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

   1 /*
   2     subnet.c -- handle subnet lookups and lists
   3     Copyright (C) 2000,2001 Guus Sliepen <guus@sliepen.warande.net>,
   4                   2000,2001 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 1.1.2.24 2001/08/28 20:52:39 guus Exp $
  21 */
  22
  23 #include "config.h"
  24
  25 #include <stdio.h>
  26 #include <syslog.h>
  27 #include <string.h>
  28
  29 #include "conf.h"
  30 #include "net.h"
  31 #include "connection.h"
  32 #include "subnet.h"
  33 #include "system.h"
  34
  35 #include <utils.h>
  36 #include <xalloc.h>
  37 #include <avl_tree.h>
  38
  39 /* lists type of subnet */
  40
  41 avl_tree_t *subnet_tree;
  42
  43 void init_subnets(void)
  44 {
  45 cp
  46   subnet_tree = avl_alloc_tree((avl_compare_t)subnet_compare, (avl_action_t)free_subnet);
  47 cp
  48 }
  49
  50 /* Subnet comparison */
  51
  52 int subnet_compare_mac(subnet_t *a, subnet_t *b)
  53 {
  54 cp
  55   return memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
  56 }
  57
  58 int subnet_compare_ipv4(subnet_t *a, subnet_t *b)
  59 {
  60 cp
  61   /* We compare as if a subnet is a number that equals (address << 32 + netmask). */
  62
  63   if(a->net.ipv4.address == b->net.ipv4.address)
  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     else
  70       return 0;
  71   }
  72   else
  73   {
  74     if(a->net.ipv4.address < b->net.ipv4.address)
  75       return -1;
  76     else if(a->net.ipv4.address > b->net.ipv4.address)
  77       return 1;
  78     else
  79       return 0;
  80   }
  81 }
  82
  83 int subnet_compare_ipv6(subnet_t *a, subnet_t *b)
  84 {
  85 cp
  86   /* Same as ipv4 case, but with nasty 128 bit addresses */
  87
  88   if(memcmp(&a->net.ipv6.mask, &b->net.ipv6.mask, sizeof(ipv6_t)) > 0)
  89     if((a->net.ipv6.address.x[0] & b->net.ipv6.mask.x[0]) == b->net.ipv6.address.x[0] &&
  90        (a->net.ipv6.address.x[1] & b->net.ipv6.mask.x[1]) == b->net.ipv6.address.x[1] &&
  91        (a->net.ipv6.address.x[2] & b->net.ipv6.mask.x[2]) == b->net.ipv6.address.x[2] &&
  92        (a->net.ipv6.address.x[3] & b->net.ipv6.mask.x[3]) == b->net.ipv6.address.x[3] &&
  93        (a->net.ipv6.address.x[4] & b->net.ipv6.mask.x[4]) == b->net.ipv6.address.x[4] &&
  94        (a->net.ipv6.address.x[5] & b->net.ipv6.mask.x[5]) == b->net.ipv6.address.x[5] &&
  95        (a->net.ipv6.address.x[6] & b->net.ipv6.mask.x[6]) == b->net.ipv6.address.x[6] &&
  96        (a->net.ipv6.address.x[7] & b->net.ipv6.mask.x[7]) == b->net.ipv6.address.x[7])
  97       return -1;
  98
  99   return memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
 100 }
 101
 102 int subnet_compare(subnet_t *a, subnet_t *b)
 103 {
 104   int x;
 105 cp
 106   x = a->type - b->type;
 107   if(x)
 108     return x;
 109
 110   switch(a->type)
 111     {
 112       case SUBNET_MAC:
 113         return subnet_compare_mac(a, b);
 114       case SUBNET_IPV4:
 115         return subnet_compare_ipv4(a, b);
 116       case SUBNET_IPV6:
 117         return subnet_compare_ipv6(a, b);
 118       default:
 119         syslog(LOG_ERR, _("subnet_compare() was called with unknown subnet type %d, restarting!"), a->type);
 120         sighup = 1;
 121         return 0;
 122     }
 123 }
 124
 125 /* Allocating and freeing space for subnets */
 126
 127 subnet_t *new_subnet(void)
 128 {
 129 cp
 130   return (subnet_t *)xmalloc(sizeof(subnet_t));
 131 }
 132
 133 void free_subnet(subnet_t *subnet)
 134 {
 135 cp
 136   free(subnet);
 137 }
 138
 139 /* Linked list management */
 140
 141 void subnet_add(connection_t *cl, subnet_t *subnet)
 142 {
 143 cp
