Merge remote-tracking branch 'dechamps/staticfix' into 1.1

diff --combined src/net_packet.c
index 2e47df4,4598951..245ce62
--- 1/src/net_packet.c
--- 2/src/net_packet.c
+++ b/src/net_packet.c
@@@ -687,7 -687,9 +687,7 @@@ static bool send_sptps_data_priv(node_
        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];
@@@ -1135,7 -1137,7 +1135,7 @@@ static void try_tx_sptps(node_t *n, boo
        /* 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. */
  
@@@ -1392,17 -1394,6 +1392,17 @@@ 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));
                        try_tx_sptps(n, true);
@@@ -1420,12 -1411,6 +1420,12 @@@
        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) {