Nexthop calculation should always use the shortest path.
[tinc] / src / graph.c
index 5dfbb72..9592f98 100644 (file)
@@ -1,6 +1,6 @@
 /*
     graph.c -- graph algorithms
-    Copyright (C) 2001-2007 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
     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.
-
-    $Id$
+    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 "config.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;
 
@@ -65,8 +66,7 @@ static bool graph_changed = true;
    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;
@@ -75,8 +75,6 @@ void mst_kruskal(void)
        int safe_edges = 0;
        bool skipped;
 
-       cp();
-       
        /* Clear MST status on connections */
 
        for(node = connection_tree->head; node; node = node->next) {
@@ -149,8 +147,7 @@ void mst_kruskal(void)
    Running time: O(E)
 */
 
-void sssp_bfs(void)
-{
+static void sssp_bfs(void) {
        avl_node_t *node, *next, *to;
        edge_t *e;
        node_t *n;
@@ -159,11 +156,9 @@ void sssp_bfs(void)
        bool indirect;
        char *name;
        char *address, *port;
-       char *envp[7];
+       char *envp[8] = {NULL};
        int i;
 
-       cp();
-
        todo_list = list_alloc(NULL);
 
        /* Clear visited status on nodes */
@@ -179,6 +174,7 @@ void sssp_bfs(void)
        myself->status.visited = true;
        myself->status.indirect = false;
        myself->nexthop = myself;
+       myself->prevedge = NULL;
        myself->via = myself;
        list_insert_head(todo_list, myself);
 
@@ -205,48 +201,30 @@ void sssp_bfs(void)
                           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));
+                       indirect = n->status.indirect || e->options & OPTION_INDIRECT;
 
                        if(e->to->status.visited
                           && (!e->to->status.indirect || indirect))
                                continue;
 
+                       // Only update nexthop the first time we visit this node.
+
+                       if(!e->to->status.visited)
+                               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;
 
-                       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);
-
-                               if(node)
-                                       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);
-                               }
-                       }
+                       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);
                }
@@ -267,34 +245,39 @@ void sssp_bfs(void)
                        n->status.reachable = !n->status.reachable;
 
                        if(n->status.reachable) {
-                               ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Node %s (%s) became reachable"),
+                               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became reachable",
                                           n->name, n->hostname);
-                               avl_insert(node_udp_tree, n);
                        } else {
-                               ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Node %s (%s) became unreachable"),
+                               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Node %s (%s) became unreachable",
                                           n->name, n->hostname);
-                               avl_delete(node_udp_tree, n);
                        }
 
+                       /* 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);
 
                        execute_script(n->status.reachable ? "host-up" : "host-down", envp);
 
-                       asprintf(&name,
+                       xasprintf(&name,
                                         n->status.reachable ? "hosts/%s-up" : "hosts/%s-down",
                                         n->name);
                        execute_script(name, envp);
@@ -303,16 +286,24 @@ void sssp_bfs(void)
                        free(address);
                        free(port);
 
-                       for(i = 0; i < 6; 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)
-{
+void graph(void) {
+       subnet_cache_flush();
        sssp_bfs();
        mst_kruskal();
        graph_changed = true;
@@ -326,13 +317,12 @@ void graph(void)
    dot -Tpng graph_filename -o image_filename.png -Gconcentrate=true
 */
 
-void dump_graph(void)
-{
+void dump_graph(void) {
        avl_node_t *node;
        node_t *n;
        edge_t *e;
        char *filename = NULL, *tmpname = NULL;
-       FILE *file;
+       FILE *file, *pipe = NULL;
        
        if(!graph_changed || !get_config_string(lookup_config(config_tree, "GraphDumpFile"), &filename))
                return;
@@ -342,9 +332,9 @@ void dump_graph(void)
        ifdebug(PROTOCOL) logger(LOG_NOTICE, "Dumping graph");
        
        if(filename[0] == '|') {
-               file = popen(filename + 1, "w");
+               file = pipe = popen(filename + 1, "w");
        } else {
-               asprintf(&tmpname, "%s.new", filename);
+               xasprintf(&tmpname, "%s.new", filename);
                file = fopen(tmpname, "w");
        }
 
@@ -370,8 +360,8 @@ void dump_graph(void)
 
        fprintf(file, "}\n");   
        
-       if(filename[0] == '|') {
-               pclose(file);
+       if(pipe) {
+               pclose(pipe);
        } else {
                fclose(file);
 #ifdef HAVE_MINGW