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 1.1.2.22 2001/06/06 19:11:16 guus Exp $
  21 */
  22
  23 #include "config.h"
  24
  25 #include <stdio.h>
  26 #include <syslog.h>
  27
  28 #include "conf.h"
  29 #include "net.h"
  30 #include "connection.h"
  31 #include "subnet.h"
  32 #include "system.h"
  33
  34 #include <utils.h>
  35 #include <xalloc.h>
  36 #include <avl_tree.h>
  37
  38 /* lists type of subnet */
  39
  40 avl_tree_t *subnet_tree;
  41
  42 void init_subnets(void)
  43 {
  44 cp
  45   subnet_tree = avl_alloc_tree((avl_compare_t)subnet_compare, (avl_action_t)free_subnet);
  46 cp
  47 }
  48
  49 /* Subnet comparison */
  50
  51 int subnet_compare_mac(subnet_t *a, subnet_t *b)
  52 {
  53 cp
  54   return memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
  55 }
  56
  57 int subnet_compare_ipv4(subnet_t *a, subnet_t *b)
  58 {
  59 cp
  60   /* We compare as if a subnet is a number that equals (address << 32 + netmask). */
  61
  62   if(a->net.ipv4.address == b->net.ipv4.address)
  63     return a->net.ipv4.mask - b->net.ipv4.mask;
  64   else
  65     return a->net.ipv4.address - b->net.ipv4.address;
  66 }
  67
  68 int subnet_compare_ipv6(subnet_t *a, subnet_t *b)
  69 {
  70 cp
  71   /* Same as ipv4 case, but with nasty 128 bit addresses */
  72
  73   if(memcmp(&a->net.ipv6.mask, &b->net.ipv6.mask, sizeof(ipv6_t)) > 0)
  74     if((a->net.ipv6.address.x[0] & b->net.ipv6.mask.x[0]) == b->net.ipv6.address.x[0] &&
  75        (a->net.ipv6.address.x[1] & b->net.ipv6.mask.x[1]) == b->net.ipv6.address.x[1] &&
  76        (a->net.ipv6.address.x[2] & b->net.ipv6.mask.x[2]) == b->net.ipv6.address.x[2] &&
  77        (a->net.ipv6.address.x[3] & b->net.ipv6.mask.x[3]) == b->net.ipv6.address.x[3] &&
  78        (a->net.ipv6.address.x[4] & b->net.ipv6.mask.x[4]) == b->net.ipv6.address.x[4] &&
  79        (a->net.ipv6.address.x[5] & b->net.ipv6.mask.x[5]) == b->net.ipv6.address.x[5] &&
  80        (a->net.ipv6.address.x[6] & b->net.ipv6.mask.x[6]) == b->net.ipv6.address.x[6] &&
  81        (a->net.ipv6.address.x[7] & b->net.ipv6.mask.x[7]) == b->net.ipv6.address.x[7])
  82       return -1;
  83
  84   return memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
  85 }
  86
  87 int subnet_compare(subnet_t *a, subnet_t *b)
  88 {
  89   int x;
  90 cp
  91   x = a->type - b->type;
  92   if(x)
  93     return x;
  94
  95   switch(a->type)
  96     {
  97       case SUBNET_MAC:
  98         return subnet_compare_mac(a, b);
  99       case SUBNET_IPV4:
 100         return subnet_compare_ipv4(a, b);
 101       case SUBNET_IPV6:
 102         return subnet_compare_ipv6(a, b);
 103       default:
 104         syslog(LOG_ERR, _("subnet_compare() was called with unknown subnet type %d, restarting!"), a->type);
 105         sighup = 1;
 106         return 0;
 107     }
 108 }
 109
 110 /* Allocating and freeing space for subnets */
 111
 112 subnet_t *new_subnet(void)
 113 {
 114 cp
 115   return (subnet_t *)xmalloc(sizeof(subnet_t));
 116 }
 117
 118 void free_subnet(subnet_t *subnet)
 119 {
 120 cp
 121   free(subnet);
 122 }
 123
 124 /* Linked list management */
 125
 126 void subnet_add(connection_t *cl, subnet_t *subnet)
 127 {
 128 cp
 129   subnet->owner = cl;
 130
 131   while(!avl_insert(subnet_tree, subnet))
 132     {
 133       subnet_t *old;
 134
 135       old = (subnet_t *)avl_search(subnet_tree, subnet);
 136
 137       if(debug_lvl >= DEBUG_PROTOCOL)
 138         {
 139           char *subnetstr;
 140           subnetstr = net2str(subnet);
