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/*
* ircsig.c: has a `my_signal()' that uses sigaction().
*
* Copyright (c) 1993-1996 Matthew R. Green.
* 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 of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* written by matthew green, 1993.
*
* i stole bits of this from w. richard stevens' `advanced programming
* in the unix environment' -mrg
*/
#include "irc.h"
#include "irc_std.h"
int block_signal (int sig_no)
{
sigset_t set;
sigemptyset(&set);
sigaddset(&set, sig_no);
return sigprocmask(SIG_BLOCK, &set, NULL);
}
int unblock_signal (int sig_no)
{
sigset_t set;
sigemptyset(&set);
sigaddset(&set, sig_no);
return sigprocmask(SIG_UNBLOCK, &set, NULL);
}
/* array of signal handlers containing mostly NULL */
sigfunc * signal_handlers[NSIG];
volatile sig_atomic_t signals_caught[NSIG];
/* grand unified signal handler, which sets flags for scriptable signals
* - pegasus
*/
static void signal_handler (int sig_no)
{
signals_caught[0] = 1;
signals_caught[sig_no]++;
if (signal_handlers[sig_no])
signal_handlers[sig_no](sig_no);
}
static sigfunc *reset_one_signal (int sig_no, sigfunc *sig_handler)
{
struct sigaction sa, osa;
if (sig_no < 0)
return NULL; /* Signal not implemented */
signal_handlers[sig_no] = NULL;
sa.sa_handler = sig_handler;
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, sig_no);
/* this is ugly, but the `correct' way. i hate c. -mrg */
sa.sa_flags = 0;
#if defined(SA_RESTART) || defined(SA_INTERRUPT)
if (SIGALRM == sig_no || SIGINT == sig_no)
{
# if defined(SA_INTERRUPT)
sa.sa_flags |= SA_INTERRUPT;
# endif /* SA_INTERRUPT */
}
else
{
# if defined(SA_RESTART)
sa.sa_flags |= SA_RESTART;
# endif /* SA_RESTART */
}
#endif /* SA_RESTART || SA_INTERRUPT */
if (0 > sigaction(sig_no, &sa, &osa))
return SIG_ERR;
return osa.sa_handler;
}
/* hook_all_signals needs to be called in main() before my_signal()
* if any signal hooks fail, it returns SIG_ERR, otherwise it returns
* NULL. - pegasus
*/
sigfunc * init_signals (void)
{
int sig_no;
sigfunc *error = NULL;
memset((void *)&signals_caught, 0, NSIG * sizeof(int));
for (sig_no = 1; sig_no < NSIG; sig_no++)
{
if ((reset_one_signal(sig_no, signal_handler)) == SIG_ERR)
error = SIG_ERR;
}
return error;
}
sigfunc * my_signal (int sig_no, sigfunc *sig_handler)
{
sigfunc *old;
old = signal_handlers[sig_no];
if (sig_handler == SIG_IGN || sig_handler == SIG_DFL)
reset_one_signal(sig_no, sig_handler);
else
{
reset_one_signal(sig_no, signal_handler);
signal_handlers[sig_no] = (sigfunc *)sig_handler;
}
return old;
}
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