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         int result;
  59
  60         result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
  61
  62         if(result)
  63                 return result;
  64
  65         result = a->weight - b->weight;
  66
  67         if(result || !a->owner || !b->owner)
  68                 return result;
  69
  70         return strcmp(a->owner->name, b->owner->name);
  71 }
  72
  73 static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b) {
  74         int result;
  75
  76         result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
  77
  78         if(result)
  79                 return result;
  80
  81         result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
  82
  83         if(result)
  84                 return result;
  85
  86         result = a->weight - b->weight;
  87
  88         if(result || !a->owner || !b->owner)
  89                 return result;
  90
  91         return strcmp(a->owner->name, b->owner->name);
  92 }
  93
  94 static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b) {
  95         int result;
  96
  97         result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
  98
  99         if(result)
 100                 return result;
 101
 102         result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
 103
 104         if(result)
 105                 return result;
 106
 107         result = a->weight - b->weight;
 108
 109         if(result || !a->owner || !b->owner)
 110                 return result;
 111
 112         return strcmp(a->owner->name, b->owner->name);
 113 }
 114
 115 int subnet_compare(const subnet_t *a, const subnet_t *b) {
 116         int result;
 117
 118         result = a->type - b->type;
 119
 120         if(result)
 121                 return result;
 122
 123         switch (a->type) {
 124         case SUBNET_MAC:
 125                 return subnet_compare_mac(a, b);
 126         case SUBNET_IPV4:
 127                 return subnet_compare_ipv4(a, b);
 128         case SUBNET_IPV6:
 129                 return subnet_compare_ipv6(a, b);
 130         default:
 131                 logger(LOG_ERR, "subnet_compare() was called with unknown subnet type %d, exitting!",
 132                            a->type);
 133                 exit(0);
 134         }
 135
 136         return 0;
 137 }
 138
 139 /* Initialising trees */
 140
 141 void init_subnets(void) {
 142         subnet_tree = avl_alloc_tree((avl_compare_t) subnet_compare, (avl_action_t) free_subnet);
 143
 144         subnet_cache_flush();
 145 }
 146
 147 void exit_subnets(void) {
 148         avl_delete_tree(subnet_tree);
 149 }
 150
 151 avl_tree_t *new_subnet_tree(void) {
 152         return avl_alloc_tree((avl_compare_t) subnet_compare, NULL);
 153 }
 154
 155 void free_subnet_tree(avl_tree_t *subnet_tree) {
 156         avl_delete_tree(subnet_tree);
 157 }
 158
 159 /* Allocating and freeing space for subnets */
 160
 161 subnet_t *new_subnet(void) {
 162         return xmalloc_and_zero(sizeof(subnet_t));
 163 }
 164
 165 void free_subnet(subnet_t *subnet) {
 166         free(subnet);
 167 }
 168
 169 /* Adding and removing subnets */
 170
 171 void subnet_add(node_t *n, subnet_t *subnet) {
 172         subnet->owner = n;
 173
 174         avl_insert(subnet_tree, subnet);
 175         avl_insert(n->subnet_tree, subnet);
 176
 177         subnet_cache_flush();
 178 }
 179
 180 void subnet_del(node_t *n, subnet_t *subnet) {
 181         avl_delete(n->subnet_tree, subnet);
 182         avl_delete(subnet_tree, subnet);
 183
 184         subnet_cache_flush();
 185 }
 186
 187 /* Ascii representation of subnets */
 188
 189 bool str2net(subnet_t *subnet, const char *subnetstr) {
 190         int i, l;
 191         uint16_t x[8];
 192         int weight = 10;
 193
 194         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
 195                           &x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
 196                 if(l < 0 || l > 32)
 197                         return false;
 198
 199                 subnet->type = SUBNET_IPV4;
 200                 subnet->net.ipv4.prefixlength = l;
 201                 subnet->weight = weight;
 202
 203                 for(i = 0; i < 4; i++) {
 204                         if(x[i] > 255)
 205                                 return false;
 206                         subnet->net.ipv4.address.x[i] = x[i];
 207                 }
 208
 209                 return true;
 210         }
 211
 212         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 213                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
 214                           &l, &weight) >= 9) {
 215                 if(l < 0 || l > 128)
 216                         return false;
 217
 218                 subnet->type = SUBNET_IPV6;
 219                 subnet->net.ipv6.prefixlength = l;
 220                 subnet->weight = weight;
 221
 222                 for(i = 0; i < 8; i++)
 223                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 224
 225                 return true;
 226         }
 227
 228         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
 229                 subnet->type = SUBNET_IPV4;
 230                 subnet->net.ipv4.prefixlength = 32;
 231                 subnet->weight = weight;
 232
 233                 for(i = 0; i < 4; i++) {
 234                         if(x[i] > 255)
 235                                 return false;