 144   subnet->owner = cl;
 145
 146   while(!avl_insert(subnet_tree, subnet))
 147     {
 148       subnet_t *old;
 149
 150       old = (subnet_t *)avl_search(subnet_tree, subnet);
 151
 152       if(debug_lvl >= DEBUG_PROTOCOL)
 153         {
 154           char *subnetstr;
 155           subnetstr = net2str(subnet);
 156           syslog(LOG_WARNING, _("Duplicate subnet %s for %s (%s), previous owner %s (%s)!"),
 157                  subnetstr, cl->name, cl->hostname, old->owner->name, old->owner->hostname);
 158           free(subnetstr);
 159         }
 160
 161       subnet_del(old);
 162     }
 163
 164   avl_insert(cl->subnet_tree, subnet);
 165 cp
 166 }
 167
 168 void subnet_del(subnet_t *subnet)
 169 {
 170 cp
 171   avl_delete(subnet->owner->subnet_tree, subnet);
 172 cp
 173   avl_delete(subnet_tree, subnet);
 174 cp
 175 }
 176
 177 /* Ascii representation of subnets */
 178
 179 subnet_t *str2net(char *subnetstr)
 180 {
 181   int type;
 182   subnet_t *subnet;
 183 cp
 184   if(sscanf(subnetstr, "%d,", &type) != 1)
 185     return NULL;
 186 cp
 187   subnet = new_subnet();
 188 cp
 189   switch(type)
 190     {
 191       case SUBNET_MAC:
 192         if(sscanf(subnetstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &subnet->type,
 193                    &subnet->net.mac.address.x[0],
 194                    &subnet->net.mac.address.x[1],
 195                    &subnet->net.mac.address.x[2],
 196                    &subnet->net.mac.address.x[3],
 197                    &subnet->net.mac.address.x[4],
 198                    &subnet->net.mac.address.x[5]) != 7)
 199           {
 200             free_subnet(subnet);
 201             return NULL;
 202           }
 203         break;
 204       case SUBNET_IPV4:
 205         if(sscanf(subnetstr, "%d,%lx/%lx", &subnet->type, &subnet->net.ipv4.address, &subnet->net.ipv4.mask) != 3)
 206           {
 207             free_subnet(subnet);
 208             return NULL;
 209           }
 210         break;
 211       case SUBNET_IPV6:
 212         if(sscanf(subnetstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", &subnet->type,
 213                    &subnet->net.ipv6.address.x[0],
 214                    &subnet->net.ipv6.address.x[1],
 215                    &subnet->net.ipv6.address.x[2],
 216                    &subnet->net.ipv6.address.x[3],
 217                    &subnet->net.ipv6.address.x[4],
 218                    &subnet->net.ipv6.address.x[5],
 219                    &subnet->net.ipv6.address.x[6],
 220                    &subnet->net.ipv6.address.x[7],
 221                    &subnet->net.ipv6.mask.x[0],
 222                    &subnet->net.ipv6.mask.x[1],
 223                    &subnet->net.ipv6.mask.x[2],
 224                    &subnet->net.ipv6.mask.x[3],
 225                    &subnet->net.ipv6.mask.x[4],
 226                    &subnet->net.ipv6.mask.x[5],
 227                    &subnet->net.ipv6.mask.x[6],
 228                    &subnet->net.ipv6.mask.x[7]) != 17)
 229           {
 230             free_subnet(subnet);
 231             return NULL;
 232           }
 233         break;
 234       default:
 235         free_subnet(subnet);
 236         return NULL;
 237     }
 238 cp
 239   return subnet;
 240 }
 241
 242 char *net2str(subnet_t *subnet)
 243 {
 244   char *netstr;
 245 cp
 246   switch(subnet->type)
 247     {
 248       case SUBNET_MAC:
 249         asprintf(&netstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", subnet->type,
 250                    subnet->net.mac.address.x[0],
 251                    subnet->net.mac.address.x[1],
 252                    subnet->net.mac.address.x[2],
