Merge release-20210301.0-12-g1cd76d958 (automated)

9 files changed, 118 insertions, 80 deletions

diff --git a/pkg/tcpip/network/internal/fragmentation/fragmentation.go b/pkg/tcpip/network/internal/fragmentation/fragmentation.go
index 243738951..5168f5361 100644
--- a/pkg/tcpip/network/internal/fragmentation/fragmentation.go
+++ b/pkg/tcpip/network/internal/fragmentation/fragmentation.go
@@ -170,7 +170,7 @@ func (f *Fragmentation) Process(
 		return nil, 0, false, fmt.Errorf("fragment size=%d bytes is not a multiple of block size=%d on non-final fragment: %w", fragmentSize, f.blockSize, ErrInvalidArgs)
 	}
 
-	if l := pkt.Data.Size(); l != int(fragmentSize) {
+	if l := pkt.Data().Size(); l != int(fragmentSize) {
 		return nil, 0, false, fmt.Errorf("got fragment size=%d bytes not equal to the expected fragment size=%d bytes (first=%d last=%d): %w", l, fragmentSize, first, last, ErrInvalidArgs)
 	}
 
@@ -293,7 +293,7 @@ func MakePacketFragmenter(pkt *stack.PacketBuffer, fragmentPayloadLen uint32, re
 	// these headers.
 	var fragmentableData buffer.VectorisedView
 	fragmentableData.AppendView(pkt.TransportHeader().View())
-	fragmentableData.Append(pkt.Data)
+	fragmentableData.Append(pkt.Data().ExtractVV())
 	fragmentCount := (uint32(fragmentableData.Size()) + fragmentPayloadLen - 1) / fragmentPayloadLen
 
 	return PacketFragmenter{
@@ -323,7 +323,7 @@ func (pf *PacketFragmenter) BuildNextFragment() (*stack.PacketBuffer, int, int,
 	})
 
 	// Copy data for the fragment.
-	copied := pf.data.ReadToVV(&fragPkt.Data, pf.fragmentPayloadLen)
+	copied := fragPkt.Data().ReadFromVV(&pf.data, pf.fragmentPayloadLen)
 
 	offset := pf.fragmentOffset
 	pf.fragmentOffset += copied
diff --git a/pkg/tcpip/network/internal/fragmentation/reassembler.go b/pkg/tcpip/network/internal/fragmentation/reassembler.go
index 933d63d32..90075a70c 100644
--- a/pkg/tcpip/network/internal/fragmentation/reassembler.go
+++ b/pkg/tcpip/network/internal/fragmentation/reassembler.go
@@ -167,8 +167,8 @@ func (r *reassembler) process(first, last uint16, more bool, proto uint8, pkt *s
 
 	resPkt := r.holes[0].pkt
 	for i := 1; i < len(r.holes); i++ {
-		fragPkt := r.holes[i].pkt
-		fragPkt.Data.ReadToVV(&resPkt.Data, fragPkt.Data.Size())
+		fragData := r.holes[i].pkt.Data()
+		resPkt.Data().ReadFromData(fragData, fragData.Size())
 	}
 	return resPkt, r.proto, true, memConsumed, nil
 }
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 5bf7809e8..deb104837 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -137,7 +137,7 @@ func (e *endpoint) checkLocalAddress(addr tcpip.Address) bool {
 // is used to find out which transport endpoint must be notified about the ICMP
 // packet. We only expect the payload, not the enclosing ICMP packet.
 func (e *endpoint) handleControl(errInfo stack.TransportError, pkt *stack.PacketBuffer) {
-	h, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
+	h, ok := pkt.Data().PullUp(header.IPv4MinimumSize)
 	if !ok {
 		return
 	}
@@ -156,7 +156,7 @@ func (e *endpoint) handleControl(errInfo stack.TransportError, pkt *stack.Packet
 	}
 
 	hlen := int(hdr.HeaderLength())
-	if pkt.Data.Size() < hlen || hdr.FragmentOffset() != 0 {
+	if pkt.Data().Size() < hlen || hdr.FragmentOffset() != 0 {
 		// We won't be able to handle this if it doesn't contain the
 		// full IPv4 header, or if it's a fragment not at offset 0
 		// (because it won't have the transport header).
@@ -164,7 +164,7 @@ func (e *endpoint) handleControl(errInfo stack.TransportError, pkt *stack.Packet
 	}
 
