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/* $OpenBSD: signal.c,v 1.10 2005/12/02 16:54:25 deraadt Exp $ */
/*
* Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
* 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 AUTHOR ``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 AUTHOR 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <sys/_time.h>
#endif
#include <sys/queue.h>
#include <sys/socket.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include "event.h"
#include "evsignal.h"
#include "log.h"
extern struct event_list signalqueue;
static sig_atomic_t evsigcaught[NSIG];
static int needrecalc;
volatile sig_atomic_t evsignal_caught = 0;
static struct event ev_signal;
static int ev_signal_pair[2];
static int ev_signal_added;
/* Callback for when the signal handler write a byte to our signaling socket */
static void
evsignal_cb(int fd, short what, void *arg)
{
static char signals[100];
struct event *ev = arg;
ssize_t n;
n = read(fd, signals, sizeof(signals));
if (n == -1)
event_err(1, "%s: read", __func__);
event_add(ev, NULL);
}
#ifdef HAVE_SETFD
#define FD_CLOSEONEXEC(x) do { \
if (fcntl(x, F_SETFD, 1) == -1) \
event_warn("fcntl(%d, F_SETFD)", x); \
} while (0)
#else
#define FD_CLOSEONEXEC(x)
#endif
void
evsignal_init(sigset_t *evsigmask)
{
sigemptyset(evsigmask);
/*
* Our signal handler is going to write to one end of the socket
* pair to wake up our event loop. The event loop then scans for
* signals that got delivered.
*/
if (socketpair(AF_UNIX, SOCK_STREAM, 0, ev_signal_pair) == -1)
event_err(1, "%s: socketpair", __func__);
FD_CLOSEONEXEC(ev_signal_pair[0]);
FD_CLOSEONEXEC(ev_signal_pair[1]);
fcntl(ev_signal_pair[0], F_SETFL, O_NONBLOCK);
event_set(&ev_signal, ev_signal_pair[1], EV_READ,
evsignal_cb, &ev_signal);
ev_signal.ev_flags |= EVLIST_INTERNAL;
}
int
evsignal_add(sigset_t *evsigmask, struct event *ev)
{
int evsignal;
if (ev->ev_events & (EV_READ|EV_WRITE))
event_errx(1, "%s: EV_SIGNAL incompatible use", __func__);
evsignal = EVENT_SIGNAL(ev);
sigaddset(evsigmask, evsignal);
return (0);
}
/*
* Nothing to be done here.
*/
int
evsignal_del(sigset_t *evsigmask, struct event *ev)
{
int evsignal;
evsignal = EVENT_SIGNAL(ev);
sigdelset(evsigmask, evsignal);
needrecalc = 1;
return (sigaction(EVENT_SIGNAL(ev),(struct sigaction *)SIG_DFL, NULL));
}
static void
evsignal_handler(int sig)
{
int save_errno = errno;
evsigcaught[sig]++;
evsignal_caught = 1;
/* Wake up our notification mechanism */
write(ev_signal_pair[0], "a", 1);
errno = save_errno;
}
int
evsignal_recalc(sigset_t *evsigmask)
{
struct sigaction sa;
struct event *ev;
if (!ev_signal_added) {
ev_signal_added = 1;
event_add(&ev_signal, NULL);
}
if (TAILQ_FIRST(&signalqueue) == NULL && !needrecalc)
return (0);
needrecalc = 0;
if (sigprocmask(SIG_BLOCK, evsigmask, NULL) == -1)
return (-1);
/* Reinstall our signal handler. */
memset(&sa, 0, sizeof(sa));
sa.sa_handler = evsignal_handler;
sa.sa_mask = *evsigmask;
sa.sa_flags |= SA_RESTART;
TAILQ_FOREACH(ev, &signalqueue, ev_signal_next) {
if (sigaction(EVENT_SIGNAL(ev), &sa, NULL) == -1)
return (-1);
}
return (0);
}
int
evsignal_deliver(sigset_t *evsigmask)
{
if (TAILQ_FIRST(&signalqueue) == NULL)
return (0);
return (sigprocmask(SIG_UNBLOCK, evsigmask, NULL));
/* XXX - pending signals handled here */
}
void
evsignal_process(void)
{
struct event *ev;
sig_atomic_t ncalls;
TAILQ_FOREACH(ev, &signalqueue, ev_signal_next) {
ncalls = evsigcaught[EVENT_SIGNAL(ev)];
if (ncalls) {
if (!(ev->ev_events & EV_PERSIST))
event_del(ev);
event_active(ev, EV_SIGNAL, ncalls);
}
}
memset(evsigcaught, 0, sizeof(evsigcaught));
evsignal_caught = 0;
}
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