X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fmeshlink.c;h=6a2c99da68d8c416f79704a3dd8b615ba8906921;hb=5dec7459d9920c930bdfb3ac0f2a3740a6247ec0;hp=8266633269845631160fbf9ee5641d46e1f7bd5f;hpb=ea17ede077e84f88c7f20e9053b38086583ab635;p=meshlink

diff --git a/src/meshlink.c b/src/meshlink.c
index 82666332..6a2c99da 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -1,6 +1,6 @@
 /*
     meshlink.c -- Implementation of the MeshLink API.
-    Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
+    Copyright (C) 2014, 2017 Guus Sliepen <guus@meshlink.io>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -39,6 +39,7 @@ typedef struct {
 #include "node.h"
 #include "protocol.h"
 #include "route.h"
+#include "sockaddr.h"
 #include "utils.h"
 #include "xalloc.h"
 #include "ed25519/sha512.h"
@@ -164,9 +165,9 @@ static void scan_for_hostname(const char *filename, char **hostname, char **port
 		p += strspn(p, "\t ");
 		p[strcspn(p, "\t ")] = 0;
 
-		if(!*port && !strcasecmp(line, "Port")) {
+		if(!*port && !strcasecmp(line, "Port"))
 			*port = xstrdup(q);
-		} else if(!*hostname && !strcasecmp(line, "Address")) {
+		else if(!*hostname && !strcasecmp(line, "Address")) {
 			*hostname = xstrdup(q);
 			if(*p) {
 				free(*port);
@@ -180,31 +181,41 @@ static void scan_for_hostname(const char *filename, char **hostname, char **port
 
 	fclose(f);
 }
-static char *get_my_hostname(meshlink_handle_t* mesh) {
-	char *hostname = NULL;
-	char *port = NULL;
-	char *hostport = NULL;
-	char *name = mesh->self->name;
-	char filename[PATH_MAX] = "";
-	char line[4096];
-	FILE *f;
 
-	// Use first Address statement in own host config file
-	snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
-	scan_for_hostname(filename, &hostname, &port);
+static bool is_valid_hostname(const char *hostname) {
+	for(const char *p = hostname; *p; p++) {
+		if(!(isalnum(*p) || *p == '-' || *p == '.' || *p == ':'))
+			return false;
+	}
 
-	if(hostname)
-		goto done;
+	return true;
+}
+
+static void set_timeout(int sock, int timeout) {
+#ifdef _WIN32
+	DWORD tv = timeout;
+#else
+	struct timeval tv;
+	tv.tv_sec = timeout / 1000;
+	tv.tv_usec = (timeout - tv.tv_sec * 1000) * 1000;
+#endif
+	setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof tv);
+	setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
+}
+
+char *meshlink_get_external_address(meshlink_handle_t *mesh) {
+	char *hostname = NULL;
 
-	// If that doesn't work, guess externally visible hostname
 	logger(mesh, MESHLINK_DEBUG, "Trying to discover externally visible hostname...\n");
 	struct addrinfo *ai = str2addrinfo("meshlink.io", "80", SOCK_STREAM);
 	struct addrinfo *aip = ai;
 	static const char request[] = "GET http://www.meshlink.io/host.cgi HTTP/1.0\r\n\r\n";
+	char line[256];
 
 	while(aip) {
 		int s = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol);
 		if(s >= 0) {
+			set_timeout(s, 5000);
 			if(connect(s, aip->ai_addr, aip->ai_addrlen)) {
 				closesocket(s);
 				s = -1;
@@ -233,17 +244,33 @@ static char *get_my_hostname(meshlink_handle_t* mesh) {
 		freeaddrinfo(ai);
 
 	// Check that the hostname is reasonable
-	if(hostname) {
-		for(char *p = hostname; *p; p++) {
-			if(isalnum(*p) || *p == '-' || *p == '.' || *p == ':')
-				continue;
-			// If not, forget it.
-			free(hostname);
-			hostname = NULL;
-			break;
-		}
+	if(hostname && !is_valid_hostname(hostname)) {
+		free(hostname);
+		hostname = NULL;
 	}
 
+	if(!hostname)
+		meshlink_errno = MESHLINK_ERESOLV;
+
+	return hostname;
+}
+
+static char *get_my_hostname(meshlink_handle_t* mesh) {
+	char *hostname = NULL;
+	char *port = NULL;
+	char *hostport = NULL;
+	char *name = mesh->self->name;
+	char filename[PATH_MAX] = "";
+	FILE *f;
+
+	// Use first Address statement in own host config file
+	snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
+	scan_for_hostname(filename, &hostname, &port);
+
+	if(hostname)
+		goto done;
+
+	hostname = meshlink_get_external_address(mesh);
 	if(!hostname)
 		return NULL;
 
