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

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000-2017 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 "hash.h"
  26 #include "logger.h"
  27 #include "net.h"
  28 #include "netutl.h"
  29 #include "node.h"
  30 #include "script.h"
  31 #include "subnet.h"
  32 #include "xalloc.h"
  33
  34 /* lists type of subnet */
  35 uint32_t hash_seed;
  36 splay_tree_t subnet_tree = {
  37         .compare = (splay_compare_t) subnet_compare,
  38         .delete = (splay_action_t) free_subnet,
  39 };
  40
  41 /* Subnet lookup cache */
  42
  43 static uint32_t hash_function_ipv4_t(const ipv4_t *p) {
  44         /*
  45         This basic hash works because
  46         a) Most IPv4 networks routed via tinc are not /0
  47         b) Most IPv4 networks have more unique low order bits
  48         */
  49         uint16_t *halfwidth = (uint16_t *)p;
  50         uint32_t hash = hash_seed;
  51
  52 #if __BYTE_ORDER == __LITTLE_ENDIAN
  53         // 10.0.x.x/16 part
  54         hash += halfwidth[1] * 0x9e370001UL;
  55
  56         // x.x.0.[0-255] part
  57 #if SUBNET_HASH_SIZE >= 0x10000
  58         return hash ^ halfwidth[0];
  59 #else
  60         // ensure that we have a /24 with no collisions on 32bit
  61         return hash ^ ntohs(halfwidth[0]);
  62 #endif // _____LP64_____
  63 #else
  64         // 10.0.x.x/16 part
  65         hash += halfwidth[0] * 0x9e370001UL;
  66
  67         // x.x.0.[0-255] part (ntohs is nop on big endian)
  68         return hash ^ halfwidth[1];
  69 #endif // __BYTE_ORDER == __LITTLE_ENDIAN
  70 }
  71
  72
  73 static uint32_t hash_function_ipv6_t(const ipv6_t *p) {
  74         uint32_t *fullwidth = (uint32_t *)p;
  75         uint32_t hash = hash_seed;
  76
  77         for(int i = 0; i < 4; i++) {
  78                 hash += fullwidth[i];
  79                 hash *= 0x9e370001UL;
  80         }
  81
  82         return hash;
  83 }
  84
  85 static uint32_t hash_function_mac_t(const mac_t *p) {
  86         uint16_t *halfwidth = (uint16_t *)p;
  87         uint32_t hash = hash_seed;
  88
  89         for(int i = 0; i < 3; i++) {
  90                 hash += halfwidth[i];
  91                 hash *= 0x9e370001UL;
  92         }
  93
  94         return hash;
  95 }
  96
  97 hash_define(ipv4_t, SUBNET_HASH_SIZE)
  98 hash_define(ipv6_t, SUBNET_HASH_SIZE)
  99 hash_define(mac_t, SUBNET_HASH_SIZE)
 100
 101 hash_new(ipv4_t, ipv4_cache);
 102 hash_new(ipv6_t, ipv6_cache);
 103 hash_new(mac_t, mac_cache);
 104
 105
 106 void subnet_cache_flush_table(subnet_type_t stype) {
 107         // NOTE: a subnet type of SUBNET_TYPES can be used to clear all hash tables
 108
 109         if(stype != SUBNET_IPV6) { // ipv4
 110                 hash_clear(ipv4_t, &ipv4_cache);
 111         }
 112
 113         if(stype != SUBNET_IPV4) { // ipv6
 114                 hash_clear(ipv6_t, &ipv6_cache);
 115         }
 116
 117         hash_clear(mac_t, &mac_cache);
 118 }
 119
 120 /* Initialising trees */
 121
 122 void init_subnets(void) {
 123         hash_seed = (uint32_t)rand();
 124 }
 125
 126 void exit_subnets(void) {
 127         splay_empty_tree(&subnet_tree);
 128         subnet_cache_flush_tables();
 129 }
 130
 131 void init_subnet_tree(splay_tree_t *tree) {
 132         memset(tree, 0, sizeof(*tree));
 133         tree->compare = (splay_compare_t) subnet_compare;
 134 }
 135
 136 /* Allocating and freeing space for subnets */
 137
 138 subnet_t *new_subnet(void) {
 139         return xzalloc(sizeof(subnet_t));
 140 }
 141
 142 void free_subnet(subnet_t *subnet) {
 143         free(subnet);
 144 }
 145
 146 void subnet_cache_flush_tables(void) {
 147         // flushes all the tables
 148         hash_clear(ipv4_t, &ipv4_cache);
 149         hash_clear(ipv6_t, &ipv6_cache);
 150         hash_clear(mac_t, &mac_cache);
 151 }
 152
 153 void subnet_cache_flush(subnet_t *subnet) {
 154         switch(subnet->type) {
