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/* Utility functions to setup applications */
/*
* (C) 2010 by Harald Welte <laforge@gnumonks.org>
* (C) 2011 by Holger Hans Peter Freyther
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
/*! \file application.c
* Routines for helping with the osmocom application setup.
*/
/*! \mainpage libosmocore Documentation
* \section sec_intro Introduction
* This library is a collection of common code used in various
* sub-projects inside the Osmocom family of projects. It includes a
* logging framework, select() loop abstraction, timers with callbacks,
* bit vectors, bit packing/unpacking, convolutional decoding, GSMTAP, a
* generic plugin interface, statistics counters, memory allocator,
* socket abstraction, message buffers, etc.
* \n\n
* libosmocodec is developed as part of the Osmocom (Open Source Mobile
* Communications) project, a community-based, collaborative development
* project to create Free and Open Source implementations of mobile
* communications systems. For more information about Osmocom, please
* see https://osmocom.org/
*
* Please note that C language projects inside Osmocom are typically
* single-threaded event-loop state machine designs. As such,
* routines in libosmocore are not thread-safe. If you must use them in
* a multi-threaded context, you have to add your own locking.
*
* \section sec_copyright Copyright and License
* Copyright © 2008-2016 - Harald Welte, Holger Freyther and contributors\n
* All rights reserved. \n\n
* The source code of libosmocore is licensed under the terms of the GNU
* General Public License as published by the Free Software Foundation;
* either version 2 of the License, or (at your option) any later
* version.\n
* See <http://www.gnu.org/licenses/> or COPYING included in the source
* code package istelf.\n
* The information detailed here is provided AS IS with NO WARRANTY OF
* ANY KIND, INCLUDING THE WARRANTY OF DESIGN, MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE.
* \n\n
*
* \section sec_tracker Homepage + Issue Tracker
* The libosmocore project home page can be found at
* https://osmocom.org/projects/libosmocore
*
* An Issue Tracker can be found at
* https://osmocom.org/projects/libosmocore/issues
*
* \section sec_contact Contact and Support
* Community-based support is available at the OpenBSC mailing list
* <http://lists.osmocom.org/mailman/listinfo/openbsc>\n
* Commercial support options available upon request from
* <http://sysmocom.de/>
*/
#include <osmocom/core/application.h>
#include <osmocom/core/logging.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
struct log_target *osmo_stderr_target;
static void sighup_hdlr(int signal)
{
log_targets_reopen();
}
/*! Ignore \ref SIGPIPE, \ref SIGALRM, \ref SIGHUP and \ref SIGIO */
void osmo_init_ignore_signals(void)
{
/* Signals that by default would terminate */
#ifdef SIGPIPE
signal(SIGPIPE, SIG_IGN);
#endif
signal(SIGALRM, SIG_IGN);
#ifdef SIGHUP
signal(SIGHUP, &sighup_hdlr);
#endif
#ifdef SIGIO
signal(SIGIO, SIG_IGN);
#endif
}
/*! Initialize the osmocom logging framework
* \param[in] log_info Array of available logging sub-systems
* \returns 0 on success, -1 in case of error
*
* This function initializes the osmocom logging systems. It also
* creates the default (stderr) logging target.
*/
int osmo_init_logging(const struct log_info *log_info)
{
log_init(log_info, NULL);
osmo_stderr_target = log_target_create_stderr();
if (!osmo_stderr_target)
return -1;
log_add_target(osmo_stderr_target);
log_set_all_filter(osmo_stderr_target, 1);
return 0;
}
/*! Turn the current process into a background daemon
*
* This function will fork the process, exit the parent and set umask,
* create a new session, close stdin/stdout/stderr and chdir to /tmp
*/
int osmo_daemonize(void)
{
int rc;
pid_t pid, sid;
/* Check if parent PID == init, in which case we are already a daemon */
if (getppid() == 1)
return 0;
/* Fork from the parent process */
pid = fork();
if (pid < 0) {
/* some error happened */
return pid;
}
if (pid > 0) {
/* if we have received a positive PID, then we are the parent
* and can exit */
exit(0);
}
/* FIXME: do we really want this? */
umask(0);
/* Create a new session and set process group ID */
sid = setsid();
if (sid < 0)
return sid;
/* Change to the /tmp directory, which prevents the CWD from being locked
* and unable to remove it */
rc = chdir("/tmp");
if (rc < 0)
return rc;
/* Redirect stdio to /dev/null */
/* since C89/C99 says stderr is a macro, we can safely do this! */
#ifdef stderr
/*
* it does not make sense to check the return code here, so we just
* ignore the compiler warning from gcc
*/
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-result"
freopen("/dev/null", "r", stdin);
freopen("/dev/null", "w", stdout);
freopen("/dev/null", "w", stderr);
#pragma GCC diagnostic pop
#endif
return 0;
}
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