source/nmbd/nmbd_winsproxy.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    NBT netbios routines and daemon - version 2
   5
   6    Copyright (C) Jeremy Allison 1994-1998
   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
  24 #include "includes.h"
  25
  26 /****************************************************************************
  27 Function called when the name lookup succeeded.
  28 ****************************************************************************/
  29
  30 static void wins_proxy_name_query_request_success( struct subnet_record *subrec,
  31                         struct userdata_struct *userdata,
  32                         struct nmb_name *nmbname, struct in_addr ip, struct res_rec *rrec)
  33 {
  34   struct packet_struct *original_packet;
  35   struct subnet_record *orig_broadcast_subnet;
  36   struct name_record *namerec;
  37   uint16 nb_flags;
  38   int num_ips;
  39   int i;
  40   int ttl = 3600; /* By default one hour in the cache. */
  41   struct in_addr *iplist;
  42
  43   /* Extract the original packet and the original broadcast subnet from
  44      the userdata. */
  45
  46   memcpy( (char *)&orig_broadcast_subnet, userdata->data, sizeof(struct subnet_record *) );
  47   memcpy( (char *)&original_packet, &userdata->data[sizeof(struct subnet_record *)],
  48           sizeof(struct packet_struct *) );
  49
  50   nb_flags = get_nb_flags( rrec->rdata );
  51
  52   num_ips = rrec->rdlength / 6;
  53   if(num_ips == 0)
  54   {
  55     DEBUG(0,("wins_proxy_name_query_request_success: Invalid number of IP records (0) \
  56 returned for name %s.\n", nmb_namestr(nmbname) ));
  57     return;
  58   }
  59
  60   if(num_ips == 1)
  61     iplist = &ip;
  62   else
  63   {
  64     if((iplist = (struct in_addr *)malloc( num_ips * sizeof(struct in_addr) )) == NULL)
  65     {
  66       DEBUG(0,("wins_proxy_name_query_request_success: malloc fail !\n"));
  67       return;
  68     }
  69
  70     for(i = 0; i < num_ips; i++)
  71       putip( (char *)&iplist[i], (char *)&rrec->rdata[ (i*6) + 2]);
  72   }
  73
  74   /* Add the queried name to the original subnet as a WINS_PROXY_NAME. */
  75
  76   if(rrec == PERMANENT_TTL)
  77     ttl = lp_max_ttl();
  78
  79   namerec = add_name_to_subnet( orig_broadcast_subnet, nmbname->name,
  80                                 nmbname->name_type, nb_flags, ttl,
  81                                 WINS_PROXY_NAME, num_ips, iplist );
  82
  83   if(iplist != &ip)
  84     SAFE_FREE(iplist);
  85
  86   /*
  87    * Check that none of the IP addresses we are returning is on the
  88    * same broadcast subnet as the original requesting packet. If it
  89    * is then don't reply (although we still need to add the name
  90    * to the cache) as the actual machine will be replying also
  91    * and we don't want two replies to a broadcast query.
  92    */
  93
  94   if(namerec && original_packet->packet.nmb.header.nm_flags.bcast)
  95   {
  96     for( i = 0; i < namerec->data.num_ips; i++)
  97     {
  98       if( same_net( namerec->data.ip[i],
  99                     orig_broadcast_subnet->myip,
 100                     orig_broadcast_subnet->mask_ip ) )
 101       {
 102         DEBUG( 5, ( "wins_proxy_name_query_request_success: name %s is a WINS \
 103 proxy name and is also on the same subnet (%s) as the requestor. \
 104 Not replying.\n",
 105                     nmb_namestr(&namerec->name),
 106                     orig_broadcast_subnet->subnet_name ) );
 107         return;
 108       }
 109     }
 110   }
 111
 112   /* Finally reply to the original name query. */
 113   reply_netbios_packet(original_packet,                /* Packet to reply to. */
 114                        0,                              /* Result code. */
 115                        NMB_QUERY,                      /* nmbd type code. */
 116                        NMB_NAME_QUERY_OPCODE,          /* opcode. */
 117                        ttl,                            /* ttl. */
 118                        rrec->rdata,                    /* data to send. */
 119                        rrec->rdlength);                /* data length. */
 120 }
 121
 122 /****************************************************************************
