X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol_key.c;h=d24d4aca01af43c968bdc156fd23df4b729448a2;hp=8a12b56874b4580cb109ca59295f1495197a296a;hb=c2dc3784f127ef6db6e9960a4abecc1aab6f4e31;hpb=95921696a49d1eff058880c90a80efd208de959d

diff --git a/src/protocol_key.c b/src/protocol_key.c
index 8a12b568..d24d4aca 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -36,6 +36,7 @@
 static bool mykeyused = false;
 
 void send_key_changed(void) {
+#ifndef DISABLE_LEGACY
 	send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name);
 
 	/* Immediately send new keys to directly connected nodes to keep UDP mappings alive */
@@ -43,6 +44,7 @@ void send_key_changed(void) {
 	for list_each(connection_t, c, connection_list)
 		if(c->edge && c->node && c->node->status.reachable && !c->node->status.sptps)
 			send_ans_key(c->node);
+#endif
 
 	/* Force key exchange for connections using SPTPS */
 
@@ -87,9 +89,13 @@ bool key_changed_h(connection_t *c, const char *request) {
 	return true;
 }
 
+static bool send_sptps_data_myself(void *handle, uint8_t type, const void *data, size_t len) {
+	return send_sptps_data(handle, myself, type, data, len);
+}
+
 static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
 	node_t *to = handle;
-	to->sptps.send_data = send_sptps_data;
+	to->sptps.send_data = send_sptps_data_myself;
 	char buf[len * 4 / 3 + 5];
 	b64encode(data, buf, len);
 	return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_KEY, buf);
@@ -103,9 +109,6 @@ bool send_req_key(node_t *to) {
 			return true;
 		}
 
-		if(to->sptps.label)
-			logger(DEBUG_ALWAYS, LOG_DEBUG, "send_req_key(%s) called while sptps->label != NULL!", to->name);
-
 		char label[25 + strlen(myself->name) + strlen(to->name)];
 		snprintf(label, sizeof label, "tinc UDP key expansion %s %s", myself->name, to->name);
 		sptps_stop(&to->sptps);
@@ -121,7 +124,52 @@ bool send_req_key(node_t *to) {
 
 /* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */
 
-static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, int reqno) {
+static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, node_t *to, int reqno) {
+	/* If this is a SPTPS packet, see if sending UDP info helps.
+	   Note that we only do this if we're the destination or the static relay;
+	   otherwise every hop would initiate its own UDP info message, resulting in elevated chatter. */
+	if((reqno == REQ_KEY || reqno == SPTPS_PACKET) && to->via == myself)
+		send_udp_info(myself, from);
+
+	if(reqno == SPTPS_PACKET) {
+		/* This is a SPTPS data packet. */
+
+		char buf[MAX_STRING_SIZE];
+		int len;
+		if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) {
+			logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s) to %s (%s): %s", "SPTPS_PACKET", from->name, from->hostname, to->name, to->hostname, "invalid SPTPS data");
+			return true;
+		}
+
+		if(to != myself) {
+			/* We don't just forward the request, because we want to use UDP if it's available. */
+			send_sptps_data(to, from, 0, buf, len);
+			try_tx(to, true);
+		} else {
+			/* The packet is for us */
+			if(!sptps_receive_data(&from->sptps, buf, len)) {
+				/* Uh-oh. It might be that the tunnel is stuck in some corrupted state,
+				   so let's restart SPTPS in case that helps. But don't do that too often
+				   to prevent storms. */
+				if(from->last_req_key < now.tv_sec - 10) {
+					logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode TCP packet from %s (%s), restarting SPTPS", from->name, from->hostname);
+					send_req_key(from);
+				}
+				return true;
+			}
+			send_mtu_info(myself, from, MTU);
+		}
+
+		return true;
+	}
+
+	/* Requests that are not SPTPS data packets are forwarded as-is. */
+
+	if (to != myself)
+		return send_request(to->nexthop->connection, "%s", request);
+
+	/* The request is for us */
+
 	switch(reqno) {
 		case REQ_PUBKEY: {
 			if(!node_read_ecdsa_public_key(from)) {
@@ -176,24 +224,7 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, in
 			from->status.validkey = false;
 			from->status.waitingforkey = true;
 			from->last_req_key = now.tv_sec;
-			sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, sizeof label, send_sptps_data, receive_sptps_record);
-			sptps_receive_data(&from->sptps, buf, len);
-			send_mtu_info(myself, from, MTU);
-			return true;
-		}
-
-		case REQ_SPTPS: {
-			if(!from->status.validkey) {
-				logger(DEBUG_PROTOCOL, LOG_ERR, "Got REQ_SPTPS from %s (%s) but we don't have a valid key yet", from->name, from->hostname);
-				return true;
-			}
-
-			char buf[MAX_STRING_SIZE];
-			int len;
-			if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) {
-				logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_SPTPS", from->name, from->hostname, "invalid SPTPS data");
-				return true;
-			}
+			sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, sizeof label, send_sptps_data_myself, receive_sptps_record);
 			sptps_receive_data(&from->sptps, buf, len);
 			send_mtu_info(myself, from, MTU);
 			return true;
@@ -238,19 +269,12 @@ bool req_key_h(connection_t *c, const char *request) {
 		return true;
 	}
 