 141           syslog(LOG_WARNING, _("Duplicate subnet %s for %s (%s), previous owner %s (%s)!"),
 142                  subnetstr, cl->name, cl->hostname, old->owner->name, old->owner->hostname);
 143           free(subnetstr);
 144         }
 145
 146       subnet_del(old);
 147     }
 148
 149   avl_insert(cl->subnet_tree, subnet);
 150 cp
 151 }
 152
 153 void subnet_del(subnet_t *subnet)
 154 {
 155 cp
 156   avl_delete(subnet->owner->subnet_tree, subnet);
 157 cp
 158   avl_delete(subnet_tree, subnet);
 159 cp
 160 }
 161
 162 /* Ascii representation of subnets */
 163
 164 subnet_t *str2net(char *subnetstr)
 165 {
 166   int type;
 167   subnet_t *subnet;
 168 cp
 169   if(sscanf(subnetstr, "%d,", &type) != 1)
 170     return NULL;
 171 cp
 172   subnet = new_subnet();
 173 cp
 174   switch(type)
 175     {
 176       case SUBNET_MAC:
 177         if(sscanf(subnetstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &subnet->type,
 178                    &subnet->net.mac.address.x[0],
 179                    &subnet->net.mac.address.x[1],
 180                    &subnet->net.mac.address.x[2],
 181                    &subnet->net.mac.address.x[3],
 182                    &subnet->net.mac.address.x[4],
 183                    &subnet->net.mac.address.x[5]) != 7)
 184           {
 185             free_subnet(subnet);
 186             return NULL;
 187           }
 188         break;
 189       case SUBNET_IPV4:
 190         if(sscanf(subnetstr, "%d,%lx/%lx", &subnet->type, &subnet->net.ipv4.address, &subnet->net.ipv4.mask) != 3)
 191           {
 192             free_subnet(subnet);
 193             return NULL;
 194           }
 195         break;
 196       case SUBNET_IPV6:
 197         if(sscanf(subnetstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", &subnet->type,
 198                    &subnet->net.ipv6.address.x[0],
 199                    &subnet->net.ipv6.address.x[1],
 200                    &subnet->net.ipv6.address.x[2],
 201                    &subnet->net.ipv6.address.x[3],
 202                    &subnet->net.ipv6.address.x[4],
 203                    &subnet->net.ipv6.address.x[5],
 204                    &subnet->net.ipv6.address.x[6],
 205                    &subnet->net.ipv6.address.x[7],
 206                    &subnet->net.ipv6.mask.x[0],
 207                    &subnet->net.ipv6.mask.x[1],
 208                    &subnet->net.ipv6.mask.x[2],
 209                    &subnet->net.ipv6.mask.x[3],
 210                    &subnet->net.ipv6.mask.x[4],
 211                    &subnet->net.ipv6.mask.x[5],
 212                    &subnet->net.ipv6.mask.x[6],
 213                    &subnet->net.ipv6.mask.x[7]) != 17)
 214           {
 215             free_subnet(subnet);
 216             return NULL;
 217           }
 218         break;
 219       default:
 220         free_subnet(subnet);
 221         return NULL;
 222     }
 223 cp
 224   return subnet;
 225 }
 226
 227 char *net2str(subnet_t *subnet)
 228 {
 229   char *netstr;
 230 cp
 231   switch(subnet->type)
 232     {
 233       case SUBNET_MAC:
 234         asprintf(&netstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", subnet->type,
 235                    subnet->net.mac.address.x[0],
 236                    subnet->net.mac.address.x[1],
 237                    subnet->net.mac.address.x[2],
 238                    subnet->net.mac.address.x[3],
 239                    subnet->net.mac.address.x[4],
 240                    subnet->net.mac.address.x[5]);
