X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fmeshlink.c;h=d3cf36ad5e5801fdaae0d8591520841cea230385;hb=61701fc35b1708fba93e7559e34339937bbc26ff;hp=7c5bbd22741476532e0d17cdfbe992a7e2056276;hpb=64db0bb3f32236b55746bf62002faca08a54e364;p=meshlink

diff --git a/src/meshlink.c b/src/meshlink.c
index 7c5bbd22..d3cf36ad 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -154,7 +154,7 @@ 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);
+		assert(pthread_join(thr, NULL) == 0);
 	}
 
 	return params.fd;
@@ -167,7 +167,7 @@ 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,
@@ -204,7 +204,7 @@ 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);
 
@@ -257,7 +257,7 @@ char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int fami
 	}
 
 	logger(mesh, MESHLINK_DEBUG, "Trying to discover externally visible hostname...\n");
-	struct addrinfo *ai = adns_blocking_request(mesh, xstrdup(host), xstrdup(port ? port : "80"), 5);
+	struct addrinfo *ai = adns_blocking_request(mesh, xstrdup(host), xstrdup(port ? port : "80"), SOCK_STREAM, 5);
 	char line[256];
 	char *hostname = NULL;
 
@@ -386,7 +386,7 @@ 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;
@@ -501,7 +501,7 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
 		}
 
 		// Convert what we have to a sockaddr
-		struct addrinfo *ai_in = adns_blocking_request(mesh, xstrdup(hostname[i]), xstrdup(port[i]), 5);
+		struct addrinfo *ai_in = adns_blocking_request(mesh, xstrdup(hostname[i]), xstrdup(port[i]), SOCK_STREAM, 5);
 
 		if(!ai_in) {
 			continue;
@@ -710,39 +710,39 @@ 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);
@@ -888,7 +888,7 @@ 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;
@@ -1213,7 +1213,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	// Create hash for the new key
 	void *new_config_key;
@@ -1222,7 +1222,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!prf(new_key, new_keylen, "MeshLink configuration key", 26, new_config_key, CHACHA_POLY1305_KEYLEN)) {
 		logger(mesh, MESHLINK_ERROR, "Error creating new configuration key!\n");
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1231,7 +1231,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!config_copy(mesh, "current", mesh->config_key, "new", new_config_key)) {
 		logger(mesh, MESHLINK_ERROR, "Could not set up configuration in %s/old: %s\n", mesh->confbase, strerror(errno));
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1242,7 +1242,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!config_rename(mesh, "current", "old")) {
 		logger(mesh, MESHLINK_ERROR, "Cannot rename %s/current to %s/old\n", mesh->confbase, mesh->confbase);
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1253,7 +1253,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!config_rename(mesh, "new", "current")) {
 		logger(mesh, MESHLINK_ERROR, "Cannot rename %s/new to %s/current\n", mesh->confbase, mesh->confbase);
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1262,7 +1262,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	// Cleanup the "old" confbase sub-directory
 
 	if(!config_destroy(mesh->confbase, "old")) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1271,7 +1271,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	free(mesh->config_key);
 	mesh->config_key = new_config_key;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -1456,11 +1456,17 @@ 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);
-	pthread_mutex_init(&mesh->mutex, &attr);
+	assert(pthread_mutexattr_init(&attr) == 0);
+	assert(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) == 0);
+	assert(pthread_mutex_init(&mesh->mutex, &attr) == 0);
+	assert(pthread_cond_init(&mesh->cond, NULL) == 0);
+
+	assert(pthread_mutex_init(&mesh->discovery_mutex, NULL) == 0);
+	assert(pthread_cond_init(&mesh->discovery_cond, NULL) == 0);
+
+	assert(pthread_cond_init(&mesh->adns_cond, NULL) == 0);
 
 	mesh->threadstarted = false;
 	event_loop_init(&mesh->loop);
@@ -1560,11 +1566,11 @@ meshlink_submesh_t *meshlink_submesh_open(meshlink_handle_t  *mesh, const char *
 	}
 
 	//lock mesh->nodes
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	s = (meshlink_submesh_t *)create_submesh(mesh, submesh);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return s;
 }
@@ -1576,12 +1582,12 @@ static void *meshlink_main_loop(void *arg) {
 #ifdef HAVE_SETNS
 
 		if(setns(mesh->netns, CLONE_NEWNET) != 0) {
-			pthread_cond_signal(&mesh->cond);
+			assert(pthread_cond_signal(&mesh->cond) == 0);
 			return NULL;
 		}
 