 	// Skip the ip header, then deliver the error.
-	pkt.Data.TrimFront(hlen)
+	pkt.Data().TrimFront(hlen)
 	p := hdr.TransportProtocol()
 	e.dispatcher.DeliverTransportError(srcAddr, hdr.DestinationAddress(), ProtocolNumber, p, errInfo, pkt)
 }
@@ -174,7 +174,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) {
 	// TODO(gvisor.dev/issue/170): ICMP packets don't have their
 	// TransportHeader fields set. See icmp/protocol.go:protocol.Parse for a
 	// full explanation.
-	v, ok := pkt.Data.PullUp(header.ICMPv4MinimumSize)
+	v, ok := pkt.Data().PullUp(header.ICMPv4MinimumSize)
 	if !ok {
 		received.invalid.Increment()
 		return
@@ -182,7 +182,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) {
 	h := header.ICMPv4(v)
 
 	// Only do in-stack processing if the checksum is correct.
-	if header.ChecksumVV(pkt.Data, 0 /* initial */) != 0xffff {
+	if pkt.Data().AsRange().Checksum() != 0xffff {
 		received.invalid.Increment()
 		// It's possible that a raw socket expects to receive this regardless
 		// of checksum errors. If it's an echo request we know it's safe because
@@ -253,7 +253,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) {
 		// TODO(gvisor.dev/issue/4399): The copy may not be needed if there are no
 		// waiting endpoints. Consider moving responsibility for doing the copy to
 		// DeliverTransportPacket so that is is only done when needed.
-		replyData := pkt.Data.ToOwnedView()
+		replyData := pkt.Data().AsRange().ToOwnedView()
 		ipHdr := header.IPv4(pkt.NetworkHeader().View())
 		localAddressBroadcast := pkt.NetworkPacketInfo.LocalAddressBroadcast
 
@@ -336,7 +336,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) {
 	case header.ICMPv4DstUnreachable:
 		received.dstUnreachable.Increment()
 
-		pkt.Data.TrimFront(header.ICMPv4MinimumSize)
+		pkt.Data().TrimFront(header.ICMPv4MinimumSize)
 		switch h.Code() {
 		case header.ICMPv4HostUnreachable:
 			e.handleControl(&icmpv4DestinationHostUnreachableSockError{}, pkt)
@@ -571,7 +571,7 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip
 		return nil
 	}
 
-	payloadLen := len(origIPHdr) + transportHeader.Size() + pkt.Data.Size()
+	payloadLen := len(origIPHdr) + transportHeader.Size() + pkt.Data().Size()
 	if payloadLen > available {
 		payloadLen = available
 	}
@@ -586,8 +586,11 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip
 	newHeader := append(buffer.View(nil), origIPHdr...)
 	newHeader = append(newHeader, transportHeader...)
 	payload := newHeader.ToVectorisedView()
-	payload.AppendView(pkt.Data.ToView())
-	payload.CapLength(payloadLen)
+	if dataCap := payloadLen - payload.Size(); dataCap > 0 {
+		payload.AppendView(pkt.Data().AsRange().Capped(dataCap).ToOwnedView())
+	} else {
+		payload.CapLength(payloadLen)
+	}
 
 	icmpPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
 		ReserveHeaderBytes: int(route.MaxHeaderLength()) + header.ICMPv4MinimumSize,
@@ -623,7 +626,7 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip
 	default:
 		panic(fmt.Sprintf("unsupported ICMP type %T", reason))
 	}
-	icmpHdr.SetChecksum(header.ICMPv4Checksum(icmpHdr, icmpPkt.Data))
+	icmpHdr.SetChecksum(header.ICMPv4Checksum(icmpHdr, icmpPkt.Data().AsRange().Checksum()))
 
