More server error messages

common/exceptions/error.go

@@ -9,24 +9,36 @@ import (
 	"syscall"
 )
 
-type exception struct {
+type causeError struct {
 	message string
 	cause   error
 }
 
-func (e exception) Error() string {
+func (e *causeError) Error() string {
 	if e.cause == nil {
 		return e.message
 	}
 	return e.message + ": " + e.cause.Error()
 }
 
-func (e exception) Unwrap() error {
+func (e *causeError) Unwrap() error {
 	return e.cause
 }
 
-func (e exception) Is(err error) bool {
+type extendedError struct {
-	return e == err || errors.Is(e.cause, err)
+	message string
+	cause   error
+}
+
+func (e *extendedError) Error() string {
+	if e.cause == nil {
+		return e.message
+	}
+	return e.cause.Error() + e.message
+}
+
+func (e *extendedError) Unwrap() error {
+	return e.cause
 }
 
 func New(message ...any) error {
@@ -34,7 +46,11 @@ func New(message ...any) error {
 }
 
 func Cause(cause error, message ...any) error {
-	return exception{fmt.Sprint(message...), cause}
+	return &causeError{fmt.Sprint(message...), cause}
+}
+
+func Extend(cause error, message ...any) error {
+	return &extendedError{fmt.Sprint(message...), cause}
 }
 
 func IsClosed(err error) bool {

protocol/shadowsocks/shadowaead_2022/protocol.go

@@ -317,7 +317,7 @@ func (c *clientConn) readResponse() error {
 		return err
 	}
 	if headerType != HeaderTypeServer {
-		return ErrBadHeaderType
+		return E.Extend(ErrBadHeaderType, "expected ", HeaderTypeServer, ", got ", headerType)
 	}
 
 	var epoch uint64
@@ -328,7 +328,7 @@ func (c *clientConn) readResponse() error {
 
 	diff := int(math.Abs(float64(time.Now().Unix() - int64(epoch))))
 	if diff > 30 {
-		return ErrBadTimestamp
+		return E.Extend(ErrBadTimestamp, "received ", epoch, ", diff ", diff, "s")
 	}
 
 	_requestSalt := buf.Make(c.keySaltLength)
@@ -525,7 +525,7 @@ func (c *clientPacketConn) ReadPacket(buffer *buf.Buffer) (M.Socksaddr, error) {
 		return M.Socksaddr{}, err
 	}
 	if headerType != HeaderTypeServer {
-		return M.Socksaddr{}, ErrBadHeaderType
+		return M.Socksaddr{}, E.Extend(ErrBadHeaderType, "expected ", HeaderTypeServer, ", got ", headerType)
 	}
 
 	var epoch uint64
@@ -536,7 +536,7 @@ func (c *clientPacketConn) ReadPacket(buffer *buf.Buffer) (M.Socksaddr, error) {
 
 	diff := int(math.Abs(float64(time.Now().Unix() - int64(epoch))))
 	if diff > 30 {
-		return M.Socksaddr{}, ErrBadTimestamp
+		return M.Socksaddr{}, E.Extend(ErrBadTimestamp, "received ", epoch, ", diff ", diff, "s")
 	}
 
 	if sessionId == c.session.remoteSessionId {

protocol/shadowsocks/shadowaead_2022/service.go

@@ -138,7 +138,7 @@ func (s *Service) newConnection(ctx context.Context, conn net.Conn, metadata M.M
 
 	err = reader.ReadChunk(header[s.keySaltLength:])
 	if err != nil {
-		return E.Cause(err, "read request fixed length chunk")
+		return err
 	}
 
 	headerType, err := reader.ReadByte()
@@ -147,7 +147,7 @@ func (s *Service) newConnection(ctx context.Context, conn net.Conn, metadata M.M
 	}
 
 	if headerType != HeaderTypeClient {
-		return ErrBadHeaderType
+		return E.Extend(ErrBadHeaderType, "expected ", HeaderTypeClient, ", got ", headerType)
 	}
 
 	var epoch uint64
@@ -158,7 +158,7 @@ func (s *Service) newConnection(ctx context.Context, conn net.Conn, metadata M.M
 
 	diff := int(math.Abs(float64(time.Now().Unix() - int64(epoch))))
 	if diff > 30 {
-		return ErrBadTimestamp
+		return E.Extend(ErrBadTimestamp, "received ", epoch, ", diff ", diff, "s")
 	}
 
 	var length uint16
@@ -356,7 +356,7 @@ process:
 		goto returnErr
 	}
 	if headerType != HeaderTypeClient {
-		err = ErrBadHeaderType
+		err = E.Extend(ErrBadHeaderType, "expected ", HeaderTypeClient, ", got ", headerType)
 		goto returnErr
 	}
 
@@ -367,7 +367,7 @@ process:
 	}
 	diff := int(math.Abs(float64(time.Now().Unix() - int64(epoch))))
 	if diff > 30 {
-		err = ErrBadTimestamp
+		err = E.Extend(ErrBadTimestamp, "received ", epoch, ", diff ", diff, "s")
 		goto returnErr
 	}
 

protocol/shadowsocks/shadowaead_2022/service_multi.go

@@ -145,7 +145,7 @@ func (s *MultiService[U]) newConnection(ctx context.Context, conn net.Conn, meta
 	}
 
 	if headerType != HeaderTypeClient {
-		return ErrBadHeaderType
+		return E.Extend(ErrBadHeaderType, "expected ", HeaderTypeClient, ", got ", headerType)
 	}
 
 	var epoch uint64
@@ -155,7 +155,7 @@ func (s *MultiService[U]) newConnection(ctx context.Context, conn net.Conn, meta
 	}
 	diff := int(math.Abs(float64(time.Now().Unix() - int64(epoch))))
 	if diff > 30 {
-		return ErrBadTimestamp
+		return E.Extend(ErrBadTimestamp, "received ", epoch, ", diff ", diff, "s")
 	}
 	var length uint16
 	err = binary.Read(reader, binary.BigEndian, &length)
@@ -284,7 +284,7 @@ process:
 		goto returnErr
 	}
 	if headerType != HeaderTypeClient {
-		err = ErrBadHeaderType
+		err = E.Extend(ErrBadHeaderType, "expected ", HeaderTypeClient, ", got ", headerType)
 		goto returnErr
 	}
 
@@ -295,7 +295,7 @@ process:
 	}
 	diff := int(math.Abs(float64(time.Now().Unix() - int64(epoch))))
 	if diff > 30 {
-		err = ErrBadTimestamp
+		err = E.Extend(ErrBadTimestamp, "received ", epoch, ", diff ", diff, "s")
 		goto returnErr
 	}