Merge release-20200522.0-72-gd3a8bffe (automated)

11 files changed, 68 insertions, 41 deletions

diff --git a/pkg/tcpip/stack/conntrack.go b/pkg/tcpip/stack/conntrack.go
index 7d1ede1f2..d4053be08 100644
--- a/pkg/tcpip/stack/conntrack.go
+++ b/pkg/tcpip/stack/conntrack.go
@@ -186,7 +186,7 @@ func parseHeaders(pkt *PacketBuffer) {
 }
 
 // packetToTuple converts packet to a tuple in original direction.
-func packetToTuple(pkt PacketBuffer, hook Hook) (connTrackTuple, *tcpip.Error) {
+func packetToTuple(pkt *PacketBuffer, hook Hook) (connTrackTuple, *tcpip.Error) {
 	var tuple connTrackTuple
 
 	netHeader := header.IPv4(pkt.NetworkHeader)
@@ -265,7 +265,7 @@ func (ct *ConnTrackTable) connTrackForPacket(pkt *PacketBuffer, hook Hook, creat
 	}
 
 	var dir ctDirection
-	tuple, err := packetToTuple(*pkt, hook)
+	tuple, err := packetToTuple(pkt, hook)
 	if err != nil {
 		return nil, dir
 	}
diff --git a/pkg/tcpip/stack/forwarder.go b/pkg/tcpip/stack/forwarder.go
index 6b64cd37f..3eff141e6 100644
--- a/pkg/tcpip/stack/forwarder.go
+++ b/pkg/tcpip/stack/forwarder.go
@@ -32,7 +32,7 @@ type pendingPacket struct {
 	nic   *NIC
 	route *Route
 	proto tcpip.NetworkProtocolNumber
-	pkt   PacketBuffer
+	pkt   *PacketBuffer
 }
 
 type forwardQueue struct {
@@ -50,7 +50,7 @@ func newForwardQueue() *forwardQueue {
 	return &forwardQueue{packets: make(map[<-chan struct{}][]*pendingPacket)}
 }
 
-func (f *forwardQueue) enqueue(ch <-chan struct{}, n *NIC, r *Route, protocol tcpip.NetworkProtocolNumber, pkt PacketBuffer) {
+func (f *forwardQueue) enqueue(ch <-chan struct{}, n *NIC, r *Route, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
 	shouldWait := false
 
 	f.Lock()
diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go
index 709ede3fa..d989dbe91 100644
--- a/pkg/tcpip/stack/iptables.go
+++ b/pkg/tcpip/stack/iptables.go
@@ -321,7 +321,7 @@ func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx
 	// Go through each rule matcher. If they all match, run
 	// the rule target.
 	for _, matcher := range rule.Matchers {
-		matches, hotdrop := matcher.Match(hook, *pkt, "")
+		matches, hotdrop := matcher.Match(hook, pkt, "")
 		if hotdrop {
 			return RuleDrop, 0
 		}
diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go
index a3bd3e700..af72b9c46 100644
--- a/pkg/tcpip/stack/iptables_types.go
+++ b/pkg/tcpip/stack/iptables_types.go
@@ -245,7 +245,7 @@ type Matcher interface {
 	// used for suspicious packets.
 	//
 	// Precondition: packet.NetworkHeader is set.
-	Match(hook Hook, packet PacketBuffer, interfaceName string) (matches bool, hotdrop bool)
+	Match(hook Hook, packet *PacketBuffer, interfaceName string) (matches bool, hotdrop bool)
 }
 
 // A Target is the interface for taking an action for a packet.
diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go
index 526c7d6ff..ae7a8f740 100644
--- a/pkg/tcpip/stack/ndp.go
+++ b/pkg/tcpip/stack/ndp.go
@@ -750,7 +750,7 @@ func (ndp *ndpState) sendDADPacket(addr tcpip.Address) *tcpip.Error {
 			Protocol: header.ICMPv6ProtocolNumber,
 			TTL:      header.NDPHopLimit,
 			TOS:      DefaultTOS,
-		}, PacketBuffer{Header: hdr},
+		}, &PacketBuffer{Header: hdr},
 	); err != nil {
 		sent.Dropped.Increment()
 		return err
@@ -1881,7 +1881,7 @@ func (ndp *ndpState) startSolicitingRouters() {
 				Protocol: header.ICMPv6ProtocolNumber,
 				TTL:      header.NDPHopLimit,
 				TOS:      DefaultTOS,
-			}, PacketBuffer{Header: hdr},
+			}, &PacketBuffer{Header: hdr},
 		); err != nil {
 			sent.Dropped.Increment()
 			log.Printf("startSolicitingRouters: error writing NDP router solicit message on NIC(%d); err = %s", ndp.nic.ID(), err)
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 05646e5e2..ec8e3cb85 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -1153,7 +1153,7 @@ func (n *NIC) isInGroup(addr tcpip.Address) bool {
 	return joins != 0
 }
 