 	if err := route.WritePacket(
 		nil, /* gso */
diff --git a/pkg/tcpip/network/ipv4/igmp.go b/pkg/tcpip/network/ipv4/igmp.go
index 0a15ae897..f3fc1c87e 100644
--- a/pkg/tcpip/network/ipv4/igmp.go
+++ b/pkg/tcpip/network/ipv4/igmp.go
@@ -197,7 +197,7 @@ func (igmp *igmpState) isPacketValidLocked(pkt *stack.PacketBuffer, messageType
 // Precondition: igmp.ep.mu must be locked.
 func (igmp *igmpState) handleIGMP(pkt *stack.PacketBuffer, hasRouterAlertOption bool) {
 	received := igmp.ep.stats.igmp.packetsReceived
-	headerView, ok := pkt.Data.PullUp(header.IGMPMinimumSize)
+	headerView, ok := pkt.Data().PullUp(header.IGMPMinimumSize)
 	if !ok {
 		received.invalid.Increment()
 		return
@@ -210,7 +210,7 @@ func (igmp *igmpState) handleIGMP(pkt *stack.PacketBuffer, hasRouterAlertOption
 	//   same set of octets, including the checksum field. If the result
 	//   is all 1 bits (-0 in 1's complement arithmetic), the check
 	//   succeeds.
-	if header.ChecksumVV(pkt.Data, 0 /* initial */) != 0xFFFF {
+	if pkt.Data().AsRange().Checksum() != 0xFFFF {
 		received.checksumErrors.Increment()
 		return
 	}
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 4a429ea6c..cabe274d6 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -492,7 +492,7 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
 func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBuffer) tcpip.Error {
 	// The packet already has an IP header, but there are a few required
 	// checks.
-	h, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
+	h, ok := pkt.Data().PullUp(header.IPv4MinimumSize)
 	if !ok {
 		return &tcpip.ErrMalformedHeader{}
 	}
@@ -502,14 +502,14 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBu
 		return &tcpip.ErrMalformedHeader{}
 	}
 
-	h, ok = pkt.Data.PullUp(int(hdrLen))
+	h, ok = pkt.Data().PullUp(int(hdrLen))
 	if !ok {
 		return &tcpip.ErrMalformedHeader{}
 	}
 	ip := header.IPv4(h)
 
 	// Always set the total length.
-	pktSize := pkt.Data.Size()
+	pktSize := pkt.Data().Size()
 	ip.SetTotalLength(uint16(pktSize))
 
 	// Set the source address when zero.
@@ -687,7 +687,7 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 	stats := e.stats
 
 	h := header.IPv4(pkt.NetworkHeader().View())
-	if !h.IsValid(pkt.Data.Size() + pkt.NetworkHeader().View().Size() + pkt.TransportHeader().View().Size()) {
+	if !h.IsValid(pkt.Data().Size() + pkt.NetworkHeader().View().Size() + pkt.TransportHeader().View().Size()) {
 		stats.ip.MalformedPacketsReceived.Increment()
 		return
 	}
@@ -765,7 +765,7 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 	}
 
 	if h.More() || h.FragmentOffset() != 0 {
-		if pkt.Data.Size()+pkt.TransportHeader().View().Size() == 0 {
+		if pkt.Data().Size()+pkt.TransportHeader().View().Size() == 0 {
 			// Drop the packet as it's marked as a fragment but has
 			// no payload.
 			stats.ip.MalformedPacketsReceived.Increment()
@@ -793,10 +793,10 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 		// maximum payload size.
 		//
 		// Note that this addition doesn't overflow even on 32bit architecture
-		// because pkt.Data.Size() should not exceed 65535 (the max IP datagram
+		// because pkt.Data().Size() should not exceed 65535 (the max IP datagram
 		// size). Otherwise the packet would've been rejected as invalid before
 		// reaching here.
-		if int(start)+pkt.Data.Size() > header.IPv4MaximumPayloadSize {
+		if int(start)+pkt.Data().Size() > header.IPv4MaximumPayloadSize {
 			stats.ip.MalformedPacketsReceived.Increment()
 			stats.ip.MalformedFragmentsReceived.Increment()
 			return
@@ -813,7 +813,7 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 				Protocol:    proto,
 			},
 			start,
-			start+uint16(pkt.Data.Size())-1,
+			start+uint16(pkt.Data().Size())-1,
 			h.More(),
 			proto,
 			pkt,
@@ -831,7 +831,7 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 
 		// The reassembler doesn't take care of fixing up the header, so we need
 		// to do it here.
-		h.SetTotalLength(uint16(pkt.Data.Size() + len((h))))
+		h.SetTotalLength(uint16(pkt.Data().Size() + len((h))))
 		h.SetFlagsFragmentOffset(0, 0)
 	}
 	stats.ip.PacketsDelivered.Increment()
@@ -1186,7 +1186,7 @@ func calculateNetworkMTU(linkMTU, networkHeaderSize uint32) (uint32, tcpip.Error
 }
 
