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 "crypto.h"
  26 #include "connection.h"
  27 #include "edge.h"
  28 #include "graph.h"
  29 #include "logger.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
  41         sockaddr2str(&e->address, &address, &port);
  42
  43         if(e->local_address.sa.sa_family) {
  44                 char *local_address, *local_port;
  45                 sockaddr2str(&e->local_address, &local_address, &local_port);
  46
  47                 x = send_request(c, "%d %x %s %s %s %s %x %d %s %s", ADD_EDGE, prng(UINT32_MAX),
  48                                  e->from->name, e->to->name, address, port,
  49                                  e->options, e->weight, local_address, local_port);
  50                 free(local_address);
  51                 free(local_port);
  52         } else {
  53                 x = send_request(c, "%d %x %s %s %s %s %x %d", ADD_EDGE, prng(UINT32_MAX),
  54                                  e->from->name, e->to->name, address, port,
  55                                  e->options, e->weight);
  56         }
  57
  58         free(address);
  59         free(port);
  60
  61         return x;
  62 }
  63
  64 bool add_edge_h(connection_t *c, const char *request) {
  65         edge_t *e;
  66         node_t *from, *to;
  67         char from_name[MAX_STRING_SIZE];
  68         char to_name[MAX_STRING_SIZE];
  69         char to_address[MAX_STRING_SIZE];
  70         char to_port[MAX_STRING_SIZE];
  71         char address_local[MAX_STRING_SIZE];
  72         char port_local[MAX_STRING_SIZE];
  73         sockaddr_t address, local_address = {0};
  74         uint32_t options;
  75         int weight;
  76
  77         int parameter_count = sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING" %x %d "MAX_STRING" "MAX_STRING,
  78                                      from_name, to_name, to_address, to_port, &options, &weight, address_local, port_local);
  79
  80         if(parameter_count != 6 && parameter_count != 8) {
  81                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ADD_EDGE", c->name,
  82                        c->hostname);
  83                 return false;
  84         }
  85
  86         /* Check if names are valid */
  87
  88         if(!check_id(from_name) || !check_id(to_name) || !strcmp(from_name, to_name)) {
  89                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ADD_EDGE", c->name,
  90                        c->hostname, "invalid name");
  91                 return false;
  92         }
  93
  94         if(seen_request(request)) {
  95                 return true;
  96         }
  97
  98         /* Lookup nodes */
  99
 100         from = lookup_node(from_name);
 101         to = lookup_node(to_name);
 102
 103         if(tunnelserver &&
 104                         from != myself && from != c->node &&
 105                         to != myself && to != c->node) {
 106                 /* ignore indirect edge registrations for tunnelserver */
 107                 logger(DEBUG_PROTOCOL, LOG_WARNING,
 108                        "Ignoring indirect %s from %s (%s)",
 109                        "ADD_EDGE", c->name, c->hostname);
 110                 return true;
 111         }
 112
 113         if(!from) {
 114                 from = new_node(from_name);
 115                 node_add(from);
 116         }
 117
 118         if(!to) {
 119                 to = new_node(to_name);
 120                 node_add(to);
 121         }
 122
 123
 124         /* Convert addresses */
 125
 126         address = str2sockaddr(to_address, to_port);
 127
 128         if(parameter_count >= 8) {
 129                 local_address = str2sockaddr(address_local, port_local);
 130         }
 131
 132         /* Check if edge already exists */
 133
 134         e = lookup_edge(from, to);
 135
 136         if(e) {
 137                 bool new_address = sockaddrcmp(&e->address, &address);
 138                 // local_address.sa.sa_family will be 0 if we got it from older tinc versions
 139                 // local_address.sa.sa_family will be 255 (AF_UNKNOWN) if we got it from newer versions
 140                 // but for edge which does not have local_address
 141                 bool new_local_address = local_address.sa.sa_family && local_address.sa.sa_family != AF_UNKNOWN &&
 142                                          sockaddrcmp(&e->local_address, &local_address);
 143
 144                 if(e->weight == weight && e->options == options && !new_address && !new_local_address) {
 145                         sockaddrfree(&address);
 146                         sockaddrfree(&local_address);
 147                         return true;
 148                 }
 149
 150                 if(from == myself) {
 151                         logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 152                                "ADD_EDGE", c->name, c->hostname);
 153                         send_add_edge(c, e);
 154                         sockaddrfree(&address);
 155                         sockaddrfree(&local_address);
 156                         return true;
 157                 }
 158
 159                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not match existing entry",
 160                        "ADD_EDGE", c->name, c->hostname);
 161
 162                 e->options = options;
 163
 164                 if(new_address) {
 165                         sockaddrfree(&e->address);
 166                         e->address = address;