 #else
-		pthread_cond_signal(&mesh->cond);
+		assert(pthread_cond_signal(&mesh->cond) == 0);
 		return NULL;
 #endif // HAVE_SETNS
 	}
@@ -1594,14 +1600,14 @@ static void *meshlink_main_loop(void *arg) {
 
 #endif
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Starting main_loop...\n");
-	pthread_cond_broadcast(&mesh->cond);
+	assert(pthread_cond_broadcast(&mesh->cond) == 0);
 	main_loop(mesh);
 	logger(mesh, MESHLINK_DEBUG, "main_loop returned.\n");
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 #if HAVE_CATTA
 
@@ -1623,7 +1629,7 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	logger(mesh, MESHLINK_DEBUG, "meshlink_start called\n");
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	assert(mesh->self);
 	assert(mesh->private_key);
@@ -1632,7 +1638,7 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	if(mesh->threadstarted) {
 		logger(mesh, MESHLINK_DEBUG, "thread was already running\n");
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return true;
 	}
 
@@ -1648,7 +1654,7 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 	if(!mesh->name) {
 		logger(mesh, MESHLINK_DEBUG, "No name given!\n");
 		meshlink_errno = MESHLINK_EINVAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1659,22 +1665,27 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	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;
+	assert(pthread_attr_init(&attr) == 0);
+	assert(pthread_attr_setstacksize(&attr, 1024 * 1024) == 0);
+
+	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;
 		event_loop_stop(&mesh->loop);
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_cond_wait(&mesh->cond, &mesh->mutex);
+	assert(pthread_cond_wait(&mesh->cond, &mesh->mutex) == 0);
 	mesh->threadstarted = true;
 
 	// Ensure we are considered reachable
 	graph(mesh);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return true;
 }
 
@@ -1684,7 +1695,7 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	logger(mesh, MESHLINK_DEBUG, "meshlink_stop called\n");
 
 	// Shut down the main thread
@@ -1707,9 +1718,9 @@ 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);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
+		assert(pthread_join(mesh->thread, NULL) == 0);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 		mesh->threadstarted = false;
 	}
@@ -1741,7 +1752,7 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		}
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_close(meshlink_handle_t *mesh) {
@@ -1754,7 +1765,7 @@ void meshlink_close(meshlink_handle_t *mesh) {
 	meshlink_stop(mesh);
 
 	// lock is not released after this
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	// Close and free all resources used.
 
@@ -1798,8 +1809,8 @@ void meshlink_close(meshlink_handle_t *mesh) {
 
 	main_config_unlock(mesh);
 
-	pthread_mutex_unlock(&mesh->mutex);
-	pthread_mutex_destroy(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
+	assert(pthread_mutex_destroy(&mesh->mutex) == 0);
 
 	memset(mesh, 0, sizeof(*mesh));
 
@@ -1875,9 +1886,9 @@ void meshlink_set_receive_cb(meshlink_handle_t *mesh, meshlink_receive_cb_t cb)
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->receive_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_connection_try_cb(meshlink_handle_t *mesh, meshlink_connection_try_cb_t cb) {
@@ -1886,9 +1897,9 @@ void meshlink_set_connection_try_cb(meshlink_handle_t *mesh, meshlink_connection
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->connection_try_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_cb_t cb) {
@@ -1897,9 +1908,9 @@ void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->node_status_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_node_pmtu_cb(meshlink_handle_t *mesh, meshlink_node_pmtu_cb_t cb) {
@@ -1908,9 +1919,9 @@ void meshlink_set_node_pmtu_cb(meshlink_handle_t *mesh, meshlink_node_pmtu_cb_t
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->node_pmtu_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_duplicate_cb_t cb) {
@@ -1919,17 +1930,17 @@ void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_dupli
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->node_duplicate_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 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);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 		mesh->log_cb = cb;
 		mesh->log_level = cb ? level : 0;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	} else {
 		global_log_cb = cb;
 		global_log_level = cb ? level : 0;
@@ -1942,9 +1953,9 @@ void meshlink_set_error_cb(struct meshlink_handle *mesh, meshlink_error_cb_t cb)
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->error_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 static bool prepare_packet(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len, vpn_packet_t *packet) {
@@ -2062,19 +2073,19 @@ ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination)
 		return -1;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)destination;
 
 	if(!n->status.reachable) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return 0;
 
