X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fmeshlink.c;h=e6aea4dd3f708a644e482ee8de504414fd4c3e1d;hb=6c897377f68fc23ca9a8b23a6ca204517998b2e9;hp=f1b6a334c6a7bb90bd6be8018a90b861a65a2842;hpb=b0319f8d358c476e29d3c6daeef1cda616cfd447;p=meshlink

diff --git a/src/meshlink.c b/src/meshlink.c
index f1b6a334..e6aea4dd 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)) {
@@ -1634,16 +1625,57 @@ 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;
 	}
 
-	config_destroy(confbase, "new");
-	config_destroy(confbase, "old");
+#ifdef FD_CLOEXEC
+	fcntl(fileno(lockfile), F_SETFD, FD_CLOEXEC);
+#endif
 
-	if(rmdir(confbase) && errno != ENOENT) {
-		logger(NULL, MESHLINK_ERROR, "Cannot remove directory %s: %s\n", confbase, strerror(errno));
+#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;
+	}
+
+	fclose(lockfile);
+
+	/* 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 +1783,7 @@ 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;
 	}
 
@@ -2221,6 +2254,7 @@ 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)) {
@@ -2822,10 +2856,12 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 
 	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);
 		}
 	}
 
@@ -2837,10 +2873,6 @@ 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);
-	}
-
 	pthread_mutex_unlock(&mesh->mutex);
 }
 
@@ -2854,9 +2886,15 @@ void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 
 	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;
+	}
+
 	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;
 	}
@@ -2869,6 +2907,8 @@ void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		update_node_status(mesh, n);
 	}
 
+	logger(mesh, MESHLINK_DEBUG, "Whitelisted %s.\n", node->name);
+
 	pthread_mutex_unlock(&mesh->mutex);
 	return;
 }
@@ -3176,6 +3216,7 @@ 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;
 	}