 241         break;
 242       case SUBNET_IPV4:
 243         asprintf(&netstr, "%d,%lx/%lx", subnet->type, subnet->net.ipv4.address, subnet->net.ipv4.mask);
 244         break;
 245       case SUBNET_IPV6:
 246         asprintf(&netstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", subnet->type,
 247                    subnet->net.ipv6.address.x[0],
 248                    subnet->net.ipv6.address.x[1],
 249                    subnet->net.ipv6.address.x[2],
 250                    subnet->net.ipv6.address.x[3],
 251                    subnet->net.ipv6.address.x[4],
 252                    subnet->net.ipv6.address.x[5],
 253                    subnet->net.ipv6.address.x[6],
 254                    subnet->net.ipv6.address.x[7],
 255                    subnet->net.ipv6.mask.x[0],
 256                    subnet->net.ipv6.mask.x[1],
 257                    subnet->net.ipv6.mask.x[2],
 258                    subnet->net.ipv6.mask.x[3],
 259                    subnet->net.ipv6.mask.x[4],
 260                    subnet->net.ipv6.mask.x[5],
 261                    subnet->net.ipv6.mask.x[6],
 262                    subnet->net.ipv6.mask.x[7]);
 263         break;
 264       default:
 265         asprintf(&netstr, _("unknown subnet type"));
 266     }
 267 cp
 268   return netstr;
 269 }
 270
 271 /* Subnet lookup routines */
 272
 273 subnet_t *lookup_subnet_mac(mac_t *address)
 274 {
 275   subnet_t subnet, *p;
 276 cp
 277   subnet.type = SUBNET_MAC;
 278   memcpy(&subnet.net.mac.address, address, sizeof(mac_t));
 279
 280   p = (subnet_t *)avl_search(subnet_tree, &subnet);
 281 cp
 282   return p;
 283 }
 284
 285 subnet_t *lookup_subnet_ipv4(ipv4_t *address)
 286 {
 287   subnet_t subnet, *p;
 288 cp
 289   subnet.type = SUBNET_IPV4;
 290   subnet.net.ipv4.address = *address;
 291   subnet.net.ipv4.mask = 0xFFFFFFFF;
 292
 293   do
 294   {
 295     /* Go find subnet */
 296
 297     p = (subnet_t *)avl_search_closest_smaller(subnet_tree, &subnet);
 298
 299   /* Check if the found subnet REALLY matches */
 300 cp
 301     if(p)
 302       {
 303         if ((*address & p->net.ipv4.mask) == p->net.ipv4.address)
 304           break;
 305         else
 306           {
 307             /* Otherwise, see if there is a bigger enclosing subnet */
 308
 309             subnet.net.ipv4.mask = p->net.ipv4.mask << 1;
 310             subnet.net.ipv4.address = p->net.ipv4.address & subnet.net.ipv4.mask;
 311           }
 312       }
 313    } while (p);
 314
 315    return p;
 316 }
 317
 318 subnet_t *lookup_subnet_ipv6(ipv6_t *address)
 319 {
 320   subnet_t subnet, *p;
 321   int i;
 322 cp
 323   subnet.type = SUBNET_IPV6;
 324   memcpy(&subnet.net.ipv6.address, address, sizeof(ipv6_t));
 325   memset(&subnet.net.ipv6.mask, 0xFF, 16);
 326
 327   p = (subnet_t *)avl_search_closest_greater(subnet_tree, &subnet);
 328
 329   if(p)
 330     for(i=0; i<8; i++)
 331       if((address->x[i] & p->net.ipv6.address.x[i]) != p->net.ipv6.address.x[i])
 332         return NULL;
 333
 334   return p;
 335 }
 336
 337 void dump_subnet_list(void)
 338 {
 339   char *netstr;
 340   subnet_t *subnet;
 341   avl_node_t *node;
 342 cp
 343   syslog(LOG_DEBUG, _("Subnet list:"));
 344   for(node = subnet_tree->head; node; node = node->next)
 345     {
 346       subnet = (subnet_t *)node->data;
 347       netstr = net2str(subnet);
 348       syslog(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 349       free(netstr);
 350     }
 351   syslog(LOG_DEBUG, _("End of subnet list."));
 352 cp
 353 }