X-Git-Url: http://git.meshlink.io/?p=meshlink;a=blobdiff_plain;f=src%2Fmeshlink.c;h=54187a59ed9673a63b166eab73b88b44dbce85bd;hp=6df7c419261fc30f175ef016d00538c295d77f29;hb=a5a8005b2d89712e124ab7295165a3e229abdad5;hpb=92283d7342fabd882126a892b2636d57ff0458de

diff --git a/src/meshlink.c b/src/meshlink.c
index 6df7c419..54187a59 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -16,17 +16,6 @@
     with this program; if not, write to the Free Software Foundation, Inc.,
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
-#define VAR_SERVER 1    /* Should be in meshlink.conf */
-#define VAR_HOST 2      /* Can be in host config file */
-#define VAR_MULTIPLE 4  /* Multiple statements allowed */
-#define VAR_OBSOLETE 8  /* Should not be used anymore */
-#define VAR_SAFE 16     /* Variable is safe when accepting invitations */
-#define MAX_ADDRESS_LENGTH 45 /* Max length of an (IPv6) address */
-#define MAX_PORT_LENGTH 5 /* 0-65535 */
-typedef struct {
-	const char *name;
-	int type;
-} var_t;
 
 #include "system.h"
 #include <pthread.h>
@@ -37,6 +26,9 @@ typedef struct {
 #include "meshlink_internal.h"
 #include "netutl.h"
 #include "node.h"
+#include "submesh.h"
+#include "packmsg.h"
+#include "prf.h"
 #include "protocol.h"
 #include "route.h"
 #include "sockaddr.h"
@@ -44,46 +36,16 @@ typedef struct {
 #include "xalloc.h"
 #include "ed25519/sha512.h"
 #include "discovery.h"
+#include "devtools.h"
 
 #ifndef MSG_NOSIGNAL
 #define MSG_NOSIGNAL 0
 #endif
-
 __thread meshlink_errno_t meshlink_errno;
 meshlink_log_cb_t global_log_cb;
 meshlink_log_level_t global_log_level;
 
-//TODO: this can go away completely
-const var_t variables[] = {
-	/* Server configuration */
-	{"ConnectTo", VAR_SERVER | VAR_MULTIPLE | VAR_SAFE},
-	{"Name", VAR_SERVER},
-	/* Host configuration */
-	{"CanonicalAddress", VAR_HOST},
-	{"Address", VAR_HOST | VAR_MULTIPLE},
-	{"ECDSAPublicKey", VAR_HOST},
-	{"Port", VAR_HOST},
-	{NULL, 0}
-};
-
-static bool fcopy(FILE *out, const char *filename) {
-	FILE *in = fopen(filename, "r");
-
-	if(!in) {
-		logger(NULL, MESHLINK_ERROR, "Could not open %s: %s\n", filename, strerror(errno));
-		return false;
-	}
-
-	char buf[1024];
-	size_t len;
-
-	while((len = fread(buf, 1, sizeof(buf), in))) {
-		fwrite(buf, len, 1, out);
-	}
-
-	fclose(in);
-	return true;
-}
+typedef bool (*search_node_by_condition_t)(const node_t *, const void *);
 
 static int rstrip(char *value) {
 	int len = strlen(value);
@@ -95,80 +57,18 @@ static int rstrip(char *value) {
 	return len;
 }
 
-static void scan_for_hostname(const char *filename, char **hostname, char **port) {
-	char line[4096];
-	bool canonical = false;
-
-	if(!filename || (*hostname && *port)) {
-		return;
-	}
-
-	FILE *f = fopen(filename, "r");
-
-	if(!f) {
+static void get_canonical_address(node_t *n, char **hostname, char **port) {
+	if(!n->canonical_address) {
 		return;
 	}
 
-	while(fgets(line, sizeof(line), f)) {
-		if(!rstrip(line)) {
-			continue;
-		}
-
-		char *p = line, *q;
-		p += strcspn(p, "\t =");
-
-		if(!*p) {
-			continue;
-		}
-
-		q = p + strspn(p, "\t ");
-
-		if(*q == '=') {
-			q += 1 + strspn(q + 1, "\t ");
-		}
-
-		// q is now pointing to the hostname
-		*p = 0;
-		p = q + strcspn(q, "\t ");
-
-		if(*p) {
-			*p++ = 0;
-		}
-
-		p += strspn(p, "\t ");
-		p[strcspn(p, "\t ")] = 0;
-		// p is now pointing to the port, if present
-
-		if(!*port && !strcasecmp(line, "Port")) {
-			*port = xstrdup(q);
-		} else if(!canonical && !*hostname && !strcasecmp(line, "Address")) {
-			// Check that the hostname is a symbolic name (it's not a numeric IPv4 or IPv6 address)
-			if(!q[strspn(q, "0123456789.")] || strchr(q, ':')) {
-				continue;
-			}
-
-			*hostname = xstrdup(q);
-
-			if(*p) {
-				free(*port);
-				*port = xstrdup(p);
-			}
-		} else if(!strcasecmp(line, "CanonicalAddress")) {
-			*hostname = xstrdup(q);
-			canonical = true;
-
-			if(*p) {
-				free(*port);
-				*port = xstrdup(p);
-			}
-		}
+	*hostname = xstrdup(n->canonical_address);
+	char *space = strchr(*hostname, ' ');
 
-		if(canonical && *hostname && *port) {
-			break;
-		}
+	if(space) {
+		*space++ = 0;
+		*port = xstrdup(space);
 	}
-
-	fclose(f);
 }
 
 static bool is_valid_hostname(const char *hostname) {
@@ -217,10 +117,54 @@ static void set_timeout(int sock, int timeout) {
 	setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
 }
 
+struct socket_in_netns_params {
+	int domain;
+	int type;
+	int protocol;
+	int netns;
+	int fd;
+};
+
+#ifdef HAVE_SETNS
+static void *socket_in_netns_thread(void *arg) {
+	struct socket_in_netns_params *params = arg;
+
+	if(setns(params->netns, CLONE_NEWNET) == -1) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	params->fd = socket(params->domain, params->type, params->protocol);
+
+	return NULL;
+}
+#endif // HAVE_SETNS
+
+static int socket_in_netns(int domain, int type, int protocol, int netns) {
+	if(netns == -1) {
+		return socket(domain, type, protocol);
+	}
+
+#ifdef HAVE_SETNS
+	struct socket_in_netns_params params = {domain, type, protocol, netns, -1};
+
+	pthread_t thr;
+
+	if(pthread_create(&thr, NULL, socket_in_netns_thread, &params) == 0) {
+		pthread_join(thr, NULL);
+	}
+
+	return params.fd;
+#else
+	return -1;
+#endif // HAVE_SETNS
+
+}
+
 // 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) {
+static bool getlocaladdr(char *destaddr, struct sockaddr *sn, socklen_t *sl, int netns) {
 	struct addrinfo *rai = NULL;
 	const struct addrinfo hint = {
 		.ai_family = AF_UNSPEC,
@@ -232,7 +176,7 @@ static bool getlocaladdrname(char *destaddr, char *host, socklen_t hostlen) {
 		return false;
 	}
 
-	int sock = socket(rai->ai_family, rai->ai_socktype, rai->ai_protocol);
+	int sock = socket_in_netns(rai->ai_family, rai->ai_socktype, rai->ai_protocol, netns);
 
 	if(sock == -1) {
 		freeaddrinfo(rai);
@@ -240,16 +184,27 @@ static bool getlocaladdrname(char *destaddr, char *host, socklen_t hostlen) {
 	}
 
 	if(connect(sock, rai->ai_addr, rai->ai_addrlen) && !sockwouldblock(errno)) {
+		closesocket(sock);
 		freeaddrinfo(rai);
 		return false;
 	}
 
 	freeaddrinfo(rai);
 
+	if(getsockname(sock, sn, sl)) {
+		closesocket(sock);
+		return false;
+	}
+
+	closesocket(sock);
+	return true;
+}
+
+static bool getlocaladdrname(char *destaddr, char *host, socklen_t hostlen, int netns) {
 	struct sockaddr_storage sn;
 	socklen_t sl = sizeof(sn);
 
-	if(getsockname(sock, (struct sockaddr *)&sn, &sl)) {
+	if(!getlocaladdr(destaddr, (struct sockaddr *)&sn, &sl, netns)) {
 		return false;
 	}
 
@@ -277,7 +232,7 @@ char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int fami
 			continue;
 		}
 
-		int s = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol);
+		int s = socket_in_netns(aip->ai_family, aip->ai_socktype, aip->ai_protocol, mesh->netns);
 
 		if(s >= 0) {
 			set_timeout(s, 5000);
@@ -324,22 +279,6 @@ char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int fami
 		hostname = NULL;
 	}
 
-	// If there is no hostname, determine the address used for an outgoing connection.
-	if(!hostname) {
-		char localaddr[NI_MAXHOST];
-		bool success = false;
-
-		if(family == AF_INET) {
-			success = getlocaladdrname("93.184.216.34", localaddr, sizeof(localaddr));
-		} else if(family == AF_INET6) {
-			success = getlocaladdrname("2606:2800:220:1:248:1893:25c8:1946", localaddr, sizeof(localaddr));
-		}
-
-		if(success) {
-			hostname = xstrdup(localaddr);
-		}
-	}
-
 	if(!hostname) {
 		meshlink_errno = MESHLINK_ERESOLV;
 	}
@@ -347,125 +286,194 @@ char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int fami
 	return hostname;
 }
 
-// String comparison which handles NULL arguments
-static bool safe_streq(const char *a, const char *b) {
-	if (!a || !b)
-		return a == b;
-	else
-		return !strcmp(a, b);
-}
+char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int family) {
+	(void)mesh;
 
-// This gets the hostname part for use in invitation URLs
-static char *get_my_hostname(meshlink_handle_t *mesh) {
-	char *hostname[3] = {NULL};
-	char *port[3] = {NULL};
-	char *hostport = NULL;
+	// Determine address of the local interface used for outgoing connections.
+	char localaddr[NI_MAXHOST];
+	bool success = false;
 
-	// Use the best Address statement in our own host config file
-	char filename[PATH_MAX] = "";
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
-	scan_for_hostname(filename, &hostname[0], &port[0]);
+	if(family == AF_INET) {
+		success = getlocaladdrname("93.184.216.34", localaddr, sizeof(localaddr), mesh->netns);
+	} else if(family == AF_INET6) {
+		success = getlocaladdrname("2606:2800:220:1:248:1893:25c8:1946", localaddr, sizeof(localaddr), mesh->netns);
+	}
 
-	hostname[1] = meshlink_get_external_address_for_family(mesh, AF_INET);
-	hostname[2] = meshlink_get_external_address_for_family(mesh, AF_INET6);
+	if(!success) {
+		meshlink_errno = MESHLINK_ENETWORK;
+		return NULL;
+	}
 
-	// Concatenate all unique address to the hostport string
-	for (int i = 0; i < 3; i++) {
-		if (!hostname[i])
+	return xstrdup(localaddr);
+}
+
+void remove_duplicate_hostnames(char *host[], char *port[], int n) {
+	for(int i = 0; i < n; i++) {
+		if(!host[i]) {
 			continue;
+		}
 
 		// Ignore duplicate hostnames
 		bool found = false;
 
-		for (int j = 0; i < j; j++) {
-			if (safe_streq(hostname[i], hostname[j]) && safe_streq(port[i], port[j])) {
-				found = true;
-				break;
+		for(int j = 0; j < i; j++) {
+			if(!host[j]) {
+				continue;
+			}
+
+			if(strcmp(host[i], host[j])) {
+				continue;
+			}
+
+			if(strcmp(port[i], port[j])) {
+				continue;
 			}
+
+			found = true;
+			break;
 		}
 
-		if (found) {
-			free(hostname[i]);
+		if(found || !is_valid_hostname(host[i])) {
+			free(host[i]);
 			free(port[i]);
-			hostname[i] = NULL;
+			host[i] = NULL;
 			port[i] = NULL;
 			continue;
 		}
+	}
+}
 
-		// Ensure we have the same addresses in our own host config file.
-		char *tmphostport;
-		xasprintf(&tmphostport, "%s %s", hostname[i], port[i] ? port[i] : mesh->myport);
-		append_config_file(mesh, mesh->self->name, "Address", tmphostport);
-		free(tmphostport);
+// This gets the hostname part for use in invitation URLs
+static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
+	char *hostname[4] = {NULL};
+	char *port[4] = {NULL};
+	char *hostport = NULL;
 
-		// Append the address to the hostport string
-		char *newhostport;
-		xasprintf(&newhostport, (strchr(hostname[i], ':') ? "%s%s[%s]:%s" : "%s%s%s:%s"), hostport ? hostport : "", hostport ? "," : "", hostname[i], port[i] ? port[i] : mesh->myport);
-		free(hostname[i]);
-		free(port[i]);
-		free(hostport);
-		hostport = newhostport;
+	if(!(flags & (MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC))) {
+		flags |= MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC;
 	}
 
-	return hostport;
-}
-
-static char *get_line(const char **data) {
-	if(!data || !*data) {
-		return NULL;
+	if(!(flags & (MESHLINK_INVITE_IPV4 | MESHLINK_INVITE_IPV6))) {
+		flags |= MESHLINK_INVITE_IPV4 | MESHLINK_INVITE_IPV6;
 	}
 
