src/subnet.c

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000-2014 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
  72         result = a->weight - b->weight;
  73
  74         if(result || !a->owner || !b->owner) {
  75                 return result;
  76         }
  77
  78         return strcmp(a->owner->name, b->owner->name);
  79 }
  80
  81 static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b) {
  82         int result;
  83
  84         result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
  85
  86         if(result) {
  87                 return result;
  88         }
  89
  90         result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
  91
  92         if(result) {
  93                 return result;
  94         }
  95
  96         result = a->weight - b->weight;
  97
  98         if(result || !a->owner || !b->owner) {
  99                 return result;
 100         }
 101
 102         return strcmp(a->owner->name, b->owner->name);
 103 }
 104
 105 static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b) {
 106         int result;
 107
 108         result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
 109
 110         if(result) {
 111                 return result;
 112         }
 113
 114         result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
 115
 116         if(result) {
 117                 return result;
 118         }
 119
 120         result = a->weight - b->weight;
 121
 122         if(result || !a->owner || !b->owner) {
 123                 return result;
 124         }
 125
 126         return strcmp(a->owner->name, b->owner->name);
 127 }
 128
 129 int subnet_compare(const subnet_t *a, const subnet_t *b) {
 130         int result;
 131
 132         result = a->type - b->type;
 133
 134         if(result) {
 135                 return result;
 136         }
 137
 138         switch(a->type) {
 139         case SUBNET_MAC:
 140                 return subnet_compare_mac(a, b);
 141
 142         case SUBNET_IPV4:
 143                 return subnet_compare_ipv4(a, b);
 144
 145         case SUBNET_IPV6:
 146                 return subnet_compare_ipv6(a, b);
 147
 148         default:
 149                 logger(LOG_ERR, "subnet_compare() was called with unknown subnet type %d, exitting!",
 150                        a->type);
 151                 exit(0);
 152         }
 153
 154         return 0;
 155 }
 156
 157 /* Initialising trees */
 158
 159 void init_subnets(void) {
 160         subnet_tree = avl_alloc_tree((avl_compare_t) subnet_compare, (avl_action_t) free_subnet);
 161
 162         subnet_cache_flush();
 163 }
 164
 165 void exit_subnets(void) {
 166         avl_delete_tree(subnet_tree);
 167 }
 168
 169 avl_tree_t *new_subnet_tree(void) {
 170         return avl_alloc_tree((avl_compare_t) subnet_compare, NULL);
 171 }
 172
 173 void free_subnet_tree(avl_tree_t *subnet_tree) {
 174         avl_delete_tree(subnet_tree);
 175 }
 176
 177 /* Allocating and freeing space for subnets */
 178
 179 subnet_t *new_subnet(void) {
 180         return xmalloc_and_zero(sizeof(subnet_t));
 181 }
 182
 183 void free_subnet(subnet_t *subnet) {
 184         free(subnet);
 185 }
 186
 187 /* Adding and removing subnets */
 188
 189 void subnet_add(node_t *n, subnet_t *subnet) {
 190         subnet->owner = n;
 191
 192         avl_insert(subnet_tree, subnet);
 193         avl_insert(n->subnet_tree, subnet);
 194
 195         subnet_cache_flush();
 196 }
 197
 198 void subnet_del(node_t *n, subnet_t *subnet) {
 199         avl_delete(n->subnet_tree, subnet);
 200         avl_delete(subnet_tree, subnet);
 201
 202         subnet_cache_flush();
 203 }
 204
 205 /* Ascii representation of subnets */
 206
 207 bool str2net(subnet_t *subnet, const char *subnetstr) {
 208         int i, l;
 209         uint16_t x[8];
 210         int weight = 10;
 211
 212         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
 213                         &x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
 214                 if(l < 0 || l > 32) {
 215                         return false;
 216                 }
 217
 218                 subnet->type = SUBNET_IPV4;
 219                 subnet->net.ipv4.prefixlength = l;
 220                 subnet->weight = weight;
 221
 222                 for(i = 0; i < 4; i++) {
 223                         if(x[i] > 255) {
 224                                 return false;
 225                         }
 226
 227                         subnet->net.ipv4.address.x[i] = x[i];
 228                 }
 229
 230                 return true;
 231         }
 232
 233         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 234                         &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
 235                         &l, &weight) >= 9) {
 236                 if(l < 0 || l > 128) {
 237                         return false;
 238                 }
 239
 240                 subnet->type = SUBNET_IPV6;
 241                 subnet->net.ipv6.prefixlength = l;
 242                 subnet->weight = weight;
 243
 244                 for(i = 0; i < 8; i++) {
 245                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 246                 }
