From 664466227602b6aabd4f601cf57183bbfa45bc08 Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@meshlink.io>
Date: Sat, 19 Jun 2021 22:43:17 +0200
Subject: [PATCH] Remove support for multiple connections.

---
 examples/chat.c         |  27 ---
 src/connection.c        |  25 +--
 src/meshlink.c          | 269 ++-----------------------
 src/meshlink_internal.h |   7 +-
 src/meta.c              |   6 +-
 src/net.c               | 430 +---------------------------------------
 src/net_setup.c         |  10 +-
 src/net_socket.c        |  43 ++--
 src/node.c              |  41 ++--
 src/protocol_auth.c     |  36 ----
 src/protocol_key.c      |   8 +-
 11 files changed, 97 insertions(+), 805 deletions(-)

diff --git a/examples/chat.c b/examples/chat.c
index bf31709..5d06538 100644
--- a/examples/chat.c
+++ b/examples/chat.c
@@ -41,9 +41,6 @@ static void node_status(meshlink_handle_t *mesh, meshlink_node_t *node, bool rea
 	}
 }
 
-static meshlink_node_t **nodes;
-static size_t nnodes;
-
 static void parse_command(meshlink_handle_t *mesh, char *buf) {
 	char *arg = strchr(buf, ' ');
 
@@ -69,30 +66,6 @@ static void parse_command(meshlink_handle_t *mesh, char *buf) {
 			fprintf(stderr, "Could not restart MeshLink: %s\n", meshlink_strerror(meshlink_errno));
 			exit(1);
 		}
-	} else if(!strcasecmp(buf, "who")) {
-		if(!arg) {
-			nodes = meshlink_get_all_nodes(mesh, nodes, &nnodes);
-
-			if(!nnodes) {
-				fprintf(stderr, "Could not get list of nodes: %s\n", meshlink_strerror(meshlink_errno));
-			} else {
-				printf("%zu known nodes:", nnodes);
-
-				for(size_t i = 0; i < nnodes; i++) {
-					printf(" %s", nodes[i]->name);
-				}
-
-				printf("\n");
-			}
-		} else {
-			meshlink_node_t *node = meshlink_get_node(mesh, arg);
-
-			if(!node) {
-				fprintf(stderr, "Error looking up '%s': %s\n", arg, meshlink_strerror(meshlink_errno));
-			} else {
-				printf("Node %s found\n", arg);
-			}
-		}
 	} else if(!strcasecmp(buf, "quit")) {
 		printf("Bye!\n");
 		fclose(stdin);
diff --git a/src/connection.c b/src/connection.c
index 9cc6491..97e3918 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -29,25 +29,15 @@
 #include "xalloc.h"
 
 void init_connections(meshlink_handle_t *mesh) {
-	assert(!mesh->connections);
-	assert(!mesh->everyone);
-
-	mesh->connections = list_alloc((list_action_t) free_connection);
-	mesh->everyone = new_connection();
-	mesh->everyone->name = xstrdup("mesh->everyone");
+	assert(!mesh->connection);
 }
 
 void exit_connections(meshlink_handle_t *mesh) {
-	if(mesh->connections) {
-		list_delete_list(mesh->connections);
-	}
-
-	if(mesh->everyone) {
-		free_connection(mesh->everyone);
+	if(mesh->connection) {
+		free_connection(mesh->connection);
 	}
 
-	mesh->connections = NULL;
-	mesh->everyone = NULL;
+	mesh->connection = NULL;
 }
 
 connection_t *new_connection(void) {
@@ -78,14 +68,17 @@ void free_connection(connection_t *c) {
 
 void connection_add(meshlink_handle_t *mesh, connection_t *c) {
 	assert(c);
+	assert(!mesh->connection);
 
 	c->mesh = mesh;
-	list_insert_tail(mesh->connections, c);
+	mesh->connection = c;
 }
 
 void connection_del(meshlink_handle_t *mesh, connection_t *c) {
 	assert(c);
+	assert(mesh->connection == c);
 
 	io_del(&mesh->loop, &c->io);
-	list_delete(mesh->connections, c);
+	free(mesh->connection);
+	mesh->connection = NULL;
 }
diff --git a/src/meshlink.c b/src/meshlink.c
index 8b3b841..19d9fdc 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -488,32 +488,17 @@ static bool ecdsa_keygen(meshlink_handle_t *mesh) {
 	return true;
 }
 
-static bool timespec_lt(const struct timespec *a, const struct timespec *b) {
-	if(a->tv_sec == b->tv_sec) {
-		return a->tv_nsec < b->tv_nsec;
-	} else {
-		return a->tv_sec < b->tv_sec;
-	}
-}
-
 static struct timespec idle(event_loop_t *loop, void *data) {
 	(void)loop;
 	meshlink_handle_t *mesh = data;
-	struct timespec t, tmin = {3600, 0};
-
-	for splay_each(node_t, n, mesh->nodes) {
-		if(!n->utcp) {
-			continue;
-		}
 
