Pass PacketBuffer as pointer.

Historically we've been passing PacketBuffer by shallow copying through out
the stack. Right now, this is only correct as the caller would not use
PacketBuffer after passing into the next layer in netstack.

With new buffer management effort in gVisor/netstack, PacketBuffer will
own a Buffer (to be added). Internally, both PacketBuffer and Buffer may
have pointers and shallow copying shouldn't be used.

Updates #2404.

PiperOrigin-RevId: 314610879

7 files changed, 14 insertions, 14 deletions

diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index e4a06c9e1..7da93dcc4 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -833,13 +833,13 @@ func sendTCP(r *stack.Route, tf tcpFields, data buffer.VectorisedView, gso *stac
 		return sendTCPBatch(r, tf, data, gso, owner)
 	}
 
-	pkt := stack.PacketBuffer{
+	pkt := &stack.PacketBuffer{
 		Header: buffer.NewPrependable(header.TCPMinimumSize + int(r.MaxHeaderLength()) + optLen),
 		Data:   data,
 		Hash:   tf.txHash,
 		Owner:  owner,
 	}
-	buildTCPHdr(r, tf, &pkt, gso)
+	buildTCPHdr(r, tf, pkt, gso)
 
 	if tf.ttl == 0 {
 		tf.ttl = r.DefaultTTL()
diff --git a/pkg/tcpip/transport/tcp/dispatcher.go b/pkg/tcpip/transport/tcp/dispatcher.go
index 6062ca916..047704c80 100644
--- a/pkg/tcpip/transport/tcp/dispatcher.go
+++ b/pkg/tcpip/transport/tcp/dispatcher.go
@@ -186,7 +186,7 @@ func (d *dispatcher) wait() {
 	}
 }
 
-func (d *dispatcher) queuePacket(r *stack.Route, stackEP stack.TransportEndpoint, id stack.TransportEndpointID, pkt stack.PacketBuffer) {
+func (d *dispatcher) queuePacket(r *stack.Route, stackEP stack.TransportEndpoint, id stack.TransportEndpointID, pkt *stack.PacketBuffer) {
 	ep := stackEP.(*endpoint)
 	s := newSegment(r, id, pkt)
 	if !s.parse() {
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index b5ba972f1..d048ef90c 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -2462,7 +2462,7 @@ func (e *endpoint) GetRemoteAddress() (tcpip.FullAddress, *tcpip.Error) {
 	}, nil
 }
 
-func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, pkt stack.PacketBuffer) {
+func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, pkt *stack.PacketBuffer) {
 	// TCP HandlePacket is not required anymore as inbound packets first
 	// land at the Dispatcher which then can either delivery using the
 	// worker go routine or directly do the invoke the tcp processing inline
@@ -2481,7 +2481,7 @@ func (e *endpoint) enqueueSegment(s *segment) bool {
 }
 
 // HandleControlPacket implements stack.TransportEndpoint.HandleControlPacket.
-func (e *endpoint) HandleControlPacket(id stack.TransportEndpointID, typ stack.ControlType, extra uint32, pkt stack.PacketBuffer) {
+func (e *endpoint) HandleControlPacket(id stack.TransportEndpointID, typ stack.ControlType, extra uint32, pkt *stack.PacketBuffer) {
 	switch typ {
 	case stack.ControlPacketTooBig:
 		e.sndBufMu.Lock()
diff --git a/pkg/tcpip/transport/tcp/forwarder.go b/pkg/tcpip/transport/tcp/forwarder.go
index 704d01c64..070b634b4 100644
--- a/pkg/tcpip/transport/tcp/forwarder.go
+++ b/pkg/tcpip/transport/tcp/forwarder.go
@@ -61,7 +61,7 @@ func NewForwarder(s *stack.Stack, rcvWnd, maxInFlight int, handler func(*Forward
 //
 // This function is expected to be passed as an argument to the
 // stack.SetTransportProtocolHandler function.
-func (f *Forwarder) HandlePacket(r *stack.Route, id stack.TransportEndpointID, pkt stack.PacketBuffer) bool {
+func (f *Forwarder) HandlePacket(r *stack.Route, id stack.TransportEndpointID, pkt *stack.PacketBuffer) bool {
 	s := newSegment(r, id, pkt)
 	defer s.decRef()
 
diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go
index 2a2a7ddeb..c827d0277 100644
--- a/pkg/tcpip/transport/tcp/protocol.go
+++ b/pkg/tcpip/transport/tcp/protocol.go
@@ -206,7 +206,7 @@ func (*protocol) ParsePorts(v buffer.View) (src, dst uint16, err *tcpip.Error) {
 // to a specific processing queue. Each queue is serviced by its own processor
 // goroutine which is responsible for dequeuing and doing full TCP dispatch of
 // the packet.
-func (p *protocol) QueuePacket(r *stack.Route, ep stack.TransportEndpoint, id stack.TransportEndpointID, pkt stack.PacketBuffer) {
+func (p *protocol) QueuePacket(r *stack.Route, ep stack.TransportEndpoint, id stack.TransportEndpointID, pkt *stack.PacketBuffer) {
 	p.dispatcher.queuePacket(r, ep, id, pkt)
 }
 
