signal.c

/*  Copyright 1996,1997,2001,2002,2007,2009 Alain Knaff.
 *  This file is part of mtools.
 *
 *  Mtools 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  Mtools 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 Mtools.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "sysincludes.h"
#include "mtools.h"

#undef got_signal

int got_signal = 0;

static void signal_handler(int dummy UNUSEDP)
{
	got_signal = 1;
#if 0
	signal(SIGHUP, SIG_IGN);
	signal(SIGINT, SIG_IGN);
	signal(SIGTERM, SIG_IGN);
	signal(SIGQUIT, SIG_IGN);
#endif
}

#if 0
int do_gotsignal(char *f, int n)
{
	if(got_signal)
		fprintf(stderr, "file=%s line=%d\n", f, n);
	return got_signal;
}
#endif

void setup_signal(void)
{
	/* catch signals */
#ifdef SIGHUP
	signal(SIGHUP, signal_handler);
#endif
#ifdef SIGINT
	signal(SIGINT, signal_handler);
#endif
#ifdef SIGTERM
	signal(SIGTERM, signal_handler);
#endif
#ifdef SIGQUIT
	signal(SIGQUIT, signal_handler);
#endif
}

#ifdef HAVE_SIGACTION
static void _allow_interrupt(saved_sig_state *ss, int sig, int slot)
{
  struct sigaction new;

  memset(&new, 0, sizeof(new));
  new.sa_handler = signal_handler;
  new.sa_flags &= ~SA_RESTART;

  if(sigaction(sig, &new, &ss->sa[slot]) < 0) {
    perror("sigaction");
    exit(1);
  }
}
#endif

/* Allow syscalls to be interrupted by signal */
void allow_interrupts(saved_sig_state *ss)
{
#ifdef HAVE_SIGACTION

# ifdef SIGHUP
  _allow_interrupt(ss, SIGINT, 0);
# endif

# ifdef SIGINT
  _allow_interrupt(ss, SIGINT, 1);
# endif

# ifdef SIGTERM
  _allow_interrupt(ss, SIGINT, 2);
# endif

# ifdef SIGQUIT
  _allow_interrupt(ss, SIGINT, 3);
# endif

#endif
}

#ifdef HAVE_SIGACTION
static void _restore_interrupt(saved_sig_state *ss, int sig, int slot)
{
  if(sigaction(sig, &ss->sa[slot], NULL) < 0) {
    perror("restore sigaction");
    exit(1);
  }
}
#endif

/* Restore syscalls to be interrupted by signal */
void restore_interrupts(saved_sig_state *ss)
{
#ifdef HAVE_SIGACTION

# ifdef SIGHUP
  _restore_interrupt(ss, SIGINT, 0);
# endif

# ifdef SIGINT
  _restore_interrupt(ss, SIGINT, 1);
# endif

# ifdef SIGTERM
  _restore_interrupt(ss, SIGINT, 2);
# endif

# ifdef SIGQUIT
  _restore_interrupt(ss, SIGINT, 3);
# endif

#endif
}