X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=8313a54fd0e142c7a9106bd04bd43ddf3b5f661c;hb=1a7a9078c093f77950192c32be009bbe463fe372;hp=f734af299b985475ae80eb92e0b44b7b28d371ea;hpb=fd1cff6df23c3f16a46edaff8a52a7212914b2f0;p=tinc

diff --git a/src/net_packet.c b/src/net_packet.c
index f734af29..8313a54f 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -288,7 +288,14 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 		n->status.udppacket = false;
 
 		if(!result) {
-			logger(DEBUG_TRAFFIC, LOG_ERR, "Got bad packet from %s (%s)", n->name, n->hostname);
+			/* 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, and because that would make life a little too easy
+			   for external attackers trying to DoS us. */
+			if(n->last_req_key < now.tv_sec - 10) {
+				logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode raw TCP packet from %s (%s), restarting SPTPS", n->name, n->hostname);
+				send_req_key(n);
+			}
 			return false;
 		}
 		return true;
@@ -464,11 +471,17 @@ bool receive_tcppacket_sptps(connection_t *c, const char *data, int len) {
 
 	/* The packet is for us */
 
-	if(!from->status.validkey) {
-		logger(DEBUG_PROTOCOL, LOG_ERR, "Got SPTPS packet from %s (%s) but we don't have a valid key yet", from->name, from->hostname);
+	if(!sptps_receive_data(&from->sptps, data, 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 raw TCP packet from %s (%s), restarting SPTPS", from->name, from->hostname);
+			send_req_key(from);
+		}
 		return true;
 	}
-	sptps_receive_data(&from->sptps, data, len);
+
 	send_mtu_info(myself, from, MTU);
 	return true;
 }
@@ -735,7 +748,7 @@ bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_
 	/* Send it via TCP if it is a handshake packet, TCPOnly is in use, this is a relay packet that the other node cannot understand, or this packet is larger than the MTU. */
 
 	if(type == SPTPS_HANDSHAKE || tcponly || (!direct && !relay_supported) || (type != PKT_PROBE && (len - SPTPS_DATAGRAM_OVERHEAD) > relay->minmtu)) {
-		if((from != myself || to->status.validkey) && (to->nexthop->connection->options >> 24) >= 7) {
+		if(type != SPTPS_HANDSHAKE && (to->nexthop->connection->options >> 24) >= 7) {
 			char buf[len + sizeof to->id + sizeof from->id]; char* buf_ptr = buf;
 			memcpy(buf_ptr, &to->id, sizeof to->id); buf_ptr += sizeof to->id;
 			memcpy(buf_ptr, &from->id, sizeof from->id); buf_ptr += sizeof from->id;
@@ -746,9 +759,10 @@ bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_
 
 		char buf[len * 4 / 3 + 5];
 		b64encode(data, buf, len);
-		/* If no valid key is known yet, send the packets using ANS_KEY requests,
-		   to ensure we get to learn the reflexive UDP address. */
-		if(from == myself && !to->status.validkey) {
+		/* If this is a handshake packet, use ANS_KEY instead of REQ_KEY, for two reasons:
+		    - We don't want intermediate nodes to switch to UDP to relay these packets;
+		    - ANS_KEY allows us to learn the reflexive UDP address. */
+		if(type == SPTPS_HANDSHAKE) {
 			to->incompression = myself->incompression;
 			return send_request(to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, from->name, to->name, buf, to->incompression);
 		} else {