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 1.1.2.21 2001/06/05 18:07:14 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   avl_insert(subnet_tree, subnet);
 131   avl_insert(cl->subnet_tree, subnet);
 132 cp
 133 }
 134
 135 void subnet_del(subnet_t *subnet)
 136 {
 137 cp
 138   avl_delete(subnet->owner->subnet_tree, subnet);
 139 cp
 140   avl_delete(subnet_tree, subnet);
 141 cp
 142 }
 143
 144 /* Ascii representation of subnets */
 145
 146 subnet_t *str2net(char *subnetstr)
 147 {
 148   int type;
 149   subnet_t *subnet;
 150 cp
 151   if(sscanf(subnetstr, "%d,", &type) != 1)
 152     return NULL;
 153 cp
 154   subnet = new_subnet();
 155 cp
 156   switch(type)
 157     {
 158       case SUBNET_MAC:
 159         if(sscanf(subnetstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &subnet->type,
 160                    &subnet->net.mac.address.x[0],
 161                    &subnet->net.mac.address.x[1],
 162                    &subnet->net.mac.address.x[2],
 163                    &subnet->net.mac.address.x[3],
 164                    &subnet->net.mac.address.x[4],
 165                    &subnet->net.mac.address.x[5]) != 7)
 166           {
 167             free_subnet(subnet);
 168             return NULL;
 169           }
 170         break;
 171       case SUBNET_IPV4:
 172         if(sscanf(subnetstr, "%d,%lx/%lx", &subnet->type, &subnet->net.ipv4.address, &subnet->net.ipv4.mask) != 3)
 173           {
 174             free_subnet(subnet);
 175             return NULL;
 176           }
 177         break;
 178       case SUBNET_IPV6:
 179         if(sscanf(subnetstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", &subnet->type,
 180                    &subnet->net.ipv6.address.x[0],
 181                    &subnet->net.ipv6.address.x[1],
 182                    &subnet->net.ipv6.address.x[2],
 183                    &subnet->net.ipv6.address.x[3],
 184                    &subnet->net.ipv6.address.x[4],
 185                    &subnet->net.ipv6.address.x[5],
 186                    &subnet->net.ipv6.address.x[6],
 187                    &subnet->net.ipv6.address.x[7],
 188                    &subnet->net.ipv6.mask.x[0],
 189                    &subnet->net.ipv6.mask.x[1],
 190                    &subnet->net.ipv6.mask.x[2],
 191                    &subnet->net.ipv6.mask.x[3],
 192                    &subnet->net.ipv6.mask.x[4],
 193                    &subnet->net.ipv6.mask.x[5],
 194                    &subnet->net.ipv6.mask.x[6],
 195                    &subnet->net.ipv6.mask.x[7]) != 17)
 196           {
 197             free_subnet(subnet);
 198             return NULL;
 199           }
 200         break;
 201       default:
 202         free_subnet(subnet);
 203         return NULL;
 204     }
 205 cp
 206   return subnet;
 207 }
 208
 209 char *net2str(subnet_t *subnet)
 210 {
 211   char *netstr;
 212 cp
 213   switch(subnet->type)
 214     {
 215       case SUBNET_MAC:
 216         asprintf(&netstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", subnet->type,
 217                    subnet->net.mac.address.x[0],
 218                    subnet->net.mac.address.x[1],
 219                    subnet->net.mac.address.x[2],
 220                    subnet->net.mac.address.x[3],
 221                    subnet->net.mac.address.x[4],
 222                    subnet->net.mac.address.x[5]);
 223         break;
 224       case SUBNET_IPV4:
