/*
 *  Paglo Crawler
 *  Copyright (C) 2006-2008 Paglo Labs Inc. All rights reserved.
 *  www.paglo.com
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of version 2 of the GNU General Public License as
 *  published by the Free Software Foundation.
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
//---------------------------------------------------------------------------
#include "ScanARPQuery.h"
#include "SniffThread.h"
#include "ScanThread.h"
#include "ScanAgentUtils.h"
#include "Debug.h"
//---------------------------------------------------------------------------

string TScanARPQuery::Description()
{
  return "Resolving MAC address for " + TargetIP.Print();
}
//---------------------------------------------------------------------------

TScanResult *TScanARPQuery::PerformScan(TPThread *Thread)
{
  TPacket *Pkt = NULL;
  TPacketQueue PktQueue;
  TARPHeader ArpFrm, *ArpPtr = NULL;
  TMacAddress TargetMac, SrcMac;

  /*
   * Only process ARP frames if they are for devices on the 
   * same logical subnet as we are. This will prevent us
   * from getting fooled by proxy ARP.
   */
  TIPAddress LocalNet(_GlobalConfig.GetInterfaceNetwork());
  TIPAddress LocalMask(_GlobalConfig.GetInterfaceNetmask());
  TCIDRBlock LocalBlock(LocalNet, LocalMask);
  
  if (LocalBlock.Includes(TargetIP)) {
        

    DEBUG_MESSAGE(DEBUG_SCANTHREAD, ("Sending ARP request to %s to determine MAC address.",
      TargetIP.Print().c_str()));

    /*
     * Construct an ARP packet.
     */
    memset(&ArpFrm, 0x00, sizeof(ArpFrm));
    memset(&ArpFrm.EthDest, 0xFF, 6);
    SrcMac = _GlobalConfig.GetInterface()->GetMacAddress();
    memcpy(&ArpFrm.EthSource, SrcMac.Value(), 6);
    ArpFrm.EthProto = htons(0x0806);
    ArpFrm.ARPHardwareType = htons(1);
    ArpFrm.ARPProtocolType = htons(0x0800);
    ArpFrm.ARPHardwareAddressLength = 6;
    ArpFrm.ARPProtocolAddressLength = 4;
    ArpFrm.ARPOpcode = htons(1);
    memcpy(ArpFrm.ARPSourceHW, ArpFrm.EthSource, 6);
    ArpFrm.ARPSourceProto = htonl(_GlobalConfig.GetInterfaceIPAddress().IPv4Value());
    ArpFrm.ARPTargetProto = htonl(TargetIP.IPv4Value());

    /*
     * Register PktQueue with the global SniffThread
     * so that we can get the ARP reply here.
     */
    _SniffThread->RegisterQueue(&PktQueue);

    /*
     * Send the ARP packet and wait for the reply.
     */
    SendRawFrame((unsigned char *)&ArpFrm, sizeof(ArpFrm));

    /*
     * Wait for replies.
     */
    /* TODO: This should be configurable. */
    MillisecondSleep(500);

    /*
     * De-Register the PacketQueue and start looking through the sniffed packets
     * for an response to the ARP request we sent.
     */
    _SniffThread->DeRegisterQueue(&PktQueue);
    while ((Pkt =  PktQueue.Get())) {

      ArpPtr = (TARPHeader *)Pkt->GetData();
      if (ArpPtr->EthProto == htons(0x0806) && ArpPtr->ARPOpcode == htons(2)) {
      
        DEBUG_MESSAGE(DEBUG_SCANTHREAD, ("ArpQuery: found an ARP reply!"));
      
        if (ArpPtr->ARPSourceProto == htonl(TargetIP.IPv4Value())) {

          TargetMac = TMacAddress(ArpPtr->ARPSourceHW);
          DEBUG_MESSAGE(DEBUG_SCANTHREAD, ("ArpQuery: %s is at %s",
            TargetIP.Print().c_str(), TargetMac.Print().c_str()));
        }
      }

      delete Pkt;
    }
  
    if (TargetMac.Valid()) {
      return new TScanResult(TargetMac, TargetIP);
    }    
  }

  return new TScanResult(TargetIP);     // RESULT_NONE
}
//---------------------------------------------------------------------------