X-Git-Url: http://git.meshlink.io/?p=meshlink;a=blobdiff_plain;f=src%2Fmeshlink.c;h=0843cc0c4826d0d3a800904f28e4c1c51704c528;hp=903ff09a2040049d1b979bf8b3689bcb0ee42657;hb=d1b4e07e76555ecf47faf36f38a62878969be6d7;hpb=d65ff28f38ba779fbd6f970fb3c84b0ed98daa28

diff --git a/src/meshlink.c b/src/meshlink.c
index 903ff09a..0843cc0c 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -20,10 +20,12 @@
 #include "system.h"
 #include <pthread.h>
 
+#include "adns.h"
 #include "crypto.h"
 #include "ecdsagen.h"
 #include "logger.h"
 #include "meshlink_internal.h"
+#include "net.h"
 #include "netutl.h"
 #include "node.h"
 #include "submesh.h"
@@ -152,7 +154,9 @@ static int socket_in_netns(int domain, int type, int protocol, int netns) {
 	pthread_t thr;
 
 	if(pthread_create(&thr, NULL, socket_in_netns_thread, &params) == 0) {
-		pthread_join(thr, NULL);
+		if(pthread_join(thr, NULL) != 0) {
+			abort();
+		}
 	}
 
 	return params.fd;
@@ -165,12 +169,13 @@ static int socket_in_netns(int domain, int type, int protocol, int netns) {
 // Find out what local address a socket would use if we connect to the given address.
 // We do this using connect() on a UDP socket, so the kernel has to resolve the address
 // of both endpoints, but this will actually not send any UDP packet.
-static bool getlocaladdr(char *destaddr, sockaddr_t *sa, socklen_t *salen, int netns) {
+static bool getlocaladdr(const char *destaddr, sockaddr_t *sa, socklen_t *salen, int netns) {
 	struct addrinfo *rai = NULL;
 	const struct addrinfo hint = {
 		.ai_family = AF_UNSPEC,
 		.ai_socktype = SOCK_DGRAM,
 		.ai_protocol = IPPROTO_UDP,
+		.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV,
 	};
 
 	if(getaddrinfo(destaddr, "80", &hint, &rai) || !rai) {
@@ -201,7 +206,7 @@ static bool getlocaladdr(char *destaddr, sockaddr_t *sa, socklen_t *salen, int n
 	return true;
 }
 
-static bool getlocaladdrname(char *destaddr, char *host, socklen_t hostlen, int netns) {
+static bool getlocaladdrname(const char *destaddr, char *host, socklen_t hostlen, int netns) {
 	sockaddr_t sa;
 	socklen_t salen = sizeof(sa);
 
@@ -221,12 +226,42 @@ char *meshlink_get_external_address(meshlink_handle_t *mesh) {
 }
 
 char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int family) {
-	char *hostname = NULL;
+	const char *url = mesh->external_address_url;
+
+	if(!url) {
+		url = "http://meshlink.io/host.cgi";
+	}
+
+	/* Find the hostname part between the slashes */
+	if(strncmp(url, "http://", 7)) {
+		abort();
+		meshlink_errno = MESHLINK_EINTERNAL;
+		return NULL;
+	}
+
+	const char *begin = url + 7;
+
+	const char *end = strchr(begin, '/');
+
+	if(!end) {
+		end = begin + strlen(begin);
+	}
+
+	/* Make a copy */
+	char host[end - begin + 1];
+	strncpy(host, begin, end - begin);
+	host[end - begin] = 0;
+
+	char *port = strchr(host, ':');
+
+	if(port) {
+		*port++ = 0;
+	}
 
 	logger(mesh, MESHLINK_DEBUG, "Trying to discover externally visible hostname...\n");
-	struct addrinfo *ai = str2addrinfo("meshlink.io", "80", SOCK_STREAM);
-	static const char request[] = "GET http://www.meshlink.io/host.cgi HTTP/1.0\r\n\r\n";
+	struct addrinfo *ai = adns_blocking_request(mesh, xstrdup(host), xstrdup(port ? port : "80"), SOCK_STREAM, 5);
 	char line[256];
+	char *hostname = NULL;
 
 	for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 		if(family != AF_UNSPEC && aip->ai_family != family) {
@@ -235,6 +270,11 @@ char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int fami
 
 		int s = socket_in_netns(aip->ai_family, aip->ai_socktype, aip->ai_protocol, mesh->netns);
 
+#ifdef SO_NOSIGPIPE
+		int nosigpipe = 1;
+		setsockopt(s, SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe, sizeof(nosigpipe));
+#endif
+
 		if(s >= 0) {
 			set_timeout(s, 5000);
 
@@ -245,7 +285,9 @@ char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int fami
 		}
 
 		if(s >= 0) {
-			send(s, request, sizeof(request) - 1, 0);
+			send(s, "GET ", 4, 0);
+			send(s, url, strlen(url), 0);
+			send(s, " HTTP/1.0\r\n\r\n", 13, 0);
 			int len = recv(s, line, sizeof(line) - 1, MSG_WAITALL);
 
 			if(len > 0) {
@@ -302,6 +344,52 @@ static bool is_localaddr(sockaddr_t *sa) {
 	}
 }
 
+#ifdef HAVE_GETIFADDRS
+struct getifaddrs_in_netns_params {
+	struct ifaddrs **ifa;
+	int netns;
+};
+
+#ifdef HAVE_SETNS
+static void *getifaddrs_in_netns_thread(void *arg) {
+	struct getifaddrs_in_netns_params *params = arg;
+
+	if(setns(params->netns, CLONE_NEWNET) == -1) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(getifaddrs(params->ifa) != 0) {
+		*params->ifa = NULL;
+	}
+
+	return NULL;
+}
+#endif // HAVE_SETNS
+
+static int getifaddrs_in_netns(struct ifaddrs **ifa, int netns) {
+	if(netns == -1) {
+		return getifaddrs(ifa);
+	}
+
+#ifdef HAVE_SETNS
+	struct getifaddrs_in_netns_params params = {ifa, netns};
+	pthread_t thr;
+
+	if(pthread_create(&thr, NULL, getifaddrs_in_netns_thread, &params) == 0) {
+		if(pthread_join(thr, NULL) != 0) {
+			abort();
+		}
+	}
+
+	return *params.ifa ? 0 : -1;
+#else
+	return -1;
+#endif // HAVE_SETNS
+
+}
+#endif
+
 char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int family) {
 	(void)mesh;
 
@@ -319,12 +407,12 @@ char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int family)
 
 	if(!success) {
 		struct ifaddrs *ifa = NULL;
-		getifaddrs(&ifa);
+		getifaddrs_in_netns(&ifa, mesh->netns);
 
 		for(struct ifaddrs *ifap = ifa; ifap; ifap = ifap->ifa_next) {
 			sockaddr_t *sa = (sockaddr_t *)ifap->ifa_addr;
 
-			if(sa->sa.sa_family != family) {
+			if(!sa || sa->sa.sa_family != family) {
 				continue;
 			}
 
@@ -351,7 +439,7 @@ char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int family)
 	return xstrdup(localaddr);
 }
 
-void remove_duplicate_hostnames(char *host[], char *port[], int n) {
+static void remove_duplicate_hostnames(char *host[], char *port[], int n) {
 	for(int i = 0; i < n; i++) {
 		if(!host[i]) {
 			continue;
@@ -389,10 +477,15 @@ void remove_duplicate_hostnames(char *host[], char *port[], int n) {
 
 // This gets the hostname part for use in invitation URLs
 static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
-	char *hostname[4] = {NULL};
-	char *port[4] = {NULL};
+	int count = 4 + (mesh->invitation_addresses ? mesh->invitation_addresses->count : 0);
+	int n = 0;
+	char *hostname[count];
+	char *port[count];
 	char *hostport = NULL;
 
+	memset(hostname, 0, sizeof(hostname));
+	memset(port, 0, sizeof(port));
+
 	if(!(flags & (MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC))) {
 		flags |= MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC;
 	}
@@ -401,109 +494,86 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
 		flags |= MESHLINK_INVITE_IPV4 | MESHLINK_INVITE_IPV6;
 	}
 
