source4/nbt_server/query.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    answer name queries
   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   answer a name query
  32 */
  33 void nbtd_request_query(struct nbt_name_socket *nbtsock,
  34                         struct nbt_name_packet *packet,
  35                         struct socket_address *src)
  36 {
  37         struct nbtd_iface_name *iname;
  38         struct nbt_name *name;
  39         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  40                                                        struct nbtd_interface);
  41
  42         /* see if its a node status query */
  43         if (packet->qdcount == 1 &&
  44             packet->questions[0].question_type == NBT_QTYPE_STATUS) {
  45                 nbtd_query_status(nbtsock, packet, src);
  46                 return;
  47         }
  48
  49         NBTD_ASSERT_PACKET(packet, src, packet->qdcount == 1);
  50         NBTD_ASSERT_PACKET(packet, src,
  51                            packet->questions[0].question_type == NBT_QTYPE_NETBIOS);
  52         NBTD_ASSERT_PACKET(packet, src,
  53                            packet->questions[0].question_class == NBT_QCLASS_IP);
  54
  55         /* see if we have the requested name on this interface */
  56         name = &packet->questions[0].name;
  57
  58         iname = nbtd_find_iname(iface, name, 0);
  59         if (iname == NULL) {
  60                 /* don't send negative replies to broadcast queries */
  61                 if (packet->operation & NBT_FLAG_BROADCAST) {
  62                         return;
  63                 }
  64
  65                 if (packet->operation & NBT_FLAG_RECURSION_DESIRED) {
  66                         nbtd_winsserver_request(nbtsock, packet, src);
  67                         return;
  68                 }
  69
  70                 /* otherwise send a negative reply */
  71                 nbtd_negative_name_query_reply(nbtsock, packet, src);
  72                 return;
  73         }
  74
  75         /*
  76          * normally we should forward all queries with the
  77          * recursion desired flag to the wins server, but this
  78          * breaks are winsclient code, when doing mhomed registrations
  79          */
  80         if (!(packet->operation & NBT_FLAG_BROADCAST) &&
  81            (packet->operation & NBT_FLAG_RECURSION_DESIRED) &&
  82            (iname->nb_flags & NBT_NM_GROUP) &&
  83            lp_wins_support()) {
  84                 nbtd_winsserver_request(nbtsock, packet, src);
  85                 return;
  86         }
  87
  88         /* if the name is not yet active and its a broadcast query then
  89            ignore it for now */
  90         if (!(iname->nb_flags & NBT_NM_ACTIVE) &&
  91             (packet->operation & NBT_FLAG_BROADCAST)) {
  92                 DEBUG(7,("Query for %s from %s - name not active yet on %s\n",
  93                          nbt_name_string(packet, name), src->addr, iface->ip_address));
  94                 return;
  95         }
  96
  97         nbtd_name_query_reply(nbtsock, packet, src,
  98                               &iname->name, iname->ttl, iname->nb_flags,
  99                               nbtd_address_list(iface, packet));
 100 }