X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_socket.c;h=ab3c17e02a110b41d9044cdc25c15c3c74ca4a0b;hp=0b9a13248ece76c252a59f3468e7e4eafce3b4e6;hb=796c14b75c9e8066b4f68f6ce7cdaddd97c46a87;hpb=67d9a72ea2f10f1a2d2eb7c04a41183359d5e1cc

diff --git a/src/net_socket.c b/src/net_socket.c
index 0b9a1324..ab3c17e0 100644
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -1,7 +1,9 @@
 /*
     net_socket.c -- Handle various kinds of sockets.
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2007 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2013 Guus Sliepen <guus@tinc-vpn.org>
+                  2006      Scott Lamb <slamb@slamb.org>
+                  2009      Florian Forster <octo@verplant.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
@@ -13,30 +15,26 @@
     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 "splay_tree.h"
 #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"
 #include "utils.h"
 #include "xalloc.h"
 
-#ifdef WSAEINPROGRESS
-#define EINPROGRESS WSAEINPROGRESS
-#endif
-
 /* Needed on Mac OS/X */
 #ifndef SOL_TCP
 #define SOL_TCP IPPROTO_TCP
@@ -45,9 +43,16 @@
 int addressfamily = AF_UNSPEC;
 int maxtimeout = 900;
 int seconds_till_retry = 5;
+int udp_rcvbuf = 0;
+int udp_sndbuf = 0;
+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 */
 
@@ -58,25 +63,82 @@ static void configure_tcp(connection_t *c) {
 	int flags = fcntl(c->socket, F_GETFL);
 
 	if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
-		logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
 	}
 #elif defined(WIN32)
 	unsigned long arg = 1;
 
 	if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
-		logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
+		logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %s", c->hostname, sockstrerror(sockerrno));
 	}
 #endif
 
 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 	option = 1;
-	setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
+	setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof option);
 #endif
 
 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
 	option = IPTOS_LOWDELAY;
-	setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
+	setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof option);
+#endif
+}
+
+static bool bind_to_interface(int sd) {
+	char *iface;
+
+#if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
+	struct ifreq ifr;
+	int status;
+#endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
+
+	if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
+		return true;
+
+#if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
+	memset(&ifr, 0, sizeof(ifr));
+	strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
+	ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
+
+	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));
+		return false;
+	}
+#else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
+	logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 #endif
+
+	return true;
+}
+
+static bool bind_to_address(connection_t *c) {
+	int s = -1;
+
+	for(int i = 0; i < listen_sockets; 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", strerror(errno));
+		return false;
+	}
+
+	return true;
 }
 
 int setup_listen_socket(const sockaddr_t *sa) {
@@ -85,52 +147,57 @@ int setup_listen_socket(const sockaddr_t *sa) {
 	int option;
 	char *iface;
 
-	cp();
-
 	nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 
 	if(nfd < 0) {
-		ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
+		logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 		return -1;
 	}
 
+#ifdef FD_CLOEXEC
+	fcntl(nfd, F_SETFD, FD_CLOEXEC);
+#endif
+
 	/* Optimize TCP settings */
 
 	option = 1;
-	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
+	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
+
+#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
+	if(sa->sa.sa_family == AF_INET6)
+		setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
+#endif
 
 	if(get_config_string
 	   (lookup_config(config_tree, "BindToInterface"), &iface)) {
 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 		struct ifreq ifr;
 
-		memset(&ifr, 0, sizeof(ifr));
+		memset(&ifr, 0, sizeof ifr);
 		strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 
-		if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
+		if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
 			closesocket(nfd);
-			logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
-				   strerror(errno));
+			logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
+				   strerror(sockerrno));
 			return -1;
 		}
 #else
-		logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
+		logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 #endif
 	}
 
 	if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 		closesocket(nfd);
 		addrstr = sockaddr2hostname(sa);
-		logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
-			   strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 		free(addrstr);
 		return -1;
 	}
 
 	if(listen(nfd, 3)) {
 		closesocket(nfd);
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
-			   strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 		return -1;
 	}
 
