/*
graph.c -- graph algorithms
- Copyright (C) 2001-2009 Guus Sliepen <guus@tinc-vpn.org>,
+ Copyright (C) 2001-2013 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 "config.h"
#include "connection.h"
#include "device.h"
#include "edge.h"
+#include "graph.h"
+#include "list.h"
#include "logger.h"
+#include "names.h"
#include "netutl.h"
#include "node.h"
-#include "process.h"
+#include "protocol.h"
+#include "script.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)
Please note that sorting on weight is already done by add_edge().
*/
-void mst_kruskal(void) {
- avl_node_t *node, *next;
- edge_t *e;
- node_t *n;
- connection_t *c;
- int nodes = 0;
- int safe_edges = 0;
- bool skipped;
-
+static void mst_kruskal(void) {
/* Clear MST status on connections */
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
+ for list_each(connection_t, c, connection_list)
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;
+ for splay_each(node_t, n, node_tree)
n->status.visited = false;
- nodes++;
- }
/* Starting point */
- for(node = edge_weight_tree->head; node; node = node->next) {
- e = node->data;
+ for splay_each(edge_t, e, edge_weight_tree) {
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) {
- next = node->next;
- e = node->data;
+ bool skipped = false;
- if(!e->reverse || e->from->status.visited == e->to->status.visited) {
+ for splay_each(edge_t, e, edge_weight_tree) {
+ if(!e->reverse || (e->from->status.visited == e->to->status.visited)) {
skipped = true;
continue;
}
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);
+ 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;
- 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);
+static void sssp_bfs(void) {
+ list_t *todo_list = list_alloc(NULL);
/* Clear visited status on nodes */
- for(node = node_tree->head; node; node = node->next) {
- n = node->data;
+ for splay_each(node_t, n, node_tree) {
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;
+ for list_each(node_t, n, todo_list) { /* "n" is the node from which we start */
+ logger(DEBUG_SCARY_THINGS, LOG_DEBUG, " Examining edges from %s", n->name);
- for(to = n->edge_tree->head; to; to = to->next) { /* "to" is the edge connected to "from" */
- e = to->data;
+ if(n->distance < 0)
+ abort();
- if(!e->reverse)
+ for splay_each(edge_t, e, n->edge_tree) { /* "e" is the edge connected to "from" */
+ if(!e->reverse || e->to == myself)
continue;
/* Situation:
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));
+ bool 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;
+ // Only update nexthop if it doesn't increase the path length
+
+ if(!e->to->status.visited || (e->to->distance == n->distance + 1 && e->weight >= e->to->prevedge->weight))
+ e->to->nexthop = (n->nexthop == myself) ? e->to : n->nexthop;
+
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);
}
- todonext = from->next;
- list_delete_node(todo_list, from);
+ next = node->next; /* Because the list_insert_tail() above could have added something extra for us! */
+ list_delete_node(todo_list, node);
}
list_free(todo_list);
+}
+static void check_reachability(void) {
/* Check reachability status. */
- for(node = node_tree->head; node; node = next) {
- next = node->next;
- n = node->data;
-
+ int reachable_count = 0;
+ int became_reachable_count = 0;
+ int became_unreachable_count = 0;
+ for splay_each(node_t, n, node_tree) {
if(n->status.visited != n->status.reachable) {
n->status.reachable = !n->status.reachable;
+ n->last_state_change = now.tv_sec;
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);
+ if (n != myself)
+ became_reachable_count++;
} 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 (n != myself)
+ became_unreachable_count++;
}
+ if(experimental && OPTION_VERSION(n->options) >= 2)
+ n->status.sptps = true;
+
/* TODO: only clear status.validkey if node is unreachable? */
n->status.validkey = false;
+ if(n->status.sptps) {
+ sptps_stop(&n->sptps);
+ n->status.waitingforkey = false;
+ }
n->last_req_key = 0;
+ n->status.udp_confirmed = false;
n->maxmtu = MTU;
+ n->maxrecentlen = 0;
n->minmtu = 0;
n->mtuprobes = 0;
- if(n->mtuevent) {
- event_del(n->mtuevent);
- n->mtuevent = NULL;
- }
+ timeout_del(&n->udp_ping_timeout);
+
+ char *name;
+ char *address;
+ char *port;
+ char *envp[8] = {NULL};
xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
xasprintf(&envp[1], "DEVICE=%s", device ? : "");
sockaddr2str(&n->address, &address, &port);
xasprintf(&envp[4], "REMOTEADDRESS=%s", address);
xasprintf(&envp[5], "REMOTEPORT=%s", port);
- envp[6] = NULL;
+ xasprintf(&envp[6], "NAME=%s", myself->name);
execute_script(n->status.reachable ? "host-up" : "host-down", envp);
- xasprintf(&name,
- n->status.reachable ? "hosts/%s-up" : "hosts/%s-down",
- n->name);
+ xasprintf(&name, n->status.reachable ? "hosts/%s-up" : "hosts/%s-down", n->name);
execute_script(name, envp);
free(name);
free(address);
free(port);
- for(i = 0; i < 6; i++)
+ for(int i = 0; i < 7; i++)
free(envp[i]);
subnet_update(n, NULL, n->status.reachable);
- if(!n->status.reachable)
+ if(!n->status.reachable) {
update_node_udp(n, NULL);
+ memset(&n->status, 0, sizeof n->status);
+ n->options = 0;
+ } else if(n->connection) {
+ // Speed up UDP probing by sending our key.
+ if(!n->status.sptps)
+ send_ans_key(n);
+ }
}
+
+ if(n->status.reachable && n != myself)
+ reachable_count++;
+ }
+
+ if (device_standby) {
+ if (reachable_count == 0 && became_unreachable_count > 0)
+ device_disable();
+ else if (reachable_count > 0 && reachable_count == became_reachable_count)
+ device_enable();
}
}
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);
- }
}
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