+	// Add all explicitly set invitation addresses
+	if(mesh->invitation_addresses) {
+		for list_each(char, combo, mesh->invitation_addresses) {
+			hostname[n] = xstrdup(combo);
+			char *slash = strrchr(hostname[n], '/');
+
+			if(slash) {
+				*slash = 0;
+				port[n] = xstrdup(slash + 1);
+			}
+
+			n++;
+		}
+	}
+
 	// Add local addresses if requested
 	if(flags & MESHLINK_INVITE_LOCAL) {
 		if(flags & MESHLINK_INVITE_IPV4) {
-			hostname[0] = meshlink_get_local_address_for_family(mesh, AF_INET);
+			hostname[n++] = meshlink_get_local_address_for_family(mesh, AF_INET);
 		}
 
 		if(flags & MESHLINK_INVITE_IPV6) {
-			hostname[1] = meshlink_get_local_address_for_family(mesh, AF_INET6);
+			hostname[n++] = meshlink_get_local_address_for_family(mesh, AF_INET6);
 		}
 	}
 
 	// Add public/canonical addresses if requested
 	if(flags & MESHLINK_INVITE_PUBLIC) {
 		// Try the CanonicalAddress first
-		get_canonical_address(mesh->self, &hostname[2], &port[2]);
+		get_canonical_address(mesh->self, &hostname[n], &port[n]);
 
-		if(!hostname[2]) {
+		if(!hostname[n] && count == 4) {
 			if(flags & MESHLINK_INVITE_IPV4) {
-				hostname[2] = meshlink_get_external_address_for_family(mesh, AF_INET);
+				hostname[n++] = meshlink_get_external_address_for_family(mesh, AF_INET);
 			}
 
 			if(flags & MESHLINK_INVITE_IPV6) {
-				hostname[3] = meshlink_get_external_address_for_family(mesh, AF_INET6);
+				hostname[n++] = meshlink_get_external_address_for_family(mesh, AF_INET6);
 			}
+		} else {
+			n++;
 		}
 	}
 
-	for(int i = 0; i < 4; i++) {
+	for(int i = 0; i < n; i++) {
 		// Ensure we always have a port number
 		if(hostname[i] && !port[i]) {
 			port[i] = xstrdup(mesh->myport);
 		}
 	}
 
-	remove_duplicate_hostnames(hostname, port, 4);
+	remove_duplicate_hostnames(hostname, port, n);
 
 	// Resolve the hostnames
-	for(int i = 0; i < 4; i++) {
+	for(int i = 0; i < n; i++) {
 		if(!hostname[i]) {
 			continue;
 		}
 
 		// Convert what we have to a sockaddr
-		struct addrinfo *ai_in, *ai_out;
-		struct addrinfo hint = {
-			.ai_family = AF_UNSPEC,
-			.ai_flags = AI_NUMERICSERV,
-			.ai_socktype = SOCK_STREAM,
-		};
-		int err = getaddrinfo(hostname[i], port[i], &hint, &ai_in);
-
-		if(err || !ai_in) {
-			continue;
-		}
-
-		// Remember the address
-		node_add_recent_address(mesh, mesh->self, (sockaddr_t *)ai_in->ai_addr);
-
-		if(flags & MESHLINK_INVITE_NUMERIC) {
-			// We don't need to do any further conversion
-			freeaddrinfo(ai_in);
-			continue;
-		}
-
-		// Convert it to a hostname
-		char resolved_host[NI_MAXHOST];
-		char resolved_port[NI_MAXSERV];
-		err = getnameinfo(ai_in->ai_addr, ai_in->ai_addrlen, resolved_host, sizeof resolved_host, resolved_port, sizeof resolved_port, NI_NUMERICSERV);
+		struct addrinfo *ai_in = adns_blocking_request(mesh, xstrdup(hostname[i]), xstrdup(port[i]), SOCK_STREAM, 5);
 
-		if(err || !is_valid_hostname(resolved_host)) {
-			freeaddrinfo(ai_in);
+		if(!ai_in) {
 			continue;
 		}
 
-		// Convert the hostname back to a sockaddr
-		hint.ai_family = ai_in->ai_family;
-		err = getaddrinfo(resolved_host, resolved_port, &hint, &ai_out);
-
-		if(err || !ai_out) {
-			freeaddrinfo(ai_in);
-			continue;
-		}
-
-		// Check if it's still the same sockaddr
-		if(ai_in->ai_addrlen != ai_out->ai_addrlen || memcmp(ai_in->ai_addr, ai_out->ai_addr, ai_in->ai_addrlen)) {
-			freeaddrinfo(ai_in);
-			freeaddrinfo(ai_out);
-			continue;
+		// Remember the address(es)
+		for(struct addrinfo *aip = ai_in; aip; aip = aip->ai_next) {
+			node_add_recent_address(mesh, mesh->self, (sockaddr_t *)aip->ai_addr);
 		}
 
-		// Yes: replace the hostname with the resolved one
-		free(hostname[i]);
-		hostname[i] = xstrdup(resolved_host);
-
 		freeaddrinfo(ai_in);
-		freeaddrinfo(ai_out);
+		continue;
 	}
 
 	// Remove duplicates again, since IPv4 and IPv6 addresses might map to the same hostname
-	remove_duplicate_hostnames(hostname, port, 4);
+	remove_duplicate_hostnames(hostname, port, n);
 
 	// Concatenate all unique address to the hostport string
-	for(int i = 0; i < 4; i++) {
+	for(int i = 0; i < n; i++) {
 		if(!hostname[i]) {
 			continue;
 		}
@@ -521,7 +591,7 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
 	return hostport;
 }
 
-static bool try_bind(int port) {
+static bool try_bind(meshlink_handle_t *mesh, int port) {
 	struct addrinfo *ai = NULL;
 	struct addrinfo hint = {
 		.ai_flags = AI_PASSIVE,
@@ -537,33 +607,47 @@ static bool try_bind(int port) {
 		return false;
 	}
 
-	//while(ai) {
+	bool success = false;
+
 	for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
-		int fd = socket(aip->ai_family, SOCK_STREAM, IPPROTO_TCP);
+		/* Try to bind to TCP. */
 
-		if(!fd) {
-			freeaddrinfo(ai);
-			return false;
+		int tcp_fd = setup_tcp_listen_socket(mesh, aip);
+
+		if(tcp_fd == -1) {
+			if(errno == EADDRINUSE) {
+				/* If this port is in use for any address family, avoid it. */
+				success = false;
+				break;
+			} else {
+				continue;
+			}
 		}
 
-		int result = bind(fd, aip->ai_addr, aip->ai_addrlen);
-		closesocket(fd);
+		/* If TCP worked, then we require that UDP works as well. */
 
-		if(result) {
-			freeaddrinfo(ai);
-			return false;
+		int udp_fd = setup_udp_listen_socket(mesh, aip);
+
+		if(udp_fd == -1) {
+			closesocket(tcp_fd);
+			success = false;
+			break;
 		}
+
+		closesocket(tcp_fd);
+		closesocket(udp_fd);
+		success = true;
 	}
 
 	freeaddrinfo(ai);
-	return true;
+	return success;
 }
 
-static int check_port(meshlink_handle_t *mesh) {
+int check_port(meshlink_handle_t *mesh) {
 	for(int i = 0; i < 1000; i++) {
 		int port = 0x1000 + prng(mesh, 0x8000);
 
-		if(try_bind(port)) {
+		if(try_bind(mesh, port)) {
 			free(mesh->myport);
 			xasprintf(&mesh->myport, "%d", port);
 			return port;
@@ -634,24 +718,28 @@ static bool finalize_join(join_state_t *state, const void *buf, uint16_t len) {
 	}
 
 	char *name = packmsg_get_str_dup(&in);
-	packmsg_skip_element(&in); /* submesh */
+	char *submesh_name = packmsg_get_str_dup(&in);
 	dev_class_t devclass = packmsg_get_int32(&in);
 	uint32_t count = packmsg_get_array(&in);
 
-	if(!name) {
-		logger(mesh, MESHLINK_DEBUG, "No Name found in invitation!\n");
+	if(!name || !check_id(name)) {
+		logger(mesh, MESHLINK_DEBUG, "No valid Name found in invitation!\n");
+		free(name);
+		free(submesh_name);
 		return false;
 	}
 
-	if(!check_id(name)) {
-		logger(mesh, MESHLINK_DEBUG, "Invalid Name found in invitation: %s!\n", name);
+	if(!submesh_name || (strcmp(submesh_name, CORE_MESH) && !check_id(submesh_name))) {
+		logger(mesh, MESHLINK_DEBUG, "No valid Submesh found in invitation!\n");
 		free(name);
+		free(submesh_name);
 		return false;
 	}
 
 	if(!count) {
 		logger(mesh, MESHLINK_ERROR, "Incomplete invitation file!\n");
 		free(name);
+		free(submesh_name);
 		return false;
 	}
 
