X-Git-Url: http://git.meshlink.io/?p=meshlink;a=blobdiff_plain;f=src%2Fgraph.c;h=b0e0b77a198a408cd2d88aecb2c4debde09022d3;hp=1725241157b435f7a6a78c9686004ac5d8f03e7e;hb=963c5055505f2fc117cd5efa06eaa02c9b2bf85d;hpb=8b1ad6f76f821648079818f6ff018bbc33b9d9e9

diff --git a/src/graph.c b/src/graph.c
index 17252411..b0e0b77a 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -1,7 +1,6 @@
 /*
     graph.c -- graph algorithms
-    Copyright (C) 2001-2011 Guus Sliepen <guus@tinc-vpn.org>,
-                  2001-2005 Ivo Timmermans
+    Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -37,230 +36,69 @@
    For the SSSP algorithm Dijkstra's seems to be a nice choice. Currently a
    simple breadth-first search is presented here.
 
-   The SSSP algorithm will also be used to determine whether nodes are directly,
-   indirectly or not reachable from the source. It will also set the correct
-   destination address and port of a node if possible.
+   The SSSP algorithm will also be used to determine whether nodes are
+   reachable from the source. It will also set the correct destination address
+   and port of a node if possible.
 */
 
 #include "system.h"
 
-#include "splay_tree.h"
-#include "config.h"
 #include "connection.h"
-#include "device.h"
 #include "edge.h"
 #include "graph.h"
+#include "list.h"
 #include "logger.h"
+#include "meshlink_internal.h"
 #include "netutl.h"
 #include "node.h"
-#include "process.h"
 #include "protocol.h"
-#include "subnet.h"
 #include "utils.h"
 #include "xalloc.h"
 #include "graph.h"
 
-/* Implementation of Kruskal's algorithm.
+/* Implementation of a simple breadth-first search algorithm.
    Running time: O(E)
-   Please note that sorting on weight is already done by add_edge().
-*/
-
-static void mst_kruskal(void) {
-	splay_node_t *node, *next;
-	edge_t *e;
-	node_t *n;
-	connection_t *c;
-
-	/* Clear MST status on connections */
-
-	for(node = connection_tree->head; node; node = node->next) {
-		c = node->data;
-		c->status.mst = false;
-	}
-
-	ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Running Kruskal's algorithm:");
-
-	/* Clear visited status on nodes */
-
-	for(node = node_tree->head; node; node = node->next) {
-		n = node->data;
-		n->status.visited = false;
-	}
-
-	/* Add safe edges */
-
-	for(node = edge_weight_tree->head; node; node = next) {
-		next = node->next;
-		e = node->data;
-
-		if(!e->reverse || (e->from->status.visited && e->to->status.visited))
-			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;
-
-		ifdebug(SCARY_THINGS) logger(LOG_DEBUG, " Adding edge %s - %s weight %d", e->from->name,
-				   e->to->name, e->weight);
-	}
-}
-
-/* Implementation of Dijkstra's algorithm.
-   Running time: O(N^2)
 */
 
-static void sssp_dijkstra(void) {
-	splay_node_t *node, *to;
-	edge_t *e;
-	node_t *n, *m;
-	list_t *todo_list;
-	list_node_t *lnode, *nnode;
-	bool indirect;
-
-	todo_list = list_alloc(NULL);
-
-	ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Running Dijkstra's algorithm:");
+static void sssp_bfs(meshlink_handle_t *mesh) {
+	list_t *todo_list = list_alloc(NULL);
 
 	/* Clear visited status on nodes */
 
-	for(node = node_tree->head; node; node = node->next) {
-		n = node->data;
+	for splay_each(node_t, n, mesh->nodes) {
 		n->status.visited = false;
-		n->status.indirect = true;
 		n->distance = -1;
 	}
 
-	/* Begin with myself */
+	/* Begin with mesh->self */
 
-	myself->status.indirect = false;
-	myself->nexthop = myself;
-	myself->via = myself;
-	myself->distance = 0;
-	list_insert_head(todo_list, myself);
+	mesh->self->status.visited = mesh->threadstarted;
+	mesh->self->nexthop = mesh->self;
+	mesh->self->prevedge = NULL;
+	mesh->self->distance = 0;
+	list_insert_head(todo_list, mesh->self);
 
 	/* Loop while todo_list is filled */
 
-	while(todo_list->head) {
-		n = NULL;
-		nnode = NULL;
-
-		/* Select node from todo_list with smallest distance */
-
-		for(lnode = todo_list->head; lnode; lnode = lnode->next) {
-			m = lnode->data;
-			if(!n || m->status.indirect < n->status.indirect || m->distance < n->distance) {
-				n = m;
-				nnode = lnode;
-			}
-		}
-
-		/* Mark this node as visited and remove it from the todo_list */
-
-		n->status.visited = true;
-		list_unlink_node(todo_list, nnode);
-
-		/* Update distance of neighbours and add them to the todo_list */
-
-		for(to = n->edge_tree->head; to; to = to->next) {	/* "to" is the edge connected to "from" */
-			e = to->data;
-
-			if(e->to->status.visited || !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.
-			 */
-
-			if(e->to->distance < 0)
-				list_insert_tail(todo_list, e->to);
-
-			indirect = n->status.indirect || e->options & OPTION_INDIRECT || ((n != myself) && sockaddrcmp(&n->address, &e->reverse->address));
-
-			if(e->to->distance >= 0 && (!e->to->status.indirect || indirect) && e->to->distance <= n->distance + e->weight)
-				continue;
-
-			e->to->distance = n->distance + e->weight;
-			e->to->status.indirect = indirect;
-			e->to->nexthop = (n->nexthop == myself) ? e->to : n->nexthop;
-			e->to->via = indirect ? n->via : e->to;
-			e->to->options = e->options;
-
-			if(e->to->address.sa.sa_family == AF_UNSPEC && e->address.sa.sa_family != AF_UNKNOWN)
-				update_node_udp(e->to, &e->address);
+	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);
 
