X-Git-Url: http://git.meshlink.io/?p=meshlink;a=blobdiff_plain;f=src%2Fmeshlink.c;h=3242bc267d625a34686e06804cb4efa925fcd652;hp=def3e6efc9557a7d83d7b4d587b223eb1e256ba1;hb=963c5055505f2fc117cd5efa06eaa02c9b2bf85d;hpb=d8c4f59c17daf8d2728ad2ecb4583822376d44ec

diff --git a/src/meshlink.c b/src/meshlink.c
index def3e6ef..3242bc26 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -24,6 +24,7 @@
 #include "ecdsagen.h"
 #include "logger.h"
 #include "meshlink_internal.h"
+#include "net.h"
 #include "netutl.h"
 #include "node.h"
 #include "submesh.h"
@@ -221,12 +222,42 @@ 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 = str2addrinfo(host, port ? port : "80", SOCK_STREAM);
 	char line[256];
+	char *hostname = NULL;
 
 	for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 		if(family != AF_UNSPEC && aip->ai_family != family) {
@@ -245,7 +276,9 @@ 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) {
@@ -389,10 +422,15 @@ 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;
 	}
@@ -401,44 +439,61 @@ 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;
 		}
@@ -456,8 +511,10 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
 			continue;
 		}
 
-		// Remember the address
-		node_add_recent_address(mesh, mesh->self, (sockaddr_t *)ai_in->ai_addr);
+		// 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);
+		}
 
 		if(flags & MESHLINK_INVITE_NUMERIC) {
 			// We don't need to do any further conversion
@@ -500,10 +557,10 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
 	}
 
 	// 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 +578,7 @@ 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,
@@ -542,16 +599,9 @@ static bool try_bind(int port) {
 	for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 		/* Try to bind to TCP. */
 
-		int tcp_fd = socket(aip->ai_family, SOCK_STREAM, IPPROTO_TCP);
+		int tcp_fd = setup_tcp_listen_socket(mesh, aip);
 
 		if(tcp_fd == -1) {
-			continue;
-		}
-
-		int result = bind(tcp_fd, aip->ai_addr, aip->ai_addrlen);
-		closesocket(tcp_fd);
-
-		if(result) {
 			if(errno == EADDRINUSE) {
 				/* If this port is in use for any address family, avoid it. */
 				success = false;
@@ -563,21 +613,16 @@ static bool try_bind(int port) {
 
 		/* If TCP worked, then we require that UDP works as well. */
 
-		int udp_fd = socket(aip->ai_family, SOCK_DGRAM, IPPROTO_UDP);
+		int udp_fd = setup_udp_listen_socket(mesh, aip);
 
 		if(udp_fd == -1) {
+			closesocket(tcp_fd);
 			success = false;
 			break;
 		}
 
-		result = bind(udp_fd, aip->ai_addr, aip->ai_addrlen);
+		closesocket(tcp_fd);
 		closesocket(udp_fd);
-
-		if(result) {
-			success = false;
-			break;
-		}
-
 		success = true;
 	}
 
@@ -585,11 +630,11 @@ static bool try_bind(int port) {
 	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;
@@ -951,10 +996,18 @@ 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) {
@@ -963,7 +1016,7 @@ 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;
 		}
 	}
@@ -1117,7 +1170,6 @@ 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
@@ -1405,6 +1457,7 @@ 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));
 
@@ -1490,7 +1543,6 @@ 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) {
@@ -1754,8 +1806,14 @@ 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);
@@ -1907,20 +1965,10 @@ void meshlink_set_error_cb(struct meshlink_handle *mesh, meshlink_error_cb_t 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;
 	}
@@ -1934,13 +1982,6 @@ 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);
@@ -1954,6 +1995,54 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 
 	memcpy(packet->data + sizeof(*hdr), data, len);
 
+	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;
+	}
+
+	// Send it immediately
+	route(mesh, mesh->self, mesh->packet);
+
+	return true;
+}
+
+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) {
+		meshlink_errno = MESHLINK_ENOMEM;
+		return false;
+	}
+
+	if(!prepare_packet(mesh, destination, data, len, packet)) {
+		free(packet);
+	}
+
 	// Queue it
 	if(!meshlink_queue_push(&mesh->outpacketqueue, packet)) {
 		free(packet);
@@ -1961,6 +2050,8 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 		return false;
 	}
 
+	logger(mesh, MESHLINK_DEBUG, "Adding packet of %zu bytes to packet queue", len);
+
 	// Notify event loop
 	signal_trigger(&mesh->loop, &mesh->datafromapp);
 
@@ -1970,17 +2061,16 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 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);
-
-	if(!packet) {
-		return;
-	}
 
-	mesh->self->in_packets++;
-	mesh->self->in_bytes += packet->len;
-	route(mesh, mesh->self, packet);
+	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) {
@@ -2387,6 +2477,60 @@ 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);
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	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;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	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);
 }
@@ -2403,7 +2547,7 @@ 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;
@@ -2439,7 +2583,7 @@ 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;
 	}
@@ -3096,7 +3240,7 @@ 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
@@ -3170,7 +3314,7 @@ 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);
 	}
 
@@ -3416,7 +3560,7 @@ 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) {
@@ -3526,6 +3670,7 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 	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));
 		}
 	}
 
@@ -3574,6 +3719,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 
 	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));
 		mesh->receive_cb = channel_receive;
 
 		if(!n->utcp) {
@@ -3861,6 +4007,15 @@ 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;
@@ -3873,6 +4028,7 @@ void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t
 
 	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_user_timeout(n->utcp, timeout);
@@ -3883,6 +4039,7 @@ 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));
 	}
 
 	if(mesh->node_status_cb) {
@@ -3895,6 +4052,8 @@ 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);
 	}
@@ -3986,6 +4145,23 @@ extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, boo
 	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;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+	free(mesh->external_address_url);
+	mesh->external_address_url = url ? xstrdup(url) : NULL;
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
 void handle_network_change(meshlink_handle_t *mesh, bool online) {
 	(void)online;