source/nmbd/nmbd_winsproxy.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    NBT netbios routines and daemon - version 2
   4
   5    Copyright (C) Jeremy Allison 1994-1998
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 */
  22
  23 #include "includes.h"
  24
  25 /****************************************************************************
  26 Function called when the name lookup succeeded.
  27 ****************************************************************************/
  28
  29 static void wins_proxy_name_query_request_success( struct subnet_record *subrec,
  30                         struct userdata_struct *userdata,
  31                         struct nmb_name *nmbname, struct in_addr ip, struct res_rec *rrec)
  32 {
  33   struct packet_struct *original_packet;
  34   struct subnet_record *orig_broadcast_subnet;
  35   struct name_record *namerec;
  36   uint16 nb_flags;
  37   int num_ips;
  38   int i;
  39   int ttl = 3600; /* By default one hour in the cache. */
  40   struct in_addr *iplist;
  41
  42   /* Extract the original packet and the original broadcast subnet from
  43      the userdata. */
  44
  45   memcpy( (char *)&orig_broadcast_subnet, userdata->data, sizeof(struct subnet_record *) );
  46   memcpy( (char *)&original_packet, &userdata->data[sizeof(struct subnet_record *)],
  47           sizeof(struct packet_struct *) );
  48
  49   nb_flags = get_nb_flags( rrec->rdata );
  50
  51   num_ips = rrec->rdlength / 6;
  52   if(num_ips == 0)
  53   {
  54     DEBUG(0,("wins_proxy_name_query_request_success: Invalid number of IP records (0) \
  55 returned for name %s.\n", nmb_namestr(nmbname) ));
  56     return;
  57   }
  58
  59   if(num_ips == 1)
  60     iplist = &ip;
  61   else
  62   {
  63     if((iplist = (struct in_addr *)malloc( num_ips * sizeof(struct in_addr) )) == NULL)
  64     {
  65       DEBUG(0,("wins_proxy_name_query_request_success: malloc fail !\n"));
  66       return;
  67     }
  68
  69     for(i = 0; i < num_ips; i++)
  70       putip( (char *)&iplist[i], (char *)&rrec->rdata[ (i*6) + 2]);
  71   }
  72
  73   /* Add the queried name to the original subnet as a WINS_PROXY_NAME. */
  74
  75   if(rrec == PERMANENT_TTL)
  76     ttl = lp_max_ttl();
  77
  78   namerec = add_name_to_subnet( orig_broadcast_subnet, nmbname->name,
  79                                 nmbname->name_type, nb_flags, ttl,
  80                                 WINS_PROXY_NAME, num_ips, iplist );
  81
  82   if(iplist != &ip)
  83     SAFE_FREE(iplist);
  84
  85   /*
  86    * Check that none of the IP addresses we are returning is on the
  87    * same broadcast subnet as the original requesting packet. If it
  88    * is then don't reply (although we still need to add the name
  89    * to the cache) as the actual machine will be replying also
  90    * and we don't want two replies to a broadcast query.
  91    */
  92
  93   if(namerec && original_packet->packet.nmb.header.nm_flags.bcast)
  94   {
  95     for( i = 0; i < namerec->data.num_ips; i++)
  96     {
  97       if( same_net( namerec->data.ip[i],
  98                     orig_broadcast_subnet->myip,
  99                     orig_broadcast_subnet->mask_ip ) )
 100       {
 101         DEBUG( 5, ( "wins_proxy_name_query_request_success: name %s is a WINS \
 102 proxy name and is also on the same subnet (%s) as the requestor. \
 103 Not replying.\n",
 104                     nmb_namestr(&namerec->name),
 105                     orig_broadcast_subnet->subnet_name ) );
 106         return;
 107       }
 108     }
 109   }
 110
 111   /* Finally reply to the original name query. */
 112   reply_netbios_packet(original_packet,                /* Packet to reply to. */
 113                        0,                              /* Result code. */
 114                        NMB_QUERY,                      /* nmbd type code. */
 115                        NMB_NAME_QUERY_OPCODE,          /* opcode. */
 116                        ttl,                            /* ttl. */
 117                        rrec->rdata,                    /* data to send. */
 118                        rrec->rdlength);                /* data length. */
 119 }
 120
 121 /****************************************************************************
