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/* signals.c -- signal handling functions to allow clean shutdown
* Copyright (c) 1998-2003 Carnegie Mellon University. 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. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any other legal
* details, please contact
* Office of Technology Transfer
* Carnegie Mellon University
* 5000 Forbes Avenue
* Pittsburgh, PA 15213-3890
* (412) 268-4387, fax: (412) 268-7395
* tech-transfer@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: signals.c,v 1.13 2005/02/14 16:26:50 shadow Exp $ */
#include <config.h>
#include <stdlib.h>
#include <signal.h>
#include <syslog.h>
#include "signals.h"
#include "xmalloc.h"
#include "exitcodes.h"
static int gotsignal = 0;
static void sighandler(int sig)
{
/* syslog(LOG_DEBUG, "got signal %d", sig); */
gotsignal = sig;
}
static const int catch[] = { SIGHUP, SIGINT, SIGQUIT, 0 };
void signals_add_handlers(int alarm)
{
struct sigaction action;
int i;
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
#ifdef SA_RESETHAND
action.sa_flags |= SA_RESETHAND;
#endif
action.sa_handler = sighandler;
/* SIGALRM used as a syscall timeout, so we don't set SA_RESTART */
if (alarm && sigaction(SIGALRM, &action, NULL) < 0) {
fatal("unable to install signal handler for %d: %m", SIGALRM);
}
#ifdef SA_RESTART
action.sa_flags |= SA_RESTART;
#endif
for (i = 0; catch[i] != 0; i++) {
if (catch[i] != SIGALRM && sigaction(catch[i], &action, NULL) < 0) {
fatal("unable to install signal handler for %d: %m", catch[i]);
}
}
}
static shutdownfn *shutdown_cb = NULL;
void signals_set_shutdown(shutdownfn *s)
{
shutdown_cb = s;
}
int signals_poll(void)
{
switch (gotsignal) {
case SIGINT:
case SIGQUIT:
if (shutdown_cb) shutdown_cb(EC_TEMPFAIL);
else exit(EC_TEMPFAIL);
break;
default:
return gotsignal;
break;
}
return 0; /* compiler warning stupidity */
}
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