Use PacketBuffers, rather than VectorisedViews, in netstack.

PacketBuffers are analogous to Linux's sk_buff. They hold all information about
a packet, headers, and payload. This is important for:

* iptables to access various headers of packets
* Preventing the clutter of passing different net and link headers along with
  VectorisedViews to packet handling functions.

This change only affects the incoming packet path, and a future change will
change the outgoing path.

Benchmark               Regular         PacketBufferPtr  PacketBufferConcrete
--------------------------------------------------------------------------------
BM_Recvmsg             400.715MB/s      373.676MB/s      396.276MB/s
BM_Sendmsg             361.832MB/s      333.003MB/s      335.571MB/s
BM_Recvfrom            453.336MB/s      393.321MB/s      381.650MB/s
BM_Sendto              378.052MB/s      372.134MB/s      341.342MB/s
BM_SendmsgTCP/0/1k     353.711MB/s      316.216MB/s      322.747MB/s
BM_SendmsgTCP/0/2k     600.681MB/s      588.776MB/s      565.050MB/s
BM_SendmsgTCP/0/4k     995.301MB/s      888.808MB/s      941.888MB/s
BM_SendmsgTCP/0/8k     1.517GB/s        1.274GB/s        1.345GB/s
BM_SendmsgTCP/0/16k    1.872GB/s        1.586GB/s        1.698GB/s
BM_SendmsgTCP/0/32k    1.017GB/s        1.020GB/s        1.133GB/s
BM_SendmsgTCP/0/64k    475.626MB/s      584.587MB/s      627.027MB/s
BM_SendmsgTCP/0/128k   416.371MB/s      503.434MB/s      409.850MB/s
BM_SendmsgTCP/0/256k   323.449MB/s      449.599MB/s      388.852MB/s
BM_SendmsgTCP/0/512k   243.992MB/s      267.676MB/s      314.474MB/s
BM_SendmsgTCP/0/1M     95.138MB/s       95.874MB/s       95.417MB/s
BM_SendmsgTCP/0/2M     96.261MB/s       94.977MB/s       96.005MB/s
BM_SendmsgTCP/0/4M     96.512MB/s       95.978MB/s       95.370MB/s
BM_SendmsgTCP/0/8M     95.603MB/s       95.541MB/s       94.935MB/s
BM_SendmsgTCP/0/16M    94.598MB/s       94.696MB/s       94.521MB/s
BM_SendmsgTCP/0/32M    94.006MB/s       94.671MB/s       94.768MB/s
BM_SendmsgTCP/0/64M    94.133MB/s       94.333MB/s       94.746MB/s
BM_SendmsgTCP/0/128M   93.615MB/s       93.497MB/s       93.573MB/s
BM_SendmsgTCP/0/256M   93.241MB/s       95.100MB/s       93.272MB/s
BM_SendmsgTCP/1/1k     303.644MB/s      316.074MB/s      308.430MB/s
BM_SendmsgTCP/1/2k     537.093MB/s      584.962MB/s      529.020MB/s
BM_SendmsgTCP/1/4k     882.362MB/s      939.087MB/s      892.285MB/s
BM_SendmsgTCP/1/8k     1.272GB/s        1.394GB/s        1.296GB/s
BM_SendmsgTCP/1/16k    1.802GB/s        2.019GB/s        1.830GB/s
BM_SendmsgTCP/1/32k    2.084GB/s        2.173GB/s        2.156GB/s
BM_SendmsgTCP/1/64k    2.515GB/s        2.463GB/s        2.473GB/s
BM_SendmsgTCP/1/128k   2.811GB/s        3.004GB/s        2.946GB/s
BM_SendmsgTCP/1/256k   3.008GB/s        3.159GB/s        3.171GB/s
BM_SendmsgTCP/1/512k   2.980GB/s        3.150GB/s        3.126GB/s
BM_SendmsgTCP/1/1M     2.165GB/s        2.233GB/s        2.163GB/s
BM_SendmsgTCP/1/2M     2.370GB/s        2.219GB/s        2.453GB/s
BM_SendmsgTCP/1/4M     2.005GB/s        2.091GB/s        2.214GB/s
BM_SendmsgTCP/1/8M     2.111GB/s        2.013GB/s        2.109GB/s
BM_SendmsgTCP/1/16M    1.902GB/s        1.868GB/s        1.897GB/s
BM_SendmsgTCP/1/32M    1.655GB/s        1.665GB/s        1.635GB/s
BM_SendmsgTCP/1/64M    1.575GB/s        1.547GB/s        1.575GB/s
BM_SendmsgTCP/1/128M   1.524GB/s        1.584GB/s        1.580GB/s
BM_SendmsgTCP/1/256M   1.579GB/s        1.607GB/s        1.593GB/s

PiperOrigin-RevId: 278940079

8 files changed, 153 insertions, 108 deletions

diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go
index 525a25218..cc789b5af 100644
--- a/pkg/tcpip/stack/ndp_test.go
+++ b/pkg/tcpip/stack/ndp_test.go
@@ -328,7 +328,9 @@ func TestDADFail(t *testing.T) {
 			// Receive a packet to simulate multiple nodes owning or
 			// attempting to own the same address.
 			hdr := test.makeBuf(addr1)
-			e.Inject(header.IPv6ProtocolNumber, hdr.View().ToVectorisedView())
+			e.InjectInbound(header.IPv6ProtocolNumber, tcpip.PacketBuffer{
+				Data: hdr.View().ToVectorisedView(),
+			})
 
 			stat := test.getStat(s.Stats().ICMP.V6PacketsReceived)
 			if got := stat.Value(); got != 1 {
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 12969c74e..28a28ae6e 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -723,10 +723,10 @@ func (n *NIC) leaveGroupLocked(addr tcpip.Address) *tcpip.Error {
 	return nil
 }
 