@@ -251,9 +278,8 @@ static char *get_my_hostname(meshlink_handle_t* mesh) {
 	if(f) {
 		fprintf(f, "\nAddress = %s\n", hostname);
 		fclose(f);
-	} else {
+	} else
 		logger(mesh, MESHLINK_DEBUG, "Could not append Address to %s: %s\n", filename, strerror(errno));
-	}
 
 done:
 	if(port) {
@@ -504,7 +530,7 @@ static bool finalize_join(meshlink_handle_t *mesh) {
 	if(!b64key) {
 		fclose(fh);
 		return false;
-		}
+	}
 
 	fprintf(fh, "ECDSAPublicKey = %s\n", b64key);
 	fprintf(fh, "Port = %s\n", mesh->myport);
@@ -543,28 +569,28 @@ static bool invitation_send(void *handle, uint8_t type, const void *data, size_t
 static bool invitation_receive(void *handle, uint8_t type, const void *msg, uint16_t len) {
 	meshlink_handle_t* mesh = handle;
 	switch(type) {
-		case SPTPS_HANDSHAKE:
-			return sptps_send_record(&(mesh->sptps), 0, mesh->cookie, sizeof mesh->cookie);
-
-		case 0:
-			mesh->data = xrealloc(mesh->data, mesh->thedatalen + len + 1);
-			memcpy(mesh->data + mesh->thedatalen, msg, len);
-			mesh->thedatalen += len;
-			mesh->data[mesh->thedatalen] = 0;
-			break;
-
-		case 1:
-			mesh->thedatalen = 0;
-			return finalize_join(mesh);
-
-		case 2:
-			logger(mesh, MESHLINK_DEBUG, "Invitation succesfully accepted.\n");
-			shutdown(mesh->sock, SHUT_RDWR);
-			mesh->success = true;
-			break;
-
-		default:
-			return false;
+	case SPTPS_HANDSHAKE:
+		return sptps_send_record(&(mesh->sptps), 0, mesh->cookie, sizeof mesh->cookie);
+
+	case 0:
+		mesh->data = xrealloc(mesh->data, mesh->thedatalen + len + 1);
+		memcpy(mesh->data + mesh->thedatalen, msg, len);
+		mesh->thedatalen += len;
+		mesh->data[mesh->thedatalen] = 0;
+		break;
+
+	case 1:
+		mesh->thedatalen = 0;
+		return finalize_join(mesh);
+
+	case 2:
+		logger(mesh, MESHLINK_DEBUG, "Invitation succesfully accepted.\n");
+		shutdown(mesh->sock, SHUT_RDWR);
+		mesh->success = true;
+		break;
+
+	default:
+		return false;
 	}
 
 	return true;
@@ -660,7 +686,7 @@ static bool ecdsa_keygen(meshlink_handle_t *mesh) {
 		logger(mesh, MESHLINK_DEBUG, "Done.\n");
 
 	snprintf(privname, sizeof privname, "%s" SLASH "ecdsa_key.priv", mesh->confbase);
-	f = fopen(privname, "w");
+	f = fopen(privname, "wb");
 
 	if(!f) {
 		meshlink_errno = MESHLINK_ESTORAGE;
@@ -701,16 +727,74 @@ static bool ecdsa_keygen(meshlink_handle_t *mesh) {
 
 static struct timeval idle(event_loop_t *loop, void *data) {
 	meshlink_handle_t *mesh = data;
-	int t, tmin = -1;
+	struct timeval t, tmin = {3600, 0};
 	for splay_each(node_t, n, mesh->nodes) {
 		if(!n->utcp)
 			continue;
 		t = utcp_timeout(n->utcp);
-		if(t >= 0 && t < tmin)
+		if(timercmp(&t, &tmin, <))
 			tmin = t;
 	}
-	struct timeval tv = {.tv_sec = t};
-	return tv;
+	return tmin;
+}
+
+// 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 getlocaladdrname(char *destaddr, char *host, socklen_t hostlen) {
+	struct addrinfo *rai = NULL;
+	const struct addrinfo hint = {
+		.ai_family = AF_UNSPEC,
+		.ai_socktype = SOCK_DGRAM,
+		.ai_protocol = IPPROTO_UDP,
+	};
+
+	if(getaddrinfo(destaddr, "80", &hint, &rai) || !rai)
+		return false;
+
+	int sock = socket(rai->ai_family, rai->ai_socktype, rai->ai_protocol);
+	if(sock == -1) {
+		freeaddrinfo(rai);
+		return false;
+	}
+
+	if(connect(sock, rai->ai_addr, rai->ai_addrlen) && !sockwouldblock(errno)) {
+		freeaddrinfo(rai);
+		return false;
+	}
+
+	freeaddrinfo(rai);
+
+	struct sockaddr_storage sn;
+	socklen_t sl = sizeof sn;
+
+	if(getsockname(sock, (struct sockaddr *)&sn, &sl))
+		return false;
+
+	if(getnameinfo((struct sockaddr *)&sn, sl, host, hostlen, NULL, 0, NI_NUMERICHOST | NI_NUMERICSERV))
+		return false;
+
+	return true;
+}
+
+// Get our local address(es) by simulating connecting to an Internet host.
+static void add_local_addresses(meshlink_handle_t *mesh) {
+	char host[NI_MAXHOST];
+	char entry[MAX_STRING_SIZE];
+
+	// IPv4 example.org
+
+	if(getlocaladdrname("93.184.216.34", host, sizeof host)) {
+		snprintf(entry, sizeof entry, "%s %s", host, mesh->myport);
+		append_config_file(mesh, mesh->name, "Address", entry);
+	}
+
+	// IPv6 example.org
+
+	if(getlocaladdrname("2606:2800:220:1:248:1893:25c8:1946", host, sizeof host)) {
+		snprintf(entry, sizeof entry, "%s %s", host, mesh->myport);
+		append_config_file(mesh, mesh->name, "Address", entry);
+	}
 }
 
