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 * Copyright (c) 2014 The FreeBSD Foundation 7 * All rights reserved. 8 * 9 * This code is derived from software written by Ken Arnold and 10 * published in UNIX Review, Vol. 6, No. 8. 11 * 12 * Portions of this software were developed by Edward Tomasz Napierala 13 * under sponsorship from the FreeBSD Foundation. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 3. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 */ 40 41 #include <sys/cdefs.h> 42 #include <sys/param.h> 43 #include <sys/queue.h> 44 #include <sys/wait.h> 45 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <unistd.h> 49 #include <stdarg.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <paths.h> 54 55 #include "common.h" 56 57 extern char **environ; 58 59 struct pid { 60 SLIST_ENTRY(pid) next; 61 FILE *outfp; 62 pid_t pid; 63 char *command; 64 }; 65 static SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist); 66 67 #define ARGV_LEN 42 68 69 /* 70 * Replacement for popen(3), without stdin (which we do not use), but with 71 * stderr, proper logging, and improved command line arguments passing. 72 * Error handling is built in - if it returns, then it succeeded. 73 */ 74 FILE * 75 auto_popen(const char *argv0, ...) 76 { 77 va_list ap; 78 struct pid *cur, *p; 79 pid_t pid; 80 int error, i, nullfd, outfds[2]; 81 char *arg, *argv[ARGV_LEN], *command; 82 83 nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 84 if (nullfd < 0) 85 log_err(1, "cannot open %s", _PATH_DEVNULL); 86 87 error = pipe(outfds); 88 if (error != 0) 89 log_err(1, "pipe"); 90 91 cur = malloc(sizeof(struct pid)); 92 if (cur == NULL) 93 log_err(1, "malloc"); 94 95 argv[0] = checked_strdup(argv0); 96 command = argv[0]; 97 98 va_start(ap, argv0); 99 for (i = 1;; i++) { 100 if (i >= ARGV_LEN) 101 log_errx(1, "too many arguments to auto_popen"); 102 arg = va_arg(ap, char *); 103 argv[i] = arg; 104 if (arg == NULL) 105 break; 106 107 command = concat(command, ' ', arg); 108 } 109 va_end(ap); 110 111 cur->command = checked_strdup(command); 112 113 switch (pid = fork()) { 114 case -1: /* Error. */ 115 log_err(1, "fork"); 116 /* NOTREACHED */ 117 case 0: /* Child. */ 118 dup2(nullfd, STDIN_FILENO); 119 dup2(outfds[1], STDOUT_FILENO); 120 121 close(nullfd); 122 close(outfds[0]); 123 close(outfds[1]); 124 125 SLIST_FOREACH(p, &pidlist, next) 126 close(fileno(p->outfp)); 127 execvp(argv[0], argv); 128 log_err(1, "failed to execute %s", argv[0]); 129 /* NOTREACHED */ 130 } 131 132 log_debugx("executing \"%s\" as pid %d", command, pid); 133 134 /* Parent; assume fdopen cannot fail. */ 135 cur->outfp = fdopen(outfds[0], "r"); 136 close(nullfd); 137 close(outfds[1]); 138 139 /* Link into list of file descriptors. */ 140 cur->pid = pid; 141 SLIST_INSERT_HEAD(&pidlist, cur, next); 142 143 return (cur->outfp); 144 } 145 146 int 147 auto_pclose(FILE *iop) 148 { 149 struct pid *cur, *last = NULL; 150 int status; 151 pid_t pid; 152 153 /* 154 * Find the appropriate file pointer and remove it from the list. 155 */ 156 SLIST_FOREACH(cur, &pidlist, next) { 157 if (cur->outfp == iop) 158 break; 159 last = cur; 160 } 161 if (cur == NULL) { 162 return (-1); 163 } 164 if (last == NULL) 165 SLIST_REMOVE_HEAD(&pidlist, next); 166 else 167 SLIST_REMOVE_AFTER(last, next); 168 169 fclose(cur->outfp); 170 171 do { 172 pid = wait4(cur->pid, &status, 0, NULL); 173 } while (pid == -1 && errno == EINTR); 174 175 if (WIFSIGNALED(status)) { 176 log_warnx("\"%s\", pid %d, terminated with signal %d", 177 cur->command, pid, WTERMSIG(status)); 178 return (status); 179 } 180 181 if (WEXITSTATUS(status) != 0) { 182 log_warnx("\"%s\", pid %d, terminated with exit status %d", 183 cur->command, pid, WEXITSTATUS(status)); 184 return (status); 185 } 186 187 log_debugx("\"%s\", pid %d, terminated gracefully", cur->command, pid); 188 189 free(cur->command); 190 free(cur); 191 192 return (pid == -1 ? -1 : status); 193 } 194