 155         case SUBNET_IPV4:
 156                 if(subnet->net.ipv4.prefixlength == 32) {
 157                         hash_delete(ipv4_t, &ipv4_cache, &subnet->net.ipv4.address);
 158                         return;
 159                 }
 160
 161                 break;
 162
 163         case SUBNET_IPV6:
 164                 if(subnet->net.ipv4.prefixlength == 128) {
 165                         hash_delete(ipv6_t, &ipv6_cache, &subnet->net.ipv6.address);
 166                         return;
 167                 }
 168
 169                 break;
 170
 171         case SUBNET_MAC:
 172                 hash_delete(mac_t, &mac_cache, &subnet->net.mac.address);
 173                 return;
 174         }
 175
 176         subnet_cache_flush_table(subnet->type);
 177 }
 178
 179 /* Adding and removing subnets */
 180
 181 void subnet_add(node_t *n, subnet_t *subnet) {
 182         subnet->owner = n;
 183
 184         splay_insert(&subnet_tree, subnet);
 185
 186         if(n) {
 187                 splay_insert(&n->subnet_tree, subnet);
 188         }
 189
 190         subnet_cache_flush(subnet);
 191 }
 192
 193 void subnet_del(node_t *n, subnet_t *subnet) {
 194         if(n) {
 195                 splay_delete(&n->subnet_tree, subnet);
 196         }
 197
 198         splay_delete(&subnet_tree, subnet);
 199
 200         subnet_cache_flush(subnet);
 201 }
 202
 203 /* Subnet lookup routines */
 204
 205 subnet_t *lookup_subnet(node_t *owner, const subnet_t *subnet) {
 206         return splay_search(&owner->subnet_tree, subnet);
 207 }
 208
 209 subnet_t *lookup_subnet_mac(const node_t *owner, const mac_t *address) {
 210         subnet_t *r = NULL;
 211
 212         // Check if this address is cached
 213
 214         if((r = hash_search(mac_t, &mac_cache, address))) {
 215                 return r;
 216         }
 217
 218         // Search all subnets for a matching one
 219
 220         for splay_each(subnet_t, p, owner ? &owner->subnet_tree : &subnet_tree) {
 221                 if(!p || p->type != SUBNET_MAC) {
 222                         continue;
 223                 }
 224
 225                 if(!memcmp(address, &p->net.mac.address, sizeof(*address))) {
 226                         r = p;
 227
 228                         if(!p->owner || p->owner->status.reachable) {
 229                                 break;
 230                         }
 231                 }
 232         }
 233
 234         // Cache the result
 235
 236         if(r) {
 237                 hash_insert(mac_t, &mac_cache, address, r);
 238         }
 239
 240         return r;
 241 }
 242
 243 subnet_t *lookup_subnet_ipv4(const ipv4_t *address) {
 244         subnet_t *r = NULL;
 245
 246         // Check if this address is cached
 247
 248         if((r = hash_search(ipv4_t, &ipv4_cache, address))) {
 249                 return r;
 250         }
 251
 252         // Search all subnets for a matching one
 253
 254         for splay_each(subnet_t, p, &subnet_tree) {
 255                 if(!p || p->type != SUBNET_IPV4) {
 256                         continue;
 257                 }
 258
 259                 if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
 260                         r = p;
 261
 262                         if(!p->owner || p->owner->status.reachable) {
 263                                 break;
 264                         }
 265                 }
 266         }
 267
 268         // Cache the result
 269
 270         if(r) {
 271                 hash_insert(ipv4_t, &ipv4_cache, address, r);
 272         }
 273
 274         return r;
 275 }
 276
 277 subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 278         subnet_t *r = NULL;
 279
 280         // Check if this address is cached
 281
 282         if((r = hash_search(ipv6_t, &ipv6_cache, address))) {
 283                 return r;
 284         }
 285
 286         // Search all subnets for a matching one
 287
 288         for splay_each(subnet_t, p, &subnet_tree) {
