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

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000-2010 Guus Sliepen <guus@tinc-vpn.org>,
   4                   2000-2005 Ivo Timmermans
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21 #include "system.h"
  22
  23 #include "avl_tree.h"
  24 #include "device.h"
  25 #include "logger.h"
  26 #include "net.h"
  27 #include "netutl.h"
  28 #include "node.h"
  29 #include "process.h"
  30 #include "subnet.h"
  31 #include "utils.h"
  32 #include "xalloc.h"
  33
  34 /* lists type of subnet */
  35
  36 avl_tree_t *subnet_tree;
  37
  38 /* Subnet lookup cache */
  39
  40 static ipv4_t cache_ipv4_address[2];
  41 static subnet_t *cache_ipv4_subnet[2];
  42 static bool cache_ipv4_valid[2];
  43 static int cache_ipv4_slot;
  44
  45 static ipv6_t cache_ipv6_address[2];
  46 static subnet_t *cache_ipv6_subnet[2];
  47 static bool cache_ipv6_valid[2];
  48 static int cache_ipv6_slot;
  49
  50 static mac_t cache_mac_address[2];
  51 static subnet_t *cache_mac_subnet[2];
  52 static bool cache_mac_valid[2];
  53 static int cache_mac_slot;
  54
  55 void subnet_cache_flush() {
  56         cache_ipv4_valid[0] = cache_ipv4_valid[1] = false;
  57         cache_ipv6_valid[0] = cache_ipv6_valid[1] = false;
  58         cache_mac_valid[0] = cache_mac_valid[1] = false;
  59 }
  60
  61 /* Subnet comparison */
  62
  63 static int subnet_compare_mac(const subnet_t *a, const subnet_t *b) {
  64         int result;
  65
  66         result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
  67
  68         if(result)
  69                 return result;
  70
  71         result = a->weight - b->weight;
  72
  73         if(result || !a->owner || !b->owner)
  74                 return result;
  75
  76         return strcmp(a->owner->name, b->owner->name);
  77 }
  78
  79 static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b) {
  80         int result;
  81
  82         result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
  83
  84         if(result)
  85                 return result;
  86
  87         result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
  88
  89         if(result)
  90                 return result;
  91
  92         result = a->weight - b->weight;
  93
  94         if(result || !a->owner || !b->owner)
  95                 return result;
  96
  97         return strcmp(a->owner->name, b->owner->name);
  98 }
  99
 100 static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b) {
 101         int result;
 102
 103         result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
 104
 105         if(result)
 106                 return result;
 107
 108         result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
 109
 110         if(result)
 111                 return result;
 112
 113         result = a->weight - b->weight;
 114
 115         if(result || !a->owner || !b->owner)
 116                 return result;
 117
 118         return strcmp(a->owner->name, b->owner->name);
 119 }
 120
 121 int subnet_compare(const subnet_t *a, const subnet_t *b) {
 122         int result;
 123
 124         result = a->type - b->type;
 125
 126         if(result)
 127                 return result;
 128
 129         switch (a->type) {
 130         case SUBNET_MAC:
 131                 return subnet_compare_mac(a, b);
 132         case SUBNET_IPV4:
 133                 return subnet_compare_ipv4(a, b);
 134         case SUBNET_IPV6:
 135                 return subnet_compare_ipv6(a, b);
 136         default:
 137                 logger(LOG_ERR, "subnet_compare() was called with unknown subnet type %d, exitting!",
 138                            a->type);
 139                 exit(0);
 140         }
 141
 142         return 0;
 143 }
 144
 145 /* Initialising trees */
 146
 147 void init_subnets(void) {
 148         subnet_tree = avl_alloc_tree((avl_compare_t) subnet_compare, (avl_action_t) free_subnet);
 149
 150         subnet_cache_flush();
 151 }
 152
 153 void exit_subnets(void) {
 154         avl_delete_tree(subnet_tree);
 155 }
 156
 157 avl_tree_t *new_subnet_tree(void) {
 158         return avl_alloc_tree((avl_compare_t) subnet_compare, NULL);
 159 }
 160
 161 void free_subnet_tree(avl_tree_t *subnet_tree) {
 162         avl_delete_tree(subnet_tree);
 163 }
 164
 165 /* Allocating and freeing space for subnets */
 166
 167 subnet_t *new_subnet(void) {
 168         return xmalloc_and_zero(sizeof(subnet_t));
 169 }
 170
 171 void free_subnet(subnet_t *subnet) {
 172         free(subnet);
 173 }
 174
 175 /* Adding and removing subnets */
 176
 177 void subnet_add(node_t *n, subnet_t *subnet) {
