BTTrackerRequest.cpp

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//
// BTTrackerRequest.cpp
//
// Copyright (c) Shareaza Development Team, 2002-2005.
// This file is part of SHAREAZA (www.shareaza.com)
//
// Shareaza 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.
//
// Shareaza 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 Shareaza; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//

#include "StdAfx.h"
#include "Shareaza.h"
#include "Settings.h"
#include "Network.h"
#include "BENode.h"
#include "BTClients.h"
#include "BTTrackerRequest.h"
#include "Transfers.h"
#include "Downloads.h"
#include "Download.h"
#include "SHA.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

BEGIN_MESSAGE_MAP(CBTTrackerRequest, CWinThread)
        //{{AFX_MSG_MAP(CBTTrackerRequest)
        //}}AFX_MSG_MAP
END_MESSAGE_MAP()


// CBTTrackerRequest construction

CBTTrackerRequest::CBTTrackerRequest(CDownload* pDownload, LPCTSTR pszVerb, BOOL bProcess, WORD nNumWant)
{
        ASSERT( pDownload != NULL );
        ASSERT( pDownload->m_pTorrent.IsAvailable() ); 
        
        m_bAutoDelete   = TRUE;
        m_pDownload             = pDownload;
        m_bProcess              = bProcess;
        
        CString strURL;
        // Create the basic URL
        strURL.Format( _T("%s?info_hash=%s&peer_id=%s&port=%i&uploaded=%I64i&downloaded=%I64i&left=%I64i&compact=1"),
                (LPCTSTR)pDownload->m_pTorrent.m_sTracker,
                (LPCTSTR)Escape( &pDownload->m_pBTH ),
                (LPCTSTR)Escape( &m_pDownload->m_pPeerID ),
                Network.m_pHost.sin_port ? (int)htons( Network.m_pHost.sin_port ) : (int)Settings.Connection.InPort,
                (QWORD)pDownload->m_nTorrentUploaded,
                (QWORD)pDownload->m_nTorrentDownloaded,
                (QWORD)pDownload->GetVolumeRemaining() );
        
        // If the IP is valid, add it.
        if ( Network.m_pHost.sin_addr.S_un.S_addr != 0 )
        {       
                strURL += _T("&ip=");
                strURL += inet_ntoa( Network.m_pHost.sin_addr );
                // Note: Some trackers ignore this value and take the IP the request came from. (Usually the same)
        }
        
        // If an event was specified, add it.
        if ( pszVerb != NULL )
        {       
                strURL += _T("&event=");
                strURL += pszVerb;
                // Valid events: started, completed, stopped
        }

        // If a (valid) number of peers was specified, request that many.
        if ( nNumWant < 300 )
        {       
                CString strNumWant;
                strNumWant.Format( _T("&numwant=%i"), nNumWant );
                strURL += strNumWant;
                // Note: If this is omitted, trackers usually respond with 50, which is a good default.
                // Generally, it's not worth the bandwidth to send this. However, if we have plenty of 
                // sources, then ask for a lower number. (EG 5, just to ensure some sources are fresh)
        }       

        // If the TrackerKey is true and we have a valid key, then use it.
        if ( ( pDownload->m_sKey.GetLength() > 4 ) && ( Settings.BitTorrent.TrackerKey ) )
        {       
                ASSERT ( pDownload->m_sKey.GetLength() < 20 );          //Key too long

                strURL += _T("&key=");
                strURL += pDownload->m_sKey;
        }       
        
        m_pRequest.SetURL( strURL );
        //m_pRequest.AddHeader( _T("Accept"), _T("application/x-bittorrent") ); // This causes problems with some trackers
        m_pRequest.AddHeader( _T("Accept-Encoding"), _T("gzip") );
        
        if ( Settings.BitTorrent.StandardPeerID )
        {
                CString strUserAgent = Settings.SmartAgent();
                m_pRequest.SetUserAgent( strUserAgent );
        }

        //m_pRequest.AddHeader( _T("Cache-Control"), _T("no-cache") ); // Shouldn't be needed

        //theApp.Message( MSG_DEBUG, _T("Sending announce") );

