X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_socket.c;h=767e91e92b30ba92d1af9ded372760ed2647ce72;hp=a39c2d2813f8532e32634ca01907cbf53fd3c8ee;hb=cef40b8b978694fc0e7c02e292fcbb60806bf028;hpb=ff306f0cdaedb50de1472e7c1fb55de922a6ca60

diff --git a/src/net_socket.c b/src/net_socket.c
index a39c2d28..767e91e9 100644
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -1,7 +1,7 @@
 /*
     net_socket.c -- Handle various kinds of sockets.
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2012 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2014 Guus Sliepen <guus@tinc-vpn.org>
                   2006      Scott Lamb <slamb@slamb.org>
                   2009      Florian Forster <octo@verplant.org>
 
@@ -24,8 +24,11 @@
 
 #include "conf.h"
 #include "connection.h"
+#include "control_common.h"
+#include "list.h"
 #include "logger.h"
 #include "meta.h"
+#include "names.h"
 #include "net.h"
 #include "netutl.h"
 #include "protocol.h"
@@ -40,11 +43,15 @@
 int addressfamily = AF_UNSPEC;
 int maxtimeout = 900;
 int seconds_till_retry = 5;
-int udp_rcvbuf = 0;
-int udp_sndbuf = 0;
+int udp_rcvbuf = 1024 * 1024;
+int udp_sndbuf = 1024 * 1024;
+int max_connection_burst = 100;
 
 listen_socket_t listen_socket[MAXSOCKETS];
 int listen_sockets;
+#ifndef HAVE_MINGW
+io_t unix_socket;
+#endif
 list_t *outgoing_list = NULL;
 
 /* Setup sockets */
@@ -62,7 +69,7 @@ static void configure_tcp(connection_t *c) {
 	unsigned long arg = 1;
 
 	if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
-		logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %s", c->hostname, sockstrerror(sockerrno));
 	}
 #endif
 
@@ -96,7 +103,7 @@ static bool bind_to_interface(int sd) {
 	status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
 	if(status) {
 		logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
-				strerror(errno));
+				sockstrerror(sockerrno));
 		return false;
 	}
 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
@@ -106,6 +113,34 @@ static bool bind_to_interface(int sd) {
 	return true;
 }
 
+static bool bind_to_address(connection_t *c) {
+	int s = -1;
+
+	for(int i = 0; i < listen_sockets && listen_socket[i].bindto; i++) {
+		if(listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family)
+			continue;
+		if(s >= 0)
+			return false;
+		s = i;
+	}
+
+	if(s < 0)
+		return false;
+
+	sockaddr_t sa = listen_socket[s].sa;
+	if(sa.sa.sa_family == AF_INET)
+		sa.in.sin_port = 0;
+	else if(sa.sa.sa_family == AF_INET6)
+		sa.in6.sin6_port = 0;
+
+	if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
+		logger(DEBUG_CONNECTIONS, LOG_WARNING, "Can't bind outgoing socket: %s", sockstrerror(sockerrno));
+		return false;
+	}
+
+	return true;
+}
+
 int setup_listen_socket(const sockaddr_t *sa) {
 	int nfd;
 	char *addrstr;
@@ -144,7 +179,7 @@ int setup_listen_socket(const sockaddr_t *sa) {
 		if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
 			closesocket(nfd);
 			logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
-				   strerror(sockerrno));
+				   sockstrerror(sockerrno));
 			return -1;
 		}
 #else
@@ -212,10 +247,10 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 	setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
 
 	if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
-		logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, sockstrerror(sockerrno));
 
 	if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
-		logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, sockstrerror(sockerrno));
 
 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
 	if(sa->sa.sa_family == AF_INET6)
@@ -236,8 +271,6 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 		option = 1;
 		setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 	}
-#else
-#warning No way to disable IPv4 fragmentation
 #endif
 
 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
@@ -250,8 +283,6 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 		option = 1;
 		setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 	}
-#else
-#warning No way to disable IPv6 fragmentation
 #endif
 
 	if (!bind_to_interface(nfd)) {
@@ -270,7 +301,7 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 	return nfd;
 } /* int setup_vpn_in_socket */
 
-static void retry_outgoing_handler(int fd, short events, void *data) {
+static void retry_outgoing_handler(void *data) {
 	setup_outgoing_connection(data);
 }
 
@@ -280,21 +311,15 @@ void retry_outgoing(outgoing_t *outgoing) {
 	if(outgoing->timeout > maxtimeout)
 		outgoing->timeout = maxtimeout;
 