-		t = utcp_timeout(n->utcp);
-
-		if(timespec_lt(&t, &tmin)) {
-			tmin = t;
-		}
+	if(mesh->peer && mesh->peer->utcp) {
+		return utcp_timeout(mesh->peer->utcp);
+	} else {
+		return (struct timespec) {
+			3600, 0
+		};
 	}
-
-	return tmin;
 }
 
 static bool meshlink_setup(meshlink_handle_t *mesh) {
@@ -1156,11 +1141,10 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 	}
 
 	// Reset node connection timers
-	for splay_each(node_t, n, mesh->nodes) {
-		n->last_connect_try = 0;
+	if(mesh->peer) {
+		mesh->peer->last_connect_try = 0;
 	}
 
-
 	//Check that a valid name is set
 	if(!mesh->name) {
 		logger(mesh, MESHLINK_ERROR, "No name given!\n");
@@ -1229,25 +1213,17 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 	}
 
 	// Close all metaconnections
-	if(mesh->connections) {
-		for(list_node_t *node = mesh->connections->head, *next; node; node = next) {
-			next = node->next;
-			connection_t *c = node->data;
-			c->outgoing = NULL;
-			terminate_connection(mesh, c, false);
-		}
+	if(mesh->connection) {
+		mesh->connection->outgoing = NULL;
+		terminate_connection(mesh, mesh->connection, false);
 	}
 
 	exit_outgoings(mesh);
 
 	// Try to write out any changed node config files, ignore errors at this point.
-	if(mesh->nodes) {
-		for splay_each(node_t, n, mesh->nodes) {
-			if(n->status.dirty) {
-				if(!node_write_config(mesh, n, false)) {
-					// ignore
-				}
-			}
+	if(mesh->peer && mesh->peer->status.dirty) {
+		if(!node_write_config(mesh, mesh->peer, false)) {
+			// ignore
 		}
 	}
 
@@ -1703,149 +1679,6 @@ meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
 	return (meshlink_node_t *)n;
 }
 
-meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_t **nodes, size_t *nmemb) {
-	if(!mesh || !nmemb || (*nmemb && !nodes)) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return NULL;
-	}
-
-	meshlink_node_t **result;
-
-	//lock mesh->nodes
-	if(pthread_mutex_lock(&mesh->mutex) != 0) {
-		abort();
-	}
-
-	*nmemb = mesh->nodes->count;
-	result = realloc(nodes, *nmemb * sizeof(*nodes));
-
-	if(result) {
-		meshlink_node_t **p = result;
-
-		for splay_each(node_t, n, mesh->nodes) {
-			*p++ = (meshlink_node_t *)n;
-		}
-	} else {
-		*nmemb = 0;
-		free(nodes);
-		meshlink_errno = MESHLINK_ENOMEM;
-	}
-
-	pthread_mutex_unlock(&mesh->mutex);
-
-	return result;
-}
-
-static meshlink_node_t **meshlink_get_all_nodes_by_condition(meshlink_handle_t *mesh, const void *condition, meshlink_node_t **nodes, size_t *nmemb, search_node_by_condition_t search_node) {
-	meshlink_node_t **result;
-
-	if(pthread_mutex_lock(&mesh->mutex) != 0) {
-		abort();
-	}
-
-	*nmemb = 0;
-
-	for splay_each(node_t, n, mesh->nodes) {
-		if(search_node(n, condition)) {
-			++*nmemb;
-		}
-	}
-
-	if(*nmemb == 0) {
-		free(nodes);
-		pthread_mutex_unlock(&mesh->mutex);
-		return NULL;
-	}
-
-	result = realloc(nodes, *nmemb * sizeof(*nodes));
-
-	if(result) {
-		meshlink_node_t **p = result;
-
-		for splay_each(node_t, n, mesh->nodes) {
-			if(search_node(n, condition)) {
-				*p++ = (meshlink_node_t *)n;
-			}
-		}
-	} else {
-		*nmemb = 0;
-		free(nodes);
-		meshlink_errno = MESHLINK_ENOMEM;
-	}
-
-	pthread_mutex_unlock(&mesh->mutex);
-
-	return result;
-}
-
-static bool search_node_by_dev_class(const node_t *node, const void *condition) {
-	dev_class_t *devclass = (dev_class_t *)condition;
-
-	if(*devclass == (dev_class_t)node->devclass) {
-		return true;
-	}
-
-	return false;
-}
-
-
-struct time_range {
-	time_t start;
-	time_t end;
-};
-
-meshlink_node_t **meshlink_get_all_nodes_by_dev_class(meshlink_handle_t *mesh, dev_class_t devclass, meshlink_node_t **nodes, size_t *nmemb) {
-	if(!mesh || devclass < 0 || devclass >= DEV_CLASS_COUNT || !nmemb) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return NULL;
-	}
-
-	return meshlink_get_all_nodes_by_condition(mesh, &devclass, nodes, nmemb, search_node_by_dev_class);
-}
-
-dev_class_t meshlink_get_node_dev_class(meshlink_handle_t *mesh, meshlink_node_t *node) {
-	if(!mesh || !node) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return -1;
-	}
-
-	dev_class_t devclass;
-
-	if(pthread_mutex_lock(&mesh->mutex) != 0) {
-		abort();
-	}
-
-	devclass = ((node_t *)node)->devclass;
-
-	pthread_mutex_unlock(&mesh->mutex);
-
-	return devclass;
-}
-
-bool meshlink_get_node_reachability(struct meshlink_handle *mesh, struct meshlink_node *node, time_t *last_reachable, time_t *last_unreachable) {
-	if(!mesh || !node) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return NULL;
-	}
-
-	node_t *n = (node_t *)node;
-	bool reachable;
-
-	if(pthread_mutex_lock(&mesh->mutex) != 0) {
-		abort();
-	}
-
-	reachable = n->status.reachable && !n->status.blacklisted;
-
-	// TODO: handle reachable times?
-	(void)last_reachable;
-	(void)last_unreachable;
-
-	pthread_mutex_unlock(&mesh->mutex);
-
-	return reachable;
-}
-
 bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *signature, size_t *siglen) {
 	logger(mesh, MESHLINK_DEBUG, "meshlink_sign(%p, %zu, %p, %p)", data, len, signature, (void *)siglen);
 
