diff --git a/.github/workflows/stale.yml b/.github/workflows/stale.yml
index 3856b59..f7fd285 100644
--- a/.github/workflows/stale.yml
+++ b/.github/workflows/stale.yml
@@ -13,3 +13,5 @@ jobs:
           days-before-stale: 90
           days-before-close: 5
           exempt-issue-labels: "bug,enhancement"
+          exempt-pr-labels: "bug,enhancement"
+          
\ No newline at end of file
diff --git a/proxy/tproxy/tproxy.go b/proxy/tproxy/tproxy.go
index 36ce390..e122bc7 100644
--- a/proxy/tproxy/tproxy.go
+++ b/proxy/tproxy/tproxy.go
@@ -10,8 +10,6 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-const IPV6_RECVORIGDSTADDR = 0x4a
-
 // ref: https://github.com/LiamHaworth/go-tproxy/blob/master/tproxy_udp.go
 // MIT License by @LiamHaworth
 
@@ -65,7 +63,7 @@ func ReadFromUDP(conn *net.UDPConn, b []byte) (int, *net.UDPAddr, *net.UDPAddr,
 			port := binary.BigEndian.Uint16(msg.Data[2:4])
 			return n, addr, &net.UDPAddr{IP: ip, Port: int(port)}, nil
 		}
-		if msg.Header.Level == syscall.SOL_IPV6 && msg.Header.Type == IPV6_RECVORIGDSTADDR {
+		if msg.Header.Level == syscall.SOL_IPV6 && msg.Header.Type == unix.IPV6_RECVORIGDSTADDR {
 			ip := net.IP(msg.Data[8:24])
 			port := binary.BigEndian.Uint16(msg.Data[2:4])
 			return n, addr, &net.UDPAddr{IP: ip, Port: int(port)}, nil
diff --git a/proxy/vmess/chunk_size_parser.go b/proxy/vmess/size.go
similarity index 80%
rename from proxy/vmess/chunk_size_parser.go
rename to proxy/vmess/size.go
index e173a14..224acc7 100644
--- a/proxy/vmess/chunk_size_parser.go
+++ b/proxy/vmess/size.go
@@ -18,11 +18,13 @@ type ChunkSizeDecoder interface {
 	Decode([]byte) (uint16, error)
 }
 
+// ShakeSizeParser implements ChunkSizeEncoder & ChunkSizeDecoder.
 type ShakeSizeParser struct {
 	shake  sha3.ShakeHash
 	buffer [2]byte
 }
 
+// NewShakeSizeParser returns a new ShakeSizeParser.
 func NewShakeSizeParser(nonce []byte) *ShakeSizeParser {
 	shake := sha3.NewShake128()
 	shake.Write(nonce)
@@ -31,6 +33,7 @@ func NewShakeSizeParser(nonce []byte) *ShakeSizeParser {
 	}
 }
 
+// SizeBytes implements ChunkSizeEncoder method.
 func (*ShakeSizeParser) SizeBytes() int32 {
 	return 2
 }
@@ -40,12 +43,14 @@ func (s *ShakeSizeParser) next() uint16 {
 	return binary.BigEndian.Uint16(s.buffer[:])
 }
 
+// Decode implements ChunkSizeDecoder method.
 func (s *ShakeSizeParser) Decode(b []byte) (uint16, error) {
 	mask := s.next()
 	size := binary.BigEndian.Uint16(b)
 	return mask ^ size, nil
 }
 
+// Encode implements ChunkSizeEncoder method.
 func (s *ShakeSizeParser) Encode(size uint16, b []byte) []byte {
 	mask := s.next()
 	binary.BigEndian.PutUint16(b, mask^size)