@@ -659,6 +747,8 @@ static bool finalize_join(join_state_t *state, const void *buf, uint16_t len) {
 	free(mesh->self->name);
 	mesh->name = name;
 	mesh->self->name = xstrdup(name);
+	mesh->self->submesh = strcmp(submesh_name, CORE_MESH) ? lookup_or_create_submesh(mesh, submesh_name) : NULL;
+	free(submesh_name);
 	mesh->self->devclass = devclass == DEV_CLASS_UNKNOWN ? mesh->devclass : devclass;
 
 	// Initialize configuration directory
@@ -673,39 +763,39 @@ static bool finalize_join(join_state_t *state, const void *buf, uint16_t len) {
 	// Write host config files
 	for(uint32_t i = 0; i < count; i++) {
 		const void *data;
-		uint32_t len = packmsg_get_bin_raw(&in, &data);
+		uint32_t data_len = packmsg_get_bin_raw(&in, &data);
 
-		if(!len) {
+		if(!data_len) {
 			logger(mesh, MESHLINK_ERROR, "Incomplete invitation file!\n");
 			return false;
 		}
 
-		packmsg_input_t in2 = {data, len};
-		uint32_t version = packmsg_get_uint32(&in2);
-		char *name = packmsg_get_str_dup(&in2);
+		packmsg_input_t in2 = {data, data_len};
+		uint32_t version2 = packmsg_get_uint32(&in2);
+		char *name2 = packmsg_get_str_dup(&in2);
 
-		if(!packmsg_input_ok(&in2) || version != MESHLINK_CONFIG_VERSION || !check_id(name)) {
-			free(name);
+		if(!packmsg_input_ok(&in2) || version2 != MESHLINK_CONFIG_VERSION || !check_id(name2)) {
+			free(name2);
 			packmsg_input_invalidate(&in);
 			break;
 		}
 
-		if(!check_id(name)) {
-			free(name);
+		if(!check_id(name2)) {
+			free(name2);
 			break;
 		}
 
-		if(!strcmp(name, mesh->name)) {
+		if(!strcmp(name2, mesh->name)) {
 			logger(mesh, MESHLINK_DEBUG, "Secondary chunk would overwrite our own host config file.\n");
-			free(name);
+			free(name2);
 			meshlink_errno = MESHLINK_EPEER;
 			return false;
 		}
 
 		node_t *n = new_node();
-		n->name = name;
+		n->name = name2;
 
-		config_t config = {data, len};
+		config_t config = {data, data_len};
 
 		if(!node_read_from_config(mesh, n, &config)) {
 			free_node(n);
@@ -739,10 +829,14 @@ static bool finalize_join(join_state_t *state, const void *buf, uint16_t len) {
 	}
 
 	/* Ensure the configuration directory metadata is on disk */
-	if(!config_sync(mesh, "current") || !sync_path(mesh->confbase)) {
+	if(!config_sync(mesh, "current") || (mesh->confbase && !sync_path(mesh->confbase))) {
 		return false;
 	}
 
+	if(!mesh->inviter_commits_first) {
+		devtool_set_inviter_commits_first(false);
+	}
+
 	sptps_send_record(&state->sptps, 1, ecdsa_get_public_key(mesh->private_key), 32);
 
 	logger(mesh, MESHLINK_DEBUG, "Configuration stored in: %s\n", mesh->confbase);
@@ -847,7 +941,7 @@ static bool recvline(join_state_t *state) {
 	return true;
 }
 
-static bool sendline(int fd, char *format, ...) {
+static bool sendline(int fd, const char *format, ...) {
 	char buffer[4096];
 	char *p = buffer;
 	int blen = 0;
@@ -921,10 +1015,18 @@ static bool ecdsa_keygen(meshlink_handle_t *mesh) {
 	return true;
 }
 
-static struct timeval idle(event_loop_t *loop, void *data) {
+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 timeval t, tmin = {3600, 0};
+	struct timespec t, tmin = {3600, 0};
 
 	for splay_each(node_t, n, mesh->nodes) {
 		if(!n->utcp) {
@@ -933,7 +1035,7 @@ static struct timeval idle(event_loop_t *loop, void *data) {
 
 		t = utcp_timeout(n->utcp);
 
-		if(timercmp(&t, &tmin, <)) {
+		if(timespec_lt(&t, &tmin)) {
 			tmin = t;
 		}
 	}
@@ -1040,9 +1142,6 @@ static bool meshlink_read_config(meshlink_handle_t *mesh) {
 		return false;
 	}
 
-#if 0
-
-	// TODO: check this?
 	if(mesh->name && strcmp(mesh->name, name)) {
 		logger(NULL, MESHLINK_ERROR, "Configuration is for a different name (%s)!", name);
 		meshlink_errno = MESHLINK_ESTORAGE;
@@ -1051,8 +1150,6 @@ static bool meshlink_read_config(meshlink_handle_t *mesh) {
 		return false;
 	}
 
-#endif
-
 	free(mesh->name);
 	mesh->name = name;
 	xasprintf(&mesh->myport, "%u", myport);
@@ -1087,7 +1184,6 @@ static void *setup_network_in_netns_thread(void *arg) {
 	}
 
 	bool success = setup_network(mesh);
-	add_local_addresses(mesh);
 	return success ? arg : NULL;
 }
 #endif // HAVE_SETNS
@@ -1111,13 +1207,7 @@ meshlink_open_params_t *meshlink_open_params_init(const char *confbase, const ch
 		return NULL;
 	}
 
-	if(!name || !*name) {
-		logger(NULL, MESHLINK_ERROR, "No name given!\n");
-		meshlink_errno = MESHLINK_EINVAL;
-		return NULL;
-	};
-
-	if(!check_id(name)) {
+	if(name && !check_id(name)) {
 		logger(NULL, MESHLINK_ERROR, "Invalid name given!\n");
 		meshlink_errno = MESHLINK_EINVAL;
 		return NULL;
@@ -1132,7 +1222,7 @@ meshlink_open_params_t *meshlink_open_params_init(const char *confbase, const ch
 	meshlink_open_params_t *params = xzalloc(sizeof * params);
 
 	params->confbase = xstrdup(confbase);
-	params->name = xstrdup(name);
+	params->name = name ? xstrdup(name) : NULL;
 	params->appname = xstrdup(appname);
 	params->devclass = devclass;
 	params->netns = -1;
@@ -1176,7 +1266,9 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	// Create hash for the new key
 	void *new_config_key;
@@ -1254,10 +1346,10 @@ void meshlink_open_params_free(meshlink_open_params_t *params) {
 
 /// Device class traits
 static const dev_class_traits_t default_class_traits[DEV_CLASS_COUNT] = {
-	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 3, .max_connects = 10000, .edge_weight = 1 }, // DEV_CLASS_BACKBONE
-	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 3, .max_connects = 100, .edge_weight = 3 },   // DEV_CLASS_STATIONARY
-	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 3, .max_connects = 3, .edge_weight = 6 },     // DEV_CLASS_PORTABLE
-	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 1, .max_connects = 1, .edge_weight = 9 },     // DEV_CLASS_UNKNOWN
+	{ .pingtimeout = 5, .pinginterval = 60, .maxtimeout = 900, .min_connects = 3, .max_connects = 10000, .edge_weight = 1 }, // DEV_CLASS_BACKBONE
+	{ .pingtimeout = 5, .pinginterval = 60, .maxtimeout = 900, .min_connects = 3, .max_connects = 100, .edge_weight = 3 },   // DEV_CLASS_STATIONARY
+	{ .pingtimeout = 5, .pinginterval = 60, .maxtimeout = 900, .min_connects = 3, .max_connects = 3, .edge_weight = 6 },     // DEV_CLASS_PORTABLE
+	{ .pingtimeout = 5, .pinginterval = 60, .maxtimeout = 900, .min_connects = 1, .max_connects = 1, .edge_weight = 9 },     // DEV_CLASS_UNKNOWN
 };
 
 meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
@@ -1305,6 +1397,36 @@ meshlink_handle_t *meshlink_open_encrypted(const char *confbase, const char *nam
 }
 
 meshlink_handle_t *meshlink_open_ephemeral(const char *name, const char *appname, dev_class_t devclass) {
+	if(!name) {
+		logger(NULL, MESHLINK_ERROR, "No name given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(!check_id(name)) {
+		logger(NULL, MESHLINK_ERROR, "Invalid name given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(!appname || !*appname) {
+		logger(NULL, MESHLINK_ERROR, "No appname given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(strchr(appname, ' ')) {
+		logger(NULL, MESHLINK_ERROR, "Invalid appname given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(devclass < 0 || devclass >= DEV_CLASS_COUNT) {
+		logger(NULL, MESHLINK_ERROR, "Invalid devclass given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
 	/* Create a temporary struct on the stack, to avoid allocating and freeing one. */
 	meshlink_open_params_t params;
 	memset(&params, 0, sizeof(params));
@@ -1318,11 +1440,9 @@ meshlink_handle_t *meshlink_open_ephemeral(const char *name, const char *appname
 }
 
 meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
-	// Validate arguments provided by the application
-	bool usingname = false;
-
 	logger(NULL, MESHLINK_DEBUG, "meshlink_open called\n");
 
