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/*
** Zabbix
** Copyright (C) 2001-2019 Zabbix SIA
**
** 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.
**/
#include "common.h"
#include "sighandler.h"
#include "log.h"
#include "fatal.h"
#include "sigcommon.h"
#include "zbxcrypto.h"
int sig_parent_pid = -1;
volatile sig_atomic_t sig_exiting;
static void log_fatal_signal(int sig, siginfo_t *siginfo, void *context)
{
SIG_CHECK_PARAMS(sig, siginfo, context);
zabbix_log(LOG_LEVEL_CRIT, "Got signal [signal:%d(%s),reason:%d,refaddr:%p]. Crashing ...",
sig, get_signal_name(sig),
SIG_CHECKED_FIELD(siginfo, si_code),
SIG_CHECKED_FIELD_TYPE(siginfo, si_addr, void *));
}
static void exit_with_failure(void)
{
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
zbx_tls_free_on_signal();
#endif
_exit(EXIT_FAILURE);
}
/******************************************************************************
* *
* Function: fatal_signal_handler *
* *
* Purpose: handle fatal signals: SIGILL, SIGFPE, SIGSEGV, SIGBUS *
* *
******************************************************************************/
static void fatal_signal_handler(int sig, siginfo_t *siginfo, void *context)
{
log_fatal_signal(sig, siginfo, context);
zbx_log_fatal_info(context, ZBX_FATAL_LOG_FULL_INFO);
exit_with_failure();
}
/******************************************************************************
* *
* Function: metric_thread_signal_handler *
* *
* Purpose: same as fatal_signal_handler() but customized for metric thread - *
* does not log memory map *
* *
******************************************************************************/
static void metric_thread_signal_handler(int sig, siginfo_t *siginfo, void *context)
{
log_fatal_signal(sig, siginfo, context);
zbx_log_fatal_info(context, (ZBX_FATAL_LOG_PC_REG_SF | ZBX_FATAL_LOG_BACKTRACE));
exit_with_failure();
}
/******************************************************************************
* *
* Function: alarm_signal_handler *
* *
* Purpose: handle alarm signal SIGALRM *
* *
******************************************************************************/
static void alarm_signal_handler(int sig, siginfo_t *siginfo, void *context)
{
SIG_CHECK_PARAMS(sig, siginfo, context);
zbx_alarm_flag_set(); /* set alarm flag */
}
/******************************************************************************
* *
* Function: terminate_signal_handler *
* *
* Purpose: handle terminate signals: SIGHUP, SIGINT, SIGTERM, SIGUSR2 *
* *
******************************************************************************/
static void terminate_signal_handler(int sig, siginfo_t *siginfo, void *context)
{
int zbx_log_level_temp;
if (!SIG_PARENT_PROCESS)
{
/* the parent process can either politely ask a child process to finish it's work and perform cleanup */
/* by sending SIGUSR2 or terminate child process immediately without cleanup by sending SIGHUP */
if (SIGHUP == sig)
exit_with_failure();
if (SIGUSR2 == sig)
sig_exiting = 1;
}
else
{
SIG_CHECK_PARAMS(sig, siginfo, context);
if (0 == sig_exiting)
{
sig_exiting = 1;
/* temporary variable is used to avoid compiler warning */
zbx_log_level_temp = sig_parent_pid == SIG_CHECKED_FIELD(siginfo, si_pid) ?
LOG_LEVEL_DEBUG : LOG_LEVEL_WARNING;
zabbix_log(zbx_log_level_temp,
"Got signal [signal:%d(%s),sender_pid:%d,sender_uid:%d,"
"reason:%d]. Exiting ...",
sig, get_signal_name(sig),
SIG_CHECKED_FIELD(siginfo, si_pid),
SIG_CHECKED_FIELD(siginfo, si_uid),
SIG_CHECKED_FIELD(siginfo, si_code));
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
zbx_tls_free_on_signal();
#endif
zbx_on_exit(SUCCEED);
}
}
}
/******************************************************************************
* *
* Function: child_signal_handler *
* *
* Purpose: handle child signal SIGCHLD *
* *
******************************************************************************/
static void child_signal_handler(int sig, siginfo_t *siginfo, void *context)
{
SIG_CHECK_PARAMS(sig, siginfo, context);
if (!SIG_PARENT_PROCESS)
exit_with_failure();
if (0 == sig_exiting)
{
sig_exiting = 1;
zabbix_log(LOG_LEVEL_CRIT, "One child process died (PID:%d,exitcode/signal:%d). Exiting ...",
SIG_CHECKED_FIELD(siginfo, si_pid), SIG_CHECKED_FIELD(siginfo, si_status));
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
zbx_tls_free_on_signal();
#endif
zbx_on_exit(FAIL);
}
}
/******************************************************************************
* *
* Function: zbx_set_common_signal_handlers *
* *
* Purpose: set the commonly used signal handlers *
* *
******************************************************************************/
void zbx_set_common_signal_handlers(void)
{
struct sigaction phan;
sig_parent_pid = (int)getpid();
sigemptyset(&phan.sa_mask);
phan.sa_flags = SA_SIGINFO;
phan.sa_sigaction = terminate_signal_handler;
sigaction(SIGINT, &phan, NULL);
sigaction(SIGQUIT, &phan, NULL);
sigaction(SIGHUP, &phan, NULL);
sigaction(SIGTERM, &phan, NULL);
sigaction(SIGUSR2, &phan, NULL);
phan.sa_sigaction = fatal_signal_handler;
sigaction(SIGILL, &phan, NULL);
sigaction(SIGFPE, &phan, NULL);
sigaction(SIGSEGV, &phan, NULL);
sigaction(SIGBUS, &phan, NULL);
phan.sa_sigaction = alarm_signal_handler;
sigaction(SIGALRM, &phan, NULL);
}
/******************************************************************************
* *
* Function: zbx_set_child_signal_handler *
* *
* Purpose: set the handlers for child process signals *
* *
******************************************************************************/
void zbx_set_child_signal_handler(void)
{
struct sigaction phan;
sig_parent_pid = (int)getpid();
sigemptyset(&phan.sa_mask);
phan.sa_flags = SA_SIGINFO | SA_NOCLDSTOP;
phan.sa_sigaction = child_signal_handler;
sigaction(SIGCHLD, &phan, NULL);
}
/******************************************************************************
* *
* Function: zbx_set_metric_thread_signal_handler *
* *
* Purpose: set the handlers for child process signals *
* *
******************************************************************************/
void zbx_set_metric_thread_signal_handler(void)
{
struct sigaction phan;
sig_parent_pid = (int)getpid();
sigemptyset(&phan.sa_mask);
phan.sa_flags = SA_SIGINFO;
phan.sa_sigaction = metric_thread_signal_handler;
sigaction(SIGILL, &phan, NULL);
sigaction(SIGFPE, &phan, NULL);
sigaction(SIGSEGV, &phan, NULL);
sigaction(SIGBUS, &phan, NULL);
}
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