diff --git a/common/buf/buffered_reader.go b/common/buf/buffered_reader.go
index 8c7630ec..66ef5c06 100644
--- a/common/buf/buffered_reader.go
+++ b/common/buf/buffered_reader.go
@@ -21,33 +21,33 @@ func NewBufferedReader(rawReader io.Reader) *BufferedReader {
 }
 
 // IsBuffered returns true if the internal cache is effective.
-func (v *BufferedReader) IsBuffered() bool {
-	return v.buffered
+func (r *BufferedReader) IsBuffered() bool {
+	return r.buffered
 }
 
 // SetBuffered is to enable or disable internal cache. If cache is disabled,
 // Read() calls will be delegated to the underlying io.Reader directly.
-func (v *BufferedReader) SetBuffered(cached bool) {
-	v.buffered = cached
+func (r *BufferedReader) SetBuffered(cached bool) {
+	r.buffered = cached
 }
 
 // Read implements io.Reader.Read().
-func (v *BufferedReader) Read(b []byte) (int, error) {
-	if !v.buffered || v.buffer == nil {
-		if !v.buffer.IsEmpty() {
-			return v.buffer.Read(b)
+func (r *BufferedReader) Read(b []byte) (int, error) {
+	if !r.buffered || r.buffer == nil {
+		if !r.buffer.IsEmpty() {
+			return r.buffer.Read(b)
 		}
-		return v.reader.Read(b)
+		return r.reader.Read(b)
 	}
-	if v.buffer.IsEmpty() {
-		if err := v.buffer.Reset(ReadFrom(v.reader)); err != nil {
+	if r.buffer.IsEmpty() {
+		if err := r.buffer.Reset(ReadFrom(r.reader)); err != nil {
 			return 0, err
 		}
 	}
 
-	if v.buffer.IsEmpty() {
+	if r.buffer.IsEmpty() {
 		return 0, nil
 	}
 
-	return v.buffer.Read(b)
+	return r.buffer.Read(b)
 }
diff --git a/common/protocol/headers.go b/common/protocol/headers.go
index b9ecd1a9..dd541b68 100644
--- a/common/protocol/headers.go
+++ b/common/protocol/headers.go
@@ -37,22 +37,22 @@ const (
 	RequestOptionChunkMasking = RequestOption(0x04)
 )
 
-func (v RequestOption) Has(option RequestOption) bool {
-	return (v & option) == option
+func (o RequestOption) Has(option RequestOption) bool {
+	return (o & option) == option
 }
 
-func (v *RequestOption) Set(option RequestOption) {
-	*v = (*v | option)
+func (o *RequestOption) Set(option RequestOption) {
+	*o = (*o | option)
 }
 
-func (v *RequestOption) Clear(option RequestOption) {
-	*v = (*v & (^option))
+func (o *RequestOption) Clear(option RequestOption) {
+	*o = (*o & (^option))
 }
 
 type Security byte
 
-func (v Security) Is(t SecurityType) bool {
-	return v == Security(t)
+func (s Security) Is(t SecurityType) bool {
+	return s == Security(t)
 }
 
 func NormSecurity(s Security) Security {
@@ -72,11 +72,11 @@ type RequestHeader struct {
 	User     *User
 }
 
-func (v *RequestHeader) Destination() net.Destination {
-	if v.Command == RequestCommandUDP {
-		return net.UDPDestination(v.Address, v.Port)
+func (h *RequestHeader) Destination() net.Destination {
+	if h.Command == RequestCommandUDP {
+		return net.UDPDestination(h.Address, h.Port)
 	}
-	return net.TCPDestination(v.Address, v.Port)
+	return net.TCPDestination(h.Address, h.Port)
 }
 
 type ResponseOption byte
@@ -85,16 +85,16 @@ const (
 	ResponseOptionConnectionReuse = ResponseOption(0x01)
 )
 
-func (v *ResponseOption) Set(option ResponseOption) {
-	*v = (*v | option)
+func (o *ResponseOption) Set(option ResponseOption) {
+	*o = (*o | option)
 }
 
-func (v ResponseOption) Has(option ResponseOption) bool {
-	return (v & option) == option
+func (o ResponseOption) Has(option ResponseOption) bool {
+	return (o & option) == option
 }
 
-func (v *ResponseOption) Clear(option ResponseOption) {
-	*v = (*v & (^option))
+func (o *ResponseOption) Clear(option ResponseOption) {
+	*o = (*o & (^option))
 }
 
 type ResponseCommand interface{}
@@ -113,15 +113,15 @@ type CommandSwitchAccount struct {
 	ValidMin byte
 }
 
-func (v *SecurityConfig) AsSecurity() Security {
-	if v == nil {
+func (sc *SecurityConfig) AsSecurity() Security {
+	if sc == nil {
 		return Security(SecurityType_LEGACY)
 	}
-	if v.Type == SecurityType_AUTO {
+	if sc.Type == SecurityType_AUTO {
 		if runtime.GOARCH == "amd64" || runtime.GOARCH == "s390x" {
 			return Security(SecurityType_AES128_GCM)
 		}
 		return Security(SecurityType_CHACHA20_POLY1305)
 	}
-	return NormSecurity(Security(v.Type))
+	return NormSecurity(Security(sc.Type))
 }