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/*
* sighandler.c
*
* Copyright (c) 2015-2019 Pacman Development Team <pacman-dev@archlinux.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, see <http://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include <alpm.h>
#include "conf.h"
#include "sighandler.h"
#include "util.h"
/** Write function that correctly handles EINTR.
*/
static ssize_t xwrite(int fd, const void *buf, size_t count)
{
ssize_t ret;
do {
ret = write(fd, buf, count);
} while(ret == -1 && errno == EINTR);
return ret;
}
static void _reset_handler(int signum)
{
struct sigaction new_action;
sigemptyset(&new_action.sa_mask);
new_action.sa_handler = SIG_DFL;
new_action.sa_flags = 0;
sigaction(signum, &new_action, NULL);
}
/** Catches thrown signals. Performs necessary cleanup to ensure database is
* in a consistent state.
* @param signum the thrown signal
*/
static void soft_interrupt_handler(int signum)
{
if(signum == SIGINT) {
const char msg[] = "\nInterrupt signal received\n";
xwrite(STDERR_FILENO, msg, ARRAYSIZE(msg) - 1);
} else {
const char msg[] = "\nHangup signal received\n";
xwrite(STDERR_FILENO, msg, ARRAYSIZE(msg) - 1);
}
if(alpm_trans_interrupt(config->handle) == 0) {
/* a transaction is being interrupted, don't exit pacman yet. */
return;
}
alpm_unlock(config->handle);
/* output a newline to be sure we clear any line we may be on */
xwrite(STDOUT_FILENO, "\n", 1);
_Exit(128 + signum);
}
void install_soft_interrupt_handler(void)
{
struct sigaction new_action;
new_action.sa_handler = soft_interrupt_handler;
new_action.sa_flags = SA_RESTART;
sigemptyset(&new_action.sa_mask);
sigaddset(&new_action.sa_mask, SIGINT);
sigaddset(&new_action.sa_mask, SIGHUP);
sigaction(SIGINT, &new_action, NULL);
sigaction(SIGHUP, &new_action, NULL);
}
void remove_soft_interrupt_handler(void)
{
_reset_handler(SIGINT);
_reset_handler(SIGHUP);
}
static void segv_handler(int signum)
{
sigset_t segvset;
const char msg[] = "\nerror: segmentation fault\n"
"Please submit a full bug report with --debug if appropriate.\n";
xwrite(STDERR_FILENO, msg, sizeof(msg) - 1);
/* restore the default handler */
_reset_handler(signum);
/* unblock SIGSEGV */
sigaddset(&segvset, signum);
sigprocmask(SIG_UNBLOCK, &segvset, NULL);
/* re-raise to trigger a core dump */
raise(signum);
/* raise should immediately abort, but just to make absolutely sure */
_Exit(signum);
}
void install_segv_handler(void)
{
struct sigaction new_action;
new_action.sa_handler = segv_handler;
sigfillset(&new_action.sa_mask);
new_action.sa_flags = SA_RESTART;
sigaction(SIGSEGV, &new_action, NULL);
}
static void winch_handler(int signum)
{
(void)signum; /* suppress unused variable warnings */
columns_cache_reset();
}
void install_winch_handler(void)
{
struct sigaction new_action;
new_action.sa_handler = winch_handler;
sigemptyset(&new_action.sa_mask);
new_action.sa_flags = SA_RESTART;
sigaction(SIGWINCH, &new_action, NULL);
}
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