 	} else if(n->mtuprobes > 30 && n->minmtu) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return n->minmtu;
 	} else {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return MTU;
 	}
 }
@@ -2085,13 +2096,13 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return NULL;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 
 	if(!node_read_public_key(mesh, n) || !n->ecdsa) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -2101,7 +2112,7 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		meshlink_errno = MESHLINK_EINTERNAL;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return fingerprint;
 }
 
@@ -2122,9 +2133,9 @@ meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
 
 	node_t *n = NULL;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	n = lookup_node(mesh, (char *)name); // TODO: make lookup_node() use const
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!n) {
 		meshlink_errno = MESHLINK_ENOENT;
@@ -2141,9 +2152,9 @@ meshlink_submesh_t *meshlink_get_submesh(meshlink_handle_t *mesh, const char *na
 
 	meshlink_submesh_t *submesh = NULL;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	submesh = (meshlink_submesh_t *)lookup_submesh(mesh, name);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!submesh) {
 		meshlink_errno = MESHLINK_ENOENT;
@@ -2161,7 +2172,7 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	*nmemb = mesh->nodes->count;
 	result = realloc(nodes, *nmemb * sizeof(*nodes));
@@ -2178,7 +2189,7 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return result;
 }
@@ -2186,7 +2197,7 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	*nmemb = 0;
 
@@ -2198,7 +2209,7 @@ static meshlink_node_t **meshlink_get_all_nodes_by_condition(meshlink_handle_t *
 
 	if(*nmemb == 0) {
 		free(nodes);
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2218,7 +2229,7 @@ static meshlink_node_t **meshlink_get_all_nodes_by_condition(meshlink_handle_t *
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return result;
 }
@@ -2303,11 +2314,11 @@ dev_class_t meshlink_get_node_dev_class(meshlink_handle_t *mesh, meshlink_node_t
 
 	dev_class_t devclass;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	devclass = ((node_t *)node)->devclass;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return devclass;
 }
@@ -2336,7 +2347,7 @@ bool meshlink_get_node_reachability(struct meshlink_handle *mesh, struct meshlin
 	node_t *n = (node_t *)node;
 	bool reachable;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	reachable = n->status.reachable && !n->status.blacklisted;
 
 	if(last_reachable) {
@@ -2347,7 +2358,7 @@ bool meshlink_get_node_reachability(struct meshlink_handle *mesh, struct meshlin
 		*last_unreachable = n->last_unreachable;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return reachable;
 }
@@ -2363,16 +2374,16 @@ bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!ecdsa_sign(mesh->private_key, data, len, signature)) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
 	*siglen = MESHLINK_SIGLEN;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return true;
 }
 
@@ -2387,7 +2398,7 @@ bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const voi
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	bool rval = false;
 
@@ -2400,12 +2411,12 @@ bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const voi
 		rval = ecdsa_verify(((struct node_t *)source)->ecdsa, data, len, signature);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return rval;
 }
 
 static bool refresh_invitation_key(meshlink_handle_t *mesh) {
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	size_t count = invitation_purge_old(mesh, time(NULL) - mesh->invitation_timeout);
 
@@ -2413,7 +2424,7 @@ static bool refresh_invitation_key(meshlink_handle_t *mesh) {
 		// TODO: Update invitation key if necessary?
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return mesh->invitation_key;
 }
@@ -2451,18 +2462,18 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
 		canonical_address = xstrdup(address);
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 	free(n->canonical_address);
 	n->canonical_address = canonical_address;
 
 	if(!node_write_config(mesh, n)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return config_sync(mesh, "current");
 }
@@ -2493,14 +2504,14 @@ bool meshlink_add_invitation_address(struct meshlink_handle *mesh, const char *a
 		combo = xstrdup(address);
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	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);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -2511,14 +2522,14 @@ void meshlink_clear_invitation_addresses(struct meshlink_handle *mesh) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(mesh->invitation_addresses) {
 		list_delete_list(mesh->invitation_addresses);
 		mesh->invitation_addresses = NULL;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 bool meshlink_add_address(meshlink_handle_t *mesh, const char *address) {
@@ -2556,9 +2567,9 @@ int meshlink_get_port(meshlink_handle_t *mesh) {
 
