src/protocol_edge.c

   1 /*
   2     protocol_edge.c -- handle the meta-protocol, edges
   3     Copyright (C) 1999-2005 Ivo Timmermans,
   4                   2000-2016 Guus Sliepen <guus@tinc-vpn.org>
   5                   2009      Michael Tokarev <mjt@corpit.ru>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License along
  18     with this program; if not, write to the Free Software Foundation, Inc.,
  19     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20 */
  21
  22 #include "system.h"
  23
  24 #include "avl_tree.h"
  25 #include "conf.h"
  26 #include "connection.h"
  27 #include "edge.h"
  28 #include "graph.h"
  29 #include "logger.h"
  30 #include "meta.h"
  31 #include "net.h"
  32 #include "netutl.h"
  33 #include "node.h"
  34 #include "protocol.h"
  35 #include "utils.h"
  36 #include "xalloc.h"
  37
  38 bool send_add_edge(connection_t *c, const edge_t *e) {
  39         bool x;
  40         char *address, *port;
  41
  42         sockaddr2str(&e->address, &address, &port);
  43
  44         x = send_request(c, "%d %x %s %s %s %s %x %d", ADD_EDGE, rand(),
  45                                          e->from->name, e->to->name, address, port,
  46                                          e->options, e->weight);
  47         free(address);
  48         free(port);
  49
  50         return x;
  51 }
  52
  53 bool add_edge_h(connection_t *c) {
  54         edge_t *e;
  55         node_t *from, *to;
  56         char from_name[MAX_STRING_SIZE];
  57         char to_name[MAX_STRING_SIZE];
  58         char to_address[MAX_STRING_SIZE];
  59         char to_port[MAX_STRING_SIZE];
  60         sockaddr_t address;
  61         uint32_t options;
  62         int weight;
  63
  64         if(sscanf(c->buffer, "%*d %*x "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING" %x %d",
  65                           from_name, to_name, to_address, to_port, &options, &weight) != 6) {
  66                 logger(LOG_ERR, "Got bad %s from %s (%s)", "ADD_EDGE", c->name,
  67                            c->hostname);
  68                 return false;
  69         }
  70
  71         /* Check if names are valid */
  72
  73         if(!check_id(from_name) || !check_id(to_name)) {
  74                 logger(LOG_ERR, "Got bad %s from %s (%s): %s", "ADD_EDGE", c->name,
  75                            c->hostname, "invalid name");
  76                 return false;
  77         }
  78
  79         if(seen_request(c->buffer))
  80                 return true;
  81
  82         /* Lookup nodes */
  83
  84         from = lookup_node(from_name);
  85         to = lookup_node(to_name);
  86
  87         if(tunnelserver &&
  88            from != myself && from != c->node &&
  89            to != myself && to != c->node) {
  90                 /* ignore indirect edge registrations for tunnelserver */
  91                 ifdebug(PROTOCOL) logger(LOG_WARNING,
  92                    "Ignoring indirect %s from %s (%s)",
  93                    "ADD_EDGE", c->name, c->hostname);
  94                 return true;
  95         }
  96
  97         if(!from) {
  98                 from = new_node();
  99                 from->name = xstrdup(from_name);
 100                 node_add(from);
 101         }
 102
 103         if(!to) {
 104                 to = new_node();
 105                 to->name = xstrdup(to_name);
 106                 node_add(to);
 107         }
 108
 109
 110         /* Convert addresses */
 111
 112         address = str2sockaddr(to_address, to_port);
 113
 114         /* Check if edge already exists */
 115
 116         e = lookup_edge(from, to);
 117
 118         if(e) {
 119                 if(e->weight != weight || e->options != options || sockaddrcmp(&e->address, &address)) {
 120                         if(from == myself) {
 121                                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 122                                                    "ADD_EDGE", c->name, c->hostname);
 123                                 send_add_edge(c, e);
 124                                 return true;
 125                         } else {
 126                                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) which does not match existing entry",
 127                                                    "ADD_EDGE", c->name, c->hostname);
 128                                 e->options = options;
 129                                 if(sockaddrcmp(&e->address, &address)) {
 130                                         sockaddrfree(&e->address);
 131                                         e->address = address;
 132                                 }
 133                                 if(e->weight != weight) {
 134                                         avl_node_t *node = avl_unlink(edge_weight_tree, e);
 135                                         e->weight = weight;
