git.meshlink.io Git - meshlink/blob - src/subnet.c

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000-2010 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 "splay_tree.h"
  24 #include "control_common.h"
  25 #include "device.h"
  26 #include "logger.h"
  27 #include "net.h"
  28 #include "netutl.h"
  29 #include "node.h"
  30 #include "process.h"
  31 #include "subnet.h"
  32 #include "utils.h"
  33 #include "xalloc.h"
  34
  35 /* lists type of subnet */
  36
  37 splay_tree_t *subnet_tree;
  38
  39 /* Subnet lookup cache */
  40
  41 static ipv4_t cache_ipv4_address[2];
  42 static subnet_t *cache_ipv4_subnet[2];
  43 static bool cache_ipv4_valid[2];
  44 static int cache_ipv4_slot;
  45
  46 static ipv6_t cache_ipv6_address[2];
  47 static subnet_t *cache_ipv6_subnet[2];
  48 static bool cache_ipv6_valid[2];
  49 static int cache_ipv6_slot;
  50
  51 static mac_t cache_mac_address[2];
  52 static subnet_t *cache_mac_subnet[2];
  53 static bool cache_mac_valid[2];
  54 static int cache_mac_slot;
  55
  56 void subnet_cache_flush(void) {
  57         cache_ipv4_valid[0] = cache_ipv4_valid[1] = false;
  58         cache_ipv6_valid[0] = cache_ipv6_valid[1] = false;
  59         cache_mac_valid[0] = cache_mac_valid[1] = false;
  60 }
  61
  62 /* Subnet comparison */
  63
  64 static int subnet_compare_mac(const subnet_t *a, const subnet_t *b) {
  65         int result;
  66
  67         result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof a->net.mac.address);
  68
  69         if(result)
  70                 return result;
  71
  72         result = a->weight - b->weight;
  73
  74         if(result || !a->owner || !b->owner)
  75                 return result;
  76
  77         return strcmp(a->owner->name, b->owner->name);
  78 }
  79
  80 static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b) {
  81         int result;
  82
  83         result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
  84
  85         if(result)
  86                 return result;
  87
  88         result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
  89
  90         if(result)
  91                 return result;
  92
  93         result = a->weight - b->weight;
  94
  95         if(result || !a->owner || !b->owner)
  96                 return result;
  97
  98         return strcmp(a->owner->name, b->owner->name);
  99 }
 100
 101 static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b) {
 102         int result;
 103
 104         result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
 105
 106         if(result)
 107                 return result;
 108
 109         result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
 110
 111         if(result)
 112                 return result;
 113
 114         result = a->weight - b->weight;
 115
 116         if(result || !a->owner || !b->owner)
 117                 return result;
 118
 119         return strcmp(a->owner->name, b->owner->name);
 120 }
 121
 122 int subnet_compare(const subnet_t *a, const subnet_t *b) {
 123         int result;
 124
 125         result = a->type - b->type;
 126
 127         if(result)
 128                 return result;
 129
 130         switch (a->type) {
 131         case SUBNET_MAC:
 132                 return subnet_compare_mac(a, b);
 133         case SUBNET_IPV4:
 134                 return subnet_compare_ipv4(a, b);
 135         case SUBNET_IPV6:
 136                 return subnet_compare_ipv6(a, b);
 137         default:
 138                 logger(LOG_ERR, "subnet_compare() was called with unknown subnet type %d, exitting!",
 139                            a->type);
 140                 exit(0);
 141         }
 142
 143         return 0;
 144 }
 145
 146 /* Initialising trees */
 147
 148 void init_subnets(void) {
 149         subnet_tree = splay_alloc_tree((splay_compare_t) subnet_compare, (splay_action_t) free_subnet);
 150
 151         subnet_cache_flush();
 152 }
 153
 154 void exit_subnets(void) {
 155         splay_delete_tree(subnet_tree);
 156 }
 157
 158 splay_tree_t *new_subnet_tree(void) {
 159         return splay_alloc_tree((splay_compare_t) subnet_compare, NULL);
 160 }
 161
 162 void free_subnet_tree(splay_tree_t *subnet_tree) {
 163         splay_delete_tree(subnet_tree);
 164 }
 165
 166 /* Allocating and freeing space for subnets */
 167
 168 subnet_t *new_subnet(void) {
 169         return xmalloc_and_zero(sizeof(subnet_t));
 170 }
 171
 172 void free_subnet(subnet_t *subnet) {
 173         free(subnet);
 174 }
 175
 176 /* Adding and removing subnets */
 177
 178 void subnet_add(node_t *n, subnet_t *subnet) {
 179         subnet->owner = n;
 180
 181         splay_insert(subnet_tree, subnet);