 static bool meshlink_setup(meshlink_handle_t *mesh) {
@@ -758,14 +842,9 @@ static bool meshlink_setup(meshlink_handle_t *mesh) {
 }
 
 meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const char* appname, dev_class_t devclass) {
-	return meshlink_open_with_size(confbase, name, appname, devclass, sizeof(meshlink_handle_t));
-}
-
-meshlink_handle_t *meshlink_open_with_size(const char *confbase, const char *name, const char* appname, dev_class_t devclass, size_t size) {
-
 	// Validate arguments provided by the application
 	bool usingname = false;
-	
+
 	logger(NULL, MESHLINK_DEBUG, "meshlink_open called\n");
 
 	if(!confbase || !*confbase) {
@@ -783,14 +862,14 @@ meshlink_handle_t *meshlink_open_with_size(const char *confbase, const char *nam
 	if(!name || !*name) {
 		logger(NULL, MESHLINK_ERROR, "No name given!\n");
 		//return NULL;
-	}
-	else { //check name only if there is a name != NULL
+	} else { //check name only if there is a name != NULL
 
 		if(!check_id(name)) {
 			logger(NULL, MESHLINK_ERROR, "Invalid name given!\n");
 			meshlink_errno = MESHLINK_EINVAL;
 			return NULL;
-		} else { usingname = true;}
+		} else
+			usingname = true;
 	}
 
 	if(devclass < 0 || devclass > _DEV_CLASS_MAX) {
@@ -799,18 +878,18 @@ meshlink_handle_t *meshlink_open_with_size(const char *confbase, const char *nam
 		return NULL;
 	}
 
-	meshlink_handle_t *mesh = xzalloc(size);
+	meshlink_handle_t *mesh = xzalloc(sizeof(meshlink_handle_t));
 	mesh->confbase = xstrdup(confbase);
 	mesh->appname = xstrdup(appname);
 	mesh->devclass = devclass;
-	if (usingname) mesh->name = xstrdup(name);
+	if(usingname) mesh->name = xstrdup(name);
 
 	// initialize mutex
 	pthread_mutexattr_t attr;
 	pthread_mutexattr_init(&attr);
 	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
 	pthread_mutex_init(&(mesh->mesh_mutex), &attr);
-	
+
 	mesh->threadstarted = false;
 	event_loop_init(&mesh->loop);
 	mesh->loop.data = mesh;
@@ -859,6 +938,8 @@ meshlink_handle_t *meshlink_open_with_size(const char *confbase, const char *nam
 		return NULL;
 	}
 
+	add_local_addresses(mesh);
+
 	idle_set(&mesh->loop, idle, mesh);
 
 	logger(NULL, MESHLINK_DEBUG, "meshlink_open returning\n");
@@ -885,16 +966,29 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
-	pthread_mutex_lock(&(mesh->mesh_mutex));
-	
+
 	logger(mesh, MESHLINK_DEBUG, "meshlink_start called\n");
 
+	pthread_mutex_lock(&(mesh->mesh_mutex));
+
+	if(mesh->threadstarted) {
+		logger(mesh, MESHLINK_DEBUG, "thread was already running\n");
+		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		return true;
+	}
+
+	if(mesh->listen_socket[0].tcp.fd < 0) {
+		logger(mesh, MESHLINK_ERROR, "Listening socket not open\n");
+		meshlink_errno = MESHLINK_ENETWORK;
+		return false;
+	}
+
 	mesh->thedatalen = 0;
 
 	// TODO: open listening sockets first
 
 	//Check that a valid name is set
-	if(!mesh->name ) {
+	if(!mesh->name) {
 		logger(mesh, MESHLINK_DEBUG, "No name given!\n");
 		meshlink_errno = MESHLINK_EINVAL;
 		pthread_mutex_unlock(&(mesh->mesh_mutex));
@@ -903,6 +997,8 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	// Start the main thread
 
+	event_loop_start(&mesh->loop);
+
 	if(pthread_create(&mesh->thread, NULL, meshlink_main_loop, mesh) != 0) {
 		logger(mesh, MESHLINK_DEBUG, "Could not start thread: %s\n", strerror(errno));
 		memset(&mesh->thread, 0, sizeof mesh->thread);
@@ -913,7 +1009,8 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	mesh->threadstarted=true;
 
