Merge pull request #12 from 9seconds/block-rwc

Refactoring for packet mode

client/client.go

@@ -8,5 +8,4 @@ import (
 	"github.com/9seconds/mtg/wrappers"
 )
 
-// Init has to initialize client connection based on given config.
-type Init func(net.Conn, *config.Config) (*mtproto.ConnectionOpts, wrappers.ReadWriteCloserWithAddr, error)
+type Init func(net.Conn, string, *config.Config) (wrappers.Wrap, *mtproto.ConnectionOpts, error)

client/direct.go

@@ -14,28 +14,29 @@ import (
 
 const handshakeTimeout = 10 * time.Second
 
-// DirectInit initializes client to access Telegram bypassing middleproxies.
-func DirectInit(conn net.Conn, conf *config.Config) (*mtproto.ConnectionOpts, wrappers.ReadWriteCloserWithAddr, error) {
-	if err := config.SetSocketOptions(conn); err != nil {
+func DirectInit(socket net.Conn, connID string, conf *config.Config) (wrappers.Wrap, *mtproto.ConnectionOpts, error) {
+	if err := config.SetSocketOptions(socket); err != nil {
 		return nil, nil, errors.Annotate(err, "Cannot set socket options")
 	}
 
-	conn.SetReadDeadline(time.Now().Add(handshakeTimeout)) // nolint: errcheck
-	frame, err := obfuscated2.ExtractFrame(conn)
-	conn.SetReadDeadline(time.Time{}) // nolint: errcheck
+	socket.SetReadDeadline(time.Now().Add(handshakeTimeout))
+	frame, err := obfuscated2.ExtractFrame(socket)
 	if err != nil {
 		return nil, nil, errors.Annotate(err, "Cannot extract frame")
 	}
+	socket.SetReadDeadline(time.Time{})
+	conn := wrappers.NewConn(socket, connID, wrappers.ConnPurposeClient, conf.PublicIPv4, conf.PublicIPv6)
 
 	obfs2, connOpts, err := obfuscated2.ParseObfuscated2ClientFrame(conf.Secret, frame)
 	if err != nil {
 		return nil, nil, errors.Annotate(err, "Cannot parse obfuscated frame")
 	}
 	connOpts.ConnectionProto = mtproto.ConnectionProtocolAny
-	connOpts.ClientAddr = conn.RemoteAddr().(*net.TCPAddr)
+	connOpts.ClientAddr = conn.RemoteAddr()
 
-	socket := wrappers.NewTimeoutRWC(conn, conf.PublicIPv4, conf.PublicIPv6)
-	socket = wrappers.NewStreamCipherRWC(socket, obfs2.Encryptor, obfs2.Decryptor)
+	conn = wrappers.NewStreamCipher(conn, obfs2.Encryptor, obfs2.Decryptor)
 
-	return connOpts, socket, nil
+	conn.Logger().Infow("Client connection initialized")
+
+	return conn, connOpts, nil
 }

client/middle.go

@@ -5,21 +5,25 @@ import (
 
 	"github.com/9seconds/mtg/config"
 	"github.com/9seconds/mtg/mtproto"
-	mtwrappers "github.com/9seconds/mtg/mtproto/wrappers"
 	"github.com/9seconds/mtg/wrappers"
 )
 
-func MiddleInit(conn net.Conn, conf *config.Config) (*mtproto.ConnectionOpts, wrappers.ReadWriteCloserWithAddr, error) {
-	opts, newConn, err := DirectInit(conn, conf)
+func MiddleInit(socket net.Conn, connID string, conf *config.Config) (wrappers.Wrap, *mtproto.ConnectionOpts, error) {
+	conn, opts, err := DirectInit(socket, connID, conf)
 	if err != nil {
 		return nil, nil, err
 	}
+	connStream := conn.(wrappers.StreamReadWriteCloser)
 
-	if opts.ConnectionType == mtproto.ConnectionTypeAbridged {
-		newConn = mtwrappers.NewAbridgedRWC(newConn, opts)
-	} else {
-		newConn = mtwrappers.NewIntermediateRWC(newConn, opts)
+	newConn := wrappers.NewMTProtoAbridged(connStream, opts)
+	if opts.ConnectionType != mtproto.ConnectionTypeAbridged {
+		newConn = wrappers.NewMTProtoIntermediate(connStream, opts)
 	}
 
-	return opts, newConn, nil
+	opts.ConnectionProto = mtproto.ConnectionProtocolIPv4
+	if socket.LocalAddr().(*net.TCPAddr).IP.To4() == nil {
+		opts.ConnectionProto = mtproto.ConnectionProtocolIPv6
+	}
+
+	return newConn, opts, err
 }

config/config.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"net"
 	"strconv"
-	"time"
 
 	"github.com/juju/errors"
 )
@@ -14,10 +13,6 @@ import (
 const (
 	BufferWriteSize = 32 * 1024
 	BufferReadSize  = 32 * 1024
-	BufferSizeCopy  = 32 * 1024
-
-	TimeoutRead  = time.Minute
-	TimeoutWrite = time.Minute
 )
 
 // Config represents common configuration of mtg.
@@ -63,6 +58,10 @@ func (c *Config) StatAddr() string {
 	return getAddr(c.StatsIP, c.StatsPort)
 }
 
+func (c *Config) UseMiddleProxy() bool {
+	return len(c.AdTag) > 0
+}
+
 // GetURLs returns configured IPURLs instance with links to this server.
 func (c *Config) GetURLs() IPURLs {
 	urls := IPURLs{}

main.go

@@ -111,16 +111,21 @@ func main() {
 		zapcore.NewJSONEncoder(encoderCfg),
 		zapcore.Lock(os.Stderr),
 		atom,
-	)).Sugar()
+	))
+	zap.ReplaceGlobals(logger)
+	defer logger.Sync()
 
-	stat := proxy.NewStats(conf)
-	go stat.Serve()
+	if conf.UseMiddleProxy() {
+		zap.S().Infow("Use middle proxy connection to Telegram")
+	} else {
+		zap.S().Infow("Use direct connection to Telegram")
+	}
 
-	srv := proxy.NewServer(conf, logger, stat)
 	printURLs(conf.GetURLs())
 
-	if err := srv.Serve(); err != nil {
-		logger.Fatal(err.Error())
+	server := proxy.NewProxy(conf)
+	if err := server.Serve(); err != nil {
+		zap.S().Fatalw("Server stopped", "error", err)
 	}
 }
 

mtproto/connection_options.go

@@ -13,14 +13,19 @@ type ConnectionType uint8
 
 type ConnectionProtocol uint8
 
+type Hacks struct {
+	SimpleAck bool
+	QuickAck  bool
+}
+
 // ConnectionOpts presents an options, metadata on connection requested
 // by the user on handshake.
 type ConnectionOpts struct {
 	DC              int16
 	ConnectionType  ConnectionType
 	ConnectionProto ConnectionProtocol
-	QuickAck        bool
-	SimpleAck       bool
+	ReadHacks       Hacks
+	WriteHacks      Hacks
 	ClientAddr      *net.TCPAddr
 }
 

mtproto/rpc/handshake_request.go

@@ -0,0 +1,22 @@
+package rpc
+
+import "bytes"
+
+type HandshakeRequest struct {
+}
+
+func (r *HandshakeRequest) Bytes() []byte {
+	buf := &bytes.Buffer{}
+	buf.Grow(len(TagHandshake) + len(HandshakeFlags) + len(HandshakeSenderPID) + len(HandshakePeerPID))
+
+	buf.Write(TagHandshake)
+	buf.Write(HandshakeFlags)
+	buf.Write(HandshakeSenderPID)
+	buf.Write(HandshakePeerPID)
+
+	return buf.Bytes()
+}
+
+func NewHandshakeRequest() *HandshakeRequest {
+	return &HandshakeRequest{}
+}

mtproto/rpc/rpc_handshake_response.go → mtproto/rpc/handshake_response.go

@@ -6,14 +6,14 @@ import (
 	"github.com/juju/errors"
 )
 
-type RPCHandshakeResponse struct {
+type HandshakeResponse struct {
 	Type      []byte
 	Flags     []byte
 	SenderPID []byte
 	PeerPID   []byte
 }
 
-func (r *RPCHandshakeResponse) Bytes() []byte {
+func (r *HandshakeResponse) Bytes() []byte {
 	buf := &bytes.Buffer{}
 
 	buf.Write(r.Type[:])
@@ -24,23 +24,23 @@ func (r *RPCHandshakeResponse) Bytes() []byte {
 	return buf.Bytes()
 }
 
-func (r *RPCHandshakeResponse) Valid(req *RPCHandshakeRequest) error {
-	if !bytes.Equal(r.Type, RPCTagHandshake) {
+func (r *HandshakeResponse) Valid(req *HandshakeRequest) error {
+	if !bytes.Equal(r.Type, TagHandshake) {
 		return errors.New("Unexpected handshake tag")
 	}
-	if !bytes.Equal(r.PeerPID, RPCHandshakeSenderPID) {
+	if !bytes.Equal(r.PeerPID, HandshakeSenderPID) {
 		return errors.New("Incorrect sender PID")
 	}
 
 	return nil
 }
 
-func NewRPCHandshakeResponse(data []byte) (*RPCHandshakeResponse, error) {
+func NewHandshakeResponse(data []byte) (*HandshakeResponse, error) {
 	if len(data) != 32 {
 		return nil, errors.New("Incorrect handshake response length")
 	}
 
-	return &RPCHandshakeResponse{
+	return &HandshakeResponse{
 		Type:      data[:4],
 		Flags:     data[4:8],
 		SenderPID: data[8:20],

mtproto/rpc/rpc_nonce_request.go → mtproto/rpc/nonce_request.go

@@ -9,25 +9,25 @@ import (
 	"github.com/juju/errors"
 )
 
-type RPCNonceRequest struct {
+type NonceRequest struct {
 	KeySelector []byte
 	CryptoTS    []byte
 	Nonce       []byte
 }
 
-func (r *RPCNonceRequest) Bytes() []byte {
+func (r *NonceRequest) Bytes() []byte {
 	buf := &bytes.Buffer{}
 
-	buf.Write(RPCTagNonce)
+	buf.Write(TagNonce)
 	buf.Write(r.KeySelector)
-	buf.Write(RPCNonceCryptoAES)
+	buf.Write(NonceCryptoAES)
 	buf.Write(r.CryptoTS)
 	buf.Write(r.Nonce)
 
 	return buf.Bytes()
 }
 
-func NewRPCNonceRequest(proxySecret []byte) (*RPCNonceRequest, error) {
+func NewNonceRequest(proxySecret []byte) (*NonceRequest, error) {
 	nonce := make([]byte, 16)
 	keySelector := make([]byte, 4)
 	cryptoTS := make([]byte, 4)
@@ -40,7 +40,7 @@ func NewRPCNonceRequest(proxySecret []byte) (*RPCNonceRequest, error) {
 	timestamp := time.Now().Truncate(time.Second).Unix() % 4294967296 // 256 ^ 4 - do not know how to name
 	binary.LittleEndian.PutUint32(cryptoTS, uint32(timestamp))
 
-	return &RPCNonceRequest{
+	return &NonceRequest{
 		KeySelector: keySelector,
 		CryptoTS:    cryptoTS,
 		Nonce:       nonce,

mtproto/rpc/rpc_nonce_response.go → mtproto/rpc/nonce_response.go

@@ -6,17 +6,17 @@ import (
 	"github.com/juju/errors"
 )
 
-type RPCNonceResponse struct {
-	RPCNonceRequest
+type NonceResponse struct {
+	NonceRequest
 
-	RPCType []byte
-	Crypto  []byte
+	Type   []byte
+	Crypto []byte
 }
 
-func (r *RPCNonceResponse) Bytes() []byte {
+func (r *NonceResponse) Bytes() []byte {
 	buf := &bytes.Buffer{}
 
-	buf.Write(r.RPCType)
+	buf.Write(r.Type)
 	buf.Write(r.KeySelector)
 	buf.Write(r.Crypto)
 	buf.Write(r.CryptoTS)
@@ -25,11 +25,11 @@ func (r *RPCNonceResponse) Bytes() []byte {
 	return buf.Bytes()
 }
 
-func (r *RPCNonceResponse) Valid(req *RPCNonceRequest) error {
-	if !bytes.Equal(r.RPCType, RPCTagNonce) {
+func (r *NonceResponse) Valid(req *NonceRequest) error {
+	if !bytes.Equal(r.Type, TagNonce) {
 		return errors.New("Unexpected RPC type")
 	}
-	if !bytes.Equal(r.Crypto, RPCNonceCryptoAES) {
+	if !bytes.Equal(r.Crypto, NonceCryptoAES) {
 		return errors.New("Unexpected crypto type")
 	}
 	if !bytes.Equal(r.KeySelector, req.KeySelector) {
@@ -39,18 +39,18 @@ func (r *RPCNonceResponse) Valid(req *RPCNonceRequest) error {
 	return nil
 }
 
-func NewRPCNonceResponse(data []byte) (*RPCNonceResponse, error) {
+func NewNonceResponse(data []byte) (*NonceResponse, error) {
 	if len(data) != 32 {
 		return nil, errors.New("Unexpected message length")
 	}
 
