X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fnet_socket.c;h=a1dfcd3552cec4b2545313f03a9b32d70035cb08;hb=92283d7342fabd882126a892b2636d57ff0458de;hp=78e1ad2c2703f945260f517af236551fa70f3a95;hpb=721e4caee0f7c6e003c297c95fb6d93bd4102219;p=meshlink

diff --git a/src/net_socket.c b/src/net_socket.c
index 78e1ad2c..ea5fdaa0 100644
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -1,7 +1,6 @@
 /*
     net_socket.c -- Handle various kinds of sockets.
-    Copyright (C) 1998-2003 Ivo Timmermans <ivo@o2w.nl>,
-                  2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+    Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
 
     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
@@ -13,20 +12,18 @@
     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: net_socket.c,v 1.1.2.33 2003/07/29 22:59:00 guus Exp $
+    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 "conf.h"
 #include "connection.h"
-#include "event.h"
+#include "list.h"
 #include "logger.h"
+#include "meshlink_internal.h"
 #include "meta.h"
 #include "net.h"
 #include "netutl.h"
@@ -34,402 +31,796 @@
 #include "utils.h"
 #include "xalloc.h"
 
-#ifdef WSAEINPROGRESS
-#define EINPROGRESS WSAEINPROGRESS
+/* Needed on Mac OS/X */
+#ifndef SOL_TCP
+#define SOL_TCP IPPROTO_TCP
+#endif
+
+#ifndef MSG_NOSIGNAL
+#define MSG_NOSIGNAL 0
 #endif
 
 int addressfamily = AF_UNSPEC;
-int maxtimeout = 900;
 int seconds_till_retry = 5;
-
-listen_socket_t listen_socket[MAXSOCKETS];
-int listen_sockets;
+int max_connection_burst = 100;
 
 /* Setup sockets */
 
-int setup_listen_socket(const sockaddr_t *sa)
-{
-	int nfd, flags;
-	char *addrstr;
-	int option;
-	char *iface;
-#ifdef SO_BINDTODEVICE
-	struct ifreq ifr;
+static void configure_tcp(connection_t *c) {
+#ifdef O_NONBLOCK
+	int flags = fcntl(c->socket, F_GETFL);
+
+	if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
+		logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl", strerror(errno));
+	}
+
+#elif defined(WIN32)
+	unsigned long arg = 1;
+
+	if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
+		logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
+	}
+
 #endif
 
-	cp();
+#if defined(SOL_TCP) && defined(TCP_NODELAY)
+	int nodelay = 1;
+	setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&nodelay, sizeof(nodelay));
+#endif
 
-	nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+#if defined(IP_TOS) && defined(IPTOS_LOWDELAY)
+	int lowdelay = IPTOS_LOWDELAY;
+	setsockopt(c->socket, IPPROTO_IP, IP_TOS, (void *)&lowdelay, sizeof(lowdelay));
+#endif
+}
 
-	if(nfd < 0) {
-		logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
-		return -1;
+static bool bind_to_address(meshlink_handle_t *mesh, connection_t *c) {
+	int s = -1;
+
+	for(int i = 0; i < mesh->listen_sockets && mesh->listen_socket[i].bindto; i++) {
+		if(mesh->listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family) {
+			continue;
+		}
+
+		if(s >= 0) {
+			return false;
+		}
+
+		s = i;
 	}
 
-#ifdef O_NONBLOCK
-	flags = fcntl(nfd, F_GETFL);
+	if(s < 0) {
+		return false;
+	}
 
-	if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
-		closesocket(nfd);
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
-			   strerror(errno));
+	sockaddr_t sa = mesh->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(mesh, MESHLINK_WARNING, "Can't bind outgoing socket: %s", strerror(errno));
+		return false;
+	}
+
+	return true;
+}
+
+int setup_listen_socket(const sockaddr_t *sa) {
+	int nfd;
+	char *addrstr;
+	int option;
+
+	nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+
+	if(nfd < 0) {
+		logger(NULL, MESHLINK_ERROR, "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_TCP) && defined(TCP_NODELAY)
-	setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-#endif
-
-#if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
-	option = IPTOS_LOWDELAY;
-	setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
-#endif
+#if defined(IPV6_V6ONLY)
 