 236                         subnet->net.ipv4.address.x[i] = x[i];
 237                 }
 238
 239                 return true;
 240         }
 241
 242         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
 243                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
 244                 subnet->type = SUBNET_IPV6;
 245                 subnet->net.ipv6.prefixlength = 128;
 246                 subnet->weight = weight;
 247
 248                 for(i = 0; i < 8; i++)
 249                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 250
 251                 return true;
 252         }
 253
 254         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 255                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
 256                 subnet->type = SUBNET_MAC;
 257                 subnet->weight = weight;
 258
 259                 for(i = 0; i < 6; i++)
 260                         subnet->net.mac.address.x[i] = x[i];
 261
 262                 return true;
 263         }
 264
 265         return false;
 266 }
 267
 268 bool net2str(char *netstr, int len, const subnet_t *subnet) {
 269         if(!netstr || !subnet) {
 270                 logger(LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!\n", netstr, subnet);
 271                 return false;
 272         }
 273
 274         switch (subnet->type) {
 275                 case SUBNET_MAC:
 276                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 277                                          subnet->net.mac.address.x[0],
 278                                          subnet->net.mac.address.x[1],
 279                                          subnet->net.mac.address.x[2],
 280                                          subnet->net.mac.address.x[3],
 281                                          subnet->net.mac.address.x[4],
 282                                          subnet->net.mac.address.x[5],
 283                                          subnet->weight);
 284                         break;
 285
 286                 case SUBNET_IPV4:
 287                         snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
 288                                          subnet->net.ipv4.address.x[0],
 289                                          subnet->net.ipv4.address.x[1],
 290                                          subnet->net.ipv4.address.x[2],
 291                                          subnet->net.ipv4.address.x[3],
 292                                          subnet->net.ipv4.prefixlength,
 293                                          subnet->weight);
 294                         break;
 295
 296                 case SUBNET_IPV6:
 297                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 298                                          ntohs(subnet->net.ipv6.address.x[0]),
 299                                          ntohs(subnet->net.ipv6.address.x[1]),
 300                                          ntohs(subnet->net.ipv6.address.x[2]),
 301                                          ntohs(subnet->net.ipv6.address.x[3]),
 302                                          ntohs(subnet->net.ipv6.address.x[4]),
 303                                          ntohs(subnet->net.ipv6.address.x[5]),
 304                                          ntohs(subnet->net.ipv6.address.x[6]),
 305                                          ntohs(subnet->net.ipv6.address.x[7]),
 306                                          subnet->net.ipv6.prefixlength,
 307                                          subnet->weight);
 308                         break;
 309
 310                 default:
 311                         logger(LOG_ERR,
 312                                    "net2str() was called with unknown subnet type %d, exiting!",
 313                                    subnet->type);
 314                         exit(0);
 315         }
 316
 317         return true;
 318 }
 319
 320 /* Subnet lookup routines */
 321
 322 subnet_t *lookup_subnet(const node_t *owner, const subnet_t *subnet) {
 323         return avl_search(owner->subnet_tree, subnet);
 324 }
 325
 326 subnet_t *lookup_subnet_mac(const mac_t *address) {
 327         subnet_t *p, subnet = {0};
 328
 329         subnet.type = SUBNET_MAC;
 330         subnet.net.mac.address = *address;
 331         subnet.owner = NULL;
 332
 333         p = avl_search(subnet_tree, &subnet);
 334
 335         return p;
 336 }
 337
 338 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
 339         subnet_t *p, *r = NULL, subnet = {0};
 340         avl_node_t *n;
 341         int i;
 342
 343         // Check if this address is cached
 344
 345         for(i = 0; i < 2; i++) {
 346                 if(!cache_ipv4_valid[i])
 347                         continue;
 348                 if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
 349                         return cache_ipv4_subnet[i];
 350         }
 351
 352         // Search all subnets for a matching one
 353
 354         subnet.type = SUBNET_IPV4;
 355         subnet.net.ipv4.address = *address;
 356         subnet.net.ipv4.prefixlength = 32;
 357         subnet.owner = NULL;
 358
 359         for(n = subnet_tree->head; n; n = n->next) {
 360                 p = n->data;
 361
 362                 if(!p || p->type != subnet.type)
 363                         continue;
 364
 365                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 366                         r = p;