-	if(! **data) {
-		*data = NULL;
-		return NULL;
+	// Add local addresses if requested
+	if(flags & MESHLINK_INVITE_LOCAL) {
+		if(flags & MESHLINK_INVITE_IPV4) {
+			hostname[0] = meshlink_get_local_address_for_family(mesh, AF_INET);
+		}
+
+		if(flags & MESHLINK_INVITE_IPV6) {
+			hostname[1] = meshlink_get_local_address_for_family(mesh, AF_INET6);
+		}
 	}
 
-	static char line[1024];
-	const char *end = strchr(*data, '\n');
-	size_t len = end ? (size_t)(end - *data) : strlen(*data);
+	// Add public/canonical addresses if requested
+	if(flags & MESHLINK_INVITE_PUBLIC) {
+		// Try the CanonicalAddress first
+		get_canonical_address(mesh->self, &hostname[2], &port[2]);
 
-	if(len >= sizeof(line)) {
-		logger(NULL, MESHLINK_ERROR, "Maximum line length exceeded!\n");
-		return NULL;
+		if(!hostname[2]) {
+			if(flags & MESHLINK_INVITE_IPV4) {
+				hostname[2] = meshlink_get_external_address_for_family(mesh, AF_INET);
+			}
+
+			if(flags & MESHLINK_INVITE_IPV6) {
+				hostname[3] = meshlink_get_external_address_for_family(mesh, AF_INET6);
+			}
+		}
 	}
 
-	if(len && !isprint(**data)) {
-		abort();
+	for(int i = 0; i < 4; i++) {
+		// Ensure we always have a port number
+		if(hostname[i] && !port[i]) {
+			port[i] = xstrdup(mesh->myport);
+		}
 	}
 
-	memcpy(line, *data, len);
-	line[len] = 0;
+	remove_duplicate_hostnames(hostname, port, 4);
 
-	if(end) {
-		*data = end + 1;
-	} else {
-		*data = NULL;
-	}
+	if(!(flags & MESHLINK_INVITE_NUMERIC)) {
+		for(int i = 0; i < 4; i++) {
+			if(!hostname[i]) {
+				continue;
+			}
 
-	return line;
-}
+			// Convert what we have to a sockaddr
+			struct addrinfo *ai_in, *ai_out;
+			struct addrinfo hint = {
+				.ai_family = AF_UNSPEC,
+				.ai_flags = AI_NUMERICSERV,
+				.ai_socktype = SOCK_STREAM,
+			};
+			int err = getaddrinfo(hostname[i], port[i], &hint, &ai_in);
+
+			if(err || !ai_in) {
+				continue;
+			}
 
-static char *get_value(const char *data, const char *var) {
-	char *line = get_line(&data);
+			// Convert it to a hostname
+			char resolved_host[NI_MAXHOST];
+			char resolved_port[NI_MAXSERV];
+			err = getnameinfo(ai_in->ai_addr, ai_in->ai_addrlen, resolved_host, sizeof resolved_host, resolved_port, sizeof resolved_port, NI_NUMERICSERV);
 
-	if(!line) {
-		return NULL;
-	}
+			if(err || !is_valid_hostname(resolved_host)) {
+				freeaddrinfo(ai_in);
+				continue;
+			}
+
+			// Convert the hostname back to a sockaddr
+			hint.ai_family = ai_in->ai_family;
+			err = getaddrinfo(resolved_host, resolved_port, &hint, &ai_out);
+
+			if(err || !ai_out) {
+				freeaddrinfo(ai_in);
+				continue;
+			}
+
+			// Check if it's still the same sockaddr
+			if(ai_in->ai_addrlen != ai_out->ai_addrlen || memcmp(ai_in->ai_addr, ai_out->ai_addr, ai_in->ai_addrlen)) {
+				freeaddrinfo(ai_in);
+				freeaddrinfo(ai_out);
+				continue;
+			}
 
-	char *sep = line + strcspn(line, " \t=");
-	char *val = sep + strspn(sep, " \t");
+			// Yes: replace the hostname with the resolved one
+			free(hostname[i]);
+			hostname[i] = xstrdup(resolved_host);
 
-	if(*val == '=') {
-		val += 1 + strspn(val + 1, " \t");
+			freeaddrinfo(ai_in);
+			freeaddrinfo(ai_out);
+		}
 	}
 
-	*sep = 0;
+	// Remove duplicates again, since IPv4 and IPv6 addresses might map to the same hostname
+	remove_duplicate_hostnames(hostname, port, 4);
 
-	if(strcasecmp(line, var)) {
-		return NULL;
+	// Concatenate all unique address to the hostport string
+	for(int i = 0; i < 4; i++) {
+		if(!hostname[i]) {
+			continue;
+		}
+
+		// Ensure we have the same addresses in our own host config file.
+		char *tmphostport;
+		xasprintf(&tmphostport, "%s %s", hostname[i], port[i]);
+		/// TODO: FIX
+		//config_add_string(&mesh->config, "Address", tmphostport);
+		free(tmphostport);
+
+		// Append the address to the hostport string
+		char *newhostport;
+		xasprintf(&newhostport, (strchr(hostname[i], ':') ? "%s%s[%s]:%s" : "%s%s%s:%s"), hostport ? hostport : "", hostport ? "," : "", hostname[i], port[i]);
+		free(hostport);
+		hostport = newhostport;
+
+		free(hostname[i]);
+		free(port[i]);
 	}
 
-	return val;
+	return hostport;
 }
 
 static bool try_bind(int port) {
@@ -484,46 +492,35 @@ static bool try_bind(int port) {
 		return false;
 	}
 
-	while(ai) {
-		int fd = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
+	//while(ai) {
+	for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
+		int fd = socket(aip->ai_family, SOCK_STREAM, IPPROTO_TCP);
 
 		if(!fd) {
 			freeaddrinfo(ai);
 			return false;
 		}
 
-		int result = bind(fd, ai->ai_addr, ai->ai_addrlen);
+		int result = bind(fd, aip->ai_addr, aip->ai_addrlen);
 		closesocket(fd);
 
 		if(result) {
 			freeaddrinfo(ai);
 			return false;
 		}
-
-		ai = ai->ai_next;
 	}
 
 	freeaddrinfo(ai);
 	return true;
 }
 
-int check_port(meshlink_handle_t *mesh) {
+static int check_port(meshlink_handle_t *mesh) {
 	for(int i = 0; i < 1000; i++) {
-		int port = 0x1000 + (rand() & 0x7fff);
+		int port = 0x1000 + prng(mesh, 0x8000);
 
 		if(try_bind(port)) {
-			char filename[PATH_MAX];
-			snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->name);
-			FILE *f = fopen(filename, "a");
-
-			if(!f) {
-				meshlink_errno = MESHLINK_ESTORAGE;
-				logger(mesh, MESHLINK_DEBUG, "Could not store Port.\n");
-				return 0;
-			}
-
-			fprintf(f, "Port = %d\n", port);
-			fclose(f);
+			free(mesh->myport);
+			xasprintf(&mesh->myport, "%d", port);
 			return port;
 		}
 	}
@@ -533,33 +530,53 @@ int check_port(meshlink_handle_t *mesh) {
 	return 0;
 }
 
-static void deltree(const char *dirname) {
-	DIR *d = opendir(dirname);
+static bool write_main_config_files(meshlink_handle_t *mesh) {
+	if(!mesh->confbase) {
+		return true;
+	}
 
-	if(d) {
-		struct dirent *ent;
+	uint8_t buf[4096];
 
-		while((ent = readdir(d))) {
-			if(ent->d_name[0] == '.') {
-				continue;
-			}
+	/* Write the main config file */
+	packmsg_output_t out = {buf, sizeof buf};
 
-			char filename[PATH_MAX];
-			snprintf(filename, sizeof(filename), "%s" SLASH "%s", dirname, ent->d_name);
+	packmsg_add_uint32(&out, MESHLINK_CONFIG_VERSION);
+	packmsg_add_str(&out, mesh->name);
+	packmsg_add_bin(&out, ecdsa_get_private_key(mesh->private_key), 96);
+	packmsg_add_bin(&out, ecdsa_get_private_key(mesh->invitation_key), 96);
+	packmsg_add_uint16(&out, atoi(mesh->myport));
 
-			if(unlink(filename)) {
-				deltree(filename);
-			}
-		}
+	if(!packmsg_output_ok(&out)) {
+		return false;
+	}
+
+	config_t config = {buf, packmsg_output_size(&out, buf)};
+
+	if(!main_config_write(mesh, "current", &config, mesh->config_key)) {
+		return false;
+	}
 
-		closedir(d);
+	/* Write our own host config file */
+	if(!node_write_config(mesh, mesh->self)) {
+		return false;
 	}
 
-	rmdir(dirname);
+	return true;
 }
 
-static bool finalize_join(meshlink_handle_t *mesh) {
-	char *name = xstrdup(get_value(mesh->data, "Name"));
+static bool finalize_join(meshlink_handle_t *mesh, const void *buf, uint16_t len) {
+	packmsg_input_t in = {buf, len};
+	uint32_t version = packmsg_get_uint32(&in);
+
+	if(version != MESHLINK_INVITATION_VERSION) {
+		logger(mesh, MESHLINK_ERROR, "Invalid invitation version!\n");
+		return false;
+	}
+
+	char *name = packmsg_get_str_dup(&in);
+	packmsg_skip_element(&in); /* submesh */
+	dev_class_t devclass = packmsg_get_int32(&in);
+	uint32_t count = packmsg_get_array(&in);
 
 	if(!name) {
 		logger(mesh, MESHLINK_DEBUG, "No Name found in invitation!\n");
@@ -568,176 +585,91 @@ static bool finalize_join(meshlink_handle_t *mesh) {
 
 	if(!check_id(name)) {
 		logger(mesh, MESHLINK_DEBUG, "Invalid Name found in invitation: %s!\n", name);
+		free(name);
 		return false;
 	}
 
-	char filename[PATH_MAX];
-	snprintf(filename, sizeof(filename), "%s" SLASH "meshlink.conf", mesh->confbase);
-
-	FILE *f = fopen(filename, "w");
-
-	if(!f) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create file %s: %s\n", filename, strerror(errno));
+	if(!count) {
+		logger(mesh, MESHLINK_ERROR, "Incomplete invitation file!\n");
+		free(name);
 		return false;
 	}
 
-	fprintf(f, "Name = %s\n", name);
-
-	// Wipe all old host config files and invitations
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts", mesh->confbase);
-	deltree(filename);
+	free(mesh->name);
+	free(mesh->self->name);
+	mesh->name = name;
+	mesh->self->name = xstrdup(name);
+	mesh->self->devclass = devclass == DEV_CLASS_UNKNOWN ? mesh->devclass : devclass;
 
-	if(mkdir(filename, 0777) && errno != EEXIST) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create directory %s: %s\n", filename, strerror(errno));
+	// Initialize configuration directory
+	if(!config_init(mesh, "current")) {
 		return false;
 	}
 
-	snprintf(filename, sizeof(filename), "%s" SLASH "invitations", mesh->confbase);
-	deltree(filename);
-
-	// Create a new host config file for ourself
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
-	FILE *fh = fopen(filename, "w");
-
-	if(!fh) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create file %s: %s\n", filename, strerror(errno));
-		fclose(f);
+	if(!write_main_config_files(mesh)) {
 		return false;
 	}
 
-	// Filter first chunk on approved keywords, split between meshlink.conf and hosts/Name
-	// Other chunks go unfiltered to their respective host config files
-	const char *p = mesh->data;
-	char *l, *value;
-
-	while((l = get_line(&p))) {
-		// Ignore comments
-		if(*l == '#') {
-			continue;
-		}
-
-		// Split line into variable and value
-		int len = strcspn(l, "\t =");
-		value = l + len;
-		value += strspn(value, "\t ");
-
-		if(*value == '=') {
-			value++;
-			value += strspn(value, "\t ");
-		}
-
-		l[len] = 0;
+	// Write host config files
+	while(count--) {
+		const void *data;
+		uint32_t len = packmsg_get_bin_raw(&in, &data);
 
-		// Is it a Name?
-		if(!strcasecmp(l, "Name"))
-			if(strcmp(value, name)) {
-				break;
-			} else {
-				continue;
-			} else if(!strcasecmp(l, "NetName")) {
-			continue;
+		if(!len) {
+			logger(mesh, MESHLINK_ERROR, "Incomplete invitation file!\n");
+			return false;
 		}
 
-		// Check the list of known variables
-		bool found = false;
-		int i;
-
-		for(i = 0; variables[i].name; i++) {
-			if(strcasecmp(l, variables[i].name)) {
-				continue;
-			}
+		packmsg_input_t in2 = {data, len};
+		uint32_t version = packmsg_get_uint32(&in2);
+		char *name = packmsg_get_str_dup(&in2);
 
-			found = true;
+		if(!packmsg_input_ok(&in2) || version != MESHLINK_CONFIG_VERSION || !check_id(name)) {
+			free(name);
+			packmsg_input_invalidate(&in);
 			break;
 		}
 