 136                                         avl_insert_node(edge_weight_tree, node);
 137                                 }
 138
 139                                 goto done;
 140                         }
 141                 } else
 142                         return true;
 143         } else if(from == myself) {
 144                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) for ourself which does not exist",
 145                                    "ADD_EDGE", c->name, c->hostname);
 146                 contradicting_add_edge++;
 147                 e = new_edge();
 148                 e->from = from;
 149                 e->to = to;
 150                 send_del_edge(c, e);
 151                 free_edge(e);
 152                 return true;
 153         }
 154
 155         e = new_edge();
 156         e->from = from;
 157         e->to = to;
 158         e->address = address;
 159         e->options = options;
 160         e->weight = weight;
 161         edge_add(e);
 162
 163 done:
 164         /* Tell the rest about the new edge */
 165
 166         if(!tunnelserver)
 167                 forward_request(c);
 168
 169         /* Run MST before or after we tell the rest? */
 170
 171         graph();
 172
 173         return true;
 174 }
 175
 176 bool send_del_edge(connection_t *c, const edge_t *e) {
 177         return send_request(c, "%d %x %s %s", DEL_EDGE, rand(),
 178                                                 e->from->name, e->to->name);
 179 }
 180
 181 bool del_edge_h(connection_t *c) {
 182         edge_t *e;
 183         char from_name[MAX_STRING_SIZE];
 184         char to_name[MAX_STRING_SIZE];
 185         node_t *from, *to;
 186
 187         if(sscanf(c->buffer, "%*d %*x "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) {
 188                 logger(LOG_ERR, "Got bad %s from %s (%s)", "DEL_EDGE", c->name,
 189                            c->hostname);
 190                 return false;
 191         }
 192
 193         /* Check if names are valid */
 194
 195         if(!check_id(from_name) || !check_id(to_name)) {
 196                 logger(LOG_ERR, "Got bad %s from %s (%s): %s", "DEL_EDGE", c->name,
 197                            c->hostname, "invalid name");
 198                 return false;
 199         }
 200
 201         if(seen_request(c->buffer))
 202                 return true;
 203
 204         /* Lookup nodes */
 205
 206         from = lookup_node(from_name);
 207         to = lookup_node(to_name);
 208
 209         if(tunnelserver &&
 210            from != myself && from != c->node &&
 211            to != myself && to != c->node) {
 212                 /* ignore indirect edge registrations for tunnelserver */
 213                 ifdebug(PROTOCOL) logger(LOG_WARNING,
 214                    "Ignoring indirect %s from %s (%s)",
 215                    "DEL_EDGE", c->name, c->hostname);
 216                 return true;
 217         }
 218
 219         if(!from) {
 220                 ifdebug(PROTOCOL) logger(LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 221                                    "DEL_EDGE", c->name, c->hostname);
 222                 return true;
 223         }
 224
 225         if(!to) {
 226                 ifdebug(PROTOCOL) logger(LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 227                                    "DEL_EDGE", c->name, c->hostname);
 228                 return true;
 229         }
 230
 231         /* Check if edge exists */
 232
 233         e = lookup_edge(from, to);
 234
 235         if(!e) {
 236                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) which does not appear in the edge tree",
 237                                    "DEL_EDGE", c->name, c->hostname);
 238                 return true;
 239         }
 240
 241         if(e->from == myself) {
 242                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) for ourself",
 243                                    "DEL_EDGE", c->name, c->hostname);
 244                 contradicting_del_edge++;
 245                 send_add_edge(c, e);    /* Send back a correction */
 246                 return true;
 247         }
 248
 249         /* Tell the rest about the deleted edge */
 250
 251         if(!tunnelserver)
 252                 forward_request(c);
 253
 254         /* Delete the edge */
 255
 256         edge_del(e);
 257
 258         /* Run MST before or after we tell the rest? */
 259
 260         graph();
 261
 262         /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 263
 264         if(!to->status.reachable) {
 265                 e = lookup_edge(to, myself);
 266                 if(e) {
 267                         if(!tunnelserver)
 268                                 send_del_edge(everyone, e);
 269                         edge_del(e);
 270                 }
 271         }
 272
 273         return true;
 274 }