-	timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
-	event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
+	timeout_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval){outgoing->timeout, rand() % 100000});
 
-	logger(DEBUG_CONNECTIONS, LOG_NOTICE,
-			   "Trying to re-establish outgoing connection in %d seconds",
-			   outgoing->timeout);
+	logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 }
 
 void finish_connecting(connection_t *c) {
 	logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 
-	if(proxytype != PROXY_EXEC)
-		configure_tcp(c);
-
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 	c->status.connecting = false;
 
 	send_id(c);
@@ -305,7 +330,7 @@ static void do_outgoing_pipe(connection_t *c, char *command) {
 	int fd[2];
 
 	if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
-		logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", sockstrerror(sockerrno));
 		return;
 	}
 
@@ -348,29 +373,73 @@ static void do_outgoing_pipe(connection_t *c, char *command) {
 #endif
 }
 
-static void handle_meta_write(int sock, short events, void *data) {
-	connection_t *c = data;
+static void handle_meta_write(connection_t *c) {
+	if(c->outbuf.len <= c->outbuf.offset)
+		return;
 
 	ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
 	if(outlen <= 0) {
-		if(!errno || errno == EPIPE) {
+		if(!sockerrno || sockerrno == EPIPE) {
 			logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 		} else if(sockwouldblock(sockerrno)) {
 			logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 			return;
 		} else {
-			logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not send %d bytes of data to %s (%s): %s", c->outbuf.len - c->outbuf.offset, c->name, c->hostname, strerror(errno));
+			logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not send %d bytes of data to %s (%s): %s", c->outbuf.len - c->outbuf.offset, c->name, c->hostname, sockstrerror(sockerrno));
 		}
 
-		terminate_connection(c, c->status.active);
+		terminate_connection(c, c->edge);
 		return;
 	}
 
 	buffer_read(&c->outbuf, outlen);
-	if(!c->outbuf.len && event_initialized(&c->outevent))
-		event_del(&c->outevent);
+	if(!c->outbuf.len)
+		io_set(&c->io, IO_READ);
 }
 
+static void handle_meta_io(void *data, int flags) {
+	connection_t *c = data;
+
+	if(c->status.connecting) {
+		/*
+		   The event loop does not protect against spurious events. Verify that we are actually connected
+		   by issuing an empty send() call.
+
+		   Note that the behavior of send() on potentially unconnected sockets differ between platforms:
+		   +------------+-----------+-------------+-----------+
+		   |   Event    |   POSIX   |    Linux    |  Windows  |
+		   +------------+-----------+-------------+-----------+
+		   | Spurious   | ENOTCONN  | EWOULDBLOCK | ENOTCONN  |
+		   | Failed     | ENOTCONN  | (cause)     | ENOTCONN  |
+		   | Successful | (success) | (success)   | (success) |
+		   +------------+-----------+-------------+-----------+
+		*/
+		if (send(c->socket, NULL, 0, 0) != 0) {
+			if (sockwouldblock(sockerrno))
+				return;
+			int socket_error;
+			if (!socknotconn(sockerrno))
+				socket_error = sockerrno;
+			else {
+				socklen_t len = sizeof socket_error;
+				getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&socket_error, &len);
+			}
+			if (socket_error) {
+				logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(socket_error));
+				terminate_connection(c, false);
+			}
+			return;
+		}
+
+		c->status.connecting = false;
+		finish_connecting(c);
+	}
+
+	if(flags & IO_WRITE)
+		handle_meta_write(c);
+	else
+		handle_meta_connection_data(c);
+}
 
 bool do_outgoing_connection(outgoing_t *outgoing) {
 	char *address, *port, *space;
@@ -434,6 +503,7 @@ begin:
 		}
 		logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
 		c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
+		configure_tcp(c);
 	}
 
 	if(c->socket == -1) {
@@ -454,6 +524,7 @@ begin:
 #endif
 
 		bind_to_interface(c->socket);
+		bind_to_address(c);
 	}
 
 	/* Connect */
@@ -478,32 +549,67 @@ begin:
 
 	c->status.connecting = true;
 	c->name = xstrdup(outgoing->name);
+#ifndef DISABLE_LEGACY
 	c->outcipher = myself->connection->outcipher;
 	c->outdigest = myself->connection->outdigest;
+#endif
 	c->outmaclength = myself->connection->outmaclength;
 	c->outcompression = myself->connection->outcompression;
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 
 	connection_add(c);
 
