X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fevent.c;h=1283edd332b8334fa8fc78a6faedb03d2a397516;hp=5cf8b48b4cc22d5865fe44c43e95c10c03c5589e;hb=d6b45d005530496e48325a6174ecdd889a17bfc1;hpb=df3220a1549f992cbf4a9b6e67c1e67b69896c7d

diff --git a/src/event.c b/src/event.c
index 5cf8b48b..1283edd3 100644
--- a/src/event.c
+++ b/src/event.c
@@ -1,7 +1,6 @@
 /*
-    event.c -- event queue
-    Copyright (C) 2002-2005 Guus Sliepen <guus@tinc-vpn.org>,
-                  2002-2005 Ivo Timmermans <ivo@tinc-vpn.org>
+    event.c -- I/O, timeout and signal event handling
+    Copyright (C) 2012-2018 Guus Sliepen <guus@tinc-vpn.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
@@ -13,93 +12,478 @@
     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, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-    $Id$
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
 #include "system.h"
 
-#include "avl_tree.h"
+#include "dropin.h"
 #include "event.h"
+#include "net.h"
 #include "utils.h"
 #include "xalloc.h"
 
-avl_tree_t *event_tree;
-extern time_t now;
+struct timeval now;
+
+#ifndef HAVE_MINGW
+static fd_set readfds;
+static fd_set writefds;
+#else
+static const long READ_EVENTS = FD_READ | FD_ACCEPT | FD_CLOSE;
+static const long WRITE_EVENTS = FD_WRITE | FD_CONNECT;
+static DWORD event_count = 0;
+#endif
+static bool running;
+
+static int io_compare(const io_t *a, const io_t *b) {
+#ifndef HAVE_MINGW
+	return a->fd - b->fd;
+#else
+
+	if(a->event < b->event) {
+		return -1;
+	}
+
+	if(a->event > b->event) {
+		return 1;
+	}
+
+	return 0;
+#endif
+}
+
+static int timeout_compare(const timeout_t *a, const timeout_t *b) {
+	struct timeval diff;
+	timersub(&a->tv, &b->tv, &diff);
+
+	if(diff.tv_sec < 0) {
+		return -1;
+	}
+
+	if(diff.tv_sec > 0) {
+		return 1;
+	}
 
-int id;
+	if(diff.tv_usec < 0) {
+		return -1;
+	}
 
-static int event_compare(const event_t *a, const event_t *b)
-{
-	if(a->time > b->time)
+	if(diff.tv_usec > 0) {
 		return 1;
+	}
 
-	if(a->time < b->time)
+	if(a < b) {
 		return -1;
+	}
+
+	if(a > b) {
+		return 1;
+	}
+
+	return 0;
+}
+
+static splay_tree_t io_tree = {.compare = (splay_compare_t)io_compare};
+static splay_tree_t timeout_tree = {.compare = (splay_compare_t)timeout_compare};
+
+void io_add(io_t *io, io_cb_t cb, void *data, int fd, int flags) {
+	if(io->cb) {
+		return;
+	}
+
+	io->fd = fd;
+#ifdef HAVE_MINGW
+
+	if(io->fd != -1) {
+		io->event = WSACreateEvent();
+
+		if(io->event == WSA_INVALID_EVENT) {
+			abort();
+		}
+	}
+
+	event_count++;
+#endif
+	io->cb = cb;
+	io->data = data;
+	io->node.data = io;
 
-	return a->id - b->id;
+	io_set(io, flags);
+
+	if(!splay_insert_node(&io_tree, &io->node)) {
+		abort();
+	}
 }
 
-void init_events(void)
-{
-	cp();
+#ifdef HAVE_MINGW
+void io_add_event(io_t *io, io_cb_t cb, void *data, WSAEVENT event) {
+	io->event = event;
+	io_add(io, cb, data, -1, 0);
+}
+#endif
+
+void io_set(io_t *io, int flags) {
+	if(flags == io->flags) {
+		return;
+	}
+
+	io->flags = flags;
+
+	if(io->fd == -1) {
+		return;
+	}
+
+#ifndef HAVE_MINGW
+
+	if(flags & IO_READ) {
+		FD_SET(io->fd, &readfds);
+	} else {
+		FD_CLR(io->fd, &readfds);
+	}
+
+	if(flags & IO_WRITE) {
+		FD_SET(io->fd, &writefds);
+	} else {
+		FD_CLR(io->fd, &writefds);
+	}
+
+#else
+	long events = 0;
+
+	if(flags & IO_WRITE) {
+		events |= WRITE_EVENTS;
+	}
+
+	if(flags & IO_READ) {
+		events |= READ_EVENTS;
+	}
+
+	if(WSAEventSelect(io->fd, io->event, events) != 0) {
+		abort();
+	}
 
-	event_tree = avl_alloc_tree((avl_compare_t) event_compare, NULL);
+#endif
 }
 
-void exit_events(void)
-{
-	cp();
+void io_del(io_t *io) {
+	if(!io->cb) {
+		return;
+	}
 