-		// Ignore unknown and unsafe variables
-		if(!found) {
-			logger(mesh, MESHLINK_DEBUG, "Ignoring unknown variable '%s' in invitation.\n", l);
-			continue;
-		} else if(!(variables[i].type & VAR_SAFE)) {
-			logger(mesh, MESHLINK_DEBUG, "Ignoring unsafe variable '%s' in invitation.\n", l);
-			continue;
-		}
-
-		// Copy the safe variable to the right config file
-		fprintf(variables[i].type & VAR_HOST ? fh : f, "%s = %s\n", l, value);
-	}
-
-	fclose(f);
-
-	while(l && !strcasecmp(l, "Name")) {
-		if(!check_id(value)) {
-			logger(mesh, MESHLINK_DEBUG, "Invalid Name found in invitation.\n");
-			return false;
+		if(!check_id(name)) {
+			free(name);
+			break;
 		}
 
-		if(!strcmp(value, name)) {
+		if(!strcmp(name, mesh->name)) {
 			logger(mesh, MESHLINK_DEBUG, "Secondary chunk would overwrite our own host config file.\n");
+			free(name);
+			meshlink_errno = MESHLINK_EPEER;
 			return false;
 		}
 
-		snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, value);
-		f = fopen(filename, "w");
+		node_t *n = new_node();
+		n->name = name;
+
+		config_t config = {data, len};
 
-		if(!f) {
-			logger(mesh, MESHLINK_DEBUG, "Could not create file %s: %s\n", filename, strerror(errno));
+		if(!node_read_from_config(mesh, n, &config)) {
+			free_node(n);
+			logger(mesh, MESHLINK_ERROR, "Invalid host config file in invitation file!\n");
+			meshlink_errno = MESHLINK_EPEER;
 			return false;
 		}
 
-		while((l = get_line(&p))) {
-			if(!strcmp(l, "#---------------------------------------------------------------#")) {
-				continue;
-			}
-
-			int len = strcspn(l, "\t =");
+		node_add(mesh, n);
 
-			if(len == 4 && !strncasecmp(l, "Name", 4)) {
-				value = l + len;
-				value += strspn(value, "\t ");
-
-				if(*value == '=') {
-					value++;
-					value += strspn(value, "\t ");
-				}
-
-				l[len] = 0;
-				break;
-			}
-
-			fputs(l, f);
-			fputc('\n', f);
+		if(!config_write(mesh, "current", n->name, &config, mesh->config_key)) {
+			return false;
 		}
-
-		fclose(f);
 	}
 
-	char *b64key = ecdsa_get_base64_public_key(mesh->self->connection->ecdsa);
-
-	if(!b64key) {
-		fclose(fh);
+	/* Ensure the configuration directory metadata is on disk */
+	if(!config_sync(mesh, "current")) {
 		return false;
 	}
 
-	fprintf(fh, "ECDSAPublicKey = %s\n", b64key);
-	fprintf(fh, "Port = %s\n", mesh->myport);
-
-	fclose(fh);
-
-	sptps_send_record(&(mesh->sptps), 1, b64key, strlen(b64key));
-	free(b64key);
-
-	free(mesh->name);
-	free(mesh->self->name);
-	free(mesh->self->connection->name);
-	mesh->name = xstrdup(name);
-	mesh->self->name = xstrdup(name);
-	mesh->self->connection->name = name;
+	sptps_send_record(&(mesh->sptps), 1, ecdsa_get_public_key(mesh->private_key), 32);
 
 	logger(mesh, MESHLINK_DEBUG, "Configuration stored in: %s\n", mesh->confbase);
 
-	load_all_nodes(mesh);
-
 	return true;
 }
 
@@ -770,17 +702,9 @@ static bool invitation_receive(void *handle, uint8_t type, const void *msg, uint
 		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;
+		return finalize_join(mesh, msg, len);
 
 	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;
@@ -825,8 +749,9 @@ static bool recvline(meshlink_handle_t *mesh, size_t len) {
 
 	return true;
 }
+
 static bool sendline(int fd, char *format, ...) {
-	static char buffer[4096];
+	char buffer[4096];
 	char *p = buffer;
 	int blen = 0;
 	va_list ap;
@@ -882,61 +807,18 @@ const char *meshlink_strerror(meshlink_errno_t err) {
 }
 
 static bool ecdsa_keygen(meshlink_handle_t *mesh) {
-	ecdsa_t *key;
-	FILE *f;
-	char pubname[PATH_MAX], privname[PATH_MAX];
+	logger(mesh, MESHLINK_DEBUG, "Generating ECDSA keypairs:\n");
 
-	logger(mesh, MESHLINK_DEBUG, "Generating ECDSA keypair:\n");
+	mesh->private_key = ecdsa_generate();
+	mesh->invitation_key = ecdsa_generate();
 
-	if(!(key = ecdsa_generate())) {
+	if(!mesh->private_key || !mesh->invitation_key) {
 		logger(mesh, MESHLINK_DEBUG, "Error during key generation!\n");
 		meshlink_errno = MESHLINK_EINTERNAL;
 		return false;
-	} else {
-		logger(mesh, MESHLINK_DEBUG, "Done.\n");
 	}
 
-	if(snprintf(privname, sizeof(privname), "%s" SLASH "ecdsa_key.priv", mesh->confbase) >= PATH_MAX) {
-		logger(mesh, MESHLINK_DEBUG, "Filename too long: %s" SLASH "ecdsa_key.priv\n", mesh->confbase);
-		meshlink_errno = MESHLINK_ESTORAGE;
-		return false;
-	}
-
-	f = fopen(privname, "wb");
-
-	if(!f) {
-		meshlink_errno = MESHLINK_ESTORAGE;
-		return false;
-	}
-
-#ifdef HAVE_FCHMOD
-	fchmod(fileno(f), 0600);
-#endif
-
-	if(!ecdsa_write_pem_private_key(key, f)) {
-		logger(mesh, MESHLINK_DEBUG, "Error writing private key!\n");
-		ecdsa_free(key);
-		fclose(f);
-		meshlink_errno = MESHLINK_EINTERNAL;
-		return false;
-	}
-
-	fclose(f);
-
-	snprintf(pubname, sizeof(pubname), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->name);
-	f = fopen(pubname, "a");
-
-	if(!f) {
-		meshlink_errno = MESHLINK_ESTORAGE;
-		return false;
-	}
-
-	char *pubkey = ecdsa_get_base64_public_key(key);
-	fprintf(f, "ECDSAPublicKey = %s\n", pubkey);
-	free(pubkey);
-
-	fclose(f);
-	ecdsa_free(key);
+	logger(mesh, MESHLINK_DEBUG, "Done.\n");
 
 	return true;
 }
@@ -963,80 +845,155 @@ static struct timeval idle(event_loop_t *loop, void *data) {
 
 // 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];
+	struct sockaddr_storage sn;
+	sn.ss_family = AF_UNKNOWN;
+	socklen_t sl = sizeof(sn);
 
 	// 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);
+	if(getlocaladdr("93.184.216.34", (struct sockaddr *)&sn, &sl, mesh->netns)) {
+		((struct sockaddr_in *)&sn)->sin_port = ntohs(atoi(mesh->myport));
+		meshlink_hint_address(mesh, (meshlink_node_t *)mesh->self, (struct sockaddr *)&sn);
 	}
 
 	// 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);
+	sl = sizeof(sn);
+
+	if(getlocaladdr("2606:2800:220:1:248:1893:25c8:1946", (struct sockaddr *)&sn, &sl, mesh->netns)) {
+		((struct sockaddr_in6 *)&sn)->sin6_port = ntohs(atoi(mesh->myport));
+		meshlink_hint_address(mesh, (meshlink_node_t *)mesh->self, (struct sockaddr *)&sn);
 	}
 }
 
 static bool meshlink_setup(meshlink_handle_t *mesh) {
-	if(mkdir(mesh->confbase, 0777) && errno != EEXIST) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create directory %s: %s\n", mesh->confbase, strerror(errno));
+	if(!config_init(mesh, "current")) {
+		logger(mesh, MESHLINK_ERROR, "Could not set up configuration in %s/current: %s\n", mesh->confbase, strerror(errno));
 		meshlink_errno = MESHLINK_ESTORAGE;
 		return false;
 	}
 
-	char filename[PATH_MAX];
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts", mesh->confbase);
+	if(!ecdsa_keygen(mesh)) {
+		meshlink_errno = MESHLINK_EINTERNAL;
+		return false;
+	}
+
+	if(check_port(mesh) == 0) {
+		meshlink_errno = MESHLINK_ENETWORK;
+		return false;
+	}
 
-	if(mkdir(filename, 0777) && errno != EEXIST) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create directory %s: %s\n", filename, strerror(errno));
+	/* Create a node for ourself */
+
+	mesh->self = new_node();
+	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));
+
+	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));
 		meshlink_errno = MESHLINK_ESTORAGE;
 		return false;
 	}
 
-	snprintf(filename, sizeof(filename), "%s" SLASH "meshlink.conf", mesh->confbase);
+	/* Ensure the configuration directory metadata is on disk */
+	if(!config_sync(mesh, "current")) {
+		return false;
+	}
 
-	if(!access(filename, F_OK)) {
-		logger(mesh, MESHLINK_DEBUG, "Configuration file %s already exists!\n", filename);
-		meshlink_errno = MESHLINK_EEXIST;
+	if(!main_config_lock(mesh)) {
+		logger(NULL, MESHLINK_ERROR, "Cannot lock main config file\n");
+		meshlink_errno = MESHLINK_ESTORAGE;
 		return false;
 	}
 
-	FILE *f = fopen(filename, "w");
+	return true;
+}
 
-	if(!f) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create file %s: %s\n", filename, strerror(errno));
+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;
 	}
 
-	fprintf(f, "Name = %s\n", mesh->name);
-	fclose(f);
+	config_t config;
 
-	if(!ecdsa_keygen(mesh)) {
-		meshlink_errno = MESHLINK_EINTERNAL;
-		unlink(filename);
+	if(!main_config_read(mesh, "current", &config, mesh->config_key)) {
+		logger(NULL, MESHLINK_ERROR, "Could not read main configuration file!");
 		return false;
 	}
 
-	if(check_port(mesh) == 0) {
-		meshlink_errno = MESHLINK_ENETWORK;
-		unlink(filename);
+	packmsg_input_t in = {config.buf, config.len};
+	const void *private_key;
+	const void *invitation_key;
+
+	uint32_t version = packmsg_get_uint32(&in);
+	char *name = packmsg_get_str_dup(&in);
+	uint32_t private_key_len = packmsg_get_bin_raw(&in, &private_key);
+	uint32_t invitation_key_len = packmsg_get_bin_raw(&in, &invitation_key);
+	uint16_t myport = packmsg_get_uint16(&in);
+
+	if(!packmsg_done(&in) || version != MESHLINK_CONFIG_VERSION || private_key_len != 96 || invitation_key_len != 96) {
+		logger(NULL, MESHLINK_ERROR, "Error parsing main configuration file!");
+		free(name);
+		config_free(&config);
+		return false;
+	}
+
+#if 0
+
+	// TODO: check this?
+	if(mesh->name && strcmp(mesh->name, name)) {
+		logger(NULL, MESHLINK_ERROR, "Configuration is for a different name (%s)!", name);
+		meshlink_errno = MESHLINK_ESTORAGE;
+		free(name);
+		config_free(&config);
+		return false;
+	}
+
+#endif
+
+	free(mesh->name);
+	mesh->name = name;
+	xasprintf(&mesh->myport, "%u", myport);
+	mesh->private_key = ecdsa_set_private_key(private_key);
+	mesh->invitation_key = ecdsa_set_private_key(invitation_key);
+	config_free(&config);
+
+	/* Create a node for ourself and read our host configuration file */
+
+	mesh->self = new_node();
+	mesh->self->name = xstrdup(name);
+	mesh->self->devclass = mesh->devclass;
+
+	if(!node_read_public_key(mesh, mesh->self)) {
+		logger(NULL, MESHLINK_ERROR, "Could not read our host configuration file!");
+		meshlink_errno = MESHLINK_ESTORAGE;
+		free_node(mesh->self);
+		mesh->self = NULL;
 		return false;
 	}
 
 	return true;
 }
 
-meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
-	// Validate arguments provided by the application
-	bool usingname = false;
+#ifdef HAVE_SETNS
+static void *setup_network_in_netns_thread(void *arg) {
+	meshlink_handle_t *mesh = arg;
 
-	logger(NULL, MESHLINK_DEBUG, "meshlink_open called\n");
+	if(setns(mesh->netns, CLONE_NEWNET) != 0) {
+		return NULL;
+	}
+
+	bool success = setup_network(mesh);
+	add_local_addresses(mesh);
+	return success ? arg : NULL;
+}
+#endif // HAVE_SETNS
 
