1270096Strasz/* 2332597Strasz * SPDX-License-Identifier: BSD-3-Clause 3332597Strasz * 4270096Strasz * Copyright (c) 1988, 1993 5270096Strasz * The Regents of the University of California. All rights reserved. 6270096Strasz * Copyright (c) 2014 The FreeBSD Foundation 7270096Strasz * All rights reserved. 8270096Strasz * 9270096Strasz * This code is derived from software written by Ken Arnold and 10270096Strasz * published in UNIX Review, Vol. 6, No. 8. 11270096Strasz * 12270096Strasz * Portions of this software were developed by Edward Tomasz Napierala 13270096Strasz * under sponsorship from the FreeBSD Foundation. 14270096Strasz * 15270096Strasz * Redistribution and use in source and binary forms, with or without 16270096Strasz * modification, are permitted provided that the following conditions 17270096Strasz * are met: 18270096Strasz * 1. Redistributions of source code must retain the above copyright 19270096Strasz * notice, this list of conditions and the following disclaimer. 20270096Strasz * 2. Redistributions in binary form must reproduce the above copyright 21270096Strasz * notice, this list of conditions and the following disclaimer in the 22270096Strasz * documentation and/or other materials provided with the distribution. 23270096Strasz * 4. Neither the name of the University nor the names of its contributors 24270096Strasz * may be used to endorse or promote products derived from this software 25270096Strasz * without specific prior written permission. 26270096Strasz * 27270096Strasz * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28270096Strasz * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29270096Strasz * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30270096Strasz * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31270096Strasz * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32270096Strasz * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33270096Strasz * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34270096Strasz * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35270096Strasz * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36270096Strasz * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37270096Strasz * SUCH DAMAGE. 38270096Strasz * 39270096Strasz */ 40270096Strasz 41270276Strasz#include <sys/cdefs.h> 42270276Strasz__FBSDID("$FreeBSD: stable/11/usr.sbin/autofs/popen.c 332597 2018-04-16 16:16:24Z trasz $"); 43270276Strasz 44270096Strasz#include <sys/param.h> 45270096Strasz#include <sys/queue.h> 46270096Strasz#include <sys/wait.h> 47270096Strasz 48270096Strasz#include <errno.h> 49270096Strasz#include <fcntl.h> 50270096Strasz#include <unistd.h> 51270096Strasz#include <stdarg.h> 52270096Strasz#include <stdio.h> 53270096Strasz#include <stdlib.h> 54270096Strasz#include <string.h> 55270096Strasz#include <paths.h> 56270096Strasz 57270096Strasz#include "common.h" 58270096Strasz 59270096Straszextern char **environ; 60270096Strasz 61270096Straszstruct pid { 62270096Strasz SLIST_ENTRY(pid) next; 63270096Strasz FILE *outfp; 64270096Strasz pid_t pid; 65270096Strasz char *command; 66270096Strasz}; 67270096Straszstatic SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist); 68270096Strasz 69270096Strasz#define ARGV_LEN 42 70270096Strasz 71270096Strasz/* 72270096Strasz * Replacement for popen(3), without stdin (which we do not use), but with 73270096Strasz * stderr, proper logging, and improved command line arguments passing. 74270096Strasz * Error handling is built in - if it returns, then it succeeded. 75270096Strasz */ 76270096StraszFILE * 77270096Straszauto_popen(const char *argv0, ...) 