Rename server to proxy

proxy/server.go

@@ -0,0 +1,159 @@
+package proxy
+
+import (
+	"context"
+	"io"
+	"net"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/9seconds/mtg/obfuscated2"
+	"github.com/juju/errors"
+	uuid "github.com/satori/go.uuid"
+	"go.uber.org/zap"
+)
+
+const bufferSize = 4096
+
+type Server struct {
+	ip           net.IP
+	port         int
+	secret       []byte
+	logger       *zap.SugaredLogger
+	lsock        net.Listener
+	ctx          context.Context
+	readTimeout  time.Duration
+	writeTimeout time.Duration
+}
+
+func (s *Server) Serve() error {
+	lsock, err := net.Listen("tcp", s.Addr())
+	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)
+		}
+	}
+
+	return nil
+}
+
+func (s *Server) Addr() string {
+	return net.JoinHostPort(s.ip.String(), strconv.Itoa(s.port))
+}
+
+func (s *Server) accept(conn net.Conn) {
+	defer conn.Close()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	socketID := s.makeSocketID()
+
+	s.logger.Debugw("Client connected",
+		"secret", s.secret,
+		"addr", conn.RemoteAddr().String(),
+		"socketid", socketID,
+	)
+
+	clientConn, dc, err := s.getClientStream(conn, ctx, cancel, socketID)
+	if err != nil {
+		s.logger.Warnw("Cannot initialize client connection",
+			"secret", s.secret,
+			"addr", conn.RemoteAddr().String(),
+			"socketid", socketID,
+			"error", err,
+		)
+		return
+	}
+	defer clientConn.Close()
+
+	tgConn, err := s.getTelegramStream(dc, ctx, cancel, socketID)
+	if err != nil {
+		s.logger.Warnw("Cannot initialize Telegram connection",
+			"socketid", socketID,
+			"error", err,
+		)
+		return
+	}
+	defer tgConn.Close()
+
+	wait := &sync.WaitGroup{}
+	wait.Add(2)
+	go s.pipe(wait, clientConn, tgConn)
+	go s.pipe(wait, tgConn, clientConn)
+	<-ctx.Done()
+	wait.Wait()
+
+	s.logger.Debugw("Client disconnected",
+		"secret", s.secret,
+		"addr", conn.RemoteAddr().String(),
+		"socketid", socketID,
+	)
+}
+
+func (s *Server) makeSocketID() string {
+	return uuid.NewV4().String()
+}
+
+func (s *Server) getClientStream(conn net.Conn, ctx context.Context, cancel context.CancelFunc, socketID string) (io.ReadWriteCloser, int16, error) {
+	wConn := newTimeoutReadWriteCloser(conn, s.readTimeout, s.writeTimeout)
+	frame, err := obfuscated2.ExtractFrame(wConn)
+	if err != nil {
+		return nil, 0, errors.Annotate(err, "Cannot create client stream")
+	}
+
+	obfs2, dc, err := obfuscated2.ParseObfuscated2ClientFrame(s.secret, frame)
+	if err != nil {
+		return nil, 0, errors.Annotate(err, "Cannot create client stream")
+	}
+
+	wConn = newLogReadWriteCloser(wConn, s.logger, socketID, "client")
+	wConn = newCipherReadWriteCloser(conn, obfs2)
+	wConn = newCtxReadWriteCloser(wConn, ctx, cancel)
+
+	return wConn, dc, nil
+}
+
+func (s *Server) getTelegramStream(dc int16, ctx context.Context, cancel context.CancelFunc, socketID string) (io.ReadWriteCloser, error) {
+	socket, err := dialToTelegram(dc, s.readTimeout)
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot dial")
+	}
+	wConn := newTimeoutReadWriteCloser(socket, s.readTimeout, s.writeTimeout)
+
+	obfs2, frame := obfuscated2.MakeTelegramObfuscated2Frame()
+	if n, err := socket.Write(frame); err != nil || n != len(frame) {
+		return nil, errors.Annotate(err, "Cannot write hadnshake frame")
+	}
+
+	wConn = newLogReadWriteCloser(socket, s.logger, socketID, "telegram")
+	wConn = newCipherReadWriteCloser(wConn, obfs2)
+	wConn = newCtxReadWriteCloser(wConn, ctx, cancel)
+
+	return wConn, nil
+}
+
+func (s *Server) pipe(wait *sync.WaitGroup, reader io.Reader, writer io.Writer) {
+	defer wait.Done()
+
+	buf := make([]byte, bufferSize)
+	io.CopyBuffer(writer, reader, buf)
+}
+
+func NewServer(ip net.IP, port int, secret []byte, logger *zap.SugaredLogger,
+	readTimeout, writeTimeout time.Duration) *Server {
+	return &Server{
+		ip:           ip,
+		port:         port,
+		secret:       secret,
+		ctx:          context.Background(),
+		logger:       logger,
+		readTimeout:  readTimeout,
+		writeTimeout: writeTimeout,
+	}
+}