/* 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 */ }