Don't send MTU probes to nodes we can't reach directly.

[tinc] / src / protocol_key.c

diff --git a/src/protocol_key.c b/src/protocol_key.c
index fcb748f..ebc46f3 100644 (file)
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -124,6 +124,11 @@ bool send_req_key(node_t *to) {
 static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, int reqno) {
        switch(reqno) {
                case REQ_PUBKEY: {
+                       if(!node_read_ecdsa_public_key(from)) {
+                               /* Request their key *before* we send our key back. Otherwise the first SPTPS packet from them will get dropped. */
+                               logger(DEBUG_PROTOCOL, LOG_DEBUG, "Preemptively requesting Ed25519 key for %s (%s)", from->name, from->hostname);
+                               send_request(from->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, from->name, REQ_PUBKEY);
+                       }
                        char *pubkey = ecdsa_get_base64_public_key(myself->connection->ecdsa);
                        send_request(from->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, from->name, ANS_PUBKEY, pubkey);
                        free(pubkey);
@@ -250,6 +255,7 @@ 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 */
                send_request(to->nexthop->connection, "%s", request);
        }
 
@@ -393,7 +399,9 @@ bool ans_key_h(connection_t *c, const char *request) {
                                update_node_udp(from, &sa);
                        }
 
-                       if(from->options & OPTION_PMTU_DISCOVERY && !(from->options & OPTION_TCPONLY))
+                       /* Don't send probes if we can't send UDP packets directly to that node.
+                          TODO: the indirect (via) condition can change at any time as edges are added and removed, so this should probably be moved to graph.c. */
+                       if((from->via == myself || from->via == from) && from->options & OPTION_PMTU_DISCOVERY && !(from->options & OPTION_TCPONLY))
                                send_mtu_probe(from);
                }