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 1.1.2.23 2001/06/29 13:09:55 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     return a->net.ipv4.mask - b->net.ipv4.mask;
  65   else
  66     return a->net.ipv4.address - b->net.ipv4.address;
  67 }
  68
  69 int subnet_compare_ipv6(subnet_t *a, subnet_t *b)
  70 {
  71 cp
  72   /* Same as ipv4 case, but with nasty 128 bit addresses */
  73
  74   if(memcmp(&a->net.ipv6.mask, &b->net.ipv6.mask, sizeof(ipv6_t)) > 0)
  75     if((a->net.ipv6.address.x[0] & b->net.ipv6.mask.x[0]) == b->net.ipv6.address.x[0] &&
  76        (a->net.ipv6.address.x[1] & b->net.ipv6.mask.x[1]) == b->net.ipv6.address.x[1] &&
  77        (a->net.ipv6.address.x[2] & b->net.ipv6.mask.x[2]) == b->net.ipv6.address.x[2] &&
  78        (a->net.ipv6.address.x[3] & b->net.ipv6.mask.x[3]) == b->net.ipv6.address.x[3] &&
  79        (a->net.ipv6.address.x[4] & b->net.ipv6.mask.x[4]) == b->net.ipv6.address.x[4] &&
  80        (a->net.ipv6.address.x[5] & b->net.ipv6.mask.x[5]) == b->net.ipv6.address.x[5] &&
  81        (a->net.ipv6.address.x[6] & b->net.ipv6.mask.x[6]) == b->net.ipv6.address.x[6] &&
  82        (a->net.ipv6.address.x[7] & b->net.ipv6.mask.x[7]) == b->net.ipv6.address.x[7])
  83       return -1;
  84
  85   return memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
  86 }
  87
  88 int subnet_compare(subnet_t *a, subnet_t *b)
  89 {
  90   int x;
  91 cp
  92   x = a->type - b->type;
  93   if(x)
  94     return x;
  95
  96   switch(a->type)
  97     {
  98       case SUBNET_MAC:
  99         return subnet_compare_mac(a, b);
 100       case SUBNET_IPV4:
 101         return subnet_compare_ipv4(a, b);
 102       case SUBNET_IPV6:
 103         return subnet_compare_ipv6(a, b);
 104       default:
 105         syslog(LOG_ERR, _("subnet_compare() was called with unknown subnet type %d, restarting!"), a->type);
 106         sighup = 1;
 107         return 0;
 108     }
 109 }
 110
 111 /* Allocating and freeing space for subnets */
 112
 113 subnet_t *new_subnet(void)
 114 {
 115 cp
 116   return (subnet_t *)xmalloc(sizeof(subnet_t));
 117 }
 118
 119 void free_subnet(subnet_t *subnet)
 120 {
 121 cp
 122   free(subnet);
 123 }
 124
 125 /* Linked list management */
 126
 127 void subnet_add(connection_t *cl, subnet_t *subnet)
 128 {
 129 cp
 130   subnet->owner = cl;
 131
 132   while(!avl_insert(subnet_tree, subnet))
 133     {
 134       subnet_t *old;
 135
 136       old = (subnet_t *)avl_search(subnet_tree, subnet);
 137
 138       if(debug_lvl >= DEBUG_PROTOCOL)
 139         {
 140           char *subnetstr;
 141           subnetstr = net2str(subnet);
 142           syslog(LOG_WARNING, _("Duplicate subnet %s for %s (%s), previous owner %s (%s)!"),
 143                  subnetstr, cl->name, cl->hostname, old->owner->name, old->owner->hostname);
 144           free(subnetstr);
 145         }
 146
 147       subnet_del(old);
 148     }
 149
 150   avl_insert(cl->subnet_tree, subnet);
 151 cp
 152 }
 153
 154 void subnet_del(subnet_t *subnet)
 155 {
 156 cp
 157   avl_delete(subnet->owner->subnet_tree, subnet);
 158 cp
 159   avl_delete(subnet_tree, subnet);
 160 cp
 161 }
 162
 163 /* Ascii representation of subnets */
 164
 165 subnet_t *str2net(char *subnetstr)
 166 {
 167   int type;
 168   subnet_t *subnet;
 169 cp
 170   if(sscanf(subnetstr, "%d,", &type) != 1)
 171     return NULL;
 172 cp
 173   subnet = new_subnet();
 174 cp
 175   switch(type)
 176     {
 177       case SUBNET_MAC:
 178         if(sscanf(subnetstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &subnet->type,
 179                    &subnet->net.mac.address.x[0],
 180                    &subnet->net.mac.address.x[1],
 181                    &subnet->net.mac.address.x[2],
 182                    &subnet->net.mac.address.x[3],
 183                    &subnet->net.mac.address.x[4],
 184                    &subnet->net.mac.address.x[5]) != 7)
 185           {
 186             free_subnet(subnet);
 187             return NULL;
 188           }
 189         break;
 190       case SUBNET_IPV4:
 191         if(sscanf(subnetstr, "%d,%lx/%lx", &subnet->type, &subnet->net.ipv4.address, &subnet->net.ipv4.mask) != 3)
 192           {
 193             free_subnet(subnet);
 194             return NULL;
 195           }
 196         break;
 197       case SUBNET_IPV6:
 198         if(sscanf(subnetstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", &subnet->type,
 199                    &subnet->net.ipv6.address.x[0],
 200                    &subnet->net.ipv6.address.x[1],
 201                    &subnet->net.ipv6.address.x[2],
 202                    &subnet->net.ipv6.address.x[3],
 203                    &subnet->net.ipv6.address.x[4],
 204                    &subnet->net.ipv6.address.x[5],
 205                    &subnet->net.ipv6.address.x[6],