 225         asprintf(&netstr, "%d,%lx/%lx", subnet->type, subnet->net.ipv4.address, subnet->net.ipv4.mask);
 226         break;
 227       case SUBNET_IPV6:
 228         asprintf(&netstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", subnet->type,
 229                    subnet->net.ipv6.address.x[0],
 230                    subnet->net.ipv6.address.x[1],
 231                    subnet->net.ipv6.address.x[2],
 232                    subnet->net.ipv6.address.x[3],
 233                    subnet->net.ipv6.address.x[4],
 234                    subnet->net.ipv6.address.x[5],
 235                    subnet->net.ipv6.address.x[6],
 236                    subnet->net.ipv6.address.x[7],
 237                    subnet->net.ipv6.mask.x[0],
 238                    subnet->net.ipv6.mask.x[1],
 239                    subnet->net.ipv6.mask.x[2],
 240                    subnet->net.ipv6.mask.x[3],
 241                    subnet->net.ipv6.mask.x[4],
 242                    subnet->net.ipv6.mask.x[5],
 243                    subnet->net.ipv6.mask.x[6],
 244                    subnet->net.ipv6.mask.x[7]);
 245         break;
 246       default:
 247         asprintf(&netstr, _("unknown subnet type"));
 248     }
 249 cp
 250   return netstr;
 251 }
 252
 253 /* Subnet lookup routines */
 254
 255 subnet_t *lookup_subnet_mac(mac_t *address)
 256 {
 257   subnet_t subnet, *p;
 258 cp
 259   subnet.type = SUBNET_MAC;
 260   memcpy(&subnet.net.mac.address, address, sizeof(mac_t));
 261
 262   p = (subnet_t *)avl_search(subnet_tree, &subnet);
 263 cp
 264   return p;
 265 }
 266
 267 subnet_t *lookup_subnet_ipv4(ipv4_t *address)
 268 {
 269   subnet_t subnet, *p;
 270 cp
 271   subnet.type = SUBNET_IPV4;
 272   subnet.net.ipv4.address = *address;
 273   subnet.net.ipv4.mask = 0xFFFFFFFF;
 274
 275   do
 276   {
 277     /* Go find subnet */
 278
 279     p = (subnet_t *)avl_search_closest_smaller(subnet_tree, &subnet);
 280
 281   /* Check if the found subnet REALLY matches */
 282 cp
 283     if(p)
 284       {
 285         if ((*address & p->net.ipv4.mask) == p->net.ipv4.address)
 286           break;
 287         else
 288           {
 289             /* Otherwise, see if there is a bigger enclosing subnet */
 290
 291             subnet.net.ipv4.mask = p->net.ipv4.mask << 1;
 292             subnet.net.ipv4.address = p->net.ipv4.address & subnet.net.ipv4.mask;
 293           }
 294       }
 295    } while (p);
 296
 297    return p;
 298 }
 299
 300 subnet_t *lookup_subnet_ipv6(ipv6_t *address)
 301 {
 302   subnet_t subnet, *p;
 303   int i;
 304 cp
 305   subnet.type = SUBNET_IPV6;
 306   memcpy(&subnet.net.ipv6.address, address, sizeof(ipv6_t));
 307   memset(&subnet.net.ipv6.mask, 0xFF, 16);
 308
 309   p = (subnet_t *)avl_search_closest_greater(subnet_tree, &subnet);
 310
 311   if(p)
 312     for(i=0; i<8; i++)
 313       if((address->x[i] & p->net.ipv6.address.x[i]) != p->net.ipv6.address.x[i])
 314         return NULL;
 315
 316   return p;
 317 }
 318
 319 void dump_subnet_list(void)
 320 {
 321   char *netstr;
 322   subnet_t *subnet;
 323   avl_node_t *node;
 324 cp
 325   syslog(LOG_DEBUG, _("Subnet list:"));
 326   for(node = subnet_tree->head; node; node = node->next)
 327     {
 328       subnet = (subnet_t *)node->data;
 329       netstr = net2str(subnet);
 330       syslog(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 331       free(netstr);
 332     }
 333   syslog(LOG_DEBUG, _("End of subnet list."));
 334 cp
 335 }