🫛 conn: add UDP GRO option

database64128 · Sep 26, 2024 · 5dab961 · 5dab961
1 parent aaf9f82
commit 5dab961
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Showing 4 changed files with 29 additions and 0 deletions.
diff --git a/conn/conn.go b/conn/conn.go
@@ -138,6 +138,11 @@ type ListenerSocketOptions struct {
 	// Available on platforms supported by Go std's MPTCP implementation.
 	MultipathTCP bool
 
+	// UDPGenericReceiveOffload enables UDP Generic Receive Offload (GRO) on the listener.
+	//
+	// Available on Linux and Windows.
+	UDPGenericReceiveOffload bool
+
 	// ReceivePacketInfo enables the reception of packet information control messages on the listener.
 	//
 	// Available on Linux, macOS, and Windows.

diff --git a/conn/conn_linux.go b/conn/conn_linux.go
@@ -51,6 +51,10 @@ func setTCPUserTimeout(fd, msecs int) error {
 	return nil
 }
 
+func setUDPGenericReceiveOffload(fd int) {
+	_ = unix.SetsockoptInt(fd, unix.IPPROTO_UDP, unix.UDP_GRO, 1)
+}
+
 func setTransparent(fd int, network string) error {
 	switch network {
 	case "tcp4", "udp4":
@@ -162,6 +166,7 @@ func (lso ListenerSocketOptions) buildSetFns() setFuncSlice {
 		appendSetReusePortFunc(lso.ReusePort).
 		appendSetTransparentFunc(lso.Transparent).
 		appendSetPMTUDFunc(lso.PathMTUDiscovery).
+		appendSetUDPGenericReceiveOffloadFunc(lso.UDPGenericReceiveOffload).
 		appendSetRecvPktinfoFunc(lso.ReceivePacketInfo).
 		appendSetRecvOrigDstAddrFunc(lso.ReceiveOriginalDestAddr)
 }

diff --git a/conn/conn_udpgro.go b/conn/conn_udpgro.go
@@ -0,0 +1,13 @@
+//go:build linux || windows
+
+package conn
+
+func (fns setFuncSlice) appendSetUDPGenericReceiveOffloadFunc(gro bool) setFuncSlice {
+	if gro {
+		return append(fns, func(fd int, _ string) error {
+			setUDPGenericReceiveOffload(fd)
+			return nil
+		})
+	}
+	return fns
+}
diff --git a/conn/conn_windows.go b/conn/conn_windows.go
@@ -41,6 +41,11 @@ func setPMTUD(fd int, network string) error {
 	return nil
 }
 
+func setUDPGenericReceiveOffload(fd int) {
+	// Both quinn and msquic set this to 65535.
+	_ = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_UDP, windows.UDP_RECV_MAX_COALESCED_SIZE, 65535)
+}
+
 func setRecvPktinfo(fd int, network string) error {
 	// Set IP_PKTINFO for both v4 and v6.
 	if err := windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IP, windows.IP_PKTINFO, 1); err != nil {
@@ -63,6 +68,7 @@ func setRecvPktinfo(fd int, network string) error {
 func (lso ListenerSocketOptions) buildSetFns() setFuncSlice {
 	return setFuncSlice{}.
 		appendSetPMTUDFunc(lso.PathMTUDiscovery).
+		appendSetUDPGenericReceiveOffloadFunc(lso.UDPGenericReceiveOffload).
 		appendSetRecvPktinfoFunc(lso.ReceivePacketInfo)
 }