-func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, localLinkAddr, remotelinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint, vv buffer.VectorisedView) {
+func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, localLinkAddr, remotelinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint, pkt tcpip.PacketBuffer) {
 	r := makeRoute(protocol, dst, src, localLinkAddr, ref, false /* handleLocal */, false /* multicastLoop */)
 	r.RemoteLinkAddress = remotelinkAddr
-	ref.ep.HandlePacket(&r, vv)
+	ref.ep.HandlePacket(&r, pkt)
 	ref.decRef()
 }
 
@@ -736,9 +736,9 @@ func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address,
 // Note that the ownership of the slice backing vv is retained by the caller.
 // This rule applies only to the slice itself, not to the items of the slice;
 // the ownership of the items is not retained by the caller.
-func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView, linkHeader buffer.View) {
+func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt tcpip.PacketBuffer) {
 	n.stats.Rx.Packets.Increment()
-	n.stats.Rx.Bytes.IncrementBy(uint64(vv.Size()))
+	n.stats.Rx.Bytes.IncrementBy(uint64(pkt.Data.Size()))
 
 	netProto, ok := n.stack.networkProtocols[protocol]
 	if !ok {
@@ -763,22 +763,22 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.Link
 	}
 	n.mu.RUnlock()
 	for _, ep := range packetEPs {
-		ep.HandlePacket(n.id, local, protocol, vv.Clone(nil), linkHeader)
+		ep.HandlePacket(n.id, local, protocol, pkt.Clone())
 	}
 
 	if netProto.Number() == header.IPv4ProtocolNumber || netProto.Number() == header.IPv6ProtocolNumber {
 		n.stack.stats.IP.PacketsReceived.Increment()
 	}
 
-	if len(vv.First()) < netProto.MinimumPacketSize() {
+	if len(pkt.Data.First()) < netProto.MinimumPacketSize() {
 		n.stack.stats.MalformedRcvdPackets.Increment()
 		return
 	}
 
-	src, dst := netProto.ParseAddresses(vv.First())
+	src, dst := netProto.ParseAddresses(pkt.Data.First())
 
 	if ref := n.getRef(protocol, dst); ref != nil {
-		handlePacket(protocol, dst, src, linkEP.LinkAddress(), remote, ref, vv)
+		handlePacket(protocol, dst, src, linkEP.LinkAddress(), remote, ref, pkt)
 		return
 	}
 
@@ -806,20 +806,20 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.Link
 		if ok {
 			r.RemoteAddress = src
 			// TODO(b/123449044): Update the source NIC as well.
-			ref.ep.HandlePacket(&r, vv)
+			ref.ep.HandlePacket(&r, pkt)
 			ref.decRef()
 		} else {
 			// n doesn't have a destination endpoint.
 			// Send the packet out of n.
-			hdr := buffer.NewPrependableFromView(vv.First())
-			vv.RemoveFirst()
+			hdr := buffer.NewPrependableFromView(pkt.Data.First())
+			pkt.Data.RemoveFirst()
 
 			// TODO(b/128629022): use route.WritePacket.
-			if err := n.linkEP.WritePacket(&r, nil /* gso */, hdr, vv, protocol); err != nil {
+			if err := n.linkEP.WritePacket(&r, nil /* gso */, hdr, pkt.Data, protocol); err != nil {
 				r.Stats().IP.OutgoingPacketErrors.Increment()
 			} else {
 				n.stats.Tx.Packets.Increment()
-				n.stats.Tx.Bytes.IncrementBy(uint64(hdr.UsedLength() + vv.Size()))
+				n.stats.Tx.Bytes.IncrementBy(uint64(hdr.UsedLength() + pkt.Data.Size()))
 			}
 		}
 		return
@@ -833,7 +833,7 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.Link
 
 // DeliverTransportPacket delivers the packets to the appropriate transport
 // protocol endpoint.
-func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView) {
+func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt tcpip.PacketBuffer) {
 	state, ok := n.stack.transportProtocols[protocol]
 	if !ok {
 		n.stack.stats.UnknownProtocolRcvdPackets.Increment()
@@ -845,41 +845,41 @@ func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolN
 	// Raw socket packets are delivered based solely on the transport
 	// protocol number. We do not inspect the payload to ensure it's
 	// validly formed.
-	n.stack.demux.deliverRawPacket(r, protocol, netHeader, vv)
+	n.stack.demux.deliverRawPacket(r, protocol, pkt)
 
-	if len(vv.First()) < transProto.MinimumPacketSize() {
+	if len(pkt.Data.First()) < transProto.MinimumPacketSize() {
 		n.stack.stats.MalformedRcvdPackets.Increment()
 		return
 	}
 
-	srcPort, dstPort, err := transProto.ParsePorts(vv.First())
+	srcPort, dstPort, err := transProto.ParsePorts(pkt.Data.First())
 	if err != nil {
 		n.stack.stats.MalformedRcvdPackets.Increment()
 		return
 	}
 
 	id := TransportEndpointID{dstPort, r.LocalAddress, srcPort, r.RemoteAddress}
-	if n.stack.demux.deliverPacket(r, protocol, netHeader, vv, id) {
+	if n.stack.demux.deliverPacket(r, protocol, pkt, id) {
 		return
 	}
 