 247
 248                 return true;
 249         }
 250
 251         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
 252                 subnet->type = SUBNET_IPV4;
 253                 subnet->net.ipv4.prefixlength = 32;
 254                 subnet->weight = weight;
 255
 256                 for(i = 0; i < 4; i++) {
 257                         if(x[i] > 255) {
 258                                 return false;
 259                         }
 260
 261                         subnet->net.ipv4.address.x[i] = x[i];
 262                 }
 263
 264                 return true;
 265         }
 266
 267         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
 268                         &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
 269                 subnet->type = SUBNET_IPV6;
 270                 subnet->net.ipv6.prefixlength = 128;
 271                 subnet->weight = weight;
 272
 273                 for(i = 0; i < 8; i++) {
 274                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 275                 }
 276
 277                 return true;
 278         }
 279
 280         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 281                         &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
 282                 subnet->type = SUBNET_MAC;
 283                 subnet->weight = weight;
 284
 285                 for(i = 0; i < 6; i++) {
 286                         subnet->net.mac.address.x[i] = x[i];
 287                 }
 288
 289                 return true;
 290         }
 291
 292         // IPv6 short form
 293         if(strstr(subnetstr, "::")) {
 294                 const char *p;
 295                 char *q;
 296                 int colons = 0;
 297
 298                 // Count number of colons
 299                 for(p = subnetstr; *p; p++)
 300                         if(*p == ':') {
 301                                 colons++;
 302                         }
 303
 304                 if(colons > 7) {
 305                         return false;
 306                 }
 307
 308                 // Scan numbers before the double colon
 309                 p = subnetstr;
 310
 311                 for(i = 0; i < colons; i++) {
 312                         if(*p == ':') {
 313                                 break;
 314                         }
 315
 316                         x[i] = strtoul(p, &q, 0x10);
 317
 318                         if(!q || p == q || *q != ':') {
 319                                 return false;
 320                         }
 321
 322                         p = ++q;
 323                 }
 324
 325                 p++;
 326                 colons -= i;
 327
 328                 if(!i) {
 329                         p++;
 330                         colons--;
 331                 }
 332
 333                 if(!*p || *p == '/' || *p == '#') {
 334                         colons--;
 335                 }
 336
 337                 // Fill in the blanks
 338                 for(; i < 8 - colons; i++) {
 339                         x[i] = 0;
 340                 }
 341
 342                 // Scan the remaining numbers
 343                 for(; i < 8; i++) {
 344                         x[i] = strtoul(p, &q, 0x10);
 345
 346                         if(!q || p == q) {
 347                                 return false;
 348                         }
 349
 350                         if(i == 7) {
 351                                 p = q;
 352                                 break;
 353                         }
 354
 355                         if(*q != ':') {
 356                                 return false;
 357                         }
 358
 359                         p = ++q;
 360                 }
 361
 362                 l = 128;
 363
 364                 if(*p == '/') {
 365                         sscanf(p, "/%d#%d", &l, &weight);
 366                 } else if(*p == '#') {
 367                         sscanf(p, "#%d", &weight);
 368                 }
 369
 370                 if(l < 0 || l > 128) {
 371                         return false;
 372                 }
 373
 374                 subnet->type = SUBNET_IPV6;
 375                 subnet->net.ipv6.prefixlength = l;
 376                 subnet->weight = weight;
 377
 378                 for(i = 0; i < 8; i++) {
 379                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 380                 }
 381
 382                 return true;
 383         }
 384
 385         return false;
 386 }
 387
 388 bool net2str(char *netstr, int len, const subnet_t *subnet) {
 389         if(!netstr || !subnet) {
 390                 logger(LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!", (void *)netstr, (void *)subnet);
 391                 return false;
 392         }
 393
 394         switch(subnet->type) {
 395         case SUBNET_MAC:
 396                 snprintf(netstr, len, "%x:%x:%x:%x:%x:%x#%d",
 397                          subnet->net.mac.address.x[0],
 398                          subnet->net.mac.address.x[1],
 399                          subnet->net.mac.address.x[2],