@@ -2017,7 +1850,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	}
 
 	// Refuse to join a mesh if we are already part of one. We are part of one if we know at least one other node.
-	if(mesh->nodes->count > 1) {
+	if(mesh->peer) {
 		logger(mesh, MESHLINK_ERROR, "Already part of an existing mesh\n");
 		meshlink_errno = MESHLINK_EINVAL;
 		goto exit;
@@ -2429,66 +2262,6 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 	return true;
 }
 
-bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
-	logger(mesh, MESHLINK_DEBUG, "meshlink_forget_node(%s)", node ? node->name : "(null)");
-
-	if(!mesh || !node) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return false;
-	}
-
-	node_t *n = (node_t *)node;
-
-	if(pthread_mutex_lock(&mesh->mutex) != 0) {
-		abort();
-	}
-
-	/* Check that the node is not reachable */
-	if(n->status.reachable || n->connection) {
-		pthread_mutex_unlock(&mesh->mutex);
-		logger(mesh, MESHLINK_WARNING, "Could not forget %s: still reachable", n->name);
-		return false;
-	}
-
-	/* Check that we don't have any active UTCP connections */
-	if(n->utcp && utcp_is_active(n->utcp)) {
-		pthread_mutex_unlock(&mesh->mutex);
-		logger(mesh, MESHLINK_WARNING, "Could not forget %s: active UTCP connections", n->name);
-		return false;
-	}
-
-	/* Check that we have no active connections to this node */
-	for list_each(connection_t, c, mesh->connections) {
-		if(c->node == n) {
-			pthread_mutex_unlock(&mesh->mutex);
-			logger(mesh, MESHLINK_WARNING, "Could not forget %s: active connection", n->name);
-			return false;
-		}
-	}
-
-	/* Remove any pending outgoings to this node */
-	if(mesh->outgoings) {
-		for list_each(outgoing_t, outgoing, mesh->outgoings) {
-			if(outgoing->node == n) {
-				list_delete_node(mesh->outgoings, list_node);
-			}
-		}
-	}
-
-	/* Delete the config file for this node */
-	if(!config_delete(mesh, "current", n->name)) {
-		pthread_mutex_unlock(&mesh->mutex);
-		return false;
-	}
-
-	/* Delete the node struct and any remaining edges referencing this node */
-	node_del(mesh, n);
-
-	pthread_mutex_unlock(&mesh->mutex);
-
-	return config_sync(mesh, "current");
-}
-
 /* Hint that a hostname may be found at an address
  * See header file for detailed comment.
  */
@@ -2863,12 +2636,10 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 	mesh->channel_accept_cb = cb;
 	mesh->receive_cb = channel_receive;
 
-	for splay_each(node_t, n, mesh->nodes) {
-		if(!n->utcp && n != mesh->self) {
-			n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
-			utcp_set_mtu(n->utcp, n->mtu - sizeof(meshlink_packethdr_t));
-			utcp_set_retransmit_cb(n->utcp, channel_retransmit);
-		}
+	if(mesh->peer) {
+		mesh->peer->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, mesh->peer);
+		utcp_set_mtu(mesh->peer->utcp, mesh->peer->mtu - sizeof(meshlink_packethdr_t));
+		utcp_set_retransmit_cb(mesh->peer->utcp, channel_retransmit);
 	}
 
 	pthread_mutex_unlock(&mesh->mutex);
@@ -3514,7 +3285,7 @@ void meshlink_set_storage_policy(struct meshlink_handle *mesh, meshlink_storage_
 void handle_network_change(meshlink_handle_t *mesh, bool online) {
 	(void)online;
 
