X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fgraph.c;h=5dfbb72eb9824140f9267e9e3d39abe4d7c28244;hb=8d4ac42ceb67a93fc1e5c0d045819597c5da47d0;hp=29e25db16f16258330b4244ecdb6072046c882ad;hpb=f48f8f4fedba365ceea30e1133bf1c560e9a522a;p=meshlink diff --git a/src/graph.c b/src/graph.c index 29e25db1..9955ea41 100644 --- a/src/graph.c +++ b/src/graph.c @@ -1,7 +1,6 @@ /* graph.c -- graph algorithms - Copyright (C) 2001-2002 Guus Sliepen , - 2001-2002 Ivo Timmermans + Copyright (C) 2014 Guus Sliepen 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 @@ -13,11 +12,9 @@ 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 1.1.2.10 2002/03/19 22:48:25 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: @@ -39,241 +36,161 @@ For the SSSP algorithm Dijkstra's seems to be a nice choice. Currently a simple breadth-first search is presented here. - 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. + The SSSP algorithm will also be used to determine whether nodes are + reachable from the source. It will also set the correct destination address + and port of a node if possible. */ -#include -#include "config.h" -#include -#if defined(HAVE_FREEBSD) || defined(HAVE_OPENBSD) - #include -#endif -#include - -#include -#include +#include "system.h" +#include "connection.h" +#include "edge.h" +#include "graph.h" +#include "list.h" +#include "logger.h" +#include "meshlink_internal.h" #include "netutl.h" #include "node.h" -#include "edge.h" -#include "connection.h" - -#include "system.h" - -/* 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) -{ - 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); -} +#include "protocol.h" +#include "utils.h" +#include "xalloc.h" +#include "graph.h" /* Implementation of a simple breadth-first search algorithm. Running time: O(E) */ -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; - - 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) - { - if(!n->status.reachable) - { - if(debug_lvl >= DEBUG_TRAFFIC) - syslog(LOG_DEBUG, _("Node %s (%s) became reachable"), n->name, n->hostname); - n->status.reachable = 1; +static void sssp_bfs(meshlink_handle_t *mesh) { + list_t *todo_list = list_alloc(NULL); + + /* Clear visited status on nodes */ + + for splay_each(node_t, n, mesh->nodes) { + n->status.visited = false; + n->distance = -1; + } + + /* Begin with mesh->self */ + + mesh->self->status.visited = true; + mesh->self->nexthop = mesh->self; + mesh->self->prevedge = NULL; + mesh->self->distance = 0; + list_insert_head(todo_list, mesh->self); + + /* Loop while todo_list is filled */ + + for list_each(node_t, n, todo_list) { /* "n" is the node from which we start */ + logger(mesh, MESHLINK_DEBUG, " Examining edges from %s", n->name); + + if(n->distance < 0) { + abort(); + } + + for splay_each(edge_t, e, n->edge_tree) { /* "e" is the edge connected to "from" */ + 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 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->to->status.visited + && (e->to->distance != n->distance + 1 || e->weight >= e->to->prevedge->weight)) { + continue; + } + + e->to->status.visited = true; + e->to->nexthop = (n->nexthop == mesh->self) ? e->to : n->nexthop; + e->to->prevedge = e; + e->to->distance = n->distance + 1; + + if(!e->to->status.reachable || (e->to->address.sa.sa_family == AF_UNSPEC && e->address.sa.sa_family != AF_UNKNOWN)) { + update_node_udp(mesh, e->to, &e->address); + } + + list_insert_tail(todo_list, e->to); + } + + next = node->next; /* Because the list_insert_tail() above could have added something extra for us! */ + list_delete_node(todo_list, node); } - } - else - { - if(n->status.reachable) - { - if(debug_lvl >= DEBUG_TRAFFIC) - syslog(LOG_DEBUG, _("Node %s (%s) became unreachable"), n->name, n->hostname); - n->status.reachable = 0; - n->status.validkey = 0; - n->status.waitingforkey = 0; - n->sent_seqno = 0; + + list_free(todo_list); +} + +static void check_reachability(meshlink_handle_t *mesh) { + /* Check reachability status. */ + + for splay_each(node_t, n, mesh->nodes) { + /* Check for nodes that have changed session_id */ + if(n->status.visited && n->prevedge && n->prevedge->reverse->session_id != n->session_id) { + n->session_id = n->prevedge->reverse->session_id; + + if(n->utcp) { + utcp_abort_all_connections(n->utcp); + } + } + + if(n->status.visited != n->status.reachable) { + n->status.reachable = !n->status.reachable; + n->last_state_change = mesh->loop.now.tv_sec; + + if(n->status.reachable) { + logger(mesh, MESHLINK_DEBUG, "Node %s became reachable", n->name); + } else { + logger(mesh, MESHLINK_DEBUG, "Node %s became unreachable", n->name); + } + + /* TODO: only clear status.validkey if node is unreachable? */ + + n->status.validkey = false; + sptps_stop(&n->sptps); + n->status.waitingforkey = false; + n->last_req_key = 0; + + n->status.udp_confirmed = false; + n->maxmtu = MTU; + n->minmtu = 0; + n->mtuprobes = 0; + + timeout_del(&mesh->loop, &n->mtutimeout); + + if(!n->status.blacklisted) { + update_node_status(mesh, n); + } + + if(!n->status.reachable) { + update_node_udp(mesh, n, NULL); + n->status.broadcast = false; + } else if(n->connection) { + if(n->connection->status.initiator) { + send_req_key(mesh, n); + } + } + + if(n->utcp) { + utcp_offline(n->utcp, !n->status.reachable); + } + } } - } - } } -void graph(void) -{ - mst_kruskal(); - sssp_bfs(); +void graph(meshlink_handle_t *mesh) { + sssp_bfs(mesh); + check_reachability(mesh); }