Improve copy

go.mod

@@ -28,7 +28,7 @@ require (
 	github.com/sagernet/gomobile v0.1.7
 	github.com/sagernet/gvisor v0.0.0-20250325023245-7a9c0f5725fb
 	github.com/sagernet/quic-go v0.52.0-beta.1
-	github.com/sagernet/sing v0.6.12-0.20250703120903-7081a0c40539
+	github.com/sagernet/sing v0.6.12-0.20250704043954-da981379f151
 	github.com/sagernet/sing-mux v0.3.2
 	github.com/sagernet/sing-quic v0.5.0-beta.2
 	github.com/sagernet/sing-shadowsocks v0.2.8

go.sum

@@ -168,8 +168,8 @@ github.com/sagernet/nftables v0.3.0-beta.4/go.mod h1:OQXAjvjNGGFxaTgVCSTRIhYB5/l
 github.com/sagernet/quic-go v0.52.0-beta.1 h1:hWkojLg64zjV+MJOvJU/kOeWndm3tiEfBLx5foisszs=
 github.com/sagernet/quic-go v0.52.0-beta.1/go.mod h1:OV+V5kEBb8kJS7k29MzDu6oj9GyMc7HA07sE1tedxz4=
 github.com/sagernet/sing v0.6.9/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
-github.com/sagernet/sing v0.6.12-0.20250703120903-7081a0c40539 h1:SK4M4FCNdwV4EiYKIUZ9qM4lr/1NQogJe1YoyYw5DV8=
-github.com/sagernet/sing v0.6.12-0.20250703120903-7081a0c40539/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
+github.com/sagernet/sing v0.6.12-0.20250704043954-da981379f151 h1:UCiQ1d/t5Y9uKAL9ir3i06+ClqS93OGGG8oqB82RMCE=
+github.com/sagernet/sing v0.6.12-0.20250704043954-da981379f151/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
 github.com/sagernet/sing-mux v0.3.2 h1:meZVFiiStvHThb/trcpAkCrmtJOuItG5Dzl1RRP5/NE=
 github.com/sagernet/sing-mux v0.3.2/go.mod h1:pht8iFY4c9Xltj7rhVd208npkNaeCxzyXCgulDPLUDA=
 github.com/sagernet/sing-quic v0.5.0-beta.2 h1:j7KAbBuGmsKwSxVAQL5soJ+wDqxim4/llK2kxB0hSKk=

route/conn.go

@@ -277,7 +277,7 @@ func (m *ConnectionManager) connectionCopy(ctx context.Context, source net.Conn,
 			return
 		}
 	}
-	_, err := bufio.CopyWithCounters(destinationWriter, sourceReader, source, readCounters, writeCounters)
+	_, err := bufio.CopyWithCounters(destinationWriter, sourceReader, source, readCounters, writeCounters, bufio.DefaultIncreaseBufferAfter)
 	if err != nil {
 		common.Close(source, destination)
 	} else if duplexDst, isDuplex := destination.(N.WriteCloser); isDuplex {