init

vendor/github.com/anacrolix/torrent/peer_protocol/compactip.go

@@ -0,0 +1,22 @@
+package peer_protocol
+
+import (
+	"net"
+
+	"github.com/anacrolix/torrent/bencode"
+)
+
+// Marshals to the smallest compact byte representation.
+type CompactIp net.IP
+
+var _ bencode.Marshaler = CompactIp{}
+
+func (me CompactIp) MarshalBencode() ([]byte, error) {
+	return bencode.Marshal(func() []byte {
+		if ip4 := net.IP(me).To4(); ip4 != nil {
+			return ip4
+		} else {
+			return me
+		}
+	}())
+}

vendor/github.com/anacrolix/torrent/peer_protocol/decoder.go

@@ -0,0 +1,124 @@
+package peer_protocol
+
+import (
+	"bufio"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"sync"
+
+	"github.com/pkg/errors"
+)
+
+type Decoder struct {
+	R         *bufio.Reader
+	Pool      *sync.Pool
+	MaxLength Integer // TODO: Should this include the length header or not?
+}
+
+// io.EOF is returned if the source terminates cleanly on a message boundary.
+// TODO: Is that before or after the message?
+func (d *Decoder) Decode(msg *Message) (err error) {
+	var length Integer
+	err = binary.Read(d.R, binary.BigEndian, &length)
+	if err != nil {
+		if err != io.EOF {
+			err = fmt.Errorf("error reading message length: %s", err)
+		}
+		return
+	}
+	if length > d.MaxLength {
+		return errors.New("message too long")
+	}
+	if length == 0 {
+		msg.Keepalive = true
+		return
+	}
+	msg.Keepalive = false
+	r := &io.LimitedReader{R: d.R, N: int64(length)}
+	// Check that all of r was utilized.
+	defer func() {
+		if err != nil {
+			return
+		}
+		if r.N != 0 {
+			err = fmt.Errorf("%d bytes unused in message type %d", r.N, msg.Type)
+		}
+	}()
+	msg.Keepalive = false
+	c, err := readByte(r)
+	if err != nil {
+		return
+	}
+	msg.Type = MessageType(c)
+	switch msg.Type {
+	case Choke, Unchoke, Interested, NotInterested, HaveAll, HaveNone:
+		return
+	case Have, AllowedFast, Suggest:
+		err = msg.Index.Read(r)
+	case Request, Cancel, Reject:
+		for _, data := range []*Integer{&msg.Index, &msg.Begin, &msg.Length} {
+			err = data.Read(r)
+			if err != nil {
+				break
+			}
+		}
+	case Bitfield:
+		b := make([]byte, length-1)
+		_, err = io.ReadFull(r, b)
+		msg.Bitfield = unmarshalBitfield(b)
+	case Piece:
+		for _, pi := range []*Integer{&msg.Index, &msg.Begin} {
+			err := pi.Read(r)
+			if err != nil {
+				return err
+			}
+		}
+		dataLen := r.N
+		msg.Piece = (*d.Pool.Get().(*[]byte))
+		if int64(cap(msg.Piece)) < dataLen {
+			return errors.New("piece data longer than expected")
+		}
+		msg.Piece = msg.Piece[:dataLen]
+		_, err := io.ReadFull(r, msg.Piece)
+		if err != nil {
+			return errors.Wrap(err, "reading piece data")
+		}
+	case Extended:
+		b, err := readByte(r)
+		if err != nil {
+			break
+		}
+		msg.ExtendedID = ExtensionNumber(b)
+		msg.ExtendedPayload, err = ioutil.ReadAll(r)
+	case Port:
+		err = binary.Read(r, binary.BigEndian, &msg.Port)
+	default:
+		err = fmt.Errorf("unknown message type %#v", c)
+	}
+	return
+}
+
+func readByte(r io.Reader) (b byte, err error) {
+	var arr [1]byte
+	n, err := r.Read(arr[:])
+	b = arr[0]
+	if n == 1 {
+		err = nil
+		return
+	}
+	if err == nil {
+		panic(err)
+	}
+	return
+}
+
+func unmarshalBitfield(b []byte) (bf []bool) {
+	for _, c := range b {
+		for i := 7; i >= 0; i-- {
+			bf = append(bf, (c>>uint(i))&1 == 1)
+		}
+	}
+	return
+}

