Avoid allocating packet buffers unnecessarily.

[meshlink] / src / graph.c

diff --git a/src/graph.c b/src/graph.c
index 9955ea41644721a208041de60860329158998e04..b0e0b77a198a408cd2d88aecb2c4debde09022d3 100644 (file)
--- a/src/graph.c
+++ b/src/graph.c
@@ -72,7 +72,7 @@ static void sssp_bfs(meshlink_handle_t *mesh) {
 
        /* Begin with mesh->self */
 
-       mesh->self->status.visited = true;
+       mesh->self->status.visited = mesh->threadstarted;
        mesh->self->nexthop = mesh->self;
        mesh->self->prevedge = NULL;
        mesh->self->distance = 0;
@@ -136,7 +136,13 @@ static void sssp_bfs(meshlink_handle_t *mesh) {
 static void check_reachability(meshlink_handle_t *mesh) {
        /* Check reachability status. */
 
+       int reachable = -1; /* Don't count ourself */
+
        for splay_each(node_t, n, mesh->nodes) {
+               if(n->status.visited) {
+                       reachable++;
+               }
+
                /* Check for nodes that have changed session_id */
                if(n->status.visited && n->prevedge && n->prevedge->reverse->session_id != n->session_id) {
                        n->session_id = n->prevedge->reverse->session_id;
@@ -144,16 +150,45 @@ static void check_reachability(meshlink_handle_t *mesh) {
                        if(n->utcp) {
                                utcp_abort_all_connections(n->utcp);
                        }
+
+                       if(n->status.visited == n->status.reachable) {
+                               /* This session replaces the previous one without changing reachability status.
+                                * We still need to reset the UDP SPTPS state.
+                                */
+                               n->status.validkey = false;
+                               sptps_stop(&n->sptps);
+                               n->status.waitingforkey = false;
+                               n->last_req_key = 0;
+
+                               n->status.udp_confirmed = false;
+                               n->maxmtu = MTU;
+                               n->minmtu = 0;
+                               n->mtuprobes = 0;
+
+                               timeout_del(&mesh->loop, &n->mtutimeout);
+                       }
                }
 
                if(n->status.visited != n->status.reachable) {
                        n->status.reachable = !n->status.reachable;
-                       n->last_state_change = mesh->loop.now.tv_sec;
+                       n->status.dirty = true;
 
-                       if(n->status.reachable) {
-                               logger(mesh, MESHLINK_DEBUG, "Node %s became reachable", n->name);
-                       } else {
-                               logger(mesh, MESHLINK_DEBUG, "Node %s became unreachable", n->name);
+                       if(!n->status.blacklisted) {
+                               if(n->status.reachable) {
+                                       logger(mesh, MESHLINK_DEBUG, "Node %s became reachable", n->name);
+                                       bool first_time_reachable = !n->last_reachable;
+                                       n->last_reachable = time(NULL);
+
+                                       if(first_time_reachable) {
+                                               if(!node_write_config(mesh, n)) {
+                                                       logger(mesh, MESHLINK_WARNING, "Could not write host config file for node %s!\n", n->name);
+
+                                               }
+                                       }
+                               } else {
+                                       logger(mesh, MESHLINK_DEBUG, "Node %s became unreachable", n->name);
+                                       n->last_unreachable = time(NULL);
+                               }
                        }
 
                        /* TODO: only clear status.validkey if node is unreachable? */
@@ -188,6 +223,20 @@ static void check_reachability(meshlink_handle_t *mesh) {
                        }
                }
        }
+
+       if(mesh->reachable != reachable) {
+               if(!reachable) {
+                       mesh->last_unreachable = mesh->loop.now.tv_sec;
+
+                       if(mesh->threadstarted) {
+                               timeout_set(&mesh->loop, &mesh->periodictimer, &(struct timespec) {
+                                       0, prng(mesh, TIMER_FUDGE)
+                               });
+                       }
+               }
+
+               mesh->reachable = reachable;
+       }
 }
 
 void graph(meshlink_handle_t *mesh) {