+meshlink_open_params_t *meshlink_open_params_init(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
 	if(!confbase || !*confbase) {
 		logger(NULL, MESHLINK_ERROR, "No confbase given!\n");
 		meshlink_errno = MESHLINK_EINVAL;
@@ -1056,11 +1013,244 @@ meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const c
 	}
 
 	if(!name || !*name) {
+		logger(NULL, MESHLINK_ERROR, "No name given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	};
+
+	if(!check_id(name)) {
+		logger(NULL, MESHLINK_ERROR, "Invalid name given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(devclass < 0 || devclass >= DEV_CLASS_COUNT) {
+		logger(NULL, MESHLINK_ERROR, "Invalid devclass given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	meshlink_open_params_t *params = xzalloc(sizeof * params);
+
+	params->confbase = xstrdup(confbase);
+	params->name = xstrdup(name);
+	params->appname = xstrdup(appname);
+	params->devclass = devclass;
+	params->netns = -1;
+
+	return params;
+}
+
+bool meshlink_open_params_set_netns(meshlink_open_params_t *params, int netns) {
+	if(!params) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	params->netns = netns;
+
+	return true;
+}
+
+bool meshlink_open_params_set_storage_key(meshlink_open_params_t *params, const void *key, size_t keylen) {
+	if(!params) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if((!key && keylen) || (key && !keylen)) {
+		logger(NULL, MESHLINK_ERROR, "Invalid key length!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	params->key = key;
+	params->keylen = keylen;
+
+	return true;
+}
+
+bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key, size_t new_keylen) {
+	if(!mesh || !new_key || !new_keylen) {
+		logger(mesh, MESHLINK_ERROR, "Invalid arguments given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	// Create hash for the new key
+	void *new_config_key;
+	new_config_key = xmalloc(CHACHA_POLY1305_KEYLEN);
+
+	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);
+		return false;
+	}
+
+	// Copy contents of the "current" confbase sub-directory to "new" confbase sub-directory with the 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);
+		return false;
+	}
+
+	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;
+	}
+
+	devtool_keyrotate_probe(2);
+
+	// Rename confbase/new/ to confbase/current
+
+	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")) {
+		pthread_mutex_unlock(&mesh->mutex);
+		return false;
+	}
+
+	// Change the mesh handle key with new key
+
+	free(mesh->config_key);
+	mesh->config_key = new_config_key;
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return true;
+}
+
+void meshlink_open_params_free(meshlink_open_params_t *params) {
+	if(!params) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	free(params->confbase);
+	free(params->name);
+	free(params->appname);
+
+	free(params);
+}
+
+/// Device class traits
+static const dev_class_traits_t default_class_traits[DEV_CLASS_COUNT] = {
+	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 3, .max_connects = 10000, .edge_weight = 1 }, // DEV_CLASS_BACKBONE
+	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 3, .max_connects = 100, .edge_weight = 3 },   // DEV_CLASS_STATIONARY
+	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 3, .max_connects = 3, .edge_weight = 6 },     // DEV_CLASS_PORTABLE
+	{ .pingtimeout = 5, .pinginterval = 60, .min_connects = 1, .max_connects = 1, .edge_weight = 9 },     // DEV_CLASS_UNKNOWN
+};
+
+meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
+	if(!confbase || !*confbase) {
+		logger(NULL, MESHLINK_ERROR, "No confbase given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	/* Create a temporary struct on the stack, to avoid allocating and freeing one. */
+	meshlink_open_params_t params;
+	memset(&params, 0, sizeof(params));
+
+	params.confbase = (char *)confbase;
+	params.name = (char *)name;
+	params.appname = (char *)appname;
+	params.devclass = devclass;
+	params.netns = -1;
+
+	return meshlink_open_ex(&params);
+}
+
+meshlink_handle_t *meshlink_open_encrypted(const char *confbase, const char *name, const char *appname, dev_class_t devclass, const void *key, size_t keylen) {
+	if(!confbase || !*confbase) {
+		logger(NULL, MESHLINK_ERROR, "No confbase given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	/* Create a temporary struct on the stack, to avoid allocating and freeing one. */
+	meshlink_open_params_t params;
+	memset(&params, 0, sizeof(params));
+
+	params.confbase = (char *)confbase;
+	params.name = (char *)name;
+	params.appname = (char *)appname;
+	params.devclass = devclass;
+	params.netns = -1;
+
+	if(!meshlink_open_params_set_storage_key(&params, key, keylen)) {
+		return false;
+	}
+
+	return meshlink_open_ex(&params);
+}
+
+meshlink_handle_t *meshlink_open_ephemeral(const char *name, const char *appname, dev_class_t devclass) {
+	/* Create a temporary struct on the stack, to avoid allocating and freeing one. */
+	meshlink_open_params_t params;
+	memset(&params, 0, sizeof(params));
+
+	params.name = (char *)name;
+	params.appname = (char *)appname;
+	params.devclass = devclass;
+	params.netns = -1;
+
+	return meshlink_open_ex(&params);
+}
+
+meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
+	// Validate arguments provided by the application
+	bool usingname = false;
+
+	logger(NULL, MESHLINK_DEBUG, "meshlink_open called\n");
+
+	if(!params->appname || !*params->appname) {
+		logger(NULL, MESHLINK_ERROR, "No appname given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(strchr(params->appname, ' ')) {
+		logger(NULL, MESHLINK_ERROR, "Invalid appname given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(!params->name || !*params->name) {
 		logger(NULL, MESHLINK_ERROR, "No name given!\n");
 		//return NULL;
 	} else { //check name only if there is a name != NULL
 
-		if(!check_id(name)) {
+		if(!check_id(params->name)) {
 			logger(NULL, MESHLINK_ERROR, "Invalid name given!\n");
 			meshlink_errno = MESHLINK_EINVAL;
 			return NULL;
@@ -1069,28 +1259,58 @@ meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const c
 		}
 	}
 
-	if((int)devclass < 0 || devclass > _DEV_CLASS_MAX) {
+	if(params->devclass < 0 || params->devclass >= DEV_CLASS_COUNT) {
 		logger(NULL, MESHLINK_ERROR, "Invalid devclass given!\n");
 		meshlink_errno = MESHLINK_EINVAL;
 		return NULL;
 	}
 
+	if((params->key && !params->keylen) || (!params->key && params->keylen)) {
+		logger(NULL, MESHLINK_ERROR, "Invalid key length!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
 	meshlink_handle_t *mesh = xzalloc(sizeof(meshlink_handle_t));
-	mesh->confbase = xstrdup(confbase);
-	mesh->appname = xstrdup(appname);
-	mesh->devclass = devclass;
+
+	if(params->confbase) {
+		mesh->confbase = xstrdup(params->confbase);
+	}
+
+	mesh->appname = xstrdup(params->appname);
+	mesh->devclass = params->devclass;
 	mesh->discovery = true;
 	mesh->invitation_timeout = 604800; // 1 week
+	mesh->netns = params->netns;
+	mesh->submeshes = NULL;
+	mesh->log_cb = global_log_cb;
+	mesh->log_level = global_log_level;
+
+	randomize(&mesh->prng_state, sizeof(mesh->prng_state));
+
+	memcpy(mesh->dev_class_traits, default_class_traits, sizeof(default_class_traits));
 
 	if(usingname) {
-		mesh->name = xstrdup(name);
+		mesh->name = xstrdup(params->name);
+	}
+
+	// Hash the key
+	if(params->key) {
+		mesh->config_key = xmalloc(CHACHA_POLY1305_KEYLEN);
+
+		if(!prf(params->key, params->keylen, "MeshLink configuration key", 26, mesh->config_key, CHACHA_POLY1305_KEYLEN)) {
+			logger(NULL, MESHLINK_ERROR, "Error creating configuration key!\n");
+			meshlink_close(mesh);
+			meshlink_errno = MESHLINK_EINTERNAL;
+			return NULL;
+		}
 	}
 
 	// initialize mutex
 	pthread_mutexattr_t attr;
 	pthread_mutexattr_init(&attr);
 	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
-	pthread_mutex_init(&(mesh->mesh_mutex), &attr);
+	pthread_mutex_init(&mesh->mutex, &attr);
 
 	mesh->threadstarted = false;
 	event_loop_init(&mesh->loop);
@@ -1098,79 +1318,59 @@ meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const c
 
 	meshlink_queue_init(&mesh->outpacketqueue);
 
-	// Check whether meshlink.conf already exists
+	// If no configuration exists yet, create it.
 
-	char filename[PATH_MAX];
-	snprintf(filename, sizeof(filename), "%s" SLASH "meshlink.conf", confbase);
-
-	if(access(filename, R_OK)) {
-		if(errno == ENOENT) {
-			// If not, create it
-			if(!meshlink_setup(mesh)) {
-				// meshlink_errno is set by meshlink_setup()
-				return NULL;
-			}
-		} else {
-			logger(NULL, MESHLINK_ERROR, "Cannot not read from %s: %s\n", filename, strerror(errno));
+	if(!meshlink_confbase_exists(mesh)) {
+		if(!meshlink_setup(mesh)) {
+			logger(NULL, MESHLINK_ERROR, "Cannot create initial configuration\n");
+			meshlink_close(mesh);
+			return NULL;
+		}
+	} else {
+		if(!meshlink_read_config(mesh)) {
+			logger(NULL, MESHLINK_ERROR, "Cannot read main configuration\n");
 			meshlink_close(mesh);
-			meshlink_errno = MESHLINK_ESTORAGE;
 			return NULL;
 		}
 	}
 
-	// Open the configuration file and lock it
-
-	mesh->conffile = fopen(filename, "r");
-
-	if(!mesh->conffile) {
-		logger(NULL, MESHLINK_ERROR, "Cannot not open %s: %s\n", filename, strerror(errno));
-		meshlink_close(mesh);
-		meshlink_errno = MESHLINK_ESTORAGE;
-		return NULL;
-	}
-
-#ifdef FD_CLOEXEC
-	fcntl(fileno(mesh->conffile), F_SETFD, FD_CLOEXEC);
-#endif
-
 #ifdef HAVE_MINGW
-	// TODO: use _locking()?
-#else
-	if(flock(fileno(mesh->conffile), LOCK_EX | LOCK_NB) != 0) {
-		logger(NULL, MESHLINK_ERROR, "Cannot lock %s: %s\n", filename, strerror(errno));
-		meshlink_close(mesh);
-		meshlink_errno = MESHLINK_EBUSY;
-		return NULL;
-	}
+	struct WSAData wsa_state;
+	WSAStartup(MAKEWORD(2, 2), &wsa_state);
 #endif
 
-	// Read the configuration
-
-	init_configuration(&mesh->config);
+	// Setup up everything
+	// TODO: we should not open listening sockets yet
 
-	if(!read_server_config(mesh)) {
-		meshlink_close(mesh);
-		meshlink_errno = MESHLINK_ESTORAGE;
-		return NULL;
-	};
+	bool success = false;
 
-#ifdef HAVE_MINGW
-	struct WSAData wsa_state;
+	if(mesh->netns != -1) {
+#ifdef HAVE_SETNS
+		pthread_t thr;
 
-	WSAStartup(MAKEWORD(2, 2), &wsa_state);
+		if(pthread_create(&thr, NULL, setup_network_in_netns_thread, mesh) == 0) {
+			void *retval = NULL;
+			success = pthread_join(thr, &retval) == 0 && retval;
+		}
 
-#endif
+#else
+		meshlink_errno = MESHLINK_EINTERNAL;
+		return NULL;
 
-	// Setup up everything
-	// TODO: we should not open listening sockets yet
+#endif // HAVE_SETNS
+	} else {
+		success = setup_network(mesh);
+		add_local_addresses(mesh);
+	}
 
-	if(!setup_network(mesh)) {
+	if(!success) {
 		meshlink_close(mesh);
 		meshlink_errno = MESHLINK_ENETWORK;
 		return NULL;
 	}
 
 	add_local_addresses(mesh);
+	node_write_config(mesh, mesh->self);
 
 	idle_set(&mesh->loop, idle, mesh);
 
@@ -1178,22 +1378,81 @@ meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const c
 	return mesh;
 }
 
+meshlink_submesh_t *meshlink_submesh_open(meshlink_handle_t  *mesh, const char *submesh) {
+	meshlink_submesh_t *s = NULL;
+
+	if(!mesh) {
+		logger(NULL, MESHLINK_ERROR, "No mesh handle given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	if(!submesh || !*submesh) {
+		logger(NULL, MESHLINK_ERROR, "No submesh name given!\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	//lock mesh->nodes
+	pthread_mutex_lock(&mesh->mutex);
+
+	s = (meshlink_submesh_t *)create_submesh(mesh, submesh);
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return s;
+}
+
 static void *meshlink_main_loop(void *arg) {
 	meshlink_handle_t *mesh = arg;
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	if(mesh->netns != -1) {
+#ifdef HAVE_SETNS
 
-	try_outgoing_connections(mesh);
+		if(setns(mesh->netns, CLONE_NEWNET) != 0) {
+			pthread_cond_signal(&mesh->cond);
+			return NULL;
+		}
+
+#else
+		pthread_cond_signal(&mesh->cond);
+		return NULL;
+#endif // HAVE_SETNS
+	}
+
+#if HAVE_CATTA
+
+	if(mesh->discovery) {
+		discovery_start(mesh);
+	}
+
+#endif
+
+	pthread_mutex_lock(&mesh->mutex);
 
 	logger(mesh, MESHLINK_DEBUG, "Starting main_loop...\n");
+	pthread_cond_broadcast(&mesh->cond);
 	main_loop(mesh);
 	logger(mesh, MESHLINK_DEBUG, "main_loop returned.\n");
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
+
+#if HAVE_CATTA
+
+	// Stop discovery
+	if(mesh->discovery) {
+		discovery_stop(mesh);
+	}
+
+#endif
+
 	return NULL;
 }
 
 bool meshlink_start(meshlink_handle_t *mesh) {
+	assert(mesh->self);
+	assert(mesh->private_key);
+
 	if(!mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
@@ -1201,11 +1460,14 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	logger(mesh, MESHLINK_DEBUG, "meshlink_start called\n");
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
+
+	assert(mesh->self->ecdsa);
+	assert(!memcmp((uint8_t *)mesh->self->ecdsa + 64, (uint8_t *)mesh->private_key + 64, 32));
 
 	if(mesh->threadstarted) {
 		logger(mesh, MESHLINK_DEBUG, "thread was already running\n");
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return true;
 	}
 