 253                    subnet->net.mac.address.x[3],
 254                    subnet->net.mac.address.x[4],
 255                    subnet->net.mac.address.x[5]);
 256         break;
 257       case SUBNET_IPV4:
 258         asprintf(&netstr, "%d,%lx/%lx", subnet->type, subnet->net.ipv4.address, subnet->net.ipv4.mask);
 259         break;
 260       case SUBNET_IPV6:
 261         asprintf(&netstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", subnet->type,
 262                    subnet->net.ipv6.address.x[0],
 263                    subnet->net.ipv6.address.x[1],
 264                    subnet->net.ipv6.address.x[2],
 265                    subnet->net.ipv6.address.x[3],
 266                    subnet->net.ipv6.address.x[4],
 267                    subnet->net.ipv6.address.x[5],
 268                    subnet->net.ipv6.address.x[6],
 269                    subnet->net.ipv6.address.x[7],
 270                    subnet->net.ipv6.mask.x[0],
 271                    subnet->net.ipv6.mask.x[1],
 272                    subnet->net.ipv6.mask.x[2],
 273                    subnet->net.ipv6.mask.x[3],
 274                    subnet->net.ipv6.mask.x[4],
 275                    subnet->net.ipv6.mask.x[5],
 276                    subnet->net.ipv6.mask.x[6],
 277                    subnet->net.ipv6.mask.x[7]);
 278         break;
 279       default:
 280         asprintf(&netstr, _("unknown subnet type"));
 281     }
 282 cp
 283   return netstr;
 284 }
 285
 286 /* Subnet lookup routines */
 287
 288 subnet_t *lookup_subnet_mac(mac_t *address)
 289 {
 290   subnet_t subnet, *p;
 291 cp
 292   subnet.type = SUBNET_MAC;
 293   memcpy(&subnet.net.mac.address, address, sizeof(mac_t));
 294
 295   p = (subnet_t *)avl_search(subnet_tree, &subnet);
 296 cp
 297   return p;
 298 }
 299
 300 subnet_t *lookup_subnet_ipv4(ipv4_t *address)
 301 {
 302   subnet_t subnet, *p;
 303 cp
 304   subnet.type = SUBNET_IPV4;
 305   subnet.net.ipv4.address = *address;
 306   subnet.net.ipv4.mask = 0xFFFFFFFF;
 307
 308   do
 309   {
 310     /* Go find subnet */
 311
 312     p = (subnet_t *)avl_search_closest_smaller(subnet_tree, &subnet);
 313
 314   /* Check if the found subnet REALLY matches */
 315 cp
 316     if(p)
 317       {
 318         if ((*address & p->net.ipv4.mask) == p->net.ipv4.address)
 319           break;
 320         else
 321           {
 322             /* Otherwise, see if there is a bigger enclosing subnet */
 323
 324             subnet.net.ipv4.mask = p->net.ipv4.mask << 1;
 325             subnet.net.ipv4.address = p->net.ipv4.address & subnet.net.ipv4.mask;
 326           }
 327       }
 328    } while (p);
 329
 330    return p;
 331 }
 332
 333 subnet_t *lookup_subnet_ipv6(ipv6_t *address)
 334 {
 335   subnet_t subnet, *p;
 336   int i;
 337 cp
 338   subnet.type = SUBNET_IPV6;
 339   memcpy(&subnet.net.ipv6.address, address, sizeof(ipv6_t));
 340   memset(&subnet.net.ipv6.mask, 0xFF, 16);
 341
 342   p = (subnet_t *)avl_search_closest_greater(subnet_tree, &subnet);
 343
 344   if(p)
 345     for(i=0; i<8; i++)
 346       if((address->x[i] & p->net.ipv6.address.x[i]) != p->net.ipv6.address.x[i])
 347         return NULL;
 348
 349   return p;
 350 }
 351
 352 void dump_subnet_list(void)
 353 {
 354   char *netstr;
 355   subnet_t *subnet;
 356   avl_node_t *node;
 357 cp
 358   syslog(LOG_DEBUG, _("Subnet list:"));
 359   for(node = subnet_tree->head; node; node = node->next)
 360     {
 361       subnet = (subnet_t *)node->data;
 362       netstr = net2str(subnet);
 363       syslog(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 364       free(netstr);
 365     }
 366   syslog(LOG_DEBUG, _("End of subnet list."));
 367 cp
 368 }