X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fgraph.c;h=cd7fbf361f80657a607c68e2fcddaf33917a198e;hp=53cf6a99f8b887da5ef4f62ba3fbff866012d165;hb=9d2bf718f233672c11a9740ed2a1539eaab1509b;hpb=87ad5c97a9a73a65050ad7adce34503f856d8665 diff --git a/src/graph.c b/src/graph.c index 53cf6a99..cd7fbf36 100644 --- a/src/graph.c +++ b/src/graph.c @@ -1,7 +1,7 @@ /* graph.c -- graph algorithms - Copyright (C) 2001 Guus Sliepen , - 2001 Ivo Timmermans + Copyright (C) 2001-2003 Guus Sliepen , + 2001-2003 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 @@ -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 1.1.2.4 2001/10/30 12:59:12 guus Exp $ + $Id: graph.c,v 1.1.2.30 2003/10/10 16:23:30 guus Exp $ */ /* We need to generate two trees from the graph: @@ -38,19 +38,23 @@ For the SSSP algorithm Dijkstra's seems to be a nice choice. Currently a simple breadth-first search is presented here. -*/ -#include -#include "config.h" -#include + The SSSP algorithm will also be used to determine whether nodes are directly, + indirectly or not reachable from the source. It will also set the correct + destination address and port of a node if possible. +*/ -#include +#include "system.h" -#include "node.h" -#include "edge.h" +#include "avl_tree.h" #include "connection.h" - -#include "system.h" +#include "device.h" +#include "edge.h" +#include "logger.h" +#include "netutl.h" +#include "node.h" +#include "process.h" +#include "utils.h" /* Implementation of Kruskal's algorithm. Running time: O(EN) @@ -59,58 +63,76 @@ void mst_kruskal(void) { - avl_node_t *node; - edge_t *e; - node_t *n; - connection_t *c; - int nodes = 0; - int safe_edges = 0; - int skipped; - - /* 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; - - /* 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 */ - - while(safe_edges < nodes - 1) - for(skipped = 0, node = edge_weight_tree->head; node; node = node->next) - { - e = (edge_t *)node->data; - - if(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(skipped) - break; - } + 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. @@ -119,62 +141,153 @@ void mst_kruskal(void) void sssp_bfs(void) { - avl_node_t *node, *from, *next, *to; - edge_t *e; - node_t *n, *check; - 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) - { - next = from->next; - n = (node_t *)from->data; - - for(to = n->edge_tree->head; to; to = to->next) - { - e = (edge_t *)to->data; - - if(e->from == n) - check = e->to; - else - check = e->from; - - if(!check->status.visited) - { - check->status.visited = 1; - check->nexthop = (n->nexthop == myself) ? check : n->nexthop; - check->via = check; /* FIXME: only if !(e->options & INDIRECT), otherwise use n->via */ - node = avl_alloc_node(); - node->data = check; - avl_insert_before(todo_tree, from, node); - } - } - - avl_delete_node(todo_tree, from); - } - } - - avl_free_tree(todo_tree); + 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); + } + + 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; + + 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(); }