along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: graph.c,v 1.1.2.14 2002/07/10 11:27:06 guus Exp $
+ $Id: graph.c,v 1.1.2.21 2002/09/10 22:12:33 guus Exp $
*/
/* We need to generate two trees from the graph:
#include <stdio.h>
#include <syslog.h>
-#include "config.h"
#include <string.h>
#ifdef HAVE_SYS_PARAM_H
- #include <sys/param.h>
+#include <sys/param.h>
#endif
#include <netinet/in.h>
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;
-
- /* Clear MST status on connections */
-
- for(node = connection_tree->head; node; node = node->next)
- {
- c = (connection_t *)node->data;
- c->status.mst = 0;
- }
-
- /* Do we have something to do at all? */
-
- if(!edge_weight_tree->head)
- return;
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- syslog(LOG_DEBUG, "Running Kruskal's algorithm:");
-
- /* 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;
-
- /* 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(debug_lvl >= DEBUG_SCARY_THINGS)
- syslog(LOG_DEBUG, " Adding edge %s - %s weight %d", e->from.node->name, e->to.node->name, e->weight);
-
- if(skipped)
- {
- next = edge_weight_tree->head;
- continue;
- }
- }
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- syslog(LOG_DEBUG, "Done, counted %d nodes and %d safe edges.", nodes, safe_edges);
+ avl_node_t *node, *next;
+ edge_t *e;
+ node_t *n;
+ connection_t *c;
+ int nodes = 0;
+ int safe_edges = 0;
+ int skipped;
+
+ cp();
+
+ /* Clear MST status on connections */
+
+ for(node = connection_tree->head; node; node = node->next) {
+ c = (connection_t *) node->data;
+ c->status.mst = 0;
+ }
+
+ /* Do we have something to do at all? */
+
+ if(!edge_weight_tree->head)
+ return;
+
+ if(debug_lvl >= DEBUG_SCARY_THINGS)
+ syslog(LOG_DEBUG, "Running Kruskal's algorithm:");
+
+ /* 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->status.visited = 1;
+
+ /* Add safe edges */
+
+ for(skipped = 0, node = edge_weight_tree->head; node; node = next) {
+ next = node->next;
+ e = (edge_t *) node->data;
+
+ if(!e->reverse || e->from->status.visited == e->to->status.visited) {
+ skipped = 1;
+ continue;
+ }
+
+ e->from->status.visited = 1;
+ e->to->status.visited = 1;
+
+ if(e->connection)
+ e->connection->status.mst = 1;
+
+ if(e->reverse->connection)
+ e->reverse->connection->status.mst = 1;
+
+ safe_edges++;
+
+ if(debug_lvl >= DEBUG_SCARY_THINGS)
+ syslog(LOG_DEBUG, " Adding edge %s - %s weight %d", e->from->name,
+ e->to->name, e->weight);
+
+ if(skipped) {
+ skipped = 0;
+ next = edge_weight_tree->head;
+ continue;
+ }
+ }
+
+ if(debug_lvl >= DEBUG_SCARY_THINGS)
+ syslog(LOG_DEBUG, "Done, counted %d nodes and %d safe edges.", nodes,
+ safe_edges);
}
/* Implementation of a simple breadth-first search algorithm.
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;
- int indirect;
- char *name;
- char *address, *port;
- char *envp[7];
- int i;
-
- 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;
- n->status.indirect = 1;
- }
-
- /* Begin with myself */
-
- myself->status.visited = 1;
- myself->status.indirect = 0;
- 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;
-
- /* Situation:
-
- /
- /
- ------(n)from_hc-----to_hc
- \
- \
-
- n->address is set to the to_hc.udpaddress of the edge left of n.
- We are currently examining the edge right of n:
-
- - If from_hc.udpaddress != n->address, then to_hc.node 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 to_hc.node, update
- to_hc.node 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 || ((n != myself) && sockaddrcmp(&n->address, &from_hc.udpaddress));
-
- if(to_hc.node->status.visited && (!to_hc.node->status.indirect || indirect))
- continue;
-
- to_hc.node->status.visited = 1;
- to_hc.node->status.indirect = indirect;
- to_hc.node->nexthop = (n->nexthop == myself) ? to_hc.node : n->nexthop;
- to_hc.node->via = indirect ? n->via : to_hc.node;
- to_hc.node->options = e->options;
- if(sockaddrcmp(&to_hc.node->address, &to_hc.udpaddress))
- {
- node = avl_unlink(node_udp_tree, to_hc.node);
- to_hc.node->address = to_hc.udpaddress;
- if(to_hc.node->hostname)
- free(to_hc.node->hostname);
- to_hc.node->hostname = sockaddr2hostname(&to_hc.udpaddress);
- avl_insert_node(node_udp_tree, node);
- }
- 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 ^ n->status.reachable)
- {
- n->status.reachable = !n->status.reachable;
- if(debug_lvl >= DEBUG_TRAFFIC)
- if(n->status.reachable)
- syslog(LOG_DEBUG, _("Node %s (%s) became reachable"), n->name, n->hostname);
- else
- syslog(LOG_DEBUG, _("Node %s (%s) became unreachable"), n->name, n->hostname);
-
- if(!n->status.reachable)
- {
- n->status.reachable = 0;
- n->status.validkey = 0;
- n->status.waitingforkey = 0;
- n->sent_seqno = 0;
- }
-
- asprintf(&envp[0], "NETNAME=%s", netname?netname:"");
- asprintf(&envp[1], "DEVICE=%s", device?device:"");
- asprintf(&envp[2], "INTERFACE=%s", interface?interface:"");
- asprintf(&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;
-
- asprintf(&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++)
- free(envp[i]);
- }
- }
+ avl_node_t *node, *from, *next, *to;
+ edge_t *e;
+ node_t *n;
+ avl_tree_t *todo_tree;
+ int indirect;
+ char *name;
+ char *address, *port;
+ char *envp[7];
+ int i;
+
+ cp();
+
+ 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;
+ n->status.indirect = 1;
+ }
+
+ /* Begin with myself */
+
+ myself->status.visited = 1;
+ myself->status.indirect = 0;
+ 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->reverse)
+ continue;
+
+ /* Situation:
+
+ /
+ /
+ ------(n)-----(e->to)
+ \
+ \
+
+ 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_tree 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));
+
+ if(e->to->status.visited
+ && (!e->to->status.indirect || indirect))
+ continue;
+
+ e->to->status.visited = 1;
+ 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 = avl_unlink(node_udp_tree, e->to);
+ 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);
+ }
+
+ node = avl_alloc_node();
+ node->data = e->to;
+ 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 != n->status.reachable) {
+ n->status.reachable = !n->status.reachable;
+
+ if(debug_lvl >= DEBUG_TRAFFIC) {
+ if(n->status.reachable)
+ syslog(LOG_DEBUG, _("Node %s (%s) became reachable"),
+ n->name, n->hostname);
+ else
+ syslog(LOG_DEBUG, _("Node %s (%s) became unreachable"),
+ n->name, n->hostname);
+ }
+
+ n->status.validkey = 0;
+ n->status.waitingforkey = 0;
+
+ asprintf(&envp[0], "NETNAME=%s", netname ? : "");
+ asprintf(&envp[1], "DEVICE=%s", device ? : "");
+ asprintf(&envp[2], "INTERFACE=%s", interface ? : "");
+ asprintf(&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;
+
+ asprintf(&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++)
+ free(envp[i]);
+ }
+ }
}
void graph(void)
{
- mst_kruskal();
- sssp_bfs();
+ mst_kruskal();
+ sssp_bfs();
}
projects / tinc / blobdiff