 400                          subnet->net.mac.address.x[3],
 401                          subnet->net.mac.address.x[4],
 402                          subnet->net.mac.address.x[5],
 403                          subnet->weight);
 404                 break;
 405
 406         case SUBNET_IPV4:
 407                 snprintf(netstr, len, "%u.%u.%u.%u/%d#%d",
 408                          subnet->net.ipv4.address.x[0],
 409                          subnet->net.ipv4.address.x[1],
 410                          subnet->net.ipv4.address.x[2],
 411                          subnet->net.ipv4.address.x[3],
 412                          subnet->net.ipv4.prefixlength,
 413                          subnet->weight);
 414                 break;
 415
 416         case SUBNET_IPV6:
 417                 snprintf(netstr, len, "%x:%x:%x:%x:%x:%x:%x:%x/%d#%d",
 418                          ntohs(subnet->net.ipv6.address.x[0]),
 419                          ntohs(subnet->net.ipv6.address.x[1]),
 420                          ntohs(subnet->net.ipv6.address.x[2]),
 421                          ntohs(subnet->net.ipv6.address.x[3]),
 422                          ntohs(subnet->net.ipv6.address.x[4]),
 423                          ntohs(subnet->net.ipv6.address.x[5]),
 424                          ntohs(subnet->net.ipv6.address.x[6]),
 425                          ntohs(subnet->net.ipv6.address.x[7]),
 426                          subnet->net.ipv6.prefixlength,
 427                          subnet->weight);
 428                 break;
 429
 430         default:
 431                 logger(LOG_ERR,
 432                        "net2str() was called with unknown subnet type %d, exiting!",
 433                        subnet->type);
 434                 exit(0);
 435         }
 436
 437         return true;
 438 }
 439
 440 /* Subnet lookup routines */
 441
 442 subnet_t *lookup_subnet(const node_t *owner, const subnet_t *subnet) {
 443         return avl_search(owner->subnet_tree, subnet);
 444 }
 445
 446 subnet_t *lookup_subnet_mac(const node_t *owner, const mac_t *address) {
 447         subnet_t *p, *r = NULL;
 448         avl_node_t *n;
 449         int i;
 450
 451         // Check if this address is cached
 452
 453         for(i = 0; i < 2; i++) {
 454                 if(!cache_mac_valid[i]) {
 455                         continue;
 456                 }
 457
 458                 if(owner && cache_mac_subnet[i] && cache_mac_subnet[i]->owner != owner) {
 459                         continue;
 460                 }
 461
 462                 if(!memcmp(address, &cache_mac_address[i], sizeof(*address))) {
 463                         return cache_mac_subnet[i];
 464                 }
 465         }
 466
 467         // Search all subnets for a matching one
 468
 469         for(n = owner ? owner->subnet_tree->head : subnet_tree->head; n; n = n->next) {
 470                 p = n->data;
 471
 472                 if(!p || p->type != SUBNET_MAC) {
 473                         continue;
 474                 }
 475
 476                 if(!memcmp(address, &p->net.mac.address, sizeof(*address))) {
 477                         r = p;
 478
 479                         if(p->owner->status.reachable) {
 480                                 break;
 481                         }
 482                 }
 483         }
 484
 485         // Cache the result
 486
 487         cache_mac_slot = !cache_mac_slot;
 488         memcpy(&cache_mac_address[cache_mac_slot], address, sizeof(*address));
 489         cache_mac_subnet[cache_mac_slot] = r;
 490         cache_mac_valid[cache_mac_slot] = true;
 491
 492         return r;
 493 }
 494
 495 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
 496         subnet_t *p, *r = NULL;
 497         avl_node_t *n;
 498         int i;
 499
 500         // Check if this address is cached
 501
 502         for(i = 0; i < 2; i++) {
 503                 if(!cache_ipv4_valid[i]) {
 504                         continue;
 505                 }
 506
 507                 if(!memcmp(address, &cache_ipv4_address[i], sizeof(*address))) {
 508                         return cache_ipv4_subnet[i];
 509                 }
 510         }
 511
 512         // Search all subnets for a matching one
 513
 514         for(n = subnet_tree->head; n; n = n->next) {
 515                 p = n->data;
 516
 517                 if(!p || p->type != SUBNET_IPV4) {
 518                         continue;
 519                 }
 520
 521                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 522                         r = p;
 523
 524                         if(p->owner->status.reachable) {
 525                                 break;
 526                         }
 527                 }
 528         }
 529
 530         // Cache the result
 531
 532         cache_ipv4_slot = !cache_ipv4_slot;
 533         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof(*address));
 534         cache_ipv4_subnet[cache_ipv4_slot] = r;
 535         cache_ipv4_valid[cache_ipv4_slot] = true;
 536
 537         return r;
 538 }
 539
 540 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 541         subnet_t *p, *r = NULL;
 542         avl_node_t *n;
 543         int i;
 544
