start working on l2tp protocol

bufpool.go

@@ -4,25 +4,12 @@ package wpn
 import (
 	"bytes"
 	"sync"
-)
 
-const ipPacketMaxSize = 65536
-var ipBufPool = sync.Pool{
-	New: func()(any){
-		buf := make([]byte, ipPacketMaxSize)
-		return &buf
-	},
-}
-
-func getIPPktBuf()(buf []byte, free func()){
-	p := ipBufPool.Get().(*[]byte)
-	return *p, func(){
-		ipBufPool.Put(p)
-	}
-}
+	"github.com/kmcsr/wpn/internal/pool"
+)
 
 var packetFormatBufPool = sync.Pool{
 	New: func()(any){
-		return bytes.NewBuffer(make([]byte, 0, ipPacketMaxSize + 1024))
+		return bytes.NewBuffer(make([]byte, 0, pool.IPPacketMaxSize + 1024))
 	},
 }

client/desktop/main.go

@@ -1,4 +1,5 @@
 
+// Copyright (C) 2023  Kevin Z <[email protected]>
 package main
 
 import (
@@ -11,8 +12,7 @@ import (
 	"time"
 
 	"github.com/kmcsr/wpn"
-	"github.com/kmcsr/wpn/socks5"
-	"github.com/kmcsr/wpn/wssocks"
+	"github.com/kmcsr/wpn/l2tp"
 )
 
 func main(){
@@ -23,7 +23,7 @@ func main(){
 	{
 		ping, err := client.Ping()
 		if err != nil {
-			loger.Fatalf("Cannot ping the server: %v", err)
+			// loger.Fatalf("Cannot ping the server: %v", err)
 		}
 		loger.Infof("Connected to the server: ping=%v", ping)
 	}
@@ -42,20 +42,16 @@ func main(){
 			}
 		}
 	}()
-	shandler := &wssocks.Handler{
-		Client: client,
-	}
-	server := &socks5.Server{
-		Addr: config.SocksAddr,
-		Handler: shandler,
-		DialTimeout: time.Second * 30,
+	server := &l2tp.Server{
+		// Addr: config.SocksAddr,
+		Logger: loger,
 	}
 
 	go func(){
 		defer close(done)
-		loger.Infof("Starting socks5 server on %q", server.Addr)
+		loger.Infof("Starting L2TP server at %q", server.Addr)
 		if err := server.ListenAndServe(); err != nil && !errors.Is(err, net.ErrClosed) {
-			loger.Fatalf("Error when running socks5 server: %v", err)
+			loger.Fatalf("Error when running L2TP server: %v", err)
 		}
 	}()
 

conn.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"nhooyr.io/websocket"
+	"github.com/kmcsr/wpn/internal/pool"
 )
 
 var (
@@ -326,7 +327,7 @@ func (c *Conn)handleBinary(r io.Reader)(err error){
 		data := &packetDataT{
 			addr: &addr,
 		}
-		buf, data.freeBuf = getIPPktBuf()
+		buf, data.freeBuf = pool.GetIPPacketBuf()
 		var n int
 		if n, err = br.Read(buf); err != nil {
 			if errors.Is(err, io.EOF) {
@@ -533,7 +534,7 @@ func (c *Conn)serveStream()(err error){
 		return
 	}
 	defer conn.Close()
-	buf, freeBuf := getIPPktBuf()
+	buf, freeBuf := pool.GetIPPacketBuf()
 	defer freeBuf()
 	for {
 		var n int
@@ -582,7 +583,7 @@ func (c *Conn)servePacket()(err error){
 		return
 	}
 	defer conn.Close()
-	buf, freeBuf := getIPPktBuf()
+	buf, freeBuf := pool.GetIPPacketBuf()
 	defer freeBuf()
 	for {
 		var (

internal/pool/ippkt.go

@@ -0,0 +1,21 @@
+
+package pool
+
+import (
+	"sync"
+)
+
+const IPPacketMaxSize = 65536
+var ipBufPool = sync.Pool{
+	New: func()(any){
+		buf := make([]byte, IPPacketMaxSize)
+		return &buf
+	},
+}
+
+func GetIPPacketBuf()(buf []byte, free func()){
+	p := ipBufPool.Get().(*[]byte)
+	return *p, func(){
+		ipBufPool.Put(p)
+	}
+}

l2tp/errors.go

@@ -0,0 +1,72 @@
+
+package l2tp
+
+import (
+	"errors"
+	"fmt"
+	"runtime"
+	"sync"
+)
+
+var WrongLengthErr = errors.New("Wrong length of the packet")
+
+type VersionError struct {
+	Version byte
+}
+
+func (e *VersionError)Error()(string){
+	return fmt.Sprintf("Unsupport version %d, support %d", e.Version, L2TPVersion)
+}
+
+type UnexpectFlagValue struct {
+	Flag string
+	Expect bool
+}
+
+func (e *UnexpectFlagValue)Error()(string){
+	if e.Expect {
+		return fmt.Sprintf("Flag %s is expected to set", e.Flag)
+	}
+	return fmt.Sprintf("Flag %s is unexpected to set", e.Flag)
+}
+
+type PanicError struct {
+	err any
+	stacktrace string
+}
+
+var stackBufPool = sync.Pool{
+	New: func()(any){
+		buf := make([]byte, 1024)
+		return &buf
+	},
+}
+
+func getStack()(string){
+	buf := *(stackBufPool.Get().(*[]byte))
+	for {
+		n := runtime.Stack(buf, false)
+		if n < len(buf) {
+			s := (string)(buf[:n])
+			stackBufPool.Put(&buf)
+			return s
+		}
+		stackBufPool.Put(&buf)
+		buf = make([]byte, len(buf) + 1024)
+	}
+}
+
+func recoverAsError()(*PanicError){
+	err := recover()
+	if err == nil {
+		return nil
+	}
+	return &PanicError{
+		err: err,
+		stacktrace: getStack(),
+	}
+}
+
+func (e *PanicError)Error()(string){
+	return fmt.Sprintf("panic: %v\n", e.err) + e.stacktrace
+}