 func packetMustBeFragmented(pkt *stack.PacketBuffer, networkMTU uint32, gso *stack.GSO) bool {
-	payload := pkt.TransportHeader().View().Size() + pkt.Data.Size()
+	payload := pkt.TransportHeader().View().Size() + pkt.Data().Size()
 	return (gso == nil || gso.Type == stack.GSONone) && uint32(payload) > networkMTU
 }
 
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index 5f44ab317..e80e681da 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -18,7 +18,6 @@ import (
 	"fmt"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
@@ -165,7 +164,7 @@ func (e *endpoint) checkLocalAddress(addr tcpip.Address) bool {
 // used to find out which transport endpoint must be notified about the ICMP
 // packet.
 func (e *endpoint) handleControl(transErr stack.TransportError, pkt *stack.PacketBuffer) {
-	h, ok := pkt.Data.PullUp(header.IPv6MinimumSize)
+	h, ok := pkt.Data().PullUp(header.IPv6MinimumSize)
 	if !ok {
 		return
 	}
@@ -184,10 +183,10 @@ func (e *endpoint) handleControl(transErr stack.TransportError, pkt *stack.Packe
 
 	// Skip the IP header, then handle the fragmentation header if there
 	// is one.
-	pkt.Data.TrimFront(header.IPv6MinimumSize)
+	pkt.Data().TrimFront(header.IPv6MinimumSize)
 	p := hdr.TransportProtocol()
 	if p == header.IPv6FragmentHeader {
-		f, ok := pkt.Data.PullUp(header.IPv6FragmentHeaderSize)
+		f, ok := pkt.Data().PullUp(header.IPv6FragmentHeaderSize)
 		if !ok {
 			return
 		}
@@ -200,7 +199,7 @@ func (e *endpoint) handleControl(transErr stack.TransportError, pkt *stack.Packe
 
 		// Skip fragmentation header and find out the actual protocol
 		// number.
-		pkt.Data.TrimFront(header.IPv6FragmentHeaderSize)
+		pkt.Data().TrimFront(header.IPv6FragmentHeaderSize)
 		p = fragHdr.TransportProtocol()
 	}
 
@@ -268,7 +267,7 @@ func isMLDValid(pkt *stack.PacketBuffer, iph header.IPv6, routerAlert *header.IP
 	if routerAlert == nil || routerAlert.Value != header.IPv6RouterAlertMLD {
 		return false
 	}
-	if pkt.Data.Size() < header.ICMPv6HeaderSize+header.MLDMinimumSize {
+	if pkt.Data().Size() < header.ICMPv6HeaderSize+header.MLDMinimumSize {
 		return false
 	}
 	if iph.HopLimit() != header.MLDHopLimit {
@@ -285,7 +284,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 	received := e.stats.icmp.packetsReceived
 	// TODO(gvisor.dev/issue/170): ICMP packets don't have their TransportHeader
 	// fields set. See icmp/protocol.go:protocol.Parse for a full explanation.
-	v, ok := pkt.Data.PullUp(header.ICMPv6HeaderSize)
+	v, ok := pkt.Data().PullUp(header.ICMPv6HeaderSize)
 	if !ok {
 		received.invalid.Increment()
 		return
@@ -296,11 +295,14 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 	dstAddr := iph.DestinationAddress()
 
