1 files changed, 479 insertions, 0 deletions
diff --git a/libs/libevent/src/signal.c b/libs/libevent/src/signal.c
new file mode 100644
index 0000000000..3f46295024
--- /dev/null
+++ b/libs/libevent/src/signal.c
@@ -0,0 +1,479 @@
+/*	$OpenBSD: select.c,v 1.2 2002/06/25 15:50:15 mickey Exp $	*/
+
+/*
+ * Copyright 2000-2007 Niels Provos <provos@citi.umich.edu>
+ * Copyright 2007-2012 Niels Provos and Nick Mathewson
+ *
+ * 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.
+ */
+#include "event2/event-config.h"
+#include "evconfig-private.h"
+
+#ifdef _WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <winsock2.h>
+#include <windows.h>
+#undef WIN32_LEAN_AND_MEAN
+#endif
+#include <sys/types.h>
+#ifdef EVENT__HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#include <sys/queue.h>
+#ifdef EVENT__HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifdef EVENT__HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <errno.h>
+#ifdef EVENT__HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#include "event2/event.h"
+#include "event2/event_struct.h"
+#include "event-internal.h"
+#include "event2/util.h"
+#include "evsignal-internal.h"
+#include "log-internal.h"
+#include "evmap-internal.h"
+#include "evthread-internal.h"
+
+/*
+  signal.c
+
+  This is the signal-handling implementation we use for backends that don't
+  have a better way to do signal handling.  It uses sigaction() or signal()
+  to set a signal handler, and a socket pair to tell the event base when
+
+  Note that I said "the event base" : only one event base can be set up to use
+  this at a time.  For historical reasons and backward compatibility, if you
+  add an event for a signal to event_base A, then add an event for a signal
+  (any signal!) to event_base B, event_base B will get informed about the
+  signal, but event_base A won't.
+
+  It would be neat to change this behavior in some future version of Libevent.
+  kqueue already does something far more sensible.  We can make all backends
+  on Linux do a reasonable thing using signalfd.
+*/
+
+#ifndef _WIN32
+/* Windows wants us to call our signal handlers as __cdecl.  Nobody else
+ * expects you to do anything crazy like this. */
+#define __cdecl
+#endif
+
+static int evsig_add(struct event_base *, evutil_socket_t, short, short, void *);
+static int evsig_del(struct event_base *, evutil_socket_t, short, short, void *);
+
+static const struct eventop evsigops = {
+	"signal",
+	NULL,
+	evsig_add,
+	evsig_del,
+	NULL,
+	NULL,
+	0, 0, 0
+};
+
+#ifndef EVENT__DISABLE_THREAD_SUPPORT
+/* Lock for evsig_base and evsig_base_n_signals_added fields. */
+static void *evsig_base_lock = NULL;
+#endif
+/* The event base that's currently getting informed about signals. */
+static struct event_base *evsig_base = NULL;
+/* A copy of evsig_base->sigev_n_signals_added. */
+static int evsig_base_n_signals_added = 0;
+static evutil_socket_t evsig_base_fd = -1;
+
+static void __cdecl evsig_handler(int sig);
+
+#define EVSIGBASE_LOCK() EVLOCK_LOCK(evsig_base_lock, 0)
+#define EVSIGBASE_UNLOCK() EVLOCK_UNLOCK(evsig_base_lock, 0)
+
+void
+evsig_set_base_(struct event_base *base)
+{
+	EVSIGBASE_LOCK();
+	evsig_base = base;
+	evsig_base_n_signals_added = base->sig.ev_n_signals_added;
+	evsig_base_fd = base->sig.ev_signal_pair[1];
+	EVSIGBASE_UNLOCK();
+}
+
+/* Callback for when the signal handler write a byte to our signaling socket */
+static void
+evsig_cb(evutil_socket_t fd, short what, void *arg)
+{
+	static char signals[1024];
+	ev_ssize_t n;
+	int i;
+	int ncaught[NSIG];
+	struct event_base *base;
+
+	base = arg;
+
+	memset(&ncaught, 0, sizeof(ncaught));
+
+	while (1) {
+#ifdef _WIN32
+		n = recv(fd, signals, sizeof(signals), 0);
+#else
+		n = read(fd, signals, sizeof(signals));
+#endif
+		if (n == -1) {
+			int err = evutil_socket_geterror(fd);
+			if (! EVUTIL_ERR_RW_RETRIABLE(err))
+				event_sock_err(1, fd, "%s: recv", __func__);