-	discovery_start(mesh);
+	if(mesh->discovery)
+		discovery_start(mesh);
 
 	pthread_mutex_unlock(&(mesh->mesh_mutex));
 	return true;
@@ -929,12 +1026,16 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 	logger(mesh, MESHLINK_DEBUG, "meshlink_stop called\n");
 
 	// Stop discovery
-	discovery_stop(mesh);
+	if(mesh->discovery)
+		discovery_stop(mesh);
 
-	// Shut down a listening socket to signal the main thread to shut down
+	// Shut down the main thread
+	event_loop_stop(&mesh->loop);
 
+	// Send ourselves a UDP packet to kick the event loop
 	listen_socket_t *s = &mesh->listen_socket[0];
-	shutdown(s->tcp.fd, SHUT_RDWR);
+	if(sendto(s->udp.fd, "", 1, MSG_NOSIGNAL, &s->sa.sa, SALEN(s->sa.sa)) == -1)
+		logger(mesh, MESHLINK_ERROR, "Could not send a UDP packet to ourself");
 
 	// Wait for the main thread to finish
 	pthread_mutex_unlock(&(mesh->mesh_mutex));
@@ -943,16 +1044,6 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 
 	mesh->threadstarted = false;
 
-	// Fix the socket
-	
-	closesocket(s->tcp.fd);
-	io_del(&mesh->loop, &s->tcp);
-	s->tcp.fd = setup_listen_socket(&s->sa);
-	if(s->tcp.fd < 0)
-		logger(mesh, MESHLINK_ERROR, "Could not repair listenen socket!");
-	else
-		io_add(&mesh->loop, &s->tcp, handle_new_meta_connection, s, s->tcp.fd, IO_READ);
-	
 	pthread_mutex_unlock(&(mesh->mesh_mutex));
 }
 
@@ -962,6 +1053,9 @@ void meshlink_close(meshlink_handle_t *mesh) {
 		return;
 	}
 
+	// stop can be called even if mesh has not been started
+	meshlink_stop(mesh);
+
 	// lock is not released after this
 	pthread_mutex_lock(&(mesh->mesh_mutex));
 
@@ -991,6 +1085,49 @@ void meshlink_close(meshlink_handle_t *mesh) {
 	free(mesh);
 }
 
+static void deltree(const char *dirname) {
+	DIR *d = opendir(dirname);
+	if(d) {
+		struct dirent *ent;
+		while((ent = readdir(d))) {
+			if(ent->d_name[0] == '.')
+				continue;
+			char filename[PATH_MAX];
+			snprintf(filename, sizeof filename, "%s" SLASH "%s", dirname, ent->d_name);
+			if(unlink(filename))
+				deltree(filename);
+		}
+		closedir(d);
+	}
+	rmdir(dirname);
+	return;
+}
+
+bool meshlink_destroy(const char *confbase) {
+	if(!confbase) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	char filename[PATH_MAX];
+	snprintf(filename, sizeof filename, "%s" SLASH "meshlink.conf", confbase);
+
+	if(unlink(filename)) {
+		if(errno == ENOENT) {
+			meshlink_errno = MESHLINK_ENOENT;
+			return false;
+		} else {
+			logger(NULL, MESHLINK_ERROR, "Cannot delete %s: %s\n", filename, strerror(errno));
+			meshlink_errno = MESHLINK_ESTORAGE;
+			return false;
+		}
+	}
+
+	deltree(confbase);
+
+	return true;
+}
+
 void meshlink_set_receive_cb(meshlink_handle_t *mesh, meshlink_receive_cb_t cb) {
 	if(!mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -1055,8 +1192,10 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 
 	hdr = (meshlink_packethdr_t *)packet->data;
 	memset(hdr, 0, sizeof *hdr);
-	memcpy(hdr->destination, destination->name, sizeof hdr->destination);
-	memcpy(hdr->source, mesh->self->name, sizeof hdr->source);
+	// leave the last byte as 0 to make sure strings are always
+	// null-terminated if they are longer than the buffer
+	strncpy(hdr->destination, destination->name, (sizeof hdr->destination) - 1);
+	strncpy(hdr->source, mesh->self->name, (sizeof hdr->source) -1);
 
 	memcpy(packet->data + sizeof *hdr, data, len);
 
@@ -1069,7 +1208,7 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 
 	// Notify event loop
 	signal_trigger(&(mesh->loop),&(mesh->datafromapp));
-	
+
 	return true;
 }
 