 289                 if(!p || p->type != SUBNET_IPV6) {
 290                         continue;
 291                 }
 292
 293                 if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
 294                         r = p;
 295
 296                         if(!p->owner || p->owner->status.reachable) {
 297                                 break;
 298                         }
 299                 }
 300         }
 301
 302         // Cache the result
 303
 304         if(r) {
 305                 hash_insert(ipv6_t, &ipv6_cache, address, r);
 306         }
 307
 308         return r;
 309 }
 310
 311 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
 312         char netstr[MAXNETSTR];
 313         char *name, *address, *port;
 314         char empty[] = "";
 315
 316         // Prepare environment variables to be passed to the script
 317
 318         environment_t env;
 319         environment_init(&env);
 320         environment_add(&env, "NODE=%s", owner->name);
 321
 322         if(owner != myself) {
 323                 sockaddr2str(&owner->address, &address, &port);
 324                 environment_add(&env, "REMOTEADDRESS=%s", address);
 325                 environment_add(&env, "REMOTEPORT=%s", port);
 326                 free(port);
 327                 free(address);
 328         }
 329
 330         int env_subnet = environment_add(&env, NULL);
 331         int env_weight = environment_add(&env, NULL);
 332
 333         name = up ? "subnet-up" : "subnet-down";
 334
 335         if(!subnet) {
 336                 for splay_each(subnet_t, subnet, &owner->subnet_tree) {
 337                         if(!net2str(netstr, sizeof(netstr), subnet)) {
 338                                 continue;
 339                         }
 340
 341                         // Strip the weight from the subnet, and put it in its own environment variable
 342                         char *weight = strchr(netstr, '#');
 343
 344                         if(weight) {
 345                                 *weight++ = 0;
 346                         } else {
 347                                 weight = empty;
 348                         }
 349
 350                         // Prepare the SUBNET and WEIGHT variables
 351                         environment_update(&env, env_subnet, "SUBNET=%s", netstr);
 352                         environment_update(&env, env_weight, "WEIGHT=%s", weight);
 353
 354                         execute_script(name, &env);
 355                 }
 356         } else {
 357                 if(net2str(netstr, sizeof(netstr), subnet)) {
 358                         // Strip the weight from the subnet, and put it in its own environment variable
 359                         char *weight = strchr(netstr, '#');
 360
 361                         if(weight) {
 362                                 *weight++ = 0;
 363                         } else {
 364                                 weight = empty;
 365                         }
 366
 367                         // Prepare the SUBNET and WEIGHT variables
 368                         environment_update(&env, env_subnet, "SUBNET=%s", netstr);
 369                         environment_update(&env, env_weight, "WEIGHT=%s", weight);
 370
 371                         execute_script(name, &env);
 372                 }
 373         }
 374
 375         environment_exit(&env);
 376 }
 377
 378 bool dump_subnets(connection_t *c) {
 379         for splay_each(subnet_t, subnet, &subnet_tree) {
 380                 char netstr[MAXNETSTR];
 381
 382                 if(!net2str(netstr, sizeof(netstr), subnet)) {
 383                         continue;
 384                 }
 385
 386                 send_request(c, "%d %d %s %s",
 387                              CONTROL, REQ_DUMP_SUBNETS,
 388                              netstr, subnet->owner ? subnet->owner->name : "(broadcast)");
 389         }
 390
 391         return send_request(c, "%d %d", CONTROL, REQ_DUMP_SUBNETS);
 392 }