-func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, localLinkAddr, remotelinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint, pkt PacketBuffer) {
+func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, localLinkAddr, remotelinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint, pkt *PacketBuffer) {
 	r := makeRoute(protocol, dst, src, localLinkAddr, ref, false /* handleLocal */, false /* multicastLoop */)
 	r.RemoteLinkAddress = remotelinkAddr
 
@@ -1167,7 +1167,7 @@ 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(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt PacketBuffer) {
+func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
 	n.mu.RLock()
 	enabled := n.mu.enabled
 	// If the NIC is not yet enabled, don't receive any packets.
@@ -1233,7 +1233,7 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp
 		// iptables filtering.
 		ipt := n.stack.IPTables()
 		address := n.primaryAddress(protocol)
-		if ok := ipt.Check(Prerouting, &pkt, nil, nil, address.Address, ""); !ok {
+		if ok := ipt.Check(Prerouting, pkt, nil, nil, address.Address, ""); !ok {
 			// iptables is telling us to drop the packet.
 			return
 		}
@@ -1298,7 +1298,7 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp
 	}
 }
 
-func (n *NIC) forwardPacket(r *Route, protocol tcpip.NetworkProtocolNumber, pkt PacketBuffer) {
+func (n *NIC) forwardPacket(r *Route, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
 	// TODO(b/143425874) Decrease the TTL field in forwarded packets.
 	if linkHeaderLen := int(n.linkEP.MaxHeaderLength()); linkHeaderLen != 0 {
 		pkt.Header = buffer.NewPrependable(linkHeaderLen)
@@ -1318,7 +1318,7 @@ func (n *NIC) forwardPacket(r *Route, protocol tcpip.NetworkProtocolNumber, pkt
 
 // DeliverTransportPacket delivers the packets to the appropriate transport
 // protocol endpoint.
-func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt PacketBuffer) {
+func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) {
 	state, ok := n.stack.transportProtocols[protocol]
 	if !ok {
 		n.stack.stats.UnknownProtocolRcvdPackets.Increment()
@@ -1365,7 +1365,7 @@ func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolN
 
 // 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, pkt PacketBuffer) {
+func (n *NIC) DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt *PacketBuffer) {
 	state, ok := n.stack.transportProtocols[trans]
 	if !ok {
 		return
diff --git a/pkg/tcpip/stack/packet_buffer.go b/pkg/tcpip/stack/packet_buffer.go
index 926df4d7b..1b5da6017 100644
--- a/pkg/tcpip/stack/packet_buffer.go
+++ b/pkg/tcpip/stack/packet_buffer.go
@@ -24,6 +24,8 @@ import (
 // multiple endpoints. Clone() should be called in such cases so that
 // modifications to the Data field do not affect other copies.
 type PacketBuffer struct {
+	_ noCopy
+
 	// PacketBufferEntry is used to build an intrusive list of
 	// PacketBuffers.
 	PacketBufferEntry
@@ -82,7 +84,32 @@ type PacketBuffer struct {
 // VectorisedView but does not deep copy the underlying bytes.
 //
 // Clone also does not deep copy any of its other fields.
-func (pk PacketBuffer) Clone() PacketBuffer {
-	pk.Data = pk.Data.Clone(nil)
-	return pk
+//
+// FIXME(b/153685824): Data gets copied but not other header references.
+func (pk *PacketBuffer) Clone() *PacketBuffer {
+	return &PacketBuffer{
+		PacketBufferEntry:     pk.PacketBufferEntry,
+		Data:                  pk.Data.Clone(nil),
+		Header:                pk.Header,
+		LinkHeader:            pk.LinkHeader,
+		NetworkHeader:         pk.NetworkHeader,
+		TransportHeader:       pk.TransportHeader,
+		Hash:                  pk.Hash,
+		Owner:                 pk.Owner,
+		EgressRoute:           pk.EgressRoute,
+		GSOOptions:            pk.GSOOptions,
+		NetworkProtocolNumber: pk.NetworkProtocolNumber,
+		NatDone:               pk.NatDone,
+	}
 }
+
+// noCopy may be embedded into structs which must not be copied
+// after the first use.
+//
+// See https://golang.org/issues/8005#issuecomment-190753527
+// for details.
+type noCopy struct{}
+
+// Lock is a no-op used by -copylocks checker from `go vet`.
+func (*noCopy) Lock()   {}
+func (*noCopy) Unlock() {}
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go
index db89234e8..94f177841 100644
--- a/pkg/tcpip/stack/registration.go
+++ b/pkg/tcpip/stack/registration.go
@@ -67,12 +67,12 @@ type TransportEndpoint interface {
 	// this transport endpoint. It sets pkt.TransportHeader.
 	//
 	// HandlePacket takes ownership of pkt.
-	HandlePacket(r *Route, id TransportEndpointID, pkt PacketBuffer)
+	HandlePacket(r *Route, id TransportEndpointID, pkt *PacketBuffer)
 
