source4/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 3 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, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "lib/util/dlinklist.h"
  24 #include "system/network.h"
  25 #include "nbt_server/nbt_server.h"
  26 #include "nbt_server/wins/winsserver.h"
  27 #include "librpc/gen_ndr/ndr_nbt.h"
  28 #include "lib/socket/socket.h"
  29
  30
  31 /*
  32   defend our registered names against registration or name refresh
  33   requests
  34 */
  35 void nbtd_request_defense(struct nbt_name_socket *nbtsock,
  36                           struct nbt_name_packet *packet,
  37                           struct socket_address *src)
  38 {
  39         struct nbtd_iface_name *iname;
  40         struct nbt_name *name;
  41         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  42                                                        struct nbtd_interface);
  43
  44         /*
  45          * if the packet comes from one of our interfaces
  46          * it must be our winsclient trying to reach the winsserver
  47          */
  48         if (nbtd_self_packet(nbtsock, packet, src)) {
  49                 nbtd_winsserver_request(nbtsock, packet, src);
  50                 return;
  51         }
  52
  53         NBTD_ASSERT_PACKET(packet, src, packet->qdcount == 1);
  54         NBTD_ASSERT_PACKET(packet, src, packet->arcount == 1);
  55         NBTD_ASSERT_PACKET(packet, src,
  56                            packet->questions[0].question_type == NBT_QTYPE_NETBIOS);
  57         NBTD_ASSERT_PACKET(packet, src,
  58                            packet->questions[0].question_class == NBT_QCLASS_IP);
  59         NBTD_ASSERT_PACKET(packet, src,
  60                           packet->additional[0].rr_type == NBT_QTYPE_NETBIOS);
  61         NBTD_ASSERT_PACKET(packet, src,
  62                           packet->additional[0].rr_class == NBT_QCLASS_IP);
  63         NBTD_ASSERT_PACKET(packet, src,
  64                           packet->additional[0].rdata.netbios.length == 6);
  65
  66         /* see if we have the requested name on this interface */
  67         name = &packet->questions[0].name;
  68
  69         iname = nbtd_find_iname(iface, name, NBT_NM_ACTIVE);
  70         if (iname != NULL &&
  71             !(name->type == NBT_NAME_LOGON || iname->nb_flags & NBT_NM_GROUP)) {
  72                 DEBUG(2,("Defending name %s on %s against %s\n",
  73                          nbt_name_string(packet, name),
  74                          iface->bcast_address, src->addr));
  75                 nbtd_name_registration_reply(nbtsock, packet, src, NBT_RCODE_ACT);
  76         } else {
  77                 nbtd_winsserver_request(nbtsock, packet, src);
  78         }
  79 }