/*
graph.c -- graph algorithms
- Copyright (C) 2001-2010 Guus Sliepen <guus@tinc-vpn.org>,
+ Copyright (C) 2001-2012 Guus Sliepen <guus@tinc-vpn.org>,
2001-2005 Ivo Timmermans
This program is free software; you can redistribute it and/or modify
#include "system.h"
-#include "avl_tree.h"
+#include "splay_tree.h"
#include "config.h"
#include "connection.h"
#include "device.h"
#include "edge.h"
+#include "graph.h"
#include "logger.h"
#include "netutl.h"
#include "node.h"
#include "subnet.h"
#include "utils.h"
#include "xalloc.h"
-
-static bool graph_changed = true;
+#include "graph.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;
+static 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;
/* Clear MST status on connections */
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:");
+ logger(DEBUG_SCARY_THINGS, 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;
- 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;
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,
+ logger(DEBUG_SCARY_THINGS, 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;
- }
}
-
- ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Done, counted %d nodes and %d safe edges.", nodes,
- safe_edges);
}
/* Implementation of a simple breadth-first search algorithm.
Running time: O(E)
*/
-void sssp_bfs(void) {
- avl_node_t *node, *next, *to;
+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;
- char *name;
- char *address, *port;
- char *envp[7];
- int i;
todo_list = list_alloc(NULL);
n = node->data;
n->status.visited = false;
n->status.indirect = true;
+ n->distance = -1;
}
/* Begin with myself */
myself->status.visited = true;
myself->status.indirect = false;
myself->nexthop = myself;
+ myself->prevedge = NULL;
myself->via = myself;
+ myself->distance = 0;
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;
+ if(n->distance < 0)
+ abort();
for(to = n->edge_tree->head; to; to = to->next) { /* "to" is the edge connected to "from" */
e = to->data;
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));
+ indirect = n->status.indirect || e->options & OPTION_INDIRECT;
if(e->to->status.visited
- && (!e->to->status.indirect || indirect))
+ && (!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->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)
+ if(!e->to->status.reachable || (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);
}
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;
/* Check reachability status. */
if(n->status.visited != n->status.reachable) {
n->status.reachable = !n->status.reachable;
+ n->last_state_change = time(NULL);
if(n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became reachable",
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Node %s (%s) became reachable",
n->name, n->hostname);
} else {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became unreachable",
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Node %s (%s) became unreachable",
n->name, n->hostname);
}
+ if(experimental && OPTION_VERSION(n->options) >= 2)
+ n->status.sptps = true;
+
/* TODO: only clear status.validkey if node is unreachable? */
n->status.validkey = false;
n->minmtu = 0;
n->mtuprobes = 0;
- if(n->mtuevent) {
- event_del(n->mtuevent);
- n->mtuevent = NULL;
- }
+ if(timeout_initialized(&n->mtuevent))
+ event_del(&n->mtuevent);
xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
xasprintf(&envp[1], "DEVICE=%s", device ? : "");
subnet_update(n, NULL, n->status.reachable);
- if(!n->status.reachable)
+ if(!n->status.reachable) {
update_node_udp(n, NULL);
- else if(n->connection)
- send_ans_key(n);
+ } else if(n->connection) {
+ if(n->status.sptps) {
+ if(n->connection->outgoing)
+ send_req_key(n);
+ } else {
+ send_ans_key(n);
+ }
+ }
}
}
}
void graph(void) {
subnet_cache_flush();
sssp_bfs();
+ check_reachability();
mst_kruskal();
- graph_changed = true;
-}
-
-
-
-/* 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
-*/
-
-void dump_graph(void) {
- avl_node_t *node;
- node_t *n;
- edge_t *e;
- char *filename = NULL, *tmpname = NULL;
- FILE *file;
-
- if(!graph_changed || !get_config_string(lookup_config(config_tree, "GraphDumpFile"), &filename))
- return;
-
- graph_changed = false;
-
- ifdebug(PROTOCOL) logger(LOG_NOTICE, "Dumping graph");
-
- if(filename[0] == '|') {
- file = popen(filename + 1, "w");
- } else {
- xasprintf(&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");
-
- /* 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);
- }
-
- /* 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);
- }
-
- fprintf(file, "}\n");
-
- if(filename[0] == '|') {
- pclose(file);
- } else {
- fclose(file);
-#ifdef HAVE_MINGW
- unlink(filename);
-#endif
- rename(tmpname, filename);
- free(tmpname);
- }
}