-	return &RPCNonceResponse{
-		RPCNonceRequest: RPCNonceRequest{
+	return &NonceResponse{
+		NonceRequest: NonceRequest{
 			KeySelector: data[4:8],
 			CryptoTS:    data[12:16],
 			Nonce:       data[16:],
 		},
-		RPCType: data[:4],
-		Crypto:  data[8:12],
+		Type:   data[:4],
+		Crypto: data[8:12],
 	}, nil
 }

mtproto/rpc/proxy_flags.go

@@ -0,0 +1,55 @@
+package rpc
+
+import (
+	"encoding/binary"
+	"strings"
+)
+
+type proxyRequestFlags uint32
+
+const (
+	proxyRequestFlagsHasAdTag     proxyRequestFlags = 0x8
+	proxyRequestFlagsEncrypted                      = 0x2
+	proxyRequestFlagsMagic                          = 0x1000
+	proxyRequestFlagsExtMode2                       = 0x20000
+	proxyRequestFlagsIntermediate                   = 0x20000000
+	proxyRequestFlagsAbdridged                      = 0x40000000
+	proxyRequestFlagsQuickAck                       = 0x80000000
+)
+
+var proxyRequestFlagsEncryptedPrefix [8]byte
+
+func (r proxyRequestFlags) Bytes() []byte {
+	converted := make([]byte, 4)
+	binary.LittleEndian.PutUint32(converted, uint32(r))
+
+	return converted
+}
+
+func (r proxyRequestFlags) String() string {
+	flags := make([]string, 0, 7)
+
+	if r&proxyRequestFlagsHasAdTag != 0 {
+		flags = append(flags, "HAS_AD_TAG")
+	}
+	if r&proxyRequestFlagsEncrypted != 0 {
+		flags = append(flags, "ENCRYPTED")
+	}
+	if r&proxyRequestFlagsMagic != 0 {
+		flags = append(flags, "MAGIC")
+	}
+	if r&proxyRequestFlagsExtMode2 != 0 {
+		flags = append(flags, "EXT_MODE_2")
+	}
+	if r&proxyRequestFlagsIntermediate != 0 {
+		flags = append(flags, "INTERMEDIATE")
+	}
+	if r&proxyRequestFlagsAbdridged != 0 {
+		flags = append(flags, "ABRIDGED")
+	}
+	if r&proxyRequestFlagsQuickAck != 0 {
+		flags = append(flags, "QUICK_ACK")
+	}
+
+	return strings.Join(flags, " | ")
+}

mtproto/rpc/proxy_request.go

@@ -0,0 +1,95 @@
+package rpc
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"net"
+
+	"github.com/juju/errors"
+
+	"github.com/9seconds/mtg/mtproto"
+)
+
+type ProxyRequest struct {
+	Flags        proxyRequestFlags
+	ConnectionID []byte
+	OurIPPort    []byte
+	ClientIPPort []byte
+	ADTag        []byte
+	Options      *mtproto.ConnectionOpts
+}
+
+func (r *ProxyRequest) MakeHeader(message []byte) (*bytes.Buffer, fmt.Stringer) {
+	bufferLength := len(TagProxyRequest) +
+		4 + // len(flags)
+		len(r.ConnectionID) +
+		len(r.ClientIPPort) +
+		len(r.OurIPPort) +
+		len(ProxyRequestExtraSize) +
+		len(ProxyRequestProxyTag) +
+		1 + // len(AdTag)
+		len(r.ADTag)
+	bufferLength += bufferLength % 4
+
+	buf := &bytes.Buffer{}
+	buf.Grow(bufferLength + len(message))
+
+	flags := r.Flags
+	if r.Options.ReadHacks.QuickAck {
+		flags |= proxyRequestFlagsQuickAck
+	}
+
+	if bytes.HasPrefix(message, proxyRequestFlagsEncryptedPrefix[:]) {
+		flags |= proxyRequestFlagsEncrypted
+	}
+
+	buf.Write(TagProxyRequest)
+	buf.Write(flags.Bytes())
+	buf.Write(r.ConnectionID)
+	buf.Write(r.ClientIPPort)
+	buf.Write(r.OurIPPort)
+	buf.Write(ProxyRequestExtraSize)
+	buf.Write(ProxyRequestProxyTag)
+	buf.WriteByte(byte(len(r.ADTag)))
+	buf.Write(r.ADTag)
+	buf.Write(make([]byte, (4-buf.Len()%4)%4))
+
+	return buf, flags
+}
+
+func NewProxyRequest(clientAddr, ownAddr *net.TCPAddr, opts *mtproto.ConnectionOpts, adTag []byte) (*ProxyRequest, error) {
+	flags := proxyRequestFlagsHasAdTag | proxyRequestFlagsMagic | proxyRequestFlagsExtMode2
+
+	switch opts.ConnectionType {
+	case mtproto.ConnectionTypeAbridged:
+		flags |= proxyRequestFlagsAbdridged
+	case mtproto.ConnectionTypeIntermediate:
+		flags |= proxyRequestFlagsIntermediate
+	}
+
+	request := &ProxyRequest{
+		Flags:        flags,
+		ADTag:        adTag,
+		Options:      opts,
+		ConnectionID: make([]byte, 8),
+		ClientIPPort: make([]byte, 16+4),
+		OurIPPort:    make([]byte, 16+4),
+	}
+
+	if _, err := rand.Read(request.ConnectionID); err != nil {
+		return nil, errors.Annotate(err, "Cannot generate connection ID")
+	}
+
+	port := [4]byte{}
+	copy(request.ClientIPPort[:16], clientAddr.IP.To16())
+	binary.LittleEndian.PutUint32(port[:], uint32(clientAddr.Port))
+	copy(request.ClientIPPort[16:], port[:])
+
+	copy(request.OurIPPort[:16], ownAddr.IP.To16())
+	binary.LittleEndian.PutUint32(port[:], uint32(ownAddr.Port))
+	copy(request.OurIPPort[16:], port[:])
+
+	return request, nil
+}

mtproto/rpc/rpc.go

@@ -1,30 +1,30 @@
 package rpc
 
 const (
-	RPCNonceSeqNo     = -2
-	RPCHandshakeSeqNo = -1
+	SeqNoNonce     = -2
+	SeqNoHandshake = -1
 )
 
 var (
-	RPCTagCloseExt     = []byte{0xa2, 0x34, 0xb6, 0x5e}
-	RPCTagProxyAns     = []byte{0x0d, 0xda, 0x03, 0x44}
-	RPCTagSimpleAck    = []byte{0x9b, 0x40, 0xac, 0x3b}
-	RPCTagHandshake    = []byte{0xf5, 0xee, 0x82, 0x76}
-	RPCTagNonce        = []byte{0xaa, 0x87, 0xcb, 0x7a}
-	RPCTagProxyRequest = []byte{0xee, 0xf1, 0xce, 0x36}
+	TagCloseExt     = []byte{0xa2, 0x34, 0xb6, 0x5e}
+	TagProxyAns     = []byte{0x0d, 0xda, 0x03, 0x44}
+	TagSimpleAck    = []byte{0x9b, 0x40, 0xac, 0x3b}
+	TagHandshake    = []byte{0xf5, 0xee, 0x82, 0x76}
+	TagNonce        = []byte{0xaa, 0x87, 0xcb, 0x7a}
+	TagProxyRequest = []byte{0xee, 0xf1, 0xce, 0x36}
 
-	RPCNonceCryptoAES = []byte{0x01, 0x00, 0x00, 0x00}
+	NonceCryptoAES = []byte{0x01, 0x00, 0x00, 0x00}
 
-	RPCHandshakeFlags = []byte{0x00, 0x00, 0x00, 0x00}
+	HandshakeFlags = []byte{0x00, 0x00, 0x00, 0x00}
 
-	RPCProxyRequestExtraSize = []byte{0x18, 0x00, 0x00, 0x00}
-	RPCProxyRequestProxyTag  = []byte{0xae, 0x26, 0x1e, 0xdb}
+	ProxyRequestExtraSize = []byte{0x18, 0x00, 0x00, 0x00}
+	ProxyRequestProxyTag  = []byte{0xae, 0x26, 0x1e, 0xdb}
 
-	RPCHandshakeSenderPID = []byte{}
-	RPCHandshakePeerPID   = []byte{}
+	HandshakeSenderPID []byte
+	HandshakePeerPID   []byte
 )
 
 func init() {
-	RPCHandshakeSenderPID = []byte("IPIPPRPDTIME")
-	RPCHandshakePeerPID = []byte("IPIPPRPDTIME")
+	HandshakeSenderPID = []byte("IPIPPRPDTIME")
+	HandshakePeerPID = []byte("IPIPPRPDTIME")
 }

mtproto/rpc/rpc_handshake_request.go

@@ -1,21 +0,0 @@
-package rpc
-
-import "bytes"
-
-type RPCHandshakeRequest struct {
-}
-
-func (r *RPCHandshakeRequest) Bytes() []byte {
-	buf := &bytes.Buffer{}
-
-	buf.Write(RPCTagHandshake)
-	buf.Write(RPCHandshakeFlags)
-	buf.Write(RPCHandshakeSenderPID)
-	buf.Write(RPCHandshakePeerPID)
-
-	return buf.Bytes()
-}
-
-func NewRPCHandshakeRequest() *RPCHandshakeRequest {
-	return &RPCHandshakeRequest{}
-}

mtproto/rpc/rpc_proxy_flags.go

@@ -1,24 +0,0 @@
-package rpc
-
-import "encoding/binary"
-
-type RPCProxyRequestFlags uint32
-
-const (
-	RPCProxyRequestFlagsHasAdTag     RPCProxyRequestFlags = 0x8
-	RPCProxyRequestFlagsEncrypted                         = 0x2
-	RPCProxyRequestFlagsMagic                             = 0x1000
-	RPCProxyRequestFlagsExtMode2                          = 0x20000
-	RPCProxyRequestFlagsIntermediate                      = 0x20000000
-	RPCProxyRequestFlagsAbdridged                         = 0x40000000
-	RPCProxyRequestFlagsQuickAck                          = 0x80000000
-)
-
-var rpcProxyRequestFlagsEncryptedPrefix [8]byte
-
-func (r RPCProxyRequestFlags) Bytes() []byte {
-	converted := make([]byte, 4)
-	binary.LittleEndian.PutUint32(converted, uint32(r))
-
-	return converted
-}

mtproto/rpc/rpc_proxy_request.go

@@ -1,83 +0,0 @@
-package rpc
-
-import (
-	"bytes"
-	"crypto/rand"
-	"encoding/binary"
-	"net"
-
-	"github.com/juju/errors"
-
-	"github.com/9seconds/mtg/mtproto"
-)
-
-type RPCProxyRequest struct {
-	Flags        RPCProxyRequestFlags
-	ConnectionID []byte
-	OurIPPort    []byte
-	ClientIPPort []byte
-	ADTag        []byte
-	Options      *mtproto.ConnectionOpts
-}
-
-func (r *RPCProxyRequest) Bytes(message []byte) []byte {
-	buf := &bytes.Buffer{}
-
-	flags := r.Flags
-	if r.Options.QuickAck {
-		flags |= RPCProxyRequestFlagsQuickAck
-	}
-
-	if bytes.HasPrefix(message, rpcProxyRequestFlagsEncryptedPrefix[:]) {
-		flags |= RPCProxyRequestFlagsEncrypted
-	}
-
-	buf.Write(RPCTagProxyRequest)
-	buf.Write(flags.Bytes())
-	buf.Write(r.ConnectionID[:])
-	buf.Write(r.ClientIPPort[:])
-	buf.Write(r.OurIPPort[:])
-	buf.Write(RPCProxyRequestExtraSize)
-	buf.Write(RPCProxyRequestProxyTag)
-	buf.WriteByte(byte(len(r.ADTag)))
-	buf.Write(r.ADTag)
-	buf.Write(bytes.Repeat([]byte{0x00}, buf.Len()%4))
-	buf.Write(message)
-
-	return buf.Bytes()
-}
-
-func NewRPCProxyRequest(clientAddr, ownAddr *net.TCPAddr, opts *mtproto.ConnectionOpts, adTag []byte) (*RPCProxyRequest, error) {
-	flags := RPCProxyRequestFlagsHasAdTag | RPCProxyRequestFlagsMagic | RPCProxyRequestFlagsExtMode2
-
-	switch opts.ConnectionType {
-	case mtproto.ConnectionTypeAbridged:
-		flags |= RPCProxyRequestFlagsAbdridged
-	case mtproto.ConnectionTypeIntermediate:
-		flags |= RPCProxyRequestFlagsIntermediate
-	}
-
-	request := RPCProxyRequest{
-		Flags:        flags,
-		ADTag:        adTag,
-		Options:      opts,
-		ConnectionID: make([]byte, 8),
-		ClientIPPort: make([]byte, 16+4),
-		OurIPPort:    make([]byte, 16+4),
-	}
-
-	if _, err := rand.Read(request.ConnectionID); err != nil {
-		return nil, errors.Annotate(err, "Cannot generate connection ID")
-	}
-
-	port := [4]byte{}
-	copy(request.ClientIPPort[:16], clientAddr.IP.To16())
-	binary.LittleEndian.PutUint32(port[:], uint32(clientAddr.Port))
-	copy(request.ClientIPPort[16:], port[:])
-
-	copy(request.OurIPPort[:16], ownAddr.IP.To16())
-	binary.LittleEndian.PutUint32(port[:], uint32(ownAddr.Port))
-	copy(request.OurIPPort[16:], port[:])
-
-	return &request, nil
-}

mtproto/wrappers/abridged.go

@@ -1,121 +0,0 @@
-package wrappers
-
-import (
-	"bytes"
-	"encoding/binary"
-	"io"
-	"net"
-
-	"github.com/juju/errors"
-
-	"github.com/9seconds/mtg/mtproto"
-	"github.com/9seconds/mtg/wrappers"
-)
-
-type uint24 [3]byte
-
-const (
-	abridgedSmallPacketLength = 0x7f
-	abridgedQuickAckLength    = 0x80
-	abridgedLargePacketLength = 16777216 // 256 ^ 3
-)
-
-type AbridgedReadWriteCloserWithAddr struct {
-	wrappers.BufferedReader
-
-	conn wrappers.ReadWriteCloserWithAddr
-	opts *mtproto.ConnectionOpts
-}
-
-func (a *AbridgedReadWriteCloserWithAddr) Read(p []byte) (int, error) {
-	return a.BufferedRead(p, func() error {
-		var msgLength uint8
-		if err := binary.Read(a.conn, binary.LittleEndian, &msgLength); err != nil {
-			return errors.Annotate(err, "Cannot read message length")
-		}
-
-		a.opts.QuickAck = false
-		if msgLength >= abridgedQuickAckLength {
-			a.opts.QuickAck = true
-			msgLength -= 0x80
-		}
-
-		msgLength32 := uint32(msgLength)
-		if msgLength == abridgedSmallPacketLength {
-			buf := &bytes.Buffer{}
-			buf.Grow(3)
-
-			if _, err := io.CopyN(buf, a.conn, 3); err != nil {
-				return errors.Annotate(err, "Cannot read correct message length")
-			}
-			number := uint24{}
-			copy(number[:], buf.Bytes())
-			msgLength32 = fromUint24(number)
-		}
-		msgLength32 *= 4
-
-		if _, err := io.CopyN(a.Buffer, a.conn, int64(msgLength32)); err != nil {
-			return errors.Annotate(err, "Cannot read message")
-		}
-
-		return nil
-	})
-}
-
-func (a *AbridgedReadWriteCloserWithAddr) Write(p []byte) (int, error) {
-	if len(p)%4 != 0 {
-		return 0, errors.Errorf("Incorrect packet length %d", len(p))
-	}
-	if a.opts.SimpleAck {
-		return a.conn.Write(reverseBytes(p))
-	}
-
-	packetLength := len(p) / 4
-	switch {
-	case packetLength < abridgedSmallPacketLength:
-		newData := append([]byte{byte(packetLength)}, p...)
-		return a.conn.Write(newData)
-
-	case packetLength < abridgedLargePacketLength:
-		length24 := toUint24(uint32(packetLength))
-
-		buf := &bytes.Buffer{}
-		buf.Grow(1 + 3 + len(p))
-		buf.WriteByte(byte(abridgedSmallPacketLength))
-		buf.Write(length24[:])
-		buf.Write(p)
-
-		return a.conn.Write(buf.Bytes())
-
-	default:
-		return 0, errors.Errorf("Packet is too big %d", len(p))
-	}
-}
-
-func (a *AbridgedReadWriteCloserWithAddr) Close() error {
-	return a.conn.Close()
-}
-
-func (a *AbridgedReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return a.conn.LocalAddr()
-}
-
-func (a *AbridgedReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return a.conn.RemoteAddr()
-}
-
-func toUint24(number uint32) uint24 {
-	return uint24{byte(number), byte(number >> 8), byte(number >> 16)}
-}
-
-func fromUint24(number uint24) uint32 {
-	return uint32(number[0]) + (uint32(number[1]) << 8) + (uint32(number[2]) << 16)
-}
-
-func NewAbridgedRWC(conn wrappers.ReadWriteCloserWithAddr, connOpts *mtproto.ConnectionOpts) wrappers.ReadWriteCloserWithAddr {
-	return &AbridgedReadWriteCloserWithAddr{
-		BufferedReader: wrappers.NewBufferedReader(),
-		conn:           conn,
-		opts:           connOpts,
-	}
-}

