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

1 files changed, 37 insertions, 27 deletions

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.