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/* vi: set sw=4 ts=4: */
/* daemon implementation for uClibc
*
* Copyright (c) 1990, 1993
* 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. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
* ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
*
* 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.
*/
/*
* Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
*
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
* Modified for uClibc by Erik Andersen <andersen@uclibc.org>
*/
#include <stdio.h>
#include <features.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <unistd.h>
#include <not-cancel.h>
#include <errno.h>
#ifdef __UCLIBC_HAS_THREADS_NATIVE__
#include <sys/stat.h>
#endif
#ifdef __UCLIBC_HAS_LFS__
#define STAT stat64
#define FSTAT fstat64
#else
#define STAT stat
#define FSTAT fstat
#endif
#if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
#ifndef __ARCH_USE_MMU__
#include <sys/syscall.h>
#include <sched.h>
/* use clone() to get fork() like behavior here -- we just want to disassociate
* from the controlling terminal
*/
static inline attribute_optimize("O3")
pid_t _fork_parent(void)
{
INTERNAL_SYSCALL_DECL(err);
register long ret = INTERNAL_SYSCALL(clone, err, 2, CLONE_VM, 0);
if (ret > 0)
/* parent needs to die now w/out touching stack */
INTERNAL_SYSCALL(exit, err, 1, 0);
return ret;
}
static inline pid_t fork_parent(void)
{
/* Block all signals to keep the parent from using the stack */
pid_t ret;
sigset_t new_set, old_set;
sigfillset(&new_set);
sigprocmask(SIG_BLOCK, &new_set, &old_set);
ret = _fork_parent();
sigprocmask(SIG_SETMASK, &old_set, NULL);
return ret;
}
#else
static inline pid_t fork_parent(void)
{
switch (fork()) {
case -1: return -1;
case 0: return 0;
default: _exit(0);
}
}
#endif
int daemon(int nochdir, int noclose)
{
int fd;
if (fork_parent() == -1)
return -1;
if (setsid() == -1)
return -1;
if (!nochdir)
chdir("/");
if (!noclose)
{
struct STAT st;
if ((fd = open_not_cancel_2(_PATH_DEVNULL, O_RDWR)) != -1
&& (__builtin_expect (FSTAT (fd, &st), 0) == 0))
{
if (__builtin_expect (S_ISCHR (st.st_mode), 1) != 0) {
dup2(fd, STDIN_FILENO);
dup2(fd, STDOUT_FILENO);
dup2(fd, STDERR_FILENO);
if (fd > 2)
close(fd);
} else {
/* We must set an errno value since no
function call actually failed. */
close_not_cancel_no_status (fd);
__set_errno (ENODEV);
return -1;
}
} else {
close_not_cancel_no_status (fd);
return -1;
}
}
return 0;
}
#endif
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