Ignore ADD_EDGE messages we know are outdated.

A node reconnecting after a network error might send outdated ADD_EDGE
messages. If we see this for an edge we own, we send back a correction.
However, if we don't own the edge but we are one of the edges endpoints,
we ignore it and let the other side, which is the owner, take care of
sending a correction.

This change avoids us from incorrectly learning an old session ID for a
node, which might cause channels to that node to be closed prematurely.

diff --git a/src/protocol_edge.c b/src/protocol_edge.c
index 38dd56f85becc94f9a86339eb4c3c1af2dc36ed4..a2ab2679393e307250b49425a01e2e1ea69d84fa 100644 (file)
--- a/src/protocol_edge.c
+++ b/src/protocol_edge.c
@@ -201,10 +201,16 @@ bool add_edge_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
        if(e) {
                if(e->weight != weight || e->session_id != session_id || sockaddrcmp(&e->address, &address)) {
                        if(from == mesh->self) {
+                               /* The sender has outdated information, we own this edge to send a correction back */
                                logger(mesh, MESHLINK_DEBUG, "Got %s from %s for ourself which does not match existing entry", "ADD_EDGE", c->name);
                                send_add_edge(mesh, c, e, 0);
                                return true;
+                       } else if(to == mesh->self && from != c->node && from->status.reachable) {
+                               /* The sender has outdated information, someone else owns this node so they will correct */
+                               logger(mesh, MESHLINK_DEBUG, "Got %s from %s which does not match existing entry, ignoring", "ADD_EDGE", c->name);
+                               return true;
                        } else {
+                               /* Might be outdated, but update our information, another node will send a correction if necessary */
                                logger(mesh, MESHLINK_DEBUG, "Got %s from %s which does not match existing entry", "ADD_EDGE", c->name);
                                edge_del(mesh, e);
                        }