 	// Validate ICMPv6 checksum before processing the packet.
-	//
-	// This copy is used as extra payload during the checksum calculation.
-	payload := pkt.Data.Clone(nil)
-	payload.TrimFront(len(h))
-	if got, want := h.Checksum(), header.ICMPv6Checksum(h, srcAddr, dstAddr, payload); got != want {
+	payload := pkt.Data().AsRange().SubRange(len(h))
+	if got, want := h.Checksum(), header.ICMPv6Checksum(header.ICMPv6ChecksumParams{
+		Header:      h,
+		Src:         srcAddr,
+		Dst:         dstAddr,
+		PayloadCsum: payload.Checksum(),
+		PayloadLen:  payload.Size(),
+	}); got != want {
 		received.invalid.Increment()
 		return
 	}
@@ -320,12 +322,12 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 	switch icmpType := h.Type(); icmpType {
 	case header.ICMPv6PacketTooBig:
 		received.packetTooBig.Increment()
-		hdr, ok := pkt.Data.PullUp(header.ICMPv6PacketTooBigMinimumSize)
+		hdr, ok := pkt.Data().PullUp(header.ICMPv6PacketTooBigMinimumSize)
 		if !ok {
 			received.invalid.Increment()
 			return
 		}
-		pkt.Data.TrimFront(header.ICMPv6PacketTooBigMinimumSize)
+		pkt.Data().TrimFront(header.ICMPv6PacketTooBigMinimumSize)
 		networkMTU, err := calculateNetworkMTU(header.ICMPv6(hdr).MTU(), header.IPv6MinimumSize)
 		if err != nil {
 			networkMTU = 0
@@ -334,12 +336,12 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 
 	case header.ICMPv6DstUnreachable:
 		received.dstUnreachable.Increment()
-		hdr, ok := pkt.Data.PullUp(header.ICMPv6DstUnreachableMinimumSize)
+		hdr, ok := pkt.Data().PullUp(header.ICMPv6DstUnreachableMinimumSize)
 		if !ok {
 			received.invalid.Increment()
 			return
 		}
-		pkt.Data.TrimFront(header.ICMPv6DstUnreachableMinimumSize)
+		pkt.Data().TrimFront(header.ICMPv6DstUnreachableMinimumSize)
 		switch header.ICMPv6(hdr).Code() {
 		case header.ICMPv6NetworkUnreachable:
 			e.handleControl(&icmpv6DestinationNetworkUnreachableSockError{}, pkt)
@@ -348,16 +350,16 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 		}
 	case header.ICMPv6NeighborSolicit:
 		received.neighborSolicit.Increment()
-		if !isNDPValid() || pkt.Data.Size() < header.ICMPv6NeighborSolicitMinimumSize {
+		if !isNDPValid() || pkt.Data().Size() < header.ICMPv6NeighborSolicitMinimumSize {
 			received.invalid.Increment()
 			return
 		}
 
 		// The remainder of payload must be only the neighbor solicitation, so
-		// payload.ToView() always returns the solicitation. Per RFC 6980 section 5,
+		// payload.AsView() always returns the solicitation. Per RFC 6980 section 5,
 		// NDP messages cannot be fragmented. Also note that in the common case NDP
-		// datagrams are very small and ToView() will not incur allocations.
-		ns := header.NDPNeighborSolicit(payload.ToView())
+		// datagrams are very small and AsView() will not incur allocations.
+		ns := header.NDPNeighborSolicit(payload.AsView())
 		targetAddr := ns.TargetAddress()
 
 		// As per RFC 4861 section 4.3, the Target Address MUST NOT be a multicast
@@ -529,7 +531,11 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 		na.SetOverrideFlag(true)
 		na.SetTargetAddress(targetAddr)
 		na.Options().Serialize(optsSerializer)
-		packet.SetChecksum(header.ICMPv6Checksum(packet, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{}))
+		packet.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{
+			Header: packet,
+			Src:    r.LocalAddress,
+			Dst:    r.RemoteAddress,
+		}))
 
 		// RFC 4861 Neighbor Discovery for IP version 6 (IPv6)
 		//
@@ -545,16 +551,16 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 
 	case header.ICMPv6NeighborAdvert:
 		received.neighborAdvert.Increment()
-		if !isNDPValid() || pkt.Data.Size() < header.ICMPv6NeighborAdvertMinimumSize {
+		if !isNDPValid() || pkt.Data().Size() < header.ICMPv6NeighborAdvertMinimumSize {
 			received.invalid.Increment()
 			return
 		}
 
