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

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000-2002 Guus Sliepen <guus@sliepen.warande.net>,
   4                   2000-2002 Ivo Timmermans <itimmermans@bigfoot.com>
   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
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20     $Id: subnet.c,v 1.1.2.29 2002/02/10 21:57:54 guus Exp $
  21 */
  22
  23 #include "config.h"
  24
  25 #include <stdio.h>
  26 #include <syslog.h>
  27 #include <string.h>
  28 #include <errno.h>
  29 #include <fcntl.h>
  30 #include <netdb.h>
  31 #include <netinet/in.h>
  32
  33 #include "conf.h"
  34 #include "net.h"
  35 #include "node.h"
  36 #include "subnet.h"
  37 #include "system.h"
  38
  39 #include <utils.h>
  40 #include <xalloc.h>
  41 #include <avl_tree.h>
  42
  43 /* lists type of subnet */
  44
  45 avl_tree_t *subnet_tree;
  46
  47 /* Subnet comparison */
  48
  49 int subnet_compare_mac(subnet_t *a, subnet_t *b)
  50 {
  51 cp
  52   return memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
  53 }
  54
  55 int subnet_compare_ipv4(subnet_t *a, subnet_t *b)
  56 {
  57 cp
  58   /* We compare as if a subnet is a number that equals (address << 32 + netmask). */
  59
  60   if(a->net.ipv4.address < b->net.ipv4.address)
  61     return -1;
  62   else if(a->net.ipv4.address > b->net.ipv4.address)
  63     return 1;
  64
  65   if(a->net.ipv4.mask < b->net.ipv4.mask)
  66     return -1;
  67   else if(a->net.ipv4.mask > b->net.ipv4.mask)
  68     return 1;
  69
  70   return 0;
  71 }
  72
  73 int subnet_compare_ipv6(subnet_t *a, subnet_t *b)
  74 {
  75   int result;
  76 cp
  77   /* Same as ipv4 case, but with nasty 128 bit addresses */
  78
  79   result = memcmp(a->net.ipv6.address.x, b->net.ipv6.address.x, sizeof(ipv6_t));
  80
  81   if(result)
  82     return result;
  83
  84   result = memcmp(a->net.ipv6.mask.x, b->net.ipv6.mask.x, sizeof(ipv6_t));
  85
  86   if(result)
  87     return result;
  88
  89   return 0;
  90 }
  91
  92 int subnet_compare(subnet_t *a, subnet_t *b)
  93 {
  94   int x;
  95 cp
  96   x = a->type - b->type;
  97   if(x)
  98     return x;
  99
 100   switch(a->type)
 101     {
 102       case SUBNET_MAC:
 103         return subnet_compare_mac(a, b);
 104       case SUBNET_IPV4:
 105         return subnet_compare_ipv4(a, b);
 106       case SUBNET_IPV6:
 107         return subnet_compare_ipv6(a, b);
 108       default:
 109         syslog(LOG_ERR, _("subnet_compare() was called with unknown subnet type %d, exitting!"), a->type);
 110         cp_trace();
 111         exit(0);
 112     }
 113
 114   return 0;
 115 }
 116
 117 /* Initialising trees */
 118
 119 void init_subnets(void)
 120 {
 121 cp
 122   subnet_tree = avl_alloc_tree((avl_compare_t)subnet_compare, (avl_action_t)free_subnet);
 123 cp
 124 }
 125
 126 void exit_subnets(void)
 127 {
 128 cp
 129   avl_delete_tree(subnet_tree);
 130 cp
 131 }
 132
 133 avl_tree_t *new_subnet_tree(void)
 134 {
 135 cp
 136   return avl_alloc_tree((avl_compare_t)subnet_compare, NULL);
 137 cp
 138 }
 139
 140 void free_subnet_tree(avl_tree_t *subnet_tree)
 141 {
 142 cp
 143   avl_delete_tree(subnet_tree);
 144 cp
 145 }
 146
 147 /* Allocating and freeing space for subnets */
 148
 149 subnet_t *new_subnet(void)
 150 {
 151 cp
 152   return (subnet_t *)xmalloc(sizeof(subnet_t));
 153 }
 154
 155 void free_subnet(subnet_t *subnet)
 156 {
 157 cp
 158   free(subnet);
 159 }
 160
 161 /* Adding and removing subnets */
 162
 163 void subnet_add(node_t *n, subnet_t *subnet)
 164 {
 165 cp
 166   subnet->owner = n;
 167
 168   avl_insert(subnet_tree, subnet);
 169 cp
 170   avl_insert(n->subnet_tree, subnet);
 171 cp
 172 }
 173
 174 void subnet_del(node_t *n, subnet_t *subnet)
 175 {
 176 cp
 177   avl_delete(n->subnet_tree, subnet);
 178 cp
 179   avl_delete(subnet_tree, subnet);
 180 cp
 181 }
 182
 183 /* Ascii representation of subnets */
 184
 185 subnet_t *str2net(char *subnetstr)