vendor/github.com/anacrolix/torrent/peer_protocol/extended.go

@@ -0,0 +1,32 @@
+package peer_protocol
+
+import "net"
+
+// http://www.bittorrent.org/beps/bep_0010.html
+type (
+	ExtendedHandshakeMessage struct {
+		M          map[ExtensionName]ExtensionNumber `bencode:"m"`
+		V          string                            `bencode:"v,omitempty"`
+		Reqq       int                               `bencode:"reqq,omitempty"`
+		Encryption bool                              `bencode:"e,omitempty"`
+		// BEP 9
+		MetadataSize int `bencode:"metadata_size,omitempty"`
+		// The local client port. It would be redundant for the receiving side of
+		// a connection to send this.
+		Port   int       `bencode:"p,omitempty"`
+		YourIp CompactIp `bencode:"yourip,omitempty"`
+		Ipv4   CompactIp `bencode:"ipv4,omitempty"`
+		Ipv6   net.IP    `bencode:"ipv6,omitempty"`
+	}
+
+	ExtensionName   string
+	ExtensionNumber int
+)
+
+const (
+	// http://www.bittorrent.org/beps/bep_0011.html
+	ExtensionNamePex ExtensionName = "ut_pex"
+	// http://bittorrent.org/beps/bep_0009.html. Note that there's an
+	// LT_metadata, but I've never implemented it.
+	ExtensionNameMetadata = "ut_metadata"
+)

vendor/github.com/anacrolix/torrent/peer_protocol/handshake.go

@@ -0,0 +1,138 @@
+package peer_protocol
+
+import (
+	"encoding/hex"
+	"fmt"
+	"io"
+
+	"github.com/anacrolix/missinggo"
+
+	"github.com/anacrolix/torrent/metainfo"
+)
+
+type ExtensionBit uint
+
+const (
+	ExtensionBitDHT      = 0  // http://www.bittorrent.org/beps/bep_0005.html
+	ExtensionBitExtended = 20 // http://www.bittorrent.org/beps/bep_0010.html
+	ExtensionBitFast     = 2  // http://www.bittorrent.org/beps/bep_0006.html
+)
+
+func handshakeWriter(w io.Writer, bb <-chan []byte, done chan<- error) {
+	var err error
+	for b := range bb {
+		_, err = w.Write(b)
+		if err != nil {
+			break
+		}
+	}
+	done <- err
+}
+
+type (
+	PeerExtensionBits [8]byte
+)
+
+func (me PeerExtensionBits) String() string {
+	return hex.EncodeToString(me[:])
+}
+
+func NewPeerExtensionBytes(bits ...ExtensionBit) (ret PeerExtensionBits) {
+	for _, b := range bits {
+		ret.SetBit(b)
+	}
+	return
+}
+
+func (pex PeerExtensionBits) SupportsExtended() bool {
+	return pex.GetBit(ExtensionBitExtended)
+}
+
+func (pex PeerExtensionBits) SupportsDHT() bool {
+	return pex.GetBit(ExtensionBitDHT)
+}
+
+func (pex PeerExtensionBits) SupportsFast() bool {
+	return pex.GetBit(ExtensionBitFast)
+}
+
+func (pex *PeerExtensionBits) SetBit(bit ExtensionBit) {
+	pex[7-bit/8] |= 1 << (bit % 8)
+}
+
+func (pex PeerExtensionBits) GetBit(bit ExtensionBit) bool {
+	return pex[7-bit/8]&(1<<(bit%8)) != 0
+}
+
+type HandshakeResult struct {
+	PeerExtensionBits
+	PeerID [20]byte
+	metainfo.Hash
+}
+
+// ih is nil if we expect the peer to declare the InfoHash, such as when the
+// peer initiated the connection. Returns ok if the Handshake was successful,
+// and err if there was an unexpected condition other than the peer simply
+// abandoning the Handshake.
+func Handshake(sock io.ReadWriter, ih *metainfo.Hash, peerID [20]byte, extensions PeerExtensionBits) (res HandshakeResult, ok bool, err error) {
+	// Bytes to be sent to the peer. Should never block the sender.
+	postCh := make(chan []byte, 4)
+	// A single error value sent when the writer completes.
+	writeDone := make(chan error, 1)
+	// Performs writes to the socket and ensures posts don't block.
+	go handshakeWriter(sock, postCh, writeDone)
+
+	defer func() {
+		close(postCh) // Done writing.
+		if !ok {
+			return
+		}
+		if err != nil {
+			panic(err)
+		}
+		// Wait until writes complete before returning from handshake.
+		err = <-writeDone
+		if err != nil {
+			err = fmt.Errorf("error writing: %s", err)
+		}
+	}()
+
+	post := func(bb []byte) {
+		select {
+		case postCh <- bb:
+		default:
+			panic("mustn't block while posting")
+		}
+	}
+
+	post([]byte(Protocol))
+	post(extensions[:])
+	if ih != nil { // We already know what we want.
+		post(ih[:])
+		post(peerID[:])
+	}
+	var b [68]byte
+	_, err = io.ReadFull(sock, b[:68])
+	if err != nil {
+		err = nil
+		return
+	}
+	if string(b[:20]) != Protocol {
+		return
+	}
+	missinggo.CopyExact(&res.PeerExtensionBits, b[20:28])
+	missinggo.CopyExact(&res.Hash, b[28:48])
+	missinggo.CopyExact(&res.PeerID, b[48:68])
+	// peerExtensions.Add(res.PeerExtensionBits.String(), 1) 
+
+	// TODO: Maybe we can just drop peers here if we're not interested. This
+	// could prevent them trying to reconnect, falsely believing there was
+	// just a problem.
+	if ih == nil { // We were waiting for the peer to tell us what they wanted.
+		post(res.Hash[:])
+		post(peerID[:])
+	}
+
+	ok = true
+	return
+}