 	// Try to deliver to per-stack default handler.
 	if state.defaultHandler != nil {
-		if state.defaultHandler(r, id, netHeader, vv) {
+		if state.defaultHandler(r, id, pkt) {
 			return
 		}
 	}
 
 	// We could not find an appropriate destination for this packet, so
 	// deliver it to the global handler.
-	if !transProto.HandleUnknownDestinationPacket(r, id, netHeader, vv) {
+	if !transProto.HandleUnknownDestinationPacket(r, id, pkt) {
 		n.stack.stats.MalformedRcvdPackets.Increment()
 	}
 }
 
 // DeliverTransportControlPacket delivers control packets to the appropriate
 // transport protocol endpoint.
-func (n *NIC) DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, vv buffer.VectorisedView) {
+func (n *NIC) DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt tcpip.PacketBuffer) {
 	state, ok := n.stack.transportProtocols[trans]
 	if !ok {
 		return
@@ -890,17 +890,17 @@ func (n *NIC) DeliverTransportControlPacket(local, remote tcpip.Address, net tcp
 	// ICMPv4 only guarantees that 8 bytes of the transport protocol will
 	// be present in the payload. We know that the ports are within the
 	// first 8 bytes for all known transport protocols.
-	if len(vv.First()) < 8 {
+	if len(pkt.Data.First()) < 8 {
 		return
 	}
 
-	srcPort, dstPort, err := transProto.ParsePorts(vv.First())
+	srcPort, dstPort, err := transProto.ParsePorts(pkt.Data.First())
 	if err != nil {
 		return
 	}
 
 	id := TransportEndpointID{srcPort, local, dstPort, remote}
-	if n.stack.demux.deliverControlPacket(n, net, trans, typ, extra, vv, id) {
+	if n.stack.demux.deliverControlPacket(n, net, trans, typ, extra, pkt, id) {
 		return
 	}
 }
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go
index d7c124e81..5806d294c 100644
--- a/pkg/tcpip/stack/registration.go
+++ b/pkg/tcpip/stack/registration.go
@@ -64,16 +64,15 @@ type TransportEndpoint interface {
 	UniqueID() uint64
 
 	// HandlePacket is called by the stack when new packets arrive to
-	// this transport endpoint.
+	// this transport endpoint. It sets pkt.TransportHeader.
 	//
-	// HandlePacket takes ownership of vv.
-	HandlePacket(r *Route, id TransportEndpointID, vv buffer.VectorisedView)
+	// HandlePacket takes ownership of pkt.
+	HandlePacket(r *Route, id TransportEndpointID, pkt tcpip.PacketBuffer)
 
-	// HandleControlPacket is called by the stack when new control (e.g.,
+	// HandleControlPacket is called by the stack when new control (e.g.
 	// ICMP) packets arrive to this transport endpoint.
-	//
-	// HandleControlPacket takes ownership of vv.
-	HandleControlPacket(id TransportEndpointID, typ ControlType, extra uint32, vv buffer.VectorisedView)
+	// HandleControlPacket takes ownership of pkt.
+	HandleControlPacket(id TransportEndpointID, typ ControlType, extra uint32, pkt tcpip.PacketBuffer)
 
 	// Close puts the endpoint in a closed state and frees all resources
 	// associated with it. This cleanup may happen asynchronously. Wait can
@@ -99,8 +98,8 @@ type RawTransportEndpoint interface {
 	// this transport endpoint. The packet contains all data from the link
 	// layer up.
 	//
-	// HandlePacket takes ownership of packet and netHeader.
-	HandlePacket(r *Route, netHeader buffer.View, packet buffer.VectorisedView)
+	// HandlePacket takes ownership of pkt.
+	HandlePacket(r *Route, pkt tcpip.PacketBuffer)
 }
 
 // PacketEndpoint is the interface that needs to be implemented by packet
@@ -117,8 +116,8 @@ type PacketEndpoint interface {
 	// linkHeader may have a length of 0, in which case the PacketEndpoint
 	// should construct its own ethernet header for applications.
 	//
-	// HandlePacket takes ownership of packet and linkHeader.
-	HandlePacket(nicid tcpip.NICID, addr tcpip.LinkAddress, netProto tcpip.NetworkProtocolNumber, packet buffer.VectorisedView, linkHeader buffer.View)
+	// HandlePacket takes ownership of pkt.
+	HandlePacket(nicid tcpip.NICID, addr tcpip.LinkAddress, netProto tcpip.NetworkProtocolNumber, pkt tcpip.PacketBuffer)
 }
 
 // TransportProtocol is the interface that needs to be implemented by transport
@@ -148,7 +147,9 @@ type TransportProtocol interface {
 	//
 	// The return value indicates whether the packet was well-formed (for
 	// stats purposes only).
-	HandleUnknownDestinationPacket(r *Route, id TransportEndpointID, netHeader buffer.View, vv buffer.VectorisedView) bool
+	//
+	// HandleUnknownDestinationPacket takes ownership of pkt.
+	HandleUnknownDestinationPacket(r *Route, id TransportEndpointID, pkt tcpip.PacketBuffer) bool
 