@@ -142,22 +209,24 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 	char *addrstr;
 	int option;
 
-	cp();
-
 	nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 
 	if(nfd < 0) {
-		logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 		return -1;
 	}
 
+#ifdef FD_CLOEXEC
+	fcntl(nfd, F_SETFD, FD_CLOEXEC);
+#endif
+
 #ifdef O_NONBLOCK
 	{
 		int flags = fcntl(nfd, F_GETFL);
 
 		if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 			closesocket(nfd);
-			logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
+			logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 				   strerror(errno));
 			return -1;
 		}
@@ -167,328 +236,547 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 		unsigned long arg = 1;
 		if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 			closesocket(nfd);
-			logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
-				WSAGetLastError());
+			logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 			return -1;
 		}
 	}
 #endif
 
 	option = 1;
-	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
+	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
+	setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
 
-#if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
-	{
-		bool choice;
+	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));
 
-		if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
-			option = IP_PMTUDISC_DO;
-			setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
-		}
-	}
+	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));
+
+#if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
+	if(sa->sa.sa_family == AF_INET6)
+		setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 #endif
 
-#if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
-	{
-		bool choice;
+#if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
+#define IP_DONTFRAGMENT IP_DONTFRAG
+#endif
 
-		if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
-			option = IPV6_PMTUDISC_DO;
-			setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
-		}
+#if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
+	if(myself->options & OPTION_PMTU_DISCOVERY) {
+		option = IP_PMTUDISC_DO;
+		setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 	}
+#elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
+	if(myself->options & OPTION_PMTU_DISCOVERY) {
+		option = 1;
+		setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
+	}
+#else
+#warning No way to disable IPv4 fragmentation
 #endif
 
-#if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
-	{
-		char *iface;
-		struct ifreq ifr;
-
-		if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
-			memset(&ifr, 0, sizeof(ifr));
-			strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
-
-			if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
-				closesocket(nfd);
-				logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
-					   strerror(errno));
-				return -1;
-			}
-		}
+#if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
+	if(myself->options & OPTION_PMTU_DISCOVERY) {
+		option = IPV6_PMTUDISC_DO;
+		setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
+	}
+#elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
+	if(myself->options & OPTION_PMTU_DISCOVERY) {
+		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)) {
+		closesocket(nfd);
+		return -1;
+	}
+
 	if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 		closesocket(nfd);
 		addrstr = sockaddr2hostname(sa);
-		logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
-			   strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 		free(addrstr);
 		return -1;
 	}
 
 	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);
 }
 
 void retry_outgoing(outgoing_t *outgoing) {
-	cp();
-
 	outgoing->timeout += 5;
 
 	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});
 
-	ifdebug(CONNECTIONS) logger(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) {
-	cp();
-
-	ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
+	logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 
-	configure_tcp(c);
-
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 	c->status.connecting = false;
 
 	send_id(c);
 }
 
-void do_outgoing_connection(connection_t *c) {
-	char *address, *port;
-	int result;
+static void do_outgoing_pipe(connection_t *c, char *command) {
+#ifndef HAVE_MINGW
+	int fd[2];
 
