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) 2016 The DragonFly Project 7 * Copyright (c) 2014 The FreeBSD Foundation 8 * All rights reserved. 9 * 10 * This code is derived from software written by Ken Arnold and 11 * published in UNIX Review, Vol. 6, No. 8. 12 * 13 * Portions of this software were developed by Edward Tomasz Napierala 14 * under sponsorship from the FreeBSD Foundation. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 */ 41 42 #include <sys/types.h> 43 #include <sys/queue.h> 44 #include <sys/wait.h> 45 #include <errno.h> 46 #include <fcntl.h> 47 #include <paths.h> 48 #include <stdarg.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include "common.h" 55 56 extern char **environ; 57 58 struct pid { 59 SLIST_ENTRY(pid) next; 60 FILE *outfp; 61 pid_t pid; 62 char *command; 63 }; 64 static SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist); 65 66 #define ARGV_LEN 42 67 68 /* 69 * Replacement for popen(3), without stdin (which we do not use), but with 70 * stderr, proper logging, and improved command line arguments passing. 71 * Error handling is built in - if it returns, then it succeeded. 72 */ 73 FILE * 74 auto_popen(const char *argv0, ...) 75 { 76 va_list ap; 77 struct pid *cur, *p; 78 pid_t pid; 79 int error, i, nullfd, outfds[2]; 80 char *arg, *argv[ARGV_LEN], *command; 81 82 nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 83 if (nullfd < 0) 84 log_err(1, "cannot open %s", _PATH_DEVNULL); 85 86 error = pipe(outfds); 87 if (error != 0) 88 log_err(1, "pipe"); 89 90 cur = malloc(sizeof(struct pid)); 91 if (cur == NULL) 92 log_err(1, "malloc"); 93 94 argv[0] = checked_strdup(argv0); 95 command = argv[0]; 96 97 va_start(ap, argv0); 98 for (i = 1;; i++) { 99 if (i >= ARGV_LEN) 100 log_errx(1, "too many arguments to auto_popen"); 101 arg = va_arg(ap, char *); 102 argv[i] = arg; 103 if (arg == NULL) 104 break; 105 106 command = concat(command, ' ', arg); 107 } 108 va_end(ap); 109 110 cur->command = checked_strdup(command); 111 112 switch (pid = fork()) { 113 case -1: /* Error. */ 114 log_err(1, "fork"); 115 /* NOTREACHED */ 116 case 0: /* Child. */ 117 dup2(nullfd, STDIN_FILENO); 118 dup2(outfds[1], STDOUT_FILENO); 119 120 close(nullfd); 121 close(outfds[0]); 122 close(outfds[1]); 123 124 SLIST_FOREACH(p, &pidlist, next) 125 close(fileno(p->outfp)); 126 execvp(argv[0], argv); 127 log_err(1, "failed to execute %s", argv[0]); 128 /* NOTREACHED */ 129 } 130 131 log_debugx("executing \"%s\" as pid %d", command, pid); 132 133 /* Parent; assume fdopen cannot fail. */ 134 cur->outfp = fdopen(outfds[0], "r"); 135 close(nullfd); 136 close(outfds[1]); 137 138 /* Link into list of file descriptors. */ 139 cur->pid = pid; 140 SLIST_INSERT_HEAD(&pidlist, cur, next); 141 142 return (cur->outfp); 143 } 144 145 int 146 auto_pclose(FILE *iop) 147 { 148 struct pid *cur, *last = NULL; 149 int status; 150 pid_t pid; 151 152 /* 153 * Find the appropriate file pointer and remove it from the list. 154 */ 155 SLIST_FOREACH(cur, &pidlist, next) { 156 if (cur->outfp == iop) 157 break; 158 last = cur; 159 } 160 if (cur == NULL) { 161 return (-1); 162 } 163 if (last == NULL) 164 SLIST_REMOVE_HEAD(&pidlist, next); 165 else 166 SLIST_REMOVE_AFTER(last, next); 167 168 fclose(cur->outfp); 169 170 do { 171 pid = wait4(cur->pid, &status, 0, NULL); 172 } while (pid == -1 && errno == EINTR); 173 174 if (WIFSIGNALED(status)) { 175 log_warnx("\"%s\", pid %d, terminated with signal %d", 176 cur->command, pid, WTERMSIG(status)); 177 return (status); 178 } 179 180 if (WEXITSTATUS(status) != 0) { 181 log_warnx("\"%s\", pid %d, terminated with exit status %d", 182 cur->command, pid, WEXITSTATUS(status)); 183 return (status); 184 } 185 186 log_debugx("\"%s\", pid %d, terminated gracefully", cur->command, pid); 187 188 free(cur->command); 189 free(cur); 190 191 return (pid == -1 ? -1 : status); 192 } 193