-	if(!mesh->connections || !mesh->loop.running) {
+	if(!mesh->loop.running) {
 		return;
 	}
 
diff --git a/src/meshlink_internal.h b/src/meshlink_internal.h
index b1caa0a..fc4683e 100644
--- a/src/meshlink_internal.h
+++ b/src/meshlink_internal.h
@@ -93,10 +93,9 @@ struct meshlink_handle {
 	meshlink_queue_t outpacketqueue;
 	signal_t datafromapp;
 
-	struct splay_tree_t *nodes;
-
-	struct list_t *connections;
-	struct list_t *outgoings;
+	struct node_t *peer;
+	struct connection_t *connection;
+	struct outgoing_t *outgoing;
 
 	// Meta-connection-related members
 	struct splay_tree_t *past_request_tree;
diff --git a/src/meta.c b/src/meta.c
index d79dc6e..32e3de2 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -64,9 +64,9 @@ void broadcast_meta(meshlink_handle_t *mesh, connection_t *from, const char *buf
 	assert(buffer);
 	assert(length);
 
-	for list_each(connection_t, c, mesh->connections)
-		if(c != from && c->status.active) {
-			send_meta(mesh, c, buffer, length);
+	if(mesh->connection)
+		if(mesh->connection != from && mesh->connection->status.active) {
+			send_meta(mesh, mesh->connection, buffer, length);
 		}
 }
 
diff --git a/src/net.c b/src/net.c
index 60c16cb..c05baf7 100644
--- a/src/net.c
+++ b/src/net.c
@@ -90,7 +90,7 @@ static void timeout_handler(event_loop_t *loop, void *data) {
 	meshlink_handle_t *mesh = loop->data;
 	logger(mesh, MESHLINK_DEBUG, "timeout_handler()");
 
-	for list_each(connection_t, c, mesh->connections) {
+	for(connection_t *c = mesh->connection; c; c = NULL) {
 		int pingtimeout = c->node ? mesh->dev_class_traits[c->node->devclass].pingtimeout : default_timeout;
 		int pinginterval = c->node ? mesh->dev_class_traits[c->node->devclass].pinginterval : default_interval;
 
@@ -144,186 +144,6 @@ static void timeout_handler(event_loop_t *loop, void *data) {
 	});
 }
 
-// devclass asc, last_successfull_connection desc
-static int node_compare_devclass_asc_lsc_desc(const void *a, const void *b) {
-	const node_t *na = a, *nb = b;
-
-	if(na->devclass < nb->devclass) {
-		return -1;
-	}
-
-	if(na->devclass > nb->devclass) {
-		return 1;
-	}
-
-	if(na->last_successfull_connection == nb->last_successfull_connection) {
-		return 0;
-	}
-
-	if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
-		return -1;
-	}
-
-	if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
-		return 1;
-	}
-
-	if(na < nb) {
-		return -1;
-	}
-
-	if(na > nb) {
-		return 1;
-	}
-
-	return 0;
-}
-
-// last_successfull_connection desc
-static int node_compare_lsc_desc(const void *a, const void *b) {
-	const node_t *na = a, *nb = b;
-
-	if(na->last_successfull_connection == nb->last_successfull_connection) {
-		return 0;
-	}
-
-	if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
-		return -1;
-	}
-
-	if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
-		return 1;
-	}
-
-	if(na < nb) {
-		return -1;
-	}
-
-	if(na > nb) {
-		return 1;
-	}
-
-	return 0;
-}
-
-// devclass desc
-static int node_compare_devclass_desc(const void *a, const void *b) {
-	const node_t *na = a, *nb = b;
-
-	if(na->devclass < nb->devclass) {
-		return -1;
-	}
-
-	if(na->devclass > nb->devclass) {
-		return 1;
-	}
-
-	if(na < nb) {
-		return -1;
-	}
-
-	if(na > nb) {
-		return 1;
-	}
-
-	return 0;
-}
-
-
-/*
-
-autoconnect()
-{
-        timeout = 5
-
-        // find the best one for initial connect
-
-        if cur < min
-                newcon =
-                        first from nodes
-                                where dclass <= my.dclass and !connection and (timestamp - last_retry) > retry_timeout
-                                order by dclass asc, last_connection desc
-                if newcon
-                        timeout = 0
-                        goto connect
-
-
-        // find better nodes to connect to: in case we have less than min connections within [BACKBONE, i] and there are nodes which we are not connected to within the range
-
-        if min <= cur < max
-                j = 0
-                for i = BACKBONE to my.dclass
-                        j += count(from connections where node.dclass = i)
-                        if j < min
-                                newcon =
-                                        first from nodes
-                                                where dclass = i and !connection and (timestamp - last_retry) > retry_timeout
-                                                order by last_connection desc
-                                if newcon
-                                        goto connect
-                        else
-                                break
-
-
-        // heal partitions
-
-        if min <= cur < max
-                newcon =
-                        first from nodes
-                                where dclass <= my.dclass and !reachable and (timestamp - last_retry) > retry_timeout
-                                order by dclass asc, last_connection desc
-                if newcon
-                        goto connect
-
-
-        // connect
-
-connect:
-        if newcon
-                connect newcon
-
-
-        // disconnect outgoing connections in case we have more than min connections within [BACKBONE, i] and there are nodes which we are connected to within the range [i, PORTABLE]
-
-        if min < cur <= max
-                j = 0
-                for i = BACKBONE to my.dclass
-                        j += count(from connections where node.dclass = i)
-                        if min < j
-                                delcon =
-                                        first from nodes
-                                                where dclass >= i and outgoing_connection
-                                                order by dclass desc
-                                if disconnect
-                                        goto disconnect
-                                else
-                                        break
-
-
-        // disconnect connections in case we have more than enough connections
-
-        if max < cur
-                delcon =
-                        first from nodes
-                                where outgoing_connection
-                                order by dclass desc
-                goto disconnect
-
-        // disconnect
-
-disconnect
-        if delcon
-                disconnect delcon
-
-
-        // next iteration
-        next (timeout, autoconnect)
-
-}
-
-*/
-
-
 static void periodic_handler(event_loop_t *loop, void *data) {
 	meshlink_handle_t *mesh = loop->data;
 
