git.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                   2000-2016 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) || !strcmp(from_name, 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
  83         /* Lookup nodes */
  84
  85         from = lookup_node(from_name);
  86         to = lookup_node(to_name);
  87
  88         if(tunnelserver &&
  89                         from != myself && from != c->node &&
  90                         to != myself && to != c->node) {
  91                 /* ignore indirect edge registrations for tunnelserver */
  92                 ifdebug(PROTOCOL) logger(LOG_WARNING,
  93                                          "Ignoring indirect %s from %s (%s)",
  94                                          "ADD_EDGE", c->name, c->hostname);
  95                 return true;
  96         }
  97
  98         if(!from) {
  99                 from = new_node();
 100                 from->name = xstrdup(from_name);
 101                 node_add(from);
 102         }
 103
 104         if(!to) {
 105                 to = new_node();
 106                 to->name = xstrdup(to_name);
 107                 node_add(to);
 108         }
 109
 110
 111         /* Convert addresses */
 112
 113         address = str2sockaddr(to_address, to_port);
 114
 115         /* Check if edge already exists */
 116
 117         e = lookup_edge(from, to);
 118
 119         if(e) {
 120                 if(e->weight != weight || e->options != options || sockaddrcmp(&e->address, &address)) {
 121                         if(from == myself) {
 122                                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 123                                                          "ADD_EDGE", c->name, c->hostname);
 124                                 send_add_edge(c, e);
 125                                 return true;
 126                         } else {
 127                                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) which does not match existing entry",
 128                                                          "ADD_EDGE", c->name, c->hostname);
 129                                 e->options = options;
 130
 131                                 if(sockaddrcmp(&e->address, &address)) {
 132                                         sockaddrfree(&e->address);
 133                                         e->address = address;
 134                                 }
 135
 136                                 if(e->weight != weight) {
 137                                         avl_node_t *node = avl_unlink(edge_weight_tree, e);
 138                                         e->weight = weight;
 139                                         avl_insert_node(edge_weight_tree, node);
 140                                 }
 141
 142                                 goto done;
 143                         }
 144                 } else {
 145                         return true;
 146                 }
 147         } else if(from == myself) {
 148                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) for ourself which does not exist",
 149                                          "ADD_EDGE", c->name, c->hostname);
 150                 contradicting_add_edge++;
 151                 e = new_edge();
 152                 e->from = from;
 153                 e->to = to;
 154                 send_del_edge(c, e);
 155                 free_edge(e);
 156                 return true;
 157         }
 158
 159         e = new_edge();
 160         e->from = from;
 161         e->to = to;
 162         e->address = address;
 163         e->options = options;
 164         e->weight = weight;
 165         edge_add(e);
 166
 167 done:
 168         /* Tell the rest about the new edge */
 169
 170         if(!tunnelserver) {
 171                 forward_request(c);
 172         }
 173
 174         /* Run MST before or after we tell the rest? */
 175
 176         graph();
 177
 178         return true;
 179 }
 180
 181 bool send_del_edge(connection_t *c, const edge_t *e) {
 182         return send_request(c, "%d %x %s %s", DEL_EDGE, rand(),
 183                             e->from->name, e->to->name);
 184 }
 185
 186 bool del_edge_h(connection_t *c) {
 187         edge_t *e;
 188         char from_name[MAX_STRING_SIZE];
 189         char to_name[MAX_STRING_SIZE];
 190         node_t *from, *to;
 191
 192         if(sscanf(c->buffer, "%*d %*x "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) {
 193                 logger(LOG_ERR, "Got bad %s from %s (%s)", "DEL_EDGE", c->name,
 194                        c->hostname);
 195                 return false;
 196         }
 197
 198         /* Check if names are valid */
 199
 200         if(!check_id(from_name) || !check_id(to_name) || !strcmp(from_name, to_name)) {
 201                 logger(LOG_ERR, "Got bad %s from %s (%s): %s", "DEL_EDGE", c->name,
 202                        c->hostname, "invalid name");
 203                 return false;
 204         }
 205
 206         if(seen_request(c->buffer)) {
 207                 return true;
 208         }
 209
 210         /* Lookup nodes */
 211
 212         from = lookup_node(from_name);
 213         to = lookup_node(to_name);
 214
 215         if(tunnelserver &&
 216                         from != myself && from != c->node &&
 217                         to != myself && to != c->node) {
 218                 /* ignore indirect edge registrations for tunnelserver */
 219                 ifdebug(PROTOCOL) logger(LOG_WARNING,
 220                                          "Ignoring indirect %s from %s (%s)",
 221                                          "DEL_EDGE", c->name, c->hostname);
 222                 return true;
 223         }
 224
 225         if(!from) {
 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         if(!to) {
 232                 ifdebug(PROTOCOL) logger(LOG_ERR, "Got %s from %s (%s) which does not appear in the edge tree",
 233                                          "DEL_EDGE", c->name, c->hostname);
 234                 return true;
 235         }
 236
 237         /* Check if edge exists */
 238
 239         e = lookup_edge(from, to);
 240
 241         if(!e) {
 242                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) which does not appear in the edge tree",
 243                                          "DEL_EDGE", c->name, c->hostname);
 244                 return true;
 245         }
 246
 247         if(e->from == myself) {
 248                 ifdebug(PROTOCOL) logger(LOG_WARNING, "Got %s from %s (%s) for ourself",
 249                                          "DEL_EDGE", c->name, c->hostname);
 250                 contradicting_del_edge++;
 251                 send_add_edge(c, e);    /* Send back a correction */
 252                 return true;
 253         }
 254
 255         /* Tell the rest about the deleted edge */
 256
 257         if(!tunnelserver) {
 258                 forward_request(c);
 259         }
 260
 261         /* Delete the edge */
 262
 263         edge_del(e);
 264
 265         /* Run MST before or after we tell the rest? */
 266
 267         graph();
 268
 269         /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 270
 271         if(!to->status.reachable) {
 272                 e = lookup_edge(to, myself);
 273
 274                 if(e) {
 275                         if(!tunnelserver) {
 276                                 send_del_edge(everyone, e);
 277                         }
 278
 279                         edge_del(e);
 280                 }
 281         }
 282
 283         return true;
 284 }