 122 Function called when the name lookup failed.
 123 ****************************************************************************/
 124
 125 static void wins_proxy_name_query_request_fail(struct subnet_record *subrec,
 126                                     struct response_record *rrec,
 127                                     struct nmb_name *question_name, int fail_code)
 128 {
 129   DEBUG(4,("wins_proxy_name_query_request_fail: WINS server returned error code %d for lookup \
 130 of name %s.\n", fail_code, nmb_namestr(question_name) ));
 131 }
 132
 133 /****************************************************************************
 134 Function to make a deep copy of the userdata we will need when the WINS
 135 proxy query returns.
 136 ****************************************************************************/
 137
 138 static struct userdata_struct *wins_proxy_userdata_copy_fn(struct userdata_struct *userdata)
 139 {
 140   struct packet_struct *p, *copy_of_p;
 141   struct userdata_struct *new_userdata =
 142         (struct userdata_struct *)malloc( userdata->userdata_len );
 143
 144   if(new_userdata == NULL)
 145     return NULL;
 146
 147   new_userdata->copy_fn = userdata->copy_fn;
 148   new_userdata->free_fn = userdata->free_fn;
 149   new_userdata->userdata_len = userdata->userdata_len;
 150
 151   /* Copy the subnet_record pointer. */
 152   memcpy( new_userdata->data, userdata->data, sizeof(struct subnet_record *) );
 153
 154   /* Extract the pointer to the packet struct */
 155   memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
 156          sizeof(struct packet_struct *) );
 157
 158   /* Do a deep copy of the packet. */
 159   if((copy_of_p = copy_packet(p)) == NULL)
 160   {
 161     SAFE_FREE(new_userdata);
 162     return NULL;
 163   }
 164
 165   /* Lock the copy. */
 166   copy_of_p->locked = True;
 167
 168   memcpy( &new_userdata->data[sizeof(struct subnet_record *)], (char *)&copy_of_p,
 169           sizeof(struct packet_struct *) );
 170
 171   return new_userdata;
 172 }
 173
 174 /****************************************************************************
 175 Function to free the deep copy of the userdata we used when the WINS
 176 proxy query returned.
 177 ****************************************************************************/
 178
 179 static void wins_proxy_userdata_free_fn(struct userdata_struct *userdata)
 180 {
 181   struct packet_struct *p;
 182
 183   /* Extract the pointer to the packet struct */
 184   memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
 185          sizeof(struct packet_struct *));
 186
 187   /* Unlock the packet. */
 188   p->locked = False;
 189
 190   free_packet(p);
 191   ZERO_STRUCTP(userdata);
 192   SAFE_FREE(userdata);
 193 }
 194
 195 /****************************************************************************
 196  Make a WINS query on behalf of a broadcast client name query request.
 197 ****************************************************************************/
 198
 199 void make_wins_proxy_name_query_request( struct subnet_record *subrec,
 200                                          struct packet_struct *incoming_packet,
 201                                          struct nmb_name *question_name)
 202 {
 203   long *ud[(sizeof(struct userdata_struct) + sizeof(struct subrec *) +
 204           sizeof(struct packet_struct *))/sizeof(long *) + 1];
 205   struct userdata_struct *userdata = (struct userdata_struct *)ud;
 206
 207   memset(ud, '\0', sizeof(ud));
 208
 209   userdata->copy_fn = wins_proxy_userdata_copy_fn;
 210   userdata->free_fn = wins_proxy_userdata_free_fn;
 211   userdata->userdata_len = sizeof(ud);
 212   memcpy( userdata->data, (char *)&subrec, sizeof(struct subnet_record *));
 213   memcpy( &userdata->data[sizeof(struct subnet_record *)], (char *)&incoming_packet,
 214           sizeof(struct packet_struct *));
 215
 216   /* Now use the unicast subnet to query the name with the WINS server. */
 217   query_name( unicast_subnet, question_name->name, question_name->name_type,
 218               wins_proxy_name_query_request_success,
 219               wins_proxy_name_query_request_fail,
 220               userdata);
 221 }