X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=92a3eb531cf909072f82eb1a1b1a49f2da116dcd;hp=9e57df5b12c0af0c2f450b30a8d7bd7e93e4fdde;hb=1e89a63f1638e43dee79afbb18d5f733b27d830b;hpb=537c3528863c4736e877c4d1b6c6579940e6df5d

diff --git a/src/net_packet.c b/src/net_packet.c
index 9e57df5b..92a3eb53 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -64,7 +64,7 @@ static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999
 
 static void send_udppacket(node_t *, vpn_packet_t *);
 
-unsigned replaywin = 16;
+unsigned replaywin = 32;
 bool localdiscovery = true;
 bool udp_discovery = true;
 int udp_discovery_keepalive_interval = 10;
@@ -260,7 +260,7 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
 	if(!n->status.validkey_in || !digest_active(n->indigest) || inpkt->len < sizeof(seqno_t) + digest_length(n->indigest))
 		return false;
 
-	return digest_verify(n->indigest, SEQNO(inpkt), inpkt->len - digest_length(n->indigest), DATA(inpkt) + inpkt->len - digest_length(n->indigest));
+	return digest_verify(n->indigest, inpkt->data, inpkt->len - digest_length(n->indigest), inpkt->data + inpkt->len - digest_length(n->indigest));
 #endif
 }
 
@@ -428,6 +428,51 @@ void receive_tcppacket(connection_t *c, const char *buffer, int len) {
 	receive_packet(c->node, &outpkt);
 }
 
+bool receive_tcppacket_sptps(connection_t *c, const char *data, int len) {
+	if (len < sizeof(node_id_t) + sizeof(node_id_t)) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Got too short TCP SPTPS packet from %s (%s)", c->name, c->hostname);
+		return false;
+	}
+
+	node_t *to = lookup_node_id((node_id_t *)data);
+	data += sizeof(node_id_t); len -= sizeof(node_id_t);
+	if(!to) {
+		logger(DEBUG_PROTOCOL, LOG_ERR, "Got TCP SPTPS packet from %s (%s) with unknown destination ID", c->name, c->hostname);
+		return true;
+	}
+
+	node_t *from = lookup_node_id((node_id_t *)data);
+	data += sizeof(node_id_t); len -= sizeof(node_id_t);
+	if(!from) {
+		logger(DEBUG_PROTOCOL, LOG_ERR, "Got TCP SPTPS packet from %s (%s) with unknown source ID", c->name, c->hostname);
+		return true;
+	}
+
+	/* Help the sender reach us over UDP.
+	   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(to->via == myself)
+		send_udp_info(myself, from);
+
+	/* If we're not the final recipient, relay the packet. */
+
+	if(to != myself) {
+		send_sptps_data(to, from, 0, data, len);
+		try_tx(to, true);
+		return true;
+	}
+
+	/* 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);
+		return true;
+	}
+	sptps_receive_data(&from->sptps, data, len);
+	send_mtu_info(myself, from, MTU);
+	return true;
+}
+
 static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
 	if(!n->status.validkey && !n->connection)
 		return;
@@ -681,26 +726,34 @@ end:
 #endif
 }
 
-static bool send_sptps_data_priv(node_t *to, node_t *from, int type, const void *data, size_t len) {
+bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_t len) {
 	node_t *relay = (to->via != myself && (type == PKT_PROBE || (len - SPTPS_DATAGRAM_OVERHEAD) <= to->via->minmtu)) ? to->via : to->nexthop;
 	bool direct = from == myself && to == relay;
 	bool relay_supported = (relay->options >> 24) >= 4;
 	bool tcponly = (myself->options | relay->options) & OPTION_TCPONLY;
 
