X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fnet_socket.c;h=3047ccbd8bfedeae2debdeb717bdf441c7bb040f;hb=2fd608c4111ef4d48a649401d918f5981856cc44;hp=544cd6e204f0bbeb0165ced1427448e5b8bf2b1b;hpb=b58d95eb29662bce4388f95dbc5762b9e2999806;p=meshlink

diff --git a/src/net_socket.c b/src/net_socket.c
index 544cd6e2..3047ccbd 100644
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -1,9 +1,6 @@
 /*
     net_socket.c -- Handle various kinds of sockets.
-    Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2012 Guus Sliepen <guus@tinc-vpn.org>
-                  2006      Scott Lamb <slamb@slamb.org>
-                  2009      Florian Forster <octo@verplant.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
@@ -22,11 +19,11 @@
 
 #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"
@@ -39,71 +36,75 @@
 #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;
-int udp_rcvbuf = 0;
-int udp_sndbuf = 0;
-
-listen_socket_t listen_socket[MAXSOCKETS];
-int listen_sockets;
-list_t *outgoing_list = NULL;
+int max_connection_burst = 100;
 
 /* Setup sockets */
 
 static void configure_tcp(connection_t *c) {
-	int option;
-
 #ifdef O_NONBLOCK
 	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(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(LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
+		logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 	}
+
 #endif
 
 #if defined(SOL_TCP) && defined(TCP_NODELAY)
-	option = 1;
-	setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof(option));
+	int nodelay = 1;
+	setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&nodelay, sizeof(nodelay));
 #endif
 
-#if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
-	option = IPTOS_LOWDELAY;
-	setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof(option));
+#if defined(IP_TOS) && defined(IPTOS_LOWDELAY)
+	int lowdelay = IPTOS_LOWDELAY;
+	setsockopt(c->socket, IPPROTO_IP, IP_TOS, (void *)&lowdelay, sizeof(lowdelay));
 #endif
 }
 
-static bool bind_to_interface(int sd) {
-	char *iface;
+static bool bind_to_address(meshlink_handle_t *mesh, connection_t *c) {
+	int s = -1;
 
-#if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
-	struct ifreq ifr;
-	int status;
-#endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
+	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(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
-		return true;
+		if(s >= 0) {
+			return false;
+		}
 
-#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;
+		s = i;
+	}
 
-	status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
-	if(status) {
-		logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
-				strerror(errno));
+	if(s < 0) {
+		return false;
+	}
+
+	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;
 	}
-#else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
-	logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
-#endif
 
 	return true;
 }
@@ -112,12 +113,11 @@ int setup_listen_socket(const sockaddr_t *sa) {
 	int nfd;
 	char *addrstr;
 	int option;
-	char *iface;
 
 	nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 
 	if(nfd < 0) {
-		ifdebug(STATUS) logger(LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
+		logger(NULL, MESHLINK_ERROR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 		return -1;
 	}
 
@@ -130,48 +130,34 @@ int setup_listen_socket(const sockaddr_t *sa) {
 	option = 1;
 	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;
+#if defined(IPV6_V6ONLY)
 
-		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, (void *)&ifr, sizeof(ifr))) {
-			closesocket(nfd);
-			logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
-				   strerror(sockerrno));
-			return -1;
-		}
 #else
-		logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
+#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, sockstrerror(sockerrno));
+		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", sockstrerror(sockerrno));
+		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 setup_vpn_in_socket(meshlink_handle_t *mesh, const sockaddr_t *sa) {
 	int nfd;
 	char *addrstr;
 	int option;
@@ -179,7 +165,7 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 	nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 
 	if(nfd < 0) {
-		logger(LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
+		logger(mesh, MESHLINK_ERROR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 		return -1;
 	}
 
@@ -193,17 +179,18 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 
 		if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 			closesocket(nfd);
-			logger(LOG_ERR, "System call `%s' failed: %s", "fcntl",
-				   strerror(errno));
+			logger(mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl",
+			       strerror(errno));
 			return -1;
 		}
 	}
 #elif defined(WIN32)
 	{
 		unsigned long arg = 1;
+
 		if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 			closesocket(nfd);
-			logger(LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
+			logger(mesh, MESHLINK_ERROR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 			return -1;
 		}
 	}
@@ -213,58 +200,58 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 	setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 	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(LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
+#if defined(IPV6_V6ONLY)
 
