Improve sniffer

common/sniff/bittorrent.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/sagernet/sing-box/adapter"
 	C "github.com/sagernet/sing-box/constant"
+	E "github.com/sagernet/sing/common/exceptions"
 )
 
 const (
@@ -23,7 +24,7 @@ func BitTorrent(_ context.Context, metadata *adapter.InboundContext, reader io.R
 	var first byte
 	err := binary.Read(reader, binary.BigEndian, &first)
 	if err != nil {
-		return err
+		return E.Cause1(ErrNeedMoreData, err)
 	}
 
 	if first != 19 {
@@ -33,7 +34,7 @@ func BitTorrent(_ context.Context, metadata *adapter.InboundContext, reader io.R
 	var protocol [19]byte
 	_, err = reader.Read(protocol[:])
 	if err != nil {
-		return err
+		return E.Cause1(ErrNeedMoreData, err)
 	}
 	if string(protocol[:]) != "BitTorrent protocol" {
 		return os.ErrInvalid