1 /* 2 * Copyright (c) 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 2014 The FreeBSD Foundation 5 * 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 * Portions of this software were developed by Edward Tomasz Napierala 11 * under sponsorship from the FreeBSD Foundation. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * $FreeBSD$ 38 */ 39 40 #include <sys/param.h> 41 #include <sys/queue.h> 42 #include <sys/wait.h> 43 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <unistd.h> 47 #include <stdarg.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <paths.h> 52 53 #include "common.h" 54 55 extern char **environ; 56 57 struct pid { 58 SLIST_ENTRY(pid) next; 59 FILE *outfp; 60 pid_t pid; 61 char *command; 62 }; 63 static SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist); 64 65 #define ARGV_LEN 42 66 67 /* 68 * Replacement for popen(3), without stdin (which we do not use), but with 69 * stderr, proper logging, and improved command line arguments passing. 70 * Error handling is built in - if it returns, then it succeeded. 71 */ 72 FILE * 73 auto_popen(const char *argv0, ...) 74 { 75 va_list ap; 76 struct pid *cur, *p; 77 pid_t pid; 78 int error, i, nullfd, outfds[2]; 79 char *arg, *argv[ARGV_LEN], *command; 80 81 nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 82 if (nullfd < 0) 83 log_err(1, "cannot open %s", _PATH_DEVNULL); 84 85 error = pipe(outfds); 86 if (error != 0) 87 log_err(1, "pipe"); 88 89 cur = malloc(sizeof(struct pid)); 90 if (cur == NULL) 91 log_err(1, "malloc"); 92 93 argv[0] = checked_strdup(argv0); 94 command = argv[0]; 95 96 va_start(ap, argv0); 97 for (i = 1;; i++) { 98 if (i >= ARGV_LEN) 99 log_errx(1, "too many arguments to auto_popen"); 100 arg = va_arg(ap, char *); 101 argv[i] = arg; 102 if (arg == NULL) 103 break; 104 105 command = separated_concat(command, arg, ' '); 106 } 107 va_end(ap); 108 109 cur->command = checked_strdup(command); 110 111 switch (pid = fork()) { 112 case -1: /* Error. */ 113 log_err(1, "fork"); 114 /* NOTREACHED */ 115 case 0: /* Child. */ 116 dup2(nullfd, STDIN_FILENO); 117 dup2(outfds[1], STDOUT_FILENO); 118 119 close(nullfd); 120 close(outfds[0]); 121 close(outfds[1]); 122 123 SLIST_FOREACH(p, &pidlist, next) 124 close(fileno(p->outfp)); 125 execvp(argv[0], argv); 126 log_err(1, "failed to execute %s", argv[0]); 127 /* NOTREACHED */ 128 } 129 130 log_debugx("executing \"%s\" as pid %d", command, pid); 131 132 /* Parent; assume fdopen cannot fail. */ 133 cur->outfp = fdopen(outfds[0], "r"); 134 close(nullfd); 135 close(outfds[1]); 136 137 /* Link into list of file descriptors. */ 138 cur->pid = pid; 139 SLIST_INSERT_HEAD(&pidlist, cur, next); 140 141 return (cur->outfp); 142 } 143 144 int 145 auto_pclose(FILE *iop) 146 { 147 struct pid *cur, *last = NULL; 148 int status; 149 pid_t pid; 150 151 /* 152 * Find the appropriate file pointer and remove it from the list. 153 */ 154 SLIST_FOREACH(cur, &pidlist, next) { 155 if (cur->outfp == iop) 156 break; 157 last = cur; 158 } 159 if (cur == NULL) { 160 return (-1); 161 } 162 if (last == NULL) 163 SLIST_REMOVE_HEAD(&pidlist, next); 164 else 165 SLIST_REMOVE_AFTER(last, next); 166 167 fclose(cur->outfp); 168 169 do { 170 pid = wait4(cur->pid, &status, 0, NULL); 171 } while (pid == -1 && errno == EINTR); 172 173 if (WIFSIGNALED(status)) { 174 log_warnx("\"%s\", pid %d, terminated with signal %d", 175 cur->command, pid, WTERMSIG(status)); 176 return (status); 177 } 178 179 if (WEXITSTATUS(status) != 0) { 180 log_warnx("\"%s\", pid %d, terminated with exit status %d", 181 cur->command, pid, WEXITSTATUS(status)); 182 return (status); 183 } 184 185 log_debugx("\"%s\", pid %d, terminated gracefully", cur->command, pid); 186 187 free(cur->command); 188 free(cur); 189 190 return (pid == -1 ? -1 : status); 191 } 192