+	// Validate arguments provided by the application
 	if(!params->appname || !*params->appname) {
 		logger(NULL, MESHLINK_ERROR, "No appname given!\n");
 		meshlink_errno = MESHLINK_EINVAL;
@@ -1335,18 +1455,10 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 		return NULL;
 	}
 
-	if(!params->name || !*params->name) {
-		logger(NULL, MESHLINK_ERROR, "No name given!\n");
-		//return NULL;
-	} else { //check name only if there is a name != NULL
-
-		if(!check_id(params->name)) {
-			logger(NULL, MESHLINK_ERROR, "Invalid name given!\n");
-			meshlink_errno = MESHLINK_EINVAL;
-			return NULL;
-		} else {
-			usingname = true;
-		}
+	if(params->name && !check_id(params->name)) {
+		logger(NULL, MESHLINK_ERROR, "Invalid name given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
 	}
 
 	if(params->devclass < 0 || params->devclass >= DEV_CLASS_COUNT) {
@@ -1375,6 +1487,7 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 	mesh->submeshes = NULL;
 	mesh->log_cb = global_log_cb;
 	mesh->log_level = global_log_level;
+	mesh->packet = xmalloc(sizeof(vpn_packet_t));
 
 	randomize(&mesh->prng_state, sizeof(mesh->prng_state));
 
@@ -1384,9 +1497,7 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 
 	memcpy(mesh->dev_class_traits, default_class_traits, sizeof(default_class_traits));
 
-	if(usingname) {
-		mesh->name = xstrdup(params->name);
-	}
+	mesh->name = params->name ? xstrdup(params->name) : NULL;
 
 	// Hash the key
 	if(params->key) {
@@ -1400,11 +1511,21 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 		}
 	}
 
-	// initialize mutex
+	// initialize mutexes and conds
 	pthread_mutexattr_t attr;
 	pthread_mutexattr_init(&attr);
-	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+
+	if(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) != 0) {
+		abort();
+	}
+
 	pthread_mutex_init(&mesh->mutex, &attr);
+	pthread_cond_init(&mesh->cond, NULL);
+
+	pthread_mutex_init(&mesh->discovery_mutex, NULL);
+	pthread_cond_init(&mesh->discovery_cond, NULL);
+
+	pthread_cond_init(&mesh->adns_cond, NULL);
 
 	mesh->threadstarted = false;
 	event_loop_init(&mesh->loop);
@@ -1421,6 +1542,13 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 	// If no configuration exists yet, create it.
 
 	if(!meshlink_confbase_exists(mesh)) {
+		if(!mesh->name) {
+			logger(NULL, MESHLINK_ERROR, "No configuration files found!\n");
+			meshlink_close(mesh);
+			meshlink_errno = MESHLINK_ESTORAGE;
+			return NULL;
+		}
+
 		if(!meshlink_setup(mesh)) {
 			logger(NULL, MESHLINK_ERROR, "Cannot create initial configuration\n");
 			meshlink_close(mesh);
@@ -1460,7 +1588,6 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 #endif // HAVE_SETNS
 	} else {
 		success = setup_network(mesh);
-		add_local_addresses(mesh);
 	}
 
 	if(!success) {
@@ -1498,7 +1625,9 @@ meshlink_submesh_t *meshlink_submesh_open(meshlink_handle_t  *mesh, const char *
 	}
 
 	//lock mesh->nodes
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	s = (meshlink_submesh_t *)create_submesh(mesh, submesh);
 
@@ -1532,7 +1661,9 @@ static void *meshlink_main_loop(void *arg) {
 
 #endif
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	logger(mesh, MESHLINK_DEBUG, "Starting main_loop...\n");
 	pthread_cond_broadcast(&mesh->cond);
@@ -1554,9 +1685,6 @@ static void *meshlink_main_loop(void *arg) {
 }
 
 bool meshlink_start(meshlink_handle_t *mesh) {
-	assert(mesh->self);
-	assert(mesh->private_key);
-
 	if(!mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
@@ -1564,8 +1692,12 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	logger(mesh, MESHLINK_DEBUG, "meshlink_start called\n");
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
+	assert(mesh->self);
+	assert(mesh->private_key);
 	assert(mesh->self->ecdsa);
 	assert(!memcmp((uint8_t *)mesh->self->ecdsa + 64, (uint8_t *)mesh->private_key + 64, 32));
 
@@ -1581,6 +1713,11 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 		return false;
 	}
 
+	// Reset node connection timers
+	for splay_each(node_t, n, mesh->nodes) {
+		n->last_connect_try = 0;
+	}
+
 	// TODO: open listening sockets first
 
 	//Check that a valid name is set
@@ -1592,12 +1729,18 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 	}
 
 	init_outgoings(mesh);
+	init_adns(mesh);
 
 	// Start the main thread
 
 	event_loop_start(&mesh->loop);
 
-	if(pthread_create(&mesh->thread, NULL, meshlink_main_loop, mesh) != 0) {
+	// Ensure we have a decent amount of stack space. Musl's default of 80 kB is too small.
+	pthread_attr_t attr;
+	pthread_attr_init(&attr);
+	pthread_attr_setstacksize(&attr, 1024 * 1024);
+
+	if(pthread_create(&mesh->thread, &attr, meshlink_main_loop, mesh) != 0) {
 		logger(mesh, MESHLINK_DEBUG, "Could not start thread: %s\n", strerror(errno));
 		memset(&mesh->thread, 0, sizeof(mesh)->thread);
 		meshlink_errno = MESHLINK_EINTERNAL;
@@ -1622,7 +1765,10 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	logger(mesh, MESHLINK_DEBUG, "meshlink_stop called\n");
 
 	// Shut down the main thread
@@ -1646,8 +1792,14 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 	if(mesh->threadstarted) {
 		// Wait for the main thread to finish
 		pthread_mutex_unlock(&mesh->mutex);
-		pthread_join(mesh->thread, NULL);
-		pthread_mutex_lock(&mesh->mutex);
+
+		if(pthread_join(mesh->thread, NULL) != 0) {
+			abort();
+		}
+
+		if(pthread_mutex_lock(&mesh->mutex) != 0) {
+			abort();
+		}
 
 		mesh->threadstarted = false;
 	}
@@ -1662,6 +1814,7 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		}
 	}
 
+	exit_adns(mesh);
 	exit_outgoings(mesh);
 
 	// Ensure we are considered unreachable
@@ -1691,7 +1844,9 @@ void meshlink_close(meshlink_handle_t *mesh) {
 	meshlink_stop(mesh);
 
 	// lock is not released after this
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	// Close and free all resources used.
 
@@ -1725,8 +1880,14 @@ void meshlink_close(meshlink_handle_t *mesh) {
 	free(mesh->appname);
 	free(mesh->confbase);
 	free(mesh->config_key);
+	free(mesh->external_address_url);
+	free(mesh->packet);
 	ecdsa_free(mesh->private_key);
 
+	if(mesh->invitation_addresses) {
+		list_delete_list(mesh->invitation_addresses);
+	}
+
 	main_config_unlock(mesh);
 
 	pthread_mutex_unlock(&mesh->mutex);
@@ -1806,7 +1967,10 @@ void meshlink_set_receive_cb(meshlink_handle_t *mesh, meshlink_receive_cb_t cb)
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->receive_cb = cb;
 	pthread_mutex_unlock(&mesh->mutex);
 }
@@ -1817,7 +1981,10 @@ void meshlink_set_connection_try_cb(meshlink_handle_t *mesh, meshlink_connection
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->connection_try_cb = cb;
 	pthread_mutex_unlock(&mesh->mutex);
 }
@@ -1828,7 +1995,10 @@ void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->node_status_cb = cb;
 	pthread_mutex_unlock(&mesh->mutex);
 }
@@ -1839,7 +2009,10 @@ void meshlink_set_node_pmtu_cb(meshlink_handle_t *mesh, meshlink_node_pmtu_cb_t
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->node_pmtu_cb = cb;
 	pthread_mutex_unlock(&mesh->mutex);
 }
@@ -1850,14 +2023,20 @@ void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_dupli
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->node_duplicate_cb = cb;
 	pthread_mutex_unlock(&mesh->mutex);
 }
 
 void meshlink_set_log_cb(meshlink_handle_t *mesh, meshlink_log_level_t level, meshlink_log_cb_t cb) {
 	if(mesh) {
-		pthread_mutex_lock(&mesh->mutex);
+		if(pthread_mutex_lock(&mesh->mutex) != 0) {
+			abort();
+		}
+
 		mesh->log_cb = cb;
 		mesh->log_level = cb ? level : 0;
 		pthread_mutex_unlock(&mesh->mutex);
@@ -1873,25 +2052,18 @@ void meshlink_set_error_cb(struct meshlink_handle *mesh, meshlink_error_cb_t cb)
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->error_cb = cb;
 	pthread_mutex_unlock(&mesh->mutex);
 }
 
-bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len) {
+static bool prepare_packet(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len, vpn_packet_t *packet) {
 	meshlink_packethdr_t *hdr;
 
-	// Validate arguments
-	if(!mesh || !destination || len >= MAXSIZE - sizeof(*hdr)) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return false;
-	}
-
-	if(!len) {
-		return true;
-	}
-
-	if(!data) {
+	if(len > MAXSIZE - sizeof(*hdr)) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
@@ -1905,13 +2077,6 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 	}
 
 	// Prepare the packet
-	vpn_packet_t *packet = malloc(sizeof(*packet));
-
-	if(!packet) {
-		meshlink_errno = MESHLINK_ENOMEM;
-		return false;
-	}
-
 	packet->probe = false;
 	packet->tcp = false;
 	packet->len = len + sizeof(*hdr);
@@ -1920,38 +2085,88 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 	memset(hdr, 0, sizeof(*hdr));
 	// leave the last byte as 0 to make sure strings are always
 	// null-terminated if they are longer than the buffer
-	strncpy((char *)hdr->destination, destination->name, (sizeof(hdr)->destination) - 1);
-	strncpy((char *)hdr->source, mesh->self->name, (sizeof(hdr)->source) - 1);
+	strncpy((char *)hdr->destination, destination->name, sizeof(hdr->destination) - 1);
+	strncpy((char *)hdr->source, mesh->self->name, sizeof(hdr->source) - 1);
 
 	memcpy(packet->data + sizeof(*hdr), data, len);
 
-	// Queue it
-	if(!meshlink_queue_push(&mesh->outpacketqueue, packet)) {
-		free(packet);
-		meshlink_errno = MESHLINK_ENOMEM;
+	return true;
+}
+
+static bool meshlink_send_immediate(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len) {
+	assert(mesh);
+	assert(destination);
+	assert(data);
+	assert(len);
+
+	// Prepare the packet
+	if(!prepare_packet(mesh, destination, data, len, mesh->packet)) {
 		return false;
 	}
 
-	// Notify event loop
-	signal_trigger(&mesh->loop, &mesh->datafromapp);
+	// Send it immediately
+	route(mesh, mesh->self, mesh->packet);
 
 	return true;
 }
 
-void meshlink_send_from_queue(event_loop_t *loop, void *data) {
-	(void)loop;
-	meshlink_handle_t *mesh = data;
-	vpn_packet_t *packet = meshlink_queue_pop(&mesh->outpacketqueue);
+bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len) {
+	// Validate arguments
+	if(!mesh || !destination) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(!len) {
+		return true;
+	}
+
+	if(!data) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	// Prepare the packet
+	vpn_packet_t *packet = malloc(sizeof(*packet));
 
 	if(!packet) {
-		return;
+		meshlink_errno = MESHLINK_ENOMEM;
+		return false;
 	}
 
-	mesh->self->in_packets++;
-	mesh->self->in_bytes += packet->len;
-	route(mesh, mesh->self, packet);
+	if(!prepare_packet(mesh, destination, data, len, packet)) {
+		free(packet);
+		return false;
+	}
+
+	// Queue it
+	if(!meshlink_queue_push(&mesh->outpacketqueue, packet)) {
+		free(packet);
+		meshlink_errno = MESHLINK_ENOMEM;
+		return false;
+	}
+
+	logger(mesh, MESHLINK_DEBUG, "Adding packet of %zu bytes to packet queue", len);
+
+	// Notify event loop
+	signal_trigger(&mesh->loop, &mesh->datafromapp);
+
+	return true;
+}
+
+void meshlink_send_from_queue(event_loop_t *loop, void *data) {
+	(void)loop;
+	meshlink_handle_t *mesh = data;
+
+	logger(mesh, MESHLINK_DEBUG, "Flushing the packet queue");
 
-	free(packet);
+	for(vpn_packet_t *packet; (packet = meshlink_queue_pop(&mesh->outpacketqueue));) {
+		logger(mesh, MESHLINK_DEBUG, "Removing packet of %d bytes from packet queue", packet->len);
+		mesh->self->in_packets++;
+		mesh->self->in_bytes += packet->len;
+		route(mesh, mesh->self, packet);
+		free(packet);
+	}
 }
 
 ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination) {
@@ -1960,7 +2175,9 @@ ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination)
 		return -1;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	node_t *n = (node_t *)destination;
 
@@ -1983,7 +2200,9 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return NULL;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	node_t *n = (node_t *)node;
 
@@ -2020,7 +2239,10 @@ meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
 
 	node_t *n = NULL;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	n = lookup_node(mesh, (char *)name); // TODO: make lookup_node() use const
 	pthread_mutex_unlock(&mesh->mutex);
 
@@ -2039,7 +2261,10 @@ meshlink_submesh_t *meshlink_get_submesh(meshlink_handle_t *mesh, const char *na
 
 	meshlink_submesh_t *submesh = NULL;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	submesh = (meshlink_submesh_t *)lookup_submesh(mesh, name);
 	pthread_mutex_unlock(&mesh->mutex);
 
@@ -2059,7 +2284,9 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 	meshlink_node_t **result;
 
 	//lock mesh->nodes
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	*nmemb = mesh->nodes->count;
 	result = realloc(nodes, *nmemb * sizeof(*nodes));
@@ -2084,7 +2311,9 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 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;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	*nmemb = 0;
 
@@ -2201,7 +2430,9 @@ dev_class_t meshlink_get_node_dev_class(meshlink_handle_t *mesh, meshlink_node_t
 
 	dev_class_t devclass;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	devclass = ((node_t *)node)->devclass;
 
@@ -2234,7 +2465,10 @@ bool meshlink_get_node_reachability(struct meshlink_handle *mesh, struct meshlin
 	node_t *n = (node_t *)node;
 	bool reachable;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	reachable = n->status.reachable && !n->status.blacklisted;
 
 	if(last_reachable) {
@@ -2261,7 +2495,9 @@ bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	if(!ecdsa_sign(mesh->private_key, data, len, signature)) {
 		meshlink_errno = MESHLINK_EINTERNAL;
@@ -2275,7 +2511,7 @@ bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *
 }
 
 bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const void *data, size_t len, const void *signature, size_t siglen) {
-	if(!mesh || !data || !len || !signature) {
+	if(!mesh || !source || !data || !len || !signature) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
@@ -2285,7 +2521,9 @@ bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const voi
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	bool rval = false;
 
@@ -2303,7 +2541,9 @@ bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const voi
 }
 
 static bool refresh_invitation_key(meshlink_handle_t *mesh) {
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	size_t count = invitation_purge_old(mesh, time(NULL) - mesh->invitation_timeout);
 
@@ -2323,13 +2563,20 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
 	}
 
 	if(!is_valid_hostname(address)) {
-		logger(mesh, MESHLINK_DEBUG, "Invalid character in address: %s\n", address);
+		logger(mesh, MESHLINK_DEBUG, "Invalid character in address: %s", address);
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
 
+	if((node_t *)node != mesh->self && !port) {
+		logger(mesh, MESHLINK_DEBUG, "Missing port number!");
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+
+	}
+
 	if(port && !is_valid_port(port)) {
-		logger(mesh, MESHLINK_DEBUG, "Invalid character in port: %s\n", address);
+		logger(mesh, MESHLINK_DEBUG, "Invalid character in port: %s", address);
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
@@ -2342,7 +2589,9 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
 		canonical_address = xstrdup(address);
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	node_t *n = (node_t *)node;
 	free(n->canonical_address);
@@ -2358,6 +2607,64 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
 	return config_sync(mesh, "current");
 }
 
