tinc-vpn.org Git - tinc/blob - src/protocol_edge.c

   1 /*
   2     protocol_edge.c -- handle the meta-protocol, edges
   3     Copyright (C) 1999-2005 Ivo Timmermans,
   4                   2000-2012 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 "conf.h"
  25 #include "connection.h"
  26 #include "edge.h"
  27 #include "graph.h"
  28 #include "logger.h"
  29 #include "meta.h"
  30 #include "net.h"
  31 #include "netutl.h"
  32 #include "node.h"
  33 #include "protocol.h"
  34 #include "utils.h"
  35 #include "xalloc.h"
  36
  37 bool send_add_edge(connection_t *c, const edge_t *e) {
  38         bool x;
  39         char *address, *port;
  40         char *local_address, *local_port;
  41
  42         sockaddr2str(&e->address, &address, &port);
  43         sockaddr2str(&e->local_address, &local_address, &local_port);
  44
  45         x = send_request(c, "%d %x %s %s %s %s %x %d %s %s", ADD_EDGE, rand(),
  46                                          e->from->name, e->to->name, address, port,
  47                                          e->options, e->weight, local_address, local_port);
  48
  49         free(address);
  50         free(port);
  51         free(local_address);
  52         free(local_port);
  53
  54         return x;
  55 }
  56
  57 bool add_edge_h(connection_t *c, const char *request) {
  58         edge_t *e;
  59         node_t *from, *to;
  60         char from_name[MAX_STRING_SIZE];
  61         char to_name[MAX_STRING_SIZE];
  62         char to_address[MAX_STRING_SIZE];
  63         char to_port[MAX_STRING_SIZE];
  64         char address_local[MAX_STRING_SIZE];
  65         char port_local[MAX_STRING_SIZE];
  66         sockaddr_t address, local_address = {{0}};
  67         uint32_t options;
  68         int weight;
  69
  70         int parameter_count = sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING" %x %d "MAX_STRING" "MAX_STRING,
  71                                               from_name, to_name, to_address, to_port, &options, &weight, address_local, port_local);
  72         if (parameter_count != 6 && parameter_count != 8) {
  73                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ADD_EDGE", c->name,
  74                            c->hostname);
  75                 return false;
  76         }
  77
  78         /* Check if names are valid */
  79
  80         if(!check_id(from_name) || !check_id(to_name)) {
  81                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ADD_EDGE", c->name,
  82                            c->hostname, "invalid name");
  83                 return false;
  84         }
  85
  86         if(seen_request(request))
  87                 return true;
  88
  89         /* Lookup nodes */
  90
  91         from = lookup_node(from_name);
  92         to = lookup_node(to_name);
  93
  94         if(tunnelserver &&
  95            from != myself && from != c->node &&
  96            to != myself && to != c->node) {
  97                 /* ignore indirect edge registrations for tunnelserver */
  98                 logger(DEBUG_PROTOCOL, LOG_WARNING,
  99                    "Ignoring indirect %s from %s (%s)",
 100                    "ADD_EDGE", c->name, c->hostname);
 101                 return true;
 102         }
 103
 104         if(!from) {
 105                 from = new_node();
 106                 from->name = xstrdup(from_name);
 107                 node_add(from);
 108         }
 109
 110         if(!to) {
 111                 to = new_node();
 112                 to->name = xstrdup(to_name);
 113                 node_add(to);
 114         }
 115
 116
 117         /* Convert addresses */
 118
 119         address = str2sockaddr(to_address, to_port);
 120         if(parameter_count >= 8)
 121                 local_address = str2sockaddr(address_local, port_local);
 122
 123         /* Check if edge already exists */
 124
 125         e = lookup_edge(from, to);
 126
 127         if(e) {
 128                 if(e->weight != weight || e->options != options || sockaddrcmp(&e->address, &address)) {
 129                         if(from == myself) {
 130                                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 131                                                    "ADD_EDGE", c->name, c->hostname);
 132                                 send_add_edge(c, e);
 133                                 return true;
 134                         } else {
 135                                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not match existing entry",
 136                                                    "ADD_EDGE", c->name, c->hostname);
 137                                 edge_del(e);
 138                                 graph();
 139                         }
 140                 } else if(sockaddrcmp(&e->local_address, &local_address)) {
 141                         if(from == myself) {
 142                                 if(e->local_address.sa.sa_family && local_address.sa.sa_family) {
 143                                         // Someone has the wrong local address for ourself. Correct then.
