/*
graph.c -- graph algorithms
- Copyright (C) 2001-2002 Guus Sliepen <guus@sliepen.warande.net>,
- 2001-2002 Ivo Timmermans <itimmermans@bigfoot.com>
+ 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
it under the terms of the GNU General Public License as published by
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 1.1.2.6 2002/02/10 21:57:54 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:
destination address and port of a node if possible.
*/
-#include <syslog.h>
-#include "config.h"
-#include <string.h>
-#if defined(HAVE_FREEBSD) || defined(HAVE_OPENBSD)
- #include <sys/param.h>
-#endif
-#include <netinet/in.h>
-
-#include <avl_tree.h>
-#include <utils.h>
+#include "system.h"
+#include "avl_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 "edge.h"
-#include "connection.h"
+#include "process.h"
+#include "protocol.h"
+#include "subnet.h"
+#include "utils.h"
+#include "xalloc.h"
-#include "system.h"
+static bool graph_changed = true;
/* 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;
- int skipped;
-
- /* Do we have something to do at all? */
-
- if(!edge_weight_tree->head)
- return;
-
- /* Clear visited status on nodes */
-
- for(node = node_tree->head; node; node = node->next)
- {
- n = (node_t *)node->data;
- n->status.visited = 0;
- nodes++;
- }
-
- /* Starting point */
-
- ((edge_t *)edge_weight_tree->head->data)->from.node->status.visited = 1;
-
- /* Clear MST status on connections */
-
- for(node = connection_tree->head; node; node = node->next)
- {
- c = (connection_t *)node->data;
- c->status.mst = 0;
- }
-
- /* Add safe edges */
-
- for(skipped = 0, node = edge_weight_tree->head; node; node = next)
- {
- next = node->next;
- e = (edge_t *)node->data;
-
- if(e->from.node->status.visited == e->to.node->status.visited)
- {
- skipped = 1;
- continue;
- }
-
- e->from.node->status.visited = 1;
- e->to.node->status.visited = 1;
- if(e->connection)
- e->connection->status.mst = 1;
-
- safe_edges++;
-
- if(skipped)
- {
- next = edge_weight_tree->head;
- continue;
- }
- }
+static 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;
+
+ /* Clear MST status on connections */
+
+ for(node = connection_tree->head; node; node = node->next) {
+ c = node->data;
+ 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) {
+ next = node->next;
+ e = node->data;
+
+ if(!e->reverse || e->from->status.visited == e->to->status.visited) {
+ skipped = true;
+ continue;
+ }
+
+ e->from->status.visited = true;
+ e->to->status.visited = true;
+
+ if(e->connection)
+ e->connection->status.mst = 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;
+ }
+ }
+
+ 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, *from, *next, *to;
- edge_t *e;
- node_t *n;
- halfconnection_t to_hc, from_hc;
- avl_tree_t *todo_tree;
-
- todo_tree = avl_alloc_tree(NULL, NULL);
-
- /* Clear visited status on nodes */
-
- for(node = node_tree->head; node; node = node->next)
- {
- n = (node_t *)node->data;
- n->status.visited = 0;
- }
-
- /* Begin with myself */
-
- myself->status.visited = 1;
- 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 = (node_t *)from->data;
-
- for(to = n->edge_tree->head; to; to = to->next) /* "to" is the edge connected to "from" */
- {
- e = (edge_t *)to->data;
-
- if(e->from.node == n) /* "from_hc" is the halfconnection with .node == from */
- to_hc = e->to, from_hc = e->from;
- else
- to_hc = e->from, from_hc = e->to;
-
- if(!to_hc.node->status.visited)
- {
- to_hc.node->status.visited = 1;
- to_hc.node->nexthop = (n->nexthop == myself) ? to_hc.node : n->nexthop;
- to_hc.node->via = (e->options & OPTION_INDIRECT || n->via != n) ? n->via : to_hc.node;
- to_hc.node->options = e->options;
- if(to_hc.node->address != to_hc.address || to_hc.node->port != to_hc.port)
- {
- node = avl_unlink(node_udp_tree, to_hc.node);
- to_hc.node->address = to_hc.address;
- to_hc.node->port = to_hc.port;
- if(to_hc.node->hostname)
- free(to_hc.node->hostname);
- to_hc.node->hostname = hostlookup(htonl(to_hc.address));
- avl_insert_node(node_udp_tree, node);
- }
- to_hc.node->port = to_hc.port;
- node = avl_alloc_node();
- node->data = to_hc.node;
- avl_insert_before(todo_tree, from, node);
- }
- }
-
- avl_delete_node(todo_tree, from);
- }
- }
-
- avl_free_tree(todo_tree);
-
- /* Check reachability status. */
-
- for(node = node_tree->head; node; node = next)
- {
- next = node->next;
- n = (node_t *)node->data;
-
- if(n->status.visited)
- {
- if(!n->status.reachable)
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_DEBUG, _("Node %s (%s) became reachable"), n->name, n->hostname);
- n->status.reachable = 1;
+static 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);
+
+ /* 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;
}
- }
- else
- {
- if(n->status.reachable)
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_DEBUG, _("Node %s (%s) became unreachable"), n->name, n->hostname);
- n->status.reachable = 0;
- n->status.validkey = 0;
- n->status.waitingforkey = 0;
- n->sent_seqno = 0;
+
+ /* Begin with myself */
+
+ myself->status.visited = true;
+ myself->status.indirect = false;
+ myself->nexthop = myself;
+ myself->prevedge = NULL;
+ myself->via = myself;
+ 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(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 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;
+
+ 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->prevedge = e;
+ 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);
}
- }
- }
+
+ list_free(todo_list);
+
+ /* Check reachability status. */
+
+ for(node = node_tree->head; node; node = next) {
+ next = node->next;
+ n = node->data;
+
+ if(n->status.visited != n->status.reachable) {
+ n->status.reachable = !n->status.reachable;
+
+ if(n->status.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",
+ n->name, n->hostname);
+ }
+
+ /* TODO: only clear status.validkey if node is unreachable? */
+
+ n->status.validkey = false;
+ n->last_req_key = 0;
+
+ n->maxmtu = MTU;
+ n->minmtu = 0;
+ n->mtuprobes = 0;
+
+ if(n->mtuevent) {
+ event_del(n->mtuevent);
+ n->mtuevent = NULL;
+ }
+
+ 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);
+ xasprintf(&envp[4], "REMOTEADDRESS=%s", address);
+ xasprintf(&envp[5], "REMOTEPORT=%s", port);
+ envp[6] = NULL;
+
+ 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);
+
+ free(name);
+ free(address);
+ free(port);
+
+ for(i = 0; i < 6; i++)
+ free(envp[i]);
+
+ subnet_update(n, NULL, 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) {
+ send_ans_key(n);
+ }
+ }
+ }
+}
+
+void graph(void) {
+ subnet_cache_flush();
+ sssp_bfs();
+ mst_kruskal();
+ graph_changed = true;
}
-void graph(void)
-{
- mst_kruskal();
- sssp_bfs();
+
+
+/* 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, *pipe = NULL;
+
+ 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 = pipe = 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(pipe) {
+ pclose(pipe);
+ } else {
+ fclose(file);
+#ifdef HAVE_MINGW
+ unlink(filename);
+#endif
+ rename(tmpname, filename);
+ free(tmpname);
+ }
}
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