vendor/github.com/anacrolix/torrent/peer_protocol/int.go

@@ -0,0 +1,25 @@
+package peer_protocol
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+type Integer uint32
+
+func (i *Integer) Read(r io.Reader) error {
+	return binary.Read(r, binary.BigEndian, i)
+}
+
+// It's perfectly fine to cast these to an int. TODO: Or is it?
+func (i Integer) Int() int {
+	return int(i)
+}
+
+func (i Integer) Uint64() uint64 {
+	return uint64(i)
+}
+
+func (i Integer) Uint32() uint32 {
+	return uint32(i)
+}

vendor/github.com/anacrolix/torrent/peer_protocol/messagetype_string.go

@@ -0,0 +1,30 @@
+// Code generated by "stringer -type=MessageType"; DO NOT EDIT.
+
+package peer_protocol
+
+import "strconv"
+
+const (
+	_MessageType_name_0 = "ChokeUnchokeInterestedNotInterestedHaveBitfieldRequestPieceCancelPort"
+	_MessageType_name_1 = "SuggestHaveAllHaveNoneRejectAllowedFast"
+	_MessageType_name_2 = "Extended"
+)
+
+var (
+	_MessageType_index_0 = [...]uint8{0, 5, 12, 22, 35, 39, 47, 54, 59, 65, 69}
+	_MessageType_index_1 = [...]uint8{0, 7, 14, 22, 28, 39}
+)
+
+func (i MessageType) String() string {
+	switch {
+	case 0 <= i && i <= 9:
+		return _MessageType_name_0[_MessageType_index_0[i]:_MessageType_index_0[i+1]]
+	case 13 <= i && i <= 17:
+		i -= 13
+		return _MessageType_name_1[_MessageType_index_1[i]:_MessageType_index_1[i+1]]
+	case i == 20:
+		return _MessageType_name_2
+	default:
+		return "MessageType(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+}

vendor/github.com/anacrolix/torrent/peer_protocol/msg.go

@@ -0,0 +1,116 @@
+package peer_protocol
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+)
+
+type Message struct {
+	Keepalive            bool
+	Type                 MessageType
+	Index, Begin, Length Integer
+	Piece                []byte
+	Bitfield             []bool
+	ExtendedID           ExtensionNumber
+	ExtendedPayload      []byte
+	Port                 uint16
+}
+
+func MakeCancelMessage(piece, offset, length Integer) Message {
+	return Message{
+		Type:   Cancel,
+		Index:  piece,
+		Begin:  offset,
+		Length: length,
+	}
+}
+
+func (msg Message) RequestSpec() (ret RequestSpec) {
+	return RequestSpec{
+		msg.Index,
+		msg.Begin,
+		func() Integer {
+			if msg.Type == Piece {
+				return Integer(len(msg.Piece))
+			} else {
+				return msg.Length
+			}
+		}(),
+	}
+}
+
+func (msg Message) MustMarshalBinary() []byte {
+	b, err := msg.MarshalBinary()
+	if err != nil {
+		panic(err)
+	}
+	return b
+}
+
+func (msg Message) MarshalBinary() (data []byte, err error) {
+	buf := &bytes.Buffer{}
+	if !msg.Keepalive {
+		err = buf.WriteByte(byte(msg.Type))
+		if err != nil {
+			return
+		}
+		switch msg.Type {
+		case Choke, Unchoke, Interested, NotInterested, HaveAll, HaveNone:
+		case Have:
+			err = binary.Write(buf, binary.BigEndian, msg.Index)
+		case Request, Cancel, Reject:
+			for _, i := range []Integer{msg.Index, msg.Begin, msg.Length} {
+				err = binary.Write(buf, binary.BigEndian, i)
+				if err != nil {
+					break
+				}
+			}
+		case Bitfield:
+			_, err = buf.Write(marshalBitfield(msg.Bitfield))
+		case Piece:
+			for _, i := range []Integer{msg.Index, msg.Begin} {
+				err = binary.Write(buf, binary.BigEndian, i)
+				if err != nil {
+					return
+				}
+			}
+			n, err := buf.Write(msg.Piece)
+			if err != nil {
+				break
+			}
+			if n != len(msg.Piece) {
+				panic(n)
+			}
+		case Extended:
+			err = buf.WriteByte(byte(msg.ExtendedID))
+			if err != nil {
+				return
+			}
+			_, err = buf.Write(msg.ExtendedPayload)
+		case Port:
+			err = binary.Write(buf, binary.BigEndian, msg.Port)
+		default:
+			err = fmt.Errorf("unknown message type: %v", msg.Type)
+		}
+	}
+	data = make([]byte, 4+buf.Len())
+	binary.BigEndian.PutUint32(data, uint32(buf.Len()))
+	if buf.Len() != copy(data[4:], buf.Bytes()) {
+		panic("bad copy")
+	}
+	return
+}
+
+func marshalBitfield(bf []bool) (b []byte) {
+	b = make([]byte, (len(bf)+7)/8)
+	for i, have := range bf {
+		if !have {
+			continue
+		}
+		c := b[i/8]
+		c |= 1 << uint(7-i%8)
+		b[i/8] = c
+	}
+	return
+}

