/*
graph.c -- graph algorithms
- Copyright (C) 2001-2003 Guus Sliepen <guus@sliepen.eu.org>,
- 2001-2003 Ivo Timmermans <ivo@o2w.nl>
+ Copyright (C) 2001-2014 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 1.1.2.34 2003/12/22 11:04:16 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:
#include "system.h"
#include "avl_tree.h"
+#include "conf.h"
#include "connection.h"
#include "device.h"
#include "edge.h"
+#include "graph.h"
#include "logger.h"
#include "netutl.h"
#include "node.h"
#include "process.h"
+#include "protocol.h"
+#include "subnet.h"
#include "utils.h"
+#include "xalloc.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)
-{
+static void mst_kruskal(void) {
avl_node_t *node, *next;
edge_t *e;
node_t *n;
int safe_edges = 0;
bool skipped;
- cp();
-
/* Clear MST status on connections */
for(node = connection_tree->head; node; node = node->next) {
/* Do we have something to do at all? */
- if(!edge_weight_tree->head)
+ if(!edge_weight_tree->head) {
return;
+ }
ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Running Kruskal's algorithm:");
/* Starting point */
- ((edge_t *) edge_weight_tree->head->data)->from->status.visited = true;
+ 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 */
e->from->status.visited = true;
e->to->status.visited = true;
- if(e->connection)
+ if(e->connection) {
e->connection->status.mst = true;
+ }
- if(e->reverse->connection)
+ 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);
+ e->to->name, e->weight);
if(skipped) {
skipped = false;
}
ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Done, counted %d nodes and %d safe edges.", nodes,
- safe_edges);
+ 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;
+static void sssp_bfs(void) {
+ avl_node_t *node, *next, *to;
edge_t *e;
node_t *n;
- avl_tree_t *todo_tree;
+ list_t *todo_list;
+ list_node_t *from, *todonext;
bool indirect;
char *name;
char *address, *port;
- char *envp[7];
+ char *envp[8] = {NULL};
int i;
- cp();
-
- todo_tree = avl_alloc_tree(NULL, NULL);
+ todo_list = list_alloc(NULL);
/* Clear visited status on nodes */
myself->status.visited = true;
myself->status.indirect = false;
myself->nexthop = myself;
+ myself->prevedge = NULL;
myself->via = myself;
- node = avl_alloc_node();
- node->data = myself;
- avl_insert_top(todo_tree, node);
+ list_insert_head(todo_list, myself);
- /* Loop while todo_tree is filled */
+ /* Loop while todo_list 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 = from->data;
+ 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;
+ for(to = n->edge_tree->head; to; to = to->next) { /* "to" is the edge connected to "from" */
+ e = to->data;
+
+ if(!e->reverse) {
+ continue;
+ }
- if(!e->reverse)
- continue;
+ /* Situation:
- /* Situation:
+ /
+ /
+ ----->(n)---e-->(e->to)
+ \
+ \
- /
- /
- ----->(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:
- 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.
+ */
- - 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_tree to (re)examine the reachability
- of nodes behind it.
- */
+ indirect = n->status.indirect || e->options & OPTION_INDIRECT;
- indirect = n->status.indirect || e->options & OPTION_INDIRECT
- || ((n != myself) && sockaddrcmp(&n->address, &e->reverse->address));
+ if(e->to->status.visited
+ && (!e->to->status.indirect || indirect)) {
+ continue;
+ }
- if(e->to->status.visited
- && (!e->to->status.indirect || indirect))
- continue;
+ // Only update nexthop the first time we visit this node.
- e->to->status.visited = true;
- e->to->status.indirect = indirect;
+ if(!e->to->status.visited) {
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 = avl_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);
- avl_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);
- }
- }
-
- node = avl_alloc_node();
- node->data = e->to;
- avl_insert_before(todo_tree, from, node);
}
- avl_delete_node(todo_tree, from);
+ e->to->status.visited = true;
+ e->to->status.indirect = indirect;
+ 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);
}
- avl_free_tree(todo_tree);
+ list_free(todo_list);
/* Check reachability status. */
n->status.reachable = !n->status.reachable;
if(n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Node %s (%s) became reachable"),
- n->name, n->hostname);
+ 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);
+ 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->status.waitingforkey = false;
+ n->last_req_key = 0;
n->maxmtu = MTU;
n->minmtu = 0;
n->mtuprobes = 0;
- asprintf(&envp[0], "NETNAME=%s", netname ? : "");
- asprintf(&envp[1], "DEVICE=%s", device ? : "");
- asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
- asprintf(&envp[3], "NODE=%s", n->name);
+ 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);
- asprintf(&envp[4], "REMOTEADDRESS=%s", address);
- asprintf(&envp[5], "REMOTEPORT=%s", port);
- envp[6] = NULL;
+ xasprintf(&envp[4], "REMOTEADDRESS=%s", address);
+ xasprintf(&envp[5], "REMOTEPORT=%s", port);
+ xasprintf(&envp[6], "NAME=%s", myself->name);
- asprintf(&name,
- n->status.reachable ? "hosts/%s-up" : "hosts/%s-down",
- n->name);
+ 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 < 7; i++)
+ for(i = 0; i < 7; 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)
-{
- mst_kruskal();
+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;
+ 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(filename);
+ 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
+
+ if(rename(tmpname, filename)) {
+ logger(LOG_ERR, "Could not rename %s to %s: %s\n", tmpname, filename, strerror(errno));
+ }
+
+ free(tmpname);
+ }
+
+ free(filename);
}