X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fmeshlink.c;h=75458fe6940ed221059e39b29035a2f84de6ccc8;hb=fe5563f92021618b4a8b41e412c73d8364fcaf6e;hp=e82ea4f11a384f639f3c6298a42bfa15aecf3e8a;hpb=03ab29c1e6e1b608311decb6630eb0a2177ce1dd;p=meshlink

diff --git a/src/meshlink.c b/src/meshlink.c
index e82ea4f1..75458fe6 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -796,6 +796,7 @@ static const char *errstr[] = {
 	[MESHLINK_EPEER] = "Error communicating with peer",
 	[MESHLINK_ENOTSUP] = "Operation not supported",
 	[MESHLINK_EBUSY] = "MeshLink instance already in use",
+	[MESHLINK_EBLACKLISTED] = "Node is blacklisted",
 };
 
 const char *meshlink_strerror(meshlink_errno_t err) {
@@ -889,6 +890,7 @@ static bool meshlink_setup(meshlink_handle_t *mesh) {
 	mesh->self->name = xstrdup(mesh->name);
 	mesh->self->devclass = mesh->devclass;
 	mesh->self->ecdsa = ecdsa_set_public_key(ecdsa_get_public_key(mesh->private_key));
+	mesh->self->session_id = mesh->session_id;
 
 	if(!write_main_config_files(mesh)) {
 		logger(mesh, MESHLINK_ERROR, "Could not write main config files into %s/current: %s\n", mesh->confbase, strerror(errno));
@@ -901,23 +903,10 @@ static bool meshlink_setup(meshlink_handle_t *mesh) {
 		return false;
 	}
 
-	if(!main_config_lock(mesh)) {
-		logger(NULL, MESHLINK_ERROR, "Cannot lock main config file\n");
-		meshlink_errno = MESHLINK_ESTORAGE;
-		return false;
-	}
-
 	return true;
 }
 
 static bool meshlink_read_config(meshlink_handle_t *mesh) {
-	// Open the configuration file and lock it
-	if(!main_config_lock(mesh)) {
-		logger(NULL, MESHLINK_ERROR, "Cannot lock main config file\n");
-		meshlink_errno = MESHLINK_ESTORAGE;
-		return false;
-	}
-
 	config_t config;
 
 	if(!main_config_read(mesh, "current", &config, mesh->config_key)) {
@@ -967,6 +956,7 @@ static bool meshlink_read_config(meshlink_handle_t *mesh) {
 	mesh->self = new_node();
 	mesh->self->name = xstrdup(name);
 	mesh->self->devclass = mesh->devclass;
+	mesh->self->session_id = mesh->session_id;
 
 	if(!node_read_public_key(mesh, mesh->self)) {
 		logger(NULL, MESHLINK_ERROR, "Could not read our host configuration file!");
@@ -1101,14 +1091,11 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 
 	devtool_keyrotate_probe(1);
 
-	main_config_unlock(mesh);
-
 	// Rename confbase/current/ to confbase/old
 
 	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;
-		main_config_lock(mesh);
 		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
@@ -1120,18 +1107,12 @@ 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;
-		main_config_lock(mesh);
 		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
 	devtool_keyrotate_probe(3);
 
-	if(!main_config_lock(mesh)) {
-		pthread_mutex_unlock(&mesh->mutex);
-		return false;
-	}
-
 	// Cleanup the "old" confbase sub-directory
 
 	if(!config_destroy(mesh->confbase, "old")) {
@@ -1288,6 +1269,10 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 
 	randomize(&mesh->prng_state, sizeof(mesh->prng_state));
 
+	do {
+		randomize(&mesh->session_id, sizeof(mesh->session_id));
+	} while(mesh->session_id == 0);
+
 	memcpy(mesh->dev_class_traits, default_class_traits, sizeof(default_class_traits));
 
 	if(usingname) {
@@ -1318,6 +1303,12 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 
 	meshlink_queue_init(&mesh->outpacketqueue);
 
+	// Atomically lock the configuration directory.
+	if(!main_config_lock(mesh)) {
+		meshlink_close(mesh);
+		return NULL;
+	}
+
 	// If no configuration exists yet, create it.
 
 	if(!meshlink_confbase_exists(mesh)) {
@@ -1370,7 +1361,11 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 	}
 
 	add_local_addresses(mesh);
-	node_write_config(mesh, mesh->self);
+
+	if(!node_write_config(mesh, mesh->self)) {
+		logger(NULL, MESHLINK_ERROR, "Cannot update configuration\n");
+		return NULL;
+	}
 
 	idle_set(&mesh->loop, idle, mesh);
 
@@ -1559,12 +1554,11 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 
 	exit_outgoings(mesh);
 