@@ -1094,13 +1233,11 @@ ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination)
 	if(!n->status.reachable) {
 		pthread_mutex_unlock(&(mesh->mesh_mutex));
 		return 0;
-	
-	}
-	else if(n->mtuprobes > 30 && n->minmtu) {
+
+	} else if(n->mtuprobes > 30 && n->minmtu) {
 		pthread_mutex_unlock(&(mesh->mesh_mutex));
 		return n->minmtu;
-	}
-	else {
+	} else {
 		pthread_mutex_unlock(&(mesh->mesh_mutex));
 		return MTU;
 	}
@@ -1130,6 +1267,15 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	return fingerprint;
 }
 
+meshlink_node_t *meshlink_get_self(meshlink_handle_t *mesh) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	return (meshlink_node_t *)mesh->self;
+}
+
 meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
 	if(!mesh || !name) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -1217,16 +1363,15 @@ bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const voi
 	if(!n->ecdsa) {
 		meshlink_errno = MESHLINK_EINTERNAL;
 		rval = false;
-	} else {
+	} else
 		rval = ecdsa_verify(((struct node_t *)source)->ecdsa, data, len, signature);
-	}
 	pthread_mutex_unlock(&(mesh->mesh_mutex));
 	return rval;
 }
 
 static bool refresh_invitation_key(meshlink_handle_t *mesh) {
 	char filename[PATH_MAX];
-	
+
 	pthread_mutex_lock(&(mesh->mesh_mutex));
 
 	snprintf(filename, sizeof filename, "%s" SLASH "invitations", mesh->confbase);
@@ -1295,7 +1440,7 @@ static bool refresh_invitation_key(meshlink_handle_t *mesh) {
 	}
 
 	// Create a new key if necessary.
-	FILE *f = fopen(filename, "r");
+	FILE *f = fopen(filename, "rb");
 	if(!f) {
 		if(errno != ENOENT) {
 			logger(mesh, MESHLINK_DEBUG, "Could not read %s: %s\n", filename, strerror(errno));
@@ -1311,7 +1456,7 @@ static bool refresh_invitation_key(meshlink_handle_t *mesh) {
 			pthread_mutex_unlock(&(mesh->mesh_mutex));
 			return false;
 		}
-		f = fopen(filename, "w");
+		f = fopen(filename, "wb");
 		if(!f) {
 			logger(mesh, MESHLINK_DEBUG, "Could not write %s: %s\n", filename, strerror(errno));
 			meshlink_errno = MESHLINK_ESTORAGE;
@@ -1339,22 +1484,99 @@ bool meshlink_add_address(meshlink_handle_t *mesh, const char *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;
+	}
+
 	bool rval = false;
 
 	pthread_mutex_lock(&(mesh->mesh_mutex));
+	rval = append_config_file(mesh, mesh->self->name, "Address", address);
+	pthread_mutex_unlock(&(mesh->mesh_mutex));
 
-	for(const char *p = address; *p; p++) {
-		if(isalnum(*p) || *p == '-' || *p == '.' || *p == ':')
-			continue;
-		logger(mesh, MESHLINK_DEBUG, "Invalid character in address: %s\n", address);
+	return rval;
+}
+
+bool meshlink_add_external_address(meshlink_handle_t *mesh) {
+	if(!mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
 		return false;
 	}
 
+	char *address = meshlink_get_external_address(mesh);
+	if(!address)
+		return false;
+
+	bool rval = false;
+
+	pthread_mutex_lock(&(mesh->mesh_mutex));
 	rval = append_config_file(mesh, mesh->self->name, "Address", address);
 	pthread_mutex_unlock(&(mesh->mesh_mutex));
+
+	free(address);
+	return rval;
+}
+
+int meshlink_get_port(meshlink_handle_t *mesh) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	if(!mesh->myport) {
+		meshlink_errno = MESHLINK_EINTERNAL;
+		return -1;
+	}
+
+	return atoi(mesh->myport);
+}
+
+bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
+	if(!mesh || port < 0 || port >= 65536 || mesh->threadstarted) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(mesh->myport && port == atoi(mesh->myport))
+		return true;
+
+	if(!try_bind(port)) {
+		meshlink_errno = MESHLINK_ENETWORK;
+		return false;
+	}
+
+	bool rval = false;
+
+	pthread_mutex_lock(&(mesh->mesh_mutex));
+	if(mesh->threadstarted) {
+		meshlink_errno = MESHLINK_EINVAL;
+		goto done;
+	}
+
+	close_network_connections(mesh);
+	exit_configuration(&mesh->config);
+
+	char portstr[10];
+	snprintf(portstr, sizeof portstr, "%d", port);
+	portstr[sizeof portstr - 1] = 0;
+
+	modify_config_file(mesh, mesh->name, "Port", portstr, true);
+
+	init_configuration(&mesh->config);
+
+	if(!read_server_config(mesh))
+		meshlink_errno = MESHLINK_ESTORAGE;
+	else if(!setup_network(mesh))
+		meshlink_errno = MESHLINK_ENETWORK;
+	else
+		rval = true;
+
+done:
+	pthread_mutex_unlock(&(mesh->mesh_mutex));
+
 	return rval;
 }
 
