1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)daemon.c 8.1 (Berkeley) 6/4/93 30 * $FreeBSD: src/lib/libc/gen/daemon.c,v 1.8 2007/01/09 00:27:53 imp Exp $ 31 * $DragonFly: src/lib/libc/gen/daemon.c,v 1.4 2005/04/26 15:57:39 joerg Exp $ 32 */ 33 34 #include "namespace.h" 35 #include <errno.h> 36 #include <fcntl.h> 37 #include <paths.h> 38 #include <stdlib.h> 39 #include <signal.h> 40 #include <unistd.h> 41 #include "un-namespace.h" 42 43 int 44 daemon(int nochdir, int noclose) 45 { 46 struct sigaction osa, sa; 47 int fd; 48 pid_t newgrp; 49 int oerrno; 50 int osa_ok; 51 52 /* A SIGHUP may be thrown when the parent exits below. */ 53 sigemptyset(&sa.sa_mask); 54 sa.sa_handler = SIG_IGN; 55 sa.sa_flags = 0; 56 osa_ok = _sigaction(SIGHUP, &sa, &osa); 57 58 switch (fork()) { 59 case -1: 60 return (-1); 61 case 0: 62 break; 63 default: 64 _exit(0); 65 } 66 67 newgrp = setsid(); 68 oerrno = errno; 69 if (osa_ok != -1) 70 _sigaction(SIGHUP, &osa, NULL); 71 72 if (newgrp == -1) { 73 errno = oerrno; 74 return (-1); 75 } 76 77 if (!nochdir) 78 chdir("/"); 79 80 if (!noclose && (fd = _open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 81 _dup2(fd, STDIN_FILENO); 82 _dup2(fd, STDOUT_FILENO); 83 _dup2(fd, STDERR_FILENO); 84 if (fd > 2) 85 _close(fd); 86 } 87 return (0); 88 } 89