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 "net.h"
  30 #include "netutl.h"
  31 #include "node.h"
  32 #include "protocol.h"
  33 #include "utils.h"
  34 #include "xalloc.h"
  35
  36 bool send_add_edge(connection_t *c, const edge_t *e) {
  37         bool x;
  38         char *address, *port;
  39
  40         sockaddr2str(&e->address, &address, &port);
  41
  42         if(e->local_address.sa.sa_family) {
  43                 char *local_address, *local_port;
  44                 sockaddr2str(&e->local_address, &local_address, &local_port);
  45
  46                 x = send_request(c, "%d %x %s %s %s %s %x %d %s %s", ADD_EDGE, rand(),
  47                                  e->from->name, e->to->name, address, port,
  48                                  e->options, e->weight, local_address, local_port);
  49                 free(local_address);
  50                 free(local_port);
  51         } else {
  52                 x = send_request(c, "%d %x %s %s %s %s %x %d", ADD_EDGE, rand(),
  53                                  e->from->name, e->to->name, address, port,
  54                                  e->options, e->weight);
  55         }
  56
  57         free(address);
  58         free(port);
  59
  60         return x;
  61 }
  62
  63 bool add_edge_h(connection_t *c, const char *request) {
  64         edge_t *e;
  65         node_t *from, *to;
  66         char from_name[MAX_STRING_SIZE];
  67         char to_name[MAX_STRING_SIZE];
  68         char to_address[MAX_STRING_SIZE];
  69         char to_port[MAX_STRING_SIZE];
  70         char address_local[MAX_STRING_SIZE];
  71         char port_local[MAX_STRING_SIZE];
  72         sockaddr_t address, local_address = {0};
  73         uint32_t options;
  74         int weight;
  75
  76         int parameter_count = sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING" %x %d "MAX_STRING" "MAX_STRING,
  77                                      from_name, to_name, to_address, to_port, &options, &weight, address_local, port_local);
  78
  79         if(parameter_count != 6 && parameter_count != 8) {
  80                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ADD_EDGE", c->name,
  81                        c->hostname);
  82                 return false;
  83         }
  84
  85         /* Check if names are valid */
  86
  87         if(!check_id(from_name) || !check_id(to_name) || !strcmp(from_name, to_name)) {
  88                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ADD_EDGE", c->name,
  89                        c->hostname, "invalid name");
  90                 return false;
  91         }
  92
  93         if(seen_request(request)) {
  94                 return true;
  95         }
  96
  97         /* Lookup nodes */
  98
  99         from = lookup_node(from_name);
 100         to = lookup_node(to_name);
 101
 102         if(tunnelserver &&
 103                         from != myself && from != c->node &&
 104                         to != myself && to != c->node) {
 105                 /* ignore indirect edge registrations for tunnelserver */
 106                 logger(DEBUG_PROTOCOL, LOG_WARNING,
 107                        "Ignoring indirect %s from %s (%s)",
 108                        "ADD_EDGE", c->name, c->hostname);
 109                 return true;
 110         }
 111
 112         if(!from) {
 113                 from = new_node();
 114                 from->name = xstrdup(from_name);
 115                 node_add(from);
 116         }
 117
 118         if(!to) {
 119                 to = new_node();
 120                 to->name = xstrdup(to_name);
 121                 node_add(to);
 122         }
 123
 124
 125         /* Convert addresses */
 126
 127         address = str2sockaddr(to_address, to_port);
 128
 129         if(parameter_count >= 8) {
 130                 local_address = str2sockaddr(address_local, port_local);
 131         }
 132
 133         /* Check if edge already exists */
 134
 135         e = lookup_edge(from, to);
 136
 137         if(e) {
 138                 bool new_address = sockaddrcmp(&e->address, &address);
 139                 // local_address.sa.sa_family will be 0 if we got it from older tinc versions
 140                 // local_address.sa.sa_family will be 255 (AF_UNKNOWN) if we got it from newer versions
 141                 // but for edge which does not have local_address
 142                 bool new_local_address = local_address.sa.sa_family && local_address.sa.sa_family != AF_UNKNOWN &&
 143                                          sockaddrcmp(&e->local_address, &local_address);
 144
 145                 if(e->weight == weight && e->options == options && !new_address && !new_local_address) {
 146                         sockaddrfree(&address);
 147                         sockaddrfree(&local_address);
 148                         return true;
 149                 }
 150
 151                 if(from == myself) {
 152                         logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 153                                "ADD_EDGE", c->name, c->hostname);
 154                         send_add_edge(c, e);
 155                         sockaddrfree(&address);
 156                         sockaddrfree(&local_address);
 157                         return true;
 158                 }
 159
 160                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not match existing entry",
 161                        "ADD_EDGE", c->name, c->hostname);
 162
 163                 e->options = options;
 164
 165                 if(new_address) {