-	avl_delete_tree(event_tree);
+	io_set(io, 0);
+#ifdef HAVE_MINGW
+
+	if(io->fd != -1 && WSACloseEvent(io->event) == FALSE) {
+		abort();
+	}
+
+	event_count--;
+#endif
+
+	splay_unlink_node(&io_tree, &io->node);
+	io->cb = NULL;
 }
 
-event_t *new_event(void)
-{
-	cp();
+void timeout_add(timeout_t *timeout, timeout_cb_t cb, void *data, struct timeval *tv) {
+	timeout->cb = cb;
+	timeout->data = data;
+	timeout->node.data = timeout;
 
-	return xmalloc_and_zero(sizeof(event_t));
+	timeout_set(timeout, tv);
 }
 
-void free_event(event_t *event)
-{
-	cp();
+void timeout_set(timeout_t *timeout, struct timeval *tv) {
+	if(timerisset(&timeout->tv)) {
+		splay_unlink_node(&timeout_tree, &timeout->node);
+	}
+
+	if(!now.tv_sec) {
+		gettimeofday(&now, NULL);
+	}
+
+	timeradd(&now, tv, &timeout->tv);
 
-	free(event);
+	if(!splay_insert_node(&timeout_tree, &timeout->node)) {
+		abort();
+	}
 }
 
-void event_add(event_t *event)
-{
-	cp();
+void timeout_del(timeout_t *timeout) {
+	if(!timeout->cb) {
+		return;
+	}
 
-	event->id = ++id;
-	avl_insert(event_tree, event);
+	splay_unlink_node(&timeout_tree, &timeout->node);
+	timeout->cb = 0;
+	timeout->tv = (struct timeval) {
+		0, 0
+	};
 }
 
-void event_del(event_t *event)
-{
-	cp();
+#ifndef HAVE_MINGW
+static int signal_compare(const signal_t *a, const signal_t *b) {
+	return a->signum - b->signum;
+}
 
-	avl_delete(event_tree, event);
+static io_t signalio;
+static int pipefd[2] = {-1, -1};
+static splay_tree_t signal_tree = {.compare = (splay_compare_t)signal_compare};
+
+static void signal_handler(int signum) {
+	unsigned char num = signum;
+	write(pipefd[1], &num, 1);
 }
 
-event_t *get_expired_event(void)
-{
-	event_t *event;
+static void signalio_handler(void *data, int flags) {
+	(void)data;
+	(void)flags;
+	unsigned char signum;
 
-	cp();
+	if(read(pipefd[0], &signum, 1) != 1) {
+		return;
+	}
 
-	if(event_tree->head) {
-		event = event_tree->head->data;
+	signal_t *sig = splay_search(&signal_tree, &((signal_t) {
+		.signum = signum
+	}));
 
-		if(event->time < now) {
-			avl_delete(event_tree, event);
-			return event;
+	if(sig) {
+		sig->cb(sig->data);
+	}
+}
+
+static void pipe_init(void) {
+	if(!pipe(pipefd)) {
+		io_add(&signalio, signalio_handler, NULL, pipefd[0], IO_READ);
+	}
+}
+
+void signal_add(signal_t *sig, signal_cb_t cb, void *data, int signum) {
+	if(sig->cb) {
+		return;
+	}
+
+	sig->cb = cb;
+	sig->data = data;
+	sig->signum = signum;
+	sig->node.data = sig;
+
+	if(pipefd[0] == -1) {
+		pipe_init();
+	}
+
+	signal(sig->signum, signal_handler);
+
+	if(!splay_insert_node(&signal_tree, &sig->node)) {
+		abort();
+	}
+}
+
+void signal_del(signal_t *sig) {
+	if(!sig->cb) {
+		return;
+	}
+
+	signal(sig->signum, SIG_DFL);
+
+	splay_unlink_node(&signal_tree, &sig->node);
+	sig->cb = NULL;
+}
+#endif
+
+static struct timeval *get_time_remaining(struct timeval *diff) {
+	gettimeofday(&now, NULL);
+	struct timeval *tv = NULL;
+
+	while(timeout_tree.head) {
+		timeout_t *timeout = timeout_tree.head->data;
+		timersub(&timeout->tv, &now, diff);
+
+		if(diff->tv_sec < 0) {
+			timeout->cb(timeout->data);
+
+			if(timercmp(&timeout->tv, &now, <)) {
+				timeout_del(timeout);
+			}
+		} else {
+			tv = diff;
+			break;
 		}
 	}
 