-	/* If this is a SPTPS packet, see if sending UDP info helps.
-	   Note that we only do this if we're the destination or the static relay;
-	   otherwise every hop would initiate its own UDP info message, resulting in elevated chatter. */
-
-	if(experimental && (reqno == REQ_KEY || reqno == REQ_SPTPS) && to->via == myself)
-		send_udp_info(myself, from);
-
 	/* Check if this key request is for us */
 
 	if(to == myself) {                      /* Yes */
 		/* Is this an extended REQ_KEY message? */
 		if(experimental && reqno)
-			return req_key_ext_h(c, request, from, reqno);
+			return req_key_ext_h(c, request, from, to, reqno);
 
 		/* No, just send our key back */
 		send_ans_key(from);
@@ -264,7 +288,10 @@ bool req_key_h(connection_t *c, const char *request) {
 			return true;
 		}
 
-		/* TODO: forwarding SPTPS packets in this way is inefficient because we send them over TCP without checking for UDP connectivity */
+		/* Is this an extended REQ_KEY message? */
+		if(experimental && reqno)
+			return req_key_ext_h(c, request, from, to, reqno);
+
 		send_request(to->nexthop->connection, "%s", request);
 	}
 
@@ -373,7 +400,7 @@ bool ans_key_h(connection_t *c, const char *request) {
 			return true;
 		}
 
-		if(!*address && from->address.sa.sa_family != AF_UNSPEC) {
+		if(!*address && from->address.sa.sa_family != AF_UNSPEC && to->minmtu) {
 			char *address, *port;
 			logger(DEBUG_PROTOCOL, LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
 			sockaddr2str(&from->address, &address, &port);
@@ -391,7 +418,7 @@ bool ans_key_h(connection_t *c, const char *request) {
 	cipher_close(from->outcipher);
 	digest_close(from->outdigest);
 #endif
-	from->status.validkey = false;
+	if (!from->status.sptps) from->status.validkey = false;
 
 	if(compression < 0 || compression > 11) {
 		logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
@@ -405,9 +432,18 @@ bool ans_key_h(connection_t *c, const char *request) {
 	if(from->status.sptps) {
 		char buf[strlen(key)];
 		int len = b64decode(key, buf, strlen(key));
-
-		if(!len || !sptps_receive_data(&from->sptps, buf, len))
-			logger(DEBUG_ALWAYS, LOG_ERR, "Error processing SPTPS data from %s (%s)", from->name, from->hostname);
+		if(!len || !sptps_receive_data(&from->sptps, buf, len)) {
+			/* Uh-oh. It might be that the tunnel is stuck in some corrupted state,
+			   so let's restart SPTPS in case that helps. But don't do that too often
+			   to prevent storms.
+			   Note that simply relying on handshake timeout is not enough, because
+			   that doesn't apply to key regeneration. */
+			if(from->last_req_key < now.tv_sec - 10) {
+				logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode handshake TCP packet from %s (%s), restarting SPTPS", from->name, from->hostname);
+				send_req_key(from);
+			}
+			return true;
+		}
 
 		if(from->status.validkey) {
 			if(*address && *port) {