 	// HandleControlPacket is called by the stack when new control (e.g.
 	// ICMP) packets arrive to this transport endpoint.
 	// HandleControlPacket takes ownership of pkt.
-	HandleControlPacket(id TransportEndpointID, typ ControlType, extra uint32, pkt PacketBuffer)
+	HandleControlPacket(id TransportEndpointID, typ ControlType, extra uint32, pkt *PacketBuffer)
 
 	// Abort initiates an expedited endpoint teardown. It puts the endpoint
 	// in a closed state and frees all resources associated with it. This
@@ -100,7 +100,7 @@ type RawTransportEndpoint interface {
 	// layer up.
 	//
 	// HandlePacket takes ownership of pkt.
-	HandlePacket(r *Route, pkt PacketBuffer)
+	HandlePacket(r *Route, pkt *PacketBuffer)
 }
 
 // PacketEndpoint is the interface that needs to be implemented by packet
@@ -118,7 +118,7 @@ type PacketEndpoint interface {
 	// should construct its own ethernet header for applications.
 	//
 	// HandlePacket takes ownership of pkt.
-	HandlePacket(nicID tcpip.NICID, addr tcpip.LinkAddress, netProto tcpip.NetworkProtocolNumber, pkt PacketBuffer)
+	HandlePacket(nicID tcpip.NICID, addr tcpip.LinkAddress, netProto tcpip.NetworkProtocolNumber, pkt *PacketBuffer)
 }
 
 // TransportProtocol is the interface that needs to be implemented by transport
@@ -150,7 +150,7 @@ type TransportProtocol interface {
 	// stats purposes only).
 	//
 	// HandleUnknownDestinationPacket takes ownership of pkt.
-	HandleUnknownDestinationPacket(r *Route, id TransportEndpointID, pkt PacketBuffer) bool
+	HandleUnknownDestinationPacket(r *Route, id TransportEndpointID, pkt *PacketBuffer) bool
 
 	// SetOption allows enabling/disabling protocol specific features.
 	// SetOption returns an error if the option is not supported or the
@@ -180,7 +180,7 @@ type TransportDispatcher interface {
 	// pkt.NetworkHeader must be set before calling DeliverTransportPacket.
 	//
 	// DeliverTransportPacket takes ownership of pkt.
-	DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt PacketBuffer)
+	DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer)
 
 	// DeliverTransportControlPacket delivers control packets to the
 	// appropriate transport protocol endpoint.
@@ -189,7 +189,7 @@ type TransportDispatcher interface {
 	// DeliverTransportControlPacket.
 	//
 	// DeliverTransportControlPacket takes ownership of pkt.
-	DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt PacketBuffer)
+	DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt *PacketBuffer)
 }
 
 // PacketLooping specifies where an outbound packet should be sent.
@@ -242,7 +242,7 @@ type NetworkEndpoint interface {
 	// WritePacket writes a packet to the given destination address and
 	// protocol. It takes ownership of pkt. pkt.TransportHeader must have already
 	// been set.
-	WritePacket(r *Route, gso *GSO, params NetworkHeaderParams, pkt PacketBuffer) *tcpip.Error
+	WritePacket(r *Route, gso *GSO, params NetworkHeaderParams, pkt *PacketBuffer) *tcpip.Error
 
