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 void subnet_cache_flush() {
  51         cache_ipv4_valid[0] = cache_ipv4_valid[1] = false;
  52         cache_ipv6_valid[0] = cache_ipv6_valid[1] = false;
  53 }
  54
  55 /* Subnet comparison */
  56
  57 static int subnet_compare_mac(const subnet_t *a, const subnet_t *b)
  58 {
  59         int result;
  60
  61         result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
  62
  63         if(result)
  64                 return result;
  65
  66         result = a->weight - b->weight;
  67
  68         if(result || !a->owner || !b->owner)
  69                 return result;
  70
  71         return strcmp(a->owner->name, b->owner->name);
  72 }
  73
  74 static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b)
  75 {
  76         int result;
  77
  78         result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
  79
  80         if(result)
  81                 return result;
  82
  83         result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
  84
  85         if(result)
  86                 return result;
  87
  88         result = a->weight - b->weight;
  89
  90         if(result || !a->owner || !b->owner)
  91                 return result;
  92
  93         return strcmp(a->owner->name, b->owner->name);
  94 }
  95
  96 static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b)
  97 {
  98         int result;
  99
 100         result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
 101
 102         if(result)
 103                 return result;
 104
 105         result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
 106
 107         if(result)
 108                 return result;
 109
 110         result = a->weight - b->weight;
 111
 112         if(result || !a->owner || !b->owner)
 113                 return result;
 114
 115         return strcmp(a->owner->name, b->owner->name);
 116 }
 117
 118 int subnet_compare(const subnet_t *a, const subnet_t *b)
 119 {
 120         int result;
 121
 122         result = a->type - b->type;
 123
 124         if(result)
 125                 return result;
 126
 127         switch (a->type) {
 128         case SUBNET_MAC:
 129                 return subnet_compare_mac(a, b);
 130         case SUBNET_IPV4:
 131                 return subnet_compare_ipv4(a, b);
 132         case SUBNET_IPV6:
 133                 return subnet_compare_ipv6(a, b);
 134         default:
 135                 logger(LOG_ERR, _("subnet_compare() was called with unknown subnet type %d, exitting!"),
 136                            a->type);
 137                 cp_trace();
 138                 exit(0);
 139         }
 140
 141         return 0;
 142 }
 143
 144 /* Initialising trees */
 145
 146 void init_subnets(void)
 147 {
 148         cp();
 149
 150         subnet_tree = avl_alloc_tree((avl_compare_t) subnet_compare, (avl_action_t) free_subnet);
 151
 152         subnet_cache_flush();
 153 }
 154
 155 void exit_subnets(void)
 156 {
 157         cp();
 158
 159         avl_delete_tree(subnet_tree);
 160 }
 161
 162 avl_tree_t *new_subnet_tree(void)
 163 {
 164         cp();
 165
 166         return avl_alloc_tree((avl_compare_t) subnet_compare, NULL);
 167 }
 168
 169 void free_subnet_tree(avl_tree_t *subnet_tree)
 170 {
 171         cp();
 172
 173         avl_delete_tree(subnet_tree);
 174 }
 175
 176 /* Allocating and freeing space for subnets */
 177
 178 subnet_t *new_subnet(void)
 179 {
 180         cp();
 181
 182         return xmalloc_and_zero(sizeof(subnet_t));
 183 }
 184
 185 void free_subnet(subnet_t *subnet)
 186 {
 187         cp();
 188
 189         free(subnet);
 190 }
 191
 192 /* Adding and removing subnets */
 193
 194 void subnet_add(node_t *n, subnet_t *subnet)
 195 {
 196         cp();
 197
 198         subnet->owner = n;
 199
 200         avl_insert(subnet_tree, subnet);
 201         avl_insert(n->subnet_tree, subnet);
 202
 203         subnet_cache_flush();
 204 }
 205
 206 void subnet_del(node_t *n, subnet_t *subnet)
 207 {
 208         cp();
 209
 210         avl_delete(n->subnet_tree, subnet);
 211         avl_delete(subnet_tree, subnet);
 212
 213         subnet_cache_flush();
 214 }
 215
 216 /* Ascii representation of subnets */
 217
 218 bool str2net(subnet_t *subnet, const char *subnetstr)
 219 {
 220         int i, l;
 221         uint16_t x[8];
 222         int weight = 10;
 223
 224         cp();
 225
 226         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
 227                           &x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
 228                 if(l < 0 || l > 32)
 229                         return false;
 230
 231                 subnet->type = SUBNET_IPV4;
 232                 subnet->net.ipv4.prefixlength = l;
 233                 subnet->weight = weight;
 234
 235                 for(i = 0; i < 4; i++) {
 236                         if(x[i] > 255)
 237                                 return false;
 238                         subnet->net.ipv4.address.x[i] = x[i];
 239                 }
 240
 241                 return true;
 242         }
 243
 244         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 245                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
 246                           &l, &weight) >= 9) {
 247                 if(l < 0 || l > 128)
 248                         return false;
 249
 250                 subnet->type = SUBNET_IPV6;
 251                 subnet->net.ipv6.prefixlength = l;
 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, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
 261                 subnet->type = SUBNET_IPV4;
 262                 subnet->net.ipv4.prefixlength = 32;
