X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fgraph.c;h=5a0aab0ba7bd04979198492ef7ab3854b251484c;hp=c04cef40e01e48cc8fc67471e6c4c51a903a915f;hb=7ea85043ac1fb2096baea44f6b0af27ac0d0b2cf;hpb=f02d3ed3e135b5326003e7f69f8331ff6a3cc219

diff --git a/src/graph.c b/src/graph.c
index c04cef40..5a0aab0b 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -1,6 +1,6 @@
 /*
     graph.c -- graph algorithms
-    Copyright (C) 2001-2006 Guus Sliepen <guus@tinc-vpn.org>,
+    Copyright (C) 2001-2009 Guus Sliepen <guus@tinc-vpn.org>,
                   2001-2005 Ivo Timmermans
 
     This program is free software; you can redistribute it and/or modify
@@ -13,11 +13,9 @@
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-    $Id$
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
 /* We need to generate two trees from the graph:
@@ -46,7 +44,7 @@
 
 #include "system.h"
 
-#include "avl_tree.h"
+#include "splay_tree.h"
 #include "config.h"
 #include "connection.h"
 #include "device.h"
@@ -57,23 +55,19 @@
 #include "process.h"
 #include "subnet.h"
 #include "utils.h"
+#include "xalloc.h"
 
 /* Implementation of Kruskal's algorithm.
-   Running time: O(EN)
+   Running time: O(E)
    Please note that sorting on weight is already done by add_edge().
 */
 
 void mst_kruskal(void) {
-	avl_node_t *node, *next;
+	splay_node_t *node, *next;
 	edge_t *e;
 	node_t *n;
 	connection_t *c;
-	int nodes = 0;
-	int safe_edges = 0;
-	bool skipped;
 
-	cp();
-	
 	/* Clear MST status on connections */
 
 	for(node = connection_tree->head; node; node = node->next) {
@@ -81,11 +75,6 @@ void mst_kruskal(void) {
 		c->status.mst = false;
 	}
 
-	/* Do we have something to do at all? */
-
-	if(!edge_weight_tree->head)
-		return;
-
 	ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Running Kruskal's algorithm:");
 
 	/* Clear visited status on nodes */
@@ -93,29 +82,16 @@ void mst_kruskal(void) {
 	for(node = node_tree->head; node; node = node->next) {
 		n = node->data;
 		n->status.visited = false;
-		nodes++;
-	}
-
-	/* Starting point */
-
-	for(node = edge_weight_tree->head; node; node = node->next) {
-		e = node->data;
-		if(e->from->status.reachable) {
-			e->from->status.visited = true;
-			break;
-		}
 	}
 
 	/* Add safe edges */
 
-	for(skipped = false, node = edge_weight_tree->head; node; node = next) {
+	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) {
-			skipped = true;
+		if(!e->reverse || (e->from->status.visited && e->to->status.visited))
 			continue;
-		}
 
 		e->from->status.visited = true;
 		e->to->status.visited = true;
@@ -126,20 +102,133 @@ void mst_kruskal(void) {
 		if(e->reverse->connection)
 			e->reverse->connection->status.mst = true;
 
-		safe_edges++;
-
 		ifdebug(SCARY_THINGS) logger(LOG_DEBUG, " Adding edge %s - %s weight %d", e->from->name,
 				   e->to->name, e->weight);
+	}
+}
 
-		if(skipped) {
-			skipped = false;
-			next = edge_weight_tree->head;
-			continue;
+/* Implementation of Dijkstra's algorithm.
+   Running time: O(N^2)
+*/
+
+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:");
+
+	/* 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;
+		n->distance = -1;
+	}
+
+	/* Begin with myself */
+
+	myself->status.indirect = false;
+	myself->nexthop = myself;
+	myself->via = myself;
+	myself->distance = 0;
+	list_insert_head(todo_list, myself);
+
+	/* 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 e->reverse->address != n->address, then e->to is probably
+			     not reachable for the nodes left of n. We do as if the indirectdata
+			     flag is set on edge e.
+			   - 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(sockaddrcmp(&e->to->address, &e->address)) {
+				node = splay_unlink(node_udp_tree, e->to);
+				sockaddrfree(&e->to->address);
+				sockaddrcpy(&e->to->address, &e->address);
+
+				if(e->to->hostname)
+					free(e->to->hostname);
+
+				e->to->hostname = sockaddr2hostname(&e->to->address);
+
+				if(node)
+					splay_insert_node(node_udp_tree, node);
+
+				if(e->to->options & OPTION_PMTU_DISCOVERY) {
+					e->to->mtuprobes = 0;
+					e->to->minmtu = 0;
+					e->to->maxmtu = MTU;
+					if(e->to->status.validkey)
+						send_mtu_probe(e->to);
+				}
+			}
+
+			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);
 		}
 	}
 
-	ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Done, counted %d nodes and %d safe edges.", nodes,
-			   safe_edges);
+	list_free(todo_list);
 }
 
 /* Implementation of a simple breadth-first search algorithm.
@@ -147,18 +236,12 @@ void mst_kruskal(void) {
 */
 
 void sssp_bfs(void) {
-	avl_node_t *node, *next, *to;
+	splay_node_t *node, *to;
 	edge_t *e;
 	node_t *n;
 	list_t *todo_list;
 	list_node_t *from, *todonext;
 	bool indirect;
-	char *name;
-	char *address, *port;
-	char *envp[7];
-	int i;
-
-	cp();
 
 	todo_list = list_alloc(NULL);
 
@@ -222,27 +305,8 @@ void sssp_bfs(void) {
 			e->to->via = indirect ? n->via : e->to;
 			e->to->options = e->options;
 
