/* 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> #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 && (fd = open(_PATH_DEVNULL, O_RDWR)) != -1) { dup2(fd, STDIN_FILENO); dup2(fd, STDOUT_FILENO); dup2(fd, STDERR_FILENO); if (fd > 2) close(fd); } return 0; } #endif