 	int port;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	port = atoi(mesh->myport);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return port;
 }
@@ -2582,7 +2593,7 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 
 	bool rval = false;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(mesh->threadstarted) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -2623,7 +2634,7 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 	rval = config_sync(mesh, "current");
 
 done:
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return rval && meshlink_get_port(mesh) == port;
 }
@@ -2652,13 +2663,13 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	// Check validity of the new node's name
 	if(!check_id(name)) {
 		logger(mesh, MESHLINK_ERROR, "Invalid name for node.\n");
 		meshlink_errno = MESHLINK_EINVAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2666,7 +2677,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(config_exists(mesh, "current", name)) {
 		logger(mesh, MESHLINK_ERROR, "A host config file for %s already exists!\n", name);
 		meshlink_errno = MESHLINK_EEXIST;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2674,7 +2685,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(lookup_node(mesh, name)) {
 		logger(mesh, MESHLINK_ERROR, "A node with name %s is already known!\n", name);
 		meshlink_errno = MESHLINK_EEXIST;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2684,13 +2695,13 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(!address) {
 		logger(mesh, MESHLINK_ERROR, "No Address known for ourselves!\n");
 		meshlink_errno = MESHLINK_ERESOLV;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
 	if(!refresh_invitation_key(mesh)) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2698,7 +2709,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(mesh->self->status.dirty) {
 		if(!node_write_config(mesh, mesh->self)) {
 			logger(mesh, MESHLINK_ERROR, "Could not write our own host config file!\n");
-			pthread_mutex_unlock(&mesh->mutex);
+			assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 			return NULL;
 		}
 	}
@@ -2760,7 +2771,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(!invitation_write(mesh, "current", cookiehash, &config, mesh->config_key)) {
 		logger(mesh, MESHLINK_DEBUG, "Could not create invitation file %s: %s\n", cookiehash, strerror(errno));
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2769,7 +2780,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	xasprintf(&url, "%s/%s%s", address, hash, cookie);
 	free(address);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return url;
 }
 
@@ -2794,7 +2805,7 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	//Before doing meshlink_join make sure we are not connected to another mesh
 	if(mesh->threadstarted) {
@@ -2882,11 +2893,11 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 		}
 
 		// Connect to the meshlink daemon mentioned in the URL.
-		struct addrinfo *ai = adns_blocking_request(mesh, xstrdup(address), xstrdup(port), 5);
+		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));
@@ -3012,7 +3023,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	ecdsa_free(key);
 	closesocket(state.sock);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return true;
 
 invalid:
@@ -3027,7 +3038,7 @@ exit:
 		closesocket(state.sock);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return false;
 }
 
@@ -3045,7 +3056,7 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 	packmsg_add_str(&out, mesh->name);
 	packmsg_add_str(&out, CORE_MESH);
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	packmsg_add_int32(&out, mesh->self->devclass);
 	packmsg_add_bool(&out, mesh->self->status.blacklisted);
@@ -3079,7 +3090,7 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 	packmsg_add_int64(&out, 0);
 	packmsg_add_int64(&out, 0);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!packmsg_output_ok(&out)) {
 		logger(mesh, MESHLINK_DEBUG, "Error creating export data\n");
@@ -3133,17 +3144,17 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	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);
 
@@ -3169,7 +3180,7 @@ 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);
@@ -3189,7 +3200,7 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		node_add(mesh, n);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	free(buf);
 
@@ -3257,14 +3268,14 @@ bool meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!blacklist(mesh, (node_t *)node)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", node->name);
 	return true;
@@ -3276,7 +3287,7 @@ bool meshlink_blacklist_by_name(meshlink_handle_t *mesh, const char *name) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = lookup_node(mesh, (char *)name);
 
@@ -3287,11 +3298,11 @@ bool meshlink_blacklist_by_name(meshlink_handle_t *mesh, const char *name) {
 	}
 
 	if(!blacklist(mesh, (node_t *)n)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", name);
 	return true;
@@ -3325,14 +3336,14 @@ bool meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!whitelist(mesh, (node_t *)node)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Whitelisted %s.\n", node->name);
 	return true;
@@ -3344,7 +3355,7 @@ bool meshlink_whitelist_by_name(meshlink_handle_t *mesh, const char *name) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = lookup_node(mesh, (char *)name);
 