-			if(sockaddrcmp(&e->to->address, &e->address)) {
-				node = avl_unlink(node_udp_tree, e->to);
-				sockaddrfree(&e->to->address);
-				sockaddrcpy(&e->to->address, &e->address);
-
-				if(e->to->hostname)
-					free(e->to->hostname);
-
-				e->to->hostname = sockaddr2hostname(&e->to->address);
-
-				if(node)
-					avl_insert_node(node_udp_tree, node);
-
-				if(e->to->options & OPTION_PMTU_DISCOVERY) {
-					e->to->mtuprobes = 0;
-					e->to->minmtu = 0;
-					e->to->maxmtu = MTU;
-					if(e->to->status.validkey)
-						send_mtu_probe(e->to);
-				}
-			}
+			if(e->to->address.sa.sa_family == AF_UNSPEC && e->address.sa.sa_family != AF_UNKNOWN)
+				update_node_udp(e->to, &e->address);
 
 			list_insert_tail(todo_list, e->to);
 		}
@@ -252,6 +316,15 @@ void sssp_bfs(void) {
 	}
 
 	list_free(todo_list);
+}
+
+void check_reachability() {
+	splay_node_t *node, *next;
+	node_t *n;
+	char *name;
+	char *address, *port;
+	char *envp[7];
+	int i;
 
 	/* Check reachability status. */
 
@@ -263,15 +336,15 @@ void sssp_bfs(void) {
 			n->status.reachable = !n->status.reachable;
 
 			if(n->status.reachable) {
-				ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Node %s (%s) became reachable"),
+				ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became reachable",
 					   n->name, n->hostname);
-				avl_insert(node_udp_tree, n);
 			} else {
-				ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Node %s (%s) became unreachable"),
+				ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became unreachable",
 					   n->name, n->hostname);
-				avl_delete(node_udp_tree, n);
 			}
 
+			/* TODO: only clear status.validkey if node is unreachable? */
+
 			n->status.validkey = false;
 			n->status.waitingforkey = false;
 
@@ -279,18 +352,20 @@ void sssp_bfs(void) {
 			n->minmtu = 0;
 			n->mtuprobes = 0;
 
-			asprintf(&envp[0], "NETNAME=%s", netname ? : "");
-			asprintf(&envp[1], "DEVICE=%s", device ? : "");
-			asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
-			asprintf(&envp[3], "NODE=%s", n->name);
+			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);
-			asprintf(&envp[4], "REMOTEADDRESS=%s", address);
-			asprintf(&envp[5], "REMOTEPORT=%s", port);
+			xasprintf(&envp[4], "REMOTEADDRESS=%s", address);
+			xasprintf(&envp[5], "REMOTEPORT=%s", port);
 			envp[6] = NULL;
 
 			execute_script(n->status.reachable ? "host-up" : "host-down", envp);
 
-			asprintf(&name,
+			xasprintf(&name,
 					 n->status.reachable ? "hosts/%s-up" : "hosts/%s-down",
 					 n->name);
 			execute_script(name, envp);
@@ -313,66 +388,39 @@ void sssp_bfs(void) {
    dot -Tpng graph_filename -o image_filename.png -Gconcentrate=true
 */
 
-static void dump_graph(int fd, short events, void *data) {
-	avl_node_t *node;
+int dump_graph(struct evbuffer *out) {
+	splay_node_t *node;
 	node_t *n;
 	edge_t *e;
-	char *filename = NULL, *tmpname = NULL;
-	FILE *file;
-	
-	if(!get_config_string(lookup_config(config_tree, "GraphDumpFile"), &filename))
-		return;
-
-	ifdebug(PROTOCOL) logger(LOG_NOTICE, "Dumping graph");
-	
-	if(filename[0] == '|') {
-		file = popen(filename + 1, "w");
-	} else {
-		asprintf(&tmpname, "%s.new", filename);
-		file = fopen(tmpname, "w");
-	}
 
-	if(!file) {
-		logger(LOG_ERR, "Unable to open graph dump file %s: %s", filename, strerror(errno));
-		free(tmpname);
-		return;
-	}
-
-	fprintf(file, "digraph {\n");
+	if(evbuffer_add_printf(out, "digraph {\n") == -1)
+		return errno;
 	
 	/* dump all nodes first */
 	for(node = node_tree->head; node; node = node->next) {
 		n = node->data;
-		fprintf(file, "	%s [label = \"%s\"];\n", n->name, n->name);
+		if(evbuffer_add_printf(out, "	%s [label = \"%s\"];\n",
+							   n->name, n->name) == -1)
+			return errno;
 	}
 
 	/* now dump all edges */
 	for(node = edge_weight_tree->head; node; node = node->next) {
 		e = node->data;
-		fprintf(file, "	%s -> %s;\n", e->from->name, e->to->name);
+		if(evbuffer_add_printf(out, "	%s -> %s;\n",
+							   e->from->name, e->to->name) == -1)
+			return errno;
 	}
 
-	fprintf(file, "}\n");	
-	
-	if(filename[0] == '|') {
-		pclose(file);
-	} else {
-		fclose(file);
-#ifdef HAVE_MINGW
-		unlink(filename);
-#endif
-		rename(tmpname, filename);
-		free(tmpname);
-	}
+	if(evbuffer_add_printf(out, "}\n") == -1)
+		return errno;
+
+	return 0;
 }
 
 void graph(void) {
-	static struct event ev;
-
-	sssp_bfs();
+    subnet_cache_flush();
+	sssp_dijkstra();
+	check_reachability();
 	mst_kruskal();
-
-	if(!timeout_initialized(&ev))
-		timeout_set(&ev, dump_graph, NULL);
-	event_add(&ev, &(struct timeval){5, 0});
 }