netstack: don't verify IPv4 checksum when offload is enabled

There's no reason to check it.

PiperOrigin-RevId: 487012436

pkg/tcpip/network/ipv4/ipv4.go

@@ -835,7 +835,7 @@ func (e *endpoint) handleLocalPacket(pkt stack.PacketBufferPtr, canSkipRXChecksu
 
 	pkt = pkt.CloneToInbound()
 	defer pkt.DecRef()
-	pkt.RXTransportChecksumValidated = canSkipRXChecksum
+	pkt.RXChecksumValidated = canSkipRXChecksum
 
 	h, ok := e.protocol.parseAndValidate(pkt)
 	if !ok {
@@ -1705,7 +1705,7 @@ func (p *protocol) parseAndValidate(pkt stack.PacketBufferPtr) (header.IPv4, boo
 		return nil, false
 	}
 
-	if !h.IsChecksumValid() {
+	if !pkt.RXChecksumValidated && !h.IsChecksumValid() {
 		return nil, false
 	}
 

pkg/tcpip/network/ipv6/ipv6.go

@@ -1101,7 +1101,7 @@ func (e *endpoint) handleLocalPacket(pkt stack.PacketBufferPtr, canSkipRXChecksu
 
 	pkt = pkt.CloneToInbound()
 	defer pkt.DecRef()
-	pkt.RXTransportChecksumValidated = canSkipRXChecksum
+	pkt.RXChecksumValidated = canSkipRXChecksum
 
 	hView, ok := e.protocol.parseAndValidate(pkt)
 	if !ok {

pkg/tcpip/stack/conntrack.go

@@ -530,7 +530,7 @@ func (ct *ConnTrack) getConnAndUpdate(pkt PacketBufferPtr, skipChecksumValidatio
 				uint16(pkt.Data().Size()),
 				tid.srcAddr,
 				tid.dstAddr,
-				pkt.RXTransportChecksumValidated || skipChecksumValidation)
+				pkt.RXChecksumValidated || skipChecksumValidation)
 			if !csumValid || !ok {
 				return nil
 			}
@@ -542,7 +542,7 @@ func (ct *ConnTrack) getConnAndUpdate(pkt PacketBufferPtr, skipChecksumValidatio
 				pkt.NetworkProtocolNumber,
 				tid.srcAddr,
 				tid.dstAddr,
-				pkt.RXTransportChecksumValidated || skipChecksumValidation)
+				pkt.RXChecksumValidated || skipChecksumValidation)
 			if !lengthValid || !csumValid {
 				return nil
 			}

pkg/tcpip/stack/nic.go

@@ -731,7 +731,7 @@ func (n *nic) DeliverNetworkPacket(protocol tcpip.NetworkProtocolNumber, pkt Pac
 		return
 	}
 
-	pkt.RXTransportChecksumValidated = n.NetworkLinkEndpoint.Capabilities()&CapabilityRXChecksumOffload != 0
+	pkt.RXChecksumValidated = n.NetworkLinkEndpoint.Capabilities()&CapabilityRXChecksumOffload != 0
 
 	networkEndpoint.HandlePacket(pkt)
 }

pkg/tcpip/stack/packet_buffer.go

@@ -162,9 +162,9 @@ type packetBuffer struct {
 	// NICID is the ID of the last interface the network packet was handled at.
 	NICID tcpip.NICID
 
-	// RXTransportChecksumValidated indicates that transport checksum verification
-	// may be safely skipped.
-	RXTransportChecksumValidated bool
+	// RXChecksumValidated indicates that checksum verification may be
+	// safely skipped.
+	RXChecksumValidated bool
 
 	// NetworkPacketInfo holds an incoming packet's network-layer information.
 	NetworkPacketInfo NetworkPacketInfo
@@ -390,7 +390,7 @@ func (pk PacketBufferPtr) Clone() PacketBufferPtr {
 	newPk.TransportProtocolNumber = pk.TransportProtocolNumber
 	newPk.PktType = pk.PktType
 	newPk.NICID = pk.NICID
-	newPk.RXTransportChecksumValidated = pk.RXTransportChecksumValidated
+	newPk.RXChecksumValidated = pk.RXChecksumValidated
 	newPk.NetworkPacketInfo = pk.NetworkPacketInfo
 	newPk.tuple = pk.tuple
 	newPk.InitRefs()

pkg/tcpip/transport/tcp/segment.go

@@ -101,7 +101,7 @@ func newIncomingSegment(id stack.TransportEndpointID, clock tcpip.Clock, pkt sta
 		uint16(pkt.Data().Size()),
 		netHdr.SourceAddress(),
 		netHdr.DestinationAddress(),
-		pkt.RXTransportChecksumValidated)
+		pkt.RXChecksumValidated)
 	if !ok {
 		return nil, fmt.Errorf("header data offset does not respect size constraints: %d < offset < %d, got offset=%d", header.TCPMinimumSize, len(hdr), hdr.DataOffset())
 	}
@@ -119,7 +119,7 @@ func newIncomingSegment(id stack.TransportEndpointID, clock tcpip.Clock, pkt sta
 	s.pkt = pkt.IncRef()
 	s.csumValid = csumValid
 
-	if !s.pkt.RXTransportChecksumValidated {
+	if !s.pkt.RXChecksumValidated {
 		s.csum = csum
 	}
 	return s, nil

pkg/tcpip/transport/udp/endpoint.go

@@ -913,7 +913,7 @@ func (e *endpoint) HandlePacket(id stack.TransportEndpointID, pkt stack.PacketBu
 		pkt.NetworkProtocolNumber,
 		netHdr.SourceAddress(),
 		netHdr.DestinationAddress(),
-		pkt.RXTransportChecksumValidated)
+		pkt.RXChecksumValidated)
 	if !lengthValid {
 		// Malformed packet.
 		e.stack.Stats().UDP.MalformedPacketsReceived.Increment()

pkg/tcpip/transport/udp/protocol.go

@@ -87,7 +87,7 @@ func (p *protocol) HandleUnknownDestinationPacket(id stack.TransportEndpointID,
 		pkt.NetworkProtocolNumber,
 		netHdr.SourceAddress(),
 		netHdr.DestinationAddress(),
-		pkt.RXTransportChecksumValidated)
+		pkt.RXChecksumValidated)
 	if !lengthValid {
 		p.stack.Stats().UDP.MalformedPacketsReceived.Increment()
 		return stack.UnknownDestinationPacketMalformed