 	// WritePackets writes packets to the given destination address and
 	// protocol. pkts must not be zero length. It takes ownership of pkts and
@@ -251,7 +251,7 @@ type NetworkEndpoint interface {
 
 	// WriteHeaderIncludedPacket writes a packet that includes a network
 	// header to the given destination address. It takes ownership of pkt.
-	WriteHeaderIncludedPacket(r *Route, pkt PacketBuffer) *tcpip.Error
+	WriteHeaderIncludedPacket(r *Route, pkt *PacketBuffer) *tcpip.Error
 
 	// ID returns the network protocol endpoint ID.
 	ID() *NetworkEndpointID
@@ -266,7 +266,7 @@ type NetworkEndpoint interface {
 	// this network endpoint. It sets pkt.NetworkHeader.
 	//
 	// HandlePacket takes ownership of pkt.
-	HandlePacket(r *Route, pkt PacketBuffer)
+	HandlePacket(r *Route, pkt *PacketBuffer)
 
 	// Close is called when the endpoint is reomved from a stack.
 	Close()
@@ -327,7 +327,7 @@ type NetworkDispatcher interface {
 	// packets sent via loopback), and won't have the field set.
 	//
 	// DeliverNetworkPacket takes ownership of pkt.
-	DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt PacketBuffer)
+	DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer)
 }
 
 // LinkEndpointCapabilities is the type associated with the capabilities
@@ -389,7 +389,7 @@ type LinkEndpoint interface {
 	// To participate in transparent bridging, a LinkEndpoint implementation
 	// should call eth.Encode with header.EthernetFields.SrcAddr set to
 	// r.LocalLinkAddress if it is provided.
-	WritePacket(r *Route, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt PacketBuffer) *tcpip.Error
+	WritePacket(r *Route, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) *tcpip.Error
 
 	// WritePackets writes packets with the given protocol through the
 	// given route. pkts must not be zero length. It takes ownership of pkts and
@@ -431,7 +431,7 @@ type InjectableLinkEndpoint interface {
 	LinkEndpoint
 
 	// InjectInbound injects an inbound packet.
-	InjectInbound(protocol tcpip.NetworkProtocolNumber, pkt PacketBuffer)
+	InjectInbound(protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer)
 
 	// InjectOutbound writes a fully formed outbound packet directly to the
 	// link.
diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go
index 3d0e5cc6e..f5b6ca0b9 100644
--- a/pkg/tcpip/stack/route.go
+++ b/pkg/tcpip/stack/route.go
@@ -153,7 +153,7 @@ func (r *Route) IsResolutionRequired() bool {
 }
 
 // WritePacket writes the packet through the given route.
-func (r *Route) WritePacket(gso *GSO, params NetworkHeaderParams, pkt PacketBuffer) *tcpip.Error {
+func (r *Route) WritePacket(gso *GSO, params NetworkHeaderParams, pkt *PacketBuffer) *tcpip.Error {
 	if !r.ref.isValidForOutgoing() {
 		return tcpip.ErrInvalidEndpointState
 	}
@@ -199,7 +199,7 @@ func (r *Route) WritePackets(gso *GSO, pkts PacketBufferList, params NetworkHead
 
 // WriteHeaderIncludedPacket writes a packet already containing a network
 // header through the given route.
-func (r *Route) WriteHeaderIncludedPacket(pkt PacketBuffer) *tcpip.Error {
+func (r *Route) WriteHeaderIncludedPacket(pkt *PacketBuffer) *tcpip.Error {
 	if !r.ref.isValidForOutgoing() {
 		return tcpip.ErrInvalidEndpointState
 	}
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 0ab4c3e19..8af06cb9a 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -52,7 +52,7 @@ const (
 
 type transportProtocolState struct {
 	proto          TransportProtocol
-	defaultHandler func(r *Route, id TransportEndpointID, pkt PacketBuffer) bool
+	defaultHandler func(r *Route, id TransportEndpointID, pkt *PacketBuffer) bool
 }
 