-	event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
-	event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
-	event_add(&c->inevent, NULL);
+	io_add(&c->io, handle_meta_io, c, c->socket, IO_READ|IO_WRITE);
 
 	return true;
 }
 
+// Find edges pointing to this node, and use them to build a list of unique, known addresses.
+static struct addrinfo *get_known_addresses(node_t *n) {
+	struct addrinfo *ai = NULL;
+
+	for splay_each(edge_t, e, n->edge_tree) {
+		if(!e->reverse)
+			continue;
+
+		bool found = false;
+		for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
+			if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
+				found = true;
+				break;
+			}
+		}
+		if(found)
+			continue;
+
+		struct addrinfo *nai = xzalloc(sizeof *nai);
+		if(ai)
+			ai->ai_next = nai;
+		ai = nai;
+		ai->ai_family = e->reverse->address.sa.sa_family;
+		ai->ai_socktype = SOCK_STREAM;
+		ai->ai_protocol = IPPROTO_TCP;
+		ai->ai_addrlen = SALEN(e->reverse->address.sa);
+		ai->ai_addr = xmalloc(ai->ai_addrlen);
+		memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
+	}
+
+	return ai;
+}
+
 void setup_outgoing_connection(outgoing_t *outgoing) {
-	if(event_initialized(&outgoing->ev))
-		event_del(&outgoing->ev);
+	timeout_del(&outgoing->ev);
 
 	node_t *n = lookup_node(outgoing->name);
 
 	if(n && n->connection) {
 		logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
-
-		n->connection->outgoing = outgoing;
-		return;
+		if(!n->connection->outgoing) {
+			n->connection->outgoing = outgoing;
+			return;
+		} else {
+			goto remove;
+		}
 	}
 
 	init_configuration(&outgoing->config_tree);
@@ -511,24 +617,33 @@ void setup_outgoing_connection(outgoing_t *outgoing) {
 	outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
 
 	if(!outgoing->cfg) {
-		logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", outgoing->name);
-		return;
+		if(n)
+			outgoing->aip = outgoing->ai = get_known_addresses(n);
+		if(!outgoing->ai) {
+			logger(DEBUG_ALWAYS, LOG_DEBUG, "No address known for %s", outgoing->name);
+			goto remove;
+		}
 	}
 
 	do_outgoing_connection(outgoing);
+	return;
+
+remove:
+	list_delete(outgoing_list, outgoing);
 }
 
 /*
   accept a new tcp connect and create a
   new connection
 */
-void handle_new_meta_connection(int sock, short events, void *data) {
+void handle_new_meta_connection(void *data, int flags) {
+	listen_socket_t *l = data;
 	connection_t *c;
 	sockaddr_t sa;
 	int fd;
 	socklen_t len = sizeof sa;
 
-	fd = accept(sock, &sa.sa, &len);
+	fd = accept(l->tcp.fd, &sa.sa, &len);
 
 	if(fd < 0) {
 		logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
@@ -537,24 +652,75 @@ void handle_new_meta_connection(int sock, short events, void *data) {
 
 	sockaddrunmap(&sa);
 
+	// Check if we get many connections from the same host
+
+	static sockaddr_t prev_sa;
+	static int tarpit = -1;
+
+	if(tarpit >= 0) {
+		closesocket(tarpit);
+		tarpit = -1;
+	}
+
+	if(!sockaddrcmp_noport(&sa, &prev_sa)) {
+		static int samehost_burst;
+		static int samehost_burst_time;
+
+		if(now.tv_sec - samehost_burst_time > samehost_burst)
+			samehost_burst = 0;
+		else
+			samehost_burst -= now.tv_sec - samehost_burst_time;
+
+		samehost_burst_time = now.tv_sec;
+		samehost_burst++;
+
+		if(samehost_burst > max_connection_burst) {
+			tarpit = fd;
+			return;
+		}
+	}
+
+	memcpy(&prev_sa, &sa, sizeof sa);
+
+	// Check if we get many connections from different hosts
+
+	static int connection_burst;
+	static int connection_burst_time;
+
+	if(now.tv_sec - connection_burst_time > connection_burst)
+		connection_burst = 0;
+	else
+		connection_burst -= now.tv_sec - connection_burst_time;
+
+	connection_burst_time = now.tv_sec;
+	connection_burst++;
+
+	if(connection_burst >= max_connection_burst) {
+		connection_burst = max_connection_burst;
+		tarpit = fd;
+		return;
+	}
+
+	// Accept the new connection
+
 	c = new_connection();
 	c->name = xstrdup("<unknown>");
+#ifndef DISABLE_LEGACY
 	c->outcipher = myself->connection->outcipher;
 	c->outdigest = myself->connection->outdigest;
+#endif
 	c->outmaclength = myself->connection->outmaclength;
 	c->outcompression = myself->connection->outcompression;
 
 	c->address = sa;
 	c->hostname = sockaddr2hostname(&sa);
 	c->socket = fd;
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 
 	logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 
-	event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
-	event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
-	event_add(&c->inevent, NULL);
-		
+	io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
+
 	configure_tcp(c);
 
 	connection_add(c);
@@ -563,13 +729,54 @@ void handle_new_meta_connection(int sock, short events, void *data) {
 	send_id(c);
 }
 
