X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=19ad29cbdd50780af9bc8afafe7b59cef3b895d1;hb=1296f715b57c88c17299cacadaccdc0be898e0b1;hp=40cb2bac1443783a0803e4f21e277ea252e0398f;hpb=9bb230f30f665779eb89dcce077a15360ec50be1;p=tinc

diff --git a/src/net_packet.c b/src/net_packet.c
index 40cb2bac..19ad29cb 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;
@@ -681,15 +681,13 @@ 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)) {
 		char buf[len * 4 / 3 + 5];
@@ -746,10 +744,6 @@ 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;
 
@@ -1137,7 +1131,7 @@ static void try_tx_sptps(node_t *n, bool mtu) {
 	/* If we do have a static relay, try everything with that one instead. */
 
 	if(via != n)
-		try_tx_sptps(via, mtu);
+		return try_tx_sptps(via, mtu);
 
 	/* Otherwise, try to establish UDP connectivity. */
 
@@ -1406,8 +1400,8 @@ skip_harder:
 		/* 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));
-			try_tx_sptps(n, true);
+			send_sptps_data(to, from, 0, DATA(&pkt), pkt.len - 2 * sizeof(node_id_t));
+			try_tx_sptps(to, true);
 			return;
 		}
 	} else {
@@ -1422,6 +1416,12 @@ 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) {