 178         subnet->owner = n;
 179
 180         avl_insert(subnet_tree, subnet);
 181         avl_insert(n->subnet_tree, subnet);
 182
 183         subnet_cache_flush();
 184 }
 185
 186 void subnet_del(node_t *n, subnet_t *subnet) {
 187         avl_delete(n->subnet_tree, subnet);
 188         avl_delete(subnet_tree, subnet);
 189
 190         subnet_cache_flush();
 191 }
 192
 193 /* Ascii representation of subnets */
 194
 195 bool str2net(subnet_t *subnet, const char *subnetstr) {
 196         int i, l;
 197         uint16_t x[8];
 198         int weight = 10;
 199
 200         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
 201                           &x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
 202                 if(l < 0 || l > 32)
 203                         return false;
 204
 205                 subnet->type = SUBNET_IPV4;
 206                 subnet->net.ipv4.prefixlength = l;
 207                 subnet->weight = weight;
 208
 209                 for(i = 0; i < 4; i++) {
 210                         if(x[i] > 255)
 211                                 return false;
 212                         subnet->net.ipv4.address.x[i] = x[i];
 213                 }
 214
 215                 return true;
 216         }
 217
 218         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 219                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
 220                           &l, &weight) >= 9) {
 221                 if(l < 0 || l > 128)
 222                         return false;
 223
 224                 subnet->type = SUBNET_IPV6;
 225                 subnet->net.ipv6.prefixlength = l;
 226                 subnet->weight = weight;
 227
 228                 for(i = 0; i < 8; i++)
 229                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 230
 231                 return true;
 232         }
 233
 234         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
 235                 subnet->type = SUBNET_IPV4;
 236                 subnet->net.ipv4.prefixlength = 32;
 237                 subnet->weight = weight;
 238
 239                 for(i = 0; i < 4; i++) {
 240                         if(x[i] > 255)
 241                                 return false;
 242                         subnet->net.ipv4.address.x[i] = x[i];
 243                 }
 244
 245                 return true;
 246         }
 247
 248         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
 249                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
 250                 subnet->type = SUBNET_IPV6;
 251                 subnet->net.ipv6.prefixlength = 128;
 252                 subnet->weight = weight;
 253
 254                 for(i = 0; i < 8; i++)
 255                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 256
 257                 return true;
 258         }
 259
 260         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 261                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
 262                 subnet->type = SUBNET_MAC;
 263                 subnet->weight = weight;
 264
 265                 for(i = 0; i < 6; i++)
 266                         subnet->net.mac.address.x[i] = x[i];
 267
 268                 return true;
 269         }
 270
 271         return false;
 272 }
 273
 274 bool net2str(char *netstr, int len, const subnet_t *subnet) {
 275         if(!netstr || !subnet) {
 276                 logger(LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!\n", netstr, subnet);
 277                 return false;
 278         }
 279
 280         switch (subnet->type) {
 281                 case SUBNET_MAC:
 282                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 283                                          subnet->net.mac.address.x[0],
 284                                          subnet->net.mac.address.x[1],
 285                                          subnet->net.mac.address.x[2],
 286                                          subnet->net.mac.address.x[3],
 287                                          subnet->net.mac.address.x[4],
 288                                          subnet->net.mac.address.x[5],
 289                                          subnet->weight);
 290                         break;
 291
 292                 case SUBNET_IPV4:
 293                         snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
 294                                          subnet->net.ipv4.address.x[0],
 295                                          subnet->net.ipv4.address.x[1],
 296                                          subnet->net.ipv4.address.x[2],
