X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fgraph.c;h=5a0aab0ba7bd04979198492ef7ab3854b251484c;hb=7ea85043ac1fb2096baea44f6b0af27ac0d0b2cf;hp=c177347060786fdcc1f8ef574d7d3edc409c6c1b;hpb=9bab08e972ae0ca4b904a659d9aed46aaa9b5dd5;p=tinc

diff --git a/src/graph.c b/src/graph.c
index c1773470..5a0aab0b 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -1,7 +1,7 @@
 /*
     graph.c -- graph algorithms
-    Copyright (C) 2001-2003 Guus Sliepen <guus@sliepen.eu.org>,
-                  2001-2003 Ivo Timmermans <ivo@o2w.nl>
+    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
     it under the terms of the GNU General Public License as published by
@@ -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: graph.c,v 1.1.2.32 2003/12/20 21:09:33 guus Exp $
+    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 +44,8 @@
 
 #include "system.h"
 
-#include "avl_tree.h"
+#include "splay_tree.h"
+#include "config.h"
 #include "connection.h"
 #include "device.h"
 #include "edge.h"
@@ -54,25 +53,21 @@
 #include "netutl.h"
 #include "node.h"
 #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;
+void mst_kruskal(void) {
+	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) {
@@ -80,11 +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 */
@@ -92,23 +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 */
-
-	((edge_t *) edge_weight_tree->head->data)->from->status.visited = true;
-
 	/* 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;
@@ -119,41 +102,148 @@ 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.
    Running time: O(E)
 */
 
-void sssp_bfs(void)
-{
-	avl_node_t *node, *from, *next, *to;
+void sssp_bfs(void) {
+	splay_node_t *node, *to;
 	edge_t *e;
 	node_t *n;
-	avl_tree_t *todo_tree;
+	list_t *todo_list;
+	list_node_t *from, *todonext;
 	bool indirect;
-	char *name;
-	char *address, *port;
-	char *envp[7];
-	int i;
-
-	cp();
 
-	todo_tree = avl_alloc_tree(NULL, NULL);
+	todo_list = list_alloc(NULL);
 
 	/* Clear visited status on nodes */
 
@@ -169,86 +259,72 @@ void sssp_bfs(void)
 	myself->status.indirect = false;
 	myself->nexthop = myself;
 	myself->via = myself;
-	node = avl_alloc_node();
-	node->data = myself;
-	avl_insert_top(todo_tree, node);
-
-	/* Loop while todo_tree is filled */
-
-	while(todo_tree->head) {
-		for(from = todo_tree->head; from; from = next) {	/* "from" is the node from which we start */
-			next = from->next;
-			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)
-					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 and (re)add it to the todo_tree to (re)examine the reachability
-				     of nodes behind it.
-				 */
-
-				indirect = n->status.indirect || e->options & OPTION_INDIRECT
-					|| ((n != myself) && sockaddrcmp(&n->address, &e->reverse->address));
-
-				if(e->to->status.visited
-				   && (!e->to->status.indirect || indirect))
-					continue;
-
-				e->to->status.visited = true;
-				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 = 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);
-					avl_insert_node(node_udp_tree, node);
-
-					if(e->to->options & OPTION_DONTFRAGMENT) {
-						e->to->mtu = MTU;
-						e->to->mtuprobes = 0;
-						e->to->probedmtu = 0;
-						if(e->to->status.validkey)
-							send_mtu_probe(e->to);
-					}
-				}
+	list_insert_head(todo_list, myself);
 
-				node = avl_alloc_node();
-				node->data = e->to;
-				avl_insert_before(todo_tree, from, node);
-			}
+	/* 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;
 
-			avl_delete_node(todo_tree, from);
+		for(to = n->edge_tree->head; to; to = to->next) {	/* "to" is the edge connected to "from" */
+			e = to->data;
+
+			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 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 and (re)add it to the todo_list to (re)examine the reachability
+			     of nodes behind it.
+			 */
+
+			indirect = n->status.indirect || e->options & OPTION_INDIRECT
+				|| ((n != myself) && sockaddrcmp(&n->address, &e->reverse->address));
+
+			if(e->to->status.visited
+			   && (!e->to->status.indirect || indirect))
+				continue;
+
+			e->to->status.visited = true;
+			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);
+
+			list_insert_tail(todo_list, e->to);
 		}
+
+		todonext = from->next;
+		list_delete_node(todo_list, from);
 	}
 
-	avl_free_tree(todo_tree);
+	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. */
 
@@ -260,26 +336,36 @@ 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);
 			} 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);
 			}
 
+			/* TODO: only clear status.validkey if node is unreachable? */
+
 			n->status.validkey = false;
 			n->status.waitingforkey = false;
 
-			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);
+			n->maxmtu = MTU;
+			n->minmtu = 0;
+			n->mtuprobes = 0;
+
+			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;
 
-			asprintf(&name,
+			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);
@@ -288,14 +374,53 @@ void sssp_bfs(void)
 			free(address);
 			free(port);
 
-			for(i = 0; i < 7; i++)
+			for(i = 0; i < 6; i++)
 				free(envp[i]);
+
+			subnet_update(n, NULL, n->status.reachable);
 		}
 	}
 }
 
-void graph(void)
-{
+/* Dump nodes and edges to a graphviz file.
+	   
+   The file can be converted to an image with
+   dot -Tpng graph_filename -o image_filename.png -Gconcentrate=true
+*/
+
+int dump_graph(struct evbuffer *out) {
+	splay_node_t *node;
+	node_t *n;
+	edge_t *e;
+
+	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;
+		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;
+		if(evbuffer_add_printf(out, "	%s -> %s;\n",
+							   e->from->name, e->to->name) == -1)
+			return errno;
+	}
+
+	if(evbuffer_add_printf(out, "}\n") == -1)
+		return errno;
+
+	return 0;
+}
+
+void graph(void) {
+    subnet_cache_flush();
+	sssp_dijkstra();
+	check_reachability();
 	mst_kruskal();
-	sssp_bfs();
 }