-			ifdebug(SCARY_THINGS) logger(LOG_DEBUG, " Updating edge %s - %s weight %d distance %d", e->from->name,
-					   e->to->name, e->weight, e->to->distance);
+		if(n->distance < 0) {
+			abort();
 		}
-	}
-
-	list_free(todo_list);
-}
-
-/* Implementation of a simple breadth-first search algorithm.
-   Running time: O(E)
-*/
-
-static void sssp_bfs(void) {
-	splay_node_t *node, *to;
-	edge_t *e;
-	node_t *n;
-	list_t *todo_list;
-	list_node_t *from, *todonext;
-	bool indirect;
-
-	todo_list = list_alloc(NULL);
-
-	/* Clear visited status on nodes */
-
-	for(node = node_tree->head; node; node = node->next) {
-		n = node->data;
-		n->status.visited = false;
-		n->status.indirect = true;
-	}
-
-	/* Begin with myself */
-
-	myself->status.visited = true;
-	myself->status.indirect = false;
-	myself->nexthop = myself;
-	myself->prevedge = NULL;
-	myself->via = myself;
-	list_insert_head(todo_list, myself);
-
-	/* Loop while todo_list is filled */
-
-	for(from = todo_list->head; from; from = todonext) {	/* "from" is the node from which we start */
-		n = from->data;
-
-		for(to = n->edge_tree->head; to; to = to->next) {	/* "to" is the edge connected to "from" */
-			e = to->data;
 
-			if(!e->reverse)
+		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.
@@ -271,105 +109,137 @@ static void sssp_bfs(void) {
 			     of nodes behind it.
 			 */
 
-			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 == myself) ? e->to : n->nexthop;
+			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->address.sa.sa_family == AF_UNSPEC && e->address.sa.sa_family != AF_UNKNOWN)
-				update_node_udp(e->to, &e->address);
+			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);
 		}
 
-		todonext = from->next;
-		list_delete_node(todo_list, from);
+		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(void) {
-	splay_node_t *node, *next;
-	node_t *n;
-	char *name;
-	char *address, *port;
-	char *envp[7];
-	int i;
-
+static void check_reachability(meshlink_handle_t *mesh) {
 	/* Check reachability status. */
 
-	for(node = node_tree->head; node; node = next) {
-		next = node->next;
-		n = node->data;
+	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;
+
+			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;
-
-			if(n->status.reachable) {
-				ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became reachable",
-					   n->name, n->hostname);
-			} else {
-				ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became unreachable",
-					   n->name, n->hostname);
+			n->status.dirty = true;
+
+			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? */
 
 			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;
 
-			if(timeout_initialized(&n->mtuevent))
-				event_del(&n->mtuevent);
-
-			xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
-			xasprintf(&envp[1], "DEVICE=%s", device ? : "");
-			xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
-			xasprintf(&envp[3], "NODE=%s", n->name);
-			sockaddr2str(&n->address, &address, &port);
-			xasprintf(&envp[4], "REMOTEADDRESS=%s", address);
-			xasprintf(&envp[5], "REMOTEPORT=%s", port);
-			envp[6] = NULL;
+			timeout_del(&mesh->loop, &n->mtutimeout);
 
-			execute_script(n->status.reachable ? "host-up" : "host-down", envp);
-
-			xasprintf(&name,
-					 n->status.reachable ? "hosts/%s-up" : "hosts/%s-down",
-					 n->name);
-			execute_script(name, envp);
+			if(!n->status.blacklisted) {
+				update_node_status(mesh, n);
+			}
 
-			free(name);
-			free(address);
-			free(port);
+			if(!n->status.reachable) {
+				update_node_udp(mesh, n, NULL);
+				n->status.broadcast = false;
+			} else if(n->connection) {
+				if(n->connection->status.initiator) {
+					send_req_key(mesh, n);
+				}
+			}
 
-			for(i = 0; i < 6; i++)
-				free(envp[i]);
+			if(n->utcp) {
+				utcp_offline(n->utcp, !n->status.reachable);
+			}
+		}
+	}
 
-			subnet_update(n, NULL, n->status.reachable);
+	if(mesh->reachable != reachable) {
+		if(!reachable) {
+			mesh->last_unreachable = mesh->loop.now.tv_sec;
 
-			if(!n->status.reachable)
-				update_node_udp(n, NULL);
-			else if(n->connection)
-				send_ans_key(n);
+			if(mesh->threadstarted) {
+				timeout_set(&mesh->loop, &mesh->periodictimer, &(struct timespec) {
+					0, prng(mesh, TIMER_FUDGE)
+				});
+			}
 		}
+
+		mesh->reachable = reachable;
 	}
 }
 
-void graph(void) {
-	subnet_cache_flush();
-	sssp_bfs();
-	check_reachability();
-	mst_kruskal();
+void graph(meshlink_handle_t *mesh) {
+	sssp_bfs(mesh);
+	check_reachability(mesh);
 }