 263                 subnet->weight = weight;
 264
 265                 for(i = 0; i < 4; i++) {
 266                         if(x[i] > 255)
 267                                 return false;
 268                         subnet->net.ipv4.address.x[i] = x[i];
 269                 }
 270
 271                 return true;
 272         }
 273
 274         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
 275                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
 276                 subnet->type = SUBNET_IPV6;
 277                 subnet->net.ipv6.prefixlength = 128;
 278                 subnet->weight = weight;
 279
 280                 for(i = 0; i < 8; i++)
 281                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 282
 283                 return true;
 284         }
 285
 286         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 287                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
 288                 subnet->type = SUBNET_MAC;
 289                 subnet->weight = weight;
 290
 291                 for(i = 0; i < 6; i++)
 292                         subnet->net.mac.address.x[i] = x[i];
 293
 294                 return true;
 295         }
 296
 297         return false;
 298 }
 299
 300 bool net2str(char *netstr, int len, const subnet_t *subnet)
 301 {
 302         cp();
 303
 304         if(!netstr || !subnet) {
 305                 logger(LOG_ERR, _("net2str() was called with netstr=%p, subnet=%p!\n"), netstr, subnet);
 306                 return false;
 307         }
 308
 309         switch (subnet->type) {
 310                 case SUBNET_MAC:
 311                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 312                                          subnet->net.mac.address.x[0],
 313                                          subnet->net.mac.address.x[1],
 314                                          subnet->net.mac.address.x[2],
 315                                          subnet->net.mac.address.x[3],
 316                                          subnet->net.mac.address.x[4],
 317                                          subnet->net.mac.address.x[5],
 318                                          subnet->weight);
 319                         break;
 320
 321                 case SUBNET_IPV4:
 322                         snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
 323                                          subnet->net.ipv4.address.x[0],
 324                                          subnet->net.ipv4.address.x[1],
 325                                          subnet->net.ipv4.address.x[2],
 326                                          subnet->net.ipv4.address.x[3],
 327                                          subnet->net.ipv4.prefixlength,
 328                                          subnet->weight);
 329                         break;
 330
 331                 case SUBNET_IPV6:
 332                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 333                                          ntohs(subnet->net.ipv6.address.x[0]),
 334                                          ntohs(subnet->net.ipv6.address.x[1]),
 335                                          ntohs(subnet->net.ipv6.address.x[2]),
 336                                          ntohs(subnet->net.ipv6.address.x[3]),
 337                                          ntohs(subnet->net.ipv6.address.x[4]),
 338                                          ntohs(subnet->net.ipv6.address.x[5]),
 339                                          ntohs(subnet->net.ipv6.address.x[6]),
 340                                          ntohs(subnet->net.ipv6.address.x[7]),
 341                                          subnet->net.ipv6.prefixlength,
 342                                          subnet->weight);
 343                         break;
 344
 345                 default:
 346                         logger(LOG_ERR,
 347                                    _("net2str() was called with unknown subnet type %d, exiting!"),
 348                                    subnet->type);
 349                         cp_trace();
 350                         exit(0);
 351         }
 352
 353         return true;
 354 }
 355
 356 /* Subnet lookup routines */
 357
 358 subnet_t *lookup_subnet(const node_t *owner, const subnet_t *subnet)
 359 {
 360         cp();
 361
 362         return avl_search(owner->subnet_tree, subnet);
 363 }
 364
 365 subnet_t *lookup_subnet_mac(const mac_t *address)
 366 {
 367         subnet_t *p, subnet = {0};
 368
 369         cp();
 370
 371         subnet.type = SUBNET_MAC;
 372         subnet.net.mac.address = *address;
 373         subnet.owner = NULL;
 374
 375         p = avl_search(subnet_tree, &subnet);
 376
 377         return p;
 378 }
 379
 380 subnet_t *lookup_subnet_ipv4(const ipv4_t *address)
 381 {
 382         subnet_t *p, *r = NULL, subnet = {0};
 383         avl_node_t *n;
 384         int i;
 385
 386         cp();
 387
 388         // Check if this address is cached
 389
 390         for(i = 0; i < 2; i++) {
 391                 if(!cache_ipv4_valid[i])
 392                         continue;
 393                 if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
 394                         return cache_ipv4_subnet[i];
 395         }
 396
 397         // Search all subnets for a matching one
 398
 399         subnet.type = SUBNET_IPV4;
 400         subnet.net.ipv4.address = *address;
 401         subnet.net.ipv4.prefixlength = 32;
 402         subnet.owner = NULL;
 403
 404         for(n = subnet_tree->head; n; n = n->next) {
 405                 p = n->data;
 406
 407                 if(!p || p->type != subnet.type)