 297                                          subnet->net.ipv4.address.x[3],
 298                                          subnet->net.ipv4.prefixlength,
 299                                          subnet->weight);
 300                         break;
 301
 302                 case SUBNET_IPV6:
 303                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 304                                          ntohs(subnet->net.ipv6.address.x[0]),
 305                                          ntohs(subnet->net.ipv6.address.x[1]),
 306                                          ntohs(subnet->net.ipv6.address.x[2]),
 307                                          ntohs(subnet->net.ipv6.address.x[3]),
 308                                          ntohs(subnet->net.ipv6.address.x[4]),
 309                                          ntohs(subnet->net.ipv6.address.x[5]),
 310                                          ntohs(subnet->net.ipv6.address.x[6]),
 311                                          ntohs(subnet->net.ipv6.address.x[7]),
 312                                          subnet->net.ipv6.prefixlength,
 313                                          subnet->weight);
 314                         break;
 315
 316                 default:
 317                         logger(LOG_ERR,
 318                                    "net2str() was called with unknown subnet type %d, exiting!",
 319                                    subnet->type);
 320                         exit(0);
 321         }
 322
 323         return true;
 324 }
 325
 326 /* Subnet lookup routines */
 327
 328 subnet_t *lookup_subnet(const node_t *owner, const subnet_t *subnet) {
 329         return avl_search(owner->subnet_tree, subnet);
 330 }
 331
 332 subnet_t *lookup_subnet_mac(const node_t *owner, const mac_t *address) {
 333         subnet_t *p, *r = NULL;
 334         avl_node_t *n;
 335         int i;
 336
 337         // Check if this address is cached
 338
 339         for(i = 0; i < 2; i++) {
 340                 if(!cache_mac_valid[i])
 341                         continue;
 342                 if(owner && cache_mac_subnet[i] && cache_mac_subnet[i]->owner != owner)
 343                         continue;
 344                 if(!memcmp(address, &cache_mac_address[i], sizeof *address))
 345                         return cache_mac_subnet[i];
 346         }
 347
 348         // Search all subnets for a matching one
 349
 350         for(n = owner ? owner->subnet_tree->head : subnet_tree->head; n; n = n->next) {
 351                 p = n->data;
 352
 353                 if(!p || p->type != SUBNET_MAC)
 354                         continue;
 355
 356                 if(!memcmp(address, &p->net.mac.address, sizeof *address)) {
 357                         r = p;
 358                         if(p->owner->status.reachable)
 359                                 break;
 360                 }
 361         }
 362
 363         // Cache the result
 364
 365         cache_mac_slot = !cache_mac_slot;
 366         memcpy(&cache_mac_address[cache_mac_slot], address, sizeof *address);
 367         cache_mac_subnet[cache_mac_slot] = r;
 368         cache_mac_valid[cache_mac_slot] = true;
 369
 370         return r;
 371 }
 372
 373 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
 374         subnet_t *p, *r = NULL;
 375         avl_node_t *n;
 376         int i;
 377
 378         // Check if this address is cached
 379
 380         for(i = 0; i < 2; i++) {
 381                 if(!cache_ipv4_valid[i])
 382                         continue;
 383                 if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
 384                         return cache_ipv4_subnet[i];
 385         }
 386
 387         // Search all subnets for a matching one
 388
 389         for(n = subnet_tree->head; n; n = n->next) {
 390                 p = n->data;
 391
 392                 if(!p || p->type != SUBNET_IPV4)
 393                         continue;
 394
 395                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 396                         r = p;
 397                         if(p->owner->status.reachable)
 398                                 break;
 399                 }
 400         }
 401
 402         // Cache the result
 403
 404         cache_ipv4_slot = !cache_ipv4_slot;
 405         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
 406         cache_ipv4_subnet[cache_ipv4_slot] = r;
 407         cache_ipv4_valid[cache_ipv4_slot] = true;
 408
 409         return r;
 410 }
 411
 412 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 413         subnet_t *p, *r = NULL;
 414         avl_node_t *n;
 415         int i;
 416