 // TCPProbeFunc is the expected function type for a TCP probe function to be
@@ -778,7 +778,7 @@ 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, PacketBuffer) bool) {
+func (s *Stack) SetTransportProtocolHandler(p tcpip.TransportProtocolNumber, h func(*Route, TransportEndpointID, *PacketBuffer) bool) {
 	state := s.transportProtocols[p]
 	if state != nil {
 		state.defaultHandler = h
diff --git a/pkg/tcpip/stack/transport_demuxer.go b/pkg/tcpip/stack/transport_demuxer.go
index 9a33ed375..e09866405 100644
--- a/pkg/tcpip/stack/transport_demuxer.go
+++ b/pkg/tcpip/stack/transport_demuxer.go
@@ -152,7 +152,7 @@ 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, pkt PacketBuffer) {
+func (epsByNIC *endpointsByNIC) handlePacket(r *Route, id TransportEndpointID, pkt *PacketBuffer) {
 	epsByNIC.mu.RLock()
 
 	mpep, ok := epsByNIC.endpoints[r.ref.nic.ID()]
@@ -183,7 +183,7 @@ func (epsByNIC *endpointsByNIC) handlePacket(r *Route, id TransportEndpointID, p
 }
 
 // HandleControlPacket implements stack.TransportEndpoint.HandleControlPacket.
-func (epsByNIC *endpointsByNIC) handleControlPacket(n *NIC, id TransportEndpointID, typ ControlType, extra uint32, pkt PacketBuffer) {
+func (epsByNIC *endpointsByNIC) handleControlPacket(n *NIC, id TransportEndpointID, typ ControlType, extra uint32, pkt *PacketBuffer) {
 	epsByNIC.mu.RLock()
 	defer epsByNIC.mu.RUnlock()
 
@@ -251,7 +251,7 @@ type transportDemuxer struct {
 // the dispatcher to delivery packets to the QueuePacket method instead of
 // calling HandlePacket directly on the endpoint.
 type queuedTransportProtocol interface {
-	QueuePacket(r *Route, ep TransportEndpoint, id TransportEndpointID, pkt PacketBuffer)
+	QueuePacket(r *Route, ep TransportEndpoint, id TransportEndpointID, pkt *PacketBuffer)
 }
 
 func newTransportDemuxer(stack *Stack) *transportDemuxer {
@@ -379,7 +379,7 @@ func selectEndpoint(id TransportEndpointID, mpep *multiPortEndpoint, seed uint32
 	return mpep.endpoints[idx]
 }
 
-func (ep *multiPortEndpoint) handlePacketAll(r *Route, id TransportEndpointID, pkt PacketBuffer) {
+func (ep *multiPortEndpoint) handlePacketAll(r *Route, id TransportEndpointID, pkt *PacketBuffer) {
 	ep.mu.RLock()
 	queuedProtocol, mustQueue := ep.demux.queuedProtocols[protocolIDs{ep.netProto, ep.transProto}]
 	// HandlePacket takes ownership of pkt, so each endpoint needs
@@ -470,7 +470,7 @@ func (d *transportDemuxer) unregisterEndpoint(netProtos []tcpip.NetworkProtocolN
 // deliverPacket attempts to find one or more matching transport endpoints, and
 // then, if matches are found, delivers the packet to them. Returns true if
 // the packet no longer needs to be handled.
-func (d *transportDemuxer) deliverPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt PacketBuffer, id TransportEndpointID) bool {
+func (d *transportDemuxer) deliverPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer, id TransportEndpointID) bool {
 	eps, ok := d.protocol[protocolIDs{r.NetProto, protocol}]
 	if !ok {
 		return false
@@ -520,7 +520,7 @@ func (d *transportDemuxer) deliverPacket(r *Route, protocol tcpip.TransportProto
 
 // deliverRawPacket attempts to deliver the given packet and returns whether it
 // was delivered successfully.
-func (d *transportDemuxer) deliverRawPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt PacketBuffer) bool {
+func (d *transportDemuxer) deliverRawPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) bool {
 	eps, ok := d.protocol[protocolIDs{r.NetProto, protocol}]
 	if !ok {
 		return false
@@ -544,7 +544,7 @@ 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, pkt PacketBuffer, id TransportEndpointID) bool {
+func (d *transportDemuxer) deliverControlPacket(n *NIC, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt *PacketBuffer, id TransportEndpointID) bool {
 	eps, ok := d.protocol[protocolIDs{net, trans}]
 	if !ok {
 		return false