+bool meshlink_add_invitation_address(struct meshlink_handle *mesh, const char *address, const char *port) {
+	if(!mesh || !address) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(!is_valid_hostname(address)) {
+		logger(mesh, MESHLINK_DEBUG, "Invalid character in address: %s\n", address);
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(port && !is_valid_port(port)) {
+		logger(mesh, MESHLINK_DEBUG, "Invalid character in port: %s\n", address);
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	char *combo;
+
+	if(port) {
+		xasprintf(&combo, "%s/%s", address, port);
+	} else {
+		combo = xstrdup(address);
+	}
+
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
+	if(!mesh->invitation_addresses) {
+		mesh->invitation_addresses = list_alloc((list_action_t)free);
+	}
+
+	list_insert_tail(mesh->invitation_addresses, combo);
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return true;
+}
+
+void meshlink_clear_invitation_addresses(struct meshlink_handle *mesh) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
+	if(mesh->invitation_addresses) {
+		list_delete_list(mesh->invitation_addresses);
+		mesh->invitation_addresses = NULL;
+	}
+
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
 bool meshlink_add_address(meshlink_handle_t *mesh, const char *address) {
 	return meshlink_set_canonical_address(mesh, (meshlink_node_t *)mesh->self, address, NULL);
 }
@@ -2374,7 +2681,7 @@ bool meshlink_add_external_address(meshlink_handle_t *mesh) {
 		return false;
 	}
 
-	bool rval = meshlink_add_address(mesh, address);
+	bool rval = meshlink_set_canonical_address(mesh, (meshlink_node_t *)mesh->self, address, NULL);
 	free(address);
 
 	return rval;
@@ -2393,7 +2700,10 @@ int meshlink_get_port(meshlink_handle_t *mesh) {
 
 	int port;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	port = atoi(mesh->myport);
 	pthread_mutex_unlock(&mesh->mutex);
 
@@ -2410,7 +2720,7 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 		return true;
 	}
 
-	if(!try_bind(port)) {
+	if(!try_bind(mesh, port)) {
 		meshlink_errno = MESHLINK_ENETWORK;
 		return false;
 	}
@@ -2419,7 +2729,9 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 
 	bool rval = false;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	if(mesh->threadstarted) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -2489,7 +2801,9 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 		s = (meshlink_submesh_t *)mesh->self->submesh;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	// Check validity of the new node's name
 	if(!check_id(name)) {
@@ -2631,7 +2945,9 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	//TODO: think of a better name for this variable, or of a different way to tokenize the invitation URL.
 	char copy[strlen(invitation) + 1];
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	//Before doing meshlink_join make sure we are not connected to another mesh
 	if(mesh->threadstarted) {
@@ -2719,11 +3035,11 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 		}
 
 		// Connect to the meshlink daemon mentioned in the URL.
-		struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
+		struct addrinfo *ai = adns_blocking_request(mesh, xstrdup(address), xstrdup(port), SOCK_STREAM, 5);
 
 		if(ai) {
 			for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
-				state.sock = socket_in_netns(aip->ai_family, aip->ai_socktype, aip->ai_protocol, mesh->netns);
+				state.sock = socket_in_netns(aip->ai_family, SOCK_STREAM, IPPROTO_TCP, mesh->netns);
 
 				if(state.sock == -1) {
 					logger(mesh, MESHLINK_DEBUG, "Could not open socket: %s\n", strerror(errno));
@@ -2731,6 +3047,11 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 					continue;
 				}
 
+#ifdef SO_NOSIGPIPE
+				int nosigpipe = 1;
+				setsockopt(state.sock, SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe, sizeof(nosigpipe));
+#endif
+
 				set_timeout(state.sock, 5000);
 
 				if(connect(state.sock, aip->ai_addr, aip->ai_addrlen)) {
@@ -2740,6 +3061,8 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 					state.sock = -1;
 					continue;
 				}
+
+				break;
 			}
 
 			freeaddrinfo(ai);
@@ -2880,12 +3203,22 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 	packmsg_add_str(&out, mesh->name);
 	packmsg_add_str(&out, CORE_MESH);
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	packmsg_add_int32(&out, mesh->self->devclass);
 	packmsg_add_bool(&out, mesh->self->status.blacklisted);
 	packmsg_add_bin(&out, ecdsa_get_public_key(mesh->private_key), 32);
-	packmsg_add_str(&out, mesh->self->canonical_address ? mesh->self->canonical_address : "");
+
+	if(mesh->self->canonical_address && !strchr(mesh->self->canonical_address, ' ')) {
+		char *canonical_address = NULL;
+		xasprintf(&canonical_address, "%s %s", mesh->self->canonical_address, mesh->myport);
+		packmsg_add_str(&out, canonical_address);
+		free(canonical_address);
+	} else {
+		packmsg_add_str(&out, mesh->self->canonical_address ? mesh->self->canonical_address : "");
+	}
 
 	uint32_t count = 0;
 
@@ -2960,17 +3293,19 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	while(count--) {
-		const void *data;
-		uint32_t len = packmsg_get_bin_raw(&in, &data);
+		const void *data2;
+		uint32_t len2 = packmsg_get_bin_raw(&in, &data2);
 
-		if(!len) {
+		if(!len2) {
 			break;
 		}
 
-		packmsg_input_t in2 = {data, len};
+		packmsg_input_t in2 = {data2, len2};
 		uint32_t version = packmsg_get_uint32(&in2);
 		char *name = packmsg_get_str_dup(&in2);
 
@@ -2996,7 +3331,7 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		n = new_node();
 		n->name = name;
 
-		config_t config = {data, len};
+		config_t config = {data2, len2};
 
 		if(!node_read_from_config(mesh, n, &config)) {
 			free_node(n);
@@ -3065,7 +3400,7 @@ static bool blacklist(meshlink_handle_t *mesh, node_t *n) {
 	n->status.udp_confirmed = false;
 
 	if(n->status.reachable) {
-		n->last_unreachable = mesh->loop.now.tv_sec;
+		n->last_unreachable = time(NULL);
 	}
 
 	/* Graph updates will suppress status updates for blacklisted nodes, so we need to
@@ -3084,7 +3419,9 @@ bool meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	if(!blacklist(mesh, (node_t *)node)) {
 		pthread_mutex_unlock(&mesh->mutex);
@@ -3103,7 +3440,9 @@ bool meshlink_blacklist_by_name(meshlink_handle_t *mesh, const char *name) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	node_t *n = lookup_node(mesh, (char *)name);
 
@@ -3139,7 +3478,7 @@ static bool whitelist(meshlink_handle_t *mesh, node_t *n) {
 	n->status.blacklisted = false;
 
 	if(n->status.reachable) {
-		n->last_reachable = mesh->loop.now.tv_sec;
+		n->last_reachable = time(NULL);
 		update_node_status(mesh, n);
 	}
 
@@ -3152,7 +3491,9 @@ bool meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	if(!whitelist(mesh, (node_t *)node)) {
 		pthread_mutex_unlock(&mesh->mutex);
@@ -3171,7 +3512,9 @@ bool meshlink_whitelist_by_name(meshlink_handle_t *mesh, const char *name) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	node_t *n = lookup_node(mesh, (char *)name);
 
@@ -3204,7 +3547,9 @@ bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
 
 	node_t *n = (node_t *)node;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	/* Check that the node is not reachable */
 	if(n->status.reachable || n->connection) {
@@ -3233,7 +3578,7 @@ bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	if(mesh->outgoings) {
 		for list_each(outgoing_t, outgoing, mesh->outgoings) {
 			if(outgoing->node == n) {
-				list_delete_node(mesh->outgoings, node);
+				list_delete_node(mesh->outgoings, list_node);
 			}
 		}
 	}
@@ -3261,7 +3606,9 @@ void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	node_t *n = (node_t *)node;
 
@@ -3282,16 +3629,46 @@ static bool channel_pre_accept(struct utcp *utcp, uint16_t port) {
 	return mesh->channel_accept_cb;
 }
 
