1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2013 The FreeBSD Foundation 5 * Copyright (c) 2015 Mariusz Zaborski <oshogbo@FreeBSD.org> 6 * All rights reserved. 7 * 8 * This software was developed by Pawel Jakub Dawidek under sponsorship from 9 * the FreeBSD Foundation. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $FreeBSD$ 33 */ 34 35 #include <err.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <paths.h> 39 #include <stdlib.h> 40 41 #include "libcasper_impl.h" 42 43 bool 44 fd_is_valid(int fd) 45 { 46 47 return (fcntl(fd, F_GETFL) != -1 || errno != EBADF); 48 } 49 50 void 51 fd_fix_environment(int *fdp) 52 { 53 int nullfd, nfd; 54 55 if (*fdp > STDERR_FILENO) 56 return; 57 58 nullfd = open(_PATH_DEVNULL, O_RDWR); 59 if (nullfd == -1) 60 errx(1, "Unable to open %s", _PATH_DEVNULL); 61 62 while (*fdp <= STDERR_FILENO) { 63 nfd = dup(*fdp); 64 if (nfd == -1) 65 errx(1, "Unable to secure fd"); 66 if (dup2(nullfd, *fdp) == -1) 67 errx(1, "Unable to secure fd"); 68 *fdp = nfd; 69 } 70 71 close(nullfd); 72 } 73 74