add socks5 udp relay

pkg/internal/bufpool/pool.go

@@ -2,12 +2,6 @@ package bufpool
 
 import "sync"
 
-var (
-	smallBufferSize  = 1 * 1024  // 1KB buffer
-	mediumBufferSize = 8 * 1024  // 8KB buffer
-	largeBufferSize  = 64 * 1024 // 64KB buffer
-)
-
 var (
 	pools = []struct {
 		size int
@@ -77,24 +71,32 @@ var (
 				},
 			},
 		},
+		{
+			size: 65 * 1024,
+			pool: sync.Pool{
+				New: func() interface{} {
+					return make([]byte, 65*1024)
+				},
+			},
+		},
 	}
 )
 
-// Get returns a buffer size range from (0, 64]KB,
-// panic if size > 64KB.
+// Get returns a buffer size range from (0, 65]KB,
+// panic if size > 65KB.
 func Get(size int) []byte {
 	for i := range pools {
 		if size <= pools[i].size {
 			return pools[i].pool.Get().([]byte)
 		}
 	}
-	panic("size too large (max=64KB)")
+	panic("size too large (max=65KB)")
 }
 
 func Put(b []byte) {
 	for i := range pools {
-		if len(b) == pools[i].size {
-			pools[i].pool.Put(b)
+		if cap(b) == pools[i].size {
+			pools[i].pool.Put(b[:cap(b)])
 		}
 	}
 }

pkg/internal/utils/kcp/kcp.go

@@ -1,4 +1,4 @@
-package utils
+package kcp
 
 import (
 	"net"

pkg/internal/utils/mux/mux.go

@@ -0,0 +1,75 @@
+package mux
+
+import (
+	"net"
+
+	smux "github.com/xtaci/smux"
+)
+
+type MuxSession struct {
+	conn    net.Conn
+	session *smux.Session
+}
+
+func NewMuxSession(conn net.Conn) (*MuxSession, error) {
+	// Upgrade connection to multiplex stream.
+	s, err := smux.Client(conn, smux.DefaultConfig())
+	if err != nil {
+		return nil, err
+	}
+	return &MuxSession{
+		conn:    conn,
+		session: s,
+	}, nil
+}
+
+func (session *MuxSession) GetConn() (net.Conn, error) {
+	stream, err := session.session.OpenStream()
+	if err != nil {
+		return nil, err
+	}
+	return &muxStreamConn{Conn: session.conn, stream: stream}, nil
+}
+
+func (session *MuxSession) Accept() (net.Conn, error) {
+	stream, err := session.session.AcceptStream()
+	if err != nil {
+		return nil, err
+	}
+	return &muxStreamConn{Conn: session.conn, stream: stream}, nil
+}
+
+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 muxStreamConn struct {
+	net.Conn
+	stream *smux.Stream
+}
+
+func (c *muxStreamConn) Read(b []byte) (n int, err error) {
+	return c.stream.Read(b)
+}
+
+func (c *muxStreamConn) Write(b []byte) (n int, err error) {
+	return c.stream.Write(b)
+}
+
+func (c *muxStreamConn) Close() error {
+	return c.stream.Close()
+}

pkg/internal/utils/quic/quic.go

@@ -1,4 +1,4 @@
-package utils
+package quic
 
 import (
 	"crypto/aes"

pkg/internal/utils/socks/socks.go

@@ -0,0 +1,18 @@
+package socks
+
+const (
+	// MethodTLS is an extended SOCKS5 method with tls encryption support.
+	MethodTLS uint8 = 0x80
+	// MethodTLSAuth is an extended SOCKS5 method with tls encryption and authentication support.
+	MethodTLSAuth uint8 = 0x82
+	// MethodMux is an extended SOCKS5 method for stream multiplexing.
+	MethodMux = 0x88
+)
+
+const (
+	// CmdMuxBind is an extended SOCKS5 request CMD for
+	// multiplexing transport with the binding server.
+	CmdMuxBind uint8 = 0xF2
+	// CmdUDPTun is an extended SOCKS5 request CMD for UDP over TCP.
+	CmdUDPTun uint8 = 0xF3
+)

pkg/internal/utils/ss/ss.go

@@ -1,4 +1,4 @@
-package utils
+package ss
 
 import (
 	"bytes"

pkg/internal/utils/tls/tls.go

@@ -1,4 +1,4 @@
-package utils
+package tls
 
 import (
 	"crypto/tls"

pkg/internal/utils/ws/ws.go

@@ -1,4 +1,4 @@
-package utils
+package ws
 
 import (
 	"net"