X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fprotocol_key.c;h=dbe3d917b779b87126bed3ca23ffcd5324c781a3;hb=7870cb4a1882fb0e3fd4e90784f81327fc0cab08;hp=836737aa7e284e2c11886707d02088ad5a1846a9;hpb=88bd3d78991c721062506be7975f7564be4d82da;p=meshlink

diff --git a/src/protocol_key.c b/src/protocol_key.c
index 836737aa..dbe3d917 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -33,18 +33,10 @@
 
 static const int req_key_timeout = 2;
 
-void send_key_changed(meshlink_handle_t *mesh) {
-	send_request(mesh, mesh->everyone, NULL, "%d %x %s", KEY_CHANGED, rand(), mesh->self->name);
-
-	/* Force key exchange for connections using SPTPS */
-
-	for splay_each(node_t, n, mesh->nodes)
-		if(n->status.reachable && n->status.validkey) {
-			sptps_force_kex(&n->sptps);
-		}
-}
-
 bool key_changed_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+	assert(request);
+	assert(*request);
+
 	char name[MAX_STRING_SIZE];
 	node_t *n;
 
@@ -73,18 +65,44 @@ bool key_changed_h(meshlink_handle_t *mesh, connection_t *c, const char *request
 
 static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
 	(void)type;
+
+	assert(data);
+	assert(len);
+
 	node_t *to = handle;
 	meshlink_handle_t *mesh = to->mesh;
+
+	if(!to->nexthop || !to->nexthop->connection) {
+		logger(mesh, MESHLINK_WARNING, "Cannot send SPTPS data to %s via %s", to->name, to->nexthop ? to->nexthop->name : to->name);
+		return false;
+	}
+
 	to->sptps.send_data = send_sptps_data;
 	char buf[len * 4 / 3 + 5];
 	b64encode(data, buf, len);
 	return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_KEY, buf);
 }
 
+bool send_canonical_address(meshlink_handle_t *mesh, node_t *to) {
+	if(!mesh->self->canonical_address) {
+		return true;
+	}
+
+	return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_CANONICAL, mesh->self->canonical_address);
+}
+
 bool send_req_key(meshlink_handle_t *mesh, node_t *to) {
 	if(!node_read_public_key(mesh, to)) {
 		logger(mesh, MESHLINK_DEBUG, "No ECDSA key known for %s", to->name);
-		send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d", REQ_KEY, mesh->self->name, to->name, REQ_PUBKEY);
+
+		if(!to->nexthop || !to->nexthop->connection) {
+			logger(mesh, MESHLINK_WARNING, "Cannot send REQ_PUBKEY to %s via %s", to->name, to->nexthop ? to->nexthop->name : to->name);
+			return true;
+		}
+
+		char *pubkey = ecdsa_get_base64_public_key(mesh->private_key);
+		send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_PUBKEY, pubkey);
+		free(pubkey);
 		return true;
 	}
 
@@ -92,6 +110,9 @@ bool send_req_key(meshlink_handle_t *mesh, node_t *to) {
 		logger(mesh, MESHLINK_DEBUG, "send_req_key(%s) called while sptps->label != NULL!", to->name);
 	}
 
+	/* Send our canonical address to help with UDP hole punching */
+	send_canonical_address(mesh, to);
+
 	char label[sizeof(meshlink_udp_label) + strlen(mesh->self->name) + strlen(to->name) + 2];
 	snprintf(label, sizeof(label), "%s %s %s", meshlink_udp_label, mesh->self->name, to->name);
 	sptps_stop(&to->sptps);
@@ -106,12 +127,26 @@ bool send_req_key(meshlink_handle_t *mesh, node_t *to) {
 static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *request, node_t *from, int reqno) {
 	(void)c;
 
+	if(!from->nexthop || !from->nexthop->connection) {
+		logger(mesh, MESHLINK_WARNING, "Cannot answer REQ_KEY from %s via %s", from->name, from->nexthop ? from->nexthop->name : from->name);
+		return true;
+	}
+
 	switch(reqno) {
 	case REQ_PUBKEY: {
 		char *pubkey = ecdsa_get_base64_public_key(mesh->private_key);
 
