use fixed buffer size

handler/tun/client.go

@@ -103,12 +103,10 @@ func (h *tunHandler) transportClient(ctx context.Context, tun io.ReadWriter, con
 	errc := make(chan error, 2)
 
 	go func() {
+		var b [MaxMessageSize]byte
 		for {
 			err := func() error {
-				b := bufpool.Get(h.md.bufferSize)
-				defer bufpool.Put(b)
-
-				n, err := tun.Read(b)
+				n, err := tun.Read(b[:])
 				if err != nil {
 					return fmt.Errorf("%w: read: %s", ErrTun, err.Error())
 				}
@@ -155,12 +153,10 @@ func (h *tunHandler) transportClient(ctx context.Context, tun io.ReadWriter, con
 	}()
 
 	go func() {
+		var b [MaxMessageSize]byte
 		for {
 			err := func() error {
-				b := bufpool.Get(h.md.bufferSize)
-				defer bufpool.Put(b)
-
-				n, err := conn.Read(b)
+				n, err := conn.Read(b[:])
 				if err != nil {
 					return err
 				}
@@ -175,7 +171,7 @@ func (h *tunHandler) transportClient(ctx context.Context, tun io.ReadWriter, con
 					return nil
 				}
 
-				if waterutil.IsIPv4(b) {
+				if waterutil.IsIPv4(b[:n]) {
 					header, err := ipv4.ParseHeader(b[:n])
 					if err != nil {
 						log.Warn(err)

handler/tun/metadata.go

@@ -1,6 +1,7 @@
 package tun
 
 import (
+	"math"
 	"time"
 
 	mdata "github.com/go-gost/core/metadata"
@@ -9,22 +10,16 @@ import (
 
 const (
 	defaultKeepAlivePeriod = 10 * time.Second
-	defaultBufferSize      = 4096
+	MaxMessageSize         = math.MaxUint16
 )
 
 type metadata struct {
-	bufferSize      int
 	keepAlivePeriod time.Duration
 	passphrase      string
 	p2p             bool
 }
 
 func (h *tunHandler) parseMetadata(md mdata.Metadata) (err error) {
-	h.md.bufferSize = mdutil.GetInt(md, "tun.bufsize", "bufsize", "buffersize")
-	if h.md.bufferSize <= 0 {
-		h.md.bufferSize = defaultBufferSize
-	}
-
 	if mdutil.GetBool(md, "tun.keepalive", "keepalive") {
 		h.md.keepAlivePeriod = mdutil.GetDuration(md, "tun.ttl", "ttl")
 		if h.md.keepAlivePeriod <= 0 {

handler/tun/server.go

@@ -8,7 +8,6 @@ import (
 	"net/netip"
 	"time"
 
-	"github.com/go-gost/core/common/bufpool"
 	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/router"
 	xip "github.com/go-gost/x/internal/net/ip"
@@ -42,12 +41,10 @@ func (h *tunHandler) transportServer(ctx context.Context, tun io.ReadWriter, con
 	errc := make(chan error, 1)
 
 	go func() {
+		var b [MaxMessageSize]byte
 		for {
 			err := func() error {
-				b := bufpool.Get(h.md.bufferSize)
-				defer bufpool.Put(b)
-
-				n, err := tun.Read(b)
+				n, err := tun.Read(b[:])
 				if err != nil {
 					return ErrTun
 				}
@@ -110,12 +107,10 @@ func (h *tunHandler) transportServer(ctx context.Context, tun io.ReadWriter, con
 	}()
 
 	go func() {
+		var b [MaxMessageSize]byte
 		for {
 			err := func() error {
-				b := bufpool.Get(h.md.bufferSize)
-				defer bufpool.Put(b)
-
-				n, addr, err := conn.ReadFrom(b)
+				n, addr, err := conn.ReadFrom(b[:])
 				if err != nil {
 					return err
 				}