@@ -1223,10 +1485,12 @@ 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->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
+	init_outgoings(mesh);
+
 	// Start the main thread
 
 	event_loop_start(&mesh->loop);
@@ -1236,21 +1500,14 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 		memset(&mesh->thread, 0, sizeof(mesh)->thread);
 		meshlink_errno = MESHLINK_EINTERNAL;
 		event_loop_stop(&mesh->loop);
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
+	pthread_cond_wait(&mesh->cond, &mesh->mutex);
 	mesh->threadstarted = true;
 
-#if HAVE_CATTA
-
-	if(mesh->discovery) {
-		discovery_start(mesh);
-	}
-
-#endif
-
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 	return true;
 }
 
@@ -1260,18 +1517,9 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		return;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 	logger(mesh, MESHLINK_DEBUG, "meshlink_stop called\n");
 
-#if HAVE_CATTA
-
-	// Stop discovery
-	if(mesh->discovery) {
-		discovery_stop(mesh);
-	}
-
-#endif
-
 	// Shut down the main thread
 	event_loop_stop(&mesh->loop);
 
@@ -1292,9 +1540,9 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 
 	if(mesh->threadstarted) {
 		// Wait for the main thread to finish
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		pthread_join(mesh->thread, NULL);
-		pthread_mutex_lock(&(mesh->mesh_mutex));
+		pthread_mutex_lock(&mesh->mutex);
 
 		mesh->threadstarted = false;
 	}
@@ -1309,16 +1557,23 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		}
 	}
 
-	if(mesh->outgoings) {
-		list_delete_list(mesh->outgoings);
-		mesh->outgoings = NULL;
+	exit_outgoings(mesh);
+
+	// Write out any changed node config files
+	if(mesh->nodes) {
+		for splay_each(node_t, n, mesh->nodes) {
+			if(n->status.dirty) {
+				node_write_config(mesh, n);
+				n->status.dirty = false;
+			}
+		}
 	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 void meshlink_close(meshlink_handle_t *mesh) {
-	if(!mesh || !mesh->confbase) {
+	if(!mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return;
 	}
@@ -1327,7 +1582,7 @@ void meshlink_close(meshlink_handle_t *mesh) {
 	meshlink_stop(mesh);
 
 	// lock is not released after this
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
 	// Close and free all resources used.
 
@@ -1335,7 +1590,6 @@ void meshlink_close(meshlink_handle_t *mesh) {
 
 	logger(mesh, MESHLINK_INFO, "Terminating");
 
-	exit_configuration(&mesh->config);
 	event_loop_exit(&mesh->loop);
 
 #ifdef HAVE_MINGW
@@ -1348,14 +1602,26 @@ void meshlink_close(meshlink_handle_t *mesh) {
 
 	ecdsa_free(mesh->invitation_key);
 
+	if(mesh->netns != -1) {
+		close(mesh->netns);
+	}
+
+	for(vpn_packet_t *packet; (packet = meshlink_queue_pop(&mesh->outpacketqueue));) {
+		free(packet);
+	}
+
+	meshlink_queue_exit(&mesh->outpacketqueue);
+
 	free(mesh->name);
 	free(mesh->appname);
 	free(mesh->confbase);
-	pthread_mutex_destroy(&(mesh->mesh_mutex));
+	free(mesh->config_key);
+	ecdsa_free(mesh->private_key);
+
+	main_config_unlock(mesh);
 
-	if(mesh->conffile) {
-		fclose(mesh->conffile);
-        }
+	pthread_mutex_unlock(&mesh->mutex);
+	pthread_mutex_destroy(&mesh->mutex);
 
 	memset(mesh, 0, sizeof(*mesh));
 
@@ -1368,21 +1634,19 @@ bool meshlink_destroy(const char *confbase) {
 		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;
-		}
+	if(!config_destroy(confbase, "current")) {
+		logger(NULL, MESHLINK_ERROR, "Cannot remove confbase sub-directories %s: %s\n", confbase, strerror(errno));
+		return false;
 	}
 
-	deltree(confbase);
+	config_destroy(confbase, "new");
+	config_destroy(confbase, "old");
+
+	if(rmdir(confbase) && errno != ENOENT) {
+		logger(NULL, MESHLINK_ERROR, "Cannot remove directory %s: %s\n", confbase, strerror(errno));
+		meshlink_errno = MESHLINK_ESTORAGE;
+		return false;
+	}
 
 	return true;
 }
@@ -1393,9 +1657,20 @@ void meshlink_set_receive_cb(meshlink_handle_t *mesh, meshlink_receive_cb_t cb)
 		return;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 	mesh->receive_cb = cb;
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_connection_try_cb(meshlink_handle_t *mesh, meshlink_connection_try_cb_t cb) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+	mesh->connection_try_cb = cb;
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_cb_t cb) {
@@ -1404,9 +1679,20 @@ void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_c
 		return;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 	mesh->node_status_cb = cb;
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_node_pmtu_cb(meshlink_handle_t *mesh, meshlink_node_pmtu_cb_t cb) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+	mesh->node_pmtu_cb = cb;
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_duplicate_cb_t cb) {
@@ -1415,23 +1701,34 @@ void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_dupli
 		return;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 	mesh->node_duplicate_cb = cb;
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 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->mesh_mutex));
+		pthread_mutex_lock(&mesh->mutex);
 		mesh->log_cb = cb;
 		mesh->log_level = cb ? level : 0;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 	} else {
 		global_log_cb = cb;
 		global_log_level = cb ? level : 0;
 	}
 }
 
+void meshlink_set_error_cb(struct meshlink_handle *mesh, meshlink_error_cb_t cb) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+	mesh->error_cb = cb;
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
 bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len) {
 	meshlink_packethdr_t *hdr;
 
@@ -1450,6 +1747,13 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 		return false;
 	}
 
+	node_t *n = (node_t *)destination;
+
+	if(n->status.blacklisted) {
+		logger(mesh, MESHLINK_ERROR, "Node %s blacklisted, dropping packet\n", n->name);
+		return false;
+	}
+
 	// Prepare the packet
 	vpn_packet_t *packet = malloc(sizeof(*packet));
 
@@ -1484,8 +1788,9 @@ bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const
 	return true;
 }
 
-void meshlink_send_from_queue(event_loop_t *loop, meshlink_handle_t *mesh) {
+void meshlink_send_from_queue(event_loop_t *loop, void *data) {
 	(void)loop;
+	meshlink_handle_t *mesh = data;
 	vpn_packet_t *packet = meshlink_queue_pop(&mesh->outpacketqueue);
 
 	if(!packet) {
@@ -1495,6 +1800,8 @@ void meshlink_send_from_queue(event_loop_t *loop, meshlink_handle_t *mesh) {
 	mesh->self->in_packets++;
 	mesh->self->in_bytes += packet->len;
 	route(mesh, mesh->self, packet);
+
+	free(packet);
 }
 
 ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination) {
@@ -1503,19 +1810,19 @@ ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination)
 		return -1;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
 	node_t *n = (node_t *)destination;
 
 	if(!n->status.reachable) {
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return 0;
 
 	} else if(n->mtuprobes > 30 && n->minmtu) {
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return n->minmtu;
 	} else {
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return MTU;
 	}
 }
@@ -1526,13 +1833,13 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return NULL;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
 	node_t *n = (node_t *)node;
 
-	if(!node_read_ecdsa_public_key(mesh, n) || !n->ecdsa) {
+	if(!node_read_public_key(mesh, n) || !n->ecdsa) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
@@ -1542,7 +1849,7 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		meshlink_errno = MESHLINK_EINTERNAL;
 	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 	return fingerprint;
 }
 
@@ -1563,12 +1870,36 @@ meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
 
 	meshlink_node_t *node = NULL;
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 	node = (meshlink_node_t *)lookup_node(mesh, (char *)name); // TODO: make lookup_node() use const
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
+
+	if(!node) {
+		meshlink_errno = MESHLINK_ENOENT;
+	}
+
 	return node;
 }
 
+meshlink_submesh_t *meshlink_get_submesh(meshlink_handle_t *mesh, const char *name) {
+	if(!mesh || !name) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	meshlink_submesh_t *submesh = NULL;
+
+	pthread_mutex_lock(&mesh->mutex);
+	submesh = (meshlink_submesh_t *)lookup_submesh(mesh, name);
+	pthread_mutex_unlock(&mesh->mutex);
+
+	if(!submesh) {
+		meshlink_errno = MESHLINK_ENOENT;
+	}
+
+	return submesh;
+}
+
 meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_t **nodes, size_t *nmemb) {
 	if(!mesh || !nmemb || (*nmemb && !nodes)) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -1578,7 +1909,7 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 	meshlink_node_t **result;
 
 	//lock mesh->nodes
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
 	*nmemb = mesh->nodes->count;
 	result = realloc(nodes, *nmemb * sizeof(*nodes));
@@ -1595,188 +1926,182 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 
 	return result;
 }
 
-bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *signature, size_t *siglen) {
-	if(!mesh || !data || !len || !signature || !siglen) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return false;
+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);
+
+	*nmemb = 0;
+
+	for splay_each(node_t, n, mesh->nodes) {
+		if(true == search_node(n, condition)) {
+			*nmemb = *nmemb + 1;
+		}
 	}
 
-	if(*siglen < MESHLINK_SIGLEN) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return false;
+	if(*nmemb == 0) {
+		free(nodes);
+		pthread_mutex_unlock(&mesh->mutex);
+		return NULL;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	result = realloc(nodes, *nmemb * sizeof(*nodes));
 
-	if(!ecdsa_sign(mesh->self->connection->ecdsa, data, len, signature)) {
-		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
-		return false;
+	if(result) {
+		meshlink_node_t **p = result;
+
+		for splay_each(node_t, n, mesh->nodes) {
+			if(true == search_node(n, condition)) {
+				*p++ = (meshlink_node_t *)n;
+			}
+		}
+	} else {
+		*nmemb = 0;
+		free(nodes);
+		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	*siglen = MESHLINK_SIGLEN;
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
-	return true;
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return result;
 }
 
-bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const void *data, size_t len, const void *signature, size_t siglen) {
-	if(!mesh || !data || !len || !signature) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return false;
+static bool search_node_by_dev_class(const node_t *node, const void *condition) {
+	dev_class_t *devclass = (dev_class_t *)condition;
+
+	if(*devclass == (dev_class_t)node->devclass) {
+		return true;
 	}
 
-	if(siglen != MESHLINK_SIGLEN) {
-		meshlink_errno = MESHLINK_EINVAL;
-		return false;
+	return false;
+}
+
+static bool search_node_by_submesh(const node_t *node, const void *condition) {
+	if(condition == node->submesh) {
+		return true;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	return false;
+}
 
-	bool rval = false;
+meshlink_node_t **meshlink_get_all_nodes_by_dev_class(meshlink_handle_t *mesh, dev_class_t devclass, meshlink_node_t **nodes, size_t *nmemb) {
+	if(!mesh || devclass < 0 || devclass >= DEV_CLASS_COUNT || !nmemb) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
 
-	struct node_t *n = (struct node_t *)source;
-	node_read_ecdsa_public_key(mesh, n);
+	return meshlink_get_all_nodes_by_condition(mesh, &devclass, nodes, nmemb, search_node_by_dev_class);
+}
 
-	if(!n->ecdsa) {
-		meshlink_errno = MESHLINK_EINTERNAL;
-		rval = false;
-	} else {
-		rval = ecdsa_verify(((struct node_t *)source)->ecdsa, data, len, signature);
+meshlink_node_t **meshlink_get_all_nodes_by_submesh(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, meshlink_node_t **nodes, size_t *nmemb) {
+	if(!mesh || !submesh || !nmemb) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
 	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
-	return rval;
+	return meshlink_get_all_nodes_by_condition(mesh, submesh, nodes, nmemb, search_node_by_submesh);
 }
 
-static bool refresh_invitation_key(meshlink_handle_t *mesh) {
-	char filename[PATH_MAX];
+dev_class_t meshlink_get_node_dev_class(meshlink_handle_t *mesh, meshlink_node_t *node) {
+	if(!mesh || !node) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	dev_class_t devclass;
 
-	snprintf(filename, sizeof(filename), "%s" SLASH "invitations", mesh->confbase);
+	pthread_mutex_lock(&mesh->mutex);
 
-	if(mkdir(filename, 0700) && errno != EEXIST) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create directory %s: %s\n", filename, strerror(errno));
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
-		return false;
-	}
+	devclass = ((node_t *)node)->devclass;
 
-	// Count the number of valid invitations, clean up old ones
-	DIR *dir = opendir(filename);
+	pthread_mutex_unlock(&mesh->mutex);
 
-	if(!dir) {
-		logger(mesh, MESHLINK_DEBUG, "Could not read directory %s: %s\n", filename, strerror(errno));
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
-		return false;
+	return devclass;
+}
+
+meshlink_submesh_t *meshlink_get_node_submesh(meshlink_handle_t *mesh, meshlink_node_t *node) {
+	if(!mesh || !node) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
 	}
 
-	errno = 0;
-	int count = 0;
-	struct dirent *ent;
-	time_t deadline = time(NULL) - 604800; // 1 week in the past
+	node_t *n = (node_t *)node;
 