mtproto/wrappers/crypt_test.go

@@ -1,45 +0,0 @@
-package wrappers
-
-import (
-	"encoding/binary"
-	"net"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-
-	"github.com/9seconds/mtg/mtproto/rpc"
-)
-
-var proxySecret = []byte{196, 249, 250, 202, 150, 120, 230, 187, 72, 173,
-	108, 126, 44, 229, 192, 210, 68, 48, 100, 93, 85, 74, 221, 235, 85, 65,
-	158, 3, 77, 166, 39, 33, 208, 70, 234, 171, 110, 82, 171, 20, 169, 90, 68,
-	62, 207, 179, 70, 62, 121, 160, 90, 102, 97, 42, 223, 156, 174, 218, 139,
-	233, 168, 13, 166, 152, 111, 176, 166, 255, 56, 122, 248, 77, 136, 239,
-	58, 100, 19, 113, 62, 92, 51, 119, 246, 225, 163, 212, 125, 153, 245, 224,
-	197, 110, 236, 232, 240, 92, 84, 196, 144, 176, 121, 227, 27, 239, 130,
-	255, 14, 232, 242, 176, 163, 39, 86, 210, 73, 197, 242, 18, 105, 129, 108,
-	183, 6, 27, 38, 93, 178, 18}
-
-func TestMakeKeys(t *testing.T) {
-	req, err := rpc.NewRPCNonceRequest(proxySecret)
-	assert.Nil(t, err)
-
-	copy(req.Nonce[:], []byte{24, 49, 53, 111, 198, 10, 235, 180, 230, 112, 92, 78, 1, 201, 106, 105})
-	binary.LittleEndian.PutUint32(req.CryptoTS[:], 1528396015)
-
-	resp := &rpc.RPCNonceResponse{}
-	copy(resp.Nonce[:], []byte{247, 40, 210, 56, 65, 12, 101, 170, 216, 155, 14, 253, 250, 238, 219, 226})
-
-	cltAddr := &net.TCPAddr{
-		IP:   net.ParseIP("80.211.29.34"),
-		Port: 54208,
-	}
-	srvAddr := &net.TCPAddr{
-		IP:   net.ParseIP("149.154.162.38"),
-		Port: 80,
-	}
-
-	key, iv := makeKeys(CipherPurposeClient, req, resp, cltAddr, srvAddr, proxySecret)
-	assert.Equal(t, key, []byte{165, 158, 127, 49, 41, 232, 187, 69, 38, 29, 163, 226, 183, 146, 28, 67, 225, 224, 134, 191, 207, 152, 255, 166, 152, 66, 169, 196, 54, 135, 50, 188})
-	assert.Equal(t, iv, []byte{33, 110, 125, 221, 183, 121, 160, 116, 130, 180, 156, 249, 52, 111, 37, 178})
-}

mtproto/wrappers/frame.go

@@ -1,130 +0,0 @@
-package wrappers
-
-import (
-	"bytes"
-	"crypto/aes"
-	"encoding/binary"
-	"hash/crc32"
-	"io"
-	"io/ioutil"
-	"net"
-
-	"github.com/juju/errors"
-
-	"github.com/9seconds/mtg/wrappers"
-)
-
-// Frame: { MessageLength(4) | SequenceNumber(4) | Message(???) | CRC32(4) [| padding(4), ...] }
-const (
-	frameRWCMinMessageLength = 12
-	frameRWCMaxMessageLength = 16777216
-)
-
-var frameRWCPadding = [4]byte{0x04, 0x00, 0x00, 0x00}
-
-type FrameRWC struct {
-	wrappers.BufferedReader
-
-	conn       wrappers.ReadWriteCloserWithAddr
-	readSeqNo  int32
-	writeSeqNo int32
-}
-
-func (f *FrameRWC) Write(buf []byte) (int, error) {
-	writeBuf := &bytes.Buffer{}
-
-	// 4 - len bytes
-	// 4 - seq bytes
-	// . - message
-	// 4 - crc32
-	messageLength := 4 + 4 + len(buf) + 4
-	paddingLength := (aes.BlockSize - messageLength%aes.BlockSize) % aes.BlockSize
-	writeBuf.Grow(messageLength + paddingLength)
-
-	binary.Write(writeBuf, binary.LittleEndian, uint32(messageLength))
-	binary.Write(writeBuf, binary.LittleEndian, f.writeSeqNo)
-	writeBuf.Write(buf)
-	f.writeSeqNo++
-
-	checksum := crc32.ChecksumIEEE(writeBuf.Bytes())
-	binary.Write(writeBuf, binary.LittleEndian, checksum)
-	writeBuf.Write(bytes.Repeat(frameRWCPadding[:], paddingLength/4))
-
-	_, err := f.conn.Write(writeBuf.Bytes())
-	return len(buf), err
-}
-
-func (f *FrameRWC) Read(p []byte) (int, error) {
-	return f.BufferedRead(p, func() error {
-		buf := &bytes.Buffer{}
-		sum := crc32.NewIEEE()
-		writer := io.MultiWriter(buf, sum)
-
-		for {
-			buf.Reset()
-			sum.Reset()
-			if _, err := io.CopyN(writer, f.conn, 4); err != nil {
-				return errors.Annotate(err, "Cannot read frame padding")
-			}
-			if !bytes.Equal(buf.Bytes(), frameRWCPadding[:]) {
-				break
-			}
-		}
-
-		messageLength := binary.LittleEndian.Uint32(buf.Bytes())
-		if messageLength%4 != 0 || messageLength < frameRWCMinMessageLength || messageLength > frameRWCMaxMessageLength {
-			return errors.Errorf("Incorrect frame message length %d", messageLength)
-		}
-
-		buf.Reset()
-		buf.Grow(int(messageLength) - 4 - 4)
-		if _, err := io.CopyN(writer, f.conn, int64(messageLength)-4-4); err != nil {
-			return errors.Annotate(err, "Cannot read the message frame")
-		}
-
-		var seqNo int32
-		binary.Read(buf, binary.LittleEndian, &seqNo)
-		if seqNo != f.readSeqNo {
-			return errors.Errorf("Unexpected sequence number %d (wait for %d)", seqNo, f.readSeqNo)
-		}
-		f.readSeqNo++
-
-		data, _ := ioutil.ReadAll(buf)
-		buf.Reset()
-		// write to buf, not to writer. This is because we are going to fetch
-		// crc32 checksum.
-		if _, err := io.CopyN(buf, f.conn, 4); err != nil {
-			return errors.Annotate(err, "Cannot read checksum")
-		}
-		checksum := binary.LittleEndian.Uint32(buf.Bytes())
-
-		if checksum != sum.Sum32() {
-			return errors.Errorf("CRC32 checksum mismatch. Wait for %d, got %d", sum.Sum32(), checksum)
-
-		}
-		f.Buffer.Write(data)
-
-		return nil
-	})
-}
-
-func (f *FrameRWC) Close() error {
-	return f.conn.Close()
-}
-
-func (f *FrameRWC) LocalAddr() *net.TCPAddr {
-	return f.conn.LocalAddr()
-}
-
-func (f *FrameRWC) RemoteAddr() *net.TCPAddr {
-	return f.conn.RemoteAddr()
-}
-
-func NewFrameRWC(conn wrappers.ReadWriteCloserWithAddr, seqNo int32) wrappers.ReadWriteCloserWithAddr {
-	return &FrameRWC{
-		BufferedReader: wrappers.NewBufferedReader(),
-		conn:           conn,
-		readSeqNo:      seqNo,
-		writeSeqNo:     seqNo,
-	}
-}

mtproto/wrappers/intermediate.go

@@ -1,83 +0,0 @@
-package wrappers
-
-import (
-	"bytes"
-	"encoding/binary"
-	"io"
-	"net"
-
-	"github.com/juju/errors"
-
-	"github.com/9seconds/mtg/mtproto"
-	"github.com/9seconds/mtg/wrappers"
-)
-
-const intermediateQuickAckLength = 0x80000000
-
-type IntermediateReadWriteCloserWithAddr struct {
-	wrappers.BufferedReader
-
-	conn wrappers.ReadWriteCloserWithAddr
-	opts *mtproto.ConnectionOpts
-}
-
-func (i *IntermediateReadWriteCloserWithAddr) Read(p []byte) (int, error) {
-	return i.BufferedRead(p, func() error {
-		var length uint32
-		if err := binary.Read(i.conn, binary.LittleEndian, &length); err != nil {
-			return errors.Annotate(err, "Cannot read message length")
-		}
-
-		if length > intermediateQuickAckLength {
-			i.opts.QuickAck = true
-			length -= intermediateQuickAckLength
-		}
-
-		buf := &bytes.Buffer{}
-		buf.Grow(int(length))
-		if _, err := io.CopyN(buf, i.conn, int64(length)); err != nil {
-			return errors.Annotate(err, "Cannot read the message")
-		}
-
-		if length%4 != 0 {
-			length -= length % 4
-			i.Buffer.Write(buf.Bytes()[:length])
-			return nil
-		}
-
-		i.Buffer.Write(buf.Bytes())
-
-		return nil
-	})
-}
-
-func (i *IntermediateReadWriteCloserWithAddr) Write(p []byte) (int, error) {
-	if i.opts.SimpleAck {
-		return i.conn.Write(p)
-	}
-
-	var length [4]byte
-	binary.LittleEndian.PutUint32(length[:], uint32(len(p)))
-
-	return i.conn.Write(append(length[:], p...))
-}
-
-func (i *IntermediateReadWriteCloserWithAddr) Close() error {
-	return i.conn.Close()
-}
-
-func (i *IntermediateReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return i.conn.LocalAddr()
-}
-
-func (i *IntermediateReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return i.conn.RemoteAddr()
-}
-
-func NewIntermediateRWC(conn wrappers.ReadWriteCloserWithAddr, connOpts *mtproto.ConnectionOpts) wrappers.ReadWriteCloserWithAddr {
-	return &IntermediateReadWriteCloserWithAddr{
-		BufferedReader: wrappers.NewBufferedReader(),
-		conn:           conn,
-		opts:           connOpts,
-	}
-}

mtproto/wrappers/proxy_request.go

@@ -1,112 +0,0 @@
-package wrappers
-
-import (
-	"bytes"
-	"io"
-	"io/ioutil"
-	"net"
-
-	"github.com/juju/errors"
-
-	"github.com/9seconds/mtg/mtproto"
-	"github.com/9seconds/mtg/mtproto/rpc"
-	"github.com/9seconds/mtg/wrappers"
-)
-
-type ProxyRequestReadWriteCloserWithAddr struct {
-	wrappers.BufferedReader
-
-	conn wrappers.ReadWriteCloserWithAddr
-	req  *rpc.RPCProxyRequest
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) Read(buf []byte) (int, error) {
-	return p.BufferedRead(buf, func() error {
-		ansBuf := &bytes.Buffer{}
-		ansBuf.Grow(4)
-
-		if _, err := io.CopyN(ansBuf, p.conn, 4); err != nil {
-			return errors.Annotate(err, "Cannot read RPC tag")
-		}
-
-		if bytes.Equal(ansBuf.Bytes(), rpc.RPCTagCloseExt) {
-			return p.readCloseExt()
-		} else if bytes.Equal(ansBuf.Bytes(), rpc.RPCTagProxyAns) {
-			return p.readProxyAns(buf)
-		} else if bytes.Equal(ansBuf.Bytes(), rpc.RPCTagSimpleAck) {
-			return p.readSimpleAck()
-		}
-
-		return nil
-	})
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) readCloseExt() error {
-	return errors.New("Connection has been closed remotely")
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) readProxyAns(buf []byte) error {
-	if _, err := io.CopyN(ioutil.Discard, p.conn, 8+4); err != nil {
-		return errors.Annotate(err, "Cannot skip flags and connid")
-	}
-
-	for {
-		n, err := p.conn.Read(buf)
-		if err != nil {
-			return errors.Annotate(err, "Cannot read proxy answer")
-		}
-		if n == 0 {
-			break
-		}
-		p.Buffer.Write(buf[:n])
-	}
-
-	return nil
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) readSimpleAck() error {
-	if _, err := io.CopyN(ioutil.Discard, p.conn, 8); err != nil {
-		return errors.Annotate(err, "Cannot skip connid")
-	}
-	if _, err := io.CopyN(p.Buffer, p.conn, 4); err != nil {
-		return errors.Annotate(err, "Cannot read simple ack")
-	}
-	p.req.Options.SimpleAck = true
-
-	return nil
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) Write(raw []byte) (int, error) {
-	if _, err := p.conn.Write(p.req.Bytes(raw)); err != nil {
-		return 0, err
-	}
-	p.req.Options.SimpleAck = false
-	p.req.Options.QuickAck = false
-
-	return len(raw), nil
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) Close() error {
-	return p.conn.Close()
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return p.conn.LocalAddr()
-}
-
-func (p *ProxyRequestReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return p.conn.RemoteAddr()
-}
-
-func NewProxyRequestRWC(conn wrappers.ReadWriteCloserWithAddr, connOpts *mtproto.ConnectionOpts, adTag []byte) (wrappers.ReadWriteCloserWithAddr, error) {
-	req, err := rpc.NewRPCProxyRequest(connOpts.ClientAddr, conn.LocalAddr(), connOpts, adTag)
-	if err != nil {
-		return nil, errors.Annotate(err, "Cannot create new RPC proxy request")
-	}
-
-	return &ProxyRequestReadWriteCloserWithAddr{
-		BufferedReader: wrappers.NewBufferedReader(),
-		conn:           conn,
-		req:            req,
-	}, nil
-}

proxy/copy_pool.go

@@ -1,18 +0,0 @@
-package proxy
-
-import (
-	"sync"
-
-	"github.com/9seconds/mtg/config"
-)
-
-var copyPool sync.Pool
-
-func init() {
-	copyPool = sync.Pool{
-		New: func() interface{} {
-			data := make([]byte, config.BufferSizeCopy)
-			return &data
-		},
-	}
-}