-	if(get_config_string
-	   (lookup_config(config_tree, "BindToInterface"), &iface)) {
-#if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
-		memset(&ifr, 0, sizeof(ifr));
-		strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
+	if(sa->sa.sa_family == AF_INET6) {
+		setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
+	}
 
-		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;
-		}
 #else
-		logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
+#warning IPV6_V6ONLY not defined
 #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(NULL, MESHLINK_ERROR, "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(NULL, MESHLINK_ERROR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 		return -1;
 	}
 
 	return nfd;
 }
 
-int setup_vpn_in_socket(const sockaddr_t *sa)
-{
-	int nfd, flags;
+int setup_vpn_in_socket(meshlink_handle_t *mesh, const sockaddr_t *sa) {
+	int nfd;
 	char *addrstr;
 	int option;
-#if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
-	char *iface;
-	struct ifreq ifr;
-#endif
-
-	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(mesh, MESHLINK_ERROR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 		return -1;
 	}
 
-#ifdef O_NONBLOCK
-	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",
-			   strerror(errno));
-		return -1;
-	}
+#ifdef FD_CLOEXEC
+	fcntl(nfd, F_SETFD, FD_CLOEXEC);
 #endif
 
-	option = 1;
-	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
+#ifdef O_NONBLOCK
+	{
+		int flags = fcntl(nfd, F_GETFL);
 
-#if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
-	if(get_config_string
-	   (lookup_config(config_tree, "BindToInterface"), &iface)) {
-		memset(&ifr, 0, sizeof(ifr));
-		strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
+		if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
+			closesocket(nfd);
+			logger(mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl",
+			       strerror(errno));
+			return -1;
+		}
+	}
+#elif defined(WIN32)
+	{
+		unsigned long arg = 1;
 
-		if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
+		if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 			closesocket(nfd);
-			logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
-				   strerror(errno));
+			logger(mesh, MESHLINK_ERROR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 			return -1;
 		}
 	}
 #endif
 
+	option = 1;
+	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
+	setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
+
+#if defined(IPV6_V6ONLY)
+
+	if(sa->sa.sa_family == AF_INET6) {
+		setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
+	}
+
+#endif
+
+#if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
+#define IP_DONTFRAGMENT IP_DONTFRAG
+#endif
+
+#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
+
+	if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
+		option = IP_PMTUDISC_DO;
+		setsockopt(nfd, IPPROTO_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
+	}
+
+#elif defined(IP_DONTFRAGMENT)
+
+	if(mesh->self->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(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
+
+	if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
+		option = IPV6_PMTUDISC_DO;
+		setsockopt(nfd, IPPROTO_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
+	}
+
+#elif defined(IPV6_DONTFRAG)
+
+	if(mesh->self->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(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(mesh, MESHLINK_ERROR, "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(event_loop_t *loop, void *data) {
+	meshlink_handle_t *mesh = loop->data;
+	outgoing_t *outgoing = data;
+	setup_outgoing_connection(mesh, outgoing);
 }
 
-void retry_outgoing(outgoing_t *outgoing)
-{
-	event_t *event;
+void retry_outgoing(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	outgoing->timeout += 5;
+
+	if(outgoing->timeout > mesh->maxtimeout) {
+		outgoing->timeout = mesh->maxtimeout;
+	}
 
-	cp();
+	timeout_add(&mesh->loop, &outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval) {
+		outgoing->timeout, rand() % 100000
+	});
 
-	outgoing->timeout += 5;
+	logger(mesh, MESHLINK_INFO, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
+}
 
-	if(outgoing->timeout > maxtimeout)
-		outgoing->timeout = maxtimeout;
+void finish_connecting(meshlink_handle_t *mesh, connection_t *c) {
+	logger(mesh, MESHLINK_INFO, "Connected to %s", c->name);
 
-	event = new_event();
-	event->handler = (event_handler_t) setup_outgoing_connection;
-	event->time = now + outgoing->timeout;
-	event->data = outgoing;
-	event_add(event);
+	c->last_ping_time = mesh->loop.now.tv_sec;
+	c->status.connecting = false;
 
-	ifdebug(CONNECTIONS) logger(LOG_NOTICE,
-			   _("Trying to re-establish outgoing connection in %d seconds"),
-			   outgoing->timeout);
+	send_id(mesh, c);
 }
 
-void finish_connecting(connection_t *c)
-{
-	cp();
+static void handle_meta_write(meshlink_handle_t *mesh, connection_t *c) {
+	if(c->outbuf.len <= c->outbuf.offset) {
+		return;
+	}
 