 186 {
 187   int i, l;
 188   subnet_t *subnet;
 189   unsigned short int x[6];
 190 cp
 191   subnet = new_subnet();
 192 cp
 193   if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d",
 194               &x[0],
 195               &x[1],
 196               &x[2],
 197               &x[3],
 198               &subnet->net.ipv4.masklength) == 5)
 199     {
 200       subnet->type = SUBNET_IPV4;
 201       subnet->net.ipv4.address = (((((x[0] << 8) + x[1]) << 8) + x[2]) << 8) + x[3];
 202       subnet->net.ipv4.mask = ~((1 << (32 - subnet->net.ipv4.masklength)) - 1);
 203       return subnet;
 204     }
 205
 206   if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d",
 207              &subnet->net.ipv6.address.x[0],
 208              &subnet->net.ipv6.address.x[1],
 209              &subnet->net.ipv6.address.x[2],
 210              &subnet->net.ipv6.address.x[3],
 211              &subnet->net.ipv6.address.x[4],
 212              &subnet->net.ipv6.address.x[5],
 213              &subnet->net.ipv6.address.x[6],
 214              &subnet->net.ipv6.address.x[7],
 215              &subnet->net.ipv6.masklength) == 9)
 216     {
 217       subnet->type = SUBNET_IPV6;
 218       for(l = subnet->net.ipv6.masklength, i = 0; i < 8; l -= 16, i++)
 219       {
 220         subnet->net.ipv6.address.x[i] = htons(subnet->net.ipv6.address.x[i]);
 221         if(l >= 16)
 222           subnet->net.ipv6.mask.x[i] = 65535;
 223         else if (l > 0)
 224           subnet->net.ipv6.mask.x[i] = htons(65536 - (1 << l));
 225         else
 226           subnet->net.ipv6.mask.x[i] = 0;
 227       }
 228       return subnet;
 229     }
 230
 231   if(sscanf(subnetstr, "%hu.%hu.%hu.%hu",
 232               &x[0],
 233               &x[1],
 234               &x[2],
 235               &x[3]) == 4)
 236     {
 237       subnet->type = SUBNET_IPV4;
 238       subnet->net.ipv4.address = (((((x[0] << 8) + x[1]) << 8) + x[2]) << 8) + x[3];
 239       subnet->net.ipv4.mask = ~0;
 240       subnet->net.ipv4.masklength = 32;
 241       return subnet;
 242     }
 243
 244   if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
 245              &subnet->net.ipv6.address.x[0],
 246              &subnet->net.ipv6.address.x[1],
 247              &subnet->net.ipv6.address.x[2],
 248              &subnet->net.ipv6.address.x[3],
 249              &subnet->net.ipv6.address.x[4],
 250              &subnet->net.ipv6.address.x[5],
 251              &subnet->net.ipv6.address.x[6],
 252              &subnet->net.ipv6.address.x[7]) == 8)
 253     {
 254       subnet->type = SUBNET_IPV6;
 255       subnet->net.ipv6.masklength = 128;
 256       for(l = subnet->net.ipv6.masklength, i = 0; i < 8; l -= 16, i++)
 257       {
 258         subnet->net.ipv6.address.x[i] = htons(subnet->net.ipv6.address.x[i]);
 259         if(l >= 16)
 260           subnet->net.ipv6.mask.x[i] = 65535;
 261         else if (l > 0)
 262           subnet->net.ipv6.mask.x[i] = htons(65536 - (1 << l));
 263         else
 264           subnet->net.ipv6.mask.x[i] = 0;
 265       }
 266       return subnet;
 267     }
 268
 269   if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx",
 270               &x[0],
 271               &x[1],
 272               &x[2],
 273               &x[3],
 274               &x[4],
 275               &x[5]) == 6)
 276     {
 277       subnet->type = SUBNET_MAC;
 278       subnet->net.mac.address.x[0] = x[0];
 279       subnet->net.mac.address.x[1] = x[1];
 280       subnet->net.mac.address.x[2] = x[2];
 281       subnet->net.mac.address.x[3] = x[3];
 282       subnet->net.mac.address.x[4] = x[4];
 283       subnet->net.mac.address.x[5] = x[5];
 284       return subnet;
 285     }
 286
 287   free(subnet);
 288   return NULL;
 289 }
 290
 291 char *net2str(subnet_t *subnet)
 292 {
 293   char *netstr;
 294 cp
 295   switch(subnet->type)
 296     {
 297       case SUBNET_MAC:
 298         asprintf(&netstr, "%hx:%hx:%hx:%hx:%hx:%hx",
 299                    subnet->net.mac.address.x[0],
