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

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000-2009 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 mac_t *address) {
 333         subnet_t *p, *r = NULL, subnet = {0};
 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(!memcmp(address, &cache_mac_address[i], sizeof *address))
 343                         return cache_mac_subnet[i];
 344         }
 345
 346         // Search all subnets for a matching one
 347
 348         subnet.type = SUBNET_MAC;
 349         subnet.net.mac.address = *address;
 350         subnet.owner = NULL;
 351
 352         for(n = subnet_tree->head; n; n = n->next) {
 353                 p = n->data;
 354
 355                 if(!p || p->type != subnet.type)
 356                         continue;
 357
 358                 if(!memcmp(address, &p->net.mac.address, sizeof *address)) {
 359                         r = p;
 360                         if(p->owner->status.reachable)
 361                                 break;
 362                 }
 363         }
 364
 365         // Cache the result
 366
 367         cache_mac_slot = !cache_mac_slot;
 368         memcpy(&cache_mac_address[cache_mac_slot], address, sizeof *address);
 369         cache_mac_subnet[cache_mac_slot] = r;
 370         cache_mac_valid[cache_mac_slot] = true;
 371
 372         return r;
 373 }
 374
 375 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
 376         subnet_t *p, *r = NULL, subnet = {0};
 377         avl_node_t *n;
 378         int i;
 379
 380         // Check if this address is cached
 381
 382         for(i = 0; i < 2; i++) {
 383                 if(!cache_ipv4_valid[i])
 384                         continue;
 385                 if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
 386                         return cache_ipv4_subnet[i];
 387         }
 388
 389         // Search all subnets for a matching one
 390
 391         subnet.type = SUBNET_IPV4;
 392         subnet.net.ipv4.address = *address;
 393         subnet.net.ipv4.prefixlength = 32;
 394         subnet.owner = NULL;
 395
 396         for(n = subnet_tree->head; n; n = n->next) {
 397                 p = n->data;
 398
 399                 if(!p || p->type != subnet.type)
 400                         continue;
 401
 402                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 403                         r = p;
 404                         if(p->owner->status.reachable)
 405                                 break;
 406                 }
 407         }
 408
 409         // Cache the result
 410
 411         cache_ipv4_slot = !cache_ipv4_slot;
 412         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
 413         cache_ipv4_subnet[cache_ipv4_slot] = r;
 414         cache_ipv4_valid[cache_ipv4_slot] = true;
 415
 416         return r;
 417 }
 418
 419 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 420         subnet_t *p, *r = NULL, subnet = {0};
 421         avl_node_t *n;
 422         int i;
 423
 424         // Check if this address is cached
 425
 426         for(i = 0; i < 2; i++) {
 427                 if(!cache_ipv6_valid[i])
 428                         continue;
 429                 if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
 430                         return cache_ipv6_subnet[i];
 431         }
 432
 433         // Search all subnets for a matching one
 434
 435         subnet.type = SUBNET_IPV6;
 436         subnet.net.ipv6.address = *address;
 437         subnet.net.ipv6.prefixlength = 128;
 438         subnet.owner = NULL;
 439
 440         for(n = subnet_tree->head; n; n = n->next) {
 441                 p = n->data;
 442
 443                 if(!p || p->type != subnet.type)
 444                         continue;
 445
 446                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 447                         r = p;
 448                         if(p->owner->status.reachable)
 449                                 break;
 450                 }
 451         }
 452
 453         // Cache the result
 454
 455         cache_ipv6_slot = !cache_ipv6_slot;
 456         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
 457         cache_ipv6_subnet[cache_ipv6_slot] = r;
 458         cache_ipv6_valid[cache_ipv6_slot] = true;
 459
 460         return r;
 461 }
 462
 463 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 464         avl_node_t *node;
 465         int i;
 466         char *envp[9] = {0};
 467         char netstr[MAXNETSTR];
 468         char *name, *address, *port;
 469         char empty[] = "";
 470
 471         // Prepare environment variables to be passed to the script
 472
 473         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 474         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 475         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 476         xasprintf(&envp[3], "NODE=%s", owner->name);
 477
 478         if(owner != myself) {
 479                 sockaddr2str(&owner->address, &address, &port);
 480                 // 4 and 5 are reserved for SUBNET and WEIGHT
 481                 xasprintf(&envp[6], "REMOTEADDRESS=%s", address);
 482                 xasprintf(&envp[7], "REMOTEPORT=%s", port);
 483         }
 484
 485         name = up ? "subnet-up" : "subnet-down";
 486
 487         if(!subnet) {
 488                 for(node = owner->subnet_tree->head; node; node = node->next) {
 489                         subnet = node->data;
 490                         if(!net2str(netstr, sizeof netstr, subnet))
 491                                 continue;
 492                         // Strip the weight from the subnet, and put it in its own environment variable
 493                         char *weight = strchr(netstr + 7, '#');
 494                         if(weight)
 495                                 *weight++ = 0;
 496                         else
 497                                 weight = empty;
 498
 499                         // Prepare the SUBNET and WEIGHT variables
 500                         if(envp[4])
 501                                 free(envp[4]);
 502                         if(envp[5])
 503                                 free(envp[5]);
 504                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 505                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 506
 507                         execute_script(name, envp);
 508                 }
 509         } else {
 510                 if(net2str(netstr + 7, sizeof netstr - 7, subnet)) {
 511                         // Strip the weight from the subnet, and put it in its own environment variable
 512                         char *weight = strchr(netstr + 7, '#');
 513                         if(weight)
 514                                 *weight++ = 0;
 515                         else
 516                                 weight = empty;
 517
 518                         // Prepare the SUBNET and WEIGHT variables
 519                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 520                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 521
 522                         execute_script(name, envp);
 523                 }
 524         }
 525
 526         for(i = 0; envp[i] && i < 9; i++)
 527                 free(envp[i]);
 528 }
 529
 530 void dump_subnets(void) {
 531         char netstr[MAXNETSTR];
 532         subnet_t *subnet;
 533         avl_node_t *node;
 534
 535         logger(LOG_DEBUG, "Subnet list:");
 536
 537         for(node = subnet_tree->head; node; node = node->next) {
 538                 subnet = node->data;
 539                 if(!net2str(netstr, sizeof netstr, subnet))
 540                         continue;
 541                 logger(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 542         }
 543
 544         logger(LOG_DEBUG, "End of subnet list.");
 545 }