 182         splay_insert(n->subnet_tree, subnet);
 183
 184         subnet_cache_flush();
 185 }
 186
 187 void subnet_del(node_t *n, subnet_t *subnet) {
 188         splay_delete(n->subnet_tree, subnet);
 189         splay_delete(subnet_tree, subnet);
 190
 191         subnet_cache_flush();
 192 }
 193
 194 /* Ascii representation of subnets */
 195
 196 bool str2net(subnet_t *subnet, const char *subnetstr) {
 197         int i, l;
 198         uint16_t x[8];
 199         int weight = 10;
 200
 201         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
 202                           &x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
 203                 if(l < 0 || l > 32)
 204                         return false;
 205
 206                 subnet->type = SUBNET_IPV4;
 207                 subnet->net.ipv4.prefixlength = l;
 208                 subnet->weight = weight;
 209
 210                 for(i = 0; i < 4; i++) {
 211                         if(x[i] > 255)
 212                                 return false;
 213                         subnet->net.ipv4.address.x[i] = x[i];
 214                 }
 215
 216                 return true;
 217         }
 218
 219         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 220                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
 221                           &l, &weight) >= 9) {
 222                 if(l < 0 || l > 128)
 223                         return false;
 224
 225                 subnet->type = SUBNET_IPV6;
 226                 subnet->net.ipv6.prefixlength = l;
 227                 subnet->weight = weight;
 228
 229                 for(i = 0; i < 8; i++)
 230                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 231
 232                 return true;
 233         }
 234
 235         if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
 236                 subnet->type = SUBNET_IPV4;
 237                 subnet->net.ipv4.prefixlength = 32;
 238                 subnet->weight = weight;
 239
 240                 for(i = 0; i < 4; i++) {
 241                         if(x[i] > 255)
 242                                 return false;
 243                         subnet->net.ipv4.address.x[i] = x[i];
 244                 }
 245
 246                 return true;
 247         }
 248
 249         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
 250                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
 251                 subnet->type = SUBNET_IPV6;
 252                 subnet->net.ipv6.prefixlength = 128;
 253                 subnet->weight = weight;
 254
 255                 for(i = 0; i < 8; i++)
 256                         subnet->net.ipv6.address.x[i] = htons(x[i]);
 257
 258                 return true;
 259         }
 260
 261         if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 262                           &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
 263                 subnet->type = SUBNET_MAC;
 264                 subnet->weight = weight;
 265
 266                 for(i = 0; i < 6; i++)
 267                         subnet->net.mac.address.x[i] = x[i];
 268
 269                 return true;
 270         }
 271
 272         return false;
 273 }
 274
 275 bool net2str(char *netstr, int len, const subnet_t *subnet) {
 276         if(!netstr || !subnet) {
 277                 logger(LOG_ERR, "net2str() was called with netstr=%p, subnet=%p!", netstr, subnet);
 278                 return false;
 279         }
 280
 281         switch (subnet->type) {
 282                 case SUBNET_MAC:
 283                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
 284                                          subnet->net.mac.address.x[0],
 285                                          subnet->net.mac.address.x[1],
 286                                          subnet->net.mac.address.x[2],
 287                                          subnet->net.mac.address.x[3],
 288                                          subnet->net.mac.address.x[4],
 289                                          subnet->net.mac.address.x[5],
 290                                          subnet->weight);
 291                         break;
 292
 293                 case SUBNET_IPV4:
 294                         snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
 295                                          subnet->net.ipv4.address.x[0],
 296                                          subnet->net.ipv4.address.x[1],
 297                                          subnet->net.ipv4.address.x[2],
 298                                          subnet->net.ipv4.address.x[3],