@@ -217,7 +217,7 @@ func (p *protocol) QueuePacket(r *stack.Route, ep stack.TransportEndpoint, id st
 // a reset is sent in response to any incoming segment except another reset. In
 // particular, SYNs addressed to a non-existent connection are rejected by this
 // means."
-func (*protocol) HandleUnknownDestinationPacket(r *stack.Route, id stack.TransportEndpointID, pkt stack.PacketBuffer) bool {
+func (*protocol) HandleUnknownDestinationPacket(r *stack.Route, id stack.TransportEndpointID, pkt *stack.PacketBuffer) bool {
 	s := newSegment(r, id, pkt)
 	defer s.decRef()
 
diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go
index 074edded6..0c099e2fd 100644
--- a/pkg/tcpip/transport/tcp/segment.go
+++ b/pkg/tcpip/transport/tcp/segment.go
@@ -60,7 +60,7 @@ type segment struct {
 	xmitCount uint32
 }
 
-func newSegment(r *stack.Route, id stack.TransportEndpointID, pkt stack.PacketBuffer) *segment {
+func newSegment(r *stack.Route, id stack.TransportEndpointID, pkt *stack.PacketBuffer) *segment {
 	s := &segment{
 		refCnt: 1,
 		id:     id,
diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go
index 7b1d72cf4..9721f6caf 100644
--- a/pkg/tcpip/transport/tcp/testing/context/context.go
+++ b/pkg/tcpip/transport/tcp/testing/context/context.go
@@ -316,7 +316,7 @@ func (c *Context) SendICMPPacket(typ header.ICMPv4Type, code uint8, p1, p2 []byt
 	copy(icmp[header.ICMPv4PayloadOffset:], p2)
 
 	// Inject packet.
-	c.linkEP.InjectInbound(ipv4.ProtocolNumber, stack.PacketBuffer{
+	c.linkEP.InjectInbound(ipv4.ProtocolNumber, &stack.PacketBuffer{
 		Data: buf.ToVectorisedView(),
 	})
 }
@@ -372,7 +372,7 @@ func (c *Context) BuildSegmentWithAddrs(payload []byte, h *Headers, src, dst tcp
 // SendSegment sends a TCP segment that has already been built and written to a
 // buffer.VectorisedView.
 func (c *Context) SendSegment(s buffer.VectorisedView) {
-	c.linkEP.InjectInbound(ipv4.ProtocolNumber, stack.PacketBuffer{
+	c.linkEP.InjectInbound(ipv4.ProtocolNumber, &stack.PacketBuffer{
 		Data: s,
 	})
 }
@@ -380,7 +380,7 @@ func (c *Context) SendSegment(s buffer.VectorisedView) {
 // SendPacket builds and sends a TCP segment(with the provided payload & TCP
 // headers) in an IPv4 packet via the link layer endpoint.
 func (c *Context) SendPacket(payload []byte, h *Headers) {
-	c.linkEP.InjectInbound(ipv4.ProtocolNumber, stack.PacketBuffer{
+	c.linkEP.InjectInbound(ipv4.ProtocolNumber, &stack.PacketBuffer{
 		Data: c.BuildSegment(payload, h),
 	})
 }
@@ -389,7 +389,7 @@ func (c *Context) SendPacket(payload []byte, h *Headers) {
 // & TCPheaders) in an IPv4 packet via the link layer endpoint using the
 // provided source and destination IPv4 addresses.
 func (c *Context) SendPacketWithAddrs(payload []byte, h *Headers, src, dst tcpip.Address) {
-	c.linkEP.InjectInbound(ipv4.ProtocolNumber, stack.PacketBuffer{
+	c.linkEP.InjectInbound(ipv4.ProtocolNumber, &stack.PacketBuffer{
 		Data: c.BuildSegmentWithAddrs(payload, h, src, dst),
 	})
 }
@@ -564,7 +564,7 @@ func (c *Context) SendV6PacketWithAddrs(payload []byte, h *Headers, src, dst tcp
 	t.SetChecksum(^t.CalculateChecksum(xsum))
 
 	// Inject packet.
-	c.linkEP.InjectInbound(ipv6.ProtocolNumber, stack.PacketBuffer{
+	c.linkEP.InjectInbound(ipv6.ProtocolNumber, &stack.PacketBuffer{
 		Data: buf.ToVectorisedView(),
 	})
 }