 408                         continue;
 409
 410                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 411                         r = p;
 412                         if(p->owner->status.reachable)
 413                                 break;
 414                 }
 415         }
 416
 417         // Cache the result
 418
 419         cache_ipv4_slot = !cache_ipv4_slot;
 420         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
 421         cache_ipv4_subnet[cache_ipv4_slot] = r;
 422         cache_ipv4_valid[cache_ipv4_slot] = true;
 423
 424         return r;
 425 }
 426
 427 subnet_t *lookup_subnet_ipv6(const ipv6_t *address)
 428 {
 429         subnet_t *p, *r = NULL, subnet = {0};
 430         avl_node_t *n;
 431         int i;
 432
 433         cp();
 434
 435         // Check if this address is cached
 436
 437         for(i = 0; i < 2; i++) {
 438                 if(!cache_ipv6_valid[i])
 439                         continue;
 440                 if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
 441                         return cache_ipv6_subnet[i];
 442         }
 443
 444         // Search all subnets for a matching one
 445
 446         subnet.type = SUBNET_IPV6;
 447         subnet.net.ipv6.address = *address;
 448         subnet.net.ipv6.prefixlength = 128;
 449         subnet.owner = NULL;
 450
 451         for(n = subnet_tree->head; n; n = n->next) {
 452                 p = n->data;
 453
 454                 if(!p || p->type != subnet.type)
 455                         continue;
 456
 457                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 458                         r = p;
 459                         if(p->owner->status.reachable)
 460                                 break;
 461                 }
 462         }
 463
 464         // Cache the result
 465
 466         cache_ipv6_slot = !cache_ipv6_slot;
 467         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
 468         cache_ipv6_subnet[cache_ipv6_slot] = r;
 469         cache_ipv6_valid[cache_ipv6_slot] = true;
 470
 471         return r;
 472 }
 473
 474 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 475         avl_node_t *node;
 476         int i;
 477         char *envp[9] = {0};
 478         char netstr[MAXNETSTR];
 479         char *name, *address, *port;
 480         char empty[] = "";
 481
 482         // Prepare environment variables to be passed to the script
 483
 484         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 485         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 486         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 487         xasprintf(&envp[3], "NODE=%s", owner->name);
 488
 489         if(owner != myself) {
 490                 sockaddr2str(&owner->address, &address, &port);
 491                 // 4 and 5 are reserved for SUBNET and WEIGHT
 492                 xasprintf(&envp[6], "REMOTEADDRESS=%s", address);
 493                 xasprintf(&envp[7], "REMOTEPORT=%s", port);
 494         }
 495
 496         name = up ? "subnet-up" : "subnet-down";
 497
 498         if(!subnet) {
 499                 for(node = owner->subnet_tree->head; node; node = node->next) {
 500                         subnet = node->data;
 501                         if(!net2str(netstr, sizeof netstr, subnet))
 502                                 continue;
 503                         // Strip the weight from the subnet, and put it in its own environment variable
 504                         char *weight = strchr(netstr + 7, '#');
 505                         if(weight)
 506                                 *weight++ = 0;
 507                         else
 508                                 weight = empty;
 509
 510                         // Prepare the SUBNET and WEIGHT variables
 511                         if(envp[4])
 512                                 free(envp[4]);
 513                         if(envp[5])
 514                                 free(envp[5]);
 515                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 516                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 517
 518                         execute_script(name, envp);
 519                 }
 520         } else {
 521                 if(net2str(netstr + 7, sizeof netstr - 7, subnet)) {
 522                         // Strip the weight from the subnet, and put it in its own environment variable
 523                         char *weight = strchr(netstr + 7, '#');
 524                         if(weight)
 525                                 *weight++ = 0;
 526                         else
 527                                 weight = empty;
 528
 529                         // Prepare the SUBNET and WEIGHT variables
 530                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 531                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 532
 533                         execute_script(name, envp);
 534                 }
 535         }
 536
 537         for(i = 0; envp[i] && i < 9; i++)
 538                 free(envp[i]);
 539 }
 540
 541 void dump_subnets(void)
 542 {
 543         char netstr[MAXNETSTR];
 544         subnet_t *subnet;
 545         avl_node_t *node;
 546
 547         cp();
 548
 549         logger(LOG_DEBUG, _("Subnet list:"));
 550
 551         for(node = subnet_tree->head; node; node = node->next) {
 552                 subnet = node->data;
 553                 if(!net2str(netstr, sizeof netstr, subnet))
 554                         continue;
 555                 logger(LOG_DEBUG, _(" %s owner %s"), netstr, subnet->owner->name);
 556         }
 557
 558         logger(LOG_DEBUG, _("End of subnet list."));
 559 }