add kcp dialer

pkg/dialer/dialer.go

@@ -14,7 +14,7 @@ type Dialer interface {
 }
 
 type Handshaker interface {
-	Handshake(ctx context.Context, conn net.Conn) (net.Conn, error)
+	Handshake(ctx context.Context, conn net.Conn, opts ...HandshakeOption) (net.Conn, error)
 }
 
 type Multiplexer interface {

pkg/dialer/kcp/conn.go

@@ -0,0 +1,56 @@
+package kcp
+
+import (
+	"net"
+
+	"github.com/xtaci/smux"
+)
+
+type muxSession struct {
+	conn    net.Conn
+	session *smux.Session
+}
+
+func (session *muxSession) GetConn() (net.Conn, error) {
+	return session.session.OpenStream()
+}
+
+func (session *muxSession) Accept() (net.Conn, error) {
+	return session.session.AcceptStream()
+}
+
+func (session *muxSession) Close() error {
+	if session.session == nil {
+		return nil
+	}
+	return session.session.Close()
+}
+
+func (session *muxSession) IsClosed() bool {
+	if session.session == nil {
+		return true
+	}
+	return session.session.IsClosed()
+}
+
+func (session *muxSession) NumStreams() int {
+	return session.session.NumStreams()
+}
+
+type fakeTCPConn struct {
+	raddr net.Addr
+	net.PacketConn
+}
+
+func (c *fakeTCPConn) Read(b []byte) (n int, err error) {
+	n, _, err = c.ReadFrom(b)
+	return
+}
+
+func (c *fakeTCPConn) Write(b []byte) (n int, err error) {
+	return c.WriteTo(b, c.raddr)
+}
+
+func (c *fakeTCPConn) RemoteAddr() net.Addr {
+	return c.raddr
+}

pkg/dialer/kcp/dialer.go

@@ -0,0 +1,183 @@
+package kcp
+
+import (
+	"context"
+	"errors"
+	"net"
+	"sync"
+	"time"
+
+	kcp_util "github.com/go-gost/gost/pkg/common/util/kcp"
+	"github.com/go-gost/gost/pkg/dialer"
+	"github.com/go-gost/gost/pkg/logger"
+	md "github.com/go-gost/gost/pkg/metadata"
+	"github.com/go-gost/gost/pkg/registry"
+	"github.com/xtaci/kcp-go/v5"
+	"github.com/xtaci/smux"
+	"github.com/xtaci/tcpraw"
+)
+
+func init() {
+	registry.RegisterDialer("kcp", NewDialer)
+}
+
+type kcpDialer struct {
+	sessions     map[string]*muxSession
+	sessionMutex sync.Mutex
+	logger       logger.Logger
+	md           metadata
+}
+
+func NewDialer(opts ...dialer.Option) dialer.Dialer {
+	options := &dialer.Options{}
+	for _, opt := range opts {
+		opt(options)
+	}
+
+	return &kcpDialer{
+		sessions: make(map[string]*muxSession),
+		logger:   options.Logger,
+	}
+}
+
+func (d *kcpDialer) Init(md md.Metadata) (err error) {
+	if err = d.parseMetadata(md); err != nil {
+		return
+	}
+
+	d.md.config.Init()
+
+	return nil
+}
+
+// IsMultiplex implements dialer.Multiplexer interface.
+func (d *kcpDialer) IsMultiplex() bool {
+	return true
+}
+
+func (d *kcpDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOption) (conn net.Conn, err error) {
+	var options dialer.DialOptions
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	d.sessionMutex.Lock()
+	defer d.sessionMutex.Unlock()
+
+	session, ok := d.sessions[addr]
+	if session != nil && session.IsClosed() {
+		delete(d.sessions, addr) // session is dead
+		ok = false
+	}
+	if !ok {
+		raddr, err := net.ResolveUDPAddr("udp", addr)
+		if err != nil {
+			return nil, err
+		}
+
+		if d.md.config.TCP {
+			pc, err := tcpraw.Dial("tcp", addr)
+			if err != nil {
+				return nil, err
+			}
+			conn = &fakeTCPConn{
+				raddr:      raddr,
+				PacketConn: pc,
+			}
+		} else {
+			conn, err = net.ListenUDP("udp", nil)
+			if err != nil {
+				return nil, err
+			}
+		}
+		session = &muxSession{conn: conn}
+		d.sessions[addr] = session
+	}
+
+	return session.conn, err
+}
+
+// Handshake implements dialer.Handshaker
+func (d *kcpDialer) Handshake(ctx context.Context, conn net.Conn, options ...dialer.HandshakeOption) (net.Conn, error) {
+	opts := &dialer.HandshakeOptions{}
+	for _, option := range options {
+		option(opts)
+	}
+	config := d.md.config
+
+	d.sessionMutex.Lock()
+	defer d.sessionMutex.Unlock()
+
+	if d.md.handshakeTimeout > 0 {
+		conn.SetDeadline(time.Now().Add(d.md.handshakeTimeout))
+		defer conn.SetDeadline(time.Time{})
+	}
+
+	session, ok := d.sessions[opts.Addr]
+	if !ok || session.session == nil {
+		s, err := d.initSession(opts.Addr, conn, config)
+		if err != nil {
+			d.logger.Error(err)
+			conn.Close()
+			delete(d.sessions, opts.Addr)
+			return nil, err
+		}
+		session = s
+		d.sessions[opts.Addr] = session
+	}
+	cc, err := session.GetConn()
+	if err != nil {
+		session.Close()
+		delete(d.sessions, opts.Addr)
+		return nil, err
+	}
+
+	return cc, nil
+}
+
+func (d *kcpDialer) initSession(addr string, conn net.Conn, config *kcp_util.Config) (*muxSession, error) {
+	pc, ok := conn.(net.PacketConn)
+	if !ok {
+		return nil, errors.New("wrong connection type")
+	}
+
+	kcpconn, err := kcp.NewConn(addr,
+		kcp_util.BlockCrypt(config.Key, config.Crypt, kcp_util.DefaultSalt),
+		config.DataShard, config.ParityShard, pc)
+	if err != nil {
+		return nil, err
+	}
+
+	kcpconn.SetStreamMode(true)
+	kcpconn.SetWriteDelay(false)
+	kcpconn.SetNoDelay(config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
+	kcpconn.SetWindowSize(config.SndWnd, config.RcvWnd)
+	kcpconn.SetMtu(config.MTU)
+	kcpconn.SetACKNoDelay(config.AckNodelay)
+
+	if config.DSCP > 0 {
+		if err := kcpconn.SetDSCP(config.DSCP); err != nil {
+			d.logger.Warn("SetDSCP: ", err)
+		}
+	}
+	if err := kcpconn.SetReadBuffer(config.SockBuf); err != nil {
+		d.logger.Warn("SetReadBuffer: ", err)
+	}
+	if err := kcpconn.SetWriteBuffer(config.SockBuf); err != nil {
+		d.logger.Warn("SetWriteBuffer: ", err)
+	}
+
+	// stream multiplex
+	smuxConfig := smux.DefaultConfig()
+	smuxConfig.MaxReceiveBuffer = config.SockBuf
+	smuxConfig.KeepAliveInterval = time.Duration(config.KeepAlive) * time.Second
+	var cc net.Conn = kcpconn
+	if !config.NoComp {
+		cc = kcp_util.CompStreamConn(kcpconn)
+	}
+	session, err := smux.Client(cc, smuxConfig)
+	if err != nil {
+		return nil, err
+	}
+	return &muxSession{conn: conn, session: session}, nil
+}