 367                         if(p->owner->status.reachable)
 368                                 break;
 369                 }
 370         }
 371
 372         // Cache the result
 373
 374         cache_ipv4_slot = !cache_ipv4_slot;
 375         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
 376         cache_ipv4_subnet[cache_ipv4_slot] = r;
 377         cache_ipv4_valid[cache_ipv4_slot] = true;
 378
 379         return r;
 380 }
 381
 382 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 383         subnet_t *p, *r = NULL, subnet = {0};
 384         avl_node_t *n;
 385         int i;
 386
 387         // Check if this address is cached
 388
 389         for(i = 0; i < 2; i++) {
 390                 if(!cache_ipv6_valid[i])
 391                         continue;
 392                 if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
 393                         return cache_ipv6_subnet[i];
 394         }
 395
 396         // Search all subnets for a matching one
 397
 398         subnet.type = SUBNET_IPV6;
 399         subnet.net.ipv6.address = *address;
 400         subnet.net.ipv6.prefixlength = 128;
 401         subnet.owner = NULL;
 402
 403         for(n = subnet_tree->head; n; n = n->next) {
 404                 p = n->data;
 405
 406                 if(!p || p->type != subnet.type)
 407                         continue;
 408
 409                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 410                         r = p;
 411                         if(p->owner->status.reachable)
 412                                 break;
 413                 }
 414         }
 415
 416         // Cache the result
 417
 418         cache_ipv6_slot = !cache_ipv6_slot;
 419         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
 420         cache_ipv6_subnet[cache_ipv6_slot] = r;
 421         cache_ipv6_valid[cache_ipv6_slot] = true;
 422
 423         return r;
 424 }
 425
 426 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 427         avl_node_t *node;
 428         int i;
 429         char *envp[9] = {0};
 430         char netstr[MAXNETSTR];
 431         char *name, *address, *port;
 432         char empty[] = "";
 433
 434         // Prepare environment variables to be passed to the script
 435
 436         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 437         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 438         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 439         xasprintf(&envp[3], "NODE=%s", owner->name);
 440
 441         if(owner != myself) {
 442                 sockaddr2str(&owner->address, &address, &port);
 443                 // 4 and 5 are reserved for SUBNET and WEIGHT
 444                 xasprintf(&envp[6], "REMOTEADDRESS=%s", address);
 445                 xasprintf(&envp[7], "REMOTEPORT=%s", port);
 446         }
 447
 448         name = up ? "subnet-up" : "subnet-down";
 449
 450         if(!subnet) {
 451                 for(node = owner->subnet_tree->head; node; node = node->next) {
 452                         subnet = node->data;
 453                         if(!net2str(netstr, sizeof netstr, subnet))
 454                                 continue;
 455                         // Strip the weight from the subnet, and put it in its own environment variable
 456                         char *weight = strchr(netstr + 7, '#');
 457                         if(weight)
 458                                 *weight++ = 0;
 459                         else
 460                                 weight = empty;
 461
 462                         // Prepare the SUBNET and WEIGHT variables
 463                         if(envp[4])
 464                                 free(envp[4]);
 465                         if(envp[5])
 466                                 free(envp[5]);
 467                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 468                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 469
 470                         execute_script(name, envp);
 471                 }
 472         } else {
 473                 if(net2str(netstr + 7, sizeof netstr - 7, subnet)) {
 474                         // Strip the weight from the subnet, and put it in its own environment variable
 475                         char *weight = strchr(netstr + 7, '#');
 476                         if(weight)
 477                                 *weight++ = 0;
 478                         else
 479                                 weight = empty;
 480
 481                         // Prepare the SUBNET and WEIGHT variables
 482                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 483                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 484
 485                         execute_script(name, envp);
 486                 }
 487         }
 488
 489         for(i = 0; envp[i] && i < 9; i++)
 490                 free(envp[i]);
 491 }
 492
 493 void dump_subnets(void) {
 494         char netstr[MAXNETSTR];
 495         subnet_t *subnet;
 496         avl_node_t *node;
 497
 498         logger(LOG_DEBUG, "Subnet list:");
 499
 500         for(node = subnet_tree->head; node; node = node->next) {
 501                 subnet = node->data;
 502                 if(!net2str(netstr, sizeof netstr, subnet))
 503                         continue;
 504                 logger(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 505         }
 506
 507         logger(LOG_DEBUG, "End of subnet list.");
 508 }