@@ -1363,7 +1585,7 @@ char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return NULL;
 	}
-	
+
 	pthread_mutex_lock(&(mesh->mesh_mutex));
 
 	// Check validity of the new node's name
@@ -1446,7 +1668,7 @@ char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
 	// Fill in the details.
 	fprintf(f, "Name = %s\n", name);
 	//if(netname)
-	//	fprintf(f, "NetName = %s\n", netname);
+	//      fprintf(f, "NetName = %s\n", netname);
 	fprintf(f, "ConnectTo = %s\n", mesh->self->name);
 
 	// Copy Broadcast and Mode
@@ -1456,7 +1678,7 @@ char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
 		char buf[1024];
 		while(fgets(buf, sizeof buf, tc)) {
 			if((!strncasecmp(buf, "Mode", 4) && strchr(" \t=", buf[4]))
-					|| (!strncasecmp(buf, "Broadcast", 9) && strchr(" \t=", buf[9]))) {
+			                || (!strncasecmp(buf, "Broadcast", 9) && strchr(" \t=", buf[9]))) {
 				fputs(buf, f);
 				// Make sure there is a newline character.
 				if(!strchr(buf, '\n'))
@@ -1492,7 +1714,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
-	
+
 	pthread_mutex_lock(&(mesh->mesh_mutex));
 
 	//TODO: think of a better name for this variable, or of a different way to tokenize the invitation URL.
@@ -1543,9 +1765,8 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	char *b64key = ecdsa_get_base64_public_key(key);
 
 	//Before doing meshlink_join make sure we are not connected to another mesh
-	if ( mesh->threadstarted ){
+	if(mesh->threadstarted)
 		goto invalid;
-	}
 
 	// Connect to the meshlink daemon mentioned in the URL.
 	struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
@@ -1564,6 +1785,8 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 		return false;
 	}
 
+	set_timeout(mesh->sock, 5000);
+
 	if(connect(mesh->sock, ai->ai_addr, ai->ai_addrlen)) {
 		logger(mesh, MESHLINK_DEBUG, "Could not connect to %s port %s: %s\n", address, port, strerror(errno));
 		closesocket(mesh->sock);
@@ -1627,7 +1850,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	}
 
 	// Start an SPTPS session
-	if(!sptps_start(&mesh->sptps, mesh, true, false, key, hiskey, "meshlink invitation", 15, invitation_send, invitation_receive)) {
+	if(!sptps_start(&mesh->sptps, mesh, true, false, key, hiskey, meshlink_invitation_label, sizeof meshlink_invitation_label, invitation_send, invitation_receive)) {
 		meshlink_errno = MESHLINK_EINTERNAL;
 		pthread_mutex_unlock(&(mesh->mesh_mutex));
 		return false;
@@ -1688,7 +1911,7 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 	}
 
 	pthread_mutex_lock(&(mesh->mesh_mutex));
-	
+
 	char filename[PATH_MAX];
 	snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
 	FILE *f = fopen(filename, "r");
@@ -1716,7 +1939,7 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 
 	fclose(f);
 	buf[len - 1] = 0;
-	
+
 	pthread_mutex_unlock(&(mesh->mesh_mutex));
 	return buf;
 }
@@ -1726,7 +1949,7 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
-	
+
 	pthread_mutex_lock(&(mesh->mesh_mutex));
 
 	if(strncmp(data, "Name = ", 7)) {
@@ -1795,7 +2018,7 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	}
 
 	pthread_mutex_lock(&(mesh->mesh_mutex));
-	
+
 	node_t *n;
 	n = (node_t*)node;
 	n->status.blacklisted=true;
@@ -1815,7 +2038,7 @@ void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	}
 
 	pthread_mutex_lock(&(mesh->mesh_mutex));
-	
+
 	node_t *n = (node_t *)node;
 	n->status.blacklisted = false;
 
@@ -1825,21 +2048,29 @@ void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	return;
 }
 
+void meshlink_set_default_blacklist(meshlink_handle_t *mesh, bool blacklist) {
+	mesh->default_blacklist = blacklist;
+}
+
 /* Hint that a hostname may be found at an address
  * See header file for detailed comment.
  */
 void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const struct sockaddr *addr) {
 	if(!mesh || !node || !addr)
 		return;
-	
+
+	// Ignore hints about ourself.
+	if((node_t *)node == mesh->self)
+		return;
+
 	pthread_mutex_lock(&(mesh->mesh_mutex));
-	
+
 	char *host = NULL, *port = NULL, *str = NULL;
 	sockaddr2str((const sockaddr_t *)addr, &host, &port);
 
 	if(host && port) {
 		xasprintf(&str, "%s %s", host, port);
-		if ( (strncmp ("fe80",host,4) != 0) && ( strncmp("127.",host,4) != 0 ) && ( strcmp("localhost",host) !=0 ) )
+		if((strncmp("fe80",host,4) != 0) && (strncmp("127.",host,4) != 0) && (strcmp("localhost",host) !=0))
 			append_config_file(mesh, node->name, "Address", str);
 		else
 			logger(mesh, MESHLINK_DEBUG, "Not adding Link Local IPv6 Address to config\n");
@@ -1864,7 +2095,7 @@ meshlink_edge_t **meshlink_get_all_edges_state(meshlink_handle_t *mesh, meshlink
 	}
 
 	pthread_mutex_lock(&(mesh->mesh_mutex));
-	
+
 	meshlink_edge_t **result = NULL;
 	meshlink_edge_t *copy = NULL;
 	int result_size = 0;
@@ -1872,11 +2103,10 @@ meshlink_edge_t **meshlink_get_all_edges_state(meshlink_handle_t *mesh, meshlink
 	result_size = mesh->edges->count;
 
