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
  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, rand(),
  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, rand(),
  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         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)) {
  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         /* Lookup nodes */
  97
  98         from = lookup_node(from_name);
  99         to = lookup_node(to_name);
 100
 101         if(tunnelserver &&
 102            from != myself && from != c->node &&
 103            to != myself && to != c->node) {
 104                 /* ignore indirect edge registrations for tunnelserver */
 105                 logger(DEBUG_PROTOCOL, LOG_WARNING,
 106                    "Ignoring indirect %s from %s (%s)",
 107                    "ADD_EDGE", c->name, c->hostname);
 108                 return true;
 109         }
 110
 111         if(!from) {
 112                 from = new_node();
 113                 from->name = xstrdup(from_name);
 114                 node_add(from);
 115         }
 116
 117         if(!to) {
 118                 to = new_node();
 119                 to->name = xstrdup(to_name);
 120                 node_add(to);
 121         }
 122
 123
 124         /* Convert addresses */
 125
 126         address = str2sockaddr(to_address, to_port);
 127         if(parameter_count >= 8)
 128                 local_address = str2sockaddr(address_local, port_local);
 129
 130         /* Check if edge already exists */
 131
 132         e = lookup_edge(from, to);
 133
 134         if(e) {
 135                 if(e->weight != weight || e->options != options || sockaddrcmp(&e->address, &address)) {
 136                         if(from == myself) {
 137                                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 138                                                    "ADD_EDGE", c->name, c->hostname);
 139                                 send_add_edge(c, e);
 140                                 sockaddrfree(&local_address);
 141                                 return true;
 142                         } else {
 143                                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not match existing entry",
 144                                                    "ADD_EDGE", c->name, c->hostname);
 145                                 edge_del(e);
 146                                 graph();
 147                         }
 148                 } else if(sockaddrcmp(&e->local_address, &local_address)) {
 149                         if(from == myself) {
 150                                 if(e->local_address.sa.sa_family && local_address.sa.sa_family) {
 151                                         // Someone has the wrong local address for ourself. Correct then.
 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(&local_address);
 156                                         return true;
 157                                 }
 158                                 // Otherwise, just ignore it.
 159                                 sockaddrfree(&local_address);
 160                                 return true;
 161                         } else if(local_address.sa.sa_family) {
 162                                 // We learned a new local address for this edge.
 163                                 sockaddrfree(&e->local_address);
 164                                 e->local_address = local_address;
 165
 166                                 // Tell others about it.
 167                                 if(!tunnelserver)
 168                                         forward_request(c, request);
 169
 170                                 return true;
 171                         } else {
 172                                 return true;
 173                         }
 174                 } else {
 175                         sockaddrfree(&local_address);
 176                         return true;
 177                 }
 178         } else if(from == myself) {
 179                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not exist",
 180                                    "ADD_EDGE", c->name, c->hostname);
 181                 contradicting_add_edge++;
 182                 e = new_edge();
 183                 e->from = from;
 184                 e->to = to;
 185                 send_del_edge(c, e);
 186                 free_edge(e);
 187                 sockaddrfree(&local_address);
 188                 return true;
 189         }
 190
 191         e = new_edge();
 192         e->from = from;
 193         e->to = to;
 194         e->address = address;
 195         e->local_address = local_address;
 196         e->options = options;
 197         e->weight = weight;
 198         edge_add(e);
 199
 200         /* Tell the rest about the new edge */
 201
 202         if(!tunnelserver)
 203                 forward_request(c, request);
 204
 205         /* Run MST before or after we tell the rest? */
 206
 207         graph();
 208
 209         return true;
 210 }
 211
 212 bool send_del_edge(connection_t *c, const edge_t *e) {
 213         return send_request(c, "%d %x %s %s", DEL_EDGE, rand(),
 214                                                 e->from->name, e->to->name);
 215 }
 216
 217 bool del_edge_h(connection_t *c, const char *request) {
 218         edge_t *e;
 219         char from_name[MAX_STRING_SIZE];
 220         char to_name[MAX_STRING_SIZE];
 221         node_t *from, *to;
 222
 223         if(sscanf(request, "%*d %*x "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) {
 224                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "DEL_EDGE", c->name,
 225                            c->hostname);
 226                 return false;
 227         }
 228
 229         /* Check if names are valid */
 230
 231         if(!check_id(from_name) || !check_id(to_name)) {
 232                 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "DEL_EDGE", c->name,
 233                            c->hostname, "invalid name");
 234                 return false;
 235         }
 236
 237         if(seen_request(request))
 238                 return true;
 239
 240         /* Lookup nodes */
 241
 242         from = lookup_node(from_name);
 243         to = lookup_node(to_name);
 244
 245         if(tunnelserver &&
 246            from != myself && from != c->node &&
 247            to != myself && to != c->node) {
 248                 /* ignore indirect edge registrations for tunnelserver */
 249                 logger(DEBUG_PROTOCOL, LOG_WARNING,
 250                    "Ignoring indirect %s from %s (%s)",
 251                    "DEL_EDGE", c->name, c->hostname);
 252                 return true;
 253         }
 254
 255         if(!from) {
 256                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 257                                    "DEL_EDGE", c->name, c->hostname);
 258                 return true;
 259         }
 260
 261         if(!to) {
 262                 logger(DEBUG_PROTOCOL, LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 263                                    "DEL_EDGE", c->name, c->hostname);
 264                 return true;
 265         }
 266
 267         /* Check if edge exists */
 268
 269         e = lookup_edge(from, to);
 270
 271         if(!e) {
 272                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) which does not appear in the edge tree",
 273                                    "DEL_EDGE", c->name, c->hostname);
 274                 return true;
 275         }
 276
 277         if(e->from == myself) {
 278                 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself",
 279                                    "DEL_EDGE", c->name, c->hostname);
 280                 contradicting_del_edge++;
 281                 send_add_edge(c, e);    /* Send back a correction */
 282                 return true;
 283         }
 284
 285         /* Tell the rest about the deleted edge */
 286
 287         if(!tunnelserver)
 288                 forward_request(c, request);
 289
 290         /* Delete the edge */
 291
 292         edge_del(e);
 293
 294         /* Run MST before or after we tell the rest? */
 295
 296         graph();
 297
 298         /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 299
 300         if(!to->status.reachable) {
 301                 e = lookup_edge(to, myself);
 302                 if(e) {
 303                         if(!tunnelserver)
 304                                 send_del_edge(everyone, e);
 305                         edge_del(e);
 306                 }
 307         }
 308
 309         return true;
 310 }