#include "system.h"
-#include "avl_tree.h"
+#include "splay_tree.h"
#include "config.h"
#include "connection.h"
#include "device.h"
#include "subnet.h"
#include "utils.h"
-static bool graph_changed = true;
-
/* 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();
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 */
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,
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;
+
+ cp();
+
+ 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, *next, *to;
+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;
cp();
}
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. */
}
}
-void graph(void)
-{
- subnet_cache_flush();
- sssp_bfs();
- 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;
+int dump_graph(struct evbuffer *out) {
+ splay_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 {
- 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) {
+ subnet_cache_flush();
+ sssp_dijkstra();
+ check_reachability();
+ mst_kruskal();
}
projects / tinc / blobdiff