proxy/proxy.go

@@ -0,0 +1,154 @@
+package proxy
+
+import (
+	"io"
+	"net"
+	"sync"
+
+	"github.com/juju/errors"
+	uuid "github.com/satori/go.uuid"
+	"go.uber.org/zap"
+
+	"github.com/9seconds/mtg/client"
+	"github.com/9seconds/mtg/config"
+	"github.com/9seconds/mtg/mtproto"
+	"github.com/9seconds/mtg/telegram"
+	"github.com/9seconds/mtg/wrappers"
+)
+
+type Proxy struct {
+	clientInit client.Init
+	tg         telegram.Telegram
+	conf       *config.Config
+}
+
+func (p *Proxy) Serve() error {
+	lsock, err := net.Listen("tcp", p.conf.BindAddr())
+	if err != nil {
+		return errors.Annotate(err, "Cannot create listen socket")
+	}
+
+	for {
+		if conn, err := lsock.Accept(); err != nil {
+			zap.S().Errorw("Cannot allocate incoming connection", "error", err)
+		} else {
+			go p.accept(conn)
+		}
+	}
+}
+
+func (p *Proxy) accept(conn net.Conn) {
+	connID := uuid.NewV4().String()
+	log := zap.S().With("connection_id", connID)
+
+	defer func() {
+		conn.Close()
+
+		if err := recover(); err != nil {
+			log.Errorw("Crash of accept handler", "error", err)
+		}
+	}()
+
+	log.Infow("Client connected", "addr", conn.RemoteAddr())
+
+	client, opts, err := p.clientInit(conn, connID, p.conf)
+	if err != nil {
+		log.Errorw("Cannot initialize client connection", "error", err)
+		return
+	}
+	defer client.(io.Closer).Close()
+
+	server, err := p.getTelegramConn(opts, connID)
+	if err != nil {
+		log.Errorw("Cannot initialize server connection", "error", err)
+		return
+	}
+	defer server.(io.Closer).Close()
+
+	wait := &sync.WaitGroup{}
+	wait.Add(2)
+
+	if p.conf.UseMiddleProxy() {
+		clientPacket := client.(wrappers.PacketReadWriteCloser)
+		serverPacket := server.(wrappers.PacketReadWriteCloser)
+		go p.middlePipe(clientPacket, serverPacket, wait, &opts.ReadHacks)
+		go p.middlePipe(serverPacket, clientPacket, wait, &opts.WriteHacks)
+	} else {
+		clientStream := client.(wrappers.StreamReadWriteCloser)
+		serverStream := server.(wrappers.StreamReadWriteCloser)
+		go p.directPipe(clientStream, serverStream, wait)
+		go p.directPipe(serverStream, clientStream, wait)
+	}
+
+	wait.Wait()
+
+	log.Infow("Client disconnected", "addr", conn.RemoteAddr())
+}
+
+func (p *Proxy) getTelegramConn(opts *mtproto.ConnectionOpts, connID string) (wrappers.Wrap, error) {
+	streamConn, err := p.tg.Dial(connID, opts)
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot dial to Telegram")
+	}
+
+	packetConn, err := p.tg.Init(opts, streamConn)
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot handshake telegram")
+	}
+
+	return packetConn, nil
+}
+
+func (p *Proxy) middlePipe(src wrappers.PacketReadCloser, dst wrappers.PacketWriteCloser, wait *sync.WaitGroup, hacks *mtproto.Hacks) {
+	defer func() {
+		src.Close()
+		dst.Close()
+		wait.Done()
+	}()
+
+	for {
+		hacks.SimpleAck = false
+		hacks.QuickAck = false
+
+		packet, err := src.Read()
+		if err != nil {
+			src.Logger().Warnw("Cannot read packet", "error", err)
+			return
+		}
+		if _, err = dst.Write(packet); err != nil {
+			src.Logger().Warnw("Cannot write packet", "error", err)
+			return
+		}
+	}
+}
+
+func (p *Proxy) directPipe(src wrappers.StreamReadCloser, dst wrappers.StreamWriteCloser, wait *sync.WaitGroup) {
+	defer func() {
+		src.Close()
+		dst.Close()
+		wait.Done()
+	}()
+
+	if _, err := io.Copy(dst, src); err != nil {
+		src.Logger().Warnw("Cannot pump sockets", "error", err)
+	}
+}
+
+func NewProxy(conf *config.Config) *Proxy {
+	var clientInit client.Init
+	var tg telegram.Telegram
+
+	if conf.UseMiddleProxy() {
+		clientInit = client.MiddleInit
+		tg = telegram.NewMiddleTelegram(conf)
+	} else {
+		clientInit = client.DirectInit
+		tg = telegram.NewDirectTelegram(conf)
+	}
+
+	return &Proxy{
+		conf:       conf,
+		clientInit: clientInit,
+		tg:         tg,
+	}
+}

proxy/server.go

@@ -1,157 +0,0 @@
-package proxy
-
-import (
-	"context"
-	"io"
-	"net"
-	"sync"
-
-	"github.com/juju/errors"
-	uuid "github.com/satori/go.uuid"
-	"go.uber.org/zap"
-
-	"github.com/9seconds/mtg/client"
-	"github.com/9seconds/mtg/config"
-	"github.com/9seconds/mtg/mtproto"
-	"github.com/9seconds/mtg/telegram"
-	"github.com/9seconds/mtg/wrappers"
-)
-
-// Server is an insgtance of MTPROTO proxy.
-type Server struct {
-	conf       *config.Config
-	logger     *zap.SugaredLogger
-	stats      *Stats
-	tg         telegram.Telegram
-	clientInit client.Init
-}
-
-// Serve does MTPROTO proxying.
-func (s *Server) Serve() error {
-	lsock, err := net.Listen("tcp", s.conf.BindAddr())
-	if err != nil {
-		return errors.Annotate(err, "Cannot create listen socket")
-	}
-
-	for {
-		if conn, err := lsock.Accept(); err != nil {
-			s.logger.Warn("Cannot allocate incoming connection", "error", err)
-		} else {
-			go s.accept(conn)
-		}
-	}
-}
-
-func (s *Server) accept(conn net.Conn) {
-	defer func() {
-		s.stats.closeConnection()
-		conn.Close() // nolint: errcheck
-
-		if r := recover(); r != nil {
-			s.logger.Errorw("Crash of accept handler", "error", r)
-		}
-	}()
-
-	s.stats.newConnection()
-	ctx, cancel := context.WithCancel(context.Background())
-	socketID := uuid.NewV4().String()
-
-	s.logger.Debugw("Client connected",
-		"addr", conn.RemoteAddr().String(),
-		"socketid", socketID,
-	)
-
-	connOpts, clientConn, err := s.getClientStream(ctx, cancel, conn, socketID)
-	if err != nil {
-		s.logger.Warnw("Cannot initialize client connection",
-			"addr", conn.RemoteAddr().String(),
-			"socketid", socketID,
-			"error", err,
-		)
-		return
-	}
-	defer clientConn.Close() // nolint: errcheck
-
-	tgConn, err := s.getTelegramStream(ctx, cancel, connOpts, socketID)
-	if err != nil {
-		s.logger.Warnw("Cannot initialize Telegram connection",
-			"socketid", socketID,
-			"error", err,
-		)
-		return
-	}
-	defer tgConn.Close() // nolint: errcheck
-
-	wait := &sync.WaitGroup{}
-	wait.Add(2)
-
-	go s.pipe(clientConn, tgConn, wait)
-	go s.pipe(tgConn, clientConn, wait)
-
-	<-ctx.Done()
-	wait.Wait()
-
-	s.logger.Debugw("Client disconnected",
-		"addr", conn.RemoteAddr().String(),
-		"socketid", socketID,
-	)
-}
-
-func (s *Server) getClientStream(ctx context.Context, cancel context.CancelFunc, conn net.Conn, socketID string) (*mtproto.ConnectionOpts, io.ReadWriteCloser, error) {
-	connOpts, socket, err := s.clientInit(conn, s.conf)
-	if err != nil {
-		return nil, nil, errors.Annotate(err, "Cannot init client connection")
-	}
-
-	socket = wrappers.NewTrafficRWC(socket, s.stats.addIncomingTraffic, s.stats.addOutgoingTraffic)
-	socket = wrappers.NewLogRWC(socket, s.logger, socketID, "client")
-	socket = wrappers.NewCtxRWC(ctx, cancel, socket)
-
-	return connOpts, socket, nil
-}
-
-func (s *Server) getTelegramStream(ctx context.Context, cancel context.CancelFunc, connOpts *mtproto.ConnectionOpts, socketID string) (io.ReadWriteCloser, error) {
-	conn, err := s.tg.Dial(connOpts)
-	if err != nil {
-		return nil, errors.Annotate(err, "Cannot connect to Telegram")
-	}
-
-	conn = wrappers.NewTrafficRWC(conn, s.stats.addIncomingTraffic, s.stats.addOutgoingTraffic)
-	conn, err = s.tg.Init(connOpts, conn)
-	if err != nil {
-		return nil, errors.Annotate(err, "Cannot handshake Telegram")
-	}
-
-	conn = wrappers.NewLogRWC(conn, s.logger, socketID, "telegram")
-	conn = wrappers.NewCtxRWC(ctx, cancel, conn)
-
-	return conn, nil
-}
-
-func (s *Server) pipe(dst io.Writer, src io.Reader, wait *sync.WaitGroup) {
-	defer wait.Done()
-
-	buf := copyPool.Get().(*[]byte)
-	defer copyPool.Put(buf)
-
-	io.CopyBuffer(dst, src, *buf) // nolint: errcheck
-}
-
-// NewServer creates new instance of MTPROTO proxy.
-func NewServer(conf *config.Config, logger *zap.SugaredLogger, stat *Stats) *Server {
-	clientInit := client.DirectInit
-	tg := telegram.NewDirectTelegram
-
-	if len(conf.AdTag) > 0 {
-		clientInit = client.MiddleInit
-		tg = telegram.NewMiddleTelegram
-	}
-
-	return &Server{
-		conf:       conf,
-		logger:     logger,
-		stats:      stat,
-		tg:         tg(conf, logger),
-		clientInit: clientInit,
-	}
-}

proxy/stats.go

@@ -1,74 +0,0 @@
-package proxy
-
-import (
-	"encoding/json"
-	"net/http"
-	"strconv"
-	"sync/atomic"
-	"time"
-
-	"github.com/9seconds/mtg/config"
-)
-
-type statsUptime time.Time
-
-func (s statsUptime) MarshalJSON() ([]byte, error) {
-	uptime := int(time.Since(time.Time(s)).Seconds())
-	return []byte(strconv.Itoa(uptime)), nil
-}
-
-// Stats is a datastructure for statistics on work of this proxy.
-type Stats struct {
-	AllConnections    uint64 `json:"all_connections"`
-	ActiveConnections uint32 `json:"active_connections"`
-	Traffic           struct {
-		Incoming uint64 `json:"incoming"`
-		Outgoing uint64 `json:"outgoing"`
-	} `json:"traffic"`
-	URLs   config.IPURLs `json:"urls"`
-	Uptime statsUptime   `json:"uptime"`
-
-	conf *config.Config
-}
-
-func (s *Stats) newConnection() {
-	atomic.AddUint64(&s.AllConnections, 1)
-	atomic.AddUint32(&s.ActiveConnections, 1)
-}
-
-func (s *Stats) closeConnection() {
-	atomic.AddUint32(&s.ActiveConnections, ^uint32(0))
-}
-
-func (s *Stats) addIncomingTraffic(n int) {
-	atomic.AddUint64(&s.Traffic.Incoming, uint64(n))
-}
-
-func (s *Stats) addOutgoingTraffic(n int) {
-	atomic.AddUint64(&s.Traffic.Outgoing, uint64(n))
-}
-
-// Serve runs statistics HTTP server.
-func (s *Stats) Serve() {
-	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-
-		encoder := json.NewEncoder(w)
-		encoder.SetEscapeHTML(false)
-		encoder.SetIndent("", "  ")
-		encoder.Encode(s) // nolint: errcheck, gas
-	})
-
-	http.ListenAndServe(s.conf.StatAddr(), nil) // nolint: errcheck, gas
-}
-
-// NewStats returns new instance of statistics datastructure.
-func NewStats(conf *config.Config) *Stats {
-	stat := &Stats{
-		Uptime: statsUptime(time.Now()),
-		conf:   conf,
-	}
-	stat.URLs = conf.GetURLs()
-
-	return stat
-}

telegram/dialer.go

@@ -30,11 +30,12 @@ func (t *tgDialer) dial(addr string) (net.Conn, error) {
 	return conn, nil
 }
 
-func (t *tgDialer) dialRWC(addr string) (wrappers.ReadWriteCloserWithAddr, error) {
+func (t *tgDialer) dialRWC(addr, connID string) (wrappers.StreamReadWriteCloser, error) {
 	conn, err := t.dial(addr)
 	if err != nil {
 		return nil, err
 	}
+	tgConn := wrappers.NewConn(conn, connID, wrappers.ConnPurposeTelegram, t.conf.PublicIPv4, t.conf.PublicIPv6)
 
-	return wrappers.NewTimeoutRWC(conn, t.conf.PublicIPv4, t.conf.PublicIPv6), nil
+	return tgConn, nil
 }

telegram/direct.go

@@ -4,7 +4,6 @@ import (
 	"net"
 
 	"github.com/juju/errors"
-	"go.uber.org/zap"
 
 	"github.com/9seconds/mtg/config"
 	"github.com/9seconds/mtg/mtproto"
@@ -29,11 +28,11 @@ var (
 	}
 )
 
-type directTelegram struct {
+type DirectTelegram struct {
 	baseTelegram
 }
 
-func (t *directTelegram) Dial(connOpts *mtproto.ConnectionOpts) (wrappers.ReadWriteCloserWithAddr, error) {
+func (t *DirectTelegram) Dial(connID string, connOpts *mtproto.ConnectionOpts) (wrappers.StreamReadWriteCloser, error) {
 	dc := connOpts.DC
 	if dc < 0 {
 		dc = -dc
@@ -41,23 +40,23 @@ func (t *directTelegram) Dial(connOpts *mtproto.ConnectionOpts) (wrappers.ReadWr
 		dc = 1
 	}
 
-	return t.baseTelegram.dial(dc-1, connOpts.ConnectionProto)
+	return t.baseTelegram.dial(dc-1, connID, connOpts.ConnectionProto)
 }
 
-func (t *directTelegram) Init(connOpts *mtproto.ConnectionOpts, conn wrappers.ReadWriteCloserWithAddr) (wrappers.ReadWriteCloserWithAddr, error) {
+func (t *DirectTelegram) Init(connOpts *mtproto.ConnectionOpts, conn wrappers.StreamReadWriteCloser) (wrappers.Wrap, error) {
 	obfs2, frame := obfuscated2.MakeTelegramObfuscated2Frame(connOpts)
 
