forked from moretti/gotorrent
/
peer.go
186 lines (159 loc) · 4.75 KB
/
peer.go
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package gotorrent
import (
"bytes"
log "code.google.com/p/tcgl/applog"
"encoding/binary"
"github.com/moretti/gotorrent/bitarray"
"github.com/moretti/gotorrent/messages"
"io"
"net"
"time"
)
type Peer struct {
Addr net.TCPAddr
Conn net.Conn
Data []byte
BitField *bitarray.BitArray
PieceCount uint32
PieceLength uint32
//Handshake bool
//Interested bool
//Choked bool
}
func (peer *Peer) Connect() (err error) {
log.Debugf("Connecting to %s...", peer.Addr.String())
peer.Conn, err = net.DialTimeout("tcp", peer.Addr.String(), time.Second*5)
if peer.Conn == nil || err != nil {
log.Debugf("Unable to connect to %s", peer.Addr.String())
}
log.Debugf("Connected to %s", peer.Addr.String())
return
}
func (peer *Peer) SendUnchoke() (err error) {
unchoke := messages.NewUnchoke()
err = binary.Write(peer.Conn, binary.BigEndian, unchoke)
return
}
func (peer *Peer) SendInterested() (err error) {
interested := messages.NewInterested()
err = binary.Write(peer.Conn, binary.BigEndian, interested)
return
}
func (peer *Peer) SendHandshake(infoHash, peerId string) (err error) {
hand := messages.NewHandshake(infoHash, peerId)
err = binary.Write(peer.Conn, binary.BigEndian, hand)
return
}
func (peer *Peer) ReadHandshake() (err error) {
buf := make([]byte, messages.HandshakeLength)
n, err := peer.Conn.Read(buf)
if err != nil || n != messages.HandshakeLength {
log.Errorf("Cannot read the handshake: %v", err)
return err
}
var hand messages.Handshake
err = binary.Read(bytes.NewBuffer(buf), binary.BigEndian, &hand)
if err != nil {
log.Errorf("%v", err)
}
log.Debugf("Handshake from peer %v", peer.Addr.String())
log.Debugf(hand.String())
return err
}
func (peer *Peer) RequestBlock(pieceIndex, blockOffset, blockLenght uint32) (err error) {
req := messages.NewRequest(pieceIndex, blockOffset, blockLenght)
err = binary.Write(peer.Conn, binary.BigEndian, req)
return
}
func (peer *Peer) ReceiveData() (err error) {
nBytes := 0
buf := make([]byte, 65536)
for {
peer.Conn.SetReadDeadline(time.Now().Add(5 * time.Second))
n, err := peer.Conn.Read(buf)
readed := buf[:n]
nBytes += n
if err == io.EOF || n == 0 {
break
}
if err != nil {
log.Errorf("Error in reading: %v", err)
return err
}
peer.Data = append(peer.Data, readed...)
}
log.Debugf("Readed %v, byte(s)", nBytes)
//log.Debugf("%v", peer.Data)
return
}
func (peer *Peer) ParseData() {
for {
if len(peer.Data) < 4 {
break
/*peer.SendUnchoke()
peer.SendInterested()
log.Debugf("Trying to request piece #%v", i)
peer.RequestBlock(300, 0, uint32(PieceChunkLenght))
peer.ReceiveData()
i++*/
}
var message messages.Message
err := binary.Read(bytes.NewBuffer(peer.Data[:4]), binary.BigEndian, &message.Length)
if err != nil {
panic(err)
}
if message.Length == 0 {
log.Debugf("Keep alive")
peer.Data = peer.Data[4:]
} else {
message.Id = peer.Data[4]
data := peer.Data[:4+message.Length]
switch message.Id {
case messages.ChokeId:
log.Debugf("Choke")
case messages.UnchokeId:
log.Debugf("Unchoke")
case messages.InterestedId:
log.Debugf("Interested")
case messages.NotInterestedId:
log.Debugf("NotInterested")
case messages.HaveId:
var haveMsg messages.Have
err = binary.Read(bytes.NewBuffer(data), binary.BigEndian, &haveMsg)
log.Debugf("Peer %v - Have piece #%v", peer.Addr.String(), haveMsg.PieceIndex)
if haveMsg.PieceIndex > peer.PieceCount {
log.Errorf("Invalid piece index, piece index: %v, piece count: %v", haveMsg.PieceIndex, peer.PieceCount)
break
}
peer.BitField.Set(int(haveMsg.PieceIndex), true)
log.Debugf("Peer %v - BitField updated", peer.Addr.String())
case messages.BitFieldId:
log.Debugf("BitField")
var bitMsg messages.BitArray
err = binary.Read(bytes.NewBuffer(data), binary.BigEndian, &bitMsg)
bitMsg.BitField = data[:message.Length-1]
bitCount := (message.Length - 1) * 8
if peer.PieceCount > bitCount {
log.Errorf("Invalid BitField, bit count: %v, piece count: %v", bitCount, peer.PieceCount)
break
}
peer.BitField = bitarray.NewFromBytes(bitMsg.BitField, int(peer.PieceCount))
log.Debugf("Peer %v - New BitField:", peer.Addr.String())
case messages.RequestId:
log.Debugf("Request")
case messages.PieceId:
log.Debugf("Piece")
var pieceMsg messages.Piece
err = binary.Read(bytes.NewBuffer(data), binary.BigEndian, &pieceMsg)
pieceMsg.BlockData = data[:message.Length - 9]
log.Debugf("Peer %v - Found a new block - PieceIndex: %v BlockOffset: %v", peer.Addr.String(), pieceMsg.PieceIndex, pieceMsg.BlockOffset)
case messages.CancelId:
log.Debugf("Cancel")
case messages.PortId:
log.Debugf("Port")
}
peer.Data = peer.Data[4+message.Length:]
}
}
return
}