 	// SetOption allows enabling/disabling protocol specific features.
 	// SetOption returns an error if the option is not supported or the
@@ -166,17 +167,21 @@ type TransportProtocol interface {
 // the network layer.
 type TransportDispatcher interface {
 	// DeliverTransportPacket delivers packets to the appropriate
-	// transport protocol endpoint. It also returns the network layer
-	// header for the enpoint to inspect or pass up the stack.
+	// transport protocol endpoint.
+	//
+	// pkt.NetworkHeader must be set before calling DeliverTransportPacket.
 	//
-	// DeliverTransportPacket takes ownership of vv and netHeader.
-	DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView)
+	// DeliverTransportPacket takes ownership of pkt.
+	DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt tcpip.PacketBuffer)
 
 	// DeliverTransportControlPacket delivers control packets to the
 	// appropriate transport protocol endpoint.
 	//
-	// DeliverTransportControlPacket takes ownership of vv.
-	DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, vv buffer.VectorisedView)
+	// pkt.NetworkHeader must be set before calling
+	// DeliverTransportControlPacket.
+	//
+	// DeliverTransportControlPacket takes ownership of pkt.
+	DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt tcpip.PacketBuffer)
 }
 
 // PacketLooping specifies where an outbound packet should be sent.
@@ -248,10 +253,10 @@ type NetworkEndpoint interface {
 	NICID() tcpip.NICID
 
 	// HandlePacket is called by the link layer when new packets arrive to
-	// this network endpoint.
+	// this network endpoint. It sets pkt.NetworkHeader.
 	//
-	// HandlePacket takes ownership of vv.
-	HandlePacket(r *Route, vv buffer.VectorisedView)
+	// HandlePacket takes ownership of pkt.
+	HandlePacket(r *Route, pkt tcpip.PacketBuffer)
 
 	// Close is called when the endpoint is reomved from a stack.
 	Close()
@@ -294,11 +299,14 @@ type NetworkProtocol interface {
 // the data link layer.
 type NetworkDispatcher interface {
 	// DeliverNetworkPacket finds the appropriate network protocol endpoint
-	// and hands the packet over for further processing. linkHeader may have
-	// length 0 when the caller does not have ethernet data.
+	// and hands the packet over for further processing.
+	//
+	// pkt.LinkHeader may or may not be set before calling
+	// DeliverNetworkPacket. Some packets do not have link headers (e.g.
+	// packets sent via loopback), and won't have the field set.
 	//
-	// DeliverNetworkPacket takes ownership of vv and linkHeader.
-	DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView, linkHeader buffer.View)
+	// DeliverNetworkPacket takes ownership of pkt.
+	DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt tcpip.PacketBuffer)
 }
 
 // LinkEndpointCapabilities is the type associated with the capabilities
@@ -329,7 +337,9 @@ const (
 
 // LinkEndpoint is the interface implemented by data link layer protocols (e.g.,
 // ethernet, loopback, raw) and used by network layer protocols to send packets
-// out through the implementer's data link endpoint.
+// out through the implementer's data link endpoint. When a link header exists,
+// it sets each tcpip.PacketBuffer's LinkHeader field before passing it up the
+// stack.
 type LinkEndpoint interface {
 	// MTU is the maximum transmission unit for this endpoint. This is
 	// usually dictated by the backing physical network; when such a
@@ -395,7 +405,7 @@ type InjectableLinkEndpoint interface {
 	LinkEndpoint
 
 	// InjectInbound injects an inbound packet.
-	InjectInbound(protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView)
+	InjectInbound(protocol tcpip.NetworkProtocolNumber, pkt tcpip.PacketBuffer)
 
 	// InjectOutbound writes a fully formed outbound packet directly to the
 	// link.
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 8b141cafd..08599d765 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -51,7 +51,7 @@ const (
 
 type transportProtocolState struct {
 	proto          TransportProtocol
-	defaultHandler func(r *Route, id TransportEndpointID, netHeader buffer.View, vv buffer.VectorisedView) bool
+	defaultHandler func(r *Route, id TransportEndpointID, pkt tcpip.PacketBuffer) bool
 }
 
 // TCPProbeFunc is the expected function type for a TCP probe function to be
@@ -641,7 +641,7 @@ func (s *Stack) TransportProtocolOption(transport tcpip.TransportProtocolNumber,
 //
 // It must be called only during initialization of the stack. Changing it as the
 // stack is operating is not supported.
-func (s *Stack) SetTransportProtocolHandler(p tcpip.TransportProtocolNumber, h func(*Route, TransportEndpointID, buffer.View, buffer.VectorisedView) bool) {
+func (s *Stack) SetTransportProtocolHandler(p tcpip.TransportProtocolNumber, h func(*Route, TransportEndpointID, tcpip.PacketBuffer) bool) {
 	state := s.transportProtocols[p]
 	if state != nil {
 		state.defaultHandler = h
diff --git a/pkg/tcpip/stack/stack_test.go b/pkg/tcpip/stack/stack_test.go
index 9dae853d0..1fac5477f 100644
--- a/pkg/tcpip/stack/stack_test.go
+++ b/pkg/tcpip/stack/stack_test.go
@@ -86,28 +86,28 @@ func (f *fakeNetworkEndpoint) ID() *stack.NetworkEndpointID {
 	return &f.id
 }
 
-func (f *fakeNetworkEndpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) {
+func (f *fakeNetworkEndpoint) HandlePacket(r *stack.Route, pkt tcpip.PacketBuffer) {
 	// Increment the received packet count in the protocol descriptor.
 	f.proto.packetCount[int(f.id.LocalAddress[0])%len(f.proto.packetCount)]++
 
