Improvements for PMTU discovery and IPv4 packet fragmentation.
[tinc] / src / graph.c
index 6841ff2..3ed1d72 100644 (file)
@@ -1,7 +1,7 @@
 /*
     graph.c -- graph algorithms
-    Copyright (C) 2001-2002 Guus Sliepen <guus@sliepen.eu.org>,
-                  2001-2002 Ivo Timmermans <ivo@o2w.nl>
+    Copyright (C) 2001-2003 Guus Sliepen <guus@sliepen.eu.org>,
+                  2001-2003 Ivo Timmermans <ivo@o2w.nl>
 
     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
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: graph.c,v 1.1.2.16 2002/09/06 09:48:39 guus Exp $
+    $Id: graph.c,v 1.1.2.34 2003/12/22 11:04:16 guus Exp $
 */
 
 /* We need to generate two trees from the graph:
    destination address and port of a node if possible.
 */
 
-#include "config.h"
-
-#include <stdio.h>
-#include <syslog.h>
-#include "config.h"
-#include <string.h>
-#ifdef HAVE_SYS_PARAM_H
- #include <sys/param.h>
-#endif
-#include <netinet/in.h>
-
-#include <avl_tree.h>
-#include <utils.h>
+#include "system.h"
 
+#include "avl_tree.h"
+#include "connection.h"
+#include "device.h"
+#include "edge.h"
+#include "logger.h"
 #include "netutl.h"
 #include "node.h"
-#include "edge.h"
-#include "connection.h"
 #include "process.h"
-#include "device.h"
-
-#include "system.h"
+#include "utils.h"
 
 /* Implementation of Kruskal's algorithm.
    Running time: O(EN)
 
 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->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;
-
-      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);
+       avl_node_t *node, *next;
+       edge_t *e;
+       node_t *n;
+       connection_t *c;
+       int nodes = 0;
+       int safe_edges = 0;
+       bool skipped;
+
+       cp();
+       
+       /* 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 */
+
+       ((edge_t *) edge_weight_tree->head->data)->from->status.visited = true;
+
+       /* 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.
@@ -152,144 +141,165 @@ void mst_kruskal(void)
 
 void sssp_bfs(void)
 {
-  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;
-
-  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?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;
+       bool 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->data;
+               n->status.visited = false;
+               n->status.indirect = true;
+       }
+
+       /* Begin with myself */
+
+       myself->status.visited = true;
+       myself->status.indirect = false;
+       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 = 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 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 = true;
+                               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);
+                                       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);
+               }
+       }
+
+       avl_free_tree(todo_tree);
+
+       /* 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);
+                       }
+
+                       n->status.validkey = false;
+                       n->status.waitingforkey = false;
+
+                       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);
+                       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();
 }