-	// Write out any changed node config files
+	// Try to write out any changed node config files, ignore errors at this point.
 	if(mesh->nodes) {
 		for splay_each(node_t, n, mesh->nodes) {
 			if(n->status.dirty) {
-				node_write_config(mesh, n);
-				n->status.dirty = false;
+				n->status.dirty = !node_write_config(mesh, n);
 			}
 		}
 	}
@@ -1634,16 +1628,57 @@ bool meshlink_destroy(const char *confbase) {
 		return false;
 	}
 
-	if(!config_destroy(confbase, "current")) {
-		logger(NULL, MESHLINK_ERROR, "Cannot remove confbase sub-directories %s: %s\n", confbase, strerror(errno));
+	/* Exit early if the confbase directory itself doesn't exist */
+	if(access(confbase, F_OK) && errno == ENOENT) {
+		return true;
+	}
+
+	/* Take the lock the same way meshlink_open() would. */
+	char lockfilename[PATH_MAX];
+	snprintf(lockfilename, sizeof(lockfilename), "%s" SLASH "meshlink.lock", confbase);
+
+	FILE *lockfile = fopen(lockfilename, "w+");
+
+	if(!lockfile) {
+		logger(NULL, MESHLINK_ERROR, "Could not open lock file %s: %s", lockfilename, strerror(errno));
+		meshlink_errno = MESHLINK_ESTORAGE;
+		return false;
+	}
+
+#ifdef FD_CLOEXEC
+	fcntl(fileno(lockfile), F_SETFD, FD_CLOEXEC);
+#endif
+
+#ifdef HAVE_MINGW
+	// TODO: use _locking()?
+#else
+
+	if(flock(fileno(lockfile), LOCK_EX | LOCK_NB) != 0) {
+		logger(NULL, MESHLINK_ERROR, "Configuration directory %s still in use\n", lockfilename);
+		fclose(lockfile);
+		meshlink_errno = MESHLINK_EBUSY;
+		return false;
+	}
+
+#endif
+
+	if(!config_destroy(confbase, "current") || !config_destroy(confbase, "new") || !config_destroy(confbase, "old")) {
+		logger(NULL, MESHLINK_ERROR, "Cannot remove sub-directories in %s: %s\n", confbase, strerror(errno));
+		return false;
+	}
+
+	if(unlink(lockfilename)) {
+		logger(NULL, MESHLINK_ERROR, "Cannot remove lock file %s: %s\n", lockfilename, strerror(errno));
+		fclose(lockfile);
+		meshlink_errno = MESHLINK_ESTORAGE;
 		return false;
 	}
 
-	config_destroy(confbase, "new");
-	config_destroy(confbase, "old");
+	fclose(lockfile);
 
-	if(rmdir(confbase) && errno != ENOENT) {
-		logger(NULL, MESHLINK_ERROR, "Cannot remove directory %s: %s\n", confbase, strerror(errno));
+	/* TODO: do we need to remove confbase? Potential race condition? */
+	if(!sync_path(confbase)) {
+		logger(NULL, MESHLINK_ERROR, "Cannot sync directory %s: %s\n", confbase, strerror(errno));
 		meshlink_errno = MESHLINK_ESTORAGE;
 		return false;
 	}
@@ -1751,6 +1786,7 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 
 	if(n->status.blacklisted) {
 		logger(mesh, MESHLINK_ERROR, "Node %s blacklisted, dropping packet\n", n->name);
+		meshlink_errno = MESHLINK_EBLACKLISTED;
 		return false;
 	}
 
@@ -2136,11 +2172,15 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
 	node_t *n = (node_t *)node;
 	free(n->canonical_address);
 	n->canonical_address = canonical_address;
-	node_write_config(mesh, n);
+
+	if(!node_write_config(mesh, n)) {
+		pthread_mutex_unlock(&mesh->mutex);
+		return false;
+	}
 
 	pthread_mutex_unlock(&mesh->mutex);
 
-	return true;
+	return config_sync(mesh, "current");
 }
 
 bool meshlink_add_address(meshlink_handle_t *mesh, const char *address) {
@@ -2221,6 +2261,7 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 	mesh->self = new_node();
 	mesh->self->name = xstrdup(mesh->name);
 	mesh->self->devclass = mesh->devclass;
+	mesh->self->session_id = mesh->session_id;
 	xasprintf(&mesh->myport, "%d", port);
 
 	if(!node_read_public_key(mesh, mesh->self)) {
@@ -2771,7 +2812,11 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 			break;
 		}
 
-		config_write(mesh, "current", n->name, &config, mesh->config_key);
+		if(!config_write(mesh, "current", n->name, &config, mesh->config_key)) {
+			free_node(n);
+			return false;
+		}
+
 		node_add(mesh, n);
 	}
 