@@ -3355,11 +3366,11 @@ bool meshlink_whitelist_by_name(meshlink_handle_t *mesh, const char *name) {
 	}
 
 	if(!whitelist(mesh, (node_t *)n)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Whitelisted %s.\n", name);
 	return true;
@@ -3377,18 +3388,18 @@ bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
 
 	node_t *n = (node_t *)node;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Check that the node is not reachable */
 	if(n->status.reachable || n->connection) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		logger(mesh, MESHLINK_WARNING, "Could not forget %s: still reachable", n->name);
 		return false;
 	}
 
 	/* Check that we don't have any active UTCP connections */
 	if(n->utcp && utcp_is_active(n->utcp)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		logger(mesh, MESHLINK_WARNING, "Could not forget %s: active UTCP connections", n->name);
 		return false;
 	}
@@ -3396,7 +3407,7 @@ bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	/* Check that we have no active connections to this node */
 	for list_each(connection_t, c, mesh->connections) {
 		if(c->node == n) {
-			pthread_mutex_unlock(&mesh->mutex);
+			assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 			logger(mesh, MESHLINK_WARNING, "Could not forget %s: active connection", n->name);
 			return false;
 		}
@@ -3406,21 +3417,21 @@ 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);
 			}
 		}
 	}
 
 	/* Delete the config file for this node */
 	if(!config_delete(mesh, "current", n->name)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
 	/* Delete the node struct and any remaining edges referencing this node */
 	node_del(mesh, n);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return config_sync(mesh, "current");
 }
@@ -3434,7 +3445,7 @@ void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 
@@ -3444,7 +3455,7 @@ void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const
 		}
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	// @TODO do we want to fire off a connection attempt right away?
 }
 
@@ -3465,7 +3476,7 @@ static bool aio_finish_one(meshlink_handle_t *mesh, meshlink_channel_t *channel,
 
 		if(aio->data) {
 			if(aio->cb.buffer) {
-				aio->cb.buffer(mesh, channel, aio->data, aio->len, aio->priv);
+				aio->cb.buffer(mesh, channel, aio->data, aio->done, aio->priv);
 			}
 		} else {
 			if(aio->cb.fd) {
@@ -3675,6 +3686,11 @@ static void channel_poll(struct utcp_connection *connection, size_t len) {
 		if(aio->data) {
 			sent = utcp_send(connection, (char *)aio->data + aio->done, todo);
 		} else {
+			/* 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);
 
@@ -3701,7 +3717,7 @@ static void channel_poll(struct utcp_connection *connection, size_t len) {
 
 		if(sent != (ssize_t)todo) {
 			/* We should never get a partial send at this point */
-			assert(sent < 0);
+			assert(sent <= 0);
 
 			/* Sending failed, abort all outstanding AIO buffers and send a poll callback. */
 			if(!aio_abort(mesh, channel, &channel->aio_send)) {
@@ -3743,10 +3759,10 @@ void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	channel->poll_cb = cb;
 	utcp_set_poll_cb(channel->c, (cb || channel->aio_send) ? channel_poll : NULL);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb) {
@@ -3755,7 +3771,7 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->channel_accept_cb = cb;
 	mesh->receive_cb = channel_receive;
 