 166                         sockaddrfree(&e->address);
 167                         e->address = address;
 168                 } else {
 169                         sockaddrfree(&address);
 170                 }
 171
 172                 if(new_local_address) {
 173                         sockaddrfree(&e->local_address);
 174                         e->local_address = local_address;
 175                 } else {
 176                         sockaddrfree(&local_address);
 177                 }
 178
 179                 if(e->weight != weight) {
 180                         splay_node_t *node = splay_unlink(edge_weight_tree, e);
 181                         e->weight = weight;
 182                         splay_insert_node(edge_weight_tree, node);
 183                 }
 184         } else if(from == myself) {
 185                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not exist",
 186                        "ADD_EDGE", c->name, c->hostname);
 187                 contradicting_add_edge++;
 188                 e = new_edge();
 189                 e->from = from;
 190                 e->to = to;
 191                 send_del_edge(c, e);
 192                 free_edge(e);
 193                 sockaddrfree(&address);
 194                 sockaddrfree(&local_address);
 195                 return true;
 196         } else {
 197                 e = new_edge();
 198                 e->from = from;
 199                 e->to = to;
 200                 e->address = address;
 201                 e->local_address = local_address;
 202                 e->options = options;
 203                 e->weight = weight;
 204                 edge_add(e);
 205         }
 206
 207         /* Tell the rest about the new edge */
 208
 209         if(!tunnelserver) {
 210                 forward_request(c, request);
 211         }
 212
 213         /* Run MST before or after we tell the rest? */
 214
 215         graph();
 216
 217         return true;
 218 }
 219
 220 bool send_del_edge(connection_t *c, const edge_t *e) {
 221         return send_request(c, "%d %x %s %s", DEL_EDGE, rand(),
 222                             e->from->name, e->to->name);
 223 }
 224
 225 bool del_edge_h(connection_t *c, const char *request) {
 226         edge_t *e;
 227         char from_name[MAX_STRING_SIZE];
 228         char to_name[MAX_STRING_SIZE];
 229         node_t *from, *to;
 230
 231         if(sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) {
 232                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "DEL_EDGE", c->name,
 233                        c->hostname);
 234                 return false;
 235         }
 236
 237         /* Check if names are valid */
 238
 239         if(!check_id(from_name) || !check_id(to_name) || !strcmp(from_name, to_name)) {
 240                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "DEL_EDGE", c->name,
 241                        c->hostname, "invalid name");
 242                 return false;
 243         }
 244
 245         if(seen_request(request)) {
 246                 return true;
 247         }
 248
 249         /* Lookup nodes */
 250
 251         from = lookup_node(from_name);
 252         to = lookup_node(to_name);
 253
 254         if(tunnelserver &&
 255                         from != myself && from != c->node &&
 256                         to != myself && to != c->node) {
 257                 /* ignore indirect edge registrations for tunnelserver */
 258                 logger(DEBUG_PROTOCOL, LOG_WARNING,
 259                        "Ignoring indirect %s from %s (%s)",
 260                        "DEL_EDGE", c->name, c->hostname);
 261                 return true;
 262         }
 263
 264         if(!from) {
 265                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 266                        "DEL_EDGE", c->name, c->hostname);
 267                 return true;
 268         }
 269
 270         if(!to) {
 271                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 272                        "DEL_EDGE", c->name, c->hostname);
 273                 return true;
 274         }
 275
 276         /* Check if edge exists */
 277
 278         e = lookup_edge(from, to);
 279
 280         if(!e) {
 281                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not appear in the edge tree",
 282                        "DEL_EDGE", c->name, c->hostname);
 283                 return true;
 284         }
 285
 286         if(e->from == myself) {
 287                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself",
 288                        "DEL_EDGE", c->name, c->hostname);
 289                 contradicting_del_edge++;
 290                 send_add_edge(c, e);    /* Send back a correction */
 291                 return true;
 292         }
 293
 294         /* Tell the rest about the deleted edge */
 295
 296         if(!tunnelserver) {
 297                 forward_request(c, request);
 298         }
 299
 300         /* Delete the edge */
 301
 302         edge_del(e);
 303
 304         /* Run MST before or after we tell the rest? */
 305
 306         graph();
 307
 308         /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 309
 310         if(!to->status.reachable) {
 311                 e = lookup_edge(to, myself);
 312
 313                 if(e) {
 314                         if(!tunnelserver) {
 315                                 send_del_edge(everyone, e);
 316                         }
 317
 318                         edge_del(e);
 319                 }
 320         }
 321
 322         return true;
 323 }