-	while((ent = readdir(dir))) {
-		if(strlen(ent->d_name) != 24) {
-			continue;
-		}
+	meshlink_submesh_t *s;
 
-		char invname[PATH_MAX];
-		struct stat st;
+	s = (meshlink_submesh_t *)n->submesh;
 
-		if(snprintf(invname, sizeof(invname), "%s" SLASH "%s", filename, ent->d_name) >= PATH_MAX) {
-			logger(mesh, MESHLINK_DEBUG, "Filename too long: %s" SLASH "%s", filename, ent->d_name);
-			continue;
-		}
+	return s;
+}
 
-		if(!stat(invname, &st)) {
-			if(mesh->invitation_key && deadline < st.st_mtime) {
-				count++;
-			} else {
-				unlink(invname);
-			}
-		} else {
-			logger(mesh, MESHLINK_DEBUG, "Could not stat %s: %s\n", invname, strerror(errno));
-			errno = 0;
-		}
+bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *signature, size_t *siglen) {
+	if(!mesh || !data || !len || !signature || !siglen) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
 	}
 
-	if(errno) {
-		logger(mesh, MESHLINK_DEBUG, "Error while reading directory %s: %s\n", filename, strerror(errno));
-		closedir(dir);
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+	if(*siglen < MESHLINK_SIGLEN) {
+		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
 
-	closedir(dir);
+	pthread_mutex_lock(&mesh->mutex);
 
-	snprintf(filename, sizeof(filename), "%s" SLASH "invitations" SLASH "ecdsa_key.priv", mesh->confbase);
+	if(!ecdsa_sign(mesh->private_key, data, len, signature)) {
+		meshlink_errno = MESHLINK_EINTERNAL;
+		pthread_mutex_unlock(&mesh->mutex);
+		return false;
+	}
 
-	// Remove the key if there are no outstanding invitations.
-	if(!count) {
-		unlink(filename);
+	*siglen = MESHLINK_SIGLEN;
+	pthread_mutex_unlock(&mesh->mutex);
+	return true;
+}
 
-		if(mesh->invitation_key) {
-			ecdsa_free(mesh->invitation_key);
-			mesh->invitation_key = NULL;
-		}
+bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const void *data, size_t len, const void *signature, size_t siglen) {
+	if(!mesh || !data || !len || !signature) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
 	}
 
-	if(mesh->invitation_key) {
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
-		return true;
+	if(siglen != MESHLINK_SIGLEN) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
 	}
 
-	// Create a new key if necessary.
-	FILE *f = fopen(filename, "rb");
+	pthread_mutex_lock(&mesh->mutex);
 
-	if(!f) {
-		if(errno != ENOENT) {
-			logger(mesh, MESHLINK_DEBUG, "Could not read %s: %s\n", filename, strerror(errno));
-			meshlink_errno = MESHLINK_ESTORAGE;
-			pthread_mutex_unlock(&(mesh->mesh_mutex));
-			return false;
-		}
+	bool rval = false;
 
-		mesh->invitation_key = ecdsa_generate();
+	struct node_t *n = (struct node_t *)source;
 
-		if(!mesh->invitation_key) {
-			logger(mesh, MESHLINK_DEBUG, "Could not generate a new key!\n");
-			meshlink_errno = MESHLINK_EINTERNAL;
-			pthread_mutex_unlock(&(mesh->mesh_mutex));
-			return false;
-		}
+	if(!node_read_public_key(mesh, n)) {
+		meshlink_errno = MESHLINK_EINTERNAL;
+		rval = false;
+	} else {
+		rval = ecdsa_verify(((struct node_t *)source)->ecdsa, data, len, signature);
+	}
 
-		f = fopen(filename, "wb");
+	pthread_mutex_unlock(&mesh->mutex);
+	return rval;
+}
 
-		if(!f) {
-			logger(mesh, MESHLINK_DEBUG, "Could not write %s: %s\n", filename, strerror(errno));
-			meshlink_errno = MESHLINK_ESTORAGE;
-			pthread_mutex_unlock(&(mesh->mesh_mutex));
-			return false;
-		}
+static bool refresh_invitation_key(meshlink_handle_t *mesh) {
+	pthread_mutex_lock(&mesh->mutex);
 
-		chmod(filename, 0600);
-		ecdsa_write_pem_private_key(mesh->invitation_key, f);
-		fclose(f);
-	} else {
-		mesh->invitation_key = ecdsa_read_pem_private_key(f);
-		fclose(f);
+	size_t count = invitation_purge_old(mesh, time(NULL) - mesh->invitation_timeout);
 
-		if(!mesh->invitation_key) {
-			logger(mesh, MESHLINK_DEBUG, "Could not read private key from %s\n", filename);
-			meshlink_errno = MESHLINK_ESTORAGE;
-		}
+	if(!count) {
+		// TODO: Update invitation key if necessary?
 	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
+
 	return mesh->invitation_key;
 }
 
@@ -1806,12 +2131,16 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
 		canonical_address = xstrdup(address);
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
-	bool rval = modify_config_file(mesh, node->name, "CanonicalAddress", canonical_address, 1);
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
-	free(canonical_address);
-	return rval;
+	node_t *n = (node_t *)node;
+	free(n->canonical_address);
+	n->canonical_address = canonical_address;
+	node_write_config(mesh, n);
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return true;
 }
 
 bool meshlink_add_address(meshlink_handle_t *mesh, const char *address) {
@@ -1830,13 +2159,9 @@ bool meshlink_add_external_address(meshlink_handle_t *mesh) {
 		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));
-
+	bool rval = meshlink_add_address(mesh, address);
 	free(address);
+
 	return rval;
 }
 
@@ -1851,7 +2176,13 @@ int meshlink_get_port(meshlink_handle_t *mesh) {
 		return -1;
 	}
 
-	return atoi(mesh->myport);
+	int port;
+
+	pthread_mutex_lock(&mesh->mutex);
+	port = atoi(mesh->myport);
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return port;
 }
 
 bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
@@ -1869,68 +2200,94 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 		return false;
 	}
 
+	devtool_trybind_probe();
+
 	bool rval = false;
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&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;
+	free(mesh->myport);
+	xasprintf(&mesh->myport, "%d", port);
 
-	modify_config_file(mesh, mesh->name, "Port", portstr, true);
+	/* Close down the network. This also deletes mesh->self. */
+	close_network_connections(mesh);
 
-	init_configuration(&mesh->config);
+	/* Recreate mesh->self. */
+	mesh->self = new_node();
+	mesh->self->name = xstrdup(mesh->name);
+	mesh->self->devclass = mesh->devclass;
+	xasprintf(&mesh->myport, "%d", port);
 
-	if(!read_server_config(mesh)) {
+	if(!node_read_public_key(mesh, mesh->self)) {
+		logger(NULL, MESHLINK_ERROR, "Could not read our host configuration file!");
 		meshlink_errno = MESHLINK_ESTORAGE;
+		free_node(mesh->self);
+		mesh->self = NULL;
+		goto done;
 	} else if(!setup_network(mesh)) {
 		meshlink_errno = MESHLINK_ENETWORK;
-	} else {
-		rval = true;
+		goto done;
 	}
 
+	/* Rebuild our own list of recent addresses */
+	memset(mesh->self->recent, 0, sizeof(mesh->self->recent));
+	add_local_addresses(mesh);
+
+	/* Write meshlink.conf with the updated port number */
+	write_main_config_files(mesh);
+
+	rval = config_sync(mesh, "current");
+
 done:
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 
-	return rval;
+	return rval && meshlink_get_port(mesh) == port;
 }
 
 void meshlink_set_invitation_timeout(meshlink_handle_t *mesh, int timeout) {
 	mesh->invitation_timeout = timeout;
 }
 
-char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
+char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, const char *name, uint32_t flags) {
+	meshlink_submesh_t *s = NULL;
+
 	if(!mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return NULL;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	if(submesh) {
+		s = (meshlink_submesh_t *)lookup_submesh(mesh, submesh->name);
+
+		if(s != submesh) {
+			logger(mesh, MESHLINK_DEBUG, "Invalid SubMesh Handle.\n");
+			meshlink_errno = MESHLINK_EINVAL;
+			return NULL;
+		}
+	} else {
+		s = (meshlink_submesh_t *)mesh->self->submesh;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
 
 	// Check validity of the new node's name
 	if(!check_id(name)) {
 		logger(mesh, MESHLINK_DEBUG, "Invalid name for node.\n");
 		meshlink_errno = MESHLINK_EINVAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return NULL;
 	}
 
 	// Ensure no host configuration file with that name exists
-	char filename[PATH_MAX];
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
-
-	if(!access(filename, F_OK)) {
+	if(config_exists(mesh, "current", name)) {
 		logger(mesh, MESHLINK_DEBUG, "A host config file for %s already exists!\n", name);
 		meshlink_errno = MESHLINK_EEXIST;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return NULL;
 	}
 
@@ -1938,23 +2295,23 @@ char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
 	if(meshlink_get_node(mesh, name)) {
 		logger(mesh, MESHLINK_DEBUG, "A node with name %s is already known!\n", name);
 		meshlink_errno = MESHLINK_EEXIST;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return NULL;
 	}
 
 	// Get the local address
-	char *address = get_my_hostname(mesh);
+	char *address = get_my_hostname(mesh, flags);
 
 	if(!address) {
 		logger(mesh, MESHLINK_DEBUG, "No Address known for ourselves!\n");
 		meshlink_errno = MESHLINK_ERESOLV;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return NULL;
 	}
 
 	if(!refresh_invitation_key(mesh)) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return NULL;
 	}
 
@@ -1981,83 +2338,78 @@ char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
 
 	free(fingerprint);
 
-	// Create a file containing the details of the invitation.
-	snprintf(filename, sizeof(filename), "%s" SLASH "invitations" SLASH "%s", mesh->confbase, cookiehash);
-	int ifd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
+	/* Construct the invitation file */
+	uint8_t outbuf[4096];
+	packmsg_output_t inv = {outbuf, sizeof(outbuf)};
+
+	packmsg_add_uint32(&inv, MESHLINK_INVITATION_VERSION);
+	packmsg_add_str(&inv, name);
+	packmsg_add_str(&inv, s ? s->name : CORE_MESH);
+	packmsg_add_int32(&inv, DEV_CLASS_UNKNOWN); /* TODO: allow this to be set by inviter? */
+
+	/* TODO: Add several host config files to bootstrap connections.
+	 * Note: make sure we only add config files of nodes that are in the core mesh or the same submesh,
+	 * and are not blacklisted.
+	 */
+	config_t configs[5];
+	memset(configs, 0, sizeof(configs));
+	int count = 0;
 
-	if(!ifd) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create invitation file %s: %s\n", filename, strerror(errno));
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
-		return NULL;
+	if(config_read(mesh, "current", mesh->self->name, &configs[count], mesh->config_key)) {
+		count++;
 	}
 
-	FILE *f = fdopen(ifd, "w");
+	/* Append host config files to the invitation file */
+	packmsg_add_array(&inv, count);
 
-	if(!f) {
-		abort();
+	for(int i = 0; i < count; i++) {
+		packmsg_add_bin(&inv, configs[i].buf, configs[i].len);
+		config_free(&configs[i]);
 	}
 
-	// Fill in the details.
-	fprintf(f, "Name = %s\n", name);
-	fprintf(f, "ConnectTo = %s\n", mesh->self->name);
+	config_t config = {outbuf, packmsg_output_size(&inv, outbuf)};
 
-	// Copy Broadcast and Mode
-	snprintf(filename, sizeof(filename), "%s" SLASH "meshlink.conf", mesh->confbase);
-	FILE *tc = fopen(filename,  "r");
-
-	if(tc) {
-		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]))) {
-				fputs(buf, f);
-
-				// Make sure there is a newline character.
-				if(!strchr(buf, '\n')) {
-					fputc('\n', f);
-				}
-			}
-		}
-
-		fclose(tc);
-	} else {
-		logger(mesh, MESHLINK_DEBUG, "Could not create %s: %s\n", filename, strerror(errno));
+	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->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return NULL;
 	}
 
-	fprintf(f, "#---------------------------------------------------------------#\n");
-	fprintf(f, "Name = %s\n", mesh->self->name);
-
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
-	fcopy(f, filename);
-	fclose(f);
-
 	// Create an URL from the local address, key hash and cookie
 	char *url;
 	xasprintf(&url, "%s/%s%s", address, hash, cookie);
 	free(address);
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 	return url;
 }
 
+char *meshlink_invite(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, const char *name) {
+	return meshlink_invite_ex(mesh, submesh, name, 0);
+}
+
 bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	if(!mesh || !invitation) {
 		meshlink_errno = MESHLINK_EINVAL;
 		return false;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
 	//Before doing meshlink_join make sure we are not connected to another mesh
 	if(mesh->threadstarted) {
-		logger(mesh, MESHLINK_DEBUG, "Already connected to a mesh\n");
+		logger(mesh, MESHLINK_ERROR, "Cannot join while started\n");
+		meshlink_errno = MESHLINK_EINVAL;
+		pthread_mutex_unlock(&mesh->mutex);
+		return false;
+	}
+
+	// Refuse to join a mesh if we are already part of one. We are part of one if we know at least one other node.
+	if(mesh->nodes->count > 1) {
+		logger(mesh, MESHLINK_ERROR, "Already part of an existing mesh\n");
 		meshlink_errno = MESHLINK_EINVAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
@@ -2091,7 +2443,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
 	if(!key) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
@@ -2137,7 +2489,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
 		if(ai) {
 			for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
-				mesh->sock = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol);
+				mesh->sock = socket_in_netns(aip->ai_family, aip->ai_socktype, aip->ai_protocol, mesh->netns);
 
 				if(mesh->sock == -1) {
 					logger(mesh, MESHLINK_DEBUG, "Could not open socket: %s\n", strerror(errno));
@@ -2169,7 +2521,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	}
 
 	if(mesh->sock == -1) {
-		pthread_mutex_unlock(&mesh->mesh_mutex);
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
@@ -2179,11 +2531,11 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
 	mesh->blen = 0;
 