-	if n, err := conn.Write(frame); err != nil || n != obfuscated2.FrameLen {
+	if _, err := conn.Write(frame); err != nil {
 		return nil, errors.Annotate(err, "Cannot write hadnshake frame")
 	}
 
-	return wrappers.NewStreamCipherRWC(conn, obfs2.Encryptor, obfs2.Decryptor), nil
+	return wrappers.NewStreamCipher(conn, obfs2.Encryptor, obfs2.Decryptor), nil
 }
 
 // NewDirectTelegram returns Telegram instance which connects directly
 // to Telegram bypassing middleproxies.
-func NewDirectTelegram(conf *config.Config, _ *zap.SugaredLogger) Telegram {
-	return &directTelegram{baseTelegram{
+func NewDirectTelegram(conf *config.Config) Telegram {
+	return &DirectTelegram{baseTelegram{
 		dialer: tgDialer{
 			Dialer: net.Dialer{Timeout: telegramDialTimeout},
 			conf:   conf,

telegram/middle.go

@@ -1,56 +1,26 @@
 package telegram
 
 import (
-	"fmt"
-	"io"
 	"net"
 	"net/http"
 	"sync"
 
 	"github.com/juju/errors"
-	"go.uber.org/zap"
 
 	"github.com/9seconds/mtg/config"
 	"github.com/9seconds/mtg/mtproto"
 	"github.com/9seconds/mtg/mtproto/rpc"
-	mtwrappers "github.com/9seconds/mtg/mtproto/wrappers"
 	"github.com/9seconds/mtg/wrappers"
 )
 
-type middleTelegram struct {
+type MiddleTelegram struct {
 	middleTelegramCaller
 
 	conf *config.Config
 }
 
-func NewMiddleTelegram(conf *config.Config, logger *zap.SugaredLogger) Telegram {
-	tg := &middleTelegram{
-		middleTelegramCaller: middleTelegramCaller{
-			baseTelegram: baseTelegram{
-				dialer: tgDialer{
-					Dialer: net.Dialer{Timeout: telegramDialTimeout},
-					conf:   conf,
-				},
-			},
-			logger: logger,
-			httpClient: &http.Client{
-				Timeout: middleTelegramHTTPClientTimeout,
-			},
-			dialerMutex: &sync.RWMutex{},
-		},
-		conf: conf,
-	}
-
-	if err := tg.update(); err != nil {
-		panic(err)
-	}
-	go tg.autoUpdate()
-
-	return tg
-}
-
-func (t *middleTelegram) Init(connOpts *mtproto.ConnectionOpts, conn wrappers.ReadWriteCloserWithAddr) (wrappers.ReadWriteCloserWithAddr, error) {
-	rpcNonceConn := mtwrappers.NewFrameRWC(conn, rpc.RPCNonceSeqNo)
+func (t *MiddleTelegram) Init(connOpts *mtproto.ConnectionOpts, conn wrappers.StreamReadWriteCloser) (wrappers.Wrap, error) {
+	rpcNonceConn := wrappers.NewMTProtoFrame(conn, rpc.SeqNoNonce)
 
 	rpcNonceReq, err := t.sendRPCNonceRequest(rpcNonceConn)
 	if err != nil {
@@ -61,23 +31,29 @@ func (t *middleTelegram) Init(connOpts *mtproto.ConnectionOpts, conn wrappers.Re
 		return nil, err
 	}
 
-	secureConn := mtwrappers.NewMiddleProxyCipherRWC(conn, rpcNonceReq, rpcNonceResp, t.proxySecret)
-	secureConn = mtwrappers.NewFrameRWC(secureConn, rpc.RPCHandshakeSeqNo)
+	secureConn := wrappers.NewMiddleProxyCipher(conn, rpcNonceReq, rpcNonceResp, t.proxySecret)
+	frameConn := wrappers.NewMTProtoFrame(secureConn, rpc.SeqNoHandshake)
 
-	rpcHandshakeReq, err := t.sendRPCHandshakeRequest(secureConn)
+	rpcHandshakeReq, err := t.sendRPCHandshakeRequest(frameConn)
+	if err != nil {
+		return nil, err
+	}
+	_, err = t.receiveRPCHandshakeResponse(frameConn, rpcHandshakeReq)
 	if err != nil {
 		return nil, err
 	}
-	_, err = t.receiveRPCHandshakeResponse(secureConn, rpcHandshakeReq)
+
+	proxyConn, err := wrappers.NewMTProtoProxy(frameConn, connOpts, t.conf.AdTag)
 	if err != nil {
 		return nil, err
 	}
+	proxyConn.Logger().Infow("Telegram connection initialized")
 
-	return mtwrappers.NewProxyRequestRWC(secureConn, connOpts, t.conf.AdTag)
+	return proxyConn, nil
 }
 
-func (t *middleTelegram) sendRPCNonceRequest(conn io.Writer) (*rpc.RPCNonceRequest, error) {
-	rpcNonceReq, err := rpc.NewRPCNonceRequest(t.proxySecret)
+func (t *MiddleTelegram) sendRPCNonceRequest(conn wrappers.PacketWriter) (*rpc.NonceRequest, error) {
+	rpcNonceReq, err := rpc.NewNonceRequest(t.proxySecret)
 	if err != nil {
 		return nil, errors.Annotate(err, "Cannot create RPC nonce request")
 	}
@@ -88,14 +64,13 @@ func (t *middleTelegram) sendRPCNonceRequest(conn io.Writer) (*rpc.RPCNonceReque
 	return rpcNonceReq, nil
 }
 
-func (t *middleTelegram) receiveRPCNonceResponse(conn io.Reader, req *rpc.RPCNonceRequest) (*rpc.RPCNonceResponse, error) {
-	var ans [128]byte
-
-	n, err := conn.Read(ans[:])
+func (t *MiddleTelegram) receiveRPCNonceResponse(conn wrappers.PacketReader, req *rpc.NonceRequest) (*rpc.NonceResponse, error) {
+	packet, err := conn.Read()
 	if err != nil {
 		return nil, errors.Annotate(err, "Cannot read RPC nonce response")
 	}
-	rpcNonceResp, err := rpc.NewRPCNonceResponse(ans[:n])
+
+	rpcNonceResp, err := rpc.NewNonceResponse(packet)
 	if err != nil {
 		return nil, errors.Annotate(err, "Cannot initialize RPC nonce response")
 	}
@@ -106,8 +81,8 @@ func (t *middleTelegram) receiveRPCNonceResponse(conn io.Reader, req *rpc.RPCNon
 	return rpcNonceResp, nil
 }
 
-func (t *middleTelegram) sendRPCHandshakeRequest(conn io.Writer) (*rpc.RPCHandshakeRequest, error) {
-	req := rpc.NewRPCHandshakeRequest()
+func (t *MiddleTelegram) sendRPCHandshakeRequest(conn wrappers.PacketWriter) (*rpc.HandshakeRequest, error) {
+	req := rpc.NewHandshakeRequest()
 	if _, err := conn.Write(req.Bytes()); err != nil {
 		return nil, errors.Annotate(err, "Cannot send RPC handshake request")
 	}
@@ -115,21 +90,44 @@ func (t *middleTelegram) sendRPCHandshakeRequest(conn io.Writer) (*rpc.RPCHandsh
 	return req, nil
 }
 
-func (t *middleTelegram) receiveRPCHandshakeResponse(conn io.Reader, req *rpc.RPCHandshakeRequest) (*rpc.RPCHandshakeResponse, error) {
-	var ans [128]byte
-
-	n, err := conn.Read(ans[:])
+func (t *MiddleTelegram) receiveRPCHandshakeResponse(conn wrappers.PacketReader, req *rpc.HandshakeRequest) (*rpc.HandshakeResponse, error) {
+	packet, err := conn.Read()
 	if err != nil {
 		return nil, errors.Annotate(err, "Cannot read RPC handshake response")
 	}
-	rpcHandshakeResp, err := rpc.NewRPCHandshakeResponse(ans[:n])
+
+	rpcHandshakeResp, err := rpc.NewHandshakeResponse(packet)
 	if err != nil {
 		return nil, errors.Annotate(err, "Cannot initialize RPC handshake response")
 	}
 	if err = rpcHandshakeResp.Valid(req); err != nil {
 		return nil, errors.Annotate(err, "Invalid RPC handshake response")
 	}
-	fmt.Println("VICTORY")
 
 	return rpcHandshakeResp, nil
 }
+
+func NewMiddleTelegram(conf *config.Config) Telegram {
+	tg := &MiddleTelegram{
+		middleTelegramCaller: middleTelegramCaller{
+			baseTelegram: baseTelegram{
+				dialer: tgDialer{
+					Dialer: net.Dialer{Timeout: telegramDialTimeout},
+					conf:   conf,
+				},
+			},
+			httpClient: &http.Client{
+				Timeout: middleTelegramHTTPClientTimeout,
+			},
+			dialerMutex: &sync.RWMutex{},
+		},
+		conf: conf,
+	}
+
+	if err := tg.update(); err != nil {
+		panic(err)
+	}
+	go tg.autoUpdate()
+
+	return tg
+}

telegram/middle_caller.go

@@ -28,18 +28,17 @@ const (
 	tgUserAgent       = "mtg"
 )
 
-var middleTelegramProxyConfigSplitter *regexp.Regexp
+var middleTelegramProxyConfigSplitter = regexp.MustCompile(`\s+`)
 
 type middleTelegramCaller struct {
 	baseTelegram
 
 	proxySecret []byte
 	dialerMutex *sync.RWMutex
-	logger      *zap.SugaredLogger
 	httpClient  *http.Client
 }
 
-func (t *middleTelegramCaller) Dial(connOpts *mtproto.ConnectionOpts) (wrappers.ReadWriteCloserWithAddr, error) {
+func (t *middleTelegramCaller) Dial(connID string, connOpts *mtproto.ConnectionOpts) (wrappers.StreamReadWriteCloser, error) {
 	dc := connOpts.DC
 	if dc == 0 {
 		dc = 1
@@ -47,13 +46,13 @@ func (t *middleTelegramCaller) Dial(connOpts *mtproto.ConnectionOpts) (wrappers.
 	t.dialerMutex.RLock()
 	defer t.dialerMutex.RUnlock()
 
-	return t.baseTelegram.dial(dc, connOpts.ConnectionProto)
+	return t.baseTelegram.dial(dc, connID, connOpts.ConnectionProto)
 }
 
 func (t *middleTelegramCaller) autoUpdate() {
 	for range time.Tick(middleTelegramAutoUpdateInterval) {
 		if err := t.update(); err != nil {
-			t.logger.Warnw("Cannot update from Telegram", "error", err)
+			zap.S().Warnw("Cannot update from Telegram", "error", err)
 		}
 	}
 }
@@ -80,7 +79,7 @@ func (t *middleTelegramCaller) update() error {
 	t.v6Addresses = v6Addresses
 	t.dialerMutex.Unlock()
 
-	t.logger.Infow("Telegram middle proxy data has been updated")
+	zap.S().Infow("Telegram middle proxy data has been updated")
 
 	return nil
 }
@@ -151,7 +150,3 @@ func (t *middleTelegramCaller) call(url string) (*http.Response, error) {
 
 	return t.httpClient.Do(req)
 }
-
-func init() {
-	middleTelegramProxyConfigSplitter = regexp.MustCompile(`\s+`)
-}

telegram/telegram.go

@@ -9,12 +9,9 @@ import (
 	"github.com/9seconds/mtg/wrappers"
 )
 
-// Telegram defines an interface to connect to Telegram. This
-// encapsulates logic of working with middleproxies or direct
-// connections.
 type Telegram interface {
-	Dial(*mtproto.ConnectionOpts) (wrappers.ReadWriteCloserWithAddr, error)
-	Init(*mtproto.ConnectionOpts, wrappers.ReadWriteCloserWithAddr) (wrappers.ReadWriteCloserWithAddr, error)
+	Dial(string, *mtproto.ConnectionOpts) (wrappers.StreamReadWriteCloser, error)
+	Init(*mtproto.ConnectionOpts, wrappers.StreamReadWriteCloser) (wrappers.Wrap, error)
 }
 
 type baseTelegram struct {
@@ -24,7 +21,7 @@ type baseTelegram struct {
 	v6Addresses map[int16][]string
 }
 
-func (b *baseTelegram) dial(dcIdx int16, proto mtproto.ConnectionProtocol) (wrappers.ReadWriteCloserWithAddr, error) {
+func (b *baseTelegram) dial(dcIdx int16, connID string, proto mtproto.ConnectionProtocol) (wrappers.StreamReadWriteCloser, error) {
 	addrs := make([]string, 2)
 
 	if proto&mtproto.ConnectionProtocolIPv6 != 0 {
@@ -39,7 +36,7 @@ func (b *baseTelegram) dial(dcIdx int16, proto mtproto.ConnectionProtocol) (wrap
 	}
 
 	for _, addr := range addrs {
-		if conn, err := b.dialer.dialRWC(addr); err == nil {
+		if conn, err := b.dialer.dialRWC(addr, connID); err == nil {
 			return conn, err
 		}
 	}

utils/read_current_data.go

@@ -0,0 +1,20 @@
+package utils
+
+import "io"
+
+const readCurrentDataBufferSize = 1024 + 1 // + 1 because telegram operates with blocks mod 4
+
+func ReadCurrentData(src io.Reader) (rv []byte, err error) {
+	buf := make([]byte, readCurrentDataBufferSize)
+	n := readCurrentDataBufferSize
+
+	for n == len(buf) {
+		n, err = src.Read(buf)
+		if err != nil {
+			return nil, err
+		}
+		rv = append(rv, buf[:n]...)
+	}
+
+	return rv, nil
+}

utils/reverse_bytes.go

@@ -0,0 +1,14 @@
+package utils
+
+func ReverseBytes(data []byte) []byte {
+	dataLen := len(data)
+	rv := make([]byte, dataLen)
+
+	rv[dataLen/2] = data[dataLen/2]
+	for i := dataLen/2 - 1; i >= 0; i-- {
+		opp := dataLen - i - 1
+		rv[i], rv[opp] = data[opp], data[i]
+	}
+
+	return rv
+}

utils/uint24.go

@@ -0,0 +1,11 @@
+package utils
+
+type Uint24 [3]byte
+
+func ToUint24(number uint32) Uint24 {
+	return Uint24{byte(number), byte(number >> 8), byte(number >> 16)}
+}
+
+func FromUint24(number Uint24) uint32 {
+	return uint32(number[0]) + (uint32(number[1]) << 8) + (uint32(number[2]) << 16)
+}