@@ -356,246 +176,14 @@ static void periodic_handler(event_loop_t *loop, void *data) {
 
 	/* Check if we need to make or break connections. */
 
-	if(mesh->nodes->count > 1) {
-
-		logger(mesh, MESHLINK_DEBUG, "--- autoconnect begin ---");
-
-		int retry_timeout = min(mesh->nodes->count * default_timeout, 60);
-
-		logger(mesh, MESHLINK_DEBUG, "* devclass = %d", mesh->devclass);
-		logger(mesh, MESHLINK_DEBUG, "* nodes = %d", mesh->nodes->count);
-		logger(mesh, MESHLINK_DEBUG, "* retry_timeout = %d", retry_timeout);
-
-
-		// connect disconnect nodes
-
-		node_t *connect_to = NULL;
-		node_t *disconnect_from = NULL;
-
-
-		// get cur_connects
-
-		unsigned int cur_connects = 0;
-
-		for list_each(connection_t, c, mesh->connections) {
-			if(c->status.active) {
-				cur_connects += 1;
-			}
-		}
-
-		logger(mesh, MESHLINK_DEBUG, "* cur_connects = %d", cur_connects);
-		logger(mesh, MESHLINK_DEBUG, "* outgoings = %d", mesh->outgoings->count);
-
-		// get min_connects and max_connects
-
-		unsigned int min_connects = mesh->dev_class_traits[mesh->devclass].min_connects;
-		unsigned int max_connects = mesh->dev_class_traits[mesh->devclass].max_connects;
-
-		logger(mesh, MESHLINK_DEBUG, "* min_connects = %d", min_connects);
-		logger(mesh, MESHLINK_DEBUG, "* max_connects = %d", max_connects);
-
-		// find the best one for initial connect
-
-		if(cur_connects < min_connects) {
-			splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL);
-
-			for splay_each(node_t, n, mesh->nodes) {
-				logger(mesh, MESHLINK_DEBUG, "* %s->devclass = %d", n->name, n->devclass);
-
-				if(n != mesh->self && n->devclass <= mesh->devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
-					splay_insert(nodes, n);
-				}
-			}
-
-			if(nodes->head) {
-				//timeout = 0;
-				connect_to = (node_t *)nodes->head->data;
-
-				logger(mesh, MESHLINK_DEBUG, "* found best one for initial connect: %s", connect_to->name);
-			} else {
-				logger(mesh, MESHLINK_DEBUG, "* could not find node for initial connect");
-			}
-
-			splay_delete_tree(nodes);
-		}
-
-
-		// find better nodes to connect to
-
-		if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
-			unsigned int connects = 0;
-
-			for(dev_class_t devclass = 0; devclass <= mesh->devclass; ++devclass) {
-				for list_each(connection_t, c, mesh->connections) {
-					if(c->status.active && c->node && c->node->devclass == devclass) {
-						connects += 1;
-					}
-				}
-
-				if(connects < min_connects) {
-					splay_tree_t *nodes = splay_alloc_tree(node_compare_lsc_desc, NULL);
-
-					for splay_each(node_t, n, mesh->nodes) {
-						if(n != mesh->self && n->devclass == devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
-							splay_insert(nodes, n);
-						}
-					}
-
-					if(nodes->head) {
-						logger(mesh, MESHLINK_DEBUG, "* found better node");
-						connect_to = (node_t *)nodes->head->data;
-
-						splay_delete_tree(nodes);
-						break;
-					}
-
-					splay_delete_tree(nodes);
-				} else {
-					break;
-				}
-			}
-
-			if(!connect_to) {
-				logger(mesh, MESHLINK_DEBUG, "* could not find better nodes");
-			}
-		}
-
-
-		// heal partitions
-
-		if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
-			splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL);
-
-			for splay_each(node_t, n, mesh->nodes) {
-				if(n != mesh->self && n->devclass <= mesh->devclass && !n->status.reachable && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
-					splay_insert(nodes, n);
-				}
-			}
-
-			if(nodes->head) {
-				logger(mesh, MESHLINK_DEBUG, "* try to heal partition");
-				connect_to = (node_t *)nodes->head->data;
-			} else {
-				logger(mesh, MESHLINK_DEBUG, "* could not find nodes for partition healing");
-			}
-