-	cp();
+	if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
+		return;
+	}
 
-begin:
-	if(!c->outgoing->ai) {
-		if(!c->outgoing->cfg) {
-			ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
-					   c->name);
-			retry_outgoing(c->outgoing);
-			c->outgoing = NULL;
-			connection_del(c);
+	if(fork()) {
+		c->socket = fd[0];
+		close(fd[1]);
+		logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
+		return;
+	}
+
+	close(0);
+	close(1);
+	close(fd[0]);
+	dup2(fd[1], 0);
+	dup2(fd[1], 1);
+	close(fd[1]);
+
+	// Other filedescriptors should be closed automatically by CLOEXEC
+
+	char *host = NULL;
+	char *port = NULL;
+
+	sockaddr2str(&c->address, &host, &port);
+	setenv("REMOTEADDRESS", host, true);
+	setenv("REMOTEPORT", port, true);
+	setenv("NODE", c->name, true);
+	setenv("NAME", myself->name, true);
+	if(netname)
+		setenv("NETNAME", netname, true);
+
+	int result = system(command);
+	if(result < 0)
+		logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
+	else if(result)
+		logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
+	exit(result);
+#else
+	logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
+	return;
+#endif
+}
+
+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) {
+			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));
+		}
+
+		terminate_connection(c, c->status.active);
+		return;
+	}
+
+	buffer_read(&c->outbuf, outlen);
+	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) {
+		c->status.connecting = false;
+
+		int result;
+		socklen_t len = sizeof result;
+		getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
+
+		if(!result)
+			finish_connecting(c);
+		else {
+			logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(result));
+			terminate_connection(c, false);
 			return;
 		}
+	}
+
+	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;
+	struct addrinfo *proxyai = NULL;
+	int result;
+
+begin:
+	if(!outgoing->ai) {
+		if(!outgoing->cfg) {
+			logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
+			retry_outgoing(outgoing);
+			return false;
+		}
 
-		get_config_string(c->outgoing->cfg, &address);
+		get_config_string(outgoing->cfg, &address);
 
-		if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
-			asprintf(&port, "655");
+		space = strchr(address, ' ');
+		if(space) {
+			port = xstrdup(space + 1);
+			*space = 0;
+		} else {
+			if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
+				port = xstrdup("655");
+		}
 
-		c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
+		outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 		free(address);
 		free(port);
 
-		c->outgoing->aip = c->outgoing->ai;
-		c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
+		outgoing->aip = outgoing->ai;
+		outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
 	}
 
-	if(!c->outgoing->aip) {
-		freeaddrinfo(c->outgoing->ai);
-		c->outgoing->ai = NULL;
+	if(!outgoing->aip) {
+		if(outgoing->ai)
+			freeaddrinfo(outgoing->ai);
+		outgoing->ai = NULL;
 		goto begin;
 	}
 
-	memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
-	c->outgoing->aip = c->outgoing->aip->ai_next;
+	connection_t *c = new_connection();
+	c->outgoing = outgoing;
 
-	if(c->hostname)
-		free(c->hostname);
+	memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
+	outgoing->aip = outgoing->aip->ai_next;
 
 	c->hostname = sockaddr2hostname(&c->address);
 
-	ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
-			   c->hostname);
-
-	c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+	logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
+
+	if(!proxytype) {
+		c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+		configure_tcp(c);
+	} else if(proxytype == PROXY_EXEC) {
+		do_outgoing_pipe(c, proxyhost);
+	} else {
+		proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
+		if(!proxyai) {
+			free_connection(c);
+			goto 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) {
-		ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
-				   strerror(errno));
-
+		logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
+		free_connection(c);
 		goto begin;
 	}
 
-	/* Optimize TCP settings */
-
-	configure_tcp(c);
+#ifdef FD_CLOEXEC
+	fcntl(c->socket, F_SETFD, FD_CLOEXEC);
+#endif
 
-	/* Connect */
+	if(proxytype != PROXY_EXEC) {
+#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
+		int option = 1;
+		if(c->address.sa.sa_family == AF_INET6)
+			setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
+#endif
 
-	result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
+		bind_to_interface(c->socket);
+		bind_to_address(c);
+	}
 
-	if(result == -1) {
-		if(errno == EINPROGRESS
-#if defined(WIN32) && !defined(O_NONBLOCK)
-		   || WSAGetLastError() == WSAEWOULDBLOCK
-#endif
-		) {
-			c->status.connecting = true;
-			return;
-		}
+	/* Connect */
 
-		closesocket(c->socket);
+	if(!proxytype) {
+		result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
+	} else if(proxytype == PROXY_EXEC) {
+		result = 0;
+	} else {
+		result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
+		freeaddrinfo(proxyai);
+	}
 