 545         // Check if this address is cached
 546
 547         for(i = 0; i < 2; i++) {
 548                 if(!cache_ipv6_valid[i]) {
 549                         continue;
 550                 }
 551
 552                 if(!memcmp(address, &cache_ipv6_address[i], sizeof(*address))) {
 553                         return cache_ipv6_subnet[i];
 554                 }
 555         }
 556
 557         // Search all subnets for a matching one
 558
 559         for(n = subnet_tree->head; n; n = n->next) {
 560                 p = n->data;
 561
 562                 if(!p || p->type != SUBNET_IPV6) {
 563                         continue;
 564                 }
 565
 566                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 567                         r = p;
 568
 569                         if(p->owner->status.reachable) {
 570                                 break;
 571                         }
 572                 }
 573         }
 574
 575         // Cache the result
 576
 577         cache_ipv6_slot = !cache_ipv6_slot;
 578         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof(*address));
 579         cache_ipv6_subnet[cache_ipv6_slot] = r;
 580         cache_ipv6_valid[cache_ipv6_slot] = true;
 581
 582         return r;
 583 }
 584
 585 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 586         avl_node_t *node;
 587         int i;
 588         char *envp[10] = {NULL};
 589         char netstr[MAXNETSTR];
 590         char *name, *address, *port;
 591         char empty[] = "";
 592
 593         // Prepare environment variables to be passed to the script
 594
 595         xasprintf(&envp[0], "NETNAME=%s", netname ? netname : "");
 596         xasprintf(&envp[1], "DEVICE=%s", device ? device : "");
 597         xasprintf(&envp[2], "INTERFACE=%s", iface ? iface : "");
 598         xasprintf(&envp[3], "NODE=%s", owner->name);
 599         xasprintf(&envp[4], "NAME=%s", myself->name);
 600
 601         if(owner != myself) {
 602                 sockaddr2str(&owner->address, &address, &port);
 603                 // 5 and 6 are reserved for SUBNET and WEIGHT
 604                 xasprintf(&envp[7], "REMOTEADDRESS=%s", address);
 605                 xasprintf(&envp[8], "REMOTEPORT=%s", port);
 606                 free(port);
 607                 free(address);
 608         }
 609
 610         name = up ? "subnet-up" : "subnet-down";
 611
 612         if(!subnet) {
 613                 for(node = owner->subnet_tree->head; node; node = node->next) {
 614                         subnet = node->data;
 615
 616                         if(!net2str(netstr, sizeof(netstr), subnet)) {
 617                                 continue;
 618                         }
 619
 620                         // Strip the weight from the subnet, and put it in its own environment variable
 621                         char *weight = strchr(netstr, '#');
 622
 623                         if(weight) {
 624                                 *weight++ = 0;
 625                         } else {
 626                                 weight = empty;
 627                         }
 628
 629                         // Prepare the SUBNET and WEIGHT variables
 630                         if(envp[5]) {
 631                                 free(envp[5]);
 632                         }
 633
 634                         if(envp[6]) {
 635                                 free(envp[6]);
 636                         }
 637
 638                         xasprintf(&envp[5], "SUBNET=%s", netstr);
 639                         xasprintf(&envp[6], "WEIGHT=%s", weight);
 640
 641                         execute_script(name, envp);
 642                 }
 643         } else {
 644                 if(net2str(netstr, sizeof(netstr), subnet)) {
 645                         // Strip the weight from the subnet, and put it in its own environment variable
 646                         char *weight = strchr(netstr, '#');
 647
 648                         if(weight) {
 649                                 *weight++ = 0;
 650                         } else {
 651                                 weight = empty;
 652                         }
 653
 654                         // Prepare the SUBNET and WEIGHT variables
 655                         xasprintf(&envp[5], "SUBNET=%s", netstr);
 656                         xasprintf(&envp[6], "WEIGHT=%s", weight);
 657
 658                         execute_script(name, envp);
 659                 }
 660         }
 661
 662         for(i = 0; envp[i] && i < 9; i++) {
 663                 free(envp[i]);
 664         }
 665 }
 666
 667 void dump_subnets(void) {
 668         char netstr[MAXNETSTR];
 669         subnet_t *subnet;
 670         avl_node_t *node;
 671
 672         logger(LOG_DEBUG, "Subnet list:");
 673
 674         for(node = subnet_tree->head; node; node = node->next) {
 675                 subnet = node->data;
 676
 677                 if(!net2str(netstr, sizeof(netstr), subnet)) {
 678                         continue;
 679                 }
 680
 681                 logger(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 682         }
 683
 684         logger(LOG_DEBUG, "End of subnet list.");
 685 }