 	// Consume the network header.
-	b := vv.First()
-	vv.TrimFront(fakeNetHeaderLen)
+	b := pkt.Data.First()
+	pkt.Data.TrimFront(fakeNetHeaderLen)
 
 	// Handle control packets.
 	if b[2] == uint8(fakeControlProtocol) {
-		nb := vv.First()
+		nb := pkt.Data.First()
 		if len(nb) < fakeNetHeaderLen {
 			return
 		}
 
-		vv.TrimFront(fakeNetHeaderLen)
-		f.dispatcher.DeliverTransportControlPacket(tcpip.Address(nb[1:2]), tcpip.Address(nb[0:1]), fakeNetNumber, tcpip.TransportProtocolNumber(nb[2]), stack.ControlPortUnreachable, 0, vv)
+		pkt.Data.TrimFront(fakeNetHeaderLen)
+		f.dispatcher.DeliverTransportControlPacket(tcpip.Address(nb[1:2]), tcpip.Address(nb[0:1]), fakeNetNumber, tcpip.TransportProtocolNumber(nb[2]), stack.ControlPortUnreachable, 0, pkt)
 		return
 	}
 
 	// Dispatch the packet to the transport protocol.
-	f.dispatcher.DeliverTransportPacket(r, tcpip.TransportProtocolNumber(b[2]), buffer.View([]byte{}), vv)
+	f.dispatcher.DeliverTransportPacket(r, tcpip.TransportProtocolNumber(b[2]), pkt)
 }
 
 func (f *fakeNetworkEndpoint) MaxHeaderLength() uint16 {
@@ -138,7 +138,9 @@ func (f *fakeNetworkEndpoint) WritePacket(r *stack.Route, gso *stack.GSO, hdr bu
 		views[0] = hdr.View()
 		views = append(views, payload.Views()...)
 		vv := buffer.NewVectorisedView(len(views[0])+payload.Size(), views)
-		f.HandlePacket(r, vv)
+		f.HandlePacket(r, tcpip.PacketBuffer{
+			Data: vv,
+		})
 	}
 	if loop&stack.PacketOut == 0 {
 		return nil
@@ -259,7 +261,9 @@ func TestNetworkReceive(t *testing.T) {
 
 	// Make sure packet with wrong address is not delivered.
 	buf[0] = 3
-	ep.Inject(fakeNetNumber, buf.ToVectorisedView())
+	ep.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeNet.packetCount[1] != 0 {
 		t.Errorf("packetCount[1] = %d, want %d", fakeNet.packetCount[1], 0)
 	}
@@ -269,7 +273,9 @@ func TestNetworkReceive(t *testing.T) {
 
 	// Make sure packet is delivered to first endpoint.
 	buf[0] = 1
-	ep.Inject(fakeNetNumber, buf.ToVectorisedView())
+	ep.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeNet.packetCount[1] != 1 {
 		t.Errorf("packetCount[1] = %d, want %d", fakeNet.packetCount[1], 1)
 	}
@@ -279,7 +285,9 @@ func TestNetworkReceive(t *testing.T) {
 
 	// Make sure packet is delivered to second endpoint.
 	buf[0] = 2
-	ep.Inject(fakeNetNumber, buf.ToVectorisedView())
+	ep.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeNet.packetCount[1] != 1 {
 		t.Errorf("packetCount[1] = %d, want %d", fakeNet.packetCount[1], 1)
 	}
@@ -288,7 +296,9 @@ func TestNetworkReceive(t *testing.T) {
 	}
 
 	// Make sure packet is not delivered if protocol number is wrong.
-	ep.Inject(fakeNetNumber-1, buf.ToVectorisedView())
+	ep.InjectInbound(fakeNetNumber-1, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeNet.packetCount[1] != 1 {
 		t.Errorf("packetCount[1] = %d, want %d", fakeNet.packetCount[1], 1)
 	}
@@ -298,7 +308,9 @@ func TestNetworkReceive(t *testing.T) {
 
 	// Make sure packet that is too small is dropped.
 	buf.CapLength(2)
-	ep.Inject(fakeNetNumber, buf.ToVectorisedView())
+	ep.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeNet.packetCount[1] != 1 {
 		t.Errorf("packetCount[1] = %d, want %d", fakeNet.packetCount[1], 1)
 	}
@@ -373,7 +385,9 @@ func testFailingRecv(t *testing.T, fakeNet *fakeNetworkProtocol, localAddrByte b
 
 func testRecvInternal(t *testing.T, fakeNet *fakeNetworkProtocol, localAddrByte byte, ep *channel.Endpoint, buf buffer.View, want int) {
 	t.Helper()
-	ep.Inject(fakeNetNumber, buf.ToVectorisedView())
+	ep.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if got := fakeNet.PacketCount(localAddrByte); got != want {
 		t.Errorf("receive packet count: got = %d, want %d", got, want)
 	}
@@ -1795,7 +1809,9 @@ func TestNICStats(t *testing.T) {
 