        BTClients.Add( this );
        CreateThread();
}

CBTTrackerRequest::~CBTTrackerRequest()
{
        BTClients.Remove( this );
}

// CBTTrackerRequest actions

void CBTTrackerRequest::SendStarted(CDownloadBase* pDownload, WORD nNumWant)
{
        if ( ((CDownload*)pDownload)->m_pTorrent.m_sTracker.IsEmpty() ) return;
        new CBTTrackerRequest( (CDownload*)pDownload, _T("started"), TRUE, nNumWant );
}

void CBTTrackerRequest::SendUpdate(CDownloadBase* pDownload, WORD nNumWant)
{
        if ( ((CDownload*)pDownload)->m_pTorrent.m_sTracker.IsEmpty() ) return;
        new CBTTrackerRequest( (CDownload*)pDownload,  NULL , TRUE, nNumWant );
}

void CBTTrackerRequest::SendCompleted(CDownloadBase* pDownload)
{
        if ( ((CDownload*)pDownload)->m_pTorrent.m_sTracker.IsEmpty() ) return;
        new CBTTrackerRequest( (CDownload*)pDownload, _T("completed"), TRUE, 0 );
}

void CBTTrackerRequest::SendStopped(CDownloadBase* pDownload)
{
        if ( ((CDownload*)pDownload)->m_pTorrent.m_sTracker.IsEmpty() ) return;
        new CBTTrackerRequest( (CDownload*)pDownload, _T("stopped"), FALSE, 0xFFFF );
}

// CBTTrackerRequest escaper

CString CBTTrackerRequest::Escape(SHA1* pSHA1)
{
        static LPCTSTR pszHex = _T("0123456789ABCDEF");
        
        CString str;
        LPTSTR psz = str.GetBuffer( sizeof(SHA1) * 3 + 1 );
        
        for ( int nByte = 0 ; nByte < sizeof(SHA1) ; nByte++ )
        {
                int nValue = (int)(unsigned char)pSHA1->n[ nByte ];
                
                if (    ( nValue >= '0' && nValue <= '9' ) ||
                                ( nValue >= 'a' && nValue <= 'z' ) ||
                                ( nValue >= 'A' && nValue <= 'Z' ) )
                {
                        *psz++ = (TCHAR)nValue;
                }
                else
                {
                        *psz++ = '%';
                        *psz++ = pszHex[ ( nValue >> 4 ) & 15 ];
                        *psz++ = pszHex[ nValue & 15 ];
                }
        }
        
        *psz = 0;
        str.ReleaseBuffer();
        
        return str;
}

// CBTTrackerRequest run

BOOL CBTTrackerRequest::InitInstance() 
{
        return TRUE;
}

int CBTTrackerRequest::Run() 
{       
        if ( m_bProcess )
        {
                Process( m_pRequest.Execute( FALSE ) );
        }
        else
        {
                m_pRequest.Execute( FALSE );
        }
        
        return 0;
}

void CBTTrackerRequest::Process(BOOL bRequest)
{
        CSingleLock pLock( &Transfers.m_pSection );
        
        if ( ! pLock.Lock( 250 ) ) return;
        if ( ! Downloads.Check( m_pDownload ) ) return;
        if ( ! m_pDownload->m_bTorrentRequested ) return;
        
        if ( ! bRequest )
        {
                m_pDownload->OnTrackerEvent( FALSE );
                return;
        }
        
        if ( ! m_pRequest.InflateResponse() )
        {
                theApp.Message( MSG_ERROR, IDS_BT_TRACK_PARSE_ERROR );
                return;
        }
        
        CBuffer* pBuffer = m_pRequest.GetResponseBuffer();
        if ( pBuffer == NULL ) return;

        CBENode* pRoot = CBENode::Decode( pBuffer );
        
        if ( pRoot->IsType( CBENode::beDict ) )
        {
                Process( pRoot );
        }
        else if ( pRoot->IsType( CBENode::beString ) )
        {
                CString str = pRoot->GetString();
                theApp.Message( MSG_ERROR, IDS_BT_TRACK_ERROR,
                        (LPCTSTR)m_pDownload->GetDisplayName(), (LPCTSTR)str );
                m_pDownload->OnTrackerEvent( FALSE, str );
        }
        else
        {
                theApp.Message( MSG_ERROR, IDS_BT_TRACK_PARSE_ERROR );
                m_pDownload->OnTrackerEvent( FALSE );
        }
        
        if ( pRoot != NULL ) delete pRoot;
}

BOOL CBTTrackerRequest::Process(CBENode* pRoot)
{
        CString strError;