-			splay_delete_tree(nodes);
-		}
-
-
-		// perform connect
-
-		if(connect_to && !connect_to->connection) {
-			connect_to->last_connect_try = mesh->loop.now.tv_sec;
-			logger(mesh, MESHLINK_DEBUG, "Autoconnect trying to connect to %s", connect_to->name);
-
-			/* check if there is already a connection attempt to this node */
-			bool skip = false;
-
-			for list_each(outgoing_t, outgoing, mesh->outgoings) {
-				if(outgoing->node == connect_to) {
-					logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since it is an outgoing connection already");
-					skip = true;
-					break;
-				}
-			}
-
-			if(!connect_to->status.reachable && !node_read_public_key(mesh, connect_to)) {
-				logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since we don't know this node's public key");
-				skip = true;
-			}
-
-			if(!skip) {
-				logger(mesh, MESHLINK_DEBUG, "Autoconnecting to %s", connect_to->name);
-				outgoing_t *outgoing = xzalloc(sizeof(outgoing_t));
-				outgoing->node = connect_to;
-				list_insert_tail(mesh->outgoings, outgoing);
-				setup_outgoing_connection(mesh, outgoing);
-			}
-		}
-
-
-		// disconnect suboptimal outgoing connections
-
-		if(min_connects < cur_connects /*&& cur_connects <= max_connects*/) {
-			unsigned int connects = 0;
-
-			for(dev_class_t devclass = 0; devclass <= mesh->devclass; ++devclass) {
-				for list_each(connection_t, c, mesh->connections) {
-					if(c->status.active && c->node && c->node->devclass == devclass) {
-						connects += 1;
-					}
-				}
-
-				if(min_connects < connects) {
-					splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
-
-					for list_each(connection_t, c, mesh->connections) {
-						if(c->outgoing && c->node && c->node->devclass >= devclass) {
-							splay_insert(nodes, c->node);
-						}
-					}
-
-					if(nodes->head) {
-						logger(mesh, MESHLINK_DEBUG, "* disconnect suboptimal outgoing connection");
-						disconnect_from = (node_t *)nodes->head->data;
-					}
-
-					splay_delete_tree(nodes);
-					break;
-				}
-			}
-
-			if(!disconnect_from) {
-				logger(mesh, MESHLINK_DEBUG, "* no suboptimal outgoing connections");
-			}
-		}
-
-
-		// disconnect connections (too many connections)
-
-		if(!disconnect_from && max_connects < cur_connects) {
-			splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
-
-			for list_each(connection_t, c, mesh->connections) {
-				if(c->status.active && c->node) {
-					splay_insert(nodes, c->node);
-				}
-			}
-
-			if(nodes->head) {
-				logger(mesh, MESHLINK_DEBUG, "* disconnect connection (too many connections)");
-
-				//timeout = 0;
-				disconnect_from = (node_t *)nodes->head->data;
-			} else {
-				logger(mesh, MESHLINK_DEBUG, "* no node we want to disconnect, even though we have too many connections");
-			}
-
-			splay_delete_tree(nodes);
-		}
-
-
-		// perform disconnect
-
-		if(disconnect_from && disconnect_from->connection) {
-			logger(mesh, MESHLINK_DEBUG, "Autodisconnecting from %s", disconnect_from->connection->name);
-			list_delete(mesh->outgoings, disconnect_from->connection->outgoing);
-			disconnect_from->connection->outgoing = NULL;
-			terminate_connection(mesh, disconnect_from->connection, disconnect_from->connection->status.active);
-		}
-
-		// reduce timeout if we don't have enough connections + outgoings
-		if(cur_connects + mesh->outgoings->count < 3) {
-			timeout = 1;
-		}
-
-		// done!
-
-		logger(mesh, MESHLINK_DEBUG, "--- autoconnect end ---");
+	if(mesh->peer && !mesh->connection && !mesh->outgoing) {
+		logger(mesh, MESHLINK_DEBUG, "Autoconnecting to %s", mesh->peer->name);
+		mesh->outgoing = xzalloc(sizeof(outgoing_t));
+		mesh->outgoing->node = mesh->peer;
+		setup_outgoing_connection(mesh, mesh->outgoing);
 	}
 
