILENO); 107 (void)close(pdes[1]); 108 } 109 dup2(STDOUT_FILENO, STDERR_FILENO); 110 (void)close(pdes[0]); 111 } else { 112 if (pdes[0] != STDIN_FILENO) { 113 dup2(pdes[0], STDIN_FILENO); 114 (void)close(pdes[0]); 115 } 116 (void)close(pdes[1]); 117 } 118 execvp(argv[0], argv); 119 _exit(1); 120 } 121 122 /* parent; assume fdopen can't fail... */ 123 if (*type == 'r') { 124 iop = fdopen(pdes[0], type); 125 (void)close(pdes[1]); 126 } else { 127 iop = fdopen(pdes[1], type); 128 (void)close(pdes[0]); 129 } 130 *pidptr = pid; 131 132 return (iop); 133 } 134 135 int 136 cron_pclose(FILE *iop, pid_t pid) 137 { 138 int rv; 139 int status; 140 sigset_t sigset, osigset; 141 142 (void)fclose(iop); 143 sigemptyset(&sigset); 144 sigaddset(&sigset, SIGINT); 145 sigaddset(&sigset, SIGQUIT); 146 sigaddset(&sigset, SIGHUP); 147 sigprocmask(SIG_BLOCK, &sigset, &osigset); 148 while ((rv = waitpid(pid, &status, 0)) < 0 && errno == EINTR) 149 continue; 150 sigprocmask(SIG_SETMASK, &osigset, NULL); 151 if (rv < 0) 152 return (rv); 153 if (WIFEXITED(status)) 154 return (WEXITSTATUS(status)); 155 return (1); 156 } 157