vendor/github.com/anacrolix/torrent/peer_protocol/pex.go

@@ -0,0 +1,26 @@
+package peer_protocol
+
+import "github.com/anacrolix/dht/krpc"
+
+type PexMsg struct {
+	Added       krpc.CompactIPv4NodeAddrs `bencode:"added"`
+	AddedFlags  []PexPeerFlags            `bencode:"added.f"`
+	Added6      krpc.CompactIPv6NodeAddrs `bencode:"added6"`
+	Added6Flags []PexPeerFlags            `bencode:"added6.f"`
+	Dropped     krpc.CompactIPv4NodeAddrs `bencode:"dropped"`
+	Dropped6    krpc.CompactIPv6NodeAddrs `bencode:"dropped6"`
+}
+
+type PexPeerFlags byte
+
+func (me PexPeerFlags) Get(f PexPeerFlags) bool {
+	return me&f == f
+}
+
+const (
+	PexPrefersEncryption = 0x01
+	PexSeedUploadOnly    = 0x02
+	PexSupportsUtp       = 0x04
+	PexHolepunchSupport  = 0x08
+	PexOutgoingConn      = 0x10
+)

vendor/github.com/anacrolix/torrent/peer_protocol/protocol.go

@@ -0,0 +1,45 @@
+package peer_protocol
+
+const (
+	Protocol = "\x13BitTorrent protocol"
+)
+
+type MessageType byte
+
+//go:generate stringer -type=MessageType
+
+func (mt MessageType) FastExtension() bool {
+	return mt >= Suggest && mt <= AllowedFast
+}
+
+const (
+	// BEP 3
+	Choke         MessageType = 0
+	Unchoke       MessageType = 1
+	Interested    MessageType = 2
+	NotInterested MessageType = 3
+	Have          MessageType = 4
+	Bitfield      MessageType = 5
+	Request       MessageType = 6
+	Piece         MessageType = 7
+	Cancel        MessageType = 8
+	Port          MessageType = 9
+
+	// BEP 6 - Fast extension
+	Suggest     MessageType = 0x0d // 13
+	HaveAll     MessageType = 0x0e // 14
+	HaveNone    MessageType = 0x0f // 15
+	Reject      MessageType = 0x10 // 16
+	AllowedFast MessageType = 0x11 // 17
+
+	// BEP 10
+	Extended MessageType = 20
+)
+
+const (
+	HandshakeExtendedID = 0
+
+	RequestMetadataExtensionMsgType = 0
+	DataMetadataExtensionMsgType    = 1
+	RejectMetadataExtensionMsgType  = 2
+)

vendor/github.com/anacrolix/torrent/peer_protocol/reqspec.go

@@ -0,0 +1,11 @@
+package peer_protocol
+
+import "fmt"
+
+type RequestSpec struct {
+	Index, Begin, Length Integer
+}
+
+func (me RequestSpec) String() string {
+	return fmt.Sprintf("{%d %d %d}", me.Index, me.Begin, me.Length)
+}