Connect to unreachable nodes after enough stable connections exit.

diff --git a/src/net.c b/src/net.c
index 5f50531b9ff4fada055e90b255ecf9b9f03ea351..651c2a3ebb3becb2d940dc6b229d4d302ae0480c 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -152,6 +152,13 @@ static void periodic_handler(event_loop_t *loop, void *data) {
                                nc++;
                }
 
+               /* Count number of unreachable nodes */
+               int num_unreachable = 0;
+               for splay_each(node_t, n, mesh->nodes) {
+                       if(!n->status.reachable)
+                               num_unreachable++;
+               }
+
                if(nc < autoconnect) {
                        /* Not enough active connections, try to add one.
                           Choose a random node, if we don't have a connection to it,
@@ -188,7 +195,47 @@ static void periodic_handler(event_loop_t *loop, void *data) {
                                }
                                break;
                        }
-               } else if(nc > autoconnect) {
+               //} else if(nc > autoconnect) {
+               } else {
+                       /* Min number of connections established. Now try
+                          to connect to some unreachable nodes to attempt
+                          to heal possible partitions.
+                       */
+                       int r = rand() % num_unreachable;
+                       int i = 0;
+
+                       for splay_each(node_t, n, mesh->nodes) {
+                               if(n->status.reachable)
+                                       continue;
+                               
+                               if(i++ != r)
+                                       continue;
+
+                               if(n->connection)
+                                       break;
+
+                               bool found = false;
+
+                               for list_each(outgoing_t, outgoing, mesh->outgoings) {
+                                       if(!strcmp(outgoing->name, n->name)) {
+                                               found = true;
+                                               break;
+                                       }
+                               }
+
+                               if(!found) {
+                                       //TODO: if the node is blacklisted the connection will not happen, but
+                                       //the user will read this debug message "Autoconnecting to %s" that is misleading
+                                       logger(DEBUG_CONNECTIONS, LOG_INFO, "Autoconnecting to %s", n->name);
+                                       outgoing_t *outgoing = xzalloc(sizeof *outgoing);
+                                       outgoing->name = xstrdup(n->name);
+                                       list_insert_tail(mesh->outgoings, outgoing);
+                                       setup_outgoing_connection(mesh, outgoing);
+                               }
+                               break;
+                       }
+               }
+               if(nc > autoconnect) {
                        /* Too many active connections, try to remove one.
                           Choose a random outgoing connection to a node
                           that has at least one other connection.
@@ -217,8 +264,16 @@ static void periodic_handler(event_loop_t *loop, void *data) {
                if(nc >= autoconnect) {
                        /* If we have enough active connections,
                           remove any pending outgoing connections.
+                          Do not remove pending connections to unreachable
+                          nodes.
                        */
+                       node_t *o_node = NULL;
                        for list_each(outgoing_t, o, mesh->outgoings) {
+                               o_node = lookup_node(mesh, o->name);
+                               /* o_node is NULL if it is not part of the graph yet */
+                               if(!o_node || !o_node->status.reachable)
+                                       continue;
+
                                bool found = false;
                                for list_each(connection_t, c, mesh->connections) {
                                        if(c->outgoing == o) {
@@ -228,6 +283,10 @@ static void periodic_handler(event_loop_t *loop, void *data) {
                                }
                                if(!found) {
                                        logger(DEBUG_CONNECTIONS, LOG_INFO, "Cancelled outgoing connection to %s", o->name);
+                                       /* The node variable is leaked in from using the list_each macro.
+                                          The o variable could be used, but using node directly
+                                          is more efficient.
+                                       */
                                        list_delete_node(mesh->outgoings, node);
                                }
                        }