 299                                          subnet->net.ipv4.prefixlength,
 300                                          subnet->weight);
 301                         break;
 302
 303                 case SUBNET_IPV6:
 304                         snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
 305                                          ntohs(subnet->net.ipv6.address.x[0]),
 306                                          ntohs(subnet->net.ipv6.address.x[1]),
 307                                          ntohs(subnet->net.ipv6.address.x[2]),
 308                                          ntohs(subnet->net.ipv6.address.x[3]),
 309                                          ntohs(subnet->net.ipv6.address.x[4]),
 310                                          ntohs(subnet->net.ipv6.address.x[5]),
 311                                          ntohs(subnet->net.ipv6.address.x[6]),
 312                                          ntohs(subnet->net.ipv6.address.x[7]),
 313                                          subnet->net.ipv6.prefixlength,
 314                                          subnet->weight);
 315                         break;
 316
 317                 default:
 318                         logger(LOG_ERR,
 319                                    "net2str() was called with unknown subnet type %d, exiting!",
 320                                    subnet->type);
 321                         exit(0);
 322         }
 323
 324         return true;
 325 }
 326
 327 /* Subnet lookup routines */
 328
 329 subnet_t *lookup_subnet(const node_t *owner, const subnet_t *subnet) {
 330         return splay_search(owner->subnet_tree, subnet);
 331 }
 332
 333 subnet_t *lookup_subnet_mac(const node_t *owner, const mac_t *address) {
 334         subnet_t *p, *r = NULL;
 335         splay_node_t *n;
 336         int i;
 337
 338         // Check if this address is cached
 339
 340         for(i = 0; i < 2; i++) {
 341                 if(!cache_mac_valid[i])
 342                         continue;
 343                 if(owner && cache_mac_subnet[i] && cache_mac_subnet[i]->owner != owner)
 344                         continue;
 345                 if(!memcmp(address, &cache_mac_address[i], sizeof *address))
 346                         return cache_mac_subnet[i];
 347         }
 348
 349         // Search all subnets for a matching one
 350
 351         for(n = owner ? owner->subnet_tree->head : subnet_tree->head; n; n = n->next) {
 352                 p = n->data;
 353
 354                 if(!p || p->type != SUBNET_MAC)
 355                         continue;
 356
 357                 if(!memcmp(address, &p->net.mac.address, sizeof *address)) {
 358                         r = p;
 359                         if(p->owner->status.reachable)
 360                                 break;
 361                 }
 362         }
 363
 364         // Cache the result
 365
 366         cache_mac_slot = !cache_mac_slot;
 367         memcpy(&cache_mac_address[cache_mac_slot], address, sizeof *address);
 368         cache_mac_subnet[cache_mac_slot] = r;
 369         cache_mac_valid[cache_mac_slot] = true;
 370
 371         return r;
 372 }
 373
 374 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
 375         subnet_t *p, *r = NULL;
 376         splay_node_t *n;
 377         int i;
 378
 379         // Check if this address is cached
 380
 381         for(i = 0; i < 2; i++) {
 382                 if(!cache_ipv4_valid[i])
 383                         continue;
 384                 if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
 385                         return cache_ipv4_subnet[i];
 386         }
 387
 388         // Search all subnets for a matching one
 389
 390         for(n = subnet_tree->head; n; n = n->next) {
 391                 p = n->data;
 392
 393                 if(!p || p->type != SUBNET_IPV4)
 394                         continue;
 395
 396                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 397                         r = p;
 398                         if(p->owner->status.reachable)
 399                                 break;
 400                 }
 401         }
 402
 403         // Cache the result
 404
 405         cache_ipv4_slot = !cache_ipv4_slot;
 406         memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
 407         cache_ipv4_subnet[cache_ipv4_slot] = r;
 408         cache_ipv4_valid[cache_ipv4_slot] = true;
 409
 410         return r;
 411 }
 412
 413 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 414         subnet_t *p, *r = NULL;
 415         splay_node_t *n;
 416         int i;
 417
 418         // Check if this address is cached
 419
 420         for(i = 0; i < 2; i++) {