 	// if result is smaller than edges, we have to dealloc all the excess meshlink_edge_t
-	if(result_size > *nmemb) {
-		result = realloc(edges, result_size * sizeof (meshlink_edge_t*));
-	} else {
+	if(result_size > *nmemb)
+		result = realloc(edges, result_size * sizeof(meshlink_edge_t*));
+	else
 		result = edges;
-	}
 
 	if(result) {
 		meshlink_edge_t **p = result;
@@ -1889,12 +2119,10 @@ meshlink_edge_t **meshlink_get_all_edges_state(meshlink_handle_t *mesh, meshlink
 			}
 			n++;
 			// the first *nmemb members of result can be re-used
-			if(n > *nmemb) {
+			if(n > *nmemb)
 				copy = xzalloc(sizeof *copy);
-			}
-			else {
+			else
 				copy = *p;
-			}
 			copy->from = (meshlink_node_t*)e->from;
 			copy->to = (meshlink_node_t*)e->to;
 			copy->address = e->address.storage;
@@ -1903,14 +2131,12 @@ meshlink_edge_t **meshlink_get_all_edges_state(meshlink_handle_t *mesh, meshlink
 			*p++ = copy;
 		}
 		// shrink result to the actual amount of memory used
-		for(int i = *nmemb; i > result_size; i--) {
+		for(int i = *nmemb; i > result_size; i--)
 			free(result[i - 1]);
-		}
-		result = realloc(result, result_size * sizeof (meshlink_edge_t*));
+		result = realloc(result, result_size * sizeof(meshlink_edge_t*));
 		*nmemb = result_size;
 	} else {
 		*nmemb = 0;
-		free(result);
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
@@ -1930,12 +2156,9 @@ static ssize_t channel_recv(struct utcp_connection *connection, const void *data
 		abort();
 	node_t *n = channel->node;
 	meshlink_handle_t *mesh = n->mesh;
-	if(!channel->receive_cb)
-		return -1;
-	else {
+	if(channel->receive_cb)
 		channel->receive_cb(mesh, channel, data, len);
-		return len;
-	}
+	return len;
 }
 
 static void channel_accept(struct utcp_connection *utcp_connection, uint16_t port) {
@@ -1957,13 +2180,15 @@ static void channel_accept(struct utcp_connection *utcp_connection, uint16_t por
 static ssize_t channel_send(struct utcp *utcp, const void *data, size_t len) {
 	node_t *n = utcp->priv;
 	meshlink_handle_t *mesh = n->mesh;
-	char hex[len * 2 + 1];
-	bin2hex(data, hex, len);
-	logger(mesh, MESHLINK_WARNING, "channel_send(%p, %p, %zu): %s\n", utcp, data, len, hex);
 	return meshlink_send(mesh, (meshlink_node_t *)n, data, len) ? len : -1;
 }
 
 void meshlink_set_channel_receive_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_receive_cb_t cb) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
 	channel->receive_cb = cb;
 }
 
@@ -1971,9 +2196,6 @@ static void channel_receive(meshlink_handle_t *mesh, meshlink_node_t *source, co
 	node_t *n = (node_t *)source;
 	if(!n->utcp)
 		abort();
-	char hex[len * 2 + 1];
-	bin2hex(data, hex, len);
-	logger(mesh, MESHLINK_WARNING, "channel_receive(%p, %p, %zu): %s\n", n->utcp, data, len, hex);
 	utcp_recv(n->utcp, data, len);
 }
 
@@ -1993,23 +2215,27 @@ void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *c
 }
 
 void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
 	pthread_mutex_lock(&mesh->mesh_mutex);
 	mesh->channel_accept_cb = cb;
 	mesh->receive_cb = channel_receive;
 	for splay_each(node_t, n, mesh->nodes) {
-		if(!n->utcp && n != mesh->self) {
-			logger(mesh, MESHLINK_WARNING, "utcp_init on node %s", n->name);
+		if(!n->utcp && n != mesh->self)
 			n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
-		}
 	}
 	pthread_mutex_unlock(&mesh->mesh_mutex);
 }
 
-void meshlink_channel_init(meshlink_handle_t *mesh) {
-}
+meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_node_t *node, uint16_t port, meshlink_channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags) {
+	if(!mesh || !node) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
 
