Improve direct copy

go.mod

@@ -28,13 +28,13 @@ 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 v0.6.12-0.20250704043954-da981379f151
+	github.com/sagernet/sing v0.6.12-0.20250710134112-2f96887176ff
 	github.com/sagernet/sing-mux v0.3.2
 	github.com/sagernet/sing-quic v0.5.0-beta.3
 	github.com/sagernet/sing-shadowsocks v0.2.8
 	github.com/sagernet/sing-shadowsocks2 v0.2.1
 	github.com/sagernet/sing-shadowtls v0.2.1-0.20250503051639-fcd445d33c11
-	github.com/sagernet/sing-tun v0.6.10-0.20250703121732-a0881ada3251
+	github.com/sagernet/sing-tun v0.6.10-0.20250710134146-6aeee7bc7db4
 	github.com/sagernet/sing-vmess v0.2.4-0.20250605032146-38cc72672c88
 	github.com/sagernet/smux v1.5.34-mod.2
 	github.com/sagernet/tailscale v1.80.3-mod.5

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 v0.6.12-0.20250704043954-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 v0.6.12-0.20250710134112-2f96887176ff h1:2x29M8i86PwGEGqvWI1zJWw2BiT6WRg97ELRABZo0Xc=
+github.com/sagernet/sing v0.6.12-0.20250710134112-2f96887176ff/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.3 h1:X/acRNsqQNfDlmwE7SorHfaZiny5e67hqIzM/592ric=
@@ -180,8 +180,8 @@ github.com/sagernet/sing-shadowsocks2 v0.2.1 h1:dWV9OXCeFPuYGHb6IRqlSptVnSzOelnq
 github.com/sagernet/sing-shadowsocks2 v0.2.1/go.mod h1:RnXS0lExcDAovvDeniJ4IKa2IuChrdipolPYWBv9hWQ=
 github.com/sagernet/sing-shadowtls v0.2.1-0.20250503051639-fcd445d33c11 h1:tK+75l64tm9WvEFrYRE1t0YxoFdWQqw/h7Uhzj0vJ+w=
 github.com/sagernet/sing-shadowtls v0.2.1-0.20250503051639-fcd445d33c11/go.mod h1:sWqKnGlMipCHaGsw1sTTlimyUpgzP4WP3pjhCsYt9oA=
-github.com/sagernet/sing-tun v0.6.10-0.20250703121732-a0881ada3251 h1:eH9naJXvyF/DZDk0V1SYkL6ypYD+A1tUFWLcT7PRezg=
-github.com/sagernet/sing-tun v0.6.10-0.20250703121732-a0881ada3251/go.mod h1:fisFCbC4Vfb6HqQNcwPJi2CDK2bf0Xapyz3j3t4cnHE=
+github.com/sagernet/sing-tun v0.6.10-0.20250710134146-6aeee7bc7db4 h1:OCGg2SecHgMhs+juCLoYAujZrpwWCy0/f7wF6KEF4EU=
+github.com/sagernet/sing-tun v0.6.10-0.20250710134146-6aeee7bc7db4/go.mod h1:fisFCbC4Vfb6HqQNcwPJi2CDK2bf0Xapyz3j3t4cnHE=
 github.com/sagernet/sing-vmess v0.2.4-0.20250605032146-38cc72672c88 h1:0pVm8sPOel+BoiCddW3pV3cKDKEaSioVTYDdTSKjyFI=
 github.com/sagernet/sing-vmess v0.2.4-0.20250605032146-38cc72672c88/go.mod h1:IL8Rr+EGwuqijszZkNrEFTQDKhilEpkqFqOlvdpS6/w=
 github.com/sagernet/smux v1.5.34-mod.2 h1:gkmBjIjlJ2zQKpLigOkFur5kBKdV6bNRoFu2WkltRQ4=

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, bufio.DefaultIncreaseBufferAfter)
+	_, err := bufio.CopyWithCounters(destinationWriter, sourceReader, source, readCounters, writeCounters, bufio.DefaultIncreaseBufferAfter, bufio.DefaultBatchSize)
 	if err != nil {
 		common.Close(source, destination)
 	} else if duplexDst, isDuplex := destination.(N.WriteCloser); isDuplex {