+			break;
+		} else if (n == 0) {
+			/* XXX warn? */
+			break;
+		}
+		for (i = 0; i < n; ++i) {
+			ev_uint8_t sig = signals[i];
+			if (sig < NSIG)
+				ncaught[sig]++;
+		}
+	}
+
+	EVBASE_ACQUIRE_LOCK(base, th_base_lock);
+	for (i = 0; i < NSIG; ++i) {
+		if (ncaught[i])
+			evmap_signal_active_(base, i, ncaught[i]);
+	}
+	EVBASE_RELEASE_LOCK(base, th_base_lock);
+}
+
+int
+evsig_init_(struct event_base *base)
+{
+	/*
+	 * 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 (evutil_make_internal_pipe_(base->sig.ev_signal_pair) == -1) {
+#ifdef _WIN32
+		/* Make this nonfatal on win32, where sometimes people
+		   have localhost firewalled. */
+		event_sock_warn(-1, "%s: socketpair", __func__);
+#else
+		event_sock_err(1, -1, "%s: socketpair", __func__);
+#endif
+		return -1;
+	}
+
+	if (base->sig.sh_old) {
+		mm_free(base->sig.sh_old);
+	}
+	base->sig.sh_old = NULL;
+	base->sig.sh_old_max = 0;
+
+	event_assign(&base->sig.ev_signal, base, base->sig.ev_signal_pair[0],
+		EV_READ | EV_PERSIST, evsig_cb, base);
+
+	base->sig.ev_signal.ev_flags |= EVLIST_INTERNAL;
+	event_priority_set(&base->sig.ev_signal, 0);
+
+	base->evsigsel = &evsigops;
+
+	return 0;
+}
+
+/* Helper: set the signal handler for evsignal to handler in base, so that
+ * we can restore the original handler when we clear the current one. */
+int
+evsig_set_handler_(struct event_base *base,
+    int evsignal, void (__cdecl *handler)(int))
+{
+#ifdef EVENT__HAVE_SIGACTION
+	struct sigaction sa;
+#else
+	ev_sighandler_t sh;
+#endif
+	struct evsig_info *sig = &base->sig;
+	void *p;
+
+	/*
+	 * resize saved signal handler array up to the highest signal number.
+	 * a dynamic array is used to keep footprint on the low side.
+	 */
+	if (evsignal >= sig->sh_old_max) {
+		int new_max = evsignal + 1;
+		event_debug(("%s: evsignal (%d) >= sh_old_max (%d), resizing",
+			    __func__, evsignal, sig->sh_old_max));
+		p = mm_realloc(sig->sh_old, new_max * sizeof(*sig->sh_old));
+		if (p == NULL) {
+			event_warn("realloc");
+			return (-1);
+		}
+
+		memset((char *)p + sig->sh_old_max * sizeof(*sig->sh_old),
+		    0, (new_max - sig->sh_old_max) * sizeof(*sig->sh_old));
+
+		sig->sh_old_max = new_max;
+		sig->sh_old = p;
+	}
+
+	/* allocate space for previous handler out of dynamic array */
+	sig->sh_old[evsignal] = mm_malloc(sizeof *sig->sh_old[evsignal]);
+	if (sig->sh_old[evsignal] == NULL) {
+		event_warn("malloc");
+		return (-1);
+	}
+
+	/* save previous handler and setup new handler */
+#ifdef EVENT__HAVE_SIGACTION
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = handler;
+	sa.sa_flags |= SA_RESTART;
+	sigfillset(&sa.sa_mask);
+
+	if (sigaction(evsignal, &sa, sig->sh_old[evsignal]) == -1) {
+		event_warn("sigaction");
+		mm_free(sig->sh_old[evsignal]);
+		sig->sh_old[evsignal] = NULL;
+		return (-1);
+	}
+#else
+	if ((sh = signal(evsignal, handler)) == SIG_ERR) {
+		event_warn("signal");
+		mm_free(sig->sh_old[evsignal]);
+		sig->sh_old[evsignal] = NULL;
+		return (-1);
+	}
+	*sig->sh_old[evsignal] = sh;
+#endif
+
+	return (0);
+}
+
+static int
+evsig_add(struct event_base *base, evutil_socket_t evsignal, short old, short events, void *p)
+{
+	struct evsig_info *sig = &base->sig;
+	(void)p;
+
+	EVUTIL_ASSERT(evsignal >= 0 && evsignal < NSIG);
+
+	/* catch signals if they happen quickly */
+	EVSIGBASE_LOCK();
+	if (evsig_base != base && evsig_base_n_signals_added) {
+		event_warnx("Added a signal to event base %p with signals "
+		    "already added to event_base %p.  Only one can have "
+		    "signals at a time with the %s backend.  The base with "
+		    "the most recently added signal or the most recent "
+		    "event_base_loop() call gets preference; do "
+		    "not rely on this behavior in future Libevent versions.",
+		    base, evsig_base, base->evsel->name);
+	}
+	evsig_base = base;
+	evsig_base_n_signals_added = ++sig->ev_n_signals_added;