wrappers/blockcipher.go

@@ -0,0 +1,90 @@
+package wrappers
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"net"
+
+	"go.uber.org/zap"
+
+	"github.com/9seconds/mtg/utils"
+	"github.com/juju/errors"
+)
+
+type BlockCipher struct {
+	buf *bytes.Buffer
+
+	logger    *zap.SugaredLogger
+	conn      StreamReadWriteCloser
+	encryptor cipher.BlockMode
+	decryptor cipher.BlockMode
+}
+
+func (b *BlockCipher) Read(p []byte) (int, error) {
+	if b.buf.Len() > 0 {
+		return b.flush(p)
+	}
+
+	buf := []byte{}
+	for len(buf) == 0 || len(buf)%aes.BlockSize != 0 {
+		rv, err := utils.ReadCurrentData(b.conn)
+		if err != nil {
+			return 0, errors.Annotate(err, "Cannot read from socket")
+		}
+		buf = append(buf, rv...)
+	}
+
+	b.decryptor.CryptBlocks(buf, buf)
+	b.buf.Write(buf)
+
+	return b.flush(p)
+}
+
+func (b *BlockCipher) flush(p []byte) (int, error) {
+	if b.buf.Len() <= len(p) {
+		sizeToReturn := b.buf.Len()
+		copy(p, b.buf.Bytes())
+		b.buf.Reset()
+		return sizeToReturn, nil
+	}
+
+	return b.buf.Read(p)
+}
+
+func (b *BlockCipher) Write(p []byte) (int, error) {
+	if len(p)%aes.BlockSize > 0 {
+		return 0, errors.Errorf("Incorrect block size %d", len(p))
+	}
+
+	encrypted := make([]byte, len(p))
+	b.encryptor.CryptBlocks(encrypted, p)
+
+	return b.conn.Write(encrypted)
+}
+
+func (b *BlockCipher) Logger() *zap.SugaredLogger {
+	return b.logger
+}
+
+func (b *BlockCipher) LocalAddr() *net.TCPAddr {
+	return b.conn.LocalAddr()
+}
+
+func (b *BlockCipher) RemoteAddr() *net.TCPAddr {
+	return b.conn.RemoteAddr()
+}
+
+func (b *BlockCipher) Close() error {
+	return b.conn.Close()
+}
+
+func NewBlockCipher(conn StreamReadWriteCloser, encryptor, decryptor cipher.BlockMode) StreamReadWriteCloser {
+	return &BlockCipher{
+		buf:       &bytes.Buffer{},
+		conn:      conn,
+		logger:    conn.Logger().Named("block-cipher"),
+		encryptor: encryptor,
+		decryptor: decryptor,
+	}
+}

wrappers/blockcipherrwc.go

@@ -1,66 +0,0 @@
-package wrappers
-
-import (
-	"crypto/aes"
-	"crypto/cipher"
-	"net"
-
-	"github.com/juju/errors"
-)
-
-type BlockCipherReadWriteCloserWithAddr struct {
-	BufferedReader
-
-	conn      ReadWriteCloserWithAddr
-	encryptor cipher.BlockMode
-	decryptor cipher.BlockMode
-}
-
-func (c *BlockCipherReadWriteCloserWithAddr) Read(p []byte) (int, error) {
-	return c.BufferedRead(p, func() error {
-		bufferLength := c.Buffer.Len()
-		for bufferLength%aes.BlockSize != 0 || bufferLength == 0 {
-			n, err := c.conn.Read(p)
-			if err != nil {
-				return errors.Annotate(err, "Cannot read from socket")
-			}
-			c.Buffer.Write(p[:n])
-			bufferLength = c.Buffer.Len()
-		}
-		c.decryptor.CryptBlocks(c.Buffer.Bytes(), c.Buffer.Bytes())
-
-		return nil
-	})
-}
-
-func (c *BlockCipherReadWriteCloserWithAddr) Write(p []byte) (int, error) {
-	if len(p)%aes.BlockSize > 0 {
-		return 0, errors.Errorf("Incorrect block size %d", len(p))
-	}
-
-	encrypted := make([]byte, len(p))
-	c.encryptor.CryptBlocks(encrypted, p)
-
-	return c.conn.Write(encrypted)
-}
-
-func (c *BlockCipherReadWriteCloserWithAddr) Close() error {
-	return c.conn.Close()
-}
-
-func (c *BlockCipherReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return c.conn.LocalAddr()
-}
-
-func (c *BlockCipherReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return c.conn.RemoteAddr()
-}
-
-func NewBlockCipherRWC(conn ReadWriteCloserWithAddr, encryptor, decryptor cipher.BlockMode) ReadWriteCloserWithAddr {
-	return &BlockCipherReadWriteCloserWithAddr{
-		BufferedReader: NewBufferedReader(),
-		conn:           conn,
-		encryptor:      encryptor,
-		decryptor:      decryptor,
-	}
-}

wrappers/buffer_pool.go

@@ -1,27 +0,0 @@
-package wrappers
-
-import (
-	"bytes"
-	"sync"
-)
-
-var bufPool sync.Pool
-
-func getBuffer() *bytes.Buffer {
-	buf := bufPool.Get().(*bytes.Buffer)
-	buf.Reset()
-
-	return buf
-}
-
-func putBuffer(buf *bytes.Buffer) {
-	bufPool.Put(buf)
-}
-
-func init() {
-	bufPool = sync.Pool{
-		New: func() interface{} {
-			return &bytes.Buffer{}
-		},
-	}
-}

wrappers/buffered_reader.go

@@ -1,32 +0,0 @@
-package wrappers
-
-import "bytes"
-
-type BufferedReader struct {
-	Buffer *bytes.Buffer
-}
-
-func (b *BufferedReader) BufferedRead(p []byte, callback func() error) (int, error) {
-	if b.Buffer.Len() > 0 {
-		return b.flush(p)
-	}
-	if err := callback(); err != nil {
-		return 0, err
-	}
-	return b.flush(p)
-}
-
-func (b *BufferedReader) flush(p []byte) (int, error) {
-	if b.Buffer.Len() < len(p) {
-		sizeToReturn := b.Buffer.Len()
-		copy(p, b.Buffer.Bytes())
-		b.Buffer.Reset()
-		return sizeToReturn, nil
-	}
-
-	return b.Buffer.Read(p)
-}
-
-func NewBufferedReader() BufferedReader {
-	return BufferedReader{Buffer: &bytes.Buffer{}}
-}

wrappers/conn.go

@@ -0,0 +1,105 @@
+package wrappers
+
+import (
+	"net"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+type ConnPurpose uint8
+
+func (c ConnPurpose) String() string {
+	switch c {
+	case ConnPurposeClient:
+		return "client"
+	case ConnPurposeTelegram:
+		return "telegram"
+	}
+
+	return ""
+}
+
+const (
+	ConnPurposeClient = iota
+	ConnPurposeTelegram
+)
+
+const (
+	connTimeoutRead  = 5 * time.Minute
+	connTimeoutWrite = 5 * time.Minute
+)
+
+type Conn struct {
+	connID     string
+	conn       net.Conn
+	logger     *zap.SugaredLogger
+	publicIPv4 net.IP
+	publicIPv6 net.IP
+}
+
+func (c *Conn) Write(p []byte) (int, error) {
+	c.conn.SetWriteDeadline(time.Now().Add(connTimeoutWrite))
+	n, err := c.conn.Write(p)
+
+	c.logger.Debugw("Write to stream", "bytes", n, "error", err)
+
+	return n, err
+}
+
+func (c *Conn) Read(p []byte) (int, error) {
+	c.conn.SetReadDeadline(time.Now().Add(connTimeoutRead))
+	n, err := c.conn.Read(p)
+
+	c.logger.Debugw("Read from stream", "bytes", n, "error", err)
+
+	return n, err
+}
+
+func (c *Conn) Close() error {
+	defer c.logger.Debugw("Closed connection")
+	return c.conn.Close()
+}
+
+func (c *Conn) LocalAddr() *net.TCPAddr {
+	addr := c.conn.LocalAddr().(*net.TCPAddr)
+	newAddr := *addr
+
+	if c.RemoteAddr().IP.To4() != nil {
+		if c.publicIPv4 != nil {
+			newAddr.IP = c.publicIPv4
+		}
+	} else if c.publicIPv6 != nil {
+		newAddr.IP = c.publicIPv6
+	}
+
+	return &newAddr
+}
+
+func (c *Conn) RemoteAddr() *net.TCPAddr {
+	return c.conn.RemoteAddr().(*net.TCPAddr)
+}
+
+func (c *Conn) Logger() *zap.SugaredLogger {
+	return c.logger
+}
+
+func NewConn(conn net.Conn, connID string, purpose ConnPurpose, publicIPv4, publicIPv6 net.IP) StreamReadWriteCloser {
+	logger := zap.S().With(
+		"connection_id", connID,
+		"local_address", conn.LocalAddr(),
+		"remote_address", conn.RemoteAddr(),
+		"purpose", purpose,
+	).Named("conn")
+
+	wrapper := Conn{
+		logger:     logger,
+		connID:     connID,
+		conn:       conn,
+		publicIPv4: publicIPv4,
+		publicIPv6: publicIPv6,
+	}
+	wrapper.logger = logger.With("faked_local_addr", wrapper.LocalAddr())
+
+	return &wrapper
+}

wrappers/ctxrwc.go

@@ -1,67 +0,0 @@
-package wrappers
-
-import (
-	"context"
-	"net"
-
-	"github.com/juju/errors"
-)
-
-// CtxReadWriteCloser wraps underlying connection and does management of the
-// context and its cancel function.
-type CtxReadWriteCloserWithAddr struct {
-	ctx    context.Context
-	conn   ReadWriteCloserWithAddr
-	cancel context.CancelFunc
-}
-
-// Read reads from connection
-func (c *CtxReadWriteCloserWithAddr) Read(p []byte) (int, error) {
-	select {
-	case <-c.ctx.Done():
-		return 0, errors.Annotate(c.ctx.Err(), "Read is failed because of closed context")
-	default:
-		n, err := c.conn.Read(p)
-		if err != nil {
-			c.cancel()
-		}
-		return n, err
-	}
-}
-
-// Write writes into connection.
-func (c *CtxReadWriteCloserWithAddr) Write(p []byte) (int, error) {
-	select {
-	case <-c.ctx.Done():
-		return 0, errors.Annotate(c.ctx.Err(), "Write is failed because of closed context")
-	default:
-		n, err := c.conn.Write(p)
-		if err != nil {
-			c.cancel()
-		}
-		return n, err
-	}
-}
-
-// Close closes underlying connection.
-func (c *CtxReadWriteCloserWithAddr) Close() error {
-	return c.conn.Close()
-}
-
-func (c *CtxReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return c.conn.LocalAddr()
-}
-
-func (c *CtxReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return c.conn.RemoteAddr()
-}
-
-// NewCtxRWC returns ReadWriteCloser which respects given context,
-// cancellation etc.
-func NewCtxRWC(ctx context.Context, cancel context.CancelFunc, conn ReadWriteCloserWithAddr) ReadWriteCloserWithAddr {
-	return &CtxReadWriteCloserWithAddr{
-		conn:   conn,
-		ctx:    ctx,
-		cancel: cancel,
-	}
-}

wrappers/logrwc.go

@@ -1,55 +0,0 @@
-package wrappers
-
-import (
-	"net"
-
-	"go.uber.org/zap"
-)
-
-// LogReadWriteCloser adds additional logging for reading/writing. All
-// logging is performed for debug mode only.
-type LogReadWriteCloserWithAddr struct {
-	conn   ReadWriteCloserWithAddr
-	logger *zap.SugaredLogger
-	sockid string
-	name   string
-}
-
-// Read reads from connection
-func (l *LogReadWriteCloserWithAddr) Read(p []byte) (n int, err error) {
-	n, err = l.conn.Read(p)
-	l.logger.Debugw("Finish reading", "name", l.name, "socketid", l.sockid, "nbytes", n, "error", err)
-	return
-}
-
-// Write writes into connection.
-func (l *LogReadWriteCloserWithAddr) Write(p []byte) (n int, err error) {
-	n, err = l.conn.Write(p)
-	l.logger.Debugw("Finish writing", "name", l.name, "socketid", l.sockid, "nbytes", n, "error", err)
-	return
-}
-
-// Close closes underlying connection.
-func (l *LogReadWriteCloserWithAddr) Close() error {
-	err := l.conn.Close()
-	l.logger.Debugw("Finish closing socket", "name", l.name, "socketid", l.sockid, "error", err)
-	return err
-}
-
-func (l *LogReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return l.conn.LocalAddr()
-}
-
-func (l *LogReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return l.conn.RemoteAddr()
-}
-
-// NewLogRWC wraps ReadWriteCloser with logger calls.
-func NewLogRWC(conn ReadWriteCloserWithAddr, logger *zap.SugaredLogger, sockid string, name string) ReadWriteCloserWithAddr {
-	return &LogReadWriteCloserWithAddr{
-		conn:   conn,
-		logger: logger,
-		sockid: sockid,
-		name:   name,
-	}
-}