-	ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
+	ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, MSG_NOSIGNAL);
+
+	if(outlen <= 0) {
+		if(!errno || errno == EPIPE) {
+			logger(mesh, MESHLINK_INFO, "Connection closed by %s", c->name);
+		} else if(sockwouldblock(sockerrno)) {
+			logger(mesh, MESHLINK_DEBUG, "Sending %lu bytes to %s would block", (unsigned long)(c->outbuf.len - c->outbuf.offset), c->name);
+			return;
+		} else {
+			logger(mesh, MESHLINK_ERROR, "Could not send %lu bytes of data to %s: %s", (unsigned long)(c->outbuf.len - c->outbuf.offset), c->name, strerror(errno));
+		}
+
+		terminate_connection(mesh, c, c->status.active);
+		return;
+	}
 
-	c->last_ping_time = now;
+	buffer_read(&c->outbuf, outlen);
 
-	send_id(c);
+	if(!c->outbuf.len) {
+		io_set(&mesh->loop, &c->io, IO_READ);
+	}
 }
 
-void do_outgoing_connection(connection_t *c)
-{
-	char *address, *port;
-	int option, result, flags;
+static void handle_meta_io(event_loop_t *loop, void *data, int flags) {
+	meshlink_handle_t *mesh = loop->data;
+	connection_t *c = data;
 
-	cp();
+	if(c->status.connecting) {
+		c->status.connecting = false;
 
-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);
-			c->status.remove = true;
-			retry_outgoing(c->outgoing);
+		int result;
+		socklen_t len = sizeof(result);
+		getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
+
+		if(!result) {
+			finish_connecting(mesh, c);
+		} else {
+			logger(mesh, MESHLINK_DEBUG, "Error while connecting to %s: %s", c->name, sockstrerror(result));
+			terminate_connection(mesh, c, false);
 			return;
 		}
+	}
 
-		get_config_string(c->outgoing->cfg, &address);
+	if(flags & IO_WRITE) {
+		handle_meta_write(mesh, c);
+	} else {
+		handle_meta_connection_data(mesh, c);
+	}
+}
 
-		if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
-			asprintf(&port, "655");
+// 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;
 
-		c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
-		free(address);
-		free(port);
+	for splay_each(edge_t, e, n->edge_tree) {
+		if(!e->reverse) {
+			continue;
+		}
 
-		c->outgoing->aip = c->outgoing->ai;
-		c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
-	}
+		bool found = false;
 
-	if(!c->outgoing->aip) {
-		freeaddrinfo(c->outgoing->ai);
-		c->outgoing->ai = NULL;
-		goto begin;
+		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;
+		}
+
+		// Create a new struct addrinfo, and put it at the head of the list.
+		struct addrinfo *nai = xzalloc(sizeof(*nai) + SALEN(e->reverse->address.sa));
+		nai->ai_next = ai;
+		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 = (struct sockaddr *)(nai + 1);
+		memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
 	}
 
-	memcpy(&c->address, c->outgoing->aip->ai_addr,
-		   c->outgoing->aip->ai_addrlen);
-	c->outgoing->aip = c->outgoing->aip->ai_next;
+	return ai;
+}
 
-	if(c->hostname)
-		free(c->hostname);
+// Free struct addrinfo list from get_known_addresses().
+static void free_known_addresses(struct addrinfo *ai) {
+	for(struct addrinfo *aip = ai, *next; aip; aip = next) {
+		next = aip->ai_next;
+		free(aip);
+	}
+}
 
-	c->hostname = sockaddr2hostname(&c->address);
+static bool get_recent(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	node_t *n = lookup_node(mesh, outgoing->name);
 
-	ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
-			   c->hostname);
+	if(!n) {
+		return false;
+	}
 
-	c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+	outgoing->ai = get_known_addresses(n);
+	outgoing->aip = outgoing->ai;
+	return outgoing->aip;
+}
 
-	if(c->socket == -1) {
-		ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
-				   strerror(errno));
+static bool get_next_ai(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	if(!outgoing->ai) {
+		char *address = NULL;
+
+		if(get_config_string(outgoing->cfg, &address)) {
+			char *port;
+			char *space = strchr(address, ' ');
+
+			if(space) {
+				port = xstrdup(space + 1);
+				*space = 0;
+			} else {
+				if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port)) {
+					logger(mesh, MESHLINK_ERROR, "No Port known for %s", outgoing->name);
+					return false;
+				}
+			}
+
+			outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
+			free(port);
+			free(address);
+		}
 