+#ifndef HAVE_MINGW
+/*
+  accept a new UNIX socket connection
+*/
+void handle_new_unix_connection(void *data, int flags) {
+	io_t *io = data;
+	connection_t *c;
+	sockaddr_t sa;
+	int fd;
+	socklen_t len = sizeof sa;
+
+	fd = accept(io->fd, &sa.sa, &len);
+
+	if(fd < 0) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
+		return;
+	}
+
+	sockaddrunmap(&sa);
+
+	c = new_connection();
+	c->name = xstrdup("<control>");
+	c->address = sa;
+	c->hostname = xstrdup("localhost port unix");
+	c->socket = fd;
+	c->last_ping_time = now.tv_sec;
+
+	logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
+
+	io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
+
+	connection_add(c);
+
+	c->allow_request = ID;
+
+	send_id(c);
+}
+#endif
+
 static void free_outgoing(outgoing_t *outgoing) {
-	if(event_initialized(&outgoing->ev))
-		event_del(&outgoing->ev);
+	timeout_del(&outgoing->ev);
 
 	if(outgoing->ai)
 		freeaddrinfo(outgoing->ai);
 
+	if(outgoing->config_tree)
+		exit_configuration(&outgoing->config_tree);
+
 	if(outgoing->name)
 		free(outgoing->name);
 
@@ -577,24 +784,19 @@ static void free_outgoing(outgoing_t *outgoing) {
 }
 
 void try_outgoing_connections(void) {
-	static config_t *cfg = NULL;
-	char *name;
-	outgoing_t *outgoing;
-	
 	/* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 
 	if(!outgoing_list) {
 		outgoing_list = list_alloc((list_action_t)free_outgoing);
 	} else {
-		for(list_node_t *i = outgoing_list->head; i; i = i->next) {
-			outgoing = i->data;
+		for list_each(outgoing_t, outgoing, outgoing_list)
 			outgoing->timeout = -1;
-		}
 	}
 
 	/* Make sure there is one outgoing_t in the list for each ConnectTo. */
 
-	for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
+	for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
+		char *name;
 		get_config_string(cfg, &name);
 
 		if(!check_id(name)) {
@@ -605,10 +807,14 @@ void try_outgoing_connections(void) {
 			continue;
 		}
 
+		if(!strcmp(name, myself->name)) {
+			free(name);
+			continue;
+		}
+
 		bool found = false;
 
-		for(list_node_t *i = outgoing_list->head; i; i = i->next) {
-			outgoing = i->data;
+		for list_each(outgoing_t, outgoing, outgoing_list) {
 			if(!strcmp(outgoing->name, name)) {
 				found = true;
 				outgoing->timeout = 0;
@@ -617,7 +823,7 @@ void try_outgoing_connections(void) {
 		}
 
 		if(!found) {
-			outgoing = xmalloc_and_zero(sizeof *outgoing);
+			outgoing_t *outgoing = xzalloc(sizeof *outgoing);
 			outgoing->name = name;
 			list_insert_tail(outgoing_list, outgoing);
 			setup_outgoing_connection(outgoing);
@@ -626,22 +832,17 @@ void try_outgoing_connections(void) {
 
 	/* Terminate any connections whose outgoing_t is to be deleted. */
 
-	for(list_node_t *node = connection_list->head, *next; node; node = next) {
-		next = node->next;
-		connection_t *c = node->data;
+	for list_each(connection_t, c, connection_list) {
 		if(c->outgoing && c->outgoing->timeout == -1) {
 			c->outgoing = NULL;
 			logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
-			terminate_connection(c, c->status.active);
+			terminate_connection(c, c->edge);
 		}
 	}
 
 	/* Delete outgoing_ts for which there is no ConnectTo. */
 
-	for(list_node_t *node = outgoing_list->head, *next; node; node = next) {
-		next = node->next;
-		outgoing = node->data;
+	for list_each(outgoing_t, outgoing, outgoing_list)
 		if(outgoing->timeout == -1)
 			list_delete_node(outgoing_list, node);
-	}
 }