@@ -2792,10 +2837,10 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 	return true;
 }
 
-void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
+bool meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	if(!mesh || !node) {
 		meshlink_errno = MESHLINK_EINVAL;
-		return;
+		return false;
 	}
 
 	pthread_mutex_lock(&mesh->mutex);
@@ -2807,25 +2852,23 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		logger(mesh, MESHLINK_ERROR, "%s blacklisting itself?\n", node->name);
 		meshlink_errno = MESHLINK_EINVAL;
 		pthread_mutex_unlock(&mesh->mutex);
-		return;
+		return false;
 	}
 
 	if(n->status.blacklisted) {
 		logger(mesh, MESHLINK_DEBUG, "Node %s already blacklisted\n", node->name);
 		pthread_mutex_unlock(&mesh->mutex);
-		return;
+		return true;
 	}
 
 	n->status.blacklisted = true;
-	node_write_config(mesh, n);
-	config_sync(mesh, "current");
-
-	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", node->name);
 
-	//Immediately terminate any connections we have with the blacklisted node
+	/* Immediately shut down any connections we have with the blacklisted node.
+	 * We can't call terminate_connection(), because we might be called from a callback function.
+	 */
 	for list_each(connection_t, c, mesh->connections) {
 		if(c->node == n) {
-			terminate_connection(mesh, c, c->status.active);
+			shutdown(c->socket, SHUT_RDWR);
 		}
 	}
 
@@ -2837,40 +2880,57 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	n->mtuprobes = 0;
 	n->status.udp_confirmed = false;
 
-	if(n->status.reachable) {
-		update_node_status(mesh, n);
+	if(!node_write_config(mesh, n)) {
+		pthread_mutex_unlock(&mesh->mutex);
+		return false;
 	}
 
+	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", node->name);
+
 	pthread_mutex_unlock(&mesh->mutex);
+
+	return config_sync(mesh, "current");
 }
 
-void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
+bool meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	if(!mesh || !node) {
 		meshlink_errno = MESHLINK_EINVAL;
-		return;
+		return false;
 	}
 
 	pthread_mutex_lock(&mesh->mutex);
 
 	node_t *n = (node_t *)node;
 
+	if(n == mesh->self) {
+		logger(mesh, MESHLINK_ERROR, "%s whitelisting itself?\n", node->name);
+		meshlink_errno = MESHLINK_EINVAL;
+		pthread_mutex_unlock(&mesh->mutex);
+		return false;
+	}
+
 	if(!n->status.blacklisted) {
 		logger(mesh, MESHLINK_DEBUG, "Node %s was already whitelisted\n", node->name);
-		meshlink_errno = MESHLINK_EINVAL;
 		pthread_mutex_unlock(&mesh->mutex);
-		return;
+		return true;
 	}
 
 	n->status.blacklisted = false;
-	node_write_config(mesh, n);
-	config_sync(mesh, "current");
 
 	if(n->status.reachable) {
 		update_node_status(mesh, n);
 	}
 
+	if(!node_write_config(mesh, n)) {
+		pthread_mutex_unlock(&mesh->mutex);
+		return false;
+	}
+
+	logger(mesh, MESHLINK_DEBUG, "Whitelisted %s.\n", node->name);
+
 	pthread_mutex_unlock(&mesh->mutex);
-	return;
+
+	return config_sync(mesh, "current");
 }
 
 void meshlink_set_default_blacklist(meshlink_handle_t *mesh, bool blacklist) {
@@ -2891,7 +2951,10 @@ void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const
 	node_t *n = (node_t *)node;
 	memmove(n->recent + 1, n->recent, 4 * sizeof(*n->recent));
 	memcpy(n->recent, addr, SALEN(*addr));
-	node_write_config(mesh, n);
+
+	if(!node_write_config(mesh, n)) {
+		logger(mesh, MESHLINK_DEBUG, "Could not update %s\n", n->name);
+	}
 
 	pthread_mutex_unlock(&mesh->mutex);
 	// @TODO do we want to fire off a connection attempt right away?
@@ -3150,7 +3213,7 @@ void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *ch
 }
 
 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(data || len) {
+	if(data && len) {
 		abort();        // TODO: handle non-NULL data
 	}
 
@@ -3176,6 +3239,7 @@ 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);
 		return NULL;
 	}
@@ -3183,6 +3247,11 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 	meshlink_channel_t *channel = xzalloc(sizeof(*channel));
 	channel->node = n;
 	channel->receive_cb = cb;
+
+	if(data && !len) {
+		channel->priv = (void *)data;
+	}
+
 	channel->c = utcp_connect_ex(n->utcp, port, channel_recv, channel, flags);
 
 	pthread_mutex_unlock(&mesh->mutex);