 		// The remainder of payload must be only the neighbor advertisement, so
-		// payload.ToView() always returns the advertisement. Per RFC 6980 section
+		// payload.AsView() always returns the advertisement. Per RFC 6980 section
 		// 5, NDP messages cannot be fragmented. Also note that in the common case
-		// NDP datagrams are very small and ToView() will not incur allocations.
-		na := header.NDPNeighborAdvert(payload.ToView())
+		// NDP datagrams are very small and AsView() will not incur allocations.
+		na := header.NDPNeighborAdvert(payload.AsView())
 		targetAddr := na.TargetAddress()
 
 		e.dad.mu.Lock()
@@ -657,13 +663,20 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 
 		replyPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
 			ReserveHeaderBytes: int(r.MaxHeaderLength()) + header.ICMPv6EchoMinimumSize,
-			Data:               pkt.Data,
+			Data:               pkt.Data().ExtractVV(),
 		})
-		packet := header.ICMPv6(replyPkt.TransportHeader().Push(header.ICMPv6EchoMinimumSize))
+		icmp := header.ICMPv6(replyPkt.TransportHeader().Push(header.ICMPv6EchoMinimumSize))
 		pkt.TransportProtocolNumber = header.ICMPv6ProtocolNumber
-		copy(packet, icmpHdr)
-		packet.SetType(header.ICMPv6EchoReply)
-		packet.SetChecksum(header.ICMPv6Checksum(packet, r.LocalAddress, r.RemoteAddress, pkt.Data))
+		copy(icmp, icmpHdr)
+		icmp.SetType(header.ICMPv6EchoReply)
+		dataRange := replyPkt.Data().AsRange()
+		icmp.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{
+			Header:      icmp,
+			Src:         r.LocalAddress,
+			Dst:         r.RemoteAddress,
+			PayloadCsum: dataRange.Checksum(),
+			PayloadLen:  dataRange.Size(),
+		}))
 		if err := r.WritePacket(nil /* gso */, stack.NetworkHeaderParams{
 			Protocol: header.ICMPv6ProtocolNumber,
 			TTL:      r.DefaultTTL(),
@@ -676,7 +689,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 
 	case header.ICMPv6EchoReply:
 		received.echoReply.Increment()
-		if pkt.Data.Size() < header.ICMPv6EchoMinimumSize {
+		if pkt.Data().Size() < header.ICMPv6EchoMinimumSize {
 			received.invalid.Increment()
 			return
 		}
@@ -696,7 +709,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 		//
 
 		// Is the NDP payload of sufficient size to hold a Router Solictation?
-		if !isNDPValid() || pkt.Data.Size()-header.ICMPv6HeaderSize < header.NDPRSMinimumSize {
+		if !isNDPValid() || pkt.Data().Size()-header.ICMPv6HeaderSize < header.NDPRSMinimumSize {
 			received.invalid.Increment()
 			return
 		}
@@ -710,9 +723,9 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 			return
 		}
 
-		// Note that in the common case NDP datagrams are very small and ToView()
+		// Note that in the common case NDP datagrams are very small and AsView()
 		// will not incur allocations.
-		rs := header.NDPRouterSolicit(payload.ToView())
+		rs := header.NDPRouterSolicit(payload.AsView())
 		it, err := rs.Options().Iter(false /* check */)
 		if err != nil {
 			// Options are not valid as per the wire format, silently drop the packet.
@@ -756,7 +769,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 		//
 
 		// Is the NDP payload of sufficient size to hold a Router Advertisement?
-		if !isNDPValid() || pkt.Data.Size()-header.ICMPv6HeaderSize < header.NDPRAMinimumSize {
+		if !isNDPValid() || pkt.Data().Size()-header.ICMPv6HeaderSize < header.NDPRAMinimumSize {
 			received.invalid.Increment()
 			return
 		}
@@ -770,9 +783,9 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 			return
 		}
 
