-void kruskal(void)
-{
- avl_node_t *node;
- edge_t *e;
- node_t *n;
- connection_t *c;
- int nodes;
- int safe_edges = 0;
-
- syslog(LOG_DEBUG, _("Running Kruskal's algorithm:"));
-
- /* Clear MST status on nodes */
-
- for(node = node_tree->head; node; node = node->next)
- {
- n = (node_t *)node->data;
- n->status.mst = 0;
- node++;
- }
-
- /* Clear MST status on connections */
-
- for(node = connection_tree->head; node; node = node->next)
- {
- c = (edge_t *)node->data;
- c->status.mst = 0;
- }
-
- /* Add safe edges */
-
- for(node = edge_weight_tree->head; node; node = node->next)
- {
-// Algorithm should work without this:
-// if(safe_edges = nodes - 1)
-// break;
-
- e = (edge_t *)node->data;
-
- if(e->from->status.mst && e->to->status.mst)
- continue;
-
- e->from->status.mst = 1;
- e->to->status.mst = 1;
- if(e->connection)
- e->connection->status.mst = 1;
-
- safe_edges++;
-
- syslog(LOG_DEBUG, _("Adding safe edge %s - %s weight %d"), e->from->name, e->to->name, e->weight);
- }
-
- syslog(LOG_DEBUG, _("Done."));
-
- if(safe_edges != nodes - 1)
- {
- syslog(LOG_ERR, _("Implementation of Kruskal's algorithm is screwed: %d nodes, found %d safe edges"), nodes, safe_edges);
- }
+static void mst_kruskal(meshlink_handle_t *mesh) {
+ /* Clear MST status on connections */
+
+ for list_each(connection_t, c, mesh->connections) {
+ c->status.mst = false;
+ }
+
+ logger(mesh, MESHLINK_DEBUG, "Running Kruskal's algorithm:");
+
+ /* Clear visited status on nodes */
+
+ for splay_each(node_t, n, mesh->nodes) {
+ n->status.visited = false;
+ }
+
+ /* Starting point */
+
+ for splay_each(edge_t, e, mesh->edges) {
+ if(e->from->status.reachable) {
+ e->from->status.visited = true;
+ break;
+ }
+ }
+
+ /* Add safe edges */
+
+ bool skipped = false;
+
+ for splay_each(edge_t, e, mesh->edges) {
+ if(!e->reverse || (e->from->status.visited == e->to->status.visited)) {
+ skipped = true;
+ continue;
+ }
+
+ e->from->status.visited = true;
+ e->to->status.visited = true;
+
+ if(e->connection) {
+ e->connection->status.mst = true;
+ }
+
+ if(e->reverse->connection) {
+ e->reverse->connection->status.mst = true;
+ }
+
+ logger(mesh, MESHLINK_DEBUG, " Adding edge %s - %s weight %d", e->from->name, e->to->name, e->weight);
+
+ if(skipped) {
+ skipped = false;
+ next = mesh->edges->head;
+ }
+ }
+}
+
+/* Implementation of a simple breadth-first search algorithm.
+ Running time: O(E)
+*/
+
+static void sssp_bfs(meshlink_handle_t *mesh) {
+ list_t *todo_list = list_alloc(NULL);
+
+ /* Clear visited status on nodes */
+
+ for splay_each(node_t, n, mesh->nodes) {
+ n->status.visited = false;
+ n->status.indirect = true;
+ n->distance = -1;
+ }
+
+ /* Begin with mesh->self */
+
+ mesh->self->status.visited = true;
+ mesh->self->status.indirect = false;
+ mesh->self->nexthop = mesh->self;
+ mesh->self->prevedge = NULL;
+ mesh->self->via = mesh->self;
+ mesh->self->distance = 0;
+ list_insert_head(todo_list, mesh->self);
+
+ /* Loop while todo_list is filled */
+
+ for list_each(node_t, n, todo_list) { /* "n" is the node from which we start */
+ logger(mesh, MESHLINK_DEBUG, " Examining edges from %s", n->name);
+
+ if(n->distance < 0) {
+ abort();
+ }
+
+ for splay_each(edge_t, e, n->edge_tree) { /* "e" is the edge connected to "from" */
+ if(!e->reverse) {
+ continue;
+ }
+
+ /* Situation:
+
+ /
+ /
+ ----->(n)---e-->(e->to)
+ \
+ \
+
+ Where e is an edge, (n) and (e->to) are nodes.
+ n->address is set to the e->address of the edge left of n to n.
+ We are currently examining the edge e right of n from n:
+
+ - If edge e provides for better reachability of e->to, update
+ e->to and (re)add it to the todo_list to (re)examine the reachability
+ of nodes behind it.
+ */
+
+ bool indirect = n->status.indirect || e->options & OPTION_INDIRECT;
+
+ if(e->to->status.visited
+ && (!e->to->status.indirect || indirect)
+ && (e->to->distance != n->distance + 1 || e->weight >= e->to->prevedge->weight)) {
+ continue;
+ }
+
+ e->to->status.visited = true;
+ e->to->status.indirect = indirect;
+ e->to->nexthop = (n->nexthop == mesh->self) ? e->to : n->nexthop;
+ e->to->prevedge = e;
+ e->to->via = indirect ? n->via : e->to;
+ e->to->options = e->options;
+ e->to->distance = n->distance + 1;
+
+ if(!e->to->status.reachable || (e->to->address.sa.sa_family == AF_UNSPEC && e->address.sa.sa_family != AF_UNKNOWN)) {
+ update_node_udp(mesh, e->to, &e->address);
+ }
+
+ list_insert_tail(todo_list, e->to);
+ }
+
+ next = node->next; /* Because the list_insert_tail() above could have added something extra for us! */
+ list_delete_node(todo_list, node);
+ }
+
+ list_free(todo_list);
+}
+
+static void check_reachability(meshlink_handle_t *mesh) {
+ /* Check reachability status. */
+
+ for splay_each(node_t, n, mesh->nodes) {
+ if(n->status.visited != n->status.reachable) {
+ n->status.reachable = !n->status.reachable;
+ n->last_state_change = mesh->loop.now.tv_sec;
+
+ 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);
+ }
+
+ /* TODO: only clear status.validkey if node is unreachable? */
+
+ 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.blacklisted) {
+ update_node_status(mesh, n);
+ }
+
+ if(!n->status.reachable) {
+ update_node_udp(mesh, n, NULL);
+ n->status.broadcast = false;
+ n->options = 0;
+ } else if(n->connection) {
+ if(n->connection->outgoing) {
+ send_req_key(mesh, n);
+ }
+ }
+
+ if(n->utcp) {
+ utcp_offline(n->utcp, !n->status.reachable);
+ }
+ }
+ }
+}
+
+void graph(meshlink_handle_t *mesh) {
+ sssp_bfs(mesh);
+ check_reachability(mesh);
+ mst_kruskal(mesh);