-		ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
+	if(result == -1 && !sockinprogress(sockerrno)) {
+		logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
+		free_connection(c);
 
 		goto begin;
 	}
 
-	finish_connecting(c);
+	/* Now that there is a working socket, fill in the rest and register this connection. */
 
-	return;
-}
+	c->status.connecting = true;
+	c->name = xstrdup(outgoing->name);
+	c->outcipher = myself->connection->outcipher;
+	c->outdigest = myself->connection->outdigest;
+	c->outmaclength = myself->connection->outmaclength;
+	c->outcompression = myself->connection->outcompression;
+	c->last_ping_time = now.tv_sec;
 
-void handle_meta_read(struct bufferevent *event, void *data) {
-	logger(LOG_EMERG, _("handle_meta_read() called"));
-	abort();
-}
+	connection_add(c);
 
-void handle_meta_write(struct bufferevent *event, void *data) {
-	logger(LOG_DEBUG, _("handle_meta_write() called"));
-}
+	io_add(&c->io, handle_meta_io, c, c->socket, IO_READ|IO_WRITE);
 
-void handle_meta_connection_error(struct bufferevent *event, short what, void *data) {
-	connection_t *c = data;
-	logger(LOG_EMERG, _("handle_meta_connection_error() called: %d: %s"), what, strerror(errno));
-	terminate_connection(c, c->status.active);
+	return true;
 }
 
 void setup_outgoing_connection(outgoing_t *outgoing) {
+	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;
+	}
+
+	init_configuration(&outgoing->config_tree);
+	read_host_config(outgoing->config_tree, outgoing->name);
+	outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
+
+	if(!outgoing->cfg) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", outgoing->name);
+		return;
+	}
+
+	do_outgoing_connection(outgoing);
+}
+
+/*
+  accept a new tcp connect and create a
+  new connection
+*/
+void handle_new_meta_connection(void *data, int flags) {
+	listen_socket_t *l = data;
 	connection_t *c;
-	node_t *n;
+	sockaddr_t sa;
+	int fd;
+	socklen_t len = sizeof sa;
+
+	fd = accept(l->tcp.fd, &sa.sa, &len);
+
+	if(fd < 0) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
+		return;
+	}
+
+	sockaddrunmap(&sa);
+
+	// Check if we get many connections from the same host
+
+	static sockaddr_t prev_sa;
+	static time_t prev_time;
+	static int tarpit = -1;
+
+	if(tarpit >= 0) {
+		closesocket(tarpit);
+		tarpit = -1;
+	}
 
-	cp();
+	if(!sockaddrcmp_noport(&sa, &prev_sa)) {
+		static int samehost_burst;
+		static int samehost_burst_time;
 
-	n = lookup_node(outgoing->name);
+		if(now.tv_sec - samehost_burst_time > samehost_burst)
+			samehost_burst = 0;
+		else
+			samehost_burst -= now.tv_sec - samehost_burst_time;
 
-	if(n)
-		if(n->connection) {
-			ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
+		samehost_burst_time = now.tv_sec;
+		samehost_burst++;
 
-			n->connection->outgoing = outgoing;
+		if(samehost_burst > max_connection_burst) {
+			tarpit = fd;
 			return;
 		}
+	}
+
+	memcpy(&prev_sa, &sa, sizeof sa);
+	prev_time = now.tv_sec;
+
+	// 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(outgoing->name);
+	c->name = xstrdup("<unknown>");
 	c->outcipher = myself->connection->outcipher;
 	c->outdigest = myself->connection->outdigest;
 	c->outmaclength = myself->connection->outmaclength;
 	c->outcompression = myself->connection->outcompression;
 
-	init_configuration(&c->config_tree);
-	read_connection_config(c);
+	c->address = sa;
+	c->hostname = sockaddr2hostname(&sa);
+	c->socket = fd;
+	c->last_ping_time = now.tv_sec;
 