-		if(!from->nexthop || !from->nexthop->connection) {
-			return false;
+		if(!node_read_public_key(mesh, from)) {
+			char hiskey[MAX_STRING_SIZE];
+
+			if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, hiskey) == 1) {
+				from->ecdsa = ecdsa_set_base64_public_key(hiskey);
+
+				if(!from->ecdsa) {
+					logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_PUBKEY", from->name, "invalid pubkey");
+					return true;
+				}
+			}
 		}
 
 		send_request(mesh, from->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, from->name, ANS_PUBKEY, pubkey);
@@ -139,7 +174,7 @@ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *
 		for list_each(outgoing_t, outgoing, mesh->outgoings) {
 			if(outgoing->node == from && outgoing->ev.cb) {
 				outgoing->timeout = 0;
-				timeout_set(&mesh->loop, &outgoing->ev, &(struct timeval) {
+				timeout_set(&mesh->loop, &outgoing->ev, &(struct timespec) {
 					0, 0
 				});
 			}
@@ -181,8 +216,20 @@ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *
 		from->status.validkey = false;
 		from->status.waitingforkey = true;
 		from->last_req_key = mesh->loop.now.tv_sec;
-		sptps_start(&from->sptps, from, false, true, mesh->private_key, from->ecdsa, label, sizeof(label) - 1, send_sptps_data, receive_sptps_record);
-		sptps_receive_data(&from->sptps, buf, len);
+
+		/* Send our canonical address to help with UDP hole punching */
+		send_canonical_address(mesh, from);
+
+		if(!sptps_start(&from->sptps, from, false, true, mesh->private_key, from->ecdsa, label, sizeof(label) - 1, send_sptps_data, receive_sptps_record)) {
+			logger(mesh, MESHLINK_ERROR, "Could not start SPTPS session with %s: %s", from->name, strerror(errno));
+			return true;
+		}
+
+		if(!sptps_receive_data(&from->sptps, buf, len)) {
+			logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", from->name, strerror(errno));
+			return true;
+		}
+
 		return true;
 	}
 
@@ -200,7 +247,33 @@ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *
 			return true;
 		}
 
-		sptps_receive_data(&from->sptps, buf, len);
+		if(!sptps_receive_data(&from->sptps, buf, len)) {
+			logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", from->name, strerror(errno));
+			return true;
+		}
+
+		return true;
+	}
+
+	case REQ_CANONICAL: {
+		char host[MAX_STRING_SIZE];
+		char port[MAX_STRING_SIZE];
+
+		if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING " " MAX_STRING, host, port) != 2) {
+			logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_CANONICAL", from->name, "invalid canonical address");
+			return true;
+		}
+
+		strncat(host, " ", MAX_STRING_SIZE - 1);
+		strncat(host, port, MAX_STRING_SIZE - 1);
+
+		if(from->canonical_address && !strcmp(from->canonical_address, host)) {
+			return true;
+		}
+
+		logger(mesh, MESHLINK_DEBUG, "Updating canonical address of %s to %s", from->name, host);
+		free(from->canonical_address);
+		from->canonical_address = xstrdup(host);
 		return true;
 	}
 
@@ -211,6 +284,9 @@ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *
 }
 
 bool req_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+	assert(request);
+	assert(*request);
+
 	char from_name[MAX_STRING_SIZE];
 	char to_name[MAX_STRING_SIZE];
 	node_t *from, *to;
@@ -253,7 +329,7 @@ bool req_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
 		/* This should never happen. Ignore it, unless it came directly from the connected peer, in which case we disconnect. */
 		return from->connection != c;
 	} else {
-		if(!to->status.reachable) {
+		if(!to->status.reachable || !to->nexthop || !to->nexthop->connection) {
 			logger(mesh, MESHLINK_WARNING, "Got %s from %s destination %s which is not reachable",
 			       "REQ_KEY", c->name, to_name);
 			return true;
@@ -265,13 +341,10 @@ bool req_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
 	return true;
 }
 
-bool send_ans_key(meshlink_handle_t *mesh, node_t *to) {
-	(void)mesh;
-	(void)to;
-	abort();
-}
-
 bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+	assert(request);
+	assert(*request);
+
 	char from_name[MAX_STRING_SIZE];
 	char to_name[MAX_STRING_SIZE];
 	char key[MAX_STRING_SIZE];
@@ -317,35 +390,84 @@ bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
 			return true;
 		}
 
