nmbd_winsproxy.c   [plain text]

/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   NBT netbios routines and daemon - version 2

   Copyright (C) Jeremy Allison 1994-1998

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   
*/

#include "includes.h"

/****************************************************************************
Function called when the name lookup succeeded.
****************************************************************************/

static void wins_proxy_name_query_request_success( struct subnet_record *subrec,
                        struct userdata_struct *userdata,
                        struct nmb_name *nmbname, struct in_addr ip, struct res_rec *rrec)
{
  struct packet_struct *original_packet;
  struct subnet_record *orig_broadcast_subnet;
  struct name_record *namerec;
  uint16 nb_flags;
  int num_ips;
  int i;
  int ttl = 3600; /* By default one hour in the cache. */
  struct in_addr *iplist;

  /* Extract the original packet and the original broadcast subnet from
     the userdata. */

  memcpy( (char *)&orig_broadcast_subnet, userdata->data, sizeof(struct subnet_record *) );
  memcpy( (char *)&original_packet, &userdata->data[sizeof(struct subnet_record *)],
          sizeof(struct packet_struct *) );

  nb_flags = get_nb_flags( rrec->rdata );

  num_ips = rrec->rdlength / 6;
  if(num_ips == 0)
  {
    DEBUG(0,("wins_proxy_name_query_request_success: Invalid number of IP records (0) \
returned for name %s.\n", nmb_namestr(nmbname) ));
    return;
  }

  if(num_ips == 1)
    iplist = &ip;
  else
  {
    if((iplist = (struct in_addr *)malloc( num_ips * sizeof(struct in_addr) )) == NULL)
    {
      DEBUG(0,("wins_proxy_name_query_request_success: malloc fail !\n"));
      return;
    }

    for(i = 0; i < num_ips; i++)
      putip( (char *)&iplist[i], (char *)&rrec->rdata[ (i*6) + 2]);
  }

  /* Add the queried name to the original subnet as a WINS_PROXY_NAME. */

  if(rrec == PERMANENT_TTL)
    ttl = lp_max_ttl();

  namerec = add_name_to_subnet( orig_broadcast_subnet, nmbname->name,
                                nmbname->name_type, nb_flags, ttl,
                                WINS_PROXY_NAME, num_ips, iplist );

  if(iplist != &ip)
    SAFE_FREE(iplist);

  /*
   * Check that none of the IP addresses we are returning is on the
   * same broadcast subnet as the original requesting packet. If it
   * is then don't reply (although we still need to add the name
   * to the cache) as the actual machine will be replying also
   * and we don't want two replies to a broadcast query.
   */

  if(namerec && original_packet->packet.nmb.header.nm_flags.bcast)
  {
    for( i = 0; i < namerec->data.num_ips; i++)
    {
      if( same_net( namerec->data.ip[i],
                    orig_broadcast_subnet->myip,
                    orig_broadcast_subnet->mask_ip ) )
      {
        DEBUG( 5, ( "wins_proxy_name_query_request_success: name %s is a WINS \
proxy name and is also on the same subnet (%s) as the requestor. \
Not replying.\n",
                    nmb_namestr(&namerec->name),
                    orig_broadcast_subnet->subnet_name ) );
        return;
      }
    }
  }

  /* Finally reply to the original name query. */
  reply_netbios_packet(original_packet,                /* Packet to reply to. */
                       0,                              /* Result code. */
                       NMB_QUERY,                      /* nmbd type code. */
                       NMB_NAME_QUERY_OPCODE,          /* opcode. */
                       ttl,                            /* ttl. */
                       rrec->rdata,                    /* data to send. */
                       rrec->rdlength);                /* data length. */
}

/****************************************************************************
Function called when the name lookup failed.
****************************************************************************/

static void wins_proxy_name_query_request_fail(struct subnet_record *subrec,
                                    struct response_record *rrec,
                                    struct nmb_name *question_name, int fail_code)
{
  DEBUG(4,("wins_proxy_name_query_request_fail: WINS server returned error code %d for lookup \
of name %s.\n", fail_code, nmb_namestr(question_name) ));
}

/****************************************************************************
Function to make a deep copy of the userdata we will need when the WINS
proxy query returns.
****************************************************************************/

static struct userdata_struct *wins_proxy_userdata_copy_fn(struct userdata_struct *userdata)
{
  struct packet_struct *p, *copy_of_p;
  struct userdata_struct *new_userdata = 
        (struct userdata_struct *)malloc( userdata->userdata_len );

  if(new_userdata == NULL)
    return NULL;

  new_userdata->copy_fn = userdata->copy_fn;
  new_userdata->free_fn = userdata->free_fn;
  new_userdata->userdata_len = userdata->userdata_len;

  /* Copy the subnet_record pointer. */
  memcpy( new_userdata->data, userdata->data, sizeof(struct subnet_record *) );

  /* Extract the pointer to the packet struct */
  memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
         sizeof(struct packet_struct *) );

  /* Do a deep copy of the packet. */
  if((copy_of_p = copy_packet(p)) == NULL)
  {
    SAFE_FREE(new_userdata);
    return NULL;
  }

  /* Lock the copy. */
  copy_of_p->locked = True;

  memcpy( &new_userdata->data[sizeof(struct subnet_record *)], (char *)&copy_of_p,
          sizeof(struct packet_struct *) );

  return new_userdata;
}

/****************************************************************************
Function to free the deep copy of the userdata we used when the WINS
proxy query returned.
****************************************************************************/

static void wins_proxy_userdata_free_fn(struct userdata_struct *userdata)
{
  struct packet_struct *p;

  /* Extract the pointer to the packet struct */
  memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
         sizeof(struct packet_struct *));

  /* Unlock the packet. */
  p->locked = False;

  free_packet(p);
  ZERO_STRUCTP(userdata);
  SAFE_FREE(userdata);
}

/****************************************************************************
 Make a WINS query on behalf of a broadcast client name query request.
****************************************************************************/

void make_wins_proxy_name_query_request( struct subnet_record *subrec, 
                                         struct packet_struct *incoming_packet,
                                         struct nmb_name *question_name)
{
  long *ud[(sizeof(struct userdata_struct) + sizeof(struct subrec *) + 
          sizeof(struct packet_struct *))/sizeof(long *) + 1];
  struct userdata_struct *userdata = (struct userdata_struct *)ud;

  memset(ud, '\0', sizeof(ud));
 
  userdata->copy_fn = wins_proxy_userdata_copy_fn;
  userdata->free_fn = wins_proxy_userdata_free_fn;
  userdata->userdata_len = sizeof(ud);
  memcpy( userdata->data, (char *)&subrec, sizeof(struct subnet_record *));
  memcpy( &userdata->data[sizeof(struct subnet_record *)], (char *)&incoming_packet,
          sizeof(struct packet_struct *));

  /* Now use the unicast subnet to query the name with the WINS server. */
  query_name( unicast_subnet, question_name->name, question_name->name_type,
              wins_proxy_name_query_request_success,
              wins_proxy_name_query_request_fail,
              userdata);
}