-	if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
-		logger(LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
+	if(sa->sa.sa_family == AF_INET6) {
+		setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
+	}
 
-#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(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 #define IP_DONTFRAGMENT IP_DONTFRAG
 #endif
 
-#if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
-	if(myself->options & OPTION_PMTU_DISCOVERY) {
+#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
+
+	if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 		option = IP_PMTUDISC_DO;
-		setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
+		setsockopt(nfd, IPPROTO_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 	}
-#elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
-	if(myself->options & OPTION_PMTU_DISCOVERY) {
+
+#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(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
-	if(myself->options & OPTION_PMTU_DISCOVERY) {
+#if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
+
+	if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 		option = IPV6_PMTUDISC_DO;
-		setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
+		setsockopt(nfd, IPPROTO_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 	}
-#elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
-	if(myself->options & OPTION_PMTU_DISCOVERY) {
+
+#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_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, sockstrerror(sockerrno));
+		logger(mesh, MESHLINK_ERROR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 		free(addrstr);
 		return -1;
 	}
@@ -272,267 +259,559 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 	return nfd;
 } /* int setup_vpn_in_socket */
 
-void retry_outgoing(outgoing_t *outgoing) {
+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(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 	outgoing->timeout += 5;
 
-	if(outgoing->timeout > maxtimeout)
-		outgoing->timeout = maxtimeout;
+	if(outgoing->timeout > mesh->maxtimeout) {
+		outgoing->timeout = mesh->maxtimeout;
+	}
 
-	if(outgoing->event)
-		event_del(outgoing->event);
-	outgoing->event = new_event();
-	outgoing->event->handler = (event_handler_t) setup_outgoing_connection;
-	outgoing->event->time = now + outgoing->timeout;
-	outgoing->event->data = outgoing;
-	event_add(outgoing->event);
+	timeout_add(&mesh->loop, &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(mesh, MESHLINK_INFO, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 }
 
-void finish_connecting(connection_t *c) {
-	ifdebug(CONNECTIONS) logger(LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
-
-	configure_tcp(c);
+void finish_connecting(meshlink_handle_t *mesh, connection_t *c) {
+	logger(mesh, MESHLINK_INFO, "Connected to %s", c->name);
 
-	c->last_ping_time = now;
+	c->last_ping_time = mesh->loop.now.tv_sec;
+	c->status.connecting = false;
 
-	send_id(c);
+	send_id(mesh, c);
 }
 
-void do_outgoing_connection(connection_t *c) {
-	char *address, *port, *space;
-	struct addrinfo *proxyai;
-	int result;
+static void handle_meta_write(meshlink_handle_t *mesh, connection_t *c) {
+	if(c->outbuf.len <= c->outbuf.offset) {
+		return;
+	}
 
-	if(!c->outgoing) {
-		logger(LOG_ERR, "do_outgoing_connection() for %s called without c->outgoing", c->name);
-		abort();
+	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;
 	}
 
-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);
-			c->outgoing = NULL;
+	buffer_read(&c->outbuf, outlen);
+
+	if(!c->outbuf.len) {
+		io_set(&mesh->loop, &c->io, IO_READ);
+	}
+}
+
+static void handle_meta_io(event_loop_t *loop, void *data, int flags) {
+	meshlink_handle_t *mesh = loop->data;
+	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(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);
+	}
+}
 