 	// Send a packet to address 1.
 	buf := buffer.NewView(30)
-	ep1.Inject(fakeNetNumber, buf.ToVectorisedView())
+	ep1.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if got, want := s.NICInfo()[1].Stats.Rx.Packets.Value(), uint64(1); got != want {
 		t.Errorf("got Rx.Packets.Value() = %d, want = %d", got, want)
 	}
@@ -1855,7 +1871,9 @@ func TestNICForwarding(t *testing.T) {
 	// Send a packet to address 3.
 	buf := buffer.NewView(30)
 	buf[0] = 3
-	ep1.Inject(fakeNetNumber, buf.ToVectorisedView())
+	ep1.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 
 	select {
 	case <-ep2.C:
diff --git a/pkg/tcpip/stack/transport_demuxer.go b/pkg/tcpip/stack/transport_demuxer.go
index ccd3d030e..594570216 100644
--- a/pkg/tcpip/stack/transport_demuxer.go
+++ b/pkg/tcpip/stack/transport_demuxer.go
@@ -21,7 +21,6 @@ import (
 	"sync"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/hash/jenkins"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
 )
@@ -86,7 +85,7 @@ func (epsByNic *endpointsByNic) transportEndpoints() []TransportEndpoint {
 
 // HandlePacket is called by the stack when new packets arrive to this transport
 // endpoint.
-func (epsByNic *endpointsByNic) handlePacket(r *Route, id TransportEndpointID, vv buffer.VectorisedView) {
+func (epsByNic *endpointsByNic) handlePacket(r *Route, id TransportEndpointID, pkt tcpip.PacketBuffer) {
 	epsByNic.mu.RLock()
 
 	mpep, ok := epsByNic.endpoints[r.ref.nic.ID()]
@@ -100,18 +99,18 @@ func (epsByNic *endpointsByNic) handlePacket(r *Route, id TransportEndpointID, v
 	// If this is a broadcast or multicast datagram, deliver the datagram to all
 	// endpoints bound to the right device.
 	if isMulticastOrBroadcast(id.LocalAddress) {
-		mpep.handlePacketAll(r, id, vv)
+		mpep.handlePacketAll(r, id, pkt)
 		epsByNic.mu.RUnlock() // Don't use defer for performance reasons.
 		return
 	}
 
 	// multiPortEndpoints are guaranteed to have at least one element.
-	selectEndpoint(id, mpep, epsByNic.seed).HandlePacket(r, id, vv)
+	selectEndpoint(id, mpep, epsByNic.seed).HandlePacket(r, id, pkt)
 	epsByNic.mu.RUnlock() // Don't use defer for performance reasons.
 }
 
 // HandleControlPacket implements stack.TransportEndpoint.HandleControlPacket.
-func (epsByNic *endpointsByNic) handleControlPacket(n *NIC, id TransportEndpointID, typ ControlType, extra uint32, vv buffer.VectorisedView) {
+func (epsByNic *endpointsByNic) handleControlPacket(n *NIC, id TransportEndpointID, typ ControlType, extra uint32, pkt tcpip.PacketBuffer) {
 	epsByNic.mu.RLock()
 	defer epsByNic.mu.RUnlock()
 
@@ -127,7 +126,7 @@ func (epsByNic *endpointsByNic) handleControlPacket(n *NIC, id TransportEndpoint
 	// broadcast like we are doing with handlePacket above?
 
 	// multiPortEndpoints are guaranteed to have at least one element.
-	selectEndpoint(id, mpep, epsByNic.seed).HandleControlPacket(id, typ, extra, vv)
+	selectEndpoint(id, mpep, epsByNic.seed).HandleControlPacket(id, typ, extra, pkt)
 }
 
 // registerEndpoint returns true if it succeeds. It fails and returns
@@ -258,18 +257,16 @@ func selectEndpoint(id TransportEndpointID, mpep *multiPortEndpoint, seed uint32
 	return mpep.endpointsArr[idx]
 }
 
-func (ep *multiPortEndpoint) handlePacketAll(r *Route, id TransportEndpointID, vv buffer.VectorisedView) {
+func (ep *multiPortEndpoint) handlePacketAll(r *Route, id TransportEndpointID, pkt tcpip.PacketBuffer) {
 	ep.mu.RLock()
 	for i, endpoint := range ep.endpointsArr {
-		// HandlePacket modifies vv, so each endpoint needs its own copy except for
-		// the final one.
+		// HandlePacket takes ownership of pkt, so each endpoint needs
+		// its own copy except for the final one.
 		if i == len(ep.endpointsArr)-1 {
-			endpoint.HandlePacket(r, id, vv)
+			endpoint.HandlePacket(r, id, pkt)
 			break
 		}
-		vvCopy := buffer.NewView(vv.Size())
-		copy(vvCopy, vv.ToView())
-		endpoint.HandlePacket(r, id, vvCopy.ToVectorisedView())
+		endpoint.HandlePacket(r, id, pkt.Clone())
 	}
 	ep.mu.RUnlock() // Don't use defer for performance reasons.
 }
@@ -395,7 +392,7 @@ var loopbackSubnet = func() tcpip.Subnet {
 // deliverPacket attempts to find one or more matching transport endpoints, and
 // then, if matches are found, delivers the packet to them. Returns true if it
 // found one or more endpoints, false otherwise.
-func (d *transportDemuxer) deliverPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView, id TransportEndpointID) bool {
+func (d *transportDemuxer) deliverPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt tcpip.PacketBuffer, id TransportEndpointID) bool {
 	eps, ok := d.protocol[protocolIDs{r.NetProto, protocol}]
 	if !ok {
 		return false
@@ -408,8 +405,8 @@ func (d *transportDemuxer) deliverPacket(r *Route, protocol tcpip.TransportProto
 	// transport endpoints.
 	var destEps []*endpointsByNic
 	if protocol == header.UDPProtocolNumber && isMulticastOrBroadcast(id.LocalAddress) {
-		destEps = d.findAllEndpointsLocked(eps, vv, id)
-	} else if ep := d.findEndpointLocked(eps, vv, id); ep != nil {
+		destEps = d.findAllEndpointsLocked(eps, id)
+	} else if ep := d.findEndpointLocked(eps, id); ep != nil {
 		destEps = append(destEps, ep)
 	}
 
