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/*
* Copyright (c) 2009 Mark Heily <mark@heily.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, 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.
*/
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <string.h>
#include <unistd.h>
#include "sys/event.h"
#include "private.h"
/* Highest signal number supported. POSIX standard signals are < 32 */
#define SIGNAL_MAX 32
struct sentry {
struct filter *s_filt;
struct knote *s_knote;
volatile uint32_t s_cnt;
};
static pthread_mutex_t sigtbl_mtx = PTHREAD_MUTEX_INITIALIZER;
static struct sentry sigtbl[SIGNAL_MAX];
static void
signal_handler(int sig)
{
struct sentry *s = &sigtbl[sig];
dbg_printf("caught sig=%d", sig);
atomic_inc(&s->s_cnt);
#if defined(__sun__)
if (port_send(s->s_filt->kf_kqueue->kq_port,
X_PORT_SOURCE_SIGNAL, &sigtbl[sig]) < 0) {
return; //FIXME: errorhandling
}
#else
(void)write(s->s_filt->kf_wfd, &sig, sizeof(sig));//FIXME:errhandling
#endif
}
static int
catch_signal(struct filter *filt, struct knote *kn)
{
int sig;
struct sigaction sa;
sig = kn->kev.ident;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = signal_handler;
sa.sa_flags |= SA_RESTART;
sigfillset(&sa.sa_mask);
if (sigaction(kn->kev.ident, &sa, NULL) == -1) {
dbg_perror("sigaction");
return (-1);
}
/* FIXME: will clobber previous entry, if any */
pthread_mutex_lock(&sigtbl_mtx);
sigtbl[kn->kev.ident].s_filt = filt;
sigtbl[kn->kev.ident].s_knote = kn;
pthread_mutex_unlock(&sigtbl_mtx);
dbg_printf("installed handler for signal %d", sig);
return (0);
}
static int
ignore_signal(int sig)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_IGN;
sigemptyset(&sa.sa_mask);
if (sigaction(sig, &sa, NULL) == -1) {
dbg_perror("sigaction");
return (-1);
}
pthread_mutex_lock(&sigtbl_mtx);
sigtbl[sig].s_filt = NULL;
sigtbl[sig].s_knote = NULL;
pthread_mutex_unlock(&sigtbl_mtx);
dbg_printf("removed handler for signal %d", sig);
return (0);
}
int
evfilt_signal_init(struct filter *filt)
{
return filter_socketpair(filt);
}
void
evfilt_signal_destroy(struct filter *filt)
{
close(filt->kf_pfd);
}
int
evfilt_signal_knote_create(struct filter *filt, struct knote *kn)
{
if (kn->kev.ident >= SIGNAL_MAX) {
dbg_printf("unsupported signal number %u",
(unsigned int) kn->kev.ident);
return (-1);
}
kn->kev.flags |= EV_CLEAR;
return catch_signal(filt, kn);
}
int
evfilt_signal_knote_modify(struct filter *filt, struct knote *kn,
const struct kevent *kev)
{
kn->kev.flags = kev->flags | EV_CLEAR;
return (0);
}
int
evfilt_signal_knote_delete(struct filter *filt, struct knote *kn)
{
return ignore_signal(kn->kev.ident);
}
int
evfilt_signal_knote_enable(struct filter *filt, struct knote *kn)
{
return catch_signal(filt, kn);
}
int
evfilt_signal_knote_disable(struct filter *filt, struct knote *kn)
{
return ignore_signal(kn->kev.ident);
}
int
evfilt_signal_copyout(struct filter *filt,
struct kevent *dst,
int nevents)
{
struct sentry *s;
struct knote *kn;
int sig;
#if defined(__sun__)
port_event_t *pe = (port_event_t *) pthread_getspecific(filt->kf_kqueue->kq_port_event);
s = (struct sentry *) pe->portev_user;
sig = s - &sigtbl[0];
#else
read(filt->kf_pfd, &sig, sizeof(sig));//FIXME:errhandling
s = &sigtbl[sig];
#endif
kn = s->s_knote;
//TODO: READ counter: s->s_knote->kev.data = ?;
/* TODO: dst->data should be the number of times the signal occurred */
dst->ident = sig;
dst->filter = EVFILT_SIGNAL;
dst->udata = kn->kev.udata;
dst->flags = kn->kev.flags;
dst->fflags = 0;
dst->data = 1;
if (kn->kev.flags & EV_DISPATCH) {
ignore_signal(kn->kev.ident);
KNOTE_DISABLE(kn);
} else if (kn->kev.flags & EV_ONESHOT) {
ignore_signal(kn->kev.ident);
knote_free(filt, kn);
}
return (1);
}
const struct filter evfilt_signal = {
EVFILT_SIGNAL,
evfilt_signal_init,
evfilt_signal_destroy,
evfilt_signal_copyout,
evfilt_signal_knote_create,
evfilt_signal_knote_modify,
evfilt_signal_knote_delete,
evfilt_signal_knote_enable,
evfilt_signal_knote_disable,
};
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