wrappers/mtproto_abridged.go

@@ -0,0 +1,152 @@
+package wrappers
+
+import (
+	"bytes"
+	"io"
+	"net"
+
+	"github.com/juju/errors"
+	"go.uber.org/zap"
+
+	"github.com/9seconds/mtg/mtproto"
+	"github.com/9seconds/mtg/utils"
+)
+
+const (
+	mtprotoAbridgedSmallPacketLength = 0x7f
+	mtprotoAbridgedQuickAckLength    = 0x80
+	mtprotoAbridgedLargePacketLength = 16777216 // 256 ^ 3
+)
+
+type MTProtoAbridged struct {
+	conn   StreamReadWriteCloser
+	opts   *mtproto.ConnectionOpts
+	logger *zap.SugaredLogger
+
+	readCounter  uint32
+	writeCounter uint32
+}
+
+func (m *MTProtoAbridged) Read() ([]byte, error) {
+	defer func() {
+		m.readCounter++
+	}()
+
+	m.logger.Debugw("Read packet",
+		"simple_ack", m.opts.ReadHacks.SimpleAck,
+		"quick_ack", m.opts.ReadHacks.QuickAck,
+		"counter", m.readCounter,
+	)
+
+	buf := &bytes.Buffer{}
+	buf.Grow(3)
+
+	if _, err := io.CopyN(buf, m.conn, 1); err != nil {
+		return nil, errors.Annotate(err, "Cannot read message length")
+	}
+	msgLength := uint32(buf.Bytes()[0])
+	buf.Reset()
+
+	m.logger.Debugw("Packet first byte",
+		"byte", msgLength,
+		"counter", m.readCounter,
+		"simple_ack", m.opts.ReadHacks.SimpleAck,
+		"quick_ack", m.opts.ReadHacks.QuickAck,
+	)
+
+	if msgLength >= mtprotoAbridgedQuickAckLength {
+		m.opts.ReadHacks.QuickAck = true
+		msgLength -= mtprotoAbridgedQuickAckLength
+	}
+
+	if msgLength == mtprotoAbridgedSmallPacketLength {
+		if _, err := io.CopyN(buf, m.conn, 3); err != nil {
+			return nil, errors.Annotate(err, "Cannot read the correct message length")
+		}
+		number := utils.Uint24{}
+		copy(number[:], buf.Bytes())
+		msgLength = utils.FromUint24(number)
+	}
+	msgLength *= 4
+
+	m.logger.Debugw("Packet length",
+		"length", msgLength,
+		"simple_ack", m.opts.ReadHacks.SimpleAck,
+		"quick_ack", m.opts.ReadHacks.QuickAck,
+		"counter", m.readCounter,
+	)
+
+	buf.Reset()
+	buf.Grow(int(msgLength))
+	if _, err := io.CopyN(buf, m.conn, int64(msgLength)); err != nil {
+		return nil, errors.Annotate(err, "Cannot read message")
+	}
+
+	return buf.Bytes(), nil
+}
+
+func (m *MTProtoAbridged) Write(p []byte) (int, error) {
+	defer func() {
+		m.writeCounter++
+	}()
+
+	m.logger.Debugw("Write packet",
+		"length", len(p),
+		"simple_ack", m.opts.WriteHacks.SimpleAck,
+		"quick_ack", m.opts.WriteHacks.QuickAck,
+		"counter", m.writeCounter,
+	)
+
+	if len(p)%4 != 0 {
+		return 0, errors.Errorf("Incorrect packet length %d", len(p))
+	}
+
+	if m.opts.WriteHacks.SimpleAck {
+		return m.conn.Write(utils.ReverseBytes(p))
+	}
+
+	packetLength := len(p) / 4
+	switch {
+	case packetLength < mtprotoAbridgedSmallPacketLength:
+		newData := append([]byte{byte(packetLength)}, p...)
+		return m.conn.Write(newData)
+
+	case packetLength < mtprotoAbridgedLargePacketLength:
+		length24 := utils.ToUint24(uint32(packetLength))
+
+		buf := &bytes.Buffer{}
+		buf.Grow(1 + 3 + len(p))
+
+		buf.WriteByte(byte(mtprotoAbridgedSmallPacketLength))
+		buf.Write(length24[:])
+		buf.Write(p)
+
+		return m.conn.Write(buf.Bytes())
+	}
+
+	return 0, errors.Errorf("Packet is too big %d", len(p))
+}
+
+func (m *MTProtoAbridged) Logger() *zap.SugaredLogger {
+	return m.logger
+}
+
+func (m *MTProtoAbridged) LocalAddr() *net.TCPAddr {
+	return m.conn.LocalAddr()
+}
+
+func (m *MTProtoAbridged) RemoteAddr() *net.TCPAddr {
+	return m.conn.RemoteAddr()
+}
+
+func (m *MTProtoAbridged) Close() error {
+	return m.conn.Close()
+}
+
+func NewMTProtoAbridged(conn StreamReadWriteCloser, opts *mtproto.ConnectionOpts) PacketReadWriteCloser {
+	return &MTProtoAbridged{
+		conn:   conn,
+		opts:   opts,
+		logger: conn.Logger().Named("mtproto-abridged"),
+	}
+}

mtproto/wrappers/crypt.go → wrappers/mtproto_cipher.go

@@ -10,7 +10,7 @@ import (
 	"net"
 
 	"github.com/9seconds/mtg/mtproto/rpc"
-	"github.com/9seconds/mtg/wrappers"
+	"github.com/9seconds/mtg/utils"
 )
 
 type CipherPurpose uint8
@@ -22,21 +22,20 @@ const (
 
 var emptyIP = [4]byte{0x00, 0x00, 0x00, 0x00}
 
-func NewMiddleProxyCipherRWC(conn wrappers.ReadWriteCloserWithAddr, req *rpc.RPCNonceRequest, resp *rpc.RPCNonceResponse, secret []byte) wrappers.ReadWriteCloserWithAddr {
+func NewMiddleProxyCipher(conn StreamReadWriteCloser, req *rpc.NonceRequest, resp *rpc.NonceResponse, secret []byte) StreamReadWriteCloser {
 	localAddr := conn.LocalAddr()
 	remoteAddr := conn.RemoteAddr()
 
-	encKey, encIV := makeKeys(CipherPurposeClient, req, resp, localAddr, remoteAddr, secret)
-	decKey, decIV := makeKeys(CipherPurposeServer, req, resp, localAddr, remoteAddr, secret)
+	encKey, encIV := deriveKeys(CipherPurposeClient, req, resp, localAddr, remoteAddr, secret)
+	decKey, decIV := deriveKeys(CipherPurposeServer, req, resp, localAddr, remoteAddr, secret)
 
 	enc, _ := makeEncrypterDecrypter(encKey, encIV)
 	_, dec := makeEncrypterDecrypter(decKey, decIV)
 
-	return wrappers.NewBlockCipherRWC(conn, enc, dec)
+	return NewBlockCipher(conn, enc, dec)
 }
 
-func makeKeys(purpose CipherPurpose, req *rpc.RPCNonceRequest, resp *rpc.RPCNonceResponse,
-	client *net.TCPAddr, remote *net.TCPAddr, secret []byte) ([]byte, []byte) {
+func deriveKeys(purpose CipherPurpose, req *rpc.NonceRequest, resp *rpc.NonceResponse, client *net.TCPAddr, remote *net.TCPAddr, secret []byte) ([]byte, []byte) {
 	message := bytes.Buffer{}
 	message.Write(resp.Nonce[:])
 	message.Write(req.Nonce[:])
@@ -45,8 +44,8 @@ func makeKeys(purpose CipherPurpose, req *rpc.RPCNonceRequest, resp *rpc.RPCNonc
 	clientIPv4 := emptyIP[:]
 	serverIPv4 := emptyIP[:]
 	if client.IP.To4() != nil {
-		clientIPv4 = reverseBytes(client.IP.To4())
-		serverIPv4 = reverseBytes(remote.IP.To4())
+		clientIPv4 = utils.ReverseBytes(client.IP.To4())
+		serverIPv4 = utils.ReverseBytes(remote.IP.To4())
 	}
 	message.Write(serverIPv4)
 
@@ -93,16 +92,3 @@ func makeEncrypterDecrypter(key, iv []byte) (cipher.BlockMode, cipher.BlockMode)
 
 	return cipher.NewCBCEncrypter(block, iv), cipher.NewCBCDecrypter(block, iv)
 }
-
-func reverseBytes(data []byte) []byte {
-	dataLen := len(data)
-	rv := make([]byte, dataLen)
-
-	rv[dataLen/2] = data[dataLen/2]
-	for i := dataLen/2 - 1; i >= 0; i-- {
-		opp := dataLen - i - 1
-		rv[i], rv[opp] = data[opp], data[i]
-	}
-
-	return rv
-}

wrappers/mtproto_frame.go

@@ -0,0 +1,143 @@
+package wrappers
+
+import (
+	"bytes"
+	"crypto/aes"
+	"encoding/binary"
+	"hash/crc32"
+	"io"
+	"io/ioutil"
+	"net"
+
+	"github.com/juju/errors"
+	"go.uber.org/zap"
+)
+
+const (
+	mtprotoFrameMinMessageLength = 12
+	mtprotoFrameMaxMessageLength = 16777216
+)
+
+var mtprotoFramePadding = []byte{0x04, 0x00, 0x00, 0x00}
+
+type MTProtoFrame struct {
+	conn   StreamReadWriteCloser
+	logger *zap.SugaredLogger
+
+	readSeqNo  int32
+	writeSeqNo int32
+}
+
+func (m *MTProtoFrame) Read() ([]byte, error) {
+	buf := &bytes.Buffer{}
+	sum := crc32.NewIEEE()
+	writer := io.MultiWriter(buf, sum)
+
+	for {
+		buf.Reset()
+		sum.Reset()
+		if _, err := io.CopyN(writer, m.conn, 4); err != nil {
+			return nil, errors.Annotate(err, "Cannot read frame padding")
+		}
+		if !bytes.Equal(buf.Bytes(), mtprotoFramePadding) {
+			break
+		}
+	}
+
+	messageLength := binary.LittleEndian.Uint32(buf.Bytes())
+	m.logger.Debugw("Read MTProto frame",
+		"messageLength", messageLength,
+		"sequence_number", m.readSeqNo,
+	)
+	if messageLength%4 != 0 || messageLength < mtprotoFrameMinMessageLength || messageLength > mtprotoFrameMaxMessageLength {
+		return nil, errors.Errorf("Incorrect frame message length %d", messageLength)
+	}
+
+	buf.Reset()
+	buf.Grow(int(messageLength) - 4 - 4)
+	if _, err := io.CopyN(writer, m.conn, int64(messageLength)-4-4); err != nil {
+		return nil, errors.Annotate(err, "Cannot read the message frame")
+	}
+
+	var seqNo int32
+	binary.Read(buf, binary.LittleEndian, &seqNo)
+	if seqNo != m.readSeqNo {
+		return nil, errors.Errorf("Unexpected sequence number %d (wait for %d)", seqNo, m.readSeqNo)
+	}
+
+	data, _ := ioutil.ReadAll(buf)
+	buf.Reset()
+	// write to buf, not to writer. This is because we are going to fetch
+	// crc32 checksum.
+	if _, err := io.CopyN(buf, m.conn, 4); err != nil {
+		return nil, errors.Annotate(err, "Cannot read checksum")
+	}
+
+	checksum := binary.LittleEndian.Uint32(buf.Bytes())
+	if checksum != sum.Sum32() {
+		return nil, errors.Errorf("CRC32 checksum mismatch. Wait for %d, got %d", sum.Sum32(), checksum)
+	}
+
+	m.logger.Debugw("Read MTProto frame",
+		"messageLength", messageLength,
+		"sequence_number", m.readSeqNo,
+		"dataLength", len(data),
+		"checksum", checksum,
+	)
+	m.readSeqNo++
+
+	return data, nil
+}
+
+func (m *MTProtoFrame) Write(p []byte) (int, error) {
+	messageLength := 4 + 4 + len(p) + 4
+	paddingLength := (aes.BlockSize - messageLength%aes.BlockSize) % aes.BlockSize
+
+	buf := &bytes.Buffer{}
+	buf.Grow(messageLength + paddingLength)
+
+	binary.Write(buf, binary.LittleEndian, uint32(messageLength))
+	binary.Write(buf, binary.LittleEndian, m.writeSeqNo)
+	buf.Write(p)
+
+	checksum := crc32.ChecksumIEEE(buf.Bytes())
+	binary.Write(buf, binary.LittleEndian, checksum)
+	buf.Write(bytes.Repeat(mtprotoFramePadding, paddingLength/4))
+
+	m.logger.Debugw("Write MTProto frame",
+		"length", len(p),
+		"sequence_number", m.writeSeqNo,
+		"crc32", checksum,
+		"frame_length", buf.Len(),
+	)
+	m.writeSeqNo++
+
+	_, err := m.conn.Write(buf.Bytes())
+
+	return len(p), err
+}
+
+func (m *MTProtoFrame) Logger() *zap.SugaredLogger {
+	return m.logger
+}
+
+func (m *MTProtoFrame) LocalAddr() *net.TCPAddr {
+	return m.conn.LocalAddr()
+}
+
+func (m *MTProtoFrame) RemoteAddr() *net.TCPAddr {
+	return m.conn.RemoteAddr()
+}
+
+func (m *MTProtoFrame) Close() error {
+	return m.conn.Close()
+}
+
+func NewMTProtoFrame(conn StreamReadWriteCloser, seqNo int32) PacketReadWriteCloser {
+	return &MTProtoFrame{
+		conn:       conn,
+		logger:     conn.Logger().Named("mtproto-frame"),
+		readSeqNo:  seqNo,
+		writeSeqNo: seqNo,
+	}
+}

wrappers/mtproto_intermediate.go

@@ -0,0 +1,113 @@
+package wrappers
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"net"
+
+	"github.com/juju/errors"
+	"go.uber.org/zap"
+
+	"github.com/9seconds/mtg/mtproto"
+)
+
+const mtprotoIntermediateQuickAckLength = 0x80000000
+
+type MTProtoIntermediate struct {
+	conn   StreamReadWriteCloser
+	opts   *mtproto.ConnectionOpts
+	logger *zap.SugaredLogger
+
+	readCounter  uint32
+	writeCounter uint32
+}
+
+func (m *MTProtoIntermediate) Read() ([]byte, error) {
+	defer func() {
+		m.readCounter++
+	}()
+
+	m.logger.Debugw("Read packet",
+		"simple_ack", m.opts.ReadHacks.SimpleAck,
+		"quick_ack", m.opts.ReadHacks.QuickAck,
+		"counter", m.readCounter,
+	)
+
+	buf := &bytes.Buffer{}
+	buf.Grow(4)
+
+	if _, err := io.CopyN(buf, m.conn, 4); err != nil {
+		return nil, errors.Annotate(err, "Cannot read message length")
+	}
+	length := binary.LittleEndian.Uint32(buf.Bytes())
+
+	m.logger.Debugw("Packet message length",
+		"simple_ack", m.opts.ReadHacks.SimpleAck,
+		"quick_ack", m.opts.ReadHacks.QuickAck,
+		"counter", m.readCounter,
+		"length", length,
+	)
+
+	if length > mtprotoIntermediateQuickAckLength {
+		m.opts.ReadHacks.QuickAck = true
+		length -= mtprotoIntermediateQuickAckLength
+	}
+
+	buf.Reset()
+	buf.Grow(int(length))
+	if _, err := io.CopyN(buf, m.conn, int64(length)); err != nil {
+		return nil, errors.Annotate(err, "Cannot read the message")
+	}
+
+	if length%4 != 0 {
+		length -= length % 4
+	}
+
+	return buf.Bytes()[:length], nil
+}
+
+func (m *MTProtoIntermediate) Write(p []byte) (int, error) {
+	defer func() {
+		m.writeCounter++
+	}()
+
+	m.logger.Debugw("Write packet",
+		"simple_ack", m.opts.WriteHacks.SimpleAck,
+		"quick_ack", m.opts.WriteHacks.QuickAck,
+		"counter", m.writeCounter,
+	)
+
+	if m.opts.ReadHacks.SimpleAck {
+		return m.conn.Write(p)
+	}
+
+	var length [4]byte
+	binary.LittleEndian.PutUint32(length[:], uint32(len(p)))
+
+	return m.conn.Write(append(length[:], p...))
+}
+
+func (m *MTProtoIntermediate) Logger() *zap.SugaredLogger {
+	return m.logger
+}
+
+func (m *MTProtoIntermediate) LocalAddr() *net.TCPAddr {
+	return m.conn.LocalAddr()
+}
+
+func (m *MTProtoIntermediate) RemoteAddr() *net.TCPAddr {
+	return m.conn.RemoteAddr()
+}
+
+func (m *MTProtoIntermediate) Close() error {
+	return m.conn.Close()
+}
+
+func NewMTProtoIntermediate(conn StreamReadWriteCloser, opts *mtproto.ConnectionOpts) PacketReadWriteCloser {
+	return &MTProtoIntermediate{
+		conn:   conn,
+		logger: conn.Logger().Named("mtproto-intermediate"),
+		opts:   opts,
+	}
+}