-		space = strchr(address, ' ');
-		if(space) {
-			port = xstrdup(space + 1);
-			*space = 0;
+// 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;
+		}
+
+		// 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);
+	}
+
+	return ai;
+}
+
+// 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);
+	}
+}
+
+static bool get_recent(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	node_t *n = lookup_node(mesh, outgoing->name);
+
+	if(!n) {
+		return false;
+	}
+
+	outgoing->ai = get_known_addresses(n);
+	outgoing->aip = outgoing->ai;
+	return outgoing->aip;
+}
+
+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);
+		}
+
+		outgoing->aip = outgoing->ai;
+	} else {
+		outgoing->aip = outgoing->aip->ai_next;
+	}
+
+	return outgoing->aip;
+}
+
+static bool get_next_cfg(meshlink_handle_t *mesh, outgoing_t *outgoing, char *variable) {
+	(void)mesh;
+
+	if(!outgoing->cfg) {
+		outgoing->cfg = lookup_config(outgoing->config_tree, variable);
+	} else {
+		outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
+	}
+
+	return outgoing->cfg;
+}
+
+static bool get_next_outgoing_address(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	bool start = false;
+
+	if(outgoing->state == OUTGOING_START) {
+		start = true;
+		outgoing->state = OUTGOING_CANONICAL;
+	}
+
+	if(outgoing->state == OUTGOING_CANONICAL) {
+		while(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;
+			}
+		}
+
+		outgoing->state = OUTGOING_RECENT;
+	}
+
+	if(outgoing->state == OUTGOING_RECENT) {
+		while(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;
+			}
+		}
+
+		outgoing->state = OUTGOING_KNOWN;
+	}
+
+	if(outgoing->state == OUTGOING_KNOWN) {
+		if(!outgoing->aip) {
+			get_recent(mesh, outgoing);
 		} else {
-			if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
-				port = xstrdup("655");
+			outgoing->aip = outgoing->aip->ai_next;
 		}
 
-		c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
-		free(address);
-		free(port);
+		if(outgoing->aip) {
+			return true;
+		} else {
+			free_known_addresses(outgoing->ai);
+			outgoing->ai = NULL;
+			outgoing->aip = NULL;
+		}
 
-		c->outgoing->aip = c->outgoing->ai;
-		c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
+		outgoing->state = OUTGOING_END;
 	}
 
-	if(!c->outgoing->aip) {
-		if(c->outgoing->ai)
-			freeaddrinfo(c->outgoing->ai);
-		c->outgoing->ai = NULL;
-		goto begin;
+	if(start) {
+		outgoing->state = OUTGOING_NO_KNOWN_ADDRESSES;
 	}
 
-	memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
-	c->outgoing->aip = c->outgoing->aip->ai_next;
+	return false;
+}
 
-	if(c->hostname)
-		free(c->hostname);
+bool do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	struct addrinfo *proxyai = NULL;
+	int result;
 
-	c->hostname = sockaddr2hostname(&c->address);
+begin:
 
-	ifdebug(CONNECTIONS) logger(LOG_INFO, "Trying to connect to %s (%s)", c->name,
-			   c->hostname);
+	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(!proxytype) {
+		return false;
+	}
+
+	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(proxyhost, proxyport, SOCK_STREAM);
-		if(!proxyai)
+		proxyai = str2addrinfo(mesh->proxyhost, mesh->proxyport, SOCK_STREAM);
+
+		if(!proxyai) {
+			free_connection(c);
+			free(hostname);
 			goto begin;
-		ifdebug(CONNECTIONS) logger(LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
+		}
+
+		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);
 	}
 
 	if(c->socket == -1) {
-		ifdebug(CONNECTIONS) logger(LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
+		logger(mesh, MESHLINK_ERROR, "Creating socket for %s at %s failed: %s", c->name, hostname, sockstrerror(sockerrno));
+		free_connection(c);
+		free(hostname);
 		goto begin;
 	}
 
+	free(hostname);
+
 #ifdef FD_CLOEXEC
 	fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 #endif
 
-#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
+#if defined(IPV6_V6ONLY)
 
-	bind_to_interface(c->socket);
+	if(c->address.sa.sa_family == AF_INET6) {
+		static const int option = 1;
+		setsockopt(c->socket, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
+	}
 
-	/* Optimize TCP settings */
+#endif
 
-//	configure_tcp(c);
+	bind_to_address(mesh, c);
 
