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/*
* rngd_signals.c -- Signal handling
*
* Copyright (C) 2004 Henrique de Moraes Holschuh <hmh@debian.org>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "rng-tools-config.h"
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <signal.h>
#include <errno.h>
#include "rngd.h"
#include "exits.h"
#include "rngd_signals.h"
#include "rngd_threads.h"
/* Signals, set to non-zero when a signal is received */
volatile sig_atomic_t gotsigterm = 0; /* SIGTERM/SIGINT */
volatile sig_atomic_t gotsigusr1 = 0; /* SIGUSR1 */
volatile sig_atomic_t gotsigalrm = 0; /* SIGALRM */
/* Only one SIGARLM user at a time... */
static pthread_mutex_t sigalrm_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_t sigalrm_owner;
static unsigned int sigalrm_installed = 0;
/* Signal handlers */
static void sigterm_handler(int sig)
{
gotsigterm = 128 | sig;
}
static void sigusr1_handler(int sig)
{
gotsigusr1 = 1;
}
static void sigalrm_handler(int sig)
{
gotsigalrm = 1;
}
/* Enable SIGALRM */
int enable_sigalrm(unsigned int seconds)
{
sigset_t sigs;
struct sigaction action;
int result = 0;
pthread_mutex_lock(&sigalrm_mutex);
if (sigalrm_installed == 0 ||
pthread_equal(pthread_self(), sigalrm_owner)) {
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
action.sa_handler = sigalrm_handler;
if (sigaction(SIGALRM, &action, NULL) < 0) {
message_strerr(LOG_ERR, errno,
"unable to install signal handler for SIGARLM");
result = -1;
} else {
sigemptyset(&sigs);
sigaddset(&sigs, SIGALRM);
pthread_sigmask(SIG_UNBLOCK, &sigs, NULL);
sigalrm_installed = 1;
sigalrm_owner = pthread_self();
gotsigalrm = 0;
alarm(seconds);
}
} else {
message(LOG_ERR,
"PROGRAM FAILURE DETECTED: two threads trying to use SIGARLM at the same time");
result = -1;
}
pthread_mutex_unlock(&sigalrm_mutex);
return result;
}
/* Disable SIGALRM */
int disable_sigalrm(void)
{
sigset_t sig;
sigemptyset(&sig);
sigaddset(&sig, SIGALRM);
pthread_sigmask(SIG_BLOCK, &sig, NULL);
pthread_mutex_lock(&sigalrm_mutex);
if (sigalrm_installed != 0 &&
pthread_equal(pthread_self(), sigalrm_owner)) {
alarm(0);
sigalrm_installed = 0;
}
pthread_mutex_unlock(&sigalrm_mutex);
return 0;
}
/* Init signal handlers */
void init_sighandlers(void)
{
sigset_t sigs;
struct sigaction action;
/* Initialize signal mask */
sigemptyset(&sigs);
pthread_sigmask(SIG_SETMASK, &sigs, NULL);
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
action.sa_handler = sigterm_handler;
/* Handle SIGTERM and SIGINT the same way */
if (sigaction(SIGTERM, &action, NULL) < 0) {
message_strerr(LOG_ERR, errno,
"unable to install signal handler for SIGTERM");
die(EXIT_OSERR);
}
if (sigaction(SIGINT, &action, NULL) < 0) {
message_strerr(LOG_ERR, errno,
"unable to install signal handler for SIGINT");
die(EXIT_OSERR);
}
/* Handle SIGUSR1 in a more friendly way */
action.sa_flags = SA_RESTART;
action.sa_handler = sigusr1_handler;
if (sigaction(SIGUSR1, &action, NULL) < 0) {
message_strerr(LOG_ERR, errno,
"unable to install signal handler for SIGUSR1");
die(EXIT_OSERR);
}
gotsigterm = gotsigusr1 = 0;
sigemptyset(&sigs);
sigaddset(&sigs, SIGTERM);
sigaddset(&sigs, SIGINT);
sigaddset(&sigs, SIGUSR1);
pthread_sigmask(SIG_UNBLOCK, &sigs, NULL);
}
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