-		goto begin;
+		outgoing->aip = outgoing->ai;
+	} else {
+		outgoing->aip = outgoing->aip->ai_next;
 	}
 
-	/* Optimize TCP settings */
+	return outgoing->aip;
+}
 
-#if defined(SOL_TCP) && defined(TCP_NODELAY)
-	option = 1;
-	setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-#endif
+static bool get_next_cfg(meshlink_handle_t *mesh, outgoing_t *outgoing, char *variable) {
+	(void)mesh;
 
-#if defined(SOL_IP) && defined(IP_TOS)
-	option = IPTOS_LOWDELAY;
-	setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
-#endif
+	if(!outgoing->cfg) {
+		outgoing->cfg = lookup_config(outgoing->config_tree, variable);
+	} else {
+		outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
+	}
 
-	/* Non-blocking */
+	return outgoing->cfg;
+}
 
-#ifdef O_NONBLOCK
-	flags = fcntl(c->socket, F_GETFL);
+static bool get_next_outgoing_address(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	bool start = false;
 
-	if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
-		logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
+	if(outgoing->state == OUTGOING_START) {
+		start = true;
+		outgoing->state = OUTGOING_CANONICAL;
 	}
-#endif
 
-	/* Connect */
+	if(outgoing->state == OUTGOING_CANONICAL) {
+		if(outgoing->aip || get_next_cfg(mesh, outgoing, "CanonicalAddress")) {
+			if(get_next_ai(mesh, outgoing)) {
+				return true;
+			} else {
+				freeaddrinfo(outgoing->ai);
+				outgoing->ai = NULL;
+				outgoing->aip = NULL;
+			}
+		}
 
-	result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
+		outgoing->state = OUTGOING_RECENT;
+	}
 
-	if(result == -1) {
-		if(errno == EINPROGRESS) {
-			c->status.connecting = true;
-			return;
+	if(outgoing->state == OUTGOING_RECENT) {
+		if(outgoing->aip || get_next_cfg(mesh, outgoing, "Address")) {
+			if(get_next_ai(mesh, outgoing)) {
+				return true;
+			} else {
+				freeaddrinfo(outgoing->ai);
+				outgoing->ai = NULL;
+				outgoing->aip = NULL;
+			}
 		}
 
-		closesocket(c->socket);
+		outgoing->state = OUTGOING_KNOWN;
+	}
 
-		ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
+	if(outgoing->state == OUTGOING_KNOWN) {
+		if(outgoing->aip || get_recent(mesh, outgoing)) {
+			if(get_next_ai(mesh, outgoing)) {
+				return true;
+			} else {
+				free_known_addresses(outgoing->ai);
+				outgoing->ai = NULL;
+				outgoing->aip = NULL;
+			}
+		}
 
-		goto begin;
+		outgoing->state = OUTGOING_END;
 	}
 
-	finish_connecting(c);
+	if(start) {
+		outgoing->state = OUTGOING_NO_KNOWN_ADDRESSES;
+	}
 
-	return;
+	return false;
 }
 
-void setup_outgoing_connection(outgoing_t *outgoing)
-{
-	connection_t *c;
-	node_t *n;
+bool do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	struct addrinfo *proxyai = NULL;
+	int result;
 
-	cp();
+begin:
 
-	n = lookup_node(outgoing->name);
+	if(!get_next_outgoing_address(mesh, outgoing)) {
+		if(outgoing->state == OUTGOING_NO_KNOWN_ADDRESSES) {
+			logger(mesh, MESHLINK_ERROR, "No known addresses for %s", outgoing->name);
+		} else {
+			logger(mesh, MESHLINK_ERROR, "Could not set up a meta connection to %s", outgoing->name);
+			retry_outgoing(mesh, outgoing);
+		}
 
-	if(n)
-		if(n->connection) {
-			ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
+		return false;
+	}
 