-		if(!*address && from->address.sa.sa_family != AF_UNSPEC) {
-			char *address, *port;
+		if(from == to) {
+			logger(mesh, MESHLINK_WARNING, "Got %s from %s from %s to %s",
+			       "ANS_KEY", c->name, from_name, to_name);
+			return true;
+		}
+
+		if(!to->nexthop || !to->nexthop->connection) {
+			logger(mesh, MESHLINK_WARNING, "Cannot forward ANS_KEY to %s via %s", to->name, to->nexthop ? to->nexthop->name : to->name);
+			return false;
+		}
+
+		/* Append the known UDP address of the from node, if we have a confirmed one */
+		if(!*address && from->status.udp_confirmed && from->address.sa.sa_family != AF_UNSPEC) {
+			char *reflexive_address, *reflexive_port;
 			logger(mesh, MESHLINK_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
-			sockaddr2str(&from->address, &address, &port);
-			send_request(mesh, to->nexthop->connection, NULL, "%s %s %s", request, address, port);
-			free(address);
-			free(port);
+			sockaddr2str(&from->address, &reflexive_address, &reflexive_port);
+			send_request(mesh, to->nexthop->connection, NULL, "%s %s %s", request, reflexive_address, reflexive_port);
+			free(reflexive_address);
+			free(reflexive_port);
 			return true;
 		}
 
 		return send_request(mesh, to->nexthop->connection, NULL, "%s", request);
 	}
 
-	/* Don't use key material until every check has passed. */
-	from->status.validkey = false;
+	/* Is this an ANS_KEY informing us of our own reflexive UDP address? */
+
+	if(from == mesh->self) {
+		if(*key == '.' && *address && *port) {
+			logger(mesh, MESHLINK_DEBUG, "Learned our own reflexive UDP address from %s: %s port %s", c->name, address, port);
+
+			/* Inform all other nodes we want to communicate with and which are reachable via this connection */
+			for splay_each(node_t, n, mesh->nodes) {
+				if(n->nexthop != c->node) {
+					continue;
+				}
+
+				if(n->status.udp_confirmed) {
+					continue;
+				}
+
+				if(!n->status.waitingforkey && !n->status.validkey) {
+					continue;
+				}
+
+				if(!n->nexthop->connection) {
+					continue;
+				}
+
+				logger(mesh, MESHLINK_DEBUG, "Forwarding our own reflexive UDP address to %s", n->name);
+				send_request(mesh, c, NULL, "%d %s %s . -1 -1 -1 0 %s %s", ANS_KEY, mesh->self->name, n->name, address, port);
+			}
+		} else {
+			logger(mesh, MESHLINK_WARNING, "Got %s from %s from %s to %s",
+			       "ANS_KEY", c->name, from_name, to_name);
+		}
 
-	/* Compression is not supported. */
-	if(compression != 0) {
-		logger(mesh, MESHLINK_ERROR, "Node %s uses bogus compression level!", from->name);
 		return true;
 	}
 
-	/* SPTPS or old-style key exchange? */
+	/* Process SPTPS data if present */
 
-	char buf[strlen(key)];
-	int len = b64decode(key, buf, strlen(key));
+	if(*key != '.') {
+		/* Don't use key material until every check has passed. */
+		from->status.validkey = false;
 
-	if(!len || !sptps_receive_data(&from->sptps, buf, len)) {
-		logger(mesh, MESHLINK_ERROR, "Error processing SPTPS data from %s", from->name);
+		/* Compression is not supported. */
+		if(compression != 0) {
+			logger(mesh, MESHLINK_ERROR, "Node %s uses bogus compression level!", from->name);
+			return true;
+		}
+
+		char buf[strlen(key)];
+		int len = b64decode(key, buf, strlen(key));
+
+		if(!len || !sptps_receive_data(&from->sptps, buf, len)) {
+			logger(mesh, MESHLINK_ERROR, "Error processing SPTPS data from %s", from->name);
+		}
 	}
 
 	if(from->status.validkey) {