        // Check for failure
        if ( CBENode* pError = pRoot->GetNode( "failure reason" ) )
        {
                strError = pError->GetString();
                theApp.Message( MSG_ERROR, IDS_BT_TRACK_ERROR,
                        (LPCTSTR)m_pDownload->GetDisplayName(), (LPCTSTR)strError );
                m_pDownload->OnTrackerEvent( FALSE, strError );
                return FALSE;
        }
        
        // Get the interval (next tracker contact)
        CBENode* pInterval = pRoot->GetNode( "interval" );
        if ( ! pInterval->IsType( CBENode::beInt ) ) 
        {
                LoadString( strError, IDS_BT_TRACK_PARSE_ERROR );
                m_pDownload->OnTrackerEvent( FALSE, strError );
                return FALSE;
        }
        int nInterval = (int)(DWORD)pInterval->GetInt();

        // Verify interval is valid
        nInterval = max( nInterval, 60*2 );
        nInterval = min( nInterval, 60*60 );
        
        m_pDownload->m_tTorrentTracker = GetTickCount() + 1000 * nInterval;
        m_pDownload->m_bTorrentStarted = TRUE;
        
        // Get list of peers
        CBENode* pPeers = pRoot->GetNode( "peers" );
        int nCount = 0;
        
        if ( pPeers->IsType( CBENode::beList )  && ( ( ! m_pDownload->IsMoving() ) || ( Settings.Connection.FirewallStatus == CONNECTION_FIREWALLED ) ) )
        {
                for ( int nPeer = 0 ; nPeer < pPeers->GetCount() ; nPeer++ )
                {
                        CBENode* pPeer = pPeers->GetNode( nPeer );
                        if ( ! pPeer->IsType( CBENode::beDict ) ) continue;
                        
                        CBENode* pID = pPeer->GetNode( "peer id" );
                        
                        CBENode* pIP = pPeer->GetNode( "ip" );
                        if ( ! pIP->IsType( CBENode::beString ) ) continue;
                        
                        CBENode* pPort = pPeer->GetNode( "port" );
                        if ( ! pPort->IsType( CBENode::beInt ) ) continue;
                        
                        SOCKADDR_IN saPeer;
                        if ( ! Network.Resolve( pIP->GetString(), (int)pPort->GetInt(), &saPeer ) ) continue;
                        
                        theApp.Message( MSG_DEBUG, _T("Tracker: %s:%i"),
                                (LPCTSTR)CString( inet_ntoa( saPeer.sin_addr ) ), htons( saPeer.sin_port ) );
                        
                        if ( pID->IsType( CBENode::beString ) && pID->m_nValue == sizeof(SHA1) )
                        {
                                nCount += m_pDownload->AddSourceBT( (SHA1*)pID->m_pValue,
                                        &saPeer.sin_addr, ntohs( saPeer.sin_port ) );
                        }
                        else
                        {
                                nCount += m_pDownload->AddSourceBT( NULL,
                                        &saPeer.sin_addr, ntohs( saPeer.sin_port ) );
                        }
                }
        }
        else if ( pPeers->IsType( CBENode::beString ) && ( ( ! m_pDownload->IsMoving() ) || ( Settings.Connection.FirewallStatus == CONNECTION_FIREWALLED  ) ) )
        {
                if ( 0 == ( pPeers->m_nValue % 6 ) )
                {
                        BYTE* pPointer = (BYTE*)pPeers->m_pValue;
                        
                        for ( int nPeer = (int)pPeers->m_nValue / 6 ; nPeer > 0 ; nPeer --, pPointer += 6 )
                        {
                                IN_ADDR* pAddress = (IN_ADDR*)pPointer;
                                WORD nPort = *(WORD*)( pPointer + 4 );
                                
                                nCount += m_pDownload->AddSourceBT( NULL, pAddress, ntohs( nPort ) );
                        }
                }
        }

        // Okay, clear any errors and continue
        m_pDownload->OnTrackerEvent( TRUE );

        theApp.Message( MSG_DEFAULT, IDS_BT_TRACK_SUCCESS,
                (LPCTSTR)m_pDownload->GetDisplayName(), nCount );       
        return TRUE;
}

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