@@ -3767,7 +3783,7 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 		}
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_channel_sndbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
@@ -3778,9 +3794,9 @@ void meshlink_set_channel_sndbuf(meshlink_handle_t *mesh, meshlink_channel_t *ch
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	utcp_set_sndbuf(channel->c, size);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
@@ -3791,9 +3807,9 @@ void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *ch
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	utcp_set_rcvbuf(channel->c, size);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 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) {
@@ -3806,7 +3822,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 		return NULL;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 
@@ -3818,7 +3834,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 
 		if(!n->utcp) {
 			meshlink_errno = errno == ENOMEM ? MESHLINK_ENOMEM : MESHLINK_EINTERNAL;
-			pthread_mutex_unlock(&mesh->mutex);
+			assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 			return NULL;
 		}
 	}
@@ -3826,7 +3842,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 	if(n->status.blacklisted) {
 		logger(mesh, MESHLINK_ERROR, "Cannot open a channel with blacklisted node\n");
 		meshlink_errno = MESHLINK_EBLACKLISTED;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -3840,7 +3856,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 
 	channel->c = utcp_connect_ex(n->utcp, port, channel_recv, channel, flags);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!channel->c) {
 		meshlink_errno = errno == ENOMEM ? MESHLINK_ENOMEM : MESHLINK_EINTERNAL;
@@ -3861,9 +3877,9 @@ void meshlink_channel_shutdown(meshlink_handle_t *mesh, meshlink_channel_t *chan
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	utcp_shutdown(channel->c, direction);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
@@ -3872,7 +3888,7 @@ void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(channel->c) {
 		utcp_close(channel->c);
@@ -3887,7 +3903,7 @@ void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel
 		free(channel);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len) {
@@ -3912,7 +3928,7 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 
 	ssize_t retval;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Disallow direct calls to utcp_send() while we still have AIO active. */
 	if(channel->aio_send) {
@@ -3921,7 +3937,7 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 		retval = utcp_send(channel->c, data, len);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(retval < 0) {
 		meshlink_errno = MESHLINK_ENETWORK;
@@ -3947,7 +3963,7 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_send;
@@ -3966,7 +3982,7 @@ bool meshlink_channel_aio_send(meshlink_handle_t *mesh, meshlink_channel_t *chan
 		channel_poll(channel->c, todo);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -3988,7 +4004,7 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_send;
@@ -4007,7 +4023,7 @@ bool meshlink_channel_aio_fd_send(meshlink_handle_t *mesh, meshlink_channel_t *c
 		channel_poll(channel->c, left);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -4029,7 +4045,7 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_receive;
@@ -4040,7 +4056,7 @@ bool meshlink_channel_aio_receive(meshlink_handle_t *mesh, meshlink_channel_t *c
 
 	*p = aio;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -4062,7 +4078,7 @@ 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);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_receive;
@@ -4073,7 +4089,7 @@ bool meshlink_channel_aio_fd_receive(meshlink_handle_t *mesh, meshlink_channel_t
 
 	*p = aio;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -4122,7 +4138,7 @@ void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t
 
 	node_t *n = (node_t *)node;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!n->utcp) {
 		n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
@@ -4132,7 +4148,7 @@ void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t
 
 	utcp_set_user_timeout(n->utcp, timeout);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void update_node_status(meshlink_handle_t *mesh, node_t *n) {
@@ -4176,7 +4192,7 @@ void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(mesh->discovery == enable) {
 		goto end;
@@ -4193,7 +4209,7 @@ void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
 	mesh->discovery = enable;
 
 end:
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 #else
 	(void)mesh;
 	(void)enable;
@@ -4212,10 +4228,10 @@ void meshlink_set_dev_class_timeouts(meshlink_handle_t *mesh, dev_class_t devcla
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->dev_class_traits[devclass].pinginterval = pinginterval;
 	mesh->dev_class_traits[devclass].pingtimeout = pingtimeout;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_dev_class_fast_retry_period(meshlink_handle_t *mesh, dev_class_t devclass, int fast_retry_period) {
@@ -4229,9 +4245,9 @@ void meshlink_set_dev_class_fast_retry_period(meshlink_handle_t *mesh, dev_class
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->dev_class_traits[devclass].fast_retry_period = fast_retry_period;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, bool inviter_commits_first) {
@@ -4240,9 +4256,9 @@ extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, boo
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->inviter_commits_first = inviter_commits_first;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_external_address_discovery_url(struct meshlink_handle *mesh, const char *url) {
@@ -4256,10 +4272,10 @@ void meshlink_set_external_address_discovery_url(struct meshlink_handle *mesh, c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	free(mesh->external_address_url);
 	mesh->external_address_url = url ? xstrdup(url) : NULL;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_scheduling_granularity(struct meshlink_handle *mesh, long granularity) {
@@ -4281,7 +4297,7 @@ void handle_network_change(meshlink_handle_t *mesh, bool online) {
 	retry(mesh);
 }
 
-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;
@@ -4292,7 +4308,7 @@ 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);
 	}
 }