-static void aio_signal(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_aio_buffer_t *aio) {
-	if(aio->data) {
-		if(aio->cb.buffer) {
-			aio->cb.buffer(mesh, channel, aio->data, aio->len, aio->priv);
+/* Finish one AIO buffer, return true if the channel is still open. */
+static bool aio_finish_one(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_aio_buffer_t **head) {
+	meshlink_aio_buffer_t *aio = *head;
+	*head = aio->next;
+
+	if(channel->c) {
+		channel->in_callback = true;
+
+		if(aio->data) {
+			if(aio->cb.buffer) {
+				aio->cb.buffer(mesh, channel, aio->data, aio->done, aio->priv);
+			}
+		} else {
+			if(aio->cb.fd) {
+				aio->cb.fd(mesh, channel, aio->fd, aio->done, aio->priv);
+			}
 		}
-	} else {
-		if(aio->cb.fd) {
-			aio->cb.fd(mesh, channel, aio->fd, aio->done, aio->priv);
+
+		channel->in_callback = false;
+
+		if(!channel->c) {
+			free(aio);
+			free(channel);
+			return false;
+		}
+	}
+
+	free(aio);
+	return true;
+}
+
+/* Finish all AIO buffers, return true if the channel is still open. */
+static bool aio_abort(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_aio_buffer_t **head) {
+	while(*head) {
+		if(!aio_finish_one(mesh, channel, head)) {
+			return false;
 		}
 	}
+
+	return true;
 }
 
 static ssize_t channel_recv(struct utcp_connection *connection, const void *data, size_t len) {
@@ -3313,6 +3690,15 @@ static ssize_t channel_recv(struct utcp_connection *connection, const void *data
 	size_t left = len;
 
 	while(channel->aio_receive) {
+		if(!len) {
+			/* This receive callback signalled an error, abort all outstanding AIO buffers. */
+			if(!aio_abort(mesh, channel, &channel->aio_receive)) {
+				return len;
+			}
+
+			break;
+		}
+
 		meshlink_aio_buffer_t *aio = channel->aio_receive;
 		size_t todo = aio->len - aio->done;
 
@@ -3325,23 +3711,35 @@ static ssize_t channel_recv(struct utcp_connection *connection, const void *data
 		} else {
 			ssize_t result = write(aio->fd, p, todo);
 
-			if(result > 0) {
-				todo = result;
+			if(result <= 0) {
+				if(result < 0 && errno == EINTR) {
+					continue;
+				}
+
+				/* Writing to fd failed, cancel just this AIO buffer. */
+				logger(mesh, MESHLINK_ERROR, "Writing to AIO fd %d failed: %s", aio->fd, strerror(errno));
+
+				if(!aio_finish_one(mesh, channel, &channel->aio_receive)) {
+					return len;
+				}
+
+				continue;
 			}
+
+			todo = result;
 		}
 
 		aio->done += todo;
+		p += todo;
+		left -= todo;
 
 		if(aio->done == aio->len) {
-			channel->aio_receive = aio->next;
-			aio_signal(mesh, channel, aio);
-			free(aio);
+			if(!aio_finish_one(mesh, channel, &channel->aio_receive)) {
+				return len;
+			}
 		}
 
-		p += todo;
-		left -= todo;
-
-		if(!left && len) {
+		if(!left) {
 			return len;
 		}
 	}
@@ -3377,6 +3775,17 @@ static void channel_accept(struct utcp_connection *utcp_connection, uint16_t por
 	}
 }
 
+static void channel_retransmit(struct utcp_connection *utcp_connection) {
+	node_t *n = utcp_connection->utcp->priv;
+	meshlink_handle_t *mesh = n->mesh;
+
+	if(n->mtuprobes == 31) {
+		timeout_set(&mesh->loop, &n->mtutimeout, &(struct timespec) {
+			0, 0
+		});
+	}
+}
+
 static ssize_t channel_send(struct utcp *utcp, const void *data, size_t len) {
 	node_t *n = utcp->priv;
 
@@ -3385,7 +3794,7 @@ static ssize_t channel_send(struct utcp *utcp, const void *data, size_t len) {
 	}
 
 	meshlink_handle_t *mesh = n->mesh;
-	return meshlink_send(mesh, (meshlink_node_t *)n, data, len) ? (ssize_t)len : -1;
+	return meshlink_send_immediate(mesh, (meshlink_node_t *)n, data, len) ? (ssize_t)len : -1;
 }
 
 void meshlink_set_channel_receive_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_receive_cb_t cb) {
@@ -3417,56 +3826,93 @@ static void channel_poll(struct utcp_connection *connection, size_t len) {
 
 	node_t *n = channel->node;
 	meshlink_handle_t *mesh = n->mesh;
-	meshlink_aio_buffer_t *aio = channel->aio_send;
 
-	if(aio) {
-		/* We at least one AIO buffer. Send as much as possible form the first buffer. */
-		size_t left = aio->len - aio->done;
+	while(channel->aio_send) {
+		if(!len) {
+			/* This poll callback signalled an error, abort all outstanding AIO buffers. */
+			if(!aio_abort(mesh, channel, &channel->aio_send)) {
+				return;
+			}
+
+			break;
+		}
+
+		/* We have at least one AIO buffer. Send as much as possible from the buffers. */
+		meshlink_aio_buffer_t *aio = channel->aio_send;
+		size_t todo = aio->len - aio->done;
 		ssize_t sent;
 
-		if(len > left) {
-			len = left;
+		if(todo > len) {
+			todo = len;
 		}
 
 		if(aio->data) {
-			sent = utcp_send(connection, (char *)aio->data + aio->done, len);
+			sent = utcp_send(connection, (char *)aio->data + aio->done, todo);
 		} else {
-			char buf[65536];
-			size_t todo = utcp_get_sndbuf_free(connection);
-
-			if(todo > left) {
-				todo = left;
-			}
-
-			if(todo > sizeof(buf)) {
-				todo = sizeof(buf);
+			/* Limit the amount we read at once to avoid stack overflows */
+			if(todo > 65536) {
+				todo = 65536;
 			}
 
+			char buf[todo];
 			ssize_t result = read(aio->fd, buf, todo);
 
 			if(result > 0) {
-				sent = utcp_send(connection, buf, result);
+				todo = result;
+				sent = utcp_send(connection, buf, todo);
 			} else {
-				sent = result;
+				if(result < 0 && errno == EINTR) {
+					continue;
+				}
+
+				/* Reading from fd failed, cancel just this AIO buffer. */
+				if(result != 0) {
+					logger(mesh, MESHLINK_ERROR, "Reading from AIO fd %d failed: %s", aio->fd, strerror(errno));
+				}
+
+				if(!aio_finish_one(mesh, channel, &channel->aio_send)) {
+					return;
+				}
+
+				continue;
 			}
 		}
 
-		if(sent >= 0) {
-			aio->done += sent;
+		if(sent != (ssize_t)todo) {
+			/* We should never get a partial send at this point */
+			assert(sent <= 0);
+
+			/* Sending failed, abort all outstanding AIO buffers and send a poll callback. */
+			if(!aio_abort(mesh, channel, &channel->aio_send)) {
+				return;
+			}
+
+			len = 0;
+			break;
 		}
 
-		/* If the buffer is now completely sent, call the callback and dispose of it. */
-		if(aio->done >= aio->len) {
-			channel->aio_send = aio->next;
-			aio_signal(mesh, channel, aio);
-			free(aio);
+		aio->done += sent;
+		len -= sent;
+
+		/* If we didn't finish this buffer, exit early. */
+		if(aio->done < aio->len) {
+			return;
 		}
-	} else {
-		if(channel->poll_cb) {
-			channel->poll_cb(mesh, channel, len);
-		} else {
-			utcp_set_poll_cb(connection, NULL);
+
+		/* Signal completion of this buffer, and go to the next one. */
+		if(!aio_finish_one(mesh, channel, &channel->aio_send)) {
+			return;
 		}
+
+		if(!len) {
+			return;
+		}
+	}
+
+	if(channel->poll_cb) {
+		channel->poll_cb(mesh, channel, len);
+	} else {
+		utcp_set_poll_cb(connection, NULL);
 	}
 }
 
@@ -3476,7 +3922,10 @@ void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	channel->poll_cb = cb;
 	utcp_set_poll_cb(channel->c, (cb || channel->aio_send) ? channel_poll : NULL);
 	pthread_mutex_unlock(&mesh->mutex);
@@ -3488,13 +3937,18 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	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);
 		}
 	}
 
@@ -3509,7 +3963,10 @@ void meshlink_set_channel_sndbuf(meshlink_handle_t *mesh, meshlink_channel_t *ch
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	utcp_set_sndbuf(channel->c, size);
 	pthread_mutex_unlock(&mesh->mutex);
 }
@@ -3522,7 +3979,10 @@ void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *ch
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	utcp_set_rcvbuf(channel->c, size);
 	pthread_mutex_unlock(&mesh->mutex);
 }
@@ -3537,12 +3997,16 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 		return NULL;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	node_t *n = (node_t *)node;
 
 	if(!n->utcp) {
 		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);
 		mesh->receive_cb = channel_receive;
 
 		if(!n->utcp) {
@@ -3590,7 +4054,10 @@ void meshlink_channel_shutdown(meshlink_handle_t *mesh, meshlink_channel_t *chan
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	utcp_shutdown(channel->c, direction);
 	pthread_mutex_unlock(&mesh->mutex);
 }
@@ -3601,26 +4068,24 @@ void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
-	utcp_close(channel->c);
+	if(channel->c) {
+		utcp_close(channel->c);
+		channel->c = NULL;
 
