Make dedicated methods for data operations in PacketBuffer

One of the preparation to decouple underlying buffer implementation.
There are still some methods that tie to VectorisedView, and they will be
changed gradually in later CLs.

This CL also introduce a new ICMPv6ChecksumParams to replace long list of
parameters when calling ICMPv6Checksum, aiming to be more descriptive.

PiperOrigin-RevId: 360778149

3 files changed, 7 insertions, 7 deletions

diff --git a/pkg/tcpip/link/fdbased/endpoint.go b/pkg/tcpip/link/fdbased/endpoint.go
index 72d3f70ac..e17e2085c 100644
--- a/pkg/tcpip/link/fdbased/endpoint.go
+++ b/pkg/tcpip/link/fdbased/endpoint.go
@@ -427,7 +427,7 @@ func (e *endpoint) WritePacket(r stack.RouteInfo, gso *stack.GSO, protocol tcpip
 				vnetHdr.csumStart = header.EthernetMinimumSize + gso.L3HdrLen
 				vnetHdr.csumOffset = gso.CsumOffset
 			}
-			if gso.Type != stack.GSONone && uint16(pkt.Data.Size()) > gso.MSS {
+			if gso.Type != stack.GSONone && uint16(pkt.Data().Size()) > gso.MSS {
 				switch gso.Type {
 				case stack.GSOTCPv4:
 					vnetHdr.gsoType = _VIRTIO_NET_HDR_GSO_TCPV4
@@ -468,7 +468,7 @@ func (e *endpoint) sendBatch(batchFD int, batch []*stack.PacketBuffer) (int, tcp
 					vnetHdr.csumStart = header.EthernetMinimumSize + pkt.GSOOptions.L3HdrLen
 					vnetHdr.csumOffset = pkt.GSOOptions.CsumOffset
 				}
-				if pkt.GSOOptions.Type != stack.GSONone && uint16(pkt.Data.Size()) > pkt.GSOOptions.MSS {
+				if pkt.GSOOptions.Type != stack.GSONone && uint16(pkt.Data().Size()) > pkt.GSOOptions.MSS {
 					switch pkt.GSOOptions.Type {
 					case stack.GSOTCPv4:
 						vnetHdr.gsoType = _VIRTIO_NET_HDR_GSO_TCPV4
diff --git a/pkg/tcpip/link/fdbased/endpoint_test.go b/pkg/tcpip/link/fdbased/endpoint_test.go
index 358a030d2..1e40f3fef 100644
--- a/pkg/tcpip/link/fdbased/endpoint_test.go
+++ b/pkg/tcpip/link/fdbased/endpoint_test.go
@@ -67,7 +67,7 @@ func checkPacketInfoEqual(t *testing.T, got, want packetInfo) {
 				LinkHeader:      pk.LinkHeader().View(),
 				NetworkHeader:   pk.NetworkHeader().View(),
 				TransportHeader: pk.TransportHeader().View(),
-				Data:            pk.Data.ToView(),
+				Data:            pk.Data().AsRange().ToOwnedView(),
 			}
 		}),
 	); diff != "" {
@@ -616,8 +616,8 @@ func TestDispatchPacketFormat(t *testing.T) {
 			if got, want := pkt.LinkHeader().View().Size(), header.EthernetMinimumSize; got != want {
 				t.Errorf("pkt.LinkHeader().View().Size() = %d, want %d", got, want)
 			}
-			if got, want := pkt.Data.Size(), 4; got != want {
-				t.Errorf("pkt.Data.Size() = %d, want %d", got, want)
+			if got, want := pkt.Data().Size(), 4; got != want {
+				t.Errorf("pkt.Data().Size() = %d, want %d", got, want)
 			}
 		})
 	}
diff --git a/pkg/tcpip/link/fdbased/packet_dispatchers.go b/pkg/tcpip/link/fdbased/packet_dispatchers.go
index 736871d1c..46df87f44 100644
--- a/pkg/tcpip/link/fdbased/packet_dispatchers.go
+++ b/pkg/tcpip/link/fdbased/packet_dispatchers.go
@@ -165,7 +165,7 @@ func (d *readVDispatcher) dispatch() (bool, tcpip.Error) {
 		// We don't get any indication of what the packet is, so try to guess
 		// if it's an IPv4 or IPv6 packet.
 		// IP version information is at the first octet, so pulling up 1 byte.
-		h, ok := pkt.Data.PullUp(1)
+		h, ok := pkt.Data().PullUp(1)
 		if !ok {
 			return true, nil
 		}
@@ -270,7 +270,7 @@ func (d *recvMMsgDispatcher) dispatch() (bool, tcpip.Error) {
 			// We don't get any indication of what the packet is, so try to guess
 			// if it's an IPv4 or IPv6 packet.
 			// IP version information is at the first octet, so pulling up 1 byte.
-			h, ok := pkt.Data.PullUp(1)
+			h, ok := pkt.Data().PullUp(1)
 			if !ok {
 				// Skip this packet.
 				continue