78270096Strasz{ 79270096Strasz va_list ap; 80270096Strasz struct pid *cur, *p; 81270096Strasz pid_t pid; 82270096Strasz int error, i, nullfd, outfds[2]; 83270096Strasz char *arg, *argv[ARGV_LEN], *command; 84270096Strasz 85270096Strasz nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 86270096Strasz if (nullfd < 0) 87270096Strasz log_err(1, "cannot open %s", _PATH_DEVNULL); 88270096Strasz 89270096Strasz error = pipe(outfds); 90270096Strasz if (error != 0) 91270096Strasz log_err(1, "pipe"); 92270096Strasz 93270096Strasz cur = malloc(sizeof(struct pid)); 94270096Strasz if (cur == NULL) 95270096Strasz log_err(1, "malloc"); 96270096Strasz 97270096Strasz argv[0] = checked_strdup(argv0); 98270096Strasz command = argv[0]; 99270096Strasz 100270096Strasz va_start(ap, argv0); 101270096Strasz for (i = 1;; i++) { 102270096Strasz if (i >= ARGV_LEN) 103270096Strasz log_errx(1, "too many arguments to auto_popen"); 104270096Strasz arg = va_arg(ap, char *); 105270096Strasz argv[i] = arg; 106270096Strasz if (arg == NULL) 107270096Strasz break; 108270096Strasz 109279813Strasz command = concat(command, ' ', arg); 110270096Strasz } 111270096Strasz va_end(ap); 112270096Strasz 113270096Strasz cur->command = checked_strdup(command); 114270096Strasz 115270096Strasz switch (pid = fork()) { 116270096Strasz case -1: /* Error. */ 117270096Strasz log_err(1, "fork"); 118270096Strasz /* NOTREACHED */ 119270096Strasz case 0: /* Child. */ 120270096Strasz dup2(nullfd, STDIN_FILENO); 121270096Strasz dup2(outfds[1], STDOUT_FILENO); 122270096Strasz 123270096Strasz close(nullfd); 124270096Strasz close(outfds[0]); 125270096Strasz close(outfds[1]); 126270096Strasz 127270096Strasz SLIST_FOREACH(p, &pidlist, next) 128270096Strasz close(fileno(p->outfp)); 129270096Strasz execvp(argv[0], argv); 130270096Strasz log_err(1, "failed to execute %s", argv[0]); 131270096Strasz /* NOTREACHED */ 132270096Strasz } 133270096Strasz 134270096Strasz log_debugx("executing \"%s\" as pid %d", command, pid); 135270096Strasz 136270096Strasz /* Parent; assume fdopen cannot fail. */ 137270096Strasz cur->outfp = fdopen(outfds[0], "r"); 138270096Strasz close(nullfd); 139270096Strasz close(outfds[1]); 140270096Strasz 141270096Strasz /* Link into list of file descriptors. */ 142270096Strasz cur->pid = pid; 143270096Strasz SLIST_INSERT_HEAD(&pidlist, cur, next); 144270096Strasz 145270096Strasz return (cur->outfp); 146270096Strasz} 147270096Strasz 148270096Straszint 149270096Straszauto_pclose(FILE *iop) 150270096Strasz{ 151270096Strasz struct pid *cur, *last = NULL; 152270096Strasz int status; 153270096Strasz pid_t pid; 154270096Strasz 155270096Strasz /* 156270096Strasz * Find the appropriate file pointer and remove it from the list. 157270096Strasz */ 158270096Strasz SLIST_FOREACH(cur, &pidlist, next) { 159270096Strasz if (cur->outfp == iop) 160270096Strasz break; 161270096Strasz last = cur; 162270096Strasz } 163270096Strasz if (cur == NULL) { 164270096Strasz return (-1); 165270096Strasz } 166270096Strasz if (last == NULL) 167270096Strasz SLIST_REMOVE_HEAD(&pidlist, next); 168270096Strasz else 169270096Strasz SLIST_REMOVE_AFTER(last, next); 170270096Strasz 171270096Strasz fclose(cur->outfp); 172270096Strasz 173270096Strasz do { 174270096Strasz pid = wait4(cur->pid, &status, 0, NULL); 175270096Strasz } while (pid == -1 && errno == EINTR); 176270096Strasz 177270096Strasz if (WIFSIGNALED(status)) { 178270096Strasz log_warnx("\"%s\", pid %d, terminated with signal %d", 179270096Strasz cur->command, pid, WTERMSIG(status)); 180270096Strasz return (status); 181270096Strasz } 182270096Strasz 183270096Strasz if (WEXITSTATUS(status) != 0) { 184270096Strasz log_warnx("\"%s\", pid %d, terminated with exit status %d", 185270096Strasz cur->command, pid, WEXITSTATUS(status)); 186270096Strasz return (status); 187270096Strasz } 188270096Strasz 189270096Strasz log_debugx("\"%s\", pid %d, terminated gracefully", cur->command, pid); 190270096Strasz 191270096Strasz free(cur->command); 192270096Strasz free(cur); 193270096Strasz 194270096Strasz return (pid == -1 ? -1 : status); 195270096Strasz} 196