-	for splay_each(node_t, n, mesh->nodes) {
+	for(node_t *n = mesh->peer; n; n = NULL) {
 		if(n->status.dirty) {
 			if(!node_write_config(mesh, n, false)) {
 				logger(mesh, MESHLINK_DEBUG, "Could not update %s", n->name);
@@ -632,7 +220,7 @@ void handle_meta_connection_data(meshlink_handle_t *mesh, connection_t *c) {
 
 void retry(meshlink_handle_t *mesh) {
 	/* Reset the reconnection timers for all outgoing connections */
-	for list_each(outgoing_t, outgoing, mesh->outgoings) {
+	for(outgoing_t *outgoing = mesh->outgoing; outgoing; outgoing = NULL) {
 		outgoing->timeout = 0;
 
 		if(outgoing->ev.cb) {
@@ -644,7 +232,7 @@ void retry(meshlink_handle_t *mesh) {
 
 	/* For active connections, check if their addresses are still valid.
 	 * If yes, reset their ping timers, otherwise terminate them. */
-	for list_each(connection_t, c, mesh->connections) {
+	for(connection_t *c = mesh->connection; c; c = NULL) {
 		if(!c->status.active) {
 			continue;
 		}
diff --git a/src/net_setup.c b/src/net_setup.c
index 4369692..9639280 100644
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -355,13 +355,9 @@ bool setup_network(meshlink_handle_t *mesh) {
   close all open network connections
 */
 void close_network_connections(meshlink_handle_t *mesh) {
-	if(mesh->connections) {
-		for(list_node_t *node = mesh->connections->head, *next; node; node = next) {
-			next = node->next;
-			connection_t *c = node->data;
-			c->outgoing = NULL;
-			terminate_connection(mesh, c, false);
-		}
+	if(mesh->connection) {
+		mesh->connection->outgoing = NULL;
+		terminate_connection(mesh, mesh->connection, false);
 	}
 
 	exit_requests(mesh);
diff --git a/src/net_socket.c b/src/net_socket.c
index fe7bf3a..d4b6208 100644
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -289,6 +289,22 @@ static bool get_next_outgoing_address(meshlink_handle_t *mesh, outgoing_t *outgo
 	return false;
 }
 
+static void free_outgoing(outgoing_t *outgoing) {
+	meshlink_handle_t *mesh = outgoing->node->mesh;
+
+	timeout_del(&mesh->loop, &outgoing->ev);
+
+	if(outgoing->ai) {
+		if(outgoing->state == OUTGOING_RECENT || outgoing->state == OUTGOING_KNOWN) {
+			free_known_addresses(outgoing->ai);
+		} else {
+			freeaddrinfo(outgoing->ai);
+		}
+	}
+
+	free(outgoing);
+}
+
 void do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 begin:
 
@@ -297,7 +313,8 @@ begin:
 			/* We are waiting for a callback from the ADNS thread */
 		} else if(outgoing->state == OUTGOING_NO_KNOWN_ADDRESSES) {
 			logger(mesh, MESHLINK_ERROR, "No known addresses for %s", outgoing->node->name);
-			list_delete(mesh->outgoings, outgoing);
+			free_outgoing(outgoing);
+			mesh->outgoing = NULL;
 		} else {
 			logger(mesh, MESHLINK_ERROR, "Could not set up a meta connection to %s", outgoing->node->name);
 			retry_outgoing(mesh, outgoing);
@@ -409,29 +426,13 @@ void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 	do_outgoing_connection(mesh, outgoing);
 }
 
-static void free_outgoing(outgoing_t *outgoing) {
-	meshlink_handle_t *mesh = outgoing->node->mesh;
-
-	timeout_del(&mesh->loop, &outgoing->ev);
-
-	if(outgoing->ai) {
-		if(outgoing->state == OUTGOING_RECENT || outgoing->state == OUTGOING_KNOWN) {
-			free_known_addresses(outgoing->ai);
-		} else {
-			freeaddrinfo(outgoing->ai);
-		}
-	}
-
-	free(outgoing);
-}
-
 void init_outgoings(meshlink_handle_t *mesh) {
-	mesh->outgoings = list_alloc((list_action_t)free_outgoing);
+	mesh->outgoing = NULL;
 }
 
 void exit_outgoings(meshlink_handle_t *mesh) {
-	if(mesh->outgoings) {
-		list_delete_list(mesh->outgoings);
-		mesh->outgoings = NULL;
+	if(mesh->outgoing) {
+		free_outgoing(mesh->outgoing);
+		mesh->outgoing = NULL;
 	}
 }
diff --git a/src/node.c b/src/node.c
index 160bcb3..1c1c864 100644
--- a/src/node.c
+++ b/src/node.c
@@ -25,24 +25,19 @@
 #include "net.h"
 #include "netutl.h"
 #include "node.h"
-#include "splay_tree.h"
 #include "utils.h"
 #include "xalloc.h"
 
