daemon.c revision 159d09a20817016f09b3ea28d1bdada4a336bb91
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "k5-int.h"
#include <fcntl.h>
#include <sys/types.h>
#include <sys/file.h>
#include <unistd.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif
#ifndef _PATH_DEVNULL
#define _PATH_DEVNULL "/dev/null"
#endif
int
daemon(nochdir, noclose)
int nochdir, noclose;
{
int cpid;
if ((cpid = fork()) == -1)
return (-1);
if (cpid)
exit(0);
#ifdef HAVE_SETSID
(void) setsid();
#else
#ifndef TIOCNOTTY
setpgrp();
#else
{
int n;
/*
* The open below may hang on pseudo ttys if the person
* who starts named logs out before this point. Thus,
* the need for the timer.
*/
alarm(120);
n = open("/dev/tty", O_RDWR);
alarm(0);
if (n > 0) {
(void) ioctl(n, TIOCNOTTY, (char *)NULL);
(void) close(n);
}
}
#endif
#endif
if (!nochdir)
(void) chdir("/");
if (!noclose) {
int devnull = open(_PATH_DEVNULL, O_RDWR, 0);
if (devnull != -1) {
(void) dup2(devnull, 0);
(void) dup2(devnull, 1);
(void) dup2(devnull, 2);
if (devnull > 2)
(void) close(devnull);
}
}
return (0);
}