 167                 } else {
 168                         sockaddrfree(&address);
 169                 }
 170
 171                 if(new_local_address) {
 172                         sockaddrfree(&e->local_address);
 173                         e->local_address = local_address;
 174                 } else {
 175                         sockaddrfree(&local_address);
 176                 }
 177
 178                 if(e->weight != weight) {
 179                         splay_node_t *node = splay_unlink(&edge_weight_tree, e);
 180                         e->weight = weight;
 181                         splay_insert_node(&edge_weight_tree, node);
 182                 }
 183         } else if(from == myself) {
 184                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not exist",
 185                        "ADD_EDGE", c->name, c->hostname);
 186                 contradicting_add_edge++;
 187                 e = new_edge();
 188                 e->from = from;
 189                 e->to = to;
 190                 send_del_edge(c, e);
 191                 free_edge(e);
 192                 sockaddrfree(&address);
 193                 sockaddrfree(&local_address);
 194                 return true;
 195         } else {
 196                 e = new_edge();
 197                 e->from = from;
 198                 e->to = to;
 199                 e->address = address;
 200                 e->local_address = local_address;
 201                 e->options = options;
 202                 e->weight = weight;
 203                 edge_add(e);
 204         }
 205
 206         /* Tell the rest about the new edge */
 207
 208         if(!tunnelserver) {
 209                 forward_request(c, request);
 210         }
 211
 212         /* Run MST before or after we tell the rest? */
 213
 214         graph();
 215
 216         return true;
 217 }
 218
 219 bool send_del_edge(connection_t *c, const edge_t *e) {
 220         return send_request(c, "%d %x %s %s", DEL_EDGE, prng(UINT32_MAX),
 221                             e->from->name, e->to->name);
 222 }
 223
 224 bool del_edge_h(connection_t *c, const char *request) {
 225         edge_t *e;
 226         char from_name[MAX_STRING_SIZE];
 227         char to_name[MAX_STRING_SIZE];
 228         node_t *from, *to;
 229
 230         if(sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) {
 231                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "DEL_EDGE", c->name,
 232                        c->hostname);
 233                 return false;
 234         }
 235
 236         /* Check if names are valid */
 237
 238         if(!check_id(from_name) || !check_id(to_name) || !strcmp(from_name, to_name)) {
 239                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "DEL_EDGE", c->name,
 240                        c->hostname, "invalid name");
 241                 return false;
 242         }
 243
 244         if(seen_request(request)) {
 245                 return true;
 246         }
 247
 248         /* Lookup nodes */
 249
 250         from = lookup_node(from_name);
 251         to = lookup_node(to_name);
 252
 253         if(tunnelserver &&
 254                         from != myself && from != c->node &&
 255                         to != myself && to != c->node) {
 256                 /* ignore indirect edge registrations for tunnelserver */
 257                 logger(DEBUG_PROTOCOL, LOG_WARNING,
 258                        "Ignoring indirect %s from %s (%s)",
 259                        "DEL_EDGE", c->name, c->hostname);
 260                 return true;
 261         }
 262
 263         if(!from) {
 264                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 265                        "DEL_EDGE", c->name, c->hostname);
 266                 return true;
 267         }
 268
 269         if(!to) {
 270                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 271                        "DEL_EDGE", c->name, c->hostname);
 272                 return true;
 273         }
 274
 275         /* Check if edge exists */
 276
 277         e = lookup_edge(from, to);
 278
 279         if(!e) {
 280                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not appear in the edge tree",
 281                        "DEL_EDGE", c->name, c->hostname);
 282                 return true;
 283         }
 284
 285         if(e->from == myself) {
 286                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself",
 287                        "DEL_EDGE", c->name, c->hostname);
 288                 contradicting_del_edge++;
 289                 send_add_edge(c, e);    /* Send back a correction */
 290                 return true;
 291         }
 292
 293         /* Tell the rest about the deleted edge */
 294
 295         if(!tunnelserver) {
 296                 forward_request(c, request);
 297         }
 298
 299         /* Delete the edge */
 300
 301         edge_del(e);
 302
 303         /* Run MST before or after we tell the rest? */
 304
 305         graph();
 306
 307         /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 308
 309         if(!to->status.reachable) {
 310                 e = lookup_edge(to, myself);
 311
 312                 if(e) {
 313                         if(!tunnelserver) {
 314                                 send_del_edge(everyone, e);
 315                         }
 316
 317                         edge_del(e);
 318                 }
 319         }
 320
 321         return true;
 322 }