/*
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 "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"
+#include "graph.h"
/* Implementation of Kruskal's algorithm.
Running time: O(E)
Please note that sorting on weight is already done by add_edge().
*/
-void mst_kruskal(void) {
+static void mst_kruskal(void) {
splay_node_t *node, *next;
edge_t *e;
node_t *n;
c->status.mst = false;
}
- 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 */
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,
+ logger(DEBUG_SCARY_THINGS, 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)
-*/
-
-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);
- }
- }
-
- list_free(todo_list);
-}
-
/* Implementation of a simple breadth-first search algorithm.
Running time: O(E)
*/
-void sssp_bfs(void) {
+static void sssp_bfs(void) {
splay_node_t *node, *to;
edge_t *e;
node_t *n;
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)
update_node_udp(e->to, &e->address);
list_free(todo_list);
}
-void check_reachability() {
+static void check_reachability(void) {
splay_node_t *node, *next;
node_t *n;
char *name;
n->status.reachable = !n->status.reachable;
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);
}
n->minmtu = 0;
n->mtuprobes = 0;
- event_del(&n->mtuevent);
+ if(timeout_initialized(&n->mtuevent))
+ event_del(&n->mtuevent);
xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
xasprintf(&envp[1], "DEVICE=%s", device ? : "");
void graph(void) {
subnet_cache_flush();
- sssp_dijkstra();
+ sssp_bfs();
check_reachability();
mst_kruskal();
}
projects / tinc / blobdiff