pkg/dialer/kcp/metadata.go

@@ -0,0 +1,46 @@
+package kcp
+
+import (
+	"encoding/json"
+	"time"
+
+	kcp_util "github.com/go-gost/gost/pkg/common/util/kcp"
+	md "github.com/go-gost/gost/pkg/metadata"
+)
+
+type metadata struct {
+	handshakeTimeout time.Duration
+	config           *kcp_util.Config
+}
+
+func (d *kcpDialer) parseMetadata(md md.Metadata) (err error) {
+	const (
+		config           = "config"
+		handshakeTimeout = "handshakeTimeout"
+	)
+
+	if mm, _ := md.Get(config).(map[interface{}]interface{}); len(mm) > 0 {
+		m := make(map[string]interface{})
+		for k, v := range mm {
+			if sk, ok := k.(string); ok {
+				m[sk] = v
+			}
+		}
+		b, err := json.Marshal(m)
+		if err != nil {
+			return err
+		}
+		cfg := &kcp_util.Config{}
+		if err := json.Unmarshal(b, cfg); err != nil {
+			return err
+		}
+		d.md.config = cfg
+	}
+
+	if d.md.config == nil {
+		d.md.config = kcp_util.DefaultConfig
+	}
+
+	d.md.handshakeTimeout = md.GetDuration(handshakeTimeout)
+	return
+}

pkg/dialer/option.go

@@ -30,3 +30,15 @@ func DialFuncDialOption(dialf func(ctx context.Context, addr string) (net.Conn,
 		opts.DialFunc = dialf
 	}
 }
+
+type HandshakeOptions struct {
+	Addr string
+}
+
+type HandshakeOption func(opts *HandshakeOptions)
+
+func AddrHandshakeOption(addr string) HandshakeOption {
+	return func(opts *HandshakeOptions) {
+		opts.Addr = addr
+	}
+}

pkg/dialer/tcp/dialer.go

@@ -40,33 +40,10 @@ func (d *tcpDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOp
 		opt(&options)
 	}
 
-	dial := options.DialFunc
-	if dial != nil {
-		conn, err := dial(ctx, addr)
-		if err != nil {
-			d.logger.Error(err)
-		} else {
-			d.logger.WithFields(map[string]interface{}{
-				"src": conn.LocalAddr().String(),
-				"dst": addr,
-			}).Debug("dial with dial func")
-		}
-		return conn, err
-	}
-
 	var netd net.Dialer
 	conn, err := netd.DialContext(ctx, "tcp", addr)
 	if err != nil {
 		d.logger.Error(err)
-	} else {
-		d.logger.WithFields(map[string]interface{}{
-			"src": conn.LocalAddr().String(),
-			"dst": addr,
-		}).Debug("dial direct")
 	}
 	return conn, err
 }
-
-func (d *tcpDialer) parseMetadata(md md.Metadata) (err error) {
-	return
-}

pkg/dialer/tcp/metadata.go

@@ -1,6 +1,10 @@
 package tcp
 
-import "time"
+import (
+	"time"
+
+	md "github.com/go-gost/gost/pkg/metadata"
+)
 
 const (
 	dialTimeout = "dialTimeout"
@@ -13,3 +17,7 @@ const (
 type metadata struct {
 	dialTimeout time.Duration
 }
+
+func (d *tcpDialer) parseMetadata(md md.Metadata) (err error) {
+	return
+}