@@ -424,17 +421,19 @@ func (d *transportDemuxer) deliverPacket(r *Route, protocol tcpip.TransportProto
 		return false
 	}
 
-	// Deliver the packet.
-	for _, ep := range destEps {
-		ep.handlePacket(r, id, vv)
+	// HandlePacket takes ownership of pkt, so each endpoint needs its own
+	// copy except for the final one.
+	for _, ep := range destEps[:len(destEps)-1] {
+		ep.handlePacket(r, id, pkt.Clone())
 	}
+	destEps[len(destEps)-1].handlePacket(r, id, pkt)
 
 	return true
 }
 
 // deliverRawPacket attempts to deliver the given packet and returns whether it
 // was delivered successfully.
-func (d *transportDemuxer) deliverRawPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView) bool {
+func (d *transportDemuxer) deliverRawPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt tcpip.PacketBuffer) bool {
 	eps, ok := d.protocol[protocolIDs{r.NetProto, protocol}]
 	if !ok {
 		return false
@@ -448,7 +447,7 @@ func (d *transportDemuxer) deliverRawPacket(r *Route, protocol tcpip.TransportPr
 	for _, rawEP := range eps.rawEndpoints {
 		// Each endpoint gets its own copy of the packet for the sake
 		// of save/restore.
-		rawEP.HandlePacket(r, buffer.NewViewFromBytes(netHeader), vv.ToView().ToVectorisedView())
+		rawEP.HandlePacket(r, pkt)
 		foundRaw = true
 	}
 	eps.mu.RUnlock()
@@ -458,7 +457,7 @@ func (d *transportDemuxer) deliverRawPacket(r *Route, protocol tcpip.TransportPr
 
 // deliverControlPacket attempts to deliver the given control packet. Returns
 // true if it found an endpoint, false otherwise.
-func (d *transportDemuxer) deliverControlPacket(n *NIC, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, vv buffer.VectorisedView, id TransportEndpointID) bool {
+func (d *transportDemuxer) deliverControlPacket(n *NIC, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt tcpip.PacketBuffer, id TransportEndpointID) bool {
 	eps, ok := d.protocol[protocolIDs{net, trans}]
 	if !ok {
 		return false
@@ -466,7 +465,7 @@ func (d *transportDemuxer) deliverControlPacket(n *NIC, net tcpip.NetworkProtoco
 
 	// Try to find the endpoint.
 	eps.mu.RLock()
-	ep := d.findEndpointLocked(eps, vv, id)
+	ep := d.findEndpointLocked(eps, id)
 	eps.mu.RUnlock()
 
 	// Fail if we didn't find one.
@@ -475,12 +474,12 @@ func (d *transportDemuxer) deliverControlPacket(n *NIC, net tcpip.NetworkProtoco
 	}
 
 	// Deliver the packet.
-	ep.handleControlPacket(n, id, typ, extra, vv)
+	ep.handleControlPacket(n, id, typ, extra, pkt)
 
 	return true
 }
 
-func (d *transportDemuxer) findAllEndpointsLocked(eps *transportEndpoints, vv buffer.VectorisedView, id TransportEndpointID) []*endpointsByNic {
+func (d *transportDemuxer) findAllEndpointsLocked(eps *transportEndpoints, id TransportEndpointID) []*endpointsByNic {
 	var matchedEPs []*endpointsByNic
 	// Try to find a match with the id as provided.
 	if ep, ok := eps.endpoints[id]; ok {
@@ -514,8 +513,8 @@ func (d *transportDemuxer) findAllEndpointsLocked(eps *transportEndpoints, vv bu
 
 // findEndpointLocked returns the endpoint that most closely matches the given
 // id.
-func (d *transportDemuxer) findEndpointLocked(eps *transportEndpoints, vv buffer.VectorisedView, id TransportEndpointID) *endpointsByNic {
-	if matchedEPs := d.findAllEndpointsLocked(eps, vv, id); len(matchedEPs) > 0 {
+func (d *transportDemuxer) findEndpointLocked(eps *transportEndpoints, id TransportEndpointID) *endpointsByNic {
+	if matchedEPs := d.findAllEndpointsLocked(eps, id); len(matchedEPs) > 0 {
 		return matchedEPs[0]
 	}
 	return nil
diff --git a/pkg/tcpip/stack/transport_demuxer_test.go b/pkg/tcpip/stack/transport_demuxer_test.go
index 210233dc0..f54117c4e 100644
--- a/pkg/tcpip/stack/transport_demuxer_test.go
+++ b/pkg/tcpip/stack/transport_demuxer_test.go
@@ -156,7 +156,9 @@ func (c *testContext) sendV6Packet(payload []byte, h *headers, linkEpName string
 	u.SetChecksum(^u.CalculateChecksum(xsum))
 