 300                    subnet->net.mac.address.x[1],
 301                    subnet->net.mac.address.x[2],
 302                    subnet->net.mac.address.x[3],
 303                    subnet->net.mac.address.x[4],
 304                    subnet->net.mac.address.x[5]);
 305         break;
 306       case SUBNET_IPV4:
 307         asprintf(&netstr, "%hu.%hu.%hu.%hu/%d",
 308                    (unsigned short int)((subnet->net.ipv4.address >> 24) & 255),
 309                    (unsigned short int)((subnet->net.ipv4.address >> 16) & 255),
 310                    (unsigned short int)((subnet->net.ipv4.address >> 8) & 255),
 311                    (unsigned short int)(subnet->net.ipv4.address & 255),
 312                    subnet->net.ipv4.masklength);
 313         break;
 314       case SUBNET_IPV6:
 315         asprintf(&netstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d",
 316                    ntohs(subnet->net.ipv6.address.x[0]),
 317                    ntohs(subnet->net.ipv6.address.x[1]),
 318                    ntohs(subnet->net.ipv6.address.x[2]),
 319                    ntohs(subnet->net.ipv6.address.x[3]),
 320                    ntohs(subnet->net.ipv6.address.x[4]),
 321                    ntohs(subnet->net.ipv6.address.x[5]),
 322                    ntohs(subnet->net.ipv6.address.x[6]),
 323                    ntohs(subnet->net.ipv6.address.x[7]),
 324                    subnet->net.ipv6.masklength);
 325         break;
 326       default:
 327         asprintf(&netstr, _("unknown subnet type"));
 328     }
 329 cp
 330   return netstr;
 331 }
 332
 333 /* Subnet lookup routines */
 334
 335 subnet_t *lookup_subnet(node_t *owner, subnet_t *subnet)
 336 {
 337 cp
 338   return avl_search(owner->subnet_tree, subnet);
 339 }
 340
 341 subnet_t *lookup_subnet_mac(mac_t *address)
 342 {
 343   subnet_t subnet, *p;
 344 cp
 345   subnet.type = SUBNET_MAC;
 346   memcpy(&subnet.net.mac.address, address, sizeof(mac_t));
 347
 348   p = (subnet_t *)avl_search(subnet_tree, &subnet);
 349 cp
 350   return p;
 351 }
 352
 353 subnet_t *lookup_subnet_ipv4(ipv4_t *address)
 354 {
 355   subnet_t subnet, *p;
 356 cp
 357   subnet.type = SUBNET_IPV4;
 358   subnet.net.ipv4.address = *address;
 359   subnet.net.ipv4.mask = 0xFFFFFFFF;
 360
 361   do
 362   {
 363     /* Go find subnet */
 364
 365     p = (subnet_t *)avl_search_closest_smaller(subnet_tree, &subnet);
 366
 367   /* Check if the found subnet REALLY matches */
 368 cp
 369     if(p)
 370       {
 371         if ((*address & p->net.ipv4.mask) == p->net.ipv4.address)
 372           break;
 373         else
 374           {
 375             /* Otherwise, see if there is a bigger enclosing subnet */
 376
 377             subnet.net.ipv4.mask = p->net.ipv4.mask << 1;
 378             subnet.net.ipv4.address = p->net.ipv4.address & subnet.net.ipv4.mask;
 379           }
 380       }
 381    } while (p);
 382
 383    return p;
 384 }
 385
 386 subnet_t *lookup_subnet_ipv6(ipv6_t *address)
 387 {
 388   subnet_t subnet, *p;
 389   int i;
 390 cp
 391   subnet.type = SUBNET_IPV6;
 392   memcpy(subnet.net.ipv6.address.x, address, sizeof(ipv6_t));
 393   memset(subnet.net.ipv6.mask.x, 0xFF, 16);
 394
 395   p = (subnet_t *)avl_search_closest_greater(subnet_tree, &subnet);
 396
 397   if(p)
 398     for(i=0; i<8; i++)
 399       if((address->x[i] & p->net.ipv6.address.x[i]) != p->net.ipv6.address.x[i])
 400         return NULL;
 401
 402   return p;
 403 }
 404
 405 void dump_subnets(void)
 406 {
 407   char *netstr;
 408   subnet_t *subnet;
 409   avl_node_t *node;
 410 cp
 411   syslog(LOG_DEBUG, _("Subnet list:"));
 412   for(node = subnet_tree->head; node; node = node->next)
 413     {
 414       subnet = (subnet_t *)node->data;
 415       netstr = net2str(subnet);
 416       syslog(LOG_DEBUG, _(" %s owner %s"), netstr, subnet->owner->name);
 417       free(netstr);
 418     }
 419   syslog(LOG_DEBUG, _("End of subnet list."));
 420 cp
 421 }