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

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000-2013 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(void) {
  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         // IPv6 short form
 272         if(strstr(subnetstr, "::")) {
 273                 const char *p;
 274                 char *q;
 275                 int colons = 0;
 276
 277                 // Count number of colons
 278                 for(p = subnetstr; *p; p++)
 279                         if(*p == ':')
 280                                 colons++;
 281
 282                 if(colons > 7)
 283                         return false;
 284
 285                 // Scan numbers before the double colon
 286                 p = subnetstr;
 287                 for(i = 0; i < colons; i++) {
 288                         if(*p == ':')
 289                                 break;
 290                         x[i] = strtoul(p, &q, 0x10);
 291                         if(!q || p == q || *q != ':')
 292                                 return false;
 293                         p = ++q;
 294                 }
 295
 296                 p++;
 297                 colons -= i;
 298                 if(!i) {
 299                         p++;
 300                         colons--;
 301                 }
 302
 303                 if(!*p || *p == '/' || *p == '#')
 304                         colons--;
 305
 306                 // Fill in the blanks
 307                 for(; i < 8 - colons; i++)
 308                         x[i] = 0;
 309
 310                 // Scan the remaining numbers
 311                 for(; i < 8; i++) {
 312                         x[i] = strtoul(p, &q, 0x10);
 313                         if(!q || p == q)
 314                                 return false;
 315                         if(i == 7) {
 316                                 p = q;
 317                                 break;
 318                         }
 319                         if(*q != ':')
 320                                 return false;
 321                         p = ++q;
 322                 }
 323
 324                 l = 128;
 325                 if(*p == '/')
 326                         sscanf(p, "/%d#%d", &l, &weight);
 327                 else if(*p == '#')
 328                         sscanf(p, "#%d", &weight);
 329
 330                 if(l < 0 || l > 128)
 331                         return false;
 332
 333                 subnet->type = SUBNET_IPV6;
 334                 subnet->net.ipv6.prefixlength = l;
 335                 subnet->weight = weight;
 336
 337                 for(i = 0; i < 8; i++)
 338                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 339
 340                 return true;
 341         }
 342
 343         return false;
 344 }
 345
 346 bool net2str(char *netstr, int len, const subnet_t *subnet) {
 347         if(!netstr || !subnet) {
 348                 logger(LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!", netstr, subnet);
 349                 return false;
 350         }
 351
 352         switch (subnet->type) {
 353                 case SUBNET_MAC:
 354                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 355                                          subnet->net.mac.address.x[0],
 356                                          subnet->net.mac.address.x[1],
 357                                          subnet->net.mac.address.x[2],
 358                                          subnet->net.mac.address.x[3],
 359                                          subnet->net.mac.address.x[4],
 360                                          subnet->net.mac.address.x[5],
 361                                          subnet->weight);
 362                         break;
 363
 364                 case SUBNET_IPV4:
 365                         snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
 366                                          subnet->net.ipv4.address.x[0],
 367                                          subnet->net.ipv4.address.x[1],
 368                                          subnet->net.ipv4.address.x[2],
 369                                          subnet->net.ipv4.address.x[3],
 370                                          subnet->net.ipv4.prefixlength,
 371                                          subnet->weight);
 372                         break;
 373
 374                 case SUBNET_IPV6:
 375                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 376                                          ntohs(subnet->net.ipv6.address.x[0]),
 377                                          ntohs(subnet->net.ipv6.address.x[1]),
 378                                          ntohs(subnet->net.ipv6.address.x[2]),
 379                                          ntohs(subnet->net.ipv6.address.x[3]),
 380                                          ntohs(subnet->net.ipv6.address.x[4]),
 381                                          ntohs(subnet->net.ipv6.address.x[5]),
 382                                          ntohs(subnet->net.ipv6.address.x[6]),
 383                                          ntohs(subnet->net.ipv6.address.x[7]),
 384                                          subnet->net.ipv6.prefixlength,
 385                                          subnet->weight);
 386                         break;
 387
 388                 default:
 389                         logger(LOG_ERR,
 390                                    "net2str() was called with unknown subnet type %d, exiting!",
 391                                    subnet->type);
 392                         exit(0);
 393         }
 394
 395         return true;
 396 }
 397
 398 /* Subnet lookup routines */
 399
 400 subnet_t *lookup_subnet(const node_t *owner, const subnet_t *subnet) {
 401         return avl_search(owner->subnet_tree, subnet);
 402 }
 403
 404 subnet_t *lookup_subnet_mac(const node_t *owner, const mac_t *address) {
 405         subnet_t *p, *r = NULL;
 406         avl_node_t *n;
 407         int i;
 408
 409         // Check if this address is cached
 410
 411         for(i = 0; i < 2; i++) {
 412                 if(!cache_mac_valid[i])
 413                         continue;
 414                 if(owner && cache_mac_subnet[i] && cache_mac_subnet[i]->owner != owner)
 415                         continue;
 416                 if(!memcmp(address, &cache_mac_address[i], sizeof *address))
 417                         return cache_mac_subnet[i];
 418         }
 419
 420         // Search all subnets for a matching one
 421
 422         for(n = owner ? owner->subnet_tree->head : subnet_tree->head; n; n = n->next) {
 423                 p = n->data;
 424
 425                 if(!p || p->type != SUBNET_MAC)
 426                         continue;
 427