 	// Inject packet.
-	c.linkEPs[linkEpName].Inject(ipv6.ProtocolNumber, buf.ToVectorisedView())
+	c.linkEPs[linkEpName].InjectInbound(ipv6.ProtocolNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 }
 
 func TestTransportDemuxerRegister(t *testing.T) {
diff --git a/pkg/tcpip/stack/transport_test.go b/pkg/tcpip/stack/transport_test.go
index 203e79f56..2cacea99a 100644
--- a/pkg/tcpip/stack/transport_test.go
+++ b/pkg/tcpip/stack/transport_test.go
@@ -197,7 +197,7 @@ func (*fakeTransportEndpoint) GetRemoteAddress() (tcpip.FullAddress, *tcpip.Erro
 	return tcpip.FullAddress{}, nil
 }
 
-func (f *fakeTransportEndpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, _ buffer.VectorisedView) {
+func (f *fakeTransportEndpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, _ tcpip.PacketBuffer) {
 	// Increment the number of received packets.
 	f.proto.packetCount++
 	if f.acceptQueue != nil {
@@ -214,7 +214,7 @@ func (f *fakeTransportEndpoint) HandlePacket(r *stack.Route, id stack.TransportE
 	}
 }
 
-func (f *fakeTransportEndpoint) HandleControlPacket(stack.TransportEndpointID, stack.ControlType, uint32, buffer.VectorisedView) {
+func (f *fakeTransportEndpoint) HandleControlPacket(stack.TransportEndpointID, stack.ControlType, uint32, tcpip.PacketBuffer) {
 	// Increment the number of received control packets.
 	f.proto.controlCount++
 }
@@ -271,7 +271,7 @@ func (*fakeTransportProtocol) ParsePorts(buffer.View) (src, dst uint16, err *tcp
 	return 0, 0, nil
 }
 
-func (*fakeTransportProtocol) HandleUnknownDestinationPacket(*stack.Route, stack.TransportEndpointID, buffer.View, buffer.VectorisedView) bool {
+func (*fakeTransportProtocol) HandleUnknownDestinationPacket(*stack.Route, stack.TransportEndpointID, tcpip.PacketBuffer) bool {
 	return true
 }
 
@@ -342,7 +342,9 @@ func TestTransportReceive(t *testing.T) {
 	// Make sure packet with wrong protocol is not delivered.
 	buf[0] = 1
 	buf[2] = 0
-	linkEP.Inject(fakeNetNumber, buf.ToVectorisedView())
+	linkEP.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeTrans.packetCount != 0 {
 		t.Errorf("packetCount = %d, want %d", fakeTrans.packetCount, 0)
 	}
@@ -351,7 +353,9 @@ func TestTransportReceive(t *testing.T) {
 	buf[0] = 1
 	buf[1] = 3
 	buf[2] = byte(fakeTransNumber)
-	linkEP.Inject(fakeNetNumber, buf.ToVectorisedView())
+	linkEP.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeTrans.packetCount != 0 {
 		t.Errorf("packetCount = %d, want %d", fakeTrans.packetCount, 0)
 	}
@@ -360,7 +364,9 @@ func TestTransportReceive(t *testing.T) {
 	buf[0] = 1
 	buf[1] = 2
 	buf[2] = byte(fakeTransNumber)
-	linkEP.Inject(fakeNetNumber, buf.ToVectorisedView())
+	linkEP.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeTrans.packetCount != 1 {
 		t.Errorf("packetCount = %d, want %d", fakeTrans.packetCount, 1)
 	}
@@ -413,7 +419,9 @@ func TestTransportControlReceive(t *testing.T) {
 	buf[fakeNetHeaderLen+0] = 0
 	buf[fakeNetHeaderLen+1] = 1
 	buf[fakeNetHeaderLen+2] = 0
-	linkEP.Inject(fakeNetNumber, buf.ToVectorisedView())
+	linkEP.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeTrans.controlCount != 0 {
 		t.Errorf("controlCount = %d, want %d", fakeTrans.controlCount, 0)
 	}
@@ -422,7 +430,9 @@ func TestTransportControlReceive(t *testing.T) {
 	buf[fakeNetHeaderLen+0] = 3
 	buf[fakeNetHeaderLen+1] = 1
 	buf[fakeNetHeaderLen+2] = byte(fakeTransNumber)
-	linkEP.Inject(fakeNetNumber, buf.ToVectorisedView())
+	linkEP.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeTrans.controlCount != 0 {
 		t.Errorf("controlCount = %d, want %d", fakeTrans.controlCount, 0)
 	}
@@ -431,7 +441,9 @@ func TestTransportControlReceive(t *testing.T) {
 	buf[fakeNetHeaderLen+0] = 2
 	buf[fakeNetHeaderLen+1] = 1
 	buf[fakeNetHeaderLen+2] = byte(fakeTransNumber)
-	linkEP.Inject(fakeNetNumber, buf.ToVectorisedView())
+	linkEP.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: buf.ToVectorisedView(),
+	})
 	if fakeTrans.controlCount != 1 {
 		t.Errorf("controlCount = %d, want %d", fakeTrans.controlCount, 1)
 	}
@@ -584,7 +596,9 @@ func TestTransportForwarding(t *testing.T) {
 	req[0] = 1
 	req[1] = 3
 	req[2] = byte(fakeTransNumber)
-	ep2.Inject(fakeNetNumber, req.ToVectorisedView())
+	ep2.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{
+		Data: req.ToVectorisedView(),
+	})
 
 	aep, _, err := ep.Accept()
 	if err != nil || aep == nil {