1 /* 2 * Copyright (c) 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 2016 The DragonFly Project 5 * Copyright (c) 2014 The FreeBSD Foundation 6 * All rights reserved. 7 * 8 * This code is derived from software written by Ken Arnold and 9 * published in UNIX Review, Vol. 6, No. 8. 10 * 11 * Portions of this software were developed by Edward Tomasz Napierala 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 */ 39 40 #include <sys/types.h> 41 #include <sys/queue.h> 42 #include <sys/wait.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <paths.h> 46 #include <stdarg.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #include "common.h" 53 54 extern char **environ; 55 56 struct pid { 57 SLIST_ENTRY(pid) next; 58 FILE *outfp; 59 pid_t pid; 60 char *command; 61 }; 62 static SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist); 63 64 #define ARGV_LEN 42 65 66 /* 67 * Replacement for popen(3), without stdin (which we do not use), but with 68 * stderr, proper logging, and improved command line arguments passing. 69 * Error handling is built in - if it returns, then it succeeded. 70 */ 71 FILE * 72 auto_popen(const char *argv0, ...) 73 { 74 va_list ap; 75 struct pid *cur, *p; 76 pid_t pid; 77 int error, i, nullfd, outfds[2]; 78 char *arg, *argv[ARGV_LEN], *command; 79 80 nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 81 if (nullfd < 0) 82 log_err(1, "cannot open %s", _PATH_DEVNULL); 83 84 error = pipe(outfds); 85 if (error != 0) 86 log_err(1, "pipe"); 87 88 cur = malloc(sizeof(struct pid)); 89 if (cur == NULL) 90 log_err(1, "malloc"); 91 92 argv[0] = checked_strdup(argv0); 93 command = argv[0]; 94 95 va_start(ap, argv0); 96 for (i = 1;; i++) { 97 if (i >= ARGV_LEN) 98 log_errx(1, "too many arguments to auto_popen"); 99 arg = va_arg(ap, char *); 100 argv[i] = arg; 101 if (arg == NULL) 102 break; 103 104 command = concat(command, ' ', arg); 105 } 106 va_end(ap); 107 108 cur->command = checked_strdup(command); 109 110 switch (pid = fork()) { 111 case -1: /* Error. */ 112 log_err(1, "fork"); 113 /* NOTREACHED */ 114 case 0: /* Child. */ 115 dup2(nullfd, STDIN_FILENO); 116 dup2(outfds[1], STDOUT_FILENO); 117 118 close(nullfd); 119 close(outfds[0]); 120 close(outfds[1]); 121 122 SLIST_FOREACH(p, &pidlist, next) 123 close(fileno(p->outfp)); 124 execvp(argv[0], argv); 125 log_err(1, "failed to execute %s", argv[0]); 126 /* NOTREACHED */ 127 } 128 129 log_debugx("executing \"%s\" as pid %d", command, pid); 130 131 /* Parent; assume fdopen cannot fail. */ 132 cur->outfp = fdopen(outfds[0], "r"); 133 close(nullfd); 134 close(outfds[1]); 135 136 /* Link into list of file descriptors. */ 137 cur->pid = pid; 138 SLIST_INSERT_HEAD(&pidlist, cur, next); 139 140 return (cur->outfp); 141 } 142 143 int 144 auto_pclose(FILE *iop) 145 { 146 struct pid *cur, *last = NULL; 147 int status; 148 pid_t pid; 149 150 /* 151 * Find the appropriate file pointer and remove it from the list. 152 */ 153 SLIST_FOREACH(cur, &pidlist, next) { 154 if (cur->outfp == iop) 155 break; 156 last = cur; 157 } 158 if (cur == NULL) { 159 return (-1); 160 } 161 if (last == NULL) 162 SLIST_REMOVE_HEAD(&pidlist, next); 163 else 164 SLIST_REMOVE_AFTER(last, next); 165 166 fclose(cur->outfp); 167 168 do { 169 pid = wait4(cur->pid, &status, 0, NULL); 170 } while (pid == -1 && errno == EINTR); 171 172 if (WIFSIGNALED(status)) { 173 log_warnx("\"%s\", pid %d, terminated with signal %d", 174 cur->command, pid, WTERMSIG(status)); 175 return (status); 176 } 177 178 if (WEXITSTATUS(status) != 0) { 179 log_warnx("\"%s\", pid %d, terminated with exit status %d", 180 cur->command, pid, WEXITSTATUS(status)); 181 return (status); 182 } 183 184 log_debugx("\"%s\", pid %d, terminated gracefully", cur->command, pid); 185 186 free(cur->command); 187 free(cur); 188 189 return (pid == -1 ? -1 : status); 190 } 191