+	evsig_base_fd = base->sig.ev_signal_pair[1];
+	EVSIGBASE_UNLOCK();
+
+	event_debug(("%s: %d: changing signal handler", __func__, (int)evsignal));
+	if (evsig_set_handler_(base, (int)evsignal, evsig_handler) == -1) {
+		goto err;
+	}
+
+
+	if (!sig->ev_signal_added) {
+		if (event_add_nolock_(&sig->ev_signal, NULL, 0))
+			goto err;
+		sig->ev_signal_added = 1;
+	}
+
+	return (0);
+
+err:
+	EVSIGBASE_LOCK();
+	--evsig_base_n_signals_added;
+	--sig->ev_n_signals_added;
+	EVSIGBASE_UNLOCK();
+	return (-1);
+}
+
+int
+evsig_restore_handler_(struct event_base *base, int evsignal)
+{
+	int ret = 0;
+	struct evsig_info *sig = &base->sig;
+#ifdef EVENT__HAVE_SIGACTION
+	struct sigaction *sh;
+#else
+	ev_sighandler_t *sh;
+#endif
+
+	if (evsignal >= sig->sh_old_max) {
+		/* Can't actually restore. */
+		/* XXXX.*/
+		return 0;
+	}
+
+	/* restore previous handler */
+	sh = sig->sh_old[evsignal];
+	sig->sh_old[evsignal] = NULL;
+#ifdef EVENT__HAVE_SIGACTION
+	if (sigaction(evsignal, sh, NULL) == -1) {
+		event_warn("sigaction");
+		ret = -1;
+	}
+#else
+	if (signal(evsignal, *sh) == SIG_ERR) {
+		event_warn("signal");
+		ret = -1;
+	}
+#endif
+
+	mm_free(sh);
+
+	return ret;
+}
+
+static int
+evsig_del(struct event_base *base, evutil_socket_t evsignal, short old, short events, void *p)
+{
+	EVUTIL_ASSERT(evsignal >= 0 && evsignal < NSIG);
+
+	event_debug(("%s: "EV_SOCK_FMT": restoring signal handler",
+		__func__, EV_SOCK_ARG(evsignal)));
+
+	EVSIGBASE_LOCK();
+	--evsig_base_n_signals_added;
+	--base->sig.ev_n_signals_added;
+	EVSIGBASE_UNLOCK();
+
+	return (evsig_restore_handler_(base, (int)evsignal));
+}
+
+static void __cdecl
+evsig_handler(int sig)
+{
+	int save_errno = errno;
+#ifdef _WIN32
+	int socket_errno = EVUTIL_SOCKET_ERROR();
+#endif
+	ev_uint8_t msg;
+
+	if (evsig_base == NULL) {
+		event_warnx(
+			"%s: received signal %d, but have no base configured",
+			__func__, sig);
+		return;
+	}
+
+#ifndef EVENT__HAVE_SIGACTION
+	signal(sig, evsig_handler);
+#endif
+
+	/* Wake up our notification mechanism */
+	msg = sig;
+#ifdef _WIN32
+	send(evsig_base_fd, (char*)&msg, 1, 0);
+#else
+	{
+		int r = write(evsig_base_fd, (char*)&msg, 1);
+		(void)r; /* Suppress 'unused return value' and 'unused var' */
+	}
+#endif
+	errno = save_errno;
+#ifdef _WIN32
+	EVUTIL_SET_SOCKET_ERROR(socket_errno);
+#endif
+}
+
+void
+evsig_dealloc_(struct event_base *base)
+{
+	int i = 0;
+	if (base->sig.ev_signal_added) {
+		event_del(&base->sig.ev_signal);
+		base->sig.ev_signal_added = 0;
+	}
+	/* debug event is created in evsig_init_/event_assign even when
+	 * ev_signal_added == 0, so unassign is required */
+	event_debug_unassign(&base->sig.ev_signal);
+
+	for (i = 0; i < NSIG; ++i) {
+		if (i < base->sig.sh_old_max && base->sig.sh_old[i] != NULL)
+			evsig_restore_handler_(base, i);
+	}
+	EVSIGBASE_LOCK();
+	if (base == evsig_base) {
+		evsig_base = NULL;
+		evsig_base_n_signals_added = 0;
+		evsig_base_fd = -1;
+	}
+	EVSIGBASE_UNLOCK();
+
+	if (base->sig.ev_signal_pair[0] != -1) {
+		evutil_closesocket(base->sig.ev_signal_pair[0]);
+		base->sig.ev_signal_pair[0] = -1;
+	}
+	if (base->sig.ev_signal_pair[1] != -1) {
+		evutil_closesocket(base->sig.ev_signal_pair[1]);
+		base->sig.ev_signal_pair[1] = -1;
+	}
+	base->sig.sh_old_max = 0;
+
+	/* per index frees are handled in evsig_del() */
+	if (base->sig.sh_old) {
+		mm_free(base->sig.sh_old);
+		base->sig.sh_old = NULL;
+	}
+}
+
+static void
+evsig_free_globals_locks(void)
+{
+#ifndef EVENT__DISABLE_THREAD_SUPPORT
+	if (evsig_base_lock != NULL) {
+		EVTHREAD_FREE_LOCK(evsig_base_lock, 0);
+		evsig_base_lock = NULL;
+	}
+#endif
+	return;
+}
+
+void
+evsig_free_globals_(void)
+{
+	evsig_free_globals_locks();
+}
+
+#ifndef EVENT__DISABLE_THREAD_SUPPORT
+int
+evsig_global_setup_locks_(const int enable_locks)
+{
+	EVTHREAD_SETUP_GLOBAL_LOCK(evsig_base_lock, 0);
+	return 0;
+}
+
+#endif