/*
* Created on Apr 30, 2004
* Created by Alon Rohter
* Copyright (C) 2004, 2005, 2006 Aelitis, All Rights Reserved.
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* AELITIS, SAS au capital de 46,603.30 euros
* 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
*
*/
package com.aelitis.azureus.core.peermanager.messaging.bittorrent;
import org.gudy.azureus2.core3.util.*;
import com.aelitis.azureus.core.networkmanager.RawMessage;
import com.aelitis.azureus.core.peermanager.messaging.*;
import com.aelitis.azureus.core.peermanager.utils.PeerClassifier;
/**
* BitTorrent handshake message.
*/
public class BTHandshake implements BTMessage, RawMessage {
public static final String PROTOCOL = "BitTorrent protocol";
// No reserve bits set.
private static final byte[] BT_RESERVED = new byte[]{0, 0, 0, 0, 0, 0, 0, 0 };
// Set first bit of first byte to indicate advanced AZ messaging support. (128)
// Set fourth bit of fifth byte to indicate LT messaging support. (16)
// Set seventh bit (2) and eight bit (1) to force AZMP over LTEP. [current behaviour]
// Set seventh bit (2) only to prefer AZMP over LTEP.
// Set eighth bit (1) only to prefer LTEP over AZMP.
private static final byte[] AZ_RESERVED = new byte[]{(byte)128, 0, 0, 0, 0, (byte)19, 0, 0 };
public static void setMainlineDHTEnabled(boolean enabled) {
if (enabled) {
//BT_RESERVED[7] = (byte)(BT_RESERVED[7] | 0x01);
AZ_RESERVED[7] = (byte)(AZ_RESERVED[7] | 0x01);
}
else {
//BT_RESERVED[7] = (byte)(BT_RESERVED[7] & 0xFE);
AZ_RESERVED[7] = (byte)(AZ_RESERVED[7] & 0xFE);
}
}
public static final boolean FAST_EXTENSION_ENABLED = true;
public static void setFastExtensionEnabled(boolean enabled) {
if (enabled) {
//BT_RESERVED[7] = (byte)(BT_RESERVED[7] | 0x04);
AZ_RESERVED[7] = (byte)(AZ_RESERVED[7] | 0x04);
}
else {
//BT_RESERVED[7] = (byte)(BT_RESERVED[7] & 0xF3);
AZ_RESERVED[7] = (byte)(AZ_RESERVED[7] & 0xF3);
}
}
static{
setFastExtensionEnabled( FAST_EXTENSION_ENABLED );
}
private DirectByteBuffer buffer = null;
private String description = null;
private final byte[] reserved_bytes;
private final byte[] datahash_bytes;
private final byte[] peer_id_bytes;
private final byte version;
private static byte[] duplicate(byte[] b) {
byte[] r = new byte[b.length];
System.arraycopy(b, 0, r, 0, b.length);
return r;
}
/**
* Used for outgoing handshake message.
* @param data_hash
* @param peer_id
* @param set_reserve_bit
*/
public BTHandshake( byte[] data_hash, byte[] peer_id, boolean set_reserve_bit, byte version ) {
this( duplicate(set_reserve_bit ? AZ_RESERVED : BT_RESERVED), data_hash, peer_id, version );
}
private BTHandshake( byte[] reserved, byte[] data_hash, byte[] peer_id, byte version ) {
this.reserved_bytes = reserved;
this.datahash_bytes = data_hash;
this.peer_id_bytes = peer_id;
this.version = version;
}
private void constructBuffer() {
buffer = DirectByteBufferPool.getBuffer( DirectByteBuffer.AL_MSG_BT_HAND, 68 );
buffer.put( DirectByteBuffer.SS_MSG, (byte)PROTOCOL.length() );
buffer.put( DirectByteBuffer.SS_MSG, PROTOCOL.getBytes() );
buffer.put( DirectByteBuffer.SS_MSG, reserved_bytes );
buffer.put( DirectByteBuffer.SS_MSG, datahash_bytes );
buffer.put( DirectByteBuffer.SS_MSG, peer_id_bytes );
buffer.flip( DirectByteBuffer.SS_MSG );
}
public byte[] getReserved() { return reserved_bytes; }
public byte[] getDataHash() { return datahash_bytes; }
public byte[] getPeerId() { return peer_id_bytes; }
// message
public String getID() { return BTMessage.ID_BT_HANDSHAKE; }
public byte[] getIDBytes() { return BTMessage.ID_BT_HANDSHAKE_BYTES; }
public String getFeatureID() { return BTMessage.BT_FEATURE_ID; }
public int getFeatureSubID() { return BTMessage.SUBID_BT_HANDSHAKE; }
public int getType() { return Message.TYPE_PROTOCOL_PAYLOAD; }
public byte getVersion() { return version; };
public String getDescription() {
if( description == null ) {
description = BTMessage.ID_BT_HANDSHAKE + " of dataID: " +ByteFormatter.nicePrint( datahash_bytes, true ) + " peerID: " +PeerClassifier.getPrintablePeerID( peer_id_bytes );
}
return description;
}
public DirectByteBuffer[] getData() {
if( buffer == null ) {
constructBuffer();
}
return new DirectByteBuffer[]{ buffer };
}
public Message deserialize( DirectByteBuffer data, byte version ) throws MessageException {
if( data == null ) {
throw new MessageException( "[" +getID() + "] decode error: data == null" );
}
if( data.remaining( DirectByteBuffer.SS_MSG ) != 68 ) {
throw new MessageException( "[" +getID() + "] decode error: payload.remaining[" +data.remaining( DirectByteBuffer.SS_MSG )+ "] != 68" );
}
if( data.get( DirectByteBuffer.SS_MSG ) != (byte)PROTOCOL.length() ) {
throw new MessageException( "[" +getID() + "] decode error: payload.get() != (byte)PROTOCOL.length()" );
}
byte[] header = new byte[ PROTOCOL.getBytes().length ];
data.get( DirectByteBuffer.SS_MSG, header );
if( !PROTOCOL.equals( new String( header ) ) ) {
throw new MessageException( "[" +getID() + "] decode error: invalid protocol given: " + new String( header ) );
}
byte[] reserved = new byte[ 8 ];
data.get( DirectByteBuffer.SS_MSG, reserved );
byte[] infohash = new byte[ 20 ];
data.get( DirectByteBuffer.SS_MSG, infohash );
byte[] peerid = new byte[ 20 ];
data.get( DirectByteBuffer.SS_MSG, peerid );
data.returnToPool();
if ( peerid[0] == (byte)0 && peerid[1] == (byte)0){
boolean ok = false;
for (int i=2;i<20;i++){
if ( peerid[i] != (byte)0){
ok = true;
break;
}
}
if ( !ok ){
byte[] x = ("-" + "#@" + "0000" + "-").getBytes(); // bad peer id decode
RandomUtils.nextBytes( peerid );
System.arraycopy(x, 0, peerid, 0, x.length );
}
}
return new BTHandshake( reserved, infohash, peerid, version );
}
// raw message
public DirectByteBuffer[] getRawData() {
if( buffer == null ) {
constructBuffer();
}
return new DirectByteBuffer[]{ buffer };
}
public int getPriority() { return RawMessage.PRIORITY_HIGH; }
public boolean isNoDelay() { return true; }
public void
setNoDelay(){}
public Message[] messagesToRemove() { return null; }
public void destroy() {
if( buffer != null ) buffer.returnToPool();
}
public Message getBaseMessage() { return this; }
}