-	/* 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.
-	   TODO: When relaying, the original sender does not know the end-to-end PMTU (it only knows the PMTU of the first hop).
-	         This can lead to scenarios where large packets are sent over UDP to relay, but then relay has no choice but fall back to TCP. */
+	/* 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(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;
+			memcpy(buf_ptr, data, len); buf_ptr += len;
+			logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet from %s (%s) to %s (%s) via %s (%s) (TCP)", from->name, from->hostname, to->name, to->hostname, to->nexthop->name, to->nexthop->hostname);
+			return send_sptps_tcppacket(to->nexthop->connection, buf, sizeof buf);
+		}
+
 		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 {
-			return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, from->name, to->name, REQ_SPTPS, buf);
+			return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, from->name, to->name, SPTPS_PACKET, buf);
 		}
 	}
 
@@ -727,7 +780,7 @@ static bool send_sptps_data_priv(node_t *to, node_t *from, int type, const void
 		choose_local_address(relay, &sa, &sock);
 	if(!sa)
 		choose_udp_address(relay, &sa, &sock);
-	logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet from %s (%s) to %s (%s) via %s (%s)", from->name, from->hostname, to->name, to->hostname, relay->name, relay->hostname);
+	logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet from %s (%s) to %s (%s) via %s (%s) (UDP)", from->name, from->hostname, to->name, to->hostname, relay->name, relay->hostname);
 	if(sendto(listen_socket[sock].udp.fd, buf, buf_ptr - buf, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
 		if(sockmsgsize(sockerrno)) {
 			// Compensate for SPTPS overhead
@@ -746,10 +799,6 @@ static bool send_sptps_data_priv(node_t *to, node_t *from, int type, const void
 	return true;
 }
 
-bool send_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
-	return send_sptps_data_priv(handle, myself, type, data, len);
-}
-
 bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t len) {
 	node_t *from = handle;
 
@@ -1125,23 +1174,31 @@ static void try_tx_sptps(node_t *n, bool mtu) {
 
 	try_sptps(n);
 
-	/* Do we need to relay packets? */
+	/* Do we need to statically relay packets? */
 
 	node_t *via = (n->via == myself) ? n->nexthop : n->via;
 
-	/* If the relay doesn't support SPTPS, everything goes via TCP anyway. */
+	/* If the static relay doesn't support SPTPS, everything goes via TCP anyway. */
 
 	if((via->options >> 24) < 4)
 		return;
 
-	/* If we do have a relay, try everything with that one instead. */
+	/* If we do have a static relay, try everything with that one instead. */
 
 	if(via != n)
 		return try_tx_sptps(via, mtu);
 
+	/* Otherwise, try to establish UDP connectivity. */
+
 	try_udp(n);
 	if(mtu)
 		try_mtu(n);
+
+	/* If we don't have UDP connectivity (yet), we need to use a dynamic relay (nexthop)
+	   while we try to establish direct connectivity. */
+
+	if(!n->status.udp_confirmed && n != n->nexthop && (n->nexthop->options >> 24) >= 4)
+		try_tx_sptps(n->nexthop, mtu);
 }
 
 static void try_tx_legacy(node_t *n, bool mtu) {
@@ -1386,8 +1443,20 @@ skip_harder:
 			return;
 		}
 
+		/* The packet is supposed to come from the originator or its static relay
+		   (i.e. with no dynamic relays in between).
+		   If it did not, "help" the static relay by sending it UDP info.
+		   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(n != from->via && to->via == myself)
+			send_udp_info(myself, from);
+
+		/* If we're not the final recipient, relay the packet. */
+
 		if(to != myself) {
-			send_sptps_data_priv(to, n, 0, DATA(&pkt), pkt.len - 2 * sizeof(node_id_t));
+			send_sptps_data(to, from, 0, DATA(&pkt), pkt.len - 2 * sizeof(node_id_t));
+			try_tx_sptps(to, true);
 			return;
 		}
 	} else {
@@ -1402,6 +1471,12 @@ skip_harder:
 	n->sock = ls - listen_socket;
 	if(direct && sockaddrcmp(&addr, &n->address))
 		update_node_udp(n, &addr);
+
+	/* If the packet went through a relay, help the sender find the appropriate MTU
+	   through the relay path. */
+
+	if(!direct)
+		send_mtu_info(myself, n, MTU);
 }
 
 void handle_device_data(void *data, int flags) {