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 "samba/service_task.h"
  28 #include "librpc/gen_ndr/ndr_nbt.h"
  29 #include "lib/socket/socket.h"
  30 #include "param/param.h"
  31
  32 /*
  33   answer a name query
  34 */
  35 void nbtd_request_query(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_data,
  42                                                        struct nbtd_interface);
  43
  44         /* see if its a node status query */
  45         if (packet->qdcount == 1 &&
  46             packet->questions[0].question_type == NBT_QTYPE_STATUS) {
  47                 nbtd_query_status(nbtsock, packet, src);
  48                 return;
  49         }
  50
  51         NBTD_ASSERT_PACKET(packet, src, packet->qdcount == 1);
  52         NBTD_ASSERT_PACKET(packet, src,
  53                            packet->questions[0].question_type == NBT_QTYPE_NETBIOS);
  54         NBTD_ASSERT_PACKET(packet, src,
  55                            packet->questions[0].question_class == NBT_QCLASS_IP);
  56
  57         /* see if we have the requested name on this interface */
  58         name = &packet->questions[0].name;
  59
  60         iname = nbtd_find_iname(iface, name, 0);
  61         if (iname == NULL) {
  62                 /* don't send negative replies to broadcast queries */
  63                 if (packet->operation & NBT_FLAG_BROADCAST) {
  64                         return;
  65                 }
  66
  67                 if (packet->operation & NBT_FLAG_RECURSION_DESIRED) {
  68                         nbtd_winsserver_request(nbtsock, packet, src);
  69                         return;
  70                 }
  71
  72                 /* otherwise send a negative reply */
  73                 nbtd_negative_name_query_reply(nbtsock, packet, src);
  74                 return;
  75         }
  76
  77         /*
  78          * normally we should forward all queries with the
  79          * recursion desired flag to the wins server, but this
  80          * breaks are winsclient code, when doing mhomed registrations
  81          */
  82         if (!(packet->operation & NBT_FLAG_BROADCAST) &&
  83            (packet->operation & NBT_FLAG_RECURSION_DESIRED) &&
  84            (iname->nb_flags & NBT_NM_GROUP) &&
  85            lpcfg_we_are_a_wins_server(iface->nbtsrv->task->lp_ctx)) {
  86                 nbtd_winsserver_request(nbtsock, packet, src);
  87                 return;
  88         }
  89
  90         /* if the name is not yet active and its a broadcast query then
  91            ignore it for now */
  92         if (!(iname->nb_flags & NBT_NM_ACTIVE) &&
  93             (packet->operation & NBT_FLAG_BROADCAST)) {
  94                 DEBUG(7,("Query for %s from %s - name not active yet on %s\n",
  95                          nbt_name_string(packet, name), src->addr, iface->ip_address));
  96                 return;
  97         }
  98
  99         nbtd_name_query_reply(nbtsock, packet, src,
 100                               &iname->name, iname->ttl, iname->nb_flags,
 101                               nbtd_address_list(iface, packet));
 102 }