source/nbt_server/defense.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    defend our names against name registration requests
   5
   6    Copyright (C) Andrew Tridgell        2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "dlinklist.h"
  25 #include "system/network.h"
  26 #include "nbt_server/nbt_server.h"
  27 #include "nbt_server/wins/winsserver.h"
  28 #include "librpc/gen_ndr/ndr_nbt.h"
  29 #include "lib/socket/socket.h"
  30
  31
  32 /*
  33   defend our registered names against registration or name refresh
  34   requests
  35 */
  36 void nbtd_request_defense(struct nbt_name_socket *nbtsock,
  37                           struct nbt_name_packet *packet,
  38                           struct socket_address *src)
  39 {
  40         struct nbtd_iface_name *iname;
  41         struct nbt_name *name;
  42         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  43                                                        struct nbtd_interface);
  44
  45         /*
  46          * if the packet comes from one of our interfaces
  47          * it must be our winsclient trying to reach the winsserver
  48          */
  49         if (nbtd_self_packet(nbtsock, packet, src)) {
  50                 nbtd_winsserver_request(nbtsock, packet, src);
  51                 return;
  52         }
  53
  54         NBTD_ASSERT_PACKET(packet, src, packet->qdcount == 1);
  55         NBTD_ASSERT_PACKET(packet, src, packet->arcount == 1);
  56         NBTD_ASSERT_PACKET(packet, src,
  57                            packet->questions[0].question_type == NBT_QTYPE_NETBIOS);
  58         NBTD_ASSERT_PACKET(packet, src,
  59                            packet->questions[0].question_class == NBT_QCLASS_IP);
  60         NBTD_ASSERT_PACKET(packet, src,
  61                           packet->additional[0].rr_type == NBT_QTYPE_NETBIOS);
  62         NBTD_ASSERT_PACKET(packet, src,
  63                           packet->additional[0].rr_class == NBT_QCLASS_IP);
  64         NBTD_ASSERT_PACKET(packet, src,
  65                           packet->additional[0].rdata.netbios.length == 6);
  66
  67         /* see if we have the requested name on this interface */
  68         name = &packet->questions[0].name;
  69
  70         iname = nbtd_find_iname(iface, name, NBT_NM_ACTIVE);
  71         if (iname != NULL &&
  72             !(name->type == NBT_NAME_LOGON || iname->nb_flags & NBT_NM_GROUP)) {
  73                 DEBUG(2,("Defending name %s on %s against %s\n",
  74                          nbt_name_string(packet, name),
  75                          iface->bcast_address, src->addr));
  76                 nbtd_name_registration_reply(nbtsock, packet, src, NBT_RCODE_ACT);
  77         } else {
  78                 nbtd_winsserver_request(nbtsock, packet, src);
  79         }
  80 }