-	/* Clean up any outstanding AIO buffers. */
-	for(meshlink_aio_buffer_t *aio = channel->aio_send, *next; aio; aio = next) {
-		next = aio->next;
-		aio_signal(mesh, channel, aio);
-		free(aio);
+		/* Clean up any outstanding AIO buffers. */
+		aio_abort(mesh, channel, &channel->aio_send);
+		aio_abort(mesh, channel, &channel->aio_receive);
 	}
 
-	for(meshlink_aio_buffer_t *aio = channel->aio_receive, *next; aio; aio = next) {
-		next = aio->next;
-		aio_signal(mesh, channel, aio);
-		free(aio);
+	if(!channel->in_callback) {
+		free(channel);
 	}
 
 	pthread_mutex_unlock(&mesh->mutex);
-
-	free(channel);
 }
 
 ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len) {
@@ -3645,7 +4110,9 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 
 	ssize_t retval;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	/* Disallow direct calls to utcp_send() while we still have AIO active. */
 	if(channel->aio_send) {
@@ -3680,7 +4147,9 @@ bool meshlink_channel_aio_send(meshlink_handle_t *mesh, meshlink_channel_t *chan
 	aio->cb.buffer = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_send;
@@ -3693,7 +4162,11 @@ bool meshlink_channel_aio_send(meshlink_handle_t *mesh, meshlink_channel_t *chan
 
 	/* Ensure the poll callback is set, and call it right now to push data if possible */
 	utcp_set_poll_cb(channel->c, channel_poll);
-	channel_poll(channel->c, len);
+	size_t todo = MIN(len, utcp_get_rcvbuf_free(channel->c));
+
+	if(todo) {
+		channel_poll(channel->c, todo);
+	}
 
 	pthread_mutex_unlock(&mesh->mutex);
 
@@ -3717,7 +4190,9 @@ bool meshlink_channel_aio_fd_send(meshlink_handle_t *mesh, meshlink_channel_t *c
 	aio->cb.fd = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_send;
@@ -3730,7 +4205,11 @@ bool meshlink_channel_aio_fd_send(meshlink_handle_t *mesh, meshlink_channel_t *c
 
 	/* Ensure the poll callback is set, and call it right now to push data if possible */
 	utcp_set_poll_cb(channel->c, channel_poll);
-	channel_poll(channel->c, len);
+	size_t left = utcp_get_rcvbuf_free(channel->c);
+
+	if(left) {
+		channel_poll(channel->c, left);
+	}
 
 	pthread_mutex_unlock(&mesh->mutex);
 
@@ -3754,7 +4233,9 @@ bool meshlink_channel_aio_receive(meshlink_handle_t *mesh, meshlink_channel_t *c
 	aio->cb.buffer = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_receive;
@@ -3787,7 +4268,9 @@ bool meshlink_channel_aio_fd_receive(meshlink_handle_t *mesh, meshlink_channel_t
 	aio->cb.fd = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_receive;
@@ -3830,6 +4313,15 @@ size_t meshlink_channel_get_recvq(meshlink_handle_t *mesh, meshlink_channel_t *c
 	return utcp_get_recvq(channel->c);
 }
 
+size_t meshlink_channel_get_mss(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	return utcp_get_mss(channel->node->utcp);
+}
+
 void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t *node, int timeout) {
 	if(!mesh || !node) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -3838,10 +4330,14 @@ void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t
 
 	node_t *n = (node_t *)node;
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	if(!n->utcp) {
 		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);
 	}
 
 	utcp_set_user_timeout(n->utcp, timeout);
@@ -3852,6 +4348,8 @@ void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t
 void update_node_status(meshlink_handle_t *mesh, node_t *n) {
 	if(n->status.reachable && mesh->channel_accept_cb && !n->utcp) {
 		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->node_status_cb) {
@@ -3864,6 +4362,8 @@ void update_node_status(meshlink_handle_t *mesh, node_t *n) {
 }
 
 void update_node_pmtu(meshlink_handle_t *mesh, node_t *n) {
+	utcp_set_mtu(n->utcp, (n->minmtu > MINMTU ? n->minmtu : MINMTU) - sizeof(meshlink_packethdr_t));
+
 	if(mesh->node_pmtu_cb && !n->status.blacklisted) {
 		mesh->node_pmtu_cb(mesh, (meshlink_node_t *)n, n->minmtu);
 	}
@@ -3886,7 +4386,9 @@ void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
 
 	if(mesh->discovery == enable) {
 		goto end;
@@ -3922,7 +4424,10 @@ void meshlink_set_dev_class_timeouts(meshlink_handle_t *mesh, dev_class_t devcla
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->dev_class_traits[devclass].pinginterval = pinginterval;
 	mesh->dev_class_traits[devclass].pingtimeout = pingtimeout;
 	pthread_mutex_unlock(&mesh->mutex);
@@ -3939,22 +4444,89 @@ void meshlink_set_dev_class_fast_retry_period(meshlink_handle_t *mesh, dev_class
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->dev_class_traits[devclass].fast_retry_period = fast_retry_period;
 	pthread_mutex_unlock(&mesh->mutex);
 }
 
-extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, bool inviter_commits_first) {
+void meshlink_set_dev_class_maxtimeout(struct meshlink_handle *mesh, dev_class_t devclass, int maxtimeout) {
+	if(!mesh || devclass < 0 || devclass >= DEV_CLASS_COUNT) {
+		meshlink_errno = EINVAL;
+		return;
+	}
+
+	if(maxtimeout < 0) {
+		meshlink_errno = EINVAL;
+		return;
+	}
+
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
+	mesh->dev_class_traits[devclass].maxtimeout = maxtimeout;
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_reset_timers(struct meshlink_handle *mesh) {
+	if(!mesh) {
+		return;
+	}
+
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
+	handle_network_change(mesh, true);
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, bool inviter_commits_first) {
 	if(!mesh) {
 		meshlink_errno = EINVAL;
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
 	mesh->inviter_commits_first = inviter_commits_first;
 	pthread_mutex_unlock(&mesh->mutex);
 }
 
+void meshlink_set_external_address_discovery_url(struct meshlink_handle *mesh, const char *url) {
+	if(!mesh) {
+		meshlink_errno = EINVAL;
+		return;
+	}
+
+	if(url && (strncmp(url, "http://", 7) || strchr(url, ' '))) {
+		meshlink_errno = EINVAL;
+		return;
+	}
+
+	if(pthread_mutex_lock(&mesh->mutex) != 0) {
+		abort();
+	}
+
+	free(mesh->external_address_url);
+	mesh->external_address_url = url ? xstrdup(url) : NULL;
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_scheduling_granularity(struct meshlink_handle *mesh, long granularity) {
+	if(!mesh || granularity < 0) {
+		meshlink_errno = EINVAL;
+		return;
+	}
+
+	utcp_set_clock_granularity(granularity);
+}
+
 void handle_network_change(meshlink_handle_t *mesh, bool online) {
 	(void)online;
 
@@ -3963,9 +4535,10 @@ void handle_network_change(meshlink_handle_t *mesh, bool online) {
 	}
 
 	retry(mesh);
+	signal_trigger(&mesh->loop, &mesh->datafromapp);
 }
 
-void call_error_cb(meshlink_handle_t *mesh, meshlink_errno_t meshlink_errno) {
+void call_error_cb(meshlink_handle_t *mesh, meshlink_errno_t cb_errno) {
 	// We should only call the callback function if we are in the background thread.
 	if(!mesh->error_cb) {
 		return;
@@ -3976,12 +4549,13 @@ void call_error_cb(meshlink_handle_t *mesh, meshlink_errno_t meshlink_errno) {
 	}
 
 	if(mesh->thread == pthread_self()) {
-		mesh->error_cb(mesh, meshlink_errno);
+		mesh->error_cb(mesh, cb_errno);
 	}
 }
 
 static void __attribute__((constructor)) meshlink_init(void) {
 	crypto_init();
+	utcp_set_clock_granularity(10000);
 }
 
 static void __attribute__((destructor)) meshlink_exit(void) {