 206                    &subnet->net.ipv6.address.x[7],
 207                    &subnet->net.ipv6.mask.x[0],
 208                    &subnet->net.ipv6.mask.x[1],
 209                    &subnet->net.ipv6.mask.x[2],
 210                    &subnet->net.ipv6.mask.x[3],
 211                    &subnet->net.ipv6.mask.x[4],
 212                    &subnet->net.ipv6.mask.x[5],
 213                    &subnet->net.ipv6.mask.x[6],
 214                    &subnet->net.ipv6.mask.x[7]) != 17)
 215           {
 216             free_subnet(subnet);
 217             return NULL;
 218           }
 219         break;
 220       default:
 221         free_subnet(subnet);
 222         return NULL;
 223     }
 224 cp
 225   return subnet;
 226 }
 227
 228 char *net2str(subnet_t *subnet)
 229 {
 230   char *netstr;
 231 cp
 232   switch(subnet->type)
 233     {
 234       case SUBNET_MAC:
 235         asprintf(&netstr, "%d,%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", subnet->type,
 236                    subnet->net.mac.address.x[0],
 237                    subnet->net.mac.address.x[1],
 238                    subnet->net.mac.address.x[2],
 239                    subnet->net.mac.address.x[3],
 240                    subnet->net.mac.address.x[4],
 241                    subnet->net.mac.address.x[5]);
 242         break;
 243       case SUBNET_IPV4:
 244         asprintf(&netstr, "%d,%lx/%lx", subnet->type, subnet->net.ipv4.address, subnet->net.ipv4.mask);
 245         break;
 246       case SUBNET_IPV6:
 247         asprintf(&netstr, "%d,%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", subnet->type,
 248                    subnet->net.ipv6.address.x[0],
 249                    subnet->net.ipv6.address.x[1],
 250                    subnet->net.ipv6.address.x[2],
 251                    subnet->net.ipv6.address.x[3],
 252                    subnet->net.ipv6.address.x[4],
 253                    subnet->net.ipv6.address.x[5],
 254                    subnet->net.ipv6.address.x[6],
 255                    subnet->net.ipv6.address.x[7],
 256                    subnet->net.ipv6.mask.x[0],
 257                    subnet->net.ipv6.mask.x[1],
 258                    subnet->net.ipv6.mask.x[2],
 259                    subnet->net.ipv6.mask.x[3],
 260                    subnet->net.ipv6.mask.x[4],
 261                    subnet->net.ipv6.mask.x[5],
 262                    subnet->net.ipv6.mask.x[6],
 263                    subnet->net.ipv6.mask.x[7]);
 264         break;
 265       default:
 266         asprintf(&netstr, _("unknown subnet type"));
 267     }
 268 cp
 269   return netstr;
 270 }
 271
 272 /* Subnet lookup routines */
 273
 274 subnet_t *lookup_subnet_mac(mac_t *address)
 275 {
 276   subnet_t subnet, *p;
 277 cp
 278   subnet.type = SUBNET_MAC;
 279   memcpy(&subnet.net.mac.address, address, sizeof(mac_t));
 280
 281   p = (subnet_t *)avl_search(subnet_tree, &subnet);
 282 cp
 283   return p;
 284 }
 285
 286 subnet_t *lookup_subnet_ipv4(ipv4_t *address)
 287 {
 288   subnet_t subnet, *p;
 289 cp
 290   subnet.type = SUBNET_IPV4;
 291   subnet.net.ipv4.address = *address;
 292   subnet.net.ipv4.mask = 0xFFFFFFFF;
 293
 294   do
 295   {
 296     /* Go find subnet */
 297
 298     p = (subnet_t *)avl_search_closest_smaller(subnet_tree, &subnet);
 299
 300   /* Check if the found subnet REALLY matches */
 301 cp
 302     if(p)
 303       {
 304         if ((*address & p->net.ipv4.mask) == p->net.ipv4.address)
 305           break;
 306         else
 307           {
 308             /* Otherwise, see if there is a bigger enclosing subnet */
 309
 310             subnet.net.ipv4.mask = p->net.ipv4.mask << 1;
 311             subnet.net.ipv4.address = p->net.ipv4.address & subnet.net.ipv4.mask;
 312           }
 313       }
 314    } while (p);
 315
 316    return p;
 317 }
 318
 319 subnet_t *lookup_subnet_ipv6(ipv6_t *address)
 320 {
 321   subnet_t subnet, *p;
 322   int i;
 323 cp
 324   subnet.type = SUBNET_IPV6;
 325   memcpy(&subnet.net.ipv6.address, address, sizeof(ipv6_t));
 326   memset(&subnet.net.ipv6.mask, 0xFF, 16);
 327
 328   p = (subnet_t *)avl_search_closest_greater(subnet_tree, &subnet);
 329
 330   if(p)
 331     for(i=0; i<8; i++)
 332       if((address->x[i] & p->net.ipv6.address.x[i]) != p->net.ipv6.address.x[i])
 333         return NULL;
 334
 335   return p;
 336 }
 337
 338 void dump_subnet_list(void)
 339 {
 340   char *netstr;
 341   subnet_t *subnet;
 342   avl_node_t *node;
 343 cp
 344   syslog(LOG_DEBUG, _("Subnet list:"));
 345   for(node = subnet_tree->head; node; node = node->next)
 346     {
 347       subnet = (subnet_t *)node->data;
 348       netstr = net2str(subnet);
 349       syslog(LOG_DEBUG, " %s owner %s", netstr, subnet->owner->name);
 350       free(netstr);
 351     }
 352   syslog(LOG_DEBUG, _("End of subnet list."));
 353 cp
 354 }