-static int node_compare(const node_t *a, const node_t *b) {
-	return strcmp(a->name, b->name);
-}
-
 void init_nodes(meshlink_handle_t *mesh) {
-	mesh->nodes = splay_alloc_tree((splay_compare_t) node_compare, (splay_action_t) free_node);
+	mesh->peer = NULL;
 }
 
 void exit_nodes(meshlink_handle_t *mesh) {
-	if(mesh->nodes) {
-		splay_delete_tree(mesh->nodes);
+	if(mesh->peer) {
+		free_node(mesh->peer);
 	}
 
-	mesh->nodes = NULL;
+	mesh->peer = NULL;
 }
 
 node_t *new_node(void) {
@@ -76,22 +71,34 @@ void free_node(node_t *n) {
 }
 
 void node_add(meshlink_handle_t *mesh, node_t *n) {
+	if(n == mesh->self) {
+		return;
+	}
+
+	assert(!mesh->peer);
 	n->mesh = mesh;
-	splay_insert(mesh->nodes, n);
+	mesh->peer = n;
 }
 
 void node_del(meshlink_handle_t *mesh, node_t *n) {
+	if(n == mesh->self) {
+		return;
+	}
+
+	assert(mesh->peer && mesh->peer == n);
 	timeout_del(&mesh->loop, &n->mtutimeout);
-	splay_delete(mesh->nodes, n);
+	free_node(n);
+	mesh->peer = NULL;
 }
 
 node_t *lookup_node(meshlink_handle_t *mesh, const char *name) {
-	const node_t n = {.name = (char *)name};
-	node_t *result;
-
-	result = splay_search(mesh->nodes, &n);
-
-	return result;
+	if(mesh->peer && !strcmp(name, mesh->peer->name)) {
+		return mesh->peer;
+	} else if(!strcmp(name, mesh->self->name)) {
+		return mesh->self;
+	} else {
+		return NULL;
+	}
 }
 
 bool node_add_recent_address(meshlink_handle_t *mesh, node_t *n, const sockaddr_t *sa) {
diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index f46a4f4..5ee7a5f 100644
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -173,23 +173,6 @@ bool ack_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
 		n = new_node();
 		n->name = xstrdup(c->name);
 		node_add(mesh, n);
-	} else {
-		if(n->connection) {
-			/* Oh dear, we already have a connection to this node. */
-			logger(mesh, MESHLINK_INFO, "Established a second connection with %s, closing old connection", n->connection->name);
-
-			if(n->connection->outgoing) {
-				if(c->outgoing) {
-					logger(mesh, MESHLINK_WARNING, "Two outgoing connections to the same node!");
-				} else {
-					c->outgoing = n->connection->outgoing;
-				}
-
-				n->connection->outgoing = NULL;
-			}
-
-			terminate_connection(mesh, n->connection, false);
-		}
 	}
 
 	n->devclass = devclass;
@@ -213,25 +196,6 @@ bool ack_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
 		mesh->meta_status_cb(mesh, (meshlink_node_t *)n, true);
 	}
 
-	/*  Terminate any connections to this node that are not activated yet */
-
-	for list_each(connection_t, other, mesh->connections) {
-		if(!other->status.active && !strcmp(other->name, c->name)) {
-			if(other->outgoing) {
-				if(c->outgoing) {
-					logger(mesh, MESHLINK_WARNING, "Two outgoing connections to the same node!");
-				} else {
-					c->outgoing = other->outgoing;
-				}
-
-				other->outgoing = NULL;
-			}
-
-			logger(mesh, MESHLINK_DEBUG, "Terminating pending second connection with %s", n->name);
-			terminate_connection(mesh, other, false);
-		}
-	}
-
 	/* TODO: Create an edge_t for this connection, send it */
 
 	/* Request a session key to jump start UDP traffic */
diff --git a/src/protocol_key.c b/src/protocol_key.c
index de6b1e5..e89f8ec 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -182,10 +182,10 @@ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *
 		}
 
 		/* If we are trying to form an outgoing connection to this node, retry immediately */
-		for list_each(outgoing_t, outgoing, mesh->outgoings) {
-			if(outgoing->node == from && outgoing->ev.cb) {
-				outgoing->timeout = 0;
-				timeout_set(&mesh->loop, &outgoing->ev, &(struct timespec) {
+		if(mesh->outgoing) {
+			if(mesh->outgoing->node == from && mesh->outgoing->ev.cb) {
+				mesh->outgoing->timeout = 0;
+				timeout_set(&mesh->loop, &mesh->outgoing->ev, &(struct timespec) {
 					0, 0
 				});
 			}
-- 
2.39.5