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 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/queue.h> 46 #include <sys/wait.h> 47 48 #include <errno.h> 49 #include <fcntl.h> 50 #include <unistd.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <paths.h> 56 57 #include "common.h" 58 59 extern char **environ; 60 61 struct pid { 62 SLIST_ENTRY(pid) next; 63 FILE *outfp; 64 pid_t pid; 65 char *command; 66 }; 67 static SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist); 68 69 #define ARGV_LEN 42 70 71 /* 72 * Replacement for popen(3), without stdin (which we do not use), but with 73 * stderr, proper logging, and improved command line arguments passing. 74 * Error handling is built in - if it returns, then it succeeded. 75 */ 76 FILE * 77 auto_popen(const char *argv0, ...) 78 { 79 va_list ap; 80 struct pid *cur, *p; 81 pid_t pid; 82 int error, i, nullfd, outfds[2]; 83 char *arg, *argv[ARGV_LEN], *command; 84 85 nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 86 if (nullfd < 0) 87 log_err(1, "cannot open %s", _PATH_DEVNULL); 88 89 error = pipe(outfds); 90 if (error != 0) 91 log_err(1, "pipe"); 92 93 cur = malloc(sizeof(struct pid)); 94 if (cur == NULL) 95 log_err(1, "malloc"); 96 97 argv[0] = checked_strdup(argv0); 98 command = argv[0]; 99 100 va_start(ap, argv0); 101 for (i = 1;; i++) { 102 if (i >= ARGV_LEN) 103 log_errx(1, "too many arguments to auto_popen"); 104 arg = va_arg(ap, char *); 105 argv[i] = arg; 106 if (arg == NULL) 107 break; 108 109 command = concat(command, ' ', arg); 110 } 111 va_end(ap); 112 113 cur->command = checked_strdup(command); 114 115 switch (pid = fork()) { 116 case -1: /* Error. */ 117 log_err(1, "fork"); 118 /* NOTREACHED */ 119 case 0: /* Child. */ 120 dup2(nullfd, STDIN_FILENO); 121 dup2(outfds[1], STDOUT_FILENO); 122 123 close(nullfd); 124 close(outfds[0]); 125 close(outfds[1]); 126 127 SLIST_FOREACH(p, &pidlist, next) 128 close(fileno(p->outfp)); 129 execvp(argv[0], argv); 130 log_err(1, "failed to execute %s", argv[0]); 131 /* NOTREACHED */ 132 } 133 134 log_debugx("executing \"%s\" as pid %d", command, pid); 135 136 /* Parent; assume fdopen cannot fail. */ 137 cur->outfp = fdopen(outfds[0], "r"); 138 close(nullfd); 139 close(outfds[1]); 140 141 /* Link into list of file descriptors. */ 142 cur->pid = pid; 143 SLIST_INSERT_HEAD(&pidlist, cur, next); 144 145 return (cur->outfp); 146 } 147 148 int 149 auto_pclose(FILE *iop) 150 { 151 struct pid *cur, *last = NULL; 152 int status; 153 pid_t pid; 154 155 /* 156 * Find the appropriate file pointer and remove it from the list. 157 */ 158 SLIST_FOREACH(cur, &pidlist, next) { 159 if (cur->outfp == iop) 160 break; 161 last = cur; 162 } 163 if (cur == NULL) { 164 return (-1); 165 } 166 if (last == NULL) 167 SLIST_REMOVE_HEAD(&pidlist, next); 168 else 169 SLIST_REMOVE_AFTER(last, next); 170 171 fclose(cur->outfp); 172 173 do { 174 pid = wait4(cur->pid, &status, 0, NULL); 175 } while (pid == -1 && errno == EINTR); 176 177 if (WIFSIGNALED(status)) { 178 log_warnx("\"%s\", pid %d, terminated with signal %d", 179 cur->command, pid, WTERMSIG(status)); 180 return (status); 181 } 182 183 if (WEXITSTATUS(status) != 0) { 184 log_warnx("\"%s\", pid %d, terminated with exit status %d", 185 cur->command, pid, WEXITSTATUS(status)); 186 return (status); 187 } 188 189 log_debugx("\"%s\", pid %d, terminated gracefully", cur->command, pid); 190 191 free(cur->command); 192 free(cur); 193 194 return (pid == -1 ? -1 : status); 195 } 196