-			n->connection->outgoing = outgoing;
-			return;
+	connection_t *c = new_connection();
+	c->outgoing = outgoing;
+
+	memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
+
+	char *hostname = sockaddr2hostname(&c->address);
+
+	logger(mesh, MESHLINK_INFO, "Trying to connect to %s at %s", outgoing->name, hostname);
+
+	if(!mesh->proxytype) {
+		c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+		configure_tcp(c);
+	} else {
+		proxyai = str2addrinfo(mesh->proxyhost, mesh->proxyport, SOCK_STREAM);
+
+		if(!proxyai) {
+			free_connection(c);
+			free(hostname);
+			goto begin;
 		}
 
-	c = new_connection();
-	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;
+		logger(mesh, MESHLINK_INFO, "Using proxy at %s port %s", mesh->proxyhost, mesh->proxyport);
+		c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
+		configure_tcp(c);
+	}
 
-	init_configuration(&c->config_tree);
-	read_connection_config(c);
+	if(c->socket == -1) {
+		logger(mesh, MESHLINK_ERROR, "Creating socket for %s at %s failed: %s", c->name, hostname, sockstrerror(sockerrno));
+		free_connection(c);
+		free(hostname);
+		goto begin;
+	}
 
-	outgoing->cfg = lookup_config(c->config_tree, "Address");
+	free(hostname);
 
-	if(!outgoing->cfg) {
-		logger(LOG_ERR, _("No address specified for %s"), c->name);
+#ifdef FD_CLOEXEC
+	fcntl(c->socket, F_SETFD, FD_CLOEXEC);
+#endif
+
+#if defined(IPV6_V6ONLY)
+
+	if(c->address.sa.sa_family == AF_INET6) {
+		static const int option = 1;
+		setsockopt(c->socket, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
+	}
+
+#endif
+
+	bind_to_address(mesh, c);
+
+	/* Connect */
+
+	if(!mesh->proxytype) {
+		result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
+	} else {
+		result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
+		freeaddrinfo(proxyai);
+	}
+
+	if(result == -1 && !sockinprogress(sockerrno)) {
+		logger(mesh, MESHLINK_ERROR, "Could not connect to %s: %s", outgoing->name, sockstrerror(sockerrno));
 		free_connection(c);
-		free(outgoing->name);
-		free(outgoing);
+
+		goto begin;
+	}
+
+	/* Now that there is a working socket, fill in the rest and register this connection. */
+
+	c->status.connecting = true;
+	c->name = xstrdup(outgoing->name);
+	c->outcompression = mesh->self->connection->outcompression;
+	c->last_ping_time = mesh->loop.now.tv_sec;
+
+	connection_add(mesh, c);
+
+	io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ | IO_WRITE);
+
+	return true;
+}
+
+void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	bool blacklisted = false;
+	timeout_del(&mesh->loop, &outgoing->ev);
+
+	node_t *n = lookup_node(mesh, outgoing->name);
+
+	if(n && n->connection) {
+		logger(mesh, MESHLINK_INFO, "Already connected to %s", outgoing->name);
+
+		n->connection->outgoing = outgoing;
 		return;
 	}
 
-	c->outgoing = outgoing;
-	c->last_ping_time = now;
 
-	connection_add(c);
+	if(outgoing->ai) {
+		if(outgoing->state == OUTGOING_KNOWN) {
+			free_known_addresses(outgoing->ai);
+		} else {
+			freeaddrinfo(outgoing->ai);
+		}
+	}
+
+	outgoing->cfg = NULL;
 
-	do_outgoing_connection(c);
+	exit_configuration(&outgoing->config_tree); // discard old configuration if present
+	init_configuration(&outgoing->config_tree);
+	read_host_config(mesh, outgoing->config_tree, outgoing->name);
+	get_config_bool(lookup_config(outgoing->config_tree, "blacklisted"), &blacklisted);
+
+	outgoing->state = OUTGOING_START;
+
+	if(blacklisted) {
+		return;
+	}
+
+	do_outgoing_connection(mesh, outgoing);
 }
 