 123 Function called when the name lookup failed.
 124 ****************************************************************************/
 125
 126 static void wins_proxy_name_query_request_fail(struct subnet_record *subrec,
 127                                     struct response_record *rrec,
 128                                     struct nmb_name *question_name, int fail_code)
 129 {
 130   DEBUG(4,("wins_proxy_name_query_request_fail: WINS server returned error code %d for lookup \
 131 of name %s.\n", fail_code, nmb_namestr(question_name) ));
 132 }
 133
 134 /****************************************************************************
 135 Function to make a deep copy of the userdata we will need when the WINS
 136 proxy query returns.
 137 ****************************************************************************/
 138
 139 static struct userdata_struct *wins_proxy_userdata_copy_fn(struct userdata_struct *userdata)
 140 {
 141   struct packet_struct *p, *copy_of_p;
 142   struct userdata_struct *new_userdata =
 143         (struct userdata_struct *)malloc( userdata->userdata_len );
 144
 145   if(new_userdata == NULL)
 146     return NULL;
 147
 148   new_userdata->copy_fn = userdata->copy_fn;
 149   new_userdata->free_fn = userdata->free_fn;
 150   new_userdata->userdata_len = userdata->userdata_len;
 151
 152   /* Copy the subnet_record pointer. */
 153   memcpy( new_userdata->data, userdata->data, sizeof(struct subnet_record *) );
 154
 155   /* Extract the pointer to the packet struct */
 156   memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
 157          sizeof(struct packet_struct *) );
 158
 159   /* Do a deep copy of the packet. */
 160   if((copy_of_p = copy_packet(p)) == NULL)
 161   {
 162     SAFE_FREE(new_userdata);
 163     return NULL;
 164   }
 165
 166   /* Lock the copy. */
 167   copy_of_p->locked = True;
 168
 169   memcpy( &new_userdata->data[sizeof(struct subnet_record *)], (char *)&copy_of_p,
 170           sizeof(struct packet_struct *) );
 171
 172   return new_userdata;
 173 }
 174
 175 /****************************************************************************
 176 Function to free the deep copy of the userdata we used when the WINS
 177 proxy query returned.
 178 ****************************************************************************/
 179
 180 static void wins_proxy_userdata_free_fn(struct userdata_struct *userdata)
 181 {
 182   struct packet_struct *p;
 183
 184   /* Extract the pointer to the packet struct */
 185   memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
 186          sizeof(struct packet_struct *));
 187
 188   /* Unlock the packet. */
 189   p->locked = False;
 190
 191   free_packet(p);
 192   ZERO_STRUCTP(userdata);
 193   SAFE_FREE(userdata);
 194 }
 195
 196 /****************************************************************************
 197  Make a WINS query on behalf of a broadcast client name query request.
 198 ****************************************************************************/
 199
 200 void make_wins_proxy_name_query_request( struct subnet_record *subrec,
 201                                          struct packet_struct *incoming_packet,
 202                                          struct nmb_name *question_name)
 203 {
 204   long *ud[(sizeof(struct userdata_struct) + sizeof(struct subrec *) +
 205           sizeof(struct packet_struct *))/sizeof(long *) + 1];
 206   struct userdata_struct *userdata = (struct userdata_struct *)ud;
 207
 208   memset(ud, '\0', sizeof(ud));
 209
 210   userdata->copy_fn = wins_proxy_userdata_copy_fn;
 211   userdata->free_fn = wins_proxy_userdata_free_fn;
 212   userdata->userdata_len = sizeof(ud);
 213   memcpy( userdata->data, (char *)&subrec, sizeof(struct subnet_record *));
 214   memcpy( &userdata->data[sizeof(struct subnet_record *)], (char *)&incoming_packet,
 215           sizeof(struct packet_struct *));
 216
 217   /* Now use the unicast subnet to query the name with the WINS server. */
 218   query_name( unicast_subnet, question_name->name, question_name->name_type,
 219               wins_proxy_name_query_request_success,
 220               wins_proxy_name_query_request_fail,
 221               userdata);
 222 }