-	outgoing->cfg = lookup_config(c->config_tree, "Address");
+	logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 
-	if(!outgoing->cfg) {
-		logger(LOG_ERR, _("No address specified for %s"), c->name);
-		free_connection(c);
-		free(outgoing->name);
-		free(outgoing);
-		return;
-	}
+	io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 
-	c->outgoing = outgoing;
-	c->last_ping_time = time(NULL);
+	configure_tcp(c);
 
 	connection_add(c);
 
-	do_outgoing_connection(c);
-
-	event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
-	event_add(&c->inevent, NULL);
-	c->buffer = bufferevent_new(c->socket, handle_meta_read, handle_meta_write, handle_meta_connection_error, c);
-	if(!c->buffer) {
-		logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
-		abort();
-	}
-	bufferevent_disable(c->buffer, EV_READ);
+	c->allow_request = ID;
+	send_id(c);
 }
 
+#ifndef HAVE_MINGW
 /*
-  accept a new tcp connect and create a
-  new connection
+  accept a new UNIX socket connection
 */
-void handle_new_meta_connection(int sock, short events, void *data) {
+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);
-
-	cp();
+	socklen_t len = sizeof sa;
 
-	fd = accept(sock, &sa.sa, &len);
+	fd = accept(io->fd, &sa.sa, &len);
 
 	if(fd < 0) {
-		logger(LOG_ERR, _("Accepting a new connection failed: %s"), strerror(errno));
+		logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 		return;
 	}
 
 	sockaddrunmap(&sa);
 
 	c = new_connection();
-	c->name = xstrdup("<unknown>");
-	c->outcipher = myself->connection->outcipher;
-	c->outdigest = myself->connection->outdigest;
-	c->outmaclength = myself->connection->outmaclength;
-	c->outcompression = myself->connection->outcompression;
-
+	c->name = xstrdup("<control>");
 	c->address = sa;
-	c->hostname = sockaddr2hostname(&sa);
+	c->hostname = xstrdup("localhost port unix");
 	c->socket = fd;
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 
-	ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
+	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_add(&c->inevent, NULL);
-	c->buffer = bufferevent_new(c->socket, NULL, handle_meta_write, handle_meta_connection_error, c);
-	if(!c->buffer) {
-		logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
-		abort();
-	}
-	bufferevent_disable(c->buffer, EV_READ);
-		
-	configure_tcp(c);
+	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) {
+	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);
+
+	free(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. */
 
-	cp();
+	if(!outgoing_list) {
+		outgoing_list = list_alloc((list_action_t)free_outgoing);
+	} else {
+		for list_each(outgoing_t, outgoing, outgoing_list)
+			outgoing->timeout = -1;
+	}
 
-	for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
+	/* Make sure there is one outgoing_t in the list for each ConnectTo. */
+
+	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)) {
-			logger(LOG_ERR,
-				   _("Invalid name for outgoing connection in %s line %d"),
+			logger(DEBUG_ALWAYS, LOG_ERR,
+				   "Invalid name for outgoing connection in %s line %d",
 				   cfg->file, cfg->line);
 			free(name);
 			continue;
 		}
 
-		outgoing = xmalloc_and_zero(sizeof(*outgoing));
-		outgoing->name = name;
-		setup_outgoing_connection(outgoing);
+		bool found = false;
+
+		for list_each(outgoing_t, outgoing, outgoing_list) {
+			if(!strcmp(outgoing->name, name)) {
+				found = true;
+				outgoing->timeout = 0;
+				break;
+			}
+		}
+
+		if(!found) {
+			outgoing_t *outgoing = xzalloc(sizeof *outgoing);
+			outgoing->name = name;
+			list_insert_tail(outgoing_list, outgoing);
+			setup_outgoing_connection(outgoing);
+		}
 	}
+
+	/* Terminate any connections whose outgoing_t is to be deleted. */
+
+	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);
+		}
+	}
+
+	/* Delete outgoing_ts for which there is no ConnectTo. */
+
+	for list_each(outgoing_t, outgoing, outgoing_list)
+		if(outgoing->timeout == -1)
+			list_delete_node(outgoing_list, node);
 }