-meshlink_channel_t *meshlink_channel_open(meshlink_handle_t *mesh, meshlink_node_t *node, uint16_t port, meshlink_channel_receive_cb_t cb, const void *data, size_t len) {
-	logger(mesh, MESHLINK_WARNING, "meshlink_channel_open(%p, %s, %u, %p, %p, %zu)\n", mesh, node->name, port, cb, data, len);
 	node_t *n = (node_t *)node;
 	if(!n->utcp) {
 		n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
@@ -2022,7 +2248,7 @@ meshlink_channel_t *meshlink_channel_open(meshlink_handle_t *mesh, meshlink_node
 	meshlink_channel_t *channel = xzalloc(sizeof *channel);
 	channel->node = n;
 	channel->receive_cb = cb;
-	channel->c = utcp_connect(n->utcp, port, channel_recv, channel);
+	channel->c = utcp_connect_ex(n->utcp, port, channel_recv, channel, flags);
 	if(!channel->c) {
 		meshlink_errno = errno == ENOMEM ? MESHLINK_ENOMEM : MESHLINK_EINTERNAL;
 		free(channel);
@@ -2031,21 +2257,64 @@ meshlink_channel_t *meshlink_channel_open(meshlink_handle_t *mesh, meshlink_node
 	return channel;
 }
 
+meshlink_channel_t *meshlink_channel_open(meshlink_handle_t *mesh, meshlink_node_t *node, uint16_t port, meshlink_channel_receive_cb_t cb, const void *data, size_t len) {
+	return meshlink_channel_open_ex(mesh, node, port, cb, data, len, MESHLINK_CHANNEL_TCP);
+}
+
 void meshlink_channel_shutdown(meshlink_handle_t *mesh, meshlink_channel_t *channel, int direction) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
 	utcp_shutdown(channel->c, direction);
 }
 
 void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
 	utcp_close(channel->c);
 	free(channel);
 }
 
 ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len) {
-	// TODO: locking.
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	if(!len)
+		return 0;
+
+	if(!data) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	// TODO: more finegrained locking.
 	// Ideally we want to put the data into the UTCP connection's send buffer.
 	// Then, preferrably only if there is room in the receiver window,
 	// kick the meshlink thread to go send packets.
-	return utcp_send(channel->c, data, len);
+
+	pthread_mutex_lock(&mesh->mesh_mutex);
+	ssize_t retval = utcp_send(channel->c, data, len);
+	pthread_mutex_unlock(&mesh->mesh_mutex);
+
+	if(retval < 0)
+		meshlink_errno = MESHLINK_ENETWORK;
+	return retval;
+}
+
+uint32_t meshlink_channel_get_flags(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	return channel->c->flags;
 }
 
 void update_node_status(meshlink_handle_t *mesh, node_t *n) {
@@ -2055,8 +2324,35 @@ void update_node_status(meshlink_handle_t *mesh, node_t *n) {
 		mesh->node_status_cb(mesh, (meshlink_node_t *)n, n->status.reachable);
 }
 
+void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mesh_mutex);
+
+	if(mesh->discovery == enable)
+		goto end;
+
+	if(mesh->threadstarted) {
+		if(enable)
+			discovery_start(mesh);
+		else
+			discovery_stop(mesh);
+	}
+
+	mesh->discovery = enable;
+
+end:
+	pthread_mutex_unlock(&mesh->mesh_mutex);
+}
+
 static void __attribute__((constructor)) meshlink_init(void) {
 	crypto_init();
+	unsigned int seed;
+	randomize(&seed, sizeof seed);
+	srand(seed);
 }
 
 static void __attribute__((destructor)) meshlink_exit(void) {
@@ -2065,8 +2361,8 @@ static void __attribute__((destructor)) meshlink_exit(void) {
 
 /// Device class traits
 dev_class_traits_t dev_class_traits[_DEV_CLASS_MAX +1] = {
-	{ .min_connects = 3, .max_connects = 10000, .edge_weight = 1 },	// DEV_CLASS_BACKBONE
-	{ .min_connects = 3, .max_connects = 100, .edge_weight = 3 },	// DEV_CLASS_STATIONARY
-	{ .min_connects = 3, .max_connects = 3, .edge_weight = 6 },		// DEV_CLASS_PORTABLE
-	{ .min_connects = 1, .max_connects = 1, .edge_weight = 9 },		// DEV_CLASS_UNKNOWN
+	{ .min_connects = 3, .max_connects = 10000, .edge_weight = 1 }, // DEV_CLASS_BACKBONE
+	{ .min_connects = 3, .max_connects = 100, .edge_weight = 3 },   // DEV_CLASS_STATIONARY
+	{ .min_connects = 3, .max_connects = 3, .edge_weight = 6 },             // DEV_CLASS_PORTABLE
+	{ .min_connects = 1, .max_connects = 1, .edge_weight = 9 },             // DEV_CLASS_UNKNOWN
 };