-		// Note that in the common case NDP datagrams are very small and ToView()
+		// Note that in the common case NDP datagrams are very small and AsView()
 		// will not incur allocations.
-		ra := header.NDPRouterAdvert(payload.ToView())
+		ra := header.NDPRouterAdvert(payload.AsView())
 		it, err := ra.Options().Iter(false /* check */)
 		if err != nil {
 			// Options are not valid as per the wire format, silently drop the packet.
@@ -850,11 +863,11 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 		switch icmpType {
 		case header.ICMPv6MulticastListenerQuery:
 			e.mu.Lock()
-			e.mu.mld.handleMulticastListenerQuery(header.MLD(payload.ToView()))
+			e.mu.mld.handleMulticastListenerQuery(header.MLD(payload.AsView()))
 			e.mu.Unlock()
 		case header.ICMPv6MulticastListenerReport:
 			e.mu.Lock()
-			e.mu.mld.handleMulticastListenerReport(header.MLD(payload.ToView()))
+			e.mu.mld.handleMulticastListenerReport(header.MLD(payload.AsView()))
 			e.mu.Unlock()
 		case header.ICMPv6MulticastListenerDone:
 		default:
@@ -1077,13 +1090,13 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip
 	if available < header.IPv6MinimumSize {
 		return nil
 	}
-	payloadLen := network.Size() + transport.Size() + pkt.Data.Size()
+	payloadLen := network.Size() + transport.Size() + pkt.Data().Size()
 	if payloadLen > available {
 		payloadLen = available
 	}
 	payload := network.ToVectorisedView()
 	payload.AppendView(transport)
-	payload.Append(pkt.Data)
+	payload.Append(pkt.Data().ExtractVV())
 	payload.CapLength(payloadLen)
 
 	newPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
@@ -1115,7 +1128,14 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip
 	default:
 		panic(fmt.Sprintf("unsupported ICMP type %T", reason))
 	}
-	icmpHdr.SetChecksum(header.ICMPv6Checksum(icmpHdr, route.LocalAddress, route.RemoteAddress, newPkt.Data))
+	dataRange := newPkt.Data().AsRange()
+	icmpHdr.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{
+		Header:      icmpHdr,
+		Src:         route.LocalAddress,
+		Dst:         route.RemoteAddress,
+		PayloadCsum: dataRange.Checksum(),
+		PayloadLen:  dataRange.Size(),
+	}))
 	if err := route.WritePacket(
 		nil, /* gso */
 		stack.NetworkHeaderParams{
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 7638ade35..544717678 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -619,7 +619,7 @@ func addIPHeader(srcAddr, dstAddr tcpip.Address, pkt *stack.PacketBuffer, params
 }
 
 func packetMustBeFragmented(pkt *stack.PacketBuffer, networkMTU uint32, gso *stack.GSO) bool {
-	payload := pkt.TransportHeader().View().Size() + pkt.Data.Size()
+	payload := pkt.TransportHeader().View().Size() + pkt.Data().Size()
 	return (gso == nil || gso.Type == stack.GSONone) && uint32(payload) > networkMTU
 }
 
@@ -819,14 +819,14 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
 // WriteHeaderIncludedPacket implements stack.NetworkEndpoint.
 func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBuffer) tcpip.Error {
 	// The packet already has an IP header, but there are a few required checks.
-	h, ok := pkt.Data.PullUp(header.IPv6MinimumSize)
+	h, ok := pkt.Data().PullUp(header.IPv6MinimumSize)
 	if !ok {
 		return &tcpip.ErrMalformedHeader{}
 	}
 	ip := header.IPv6(h)
 
 	// Always set the payload length.
-	pktSize := pkt.Data.Size()
+	pktSize := pkt.Data().Size()
 	ip.SetPayloadLength(uint16(pktSize - header.IPv6MinimumSize))
 
 	// Set the source address when zero.
@@ -964,7 +964,7 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 	stats := e.stats.ip
 
 	h := header.IPv6(pkt.NetworkHeader().View())
-	if !h.IsValid(pkt.Data.Size() + pkt.NetworkHeader().View().Size() + pkt.TransportHeader().View().Size()) {
+	if !h.IsValid(pkt.Data().Size() + pkt.NetworkHeader().View().Size() + pkt.TransportHeader().View().Size()) {
 		stats.MalformedPacketsReceived.Increment()
 		return
 	}
@@ -993,13 +993,14 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 		return
 	}
 