-	if(!sendline(mesh->sock, "0 ?%s %d.%d %s", b64key, PROT_MAJOR, 1, mesh->appname)) {
+	if(!sendline(mesh->sock, "0 ?%s %d.%d %s", b64key, PROT_MAJOR, PROT_MINOR, mesh->appname)) {
 		logger(mesh, MESHLINK_DEBUG, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
 		closesocket(mesh->sock);
 		meshlink_errno = MESHLINK_ENETWORK;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
@@ -2196,7 +2548,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 		logger(mesh, MESHLINK_DEBUG, "Cannot read greeting from peer\n");
 		closesocket(mesh->sock);
 		meshlink_errno = MESHLINK_ENETWORK;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
@@ -2207,14 +2559,14 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	if(sha512(fingerprint, strlen(fingerprint), hishash)) {
 		logger(mesh, MESHLINK_DEBUG, "Could not create hash\n%s\n", mesh->line + 2);
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
 	if(memcmp(hishash, mesh->hash, 18)) {
 		logger(mesh, MESHLINK_DEBUG, "Peer has an invalid key!\n%s\n", mesh->line + 2);
 		meshlink_errno = MESHLINK_EPEER;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 
 	}
@@ -2223,21 +2575,21 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
 	if(!hiskey) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
 	// Start an SPTPS session
 	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));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
 	// Feed rest of input buffer to SPTPS
 	if(!sptps_receive_data(&mesh->sptps, mesh->buffer, mesh->blen)) {
 		meshlink_errno = MESHLINK_EPEER;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
@@ -2251,13 +2603,13 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
 			logger(mesh, MESHLINK_DEBUG, "Error reading data from %s port %s: %s\n", address, port, strerror(errno));
 			meshlink_errno = MESHLINK_ENETWORK;
-			pthread_mutex_unlock(&(mesh->mesh_mutex));
+			pthread_mutex_unlock(&mesh->mutex);
 			return false;
 		}
 
 		if(!sptps_receive_data(&mesh->sptps, mesh->line, len)) {
 			meshlink_errno = MESHLINK_EPEER;
-			pthread_mutex_unlock(&(mesh->mesh_mutex));
+			pthread_mutex_unlock(&mesh->mutex);
 			return false;
 		}
 	}
@@ -2270,17 +2622,17 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	if(!mesh->success) {
 		logger(mesh, MESHLINK_DEBUG, "Connection closed by peer, invitation cancelled.\n");
 		meshlink_errno = MESHLINK_EPEER;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+		pthread_mutex_unlock(&mesh->mutex);
 		return false;
 	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 	return true;
 
 invalid:
 	logger(mesh, MESHLINK_DEBUG, "Invalid invitation URL\n");
 	meshlink_errno = MESHLINK_EINVAL;
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 	return false;
 }
 
@@ -2290,41 +2642,64 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 		return NULL;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	// Create a config file on the fly.
 
-	char filename[PATH_MAX];
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
-	FILE *f = fopen(filename, "r");
+	uint8_t buf[4096];
+	packmsg_output_t out = {buf, sizeof(buf)};
+	packmsg_add_uint32(&out, MESHLINK_CONFIG_VERSION);
+	packmsg_add_str(&out, mesh->name);
+	packmsg_add_str(&out, CORE_MESH);
 
-	if(!f) {
-		logger(mesh, MESHLINK_DEBUG, "Could not open %s: %s\n", filename, strerror(errno));
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
+
+	packmsg_add_int32(&out, mesh->self->devclass);
+	packmsg_add_bool(&out, mesh->self->status.blacklisted);
+	packmsg_add_bin(&out, ecdsa_get_public_key(mesh->private_key), 32);
+	packmsg_add_str(&out, mesh->self->canonical_address ? mesh->self->canonical_address : "");
+
+	uint32_t count = 0;
+
+	for(uint32_t i = 0; i < 5; i++) {
+		if(mesh->self->recent[i].sa.sa_family) {
+			count++;
+		} else {
+			break;
+		}
+	}
+
+	packmsg_add_array(&out, count);
+
+	for(uint32_t i = 0; i < count; i++) {
+		packmsg_add_sockaddr(&out, &mesh->self->recent[i]);
+	}
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	if(!packmsg_output_ok(&out)) {
+		logger(mesh, MESHLINK_DEBUG, "Error creating export data\n");
+		meshlink_errno = MESHLINK_EINTERNAL;
 		return NULL;
 	}
 
-	fseek(f, 0, SEEK_END);
-	int fsize = ftell(f);
-	rewind(f);
+	// Prepare a base64-encoded packmsg array containing our config file
 
-	size_t len = fsize + 9 + strlen(mesh->self->name);
-	char *buf = xmalloc(len);
-	snprintf(buf, len, "Name = %s\n", mesh->self->name);
+	uint32_t len = packmsg_output_size(&out, buf);
+	uint32_t len2 = ((len + 4) * 4) / 3 + 4;
+	uint8_t *buf2 = xmalloc(len2);
+	packmsg_output_t out2 = {buf2, len2};
+	packmsg_add_array(&out2, 1);
+	packmsg_add_bin(&out2, buf, packmsg_output_size(&out, buf));
 
-	if(fread(buf + len - fsize - 1, fsize, 1, f) != 1) {
-		logger(mesh, MESHLINK_DEBUG, "Error reading from %s: %s\n", filename, strerror(errno));
-		fclose(f);
-		free(buf);
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+	if(!packmsg_output_ok(&out2)) {
+		logger(mesh, MESHLINK_DEBUG, "Error creating export data\n");
+		meshlink_errno = MESHLINK_EINTERNAL;
+		free(buf2);
 		return NULL;
 	}
 
-	fclose(f);
-	buf[len - 1] = 0;
+	b64encode_urlsafe(buf2, (char *)buf2, packmsg_output_size(&out2, buf2));
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
-	return buf;
+	return (char *)buf2;
 }
 
 bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
@@ -2333,68 +2708,87 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		return false;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	size_t datalen = strlen(data);
+	uint8_t *buf = xmalloc(datalen);
+	int buflen = b64decode(data, buf, datalen);
 
-	if(strncmp(data, "Name = ", 7)) {
+	if(!buflen) {
 		logger(mesh, MESHLINK_DEBUG, "Invalid data\n");
 		meshlink_errno = MESHLINK_EPEER;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
 		return false;
 	}
 
-	char *end = strchr(data + 7, '\n');
+	packmsg_input_t in = {buf, buflen};
+	uint32_t count = packmsg_get_array(&in);
 
-	if(!end) {
+	if(!count) {
 		logger(mesh, MESHLINK_DEBUG, "Invalid data\n");
 		meshlink_errno = MESHLINK_EPEER;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
 		return false;
 	}
 
-	int len = end - (data + 7);
-	char name[len + 1];
-	memcpy(name, data + 7, len);
-	name[len] = 0;
+	pthread_mutex_lock(&mesh->mutex);
 
-	if(!check_id(name)) {
-		logger(mesh, MESHLINK_DEBUG, "Invalid Name\n");
-		meshlink_errno = MESHLINK_EPEER;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
-		return false;
-	}
+	while(count--) {
+		const void *data;
+		uint32_t len = packmsg_get_bin_raw(&in, &data);
 
-	char filename[PATH_MAX];
-	snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
+		if(!len) {
+			break;
+		}
 
-	if(!access(filename, F_OK)) {
-		logger(mesh, MESHLINK_DEBUG, "File %s already exists, not importing\n", filename);
-		meshlink_errno = MESHLINK_EEXIST;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
-		return false;
+		packmsg_input_t in2 = {data, len};
+		uint32_t version = packmsg_get_uint32(&in2);
+		char *name = packmsg_get_str_dup(&in2);
+
+		if(!packmsg_input_ok(&in2) || version != MESHLINK_CONFIG_VERSION || !check_id(name)) {
+			free(name);
+			packmsg_input_invalidate(&in);
+			break;
+		}
+
+		if(!check_id(name)) {
+			free(name);
+			break;
+		}
+
+		node_t *n = lookup_node(mesh, name);
+
+		if(n) {
+			logger(mesh, MESHLINK_DEBUG, "Node %s already exists, not importing\n", name);
+			free(name);
+			continue;
+		}
+
+		n = new_node();
+		n->name = name;
+
+		config_t config = {data, len};
+
+		if(!node_read_from_config(mesh, n, &config)) {
+			free_node(n);
+			packmsg_input_invalidate(&in);
+			break;
+		}
+
+		config_write(mesh, "current", n->name, &config, mesh->config_key);
+		node_add(mesh, n);
 	}
 
-	if(errno != ENOENT) {
-		logger(mesh, MESHLINK_DEBUG, "Error accessing %s: %s\n", filename, strerror(errno));
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
+
+	free(buf);
+
+	if(!packmsg_done(&in)) {
+		logger(mesh, MESHLINK_ERROR, "Invalid data\n");
+		meshlink_errno = MESHLINK_EPEER;
 		return false;
 	}
 
-	FILE *f = fopen(filename, "w");
-
-	if(!f) {
-		logger(mesh, MESHLINK_DEBUG, "Could not create %s: %s\n", filename, strerror(errno));
-		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&(mesh->mesh_mutex));
+	if(!config_sync(mesh, "current")) {
 		return false;
 	}
 
-	fwrite(end + 1, strlen(end + 1), 1, f);
-	fclose(f);
-
-	load_all_nodes(mesh);
-
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
 	return true;
 }
 
@@ -2404,15 +2798,29 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
 	node_t *n;
 	n = (node_t *)node;
+
+	if(n == mesh->self) {
+		logger(mesh, MESHLINK_ERROR, "%s blacklisting itself?\n", node->name);
+		meshlink_errno = MESHLINK_EINVAL;
+		pthread_mutex_unlock(&mesh->mutex);
+		return;
+	}
+
+	if(n->status.blacklisted) {
+		logger(mesh, MESHLINK_DEBUG, "Node %s already blacklisted\n", node->name);
+		pthread_mutex_unlock(&mesh->mutex);
+		return;
+	}
+
 	n->status.blacklisted = true;
-	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", node->name);
+	node_write_config(mesh, n);
+	config_sync(mesh, "current");
 
-	//Make blacklisting persistent in the config file
-	append_config_file(mesh, n->name, "blacklisted", "yes");
+	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", node->name);
 
 	//Immediately terminate any connections we have with the blacklisted node
 	for list_each(connection_t, c, mesh->connections) {
@@ -2421,7 +2829,19 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		}
 	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	utcp_abort_all_connections(n->utcp);
+
+	n->mtu = 0;
+	n->minmtu = 0;
+	n->maxmtu = MTU;
+	n->mtuprobes = 0;
+	n->status.udp_confirmed = false;
+
+	if(n->status.reachable) {
+		update_node_status(mesh, n);
+	}
+
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
@@ -2430,14 +2850,26 @@ void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return;
 	}
 
-	pthread_mutex_lock(&(mesh->mesh_mutex));
+	pthread_mutex_lock(&mesh->mutex);
 
 	node_t *n = (node_t *)node;
+
+	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;
+	}
+
 	n->status.blacklisted = false;
+	node_write_config(mesh, n);
+	config_sync(mesh, "current");
 
-	//TODO: remove blacklisted = yes from the config file
+	if(n->status.reachable) {
+		update_node_status(mesh, n);
+	}
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 	return;
 }
 
@@ -2450,34 +2882,18 @@ void meshlink_set_default_blacklist(meshlink_handle_t *mesh, bool blacklist) {
  */
 void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const struct sockaddr *addr) {
 	if(!mesh || !node || !addr) {
+		meshlink_errno = EINVAL;
 		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)) {
-			modify_config_file(mesh, node->name, "Address", str, 5);
-		} else {
-			logger(mesh, MESHLINK_DEBUG, "Not adding Link Local IPv6 Address to config\n");
-		}
-	}
+	pthread_mutex_lock(&mesh->mutex);
 
-	free(str);
-	free(host);
-	free(port);
+	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);
 
-	pthread_mutex_unlock(&(mesh->mesh_mutex));
+	pthread_mutex_unlock(&mesh->mutex);
 	// @TODO do we want to fire off a connection attempt right away?
 }
 
@@ -2488,6 +2904,18 @@ static bool channel_pre_accept(struct utcp *utcp, uint16_t port) {
 	return mesh->channel_accept_cb;
 }
 
