xref: /freebsd/crypto/krb5/src/lib/apputils/daemon.c (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)
1 /* -*- mode: c; c-file-style: "bsd"; indent-tabs-mode: t -*- */
2 /*
3  * Copyright (c) 1990 The Regents of the University of California.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by the University of
17  *	California, Berkeley and its contributors.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "k5-int.h"
36 #include <fcntl.h>
37 #include <sys/types.h>
38 #include <sys/file.h>
39 #include <unistd.h>
40 #ifdef HAVE_PATHS_H
41 #include <paths.h>
42 #endif
43 
44 #ifndef _PATH_DEVNULL
45 #define _PATH_DEVNULL "/dev/null"
46 #endif
47 
48 int
daemon(nochdir,noclose)49 daemon(nochdir, noclose)
50 	int nochdir, noclose;
51 {
52 	int cpid;
53 
54 	if ((cpid = fork()) == -1)
55 		return (-1);
56 	if (cpid)
57 		exit(0);
58 #ifdef HAVE_SETSID
59 	(void) setsid();
60 #else
61 #ifndef TIOCNOTTY
62 	setpgrp();
63 #else
64 	{
65 		int n;
66 
67 		/*
68 		 * The open below may hang on pseudo ttys if the person
69 		 * who starts named logs out before this point.  Thus,
70 		 * the need for the timer.
71 		 */
72 		alarm(120);
73 		n = open("/dev/tty", O_RDWR);
74 		alarm(0);
75 		if (n > 0) {
76 			(void) ioctl(n, TIOCNOTTY, (char *)NULL);
77 			(void) close(n);
78 		}
79 	}
80 #endif
81 #endif
82 	if (!nochdir)
83 		(void) chdir("/");
84 	if (!noclose) {
85 		int devnull = open(_PATH_DEVNULL, O_RDWR, 0);
86 
87 		if (devnull != -1) {
88 			(void) dup2(devnull, 0);
89 			(void) dup2(devnull, 1);
90 			(void) dup2(devnull, 2);
91 			if (devnull > 2)
92 				(void) close(devnull);
93 		}
94 	}
95 	return (0);
96 }
97