 144                                         logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 145                                                            "ADD_EDGE", c->name, c->hostname);
 146                                         send_add_edge(c, e);
 147                                         return true;
 148                                 }
 149                                 // Otherwise, just ignore it.
 150                                 return true;
 151                         } else if(local_address.sa.sa_family) {
 152                                 // We learned a new local address for this edge.
 153                                 sockaddrfree(&e->local_address);
 154                                 e->local_address = local_address;
 155
 156                                 // Tell others about it.
 157                                 if(!tunnelserver)
 158                                         forward_request(c, request);
 159
 160                                 return true;
 161                         }
 162                 } else
 163                         return true;
 164         } else if(from == myself) {
 165                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not exist",
 166                                    "ADD_EDGE", c->name, c->hostname);
 167                 contradicting_add_edge++;
 168                 e = new_edge();
 169                 e->from = from;
 170                 e->to = to;
 171                 send_del_edge(c, e);
 172                 free_edge(e);
 173                 return true;
 174         }
 175
 176         e = new_edge();
 177         e->from = from;
 178         e->to = to;
 179         e->address = address;
 180         e->local_address = local_address;
 181         e->options = options;
 182         e->weight = weight;
 183         edge_add(e);
 184
 185         /* Tell the rest about the new edge */
 186
 187         if(!tunnelserver)
 188                 forward_request(c, request);
 189
 190         /* Run MST before or after we tell the rest? */
 191
 192         graph();
 193
 194         return true;
 195 }
 196
 197 bool send_del_edge(connection_t *c, const edge_t *e) {
 198         return send_request(c, "%d %x %s %s", DEL_EDGE, rand(),
 199                                                 e->from->name, e->to->name);
 200 }
 201
 202 bool del_edge_h(connection_t *c, const char *request) {
 203         edge_t *e;
 204         char from_name[MAX_STRING_SIZE];
 205         char to_name[MAX_STRING_SIZE];
 206         node_t *from, *to;
 207
 208         if(sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) {
 209                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "DEL_EDGE", c->name,
 210                            c->hostname);
 211                 return false;
 212         }
 213
 214         /* Check if names are valid */
 215
 216         if(!check_id(from_name) || !check_id(to_name)) {
 217                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "DEL_EDGE", c->name,
 218                            c->hostname, "invalid name");
 219                 return false;
 220         }
 221
 222         if(seen_request(request))
 223                 return true;
 224
 225         /* Lookup nodes */
 226
 227         from = lookup_node(from_name);
 228         to = lookup_node(to_name);
 229
 230         if(tunnelserver &&
 231            from != myself && from != c->node &&
 232            to != myself && to != c->node) {
 233                 /* ignore indirect edge registrations for tunnelserver */
 234                 logger(DEBUG_PROTOCOL, LOG_WARNING,
 235                    "Ignoring indirect %s from %s (%s)",
 236                    "DEL_EDGE", c->name, c->hostname);
 237                 return true;
 238         }
 239
 240         if(!from) {
 241                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 242                                    "DEL_EDGE", c->name, c->hostname);
 243                 return true;
 244         }
 245
 246         if(!to) {
 247                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 248                                    "DEL_EDGE", c->name, c->hostname);
 249                 return true;
 250         }
 251
 252         /* Check if edge exists */
 253
 254         e = lookup_edge(from, to);
 255
 256         if(!e) {
 257                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not appear in the edge tree",
 258                                    "DEL_EDGE", c->name, c->hostname);
 259                 return true;
 260         }
 261
 262         if(e->from == myself) {
 263                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself",
 264                                    "DEL_EDGE", c->name, c->hostname);
 265                 contradicting_del_edge++;
 266                 send_add_edge(c, e);    /* Send back a correction */
 267                 return true;
 268         }
 269
 270         /* Tell the rest about the deleted edge */
 271
 272         if(!tunnelserver)
 273                 forward_request(c, request);
 274
 275         /* Delete the edge */
 276
 277         edge_del(e);
 278
 279         /* Run MST before or after we tell the rest? */
 280
 281         graph();
 282
 283         /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 284
 285         if(!to->status.reachable) {
 286                 e = lookup_edge(to, myself);
 287                 if(e) {
 288                         if(!tunnelserver)
 289                                 send_del_edge(everyone, e);
 290                         edge_del(e);
 291                 }
 292         }
 293
 294         return true;
 295 }