 417         // Check if this address is cached
 418
 419         for(i = 0; i < 2; i++) {
 420                 if(!cache_ipv6_valid[i])
 421                         continue;
 422                 if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
 423                         return cache_ipv6_subnet[i];
 424         }
 425
 426         // Search all subnets for a matching one
 427
 428         for(n = subnet_tree->head; n; n = n->next) {
 429                 p = n->data;
 430
 431                 if(!p || p->type != SUBNET_IPV6)
 432                         continue;
 433
 434                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 435                         r = p;
 436                         if(p->owner->status.reachable)
 437                                 break;
 438                 }
 439         }
 440
 441         // Cache the result
 442
 443         cache_ipv6_slot = !cache_ipv6_slot;
 444         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
 445         cache_ipv6_subnet[cache_ipv6_slot] = r;
 446         cache_ipv6_valid[cache_ipv6_slot] = true;
 447
 448         return r;
 449 }
 450
 451 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 452         avl_node_t *node;
 453         int i;
 454         char *envp[9] = {0};
 455         char netstr[MAXNETSTR];
 456         char *name, *address, *port;
 457         char empty[] = "";
 458
 459         // Prepare environment variables to be passed to the script
 460
 461         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 462         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 463         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 464         xasprintf(&envp[3], "NODE=%s", owner->name);
 465
 466         if(owner != myself) {
 467                 sockaddr2str(&owner->address, &address, &port);
 468                 // 4 and 5 are reserved for SUBNET and WEIGHT
 469                 xasprintf(&envp[6], "REMOTEADDRESS=%s", address);
 470                 xasprintf(&envp[7], "REMOTEPORT=%s", port);
 471         }
 472
 473         name = up ? "subnet-up" : "subnet-down";
 474
 475         if(!subnet) {
 476                 for(node = owner->subnet_tree->head; node; node = node->next) {
 477                         subnet = node->data;
 478                         if(!net2str(netstr, sizeof netstr, subnet))
 479                                 continue;
 480                         // Strip the weight from the subnet, and put it in its own environment variable
 481                         char *weight = strchr(netstr, '#');
 482                         if(weight)
 483                                 *weight++ = 0;
 484                         else
 485                                 weight = empty;
 486
 487                         // Prepare the SUBNET and WEIGHT variables
 488                         if(envp[4])
 489                                 free(envp[4]);
 490                         if(envp[5])
 491                                 free(envp[5]);
 492                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 493                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 494
 495                         execute_script(name, envp);
 496                 }
 497         } else {
 498                 if(net2str(netstr, sizeof netstr, subnet)) {
 499                         // Strip the weight from the subnet, and put it in its own environment variable
 500                         char *weight = strchr(netstr, '#');
 501                         if(weight)
 502                                 *weight++ = 0;
 503                         else
 504                                 weight = empty;
 505
 506                         // Prepare the SUBNET and WEIGHT variables
 507                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 508                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 509
 510                         execute_script(name, envp);
 511                 }
 512         }
 513
 514         for(i = 0; envp[i] && i < 9; i++)
 515                 free(envp[i]);
 516 }
 517
 518 void dump_subnets(void) {
 519         char netstr[MAXNETSTR];
 520         subnet_t *subnet;
 521         avl_node_t *node;
 522
 523         logger(LOG_DEBUG, "Subnet list:");
 524
 525         for(node = subnet_tree->head; node; node = node->next) {
 526                 subnet = node->data;
 527                 if(!net2str(netstr, sizeof netstr, subnet))
 528                         continue;
 529                 logger(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 530         }
 531
 532         logger(LOG_DEBUG, "End of subnet list.");
 533 }