 /*
   accept a new tcp connect and create a
   new connection
 */
-bool handle_new_meta_connection(int sock)
-{
+void handle_new_meta_connection(event_loop_t *loop, void *data, int flags) {
+	(void)flags;
+	meshlink_handle_t *mesh = loop->data;
+	listen_socket_t *l = data;
 	connection_t *c;
-	sockaddr_t sa;
-	int fd, len = sizeof(sa);
-
-	cp();
+	sockaddr_t sa = {0};
+	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(LOG_ERR, _("Accepting a new connection failed: %s"),
-			   strerror(errno));
-		return false;
+		if(errno == EINVAL) { // TODO: check if Windows agrees
+			event_loop_stop(loop);
+			return;
+		}
+
+		logger(mesh, MESHLINK_ERROR, "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 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(mesh->loop.now.tv_sec - samehost_burst_time > samehost_burst) {
+			samehost_burst = 0;
+		} else {
+			samehost_burst -= mesh->loop.now.tv_sec - samehost_burst_time;
+		}
+
+		samehost_burst_time = mesh->loop.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(mesh->loop.now.tv_sec - connection_burst_time > connection_burst) {
+		connection_burst = 0;
+	} else {
+		connection_burst -= mesh->loop.now.tv_sec - connection_burst_time;
+	}
+
+	connection_burst_time = mesh->loop.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->outcipher = myself->connection->outcipher;
-	c->outdigest = myself->connection->outdigest;
-	c->outmaclength = myself->connection->outmaclength;
-	c->outcompression = myself->connection->outcompression;
+	c->name = xstrdup("<unknown>");
+	c->outcompression = mesh->self->connection->outcompression;
 
 	c->address = sa;
-	c->hostname = sockaddr2hostname(&sa);
 	c->socket = fd;
-	c->last_ping_time = now;
+	c->last_ping_time = mesh->loop.now.tv_sec;
 
-	ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
+	char *hostname = sockaddr2hostname(&sa);
+	logger(mesh, MESHLINK_INFO, "Connection from %s", hostname);
+	free(hostname);
 
-	connection_add(c);
+	io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ);
+
+	configure_tcp(c);
+
+	connection_add(mesh, c);
 
 	c->allow_request = ID;
-	send_id(c);
+	send_id(mesh, c);
+}
 
-	return true;
+static void free_outgoing(outgoing_t *outgoing) {
+	meshlink_handle_t *mesh = outgoing->mesh;
+
+	timeout_del(&mesh->loop, &outgoing->ev);
+
+	if(outgoing->ai) {
+		if(outgoing->state == OUTGOING_KNOWN) {
+			free_known_addresses(outgoing->ai);
+		} else {
+			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;
+void try_outgoing_connections(meshlink_handle_t *mesh) {
+	/* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
+
+	if(!mesh->outgoings) {
+		mesh->outgoings = list_alloc((list_action_t)free_outgoing);
+	} else {
+		for list_each(outgoing_t, outgoing, mesh->outgoings) {
+			outgoing->timeout = -1;
+		}
+	}
 
-	cp();
+	/* 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)) {
+	// TODO: Drop support for ConnectTo since AutoConnect is now always on?
+	for(config_t *cfg = lookup_config(mesh->config, "ConnectTo"); cfg; cfg = lookup_config_next(mesh->config, cfg)) {
+		char *name;
 		get_config_string(cfg, &name);
 
 		if(!check_id(name)) {
-			logger(LOG_ERR,
-				   _("Invalid name for outgoing connection in %s line %d"),
-				   cfg->file, cfg->line);
+			logger(mesh, MESHLINK_ERROR,
+			       "Invalid name for outgoing connection in line %d",
+			       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, mesh->outgoings) {
+			if(!strcmp(outgoing->name, name)) {
+				found = true;
+				outgoing->timeout = 0;
+				break;
+			}
+		}
+
+		if(!found) {
+			outgoing_t *outgoing = xzalloc(sizeof(*outgoing));
+			outgoing->mesh = mesh;
+			outgoing->name = name;
+			list_insert_tail(mesh->outgoings, outgoing);
+			setup_outgoing_connection(mesh, outgoing);
+		}
+	}
+
+	/* Terminate any connections whose outgoing_t is to be deleted. */
+
+	for list_each(connection_t, c, mesh->connections) {
+		if(c->outgoing && c->outgoing->timeout == -1) {
+			c->outgoing = NULL;
+			logger(mesh, MESHLINK_INFO, "No more outgoing connection to %s", c->name);
+			terminate_connection(mesh, c, c->status.active);
+		}
 	}
+
+	/* Delete outgoing_ts for which there is no ConnectTo. */
+
+	for list_each(outgoing_t, outgoing, mesh->outgoings)
+		if(outgoing->timeout == -1) {
+			list_delete_node(mesh->outgoings, node);
+		}
 }