 421                 if(!cache_ipv6_valid[i])
 422                         continue;
 423                 if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
 424                         return cache_ipv6_subnet[i];
 425         }
 426
 427         // Search all subnets for a matching one
 428
 429         for(n = subnet_tree->head; n; n = n->next) {
 430                 p = n->data;
 431
 432                 if(!p || p->type != SUBNET_IPV6)
 433                         continue;
 434
 435                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 436                         r = p;
 437                         if(p->owner->status.reachable)
 438                                 break;
 439                 }
 440         }
 441
 442         // Cache the result
 443
 444         cache_ipv6_slot = !cache_ipv6_slot;
 445         memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
 446         cache_ipv6_subnet[cache_ipv6_slot] = r;
 447         cache_ipv6_valid[cache_ipv6_slot] = true;
 448
 449         return r;
 450 }
 451
 452 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 453         splay_node_t *node;
 454         int i;
 455         char *envp[9] = {NULL};
 456         char netstr[MAXNETSTR];
 457         char *name, *address, *port;
 458         char empty[] = "";
 459
 460         // Prepare environment variables to be passed to the script
 461
 462         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 463         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 464         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 465         xasprintf(&envp[3], "NODE=%s", owner->name);
 466
 467         if(owner != myself) {
 468                 sockaddr2str(&owner->address, &address, &port);
 469                 // 4 and 5 are reserved for SUBNET and WEIGHT
 470                 xasprintf(&envp[6], "REMOTEADDRESS=%s", address);
 471                 xasprintf(&envp[7], "REMOTEPORT=%s", port);
 472         }
 473
 474         name = up ? "subnet-up" : "subnet-down";
 475
 476         if(!subnet) {
 477                 for(node = owner->subnet_tree->head; node; node = node->next) {
 478                         subnet = node->data;
 479                         if(!net2str(netstr, sizeof netstr, subnet))
 480                                 continue;
 481                         // Strip the weight from the subnet, and put it in its own environment variable
 482                         char *weight = strchr(netstr, '#');
 483                         if(weight)
 484                                 *weight++ = 0;
 485                         else
 486                                 weight = empty;
 487
 488                         // Prepare the SUBNET and WEIGHT variables
 489                         if(envp[4])
 490                                 free(envp[4]);
 491                         if(envp[5])
 492                                 free(envp[5]);
 493                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 494                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 495
 496                         execute_script(name, envp);
 497                 }
 498         } else {
 499                 if(net2str(netstr, sizeof netstr, subnet)) {
 500                         // Strip the weight from the subnet, and put it in its own environment variable
 501                         char *weight = strchr(netstr, '#');
 502                         if(weight)
 503                                 *weight++ = 0;
 504                         else
 505                                 weight = empty;
 506
 507                         // Prepare the SUBNET and WEIGHT variables
 508                         xasprintf(&envp[4], "SUBNET=%s", netstr);
 509                         xasprintf(&envp[5], "WEIGHT=%s", weight);
 510
 511                         execute_script(name, envp);
 512                 }
 513         }
 514
 515         for(i = 0; envp[i] && i < 8; i++)
 516                 free(envp[i]);
 517 }
 518
 519 bool dump_subnets(connection_t *c) {
 520         char netstr[MAXNETSTR];
 521         subnet_t *subnet;
 522         splay_node_t *node;
 523
 524         for(node = subnet_tree->head; node; node = node->next) {
 525                 subnet = node->data;
 526                 if(!net2str(netstr, sizeof netstr, subnet))
 527                         continue;
 528                 send_request(c, "%d %d %s owner %s",
 529                                 CONTROL, REQ_DUMP_SUBNETS,
 530                                 netstr, subnet->owner->name);
 531         }
 532
 533         return send_request(c, "%d %d", CONTROL, REQ_DUMP_SUBNETS);
 534 }