 	/* Connect */
 
-	if(!proxytype) {
+	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) {
-		if(sockinprogress(sockerrno)) {
-			c->status.connecting = true;
-			return;
-		}
-
-		closesocket(c->socket);
-
-		ifdebug(CONNECTIONS) logger(LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno));
+	if(result == -1 && !sockinprogress(sockerrno)) {
+		logger(mesh, MESHLINK_ERROR, "Could not connect to %s: %s", outgoing->name, 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. */
+
+	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);
 
-	return;
+	io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ | IO_WRITE);
+
+	return true;
 }
 
-void setup_outgoing_connection(outgoing_t *outgoing) {
-	connection_t *c;
-	node_t *n;
+void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
+	bool blacklisted = false;
+	timeout_del(&mesh->loop, &outgoing->ev);
 
-	outgoing->event = NULL;
+	node_t *n = lookup_node(mesh, outgoing->name);
 
-	n = lookup_node(outgoing->name);
+	if(n && n->connection) {
+		logger(mesh, MESHLINK_INFO, "Already connected to %s", outgoing->name);
 
-	if(n)
-		if(n->connection) {
-			ifdebug(CONNECTIONS) logger(LOG_INFO, "Already connected to %s", outgoing->name);
+		n->connection->outgoing = outgoing;
+		return;
+	}
 
-			n->connection->outgoing = outgoing;
-			return;
+
+	if(outgoing->ai) {
+		if(outgoing->state == OUTGOING_KNOWN) {
+			free_known_addresses(outgoing->ai);
+		} else {
+			freeaddrinfo(outgoing->ai);
 		}
+	}
 
-	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;
+	outgoing->cfg = NULL;
 
-	init_configuration(&c->config_tree);
-	read_connection_config(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->cfg = lookup_config(c->config_tree, "Address");
+	outgoing->state = OUTGOING_START;
 
-	if(!outgoing->cfg) {
-		logger(LOG_ERR, "No address specified for %s", c->name);
-		free_connection(c);
+	if(blacklisted) {
 		return;
 	}
 
-	c->outgoing = outgoing;
-	c->last_ping_time = now;
+	if(mesh->connection_try_cb) {
+		node_t *n = lookup_node(mesh, outgoing->name);
+		mesh->connection_try_cb(mesh, (struct meshlink_node *)n);
+	}
+
+	do_outgoing_connection(mesh, outgoing);
+}
+
+/// Delayed close of a filedescriptor.
+static void tarpit(int fd) {
+	static int pits[10] = {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1};
+	static int next_pit = 0;
 
-	connection_add(c);
+	if(pits[next_pit] != -1) {
+		closesocket(pits[next_pit]);
+	}
+
+	pits[next_pit++] = fd;
 
-	do_outgoing_connection(c);
+	if(next_pit >= (int)(sizeof pits / sizeof pits[0])) {
+		next_pit = 0;
+	}
 }
 
 /*
   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;
+	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", sockstrerror(sockerrno));
-		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);
 
+	/* Rate limit incoming connections to max_connection_burst/second. */
+
+	static int connection_burst;
+	static int connection_burst_time;
+
+	if(mesh->loop.now.tv_sec != connection_burst_time) {
+		connection_burst_time = mesh->loop.now.tv_sec;
+		connection_burst = 0;
+	}
+
+	if(connection_burst >= max_connection_burst) {
+		tarpit(fd);
+		return;
+	}
+
+	connection_burst++;
+
+	// Accept the new connection
+
 	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->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);
+
+	io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ);
 
 	configure_tcp(c);
 
-	connection_add(c);
+	connection_add(mesh, c);
 
 	c->allow_request = ID;
-	send_id(c);
-
-	return true;
+	send_id(mesh, c);
 }
 
 static void free_outgoing(outgoing_t *outgoing) {
-	if(outgoing->ai)
-		freeaddrinfo(outgoing->ai);
+	meshlink_handle_t *mesh = outgoing->mesh;
 
-	if(outgoing->name)
+	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;
-	
-	outgoing_list = list_alloc((list_action_t)free_outgoing);
-			
-	for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
+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;
+		}
+	}
+
+	/* Make sure there is one outgoing_t in the list for each ConnectTo. */
+
+	// 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;
-		list_insert_tail(outgoing_list, outgoing);
-		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);
+		}
 }