wrappers/mtproto_proxy.go

@@ -0,0 +1,158 @@
+package wrappers
+
+import (
+	"bytes"
+	"fmt"
+	"net"
+
+	"github.com/juju/errors"
+	"go.uber.org/zap"
+
+	"github.com/9seconds/mtg/mtproto"
+	"github.com/9seconds/mtg/mtproto/rpc"
+)
+
+type MTProtoProxy struct {
+	conn   PacketReadWriteCloser
+	req    *rpc.ProxyRequest
+	logger *zap.SugaredLogger
+
+	readCounter  uint32
+	writeCounter uint32
+}
+
+func (m *MTProtoProxy) Read() ([]byte, error) {
+	defer func() {
+		m.readCounter++
+	}()
+
+	m.logger.Debugw("Read packet",
+		"counter", m.readCounter,
+		"simple_ack", m.req.Options.WriteHacks.SimpleAck,
+		"quick_ack", m.req.Options.WriteHacks.QuickAck,
+	)
+
+	packet, err := m.conn.Read()
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot read packet")
+	}
+
+	m.logger.Debugw("Read packet length",
+		"counter", m.readCounter,
+		"simple_ack", m.req.Options.WriteHacks.SimpleAck,
+		"quick_ack", m.req.Options.WriteHacks.QuickAck,
+		"length", len(packet),
+	)
+
+	if len(packet) < 4 {
+		return nil, errors.Annotate(err, "Incorrect packet length")
+	}
+
+	tag, packet := packet[:4], packet[4:]
+	switch {
+	case bytes.Equal(tag, rpc.TagProxyAns):
+		return m.readProxyAns(packet)
+	case bytes.Equal(tag, rpc.TagSimpleAck):
+		return m.readSimpleAck(packet)
+	case bytes.Equal(tag, rpc.TagCloseExt):
+		return m.readCloseExt(packet)
+	}
+
+	return nil, errors.Errorf("Unknown RPC answer %v", tag)
+}
+
+func (m *MTProtoProxy) readProxyAns(data []byte) ([]byte, error) {
+	if len(data) < 12 {
+		return nil, errors.Errorf("Incorrect data of proxy answer: %d", len(data))
+	}
+	data = data[12:]
+
+	m.logger.Debugw("Read RPC_PROXY_ANS",
+		"counter", m.readCounter,
+		"length", len(data),
+	)
+
+	return data, nil
+}
+
+func (m *MTProtoProxy) readSimpleAck(data []byte) ([]byte, error) {
+	if len(data) != 12 {
+		return nil, errors.Errorf("Incorrect data of simple ack: %d", len(data))
+	}
+	data = data[8:12]
+	m.req.Options.WriteHacks.SimpleAck = true
+
+	m.logger.Debugw("Read RPC_SIMPLE_ACK",
+		"counter", m.readCounter,
+		"length", len(data),
+	)
+
+	return data, nil
+}
+
+func (m *MTProtoProxy) readCloseExt(data []byte) ([]byte, error) {
+	m.logger.Debugw("Read RPC_CLOSE_EXT", "counter", m.readCounter)
+
+	return nil, errors.New("Connection has been closed remotely by RPC call")
+}
+
+func (m *MTProtoProxy) Write(p []byte) (int, error) {
+	defer func() {
+		m.writeCounter++
+	}()
+
+	m.logger.Debugw("Write packet",
+		"length", len(p),
+		"counter", m.writeCounter,
+		"simple_ack", m.req.Options.ReadHacks.SimpleAck,
+		"quick_ack", m.req.Options.ReadHacks.QuickAck,
+	)
+
+	header, flags := m.req.MakeHeader(p)
+	if ce := m.logger.Desugar().Check(zap.DebugLevel, "RPC_PROXY_REQ header"); ce != nil {
+		ce.Write(
+			zap.Int("length", len(p)),
+			zap.Uint32("counter", m.writeCounter),
+			zap.Bool("simple_ack", m.req.Options.ReadHacks.QuickAck),
+			zap.Bool("quick_ack", m.req.Options.ReadHacks.SimpleAck),
+			zap.String("header", fmt.Sprintf("%v", header.Bytes())),
+			zap.Stringer("flags", flags),
+		)
+	}
+	header.Write(p)
+
+	if _, err := m.conn.Write(header.Bytes()); err != nil {
+		return 0, err
+	}
+
+	return len(p), nil
+}
+
+func (m *MTProtoProxy) Logger() *zap.SugaredLogger {
+	return m.logger
+}
+
+func (m *MTProtoProxy) LocalAddr() *net.TCPAddr {
+	return m.conn.LocalAddr()
+}
+
+func (m *MTProtoProxy) RemoteAddr() *net.TCPAddr {
+	return m.conn.RemoteAddr()
+}
+
+func (m *MTProtoProxy) Close() error {
+	return m.conn.Close()
+}
+
+func NewMTProtoProxy(conn PacketReadWriteCloser, connOpts *mtproto.ConnectionOpts, adTag []byte) (PacketReadWriteCloser, error) {
+	req, err := rpc.NewProxyRequest(connOpts.ClientAddr, conn.LocalAddr(), connOpts, adTag)
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot create new RPC proxy request")
+	}
+
+	return &MTProtoProxy{
+		conn:   conn,
+		logger: conn.Logger().Named("mtproto-proxy"),
+		req:    req,
+	}, nil
+}

wrappers/rwcaddr.go

@@ -1,13 +0,0 @@
-package wrappers
-
-import (
-	"io"
-	"net"
-)
-
-type ReadWriteCloserWithAddr interface {
-	io.ReadWriteCloser
-
-	LocalAddr() *net.TCPAddr
-	RemoteAddr() *net.TCPAddr
-}

wrappers/streamcipher.go

@@ -0,0 +1,58 @@
+package wrappers
+
+import (
+	"crypto/cipher"
+	"net"
+
+	"github.com/juju/errors"
+	"go.uber.org/zap"
+)
+
+type StreamCipher struct {
+	encryptor cipher.Stream
+	decryptor cipher.Stream
+	conn      StreamReadWriteCloser
+	logger    *zap.SugaredLogger
+}
+
+func (s *StreamCipher) Read(p []byte) (int, error) {
+	n, err := s.conn.Read(p)
+	if err != nil {
+		return 0, errors.Annotate(err, "Cannot read stream ciphered data")
+	}
+	s.decryptor.XORKeyStream(p, p[:n])
+
+	return n, nil
+}
+
+func (s *StreamCipher) Write(p []byte) (int, error) {
+	encrypted := make([]byte, len(p))
+	s.encryptor.XORKeyStream(encrypted, p)
+
+	return s.conn.Write(encrypted)
+}
+
+func (s *StreamCipher) Logger() *zap.SugaredLogger {
+	return s.logger
+}
+
+func (s *StreamCipher) LocalAddr() *net.TCPAddr {
+	return s.conn.LocalAddr()
+}
+
+func (s *StreamCipher) RemoteAddr() *net.TCPAddr {
+	return s.conn.RemoteAddr()
+}
+
+func (s *StreamCipher) Close() error {
+	return s.conn.Close()
+}
+
+func NewStreamCipher(conn StreamReadWriteCloser, encryptor, decryptor cipher.Stream) StreamReadWriteCloser {
+	return &StreamCipher{
+		conn:      conn,
+		logger:    conn.Logger().Named("stream-cipher"),
+		encryptor: encryptor,
+		decryptor: decryptor,
+	}
+}

wrappers/streamcipherrwc.go

@@ -1,62 +0,0 @@
-package wrappers
-
-import (
-	"crypto/cipher"
-	"net"
-)
-
-// StreamCipherReadWriteCloser is a ReadWriteCloser which ciphers
-// incoming and outgoing data with givem cipher.Stream instances.
-type StreamCipherReadWriteCloserWithAddr struct {
-	encryptor cipher.Stream
-	decryptor cipher.Stream
-	conn      ReadWriteCloserWithAddr
-}
-
-// Read reads from connection
-func (c *StreamCipherReadWriteCloserWithAddr) Read(p []byte) (n int, err error) {
-	n, err = c.conn.Read(p)
-	c.decryptor.XORKeyStream(p, p[:n])
-	return
-}
-
-// Write writes into connection.
-func (c *StreamCipherReadWriteCloserWithAddr) Write(p []byte) (int, error) {
-	// This is to decrease an amount of allocations. Unfortunately, escape
-	// analysis in (at least Golang 1.10) is absolutely not perfect. For
-	// example, it understands that we want to have a slice locally, right?
-	// But since slice is effectively 2 ints + uintptr to [number]byte, the
-	// most heavyweight part is placed in heap.
-	buf := getBuffer()
-	defer putBuffer(buf)
-	buf.Grow(len(p))
-	buf.Write(p)
-
-	encrypted := buf.Bytes()
-	c.encryptor.XORKeyStream(encrypted, p)
-
-	return c.conn.Write(encrypted)
-}
-
-// Close closes underlying connection.
-func (c *StreamCipherReadWriteCloserWithAddr) Close() error {
-	return c.conn.Close()
-}
-
-func (c *StreamCipherReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return c.conn.LocalAddr()
-}
-
-func (c *StreamCipherReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return c.conn.RemoteAddr()
-}
-
-// NewStreamCipherRWC returns wrapper which transparently
-// encrypts/decrypts traffic with obfuscated2 protocol.
-func NewStreamCipherRWC(conn ReadWriteCloserWithAddr, encryptor, decryptor cipher.Stream) ReadWriteCloserWithAddr {
-	return &StreamCipherReadWriteCloserWithAddr{
-		conn:      conn,
-		encryptor: encryptor,
-		decryptor: decryptor,
-	}
-}

wrappers/timeoutrwc.go

@@ -1,55 +0,0 @@
-package wrappers
-
-import (
-	"net"
-	"time"
-
-	"github.com/9seconds/mtg/config"
-)
-
-type TimeoutReadWriteCloserWithAddr struct {
-	conn       net.Conn
-	publicIPv4 net.IP
-	publicIPv6 net.IP
-}
-
-func (t *TimeoutReadWriteCloserWithAddr) Read(p []byte) (int, error) {
-	t.conn.SetReadDeadline(time.Now().Add(config.TimeoutRead))
-	return t.conn.Read(p)
-}
-
-func (t *TimeoutReadWriteCloserWithAddr) Write(p []byte) (int, error) {
-	t.conn.SetWriteDeadline(time.Now().Add(config.TimeoutWrite))
-	return t.conn.Write(p)
-}
-
-func (t *TimeoutReadWriteCloserWithAddr) Close() error {
-	return t.conn.Close()
-}
-
-func (t *TimeoutReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return t.conn.RemoteAddr().(*net.TCPAddr)
-}
-
-func (t *TimeoutReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	addr := t.conn.LocalAddr().(*net.TCPAddr)
-	newAddr := *addr
-
-	if t.RemoteAddr().IP.To4() != nil {
-		if t.publicIPv4 != nil {
-			newAddr.IP = t.publicIPv4
-		}
-	} else if t.publicIPv6 != nil {
-		newAddr.IP = t.publicIPv6
-	}
-
-	return &newAddr
-}
-
-func NewTimeoutRWC(conn net.Conn, ipv4, ipv6 net.IP) ReadWriteCloserWithAddr {
-	return &TimeoutReadWriteCloserWithAddr{
-		conn:       conn,
-		publicIPv4: ipv4,
-		publicIPv6: ipv6,
-	}
-}

wrappers/trafficrwc.go

@@ -1,47 +0,0 @@
-package wrappers
-
-import "net"
-
-// TrafficReadWriteCloser counts an amount of ingress/egress traffic by
-// calling given callbacks.
-type TrafficReadWriteCloserWithAddr struct {
-	conn          ReadWriteCloserWithAddr
-	readCallback  func(int)
-	writeCallback func(int)
-}
-
-// Read reads from connection
-func (t *TrafficReadWriteCloserWithAddr) Read(p []byte) (n int, err error) {
-	n, err = t.conn.Read(p)
-	t.readCallback(n)
-	return
-}
-
-// Write writes into connection.
-func (t *TrafficReadWriteCloserWithAddr) Write(p []byte) (n int, err error) {
-	n, err = t.conn.Write(p)
-	t.writeCallback(n)
-	return
-}
-
-// Close closes underlying connection.
-func (t *TrafficReadWriteCloserWithAddr) Close() error {
-	return t.conn.Close()
-}
-
-func (t *TrafficReadWriteCloserWithAddr) LocalAddr() *net.TCPAddr {
-	return t.conn.LocalAddr()
-}
-
-func (t *TrafficReadWriteCloserWithAddr) RemoteAddr() *net.TCPAddr {
-	return t.conn.RemoteAddr()
-}
-
-// NewTrafficRWC wraps ReadWriteCloser to have read/write callbacks.
-func NewTrafficRWC(conn ReadWriteCloserWithAddr, readCallback, writeCallback func(int)) ReadWriteCloserWithAddr {
-	return &TrafficReadWriteCloserWithAddr{
-		conn:          conn,
-		readCallback:  readCallback,
-		writeCallback: writeCallback,
-	}
-}

wrappers/wrap.go

@@ -0,0 +1,85 @@
+package wrappers
+
+import (
+	"io"
+	"net"
+
+	"go.uber.org/zap"
+)
+
+type Wrap interface {
+	Logger() *zap.SugaredLogger
+	LocalAddr() *net.TCPAddr
+	RemoteAddr() *net.TCPAddr
+}
+
+type Writer interface {
+	io.Writer
+	Wrap
+}
+
+type Closer interface {
+	io.Closer
+	Wrap
+}
+
+type WriteCloser interface {
+	io.Closer
+	Writer
+}
+
+type StreamReader interface {
+	io.Reader
+	Wrap
+}
+
+type StreamReadCloser interface {
+	io.Closer
+	StreamReader
+}
+
+type StreamReadWriter interface {
+	io.Writer
+	StreamReader
+}
+
+type StreamWriteCloser interface {
+	io.WriteCloser
+	Wrap
+}
+
+type StreamReadWriteCloser interface {
+	io.Closer
+	StreamReadWriter
+}
+
+type PacketReader interface {
+	Read() ([]byte, error)
+	Wrap
+}
+
+type PacketWriter interface {
+	io.Writer
+	Wrap
+}
+
+type PacketReadWriter interface {
+	io.Writer
+	PacketReader
+}
+
+type PacketReadCloser interface {
+	io.Closer
+	PacketReader
+}
+
+type PacketWriteCloser interface {
+	io.Writer
+	io.Closer
+	Wrap
+}
+
+type PacketReadWriteCloser interface {
+	io.Closer
+	PacketReadWriter
+}