Use addresses learned from other nodes when making outgoing connections.

[tinc] / src / net_socket.c

diff --git a/src/net_socket.c b/src/net_socket.c
index 30b36a7..a41b887 100644 (file)
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -547,6 +547,39 @@ begin:
        return true;
 }
 
+// Find edges pointing to this node, and use them to build a list of unique, known addresses.
+static struct addrinfo *get_known_addresses(node_t *n) {
+       struct addrinfo *ai = NULL;
+
+       for splay_each(edge_t, e, n->edge_tree) {
+               if(!e->reverse)
+                       continue;
+
+               bool found = false;
+               for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
+                       if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
+                               found = true;
+                               break;
+                       }
+               }
+               if(found)
+                       continue;
+
+               struct addrinfo *nai = xzalloc(sizeof *nai);
+               if(ai)
+                       ai->ai_next = nai;
+               ai = nai;
+               ai->ai_family = e->reverse->address.sa.sa_family;
+               ai->ai_socktype = SOCK_STREAM;
+               ai->ai_protocol = IPPROTO_TCP;
+               ai->ai_addrlen = SALEN(e->reverse->address.sa);
+               ai->ai_addr = xmalloc(ai->ai_addrlen);
+               memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
+       }
+
+       return ai;
+}
+
 void setup_outgoing_connection(outgoing_t *outgoing) {
        timeout_del(&outgoing->ev);
 
@@ -564,8 +597,12 @@ void setup_outgoing_connection(outgoing_t *outgoing) {
        outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
 
        if(!outgoing->cfg) {
-               logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", outgoing->name);
-               return;
+               if(n)
+                       outgoing->aip = outgoing->ai = get_known_addresses(n);
+               if(!outgoing->ai) {
+                       logger(DEBUG_ALWAYS, LOG_ERR, "No address known for %s", outgoing->name);
+                       return;
+               }
        }
 
        do_outgoing_connection(outgoing);