-	return NULL;
+	return tv;
+}
+
+bool event_loop(void) {
+	running = true;
+
+#ifndef HAVE_MINGW
+	fd_set readable;
+	fd_set writable;
+
+	while(running) {
+		struct timeval diff;
+		struct timeval *tv = get_time_remaining(&diff);
+		memcpy(&readable, &readfds, sizeof(readable));
+		memcpy(&writable, &writefds, sizeof(writable));
+
+		int fds = 0;
+
+		if(io_tree.tail) {
+			io_t *last = io_tree.tail->data;
+			fds = last->fd + 1;
+		}
+
+		int n = select(fds, &readable, &writable, NULL, tv);
+
+		if(n < 0) {
+			if(sockwouldblock(sockerrno)) {
+				continue;
+			} else {
+				return false;
+			}
+		}
+
+		if(!n) {
+			continue;
+		}
+
+		unsigned int curgen = io_tree.generation;
+
+		for splay_each(io_t, io, &io_tree) {
+			if(FD_ISSET(io->fd, &writable)) {
+				io->cb(io->data, IO_WRITE);
+			} else if(FD_ISSET(io->fd, &readable)) {
+				io->cb(io->data, IO_READ);
+			} else {
+				continue;
+			}
+
+			/*
+			   There are scenarios in which the callback will remove another io_t from the tree
+			   (e.g. closing a double connection). Since splay_each does not support that, we
+			   need to exit the loop if that happens. That's okay, since any remaining events will
+			   get picked up by the next select() call.
+			 */
+			if(curgen != io_tree.generation) {
+				break;
+			}
+		}
+	}
+
+#else
+
+	while(running) {
+		struct timeval diff;
+		struct timeval *tv = get_time_remaining(&diff);
+		DWORD timeout_ms = tv ? (DWORD)(tv->tv_sec * 1000 + tv->tv_usec / 1000 + 1) : WSA_INFINITE;
+
+		if(!event_count) {
+			Sleep(timeout_ms);
+			continue;
+		}
+
+		/*
+		   For some reason, Microsoft decided to make the FD_WRITE event edge-triggered instead of level-triggered,
+		   which is the opposite of what select() does. In practice, that means that if a FD_WRITE event triggers,
+		   it will never trigger again until a send() returns EWOULDBLOCK. Since the semantics of this event loop
+		   is that write events are level-triggered (i.e. they continue firing until the socket is full), we need
+		   to emulate these semantics by making sure we fire each IO_WRITE that is still writeable.
+
+		   Note that technically FD_CLOSE has the same problem, but it's okay because user code does not rely on
+		   this event being fired again if ignored.
+		*/
+		unsigned int curgen = io_tree.generation;
+
+		for splay_each(io_t, io, &io_tree) {
+			if(io->flags & IO_WRITE && send(io->fd, NULL, 0, 0) == 0) {
+				io->cb(io->data, IO_WRITE);
+
+				if(curgen != io_tree.generation) {
+					break;
+				}
+			}
+		}
+
+		if(event_count > WSA_MAXIMUM_WAIT_EVENTS) {
+			WSASetLastError(WSA_INVALID_PARAMETER);
+			return(false);
+		}
+
+		WSAEVENT events[WSA_MAXIMUM_WAIT_EVENTS];
+		io_t *io_map[WSA_MAXIMUM_WAIT_EVENTS];
+		DWORD event_index = 0;
+
+		for splay_each(io_t, io, &io_tree) {
+			events[event_index] = io->event;
+			io_map[event_index] = io;
+			event_index++;
+		}
+
+		/*
+		 * If the generation number changes due to event addition
+		 * or removal by a callback we restart the loop.
+		 */
+		curgen = io_tree.generation;
+
+		for(DWORD event_offset = 0; event_offset < event_count;) {
+			DWORD result = WSAWaitForMultipleEvents(event_count - event_offset, &events[event_offset], FALSE, timeout_ms, FALSE);
+
+			if(result == WSA_WAIT_TIMEOUT) {
+				break;
+			}
+
+			if(result >= event_count - event_offset) {
+				return(false);
+			}
+
+			/* Look up io in the map by index. */
+			event_index = result - event_offset;
+			io_t *io = io_map[event_index];
+
+			if(io->fd == -1) {
+				io->cb(io->data, 0);
+
+				if(curgen != io_tree.generation) {
+					break;
+				}
+			} else {
+				WSANETWORKEVENTS network_events;
+
+				if(WSAEnumNetworkEvents(io->fd, io->event, &network_events) != 0) {
+					return(false);
+				}
+
+				if(network_events.lNetworkEvents & READ_EVENTS) {
+					io->cb(io->data, IO_READ);
+
+					if(curgen != io_tree.generation) {
+						break;
+					}
+				}
+
+				/*
+				    The fd might be available for write too. However, if we already fired the read callback, that
+				    callback might have deleted the io (e.g. through terminate_connection()), so we can't fire the
+				    write callback here. Instead, we loop back and let the writable io loop above handle it.
+				 */
+			}
+
+			/* Continue checking the rest of the events. */
+			event_offset = event_index + 1;
+
+			/* Just poll the next time through. */
+			timeout_ms = 0;
+		}
+	}
+
+#endif
+
+	return true;
+}
+
+void event_exit(void) {
+	running = false;
 }