+	// Create a VV to parse the packet. We don't plan to modify anything here.
 	// vv consists of:
 	// - Any IPv6 header bytes after the first 40 (i.e. extensions).
 	// - The transport header, if present.
 	// - Any other payload data.
 	vv := pkt.NetworkHeader().View()[header.IPv6MinimumSize:].ToVectorisedView()
 	vv.AppendView(pkt.TransportHeader().View())
-	vv.Append(pkt.Data)
+	vv.AppendViews(pkt.Data().Views())
 	it := header.MakeIPv6PayloadIterator(header.IPv6ExtensionHeaderIdentifier(h.NextHeader()), vv)
 
 	// iptables filtering. All packets that reach here are intended for
@@ -1257,7 +1258,9 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 				// have more extension headers in the reassembled payload, as per RFC
 				// 8200 section 4.5. We also use the NextHeader value from the first
 				// fragment.
-				it = header.MakeIPv6PayloadIterator(header.IPv6ExtensionHeaderIdentifier(proto), pkt.Data)
+				data := pkt.Data()
+				dataVV := buffer.NewVectorisedView(data.Size(), data.Views())
+				it = header.MakeIPv6PayloadIterator(header.IPv6ExtensionHeaderIdentifier(proto), dataVV)
 			}
 
 		case header.IPv6DestinationOptionsExtHdr:
@@ -1314,7 +1317,7 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
 			// For reassembled fragments, pkt.TransportHeader is unset, so this is a
 			// no-op and pkt.Data begins with the transport header.
 			extHdr.Buf.TrimFront(pkt.TransportHeader().View().Size())
-			pkt.Data = extHdr.Buf
+			pkt.Data().Replace(extHdr.Buf)
 
 			stats.PacketsDelivered.Increment()
 			if p := tcpip.TransportProtocolNumber(extHdr.Identifier); p == header.ICMPv6ProtocolNumber {
diff --git a/pkg/tcpip/network/ipv6/mld.go b/pkg/tcpip/network/ipv6/mld.go
index 205e36cdd..dd153466d 100644
--- a/pkg/tcpip/network/ipv6/mld.go
+++ b/pkg/tcpip/network/ipv6/mld.go
@@ -236,7 +236,11 @@ func (mld *mldState) writePacket(destAddress, groupAddress tcpip.Address, mldTyp
 		localAddress = header.IPv6Any
 	}
 
-	icmp.SetChecksum(header.ICMPv6Checksum(icmp, localAddress, destAddress, buffer.VectorisedView{}))
+	icmp.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{
+		Header: icmp,
+		Src:    localAddress,
+		Dst:    destAddress,
+	}))
 
 	extensionHeaders := header.IPv6ExtHdrSerializer{
 		header.IPv6SerializableHopByHopExtHdr{
diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go
index 721269c58..c22f60709 100644
--- a/pkg/tcpip/network/ipv6/ndp.go
+++ b/pkg/tcpip/network/ipv6/ndp.go
@@ -1721,7 +1721,11 @@ func (ndp *ndpState) startSolicitingRouters() {
 			icmpData.SetType(header.ICMPv6RouterSolicit)
 			rs := header.NDPRouterSolicit(icmpData.MessageBody())
 			rs.Options().Serialize(optsSerializer)
-			icmpData.SetChecksum(header.ICMPv6Checksum(icmpData, localAddr, header.IPv6AllRoutersMulticastAddress, buffer.VectorisedView{}))
+			icmpData.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{
+				Header: icmpData,
+				Src:    localAddr,
+				Dst:    header.IPv6AllRoutersMulticastAddress,
+			}))
 
 			pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
 				ReserveHeaderBytes: int(ndp.ep.MaxHeaderLength()),
@@ -1812,7 +1816,11 @@ func (e *endpoint) sendNDPNS(srcAddr, dstAddr, targetAddr tcpip.Address, remoteL
 	ns := header.NDPNeighborSolicit(icmp.MessageBody())
 	ns.SetTargetAddress(targetAddr)
 	ns.Options().Serialize(opts)
-	icmp.SetChecksum(header.ICMPv6Checksum(icmp, srcAddr, dstAddr, buffer.VectorisedView{}))
+	icmp.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{
+		Header: icmp,
+		Src:    srcAddr,
+		Dst:    dstAddr,
+	}))
 
 	pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
 		ReserveHeaderBytes: int(e.MaxHeaderLength()),