+static void aio_signal(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_aio_buffer_t *aio) {
+	if(aio->data) {
+		if(aio->cb.buffer) {
+			aio->cb.buffer(mesh, channel, aio->data, aio->len, aio->priv);
+		}
+	} else {
+		if(aio->cb.fd) {
+			aio->cb.fd(mesh, channel, aio->fd, aio->done, aio->priv);
+		}
+	}
+}
+
 static ssize_t channel_recv(struct utcp_connection *connection, const void *data, size_t len) {
 	meshlink_channel_t *channel = connection->priv;
 
@@ -2500,8 +2928,48 @@ static ssize_t channel_recv(struct utcp_connection *connection, const void *data
 
 	if(n->status.destroyed) {
 		meshlink_channel_close(mesh, channel);
-	} else if(channel->receive_cb) {
-		channel->receive_cb(mesh, channel, data, len);
+		return len;
+	}
+
+	const char *p = data;
+	size_t left = len;
+
+	while(channel->aio_receive) {
+		meshlink_aio_buffer_t *aio = channel->aio_receive;
+		size_t todo = aio->len - aio->done;
+
+		if(todo > left) {
+			todo = left;
+		}
+
+		if(aio->data) {
+			memcpy((char *)aio->data + aio->done, p, todo);
+		} else {
+			ssize_t result = write(aio->fd, p, todo);
+
+			if(result > 0) {
+				todo = result;
+			}
+		}
+
+		aio->done += todo;
+
+		if(aio->done == aio->len) {
+			channel->aio_receive = aio->next;
+			aio_signal(mesh, channel, aio);
+			free(aio);
+		}
+
+		p += todo;
+		left -= todo;
+
+		if(!left && len) {
+			return len;
+		}
+	}
+
+	if(channel->receive_cb) {
+		channel->receive_cb(mesh, channel, p, left);
 	}
 
 	return len;
@@ -2571,16 +3039,69 @@ static void channel_poll(struct utcp_connection *connection, size_t len) {
 
 	node_t *n = channel->node;
 	meshlink_handle_t *mesh = n->mesh;
+	meshlink_aio_buffer_t *aio = channel->aio_send;
+
+	if(aio) {
+		/* We at least one AIO buffer. Send as much as possible form the first buffer. */
+		size_t left = aio->len - aio->done;
+		ssize_t sent;
+
+		if(len > left) {
+			len = left;
+		}
+
+		if(aio->data) {
+			sent = utcp_send(connection, (char *)aio->data + aio->done, len);
+		} else {
+			char buf[65536];
+			size_t todo = utcp_get_sndbuf_free(connection);
+
+			if(todo > left) {
+				todo = left;
+			}
+
+			if(todo > sizeof(buf)) {
+				todo = sizeof(buf);
+			}
+
+			ssize_t result = read(aio->fd, buf, todo);
+
+			if(result > 0) {
+				sent = utcp_send(connection, buf, result);
+			} else {
+				sent = result;
+			}
+		}
+
+		if(sent >= 0) {
+			aio->done += sent;
+		}
 
-	if(channel->poll_cb) {
-		channel->poll_cb(mesh, channel, len);
+		/* If the buffer is now completely sent, call the callback and dispose of it. */
+		if(aio->done >= aio->len) {
+			channel->aio_send = aio->next;
+			aio_signal(mesh, channel, aio);
+			free(aio);
+		}
+	} else {
+		if(channel->poll_cb) {
+			channel->poll_cb(mesh, channel, len);
+		} else {
+			utcp_set_poll_cb(connection, NULL);
+		}
 	}
 }
 
 void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_poll_cb_t cb) {
-	(void)mesh;
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
 	channel->poll_cb = cb;
-	utcp_set_poll_cb(channel->c, cb ? channel_poll : NULL);
+	utcp_set_poll_cb(channel->c, (cb || channel->aio_send) ? channel_poll : NULL);
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb) {
@@ -2589,7 +3110,7 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mesh_mutex);
+	pthread_mutex_lock(&mesh->mutex);
 	mesh->channel_accept_cb = cb;
 	mesh->receive_cb = channel_receive;
 
@@ -2599,7 +3120,33 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 		}
 	}
 
-	pthread_mutex_unlock(&mesh->mesh_mutex);
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_channel_sndbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
+	(void)mesh;
+
+	if(!channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+	utcp_set_sndbuf(channel->c, size);
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
+	(void)mesh;
+
+	if(!channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+	utcp_set_rcvbuf(channel->c, size);
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 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) {
@@ -2612,6 +3159,8 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 		return NULL;
 	}
 
+	pthread_mutex_lock(&mesh->mutex);
+
 	node_t *n = (node_t *)node;
 
 	if(!n->utcp) {
@@ -2620,15 +3169,24 @@ 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);
 			return NULL;
 		}
 	}
 
+	if(n->status.blacklisted) {
+		logger(mesh, MESHLINK_ERROR, "Cannot open a channel with blacklisted node\n");
+		pthread_mutex_unlock(&mesh->mutex);
+		return NULL;
+	}
+
 	meshlink_channel_t *channel = xzalloc(sizeof(*channel));
 	channel->node = n;
 	channel->receive_cb = cb;
 	channel->c = utcp_connect_ex(n->utcp, port, channel_recv, channel, flags);
 
+	pthread_mutex_unlock(&mesh->mutex);
+
 	if(!channel->c) {
 		meshlink_errno = errno == ENOMEM ? MESHLINK_ENOMEM : MESHLINK_EINTERNAL;
 		free(channel);
@@ -2648,7 +3206,9 @@ void meshlink_channel_shutdown(meshlink_handle_t *mesh, meshlink_channel_t *chan
 		return;
 	}
 
+	pthread_mutex_lock(&mesh->mutex);
 	utcp_shutdown(channel->c, direction);
+	pthread_mutex_unlock(&mesh->mutex);
 }
 
 void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
@@ -2657,7 +3217,25 @@ void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel
 		return;
 	}
 
+	pthread_mutex_lock(&mesh->mutex);
+
 	utcp_close(channel->c);
+
+	/* Clean up any outstanding AIO buffers. */
+	for(meshlink_aio_buffer_t *aio = channel->aio_send, *next; aio; aio = next) {
+		next = aio->next;
+		aio_signal(mesh, channel, aio);
+		free(aio);
+	}
+
+	for(meshlink_aio_buffer_t *aio = channel->aio_receive, *next; aio; aio = next) {
+		next = aio->next;
+		aio_signal(mesh, channel, aio);
+		free(aio);
+	}
+
+	pthread_mutex_unlock(&mesh->mutex);
+
 	free(channel);
 }
 
@@ -2678,12 +3256,21 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 
 	// 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,
+	// Then, preferably only if there is room in the receiver window,
 	// kick the meshlink thread to go send packets.
 
-	pthread_mutex_lock(&mesh->mesh_mutex);
-	ssize_t retval = utcp_send(channel->c, data, len);
-	pthread_mutex_unlock(&mesh->mesh_mutex);
+	ssize_t retval;
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	/* Disallow direct calls to utcp_send() while we still have AIO active. */
+	if(channel->aio_send) {
+		retval = 0;
+	} else {
+		retval = utcp_send(channel->c, data, len);
+	}
+
+	pthread_mutex_unlock(&mesh->mutex);
 
 	if(retval < 0) {
 		meshlink_errno = MESHLINK_ENETWORK;
@@ -2692,6 +3279,146 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 	return retval;
 }
 
+bool meshlink_channel_aio_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(!len || !data) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	meshlink_aio_buffer_t *aio = xzalloc(sizeof(*aio));
+	aio->data = data;
+	aio->len = len;
+	aio->cb.buffer = cb;
+	aio->priv = priv;
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	/* Append the AIO buffer descriptor to the end of the chain */
+	meshlink_aio_buffer_t **p = &channel->aio_send;
+
+	while(*p) {
+		p = &(*p)->next;
+	}
+
+	*p = aio;
+
+	/* Ensure the poll callback is set, and call it right now to push data if possible */
+	utcp_set_poll_cb(channel->c, channel_poll);
+	channel_poll(channel->c, len);
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return true;
+}
+
+bool meshlink_channel_aio_fd_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(!len || fd == -1) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	meshlink_aio_buffer_t *aio = xzalloc(sizeof(*aio));
+	aio->fd = fd;
+	aio->len = len;
+	aio->cb.fd = cb;
+	aio->priv = priv;
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	/* Append the AIO buffer descriptor to the end of the chain */
+	meshlink_aio_buffer_t **p = &channel->aio_send;
+
+	while(*p) {
+		p = &(*p)->next;
+	}
+
+	*p = aio;
+
+	/* Ensure the poll callback is set, and call it right now to push data if possible */
+	utcp_set_poll_cb(channel->c, channel_poll);
+	channel_poll(channel->c, len);
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return true;
+}
+
+bool meshlink_channel_aio_receive(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(!len || !data) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	meshlink_aio_buffer_t *aio = xzalloc(sizeof(*aio));
+	aio->data = data;
+	aio->len = len;
+	aio->cb.buffer = cb;
+	aio->priv = priv;
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	/* Append the AIO buffer descriptor to the end of the chain */
+	meshlink_aio_buffer_t **p = &channel->aio_receive;
+
+	while(*p) {
+		p = &(*p)->next;
+	}
+
+	*p = aio;
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return true;
+}
+
+bool meshlink_channel_aio_fd_receive(meshlink_handle_t *mesh, meshlink_channel_t *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(!len || fd == -1) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	meshlink_aio_buffer_t *aio = xzalloc(sizeof(*aio));
+	aio->fd = fd;
+	aio->len = len;
+	aio->cb.fd = cb;
+	aio->priv = priv;
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	/* Append the AIO buffer descriptor to the end of the chain */
+	meshlink_aio_buffer_t **p = &channel->aio_receive;
+
+	while(*p) {
+		p = &(*p)->next;
+	}
+
+	*p = aio;
+
+	pthread_mutex_unlock(&mesh->mutex);
+
+	return true;
+}
+
 uint32_t meshlink_channel_get_flags(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
 	if(!mesh || !channel) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -2701,13 +3428,60 @@ uint32_t meshlink_channel_get_flags(meshlink_handle_t *mesh, meshlink_channel_t
 	return channel->c->flags;
 }
 
+size_t meshlink_channel_get_sendq(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	return utcp_get_sendq(channel->c);
+}
+
+size_t meshlink_channel_get_recvq(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
+	if(!mesh || !channel) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	return utcp_get_recvq(channel->c);
+}
+
+void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t *node, int timeout) {
+	if(!mesh || !node) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return;
+	}
+
+	node_t *n = (node_t *)node;
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	if(!n->utcp) {
+		n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
+	}
+
+	utcp_set_user_timeout(n->utcp, timeout);
+
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
 void update_node_status(meshlink_handle_t *mesh, node_t *n) {
 	if(n->status.reachable && mesh->channel_accept_cb && !n->utcp) {
 		n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
 	}
 
 	if(mesh->node_status_cb) {
-		mesh->node_status_cb(mesh, (meshlink_node_t *)n, n->status.reachable);
+		mesh->node_status_cb(mesh, (meshlink_node_t *)n, n->status.reachable && !n->status.blacklisted);
+	}
+
+	if(mesh->node_pmtu_cb) {
+		mesh->node_pmtu_cb(mesh, (meshlink_node_t *)n, n->minmtu);
+	}
+}
+
+void update_node_pmtu(meshlink_handle_t *mesh, node_t *n) {
+	if(mesh->node_pmtu_cb && !n->status.blacklisted) {
+		mesh->node_pmtu_cb(mesh, (meshlink_node_t *)n, n->minmtu);
 	}
 }
 
@@ -2728,7 +3502,7 @@ void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mesh_mutex);
+	pthread_mutex_lock(&mesh->mutex);
 
 	if(mesh->discovery == enable) {
 		goto end;
@@ -2745,7 +3519,7 @@ void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
 	mesh->discovery = enable;
 
 end:
-	pthread_mutex_unlock(&mesh->mesh_mutex);
+	pthread_mutex_unlock(&mesh->mutex);
 #else
 	(void)mesh;
 	(void)enable;
@@ -2753,21 +3527,53 @@ end:
 #endif
 }
 
+void meshlink_set_dev_class_timeouts(meshlink_handle_t *mesh, dev_class_t devclass, int pinginterval, int pingtimeout) {
+	if(!mesh || devclass < 0 || devclass >= DEV_CLASS_COUNT) {
+		meshlink_errno = EINVAL;
+		return;
+	}
+
+	if(pinginterval < 1 || pingtimeout < 1 || pingtimeout > pinginterval) {
+		meshlink_errno = EINVAL;
+		return;
+	}
+
+	pthread_mutex_lock(&mesh->mutex);
+	mesh->dev_class_traits[devclass].pinginterval = pinginterval;
+	mesh->dev_class_traits[devclass].pingtimeout = pingtimeout;
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+void handle_network_change(meshlink_handle_t *mesh, bool online) {
+	(void)online;
+
+	if(!mesh->connections || !mesh->loop.running) {
+		return;
+	}
+
+	retry(mesh);
+}
+
+void call_error_cb(meshlink_handle_t *mesh, meshlink_errno_t meshlink_errno) {
+	// We should only call the callback function if we are in the background thread.
+	if(!mesh->error_cb) {
+		return;
+	}
+
+	if(!mesh->threadstarted) {
+		return;
+	}
+
+	if(mesh->thread == pthread_self()) {
+		mesh->error_cb(mesh, meshlink_errno);
+	}
+}
+
+
 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) {
 	crypto_exit();
 }
-
-/// 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
-};