 428                 if(!memcmp(address, &p->net.mac.address, sizeof *address)) {
 429                         r = p;
 430                         if(p->owner->status.reachable)
 431                                 break;
 432                 }
 433         }
 434
 435         // Cache the result
 436
 437         cache_mac_slot = !cache_mac_slot;
 438         memcpy(&cache_mac_address[cache_mac_slot], address, sizeof *address);
 439         cache_mac_subnet[cache_mac_slot] = r;
 440         cache_mac_valid[cache_mac_slot] = true;
 441
 442         return r;
 443 }
 444
 445 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
 446         subnet_t *p, *r = NULL;
 447         avl_node_t *n;
 448         int i;
 449
 450         // Check if this address is cached
 451
 452         for(i = 0; i < 2; i++) {
 453                 if(!cache_ipv4_valid[i])
 454                         continue;
 455                 if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
 456                         return cache_ipv4_subnet[i];
 457         }
 458
 459         // Search all subnets for a matching one
 460
 461         for(n = subnet_tree->head; n; n = n->next) {
 462                 p = n->data;
 463
 464                 if(!p || p->type != SUBNET_IPV4)
 465                         continue;
 466
 467                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 468                         r = p;
 469                         if(p->owner->status.reachable)
 470                                 break;
 471                 }
 472         }
 473
 474         // Cache the result
 475
 476         cache_ipv4_slot = !cache_ipv4_slot;
 477         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
 478         cache_ipv4_subnet[cache_ipv4_slot] = r;
 479         cache_ipv4_valid[cache_ipv4_slot] = true;
 480
 481         return r;
 482 }
 483
 484 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 485         subnet_t *p, *r = NULL;
 486         avl_node_t *n;
 487         int i;
 488
 489         // Check if this address is cached
 490
 491         for(i = 0; i < 2; i++) {
 492                 if(!cache_ipv6_valid[i])
 493                         continue;
 494                 if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
 495                         return cache_ipv6_subnet[i];
 496         }
 497
 498         // Search all subnets for a matching one
 499
 500         for(n = subnet_tree->head; n; n = n->next) {
 501                 p = n->data;
 502
 503                 if(!p || p->type != SUBNET_IPV6)
 504                         continue;
 505
 506                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 507                         r = p;
 508                         if(p->owner->status.reachable)
 509                                 break;
 510                 }
 511         }
 512
 513         // Cache the result
 514
 515         cache_ipv6_slot = !cache_ipv6_slot;
 516         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
 517         cache_ipv6_subnet[cache_ipv6_slot] = r;
 518         cache_ipv6_valid[cache_ipv6_slot] = true;
 519
 520         return r;
 521 }
 522
 523 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 524         avl_node_t *node;
 525         int i;
 526         char *envp[10] = {NULL};
 527         char netstr[MAXNETSTR];
 528         char *name, *address, *port;
 529         char empty[] = "";
 530
 531         // Prepare environment variables to be passed to the script
 532
 533         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 534         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 535         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 536         xasprintf(&envp[3], "NODE=%s", owner->name);
 537
 538         if(owner != myself) {
 539                 sockaddr2str(&owner->address, &address, &port);
 540                 // 4 and 5 are reserved for SUBNET and WEIGHT
 541                 xasprintf(&envp[6], "REMOTEADDRESS=%s", address);
 542                 xasprintf(&envp[7], "REMOTEPORT=%s", port);
 543                 free(port);
 544                 free(address);
 545         }
 546
 547         xasprintf(&envp[8], "NAME=%s", myself->name);
 548
 549         name = up ? "subnet-up" : "subnet-down";
 550
 551         if(!subnet) {
 552                 for(node = owner->subnet_tree->head; node; node = node->next) {
 553                         subnet = node->data;
 554                         if(!net2str(netstr, sizeof netstr, subnet))
 555                                 continue;
 556                         // Strip the weight from the subnet, and put it in its own environment variable
 557                         char *weight = strchr(netstr, '#');
 558                         if(weight)
 559                                 *weight++ = 0;
 560                         else
 561                                 weight = empty;
 562
 563                         // Prepare the SUBNET and WEIGHT variables
 564                         if(envp[4])
 565                                 free(envp[4]);
 566                         if(envp[5])
 567                                 free(envp[5]);
 568                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 569                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 570
 571                         execute_script(name, envp);
 572                 }
 573         } else {
 574                 if(net2str(netstr, sizeof netstr, subnet)) {
 575                         // Strip the weight from the subnet, and put it in its own environment variable
 576                         char *weight = strchr(netstr, '#');
 577                         if(weight)
 578                                 *weight++ = 0;
 579                         else
 580                                 weight = empty;
 581
 582                         // Prepare the SUBNET and WEIGHT variables
 583                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 584                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 585
 586                         execute_script(name, envp);
 587                 }
 588         }
 589
 590         for(i = 0; envp[i] && i < 9; i++)
 591                 free(envp[i]);
 592 }
 593
 594 void dump_subnets(void) {
 595         char netstr[MAXNETSTR];
 596         subnet_t *subnet;
 597         avl_node_t *node;
 598
 599         logger(LOG_DEBUG, "Subnet list:");
 600
 601         for(node = subnet_tree->head; node; node = node->next) {
 602                 subnet = node->data;
 603                 if(!net2str(netstr, sizeof netstr, subnet))
 604                         continue;
 605                 logger(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 606         }
 607
 608         logger(LOG_DEBUG, "End of subnet list.");
 609 }