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

1 files changed, 17 insertions, 17 deletions

diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 64046cbbf..9cd7592f4 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -129,7 +129,7 @@ func (e *endpoint) NetworkProtocolNumber() tcpip.NetworkProtocolNumber {
 // packet's stated length matches the length of the header+payload. mtu
 // includes the IP header and options. This does not support the DontFragment
 // IP flag.
-func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu int, pkt stack.PacketBuffer) *tcpip.Error {
+func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu int, pkt *stack.PacketBuffer) *tcpip.Error {
 	// This packet is too big, it needs to be fragmented.
 	ip := header.IPv4(pkt.Header.View())
 	flags := ip.Flags()
@@ -169,7 +169,7 @@ func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu int,
 		if i > 0 {
 			newPayload := pkt.Data.Clone(nil)
 			newPayload.CapLength(innerMTU)
-			if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, stack.PacketBuffer{
+			if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, &stack.PacketBuffer{
 				Header:        pkt.Header,
 				Data:          newPayload,
 				NetworkHeader: buffer.View(h),
@@ -188,7 +188,7 @@ func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu int,
 			newPayload := pkt.Data.Clone(nil)
 			newPayloadLength := outerMTU - pkt.Header.UsedLength()
 			newPayload.CapLength(newPayloadLength)
-			if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, stack.PacketBuffer{
+			if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, &stack.PacketBuffer{
 				Header:        pkt.Header,
 				Data:          newPayload,
 				NetworkHeader: buffer.View(h),
@@ -202,7 +202,7 @@ func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu int,
 			startOfHdr := pkt.Header
 			startOfHdr.TrimBack(pkt.Header.UsedLength() - outerMTU)
 			emptyVV := buffer.NewVectorisedView(0, []buffer.View{})
-			if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, stack.PacketBuffer{
+			if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, &stack.PacketBuffer{
 				Header:        startOfHdr,
 				Data:          emptyVV,
 				NetworkHeader: buffer.View(h),
@@ -245,7 +245,7 @@ func (e *endpoint) addIPHeader(r *stack.Route, hdr *buffer.Prependable, payloadS
 }
 
 // WritePacket writes a packet to the given destination address and protocol.
-func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, pkt stack.PacketBuffer) *tcpip.Error {
+func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, pkt *stack.PacketBuffer) *tcpip.Error {
 	ip := e.addIPHeader(r, &pkt.Header, pkt.Data.Size(), params)
 	pkt.NetworkHeader = buffer.View(ip)
 
@@ -253,7 +253,7 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.Netw
 	// iptables filtering. All packets that reach here are locally
 	// generated.
 	ipt := e.stack.IPTables()
-	if ok := ipt.Check(stack.Output, &pkt, gso, r, "", nicName); !ok {
+	if ok := ipt.Check(stack.Output, pkt, gso, r, "", nicName); !ok {
 		// iptables is telling us to drop the packet.
 		return nil
 	}
@@ -271,9 +271,9 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.Netw
 			views := make([]buffer.View, 1, 1+len(pkt.Data.Views()))
 			views[0] = pkt.Header.View()
 			views = append(views, pkt.Data.Views()...)
-			packet := stack.PacketBuffer{
-				Data: buffer.NewVectorisedView(len(views[0])+pkt.Data.Size(), views)}
-			ep.HandlePacket(&route, packet)
+			ep.HandlePacket(&route, &stack.PacketBuffer{
+				Data: buffer.NewVectorisedView(len(views[0])+pkt.Data.Size(), views),
+			})
 			return nil
 		}
 	}
@@ -286,7 +286,7 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.Netw
 		views = append(views, pkt.Data.Views()...)
 		loopedR := r.MakeLoopedRoute()
 
-		e.HandlePacket(&loopedR, stack.PacketBuffer{
+		e.HandlePacket(&loopedR, &stack.PacketBuffer{
 			Data: buffer.NewVectorisedView(len(views[0])+pkt.Data.Size(), views),
 		})
 
@@ -351,14 +351,14 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
 				views := make([]buffer.View, 1, 1+len(pkt.Data.Views()))
 				views[0] = pkt.Header.View()
 				views = append(views, pkt.Data.Views()...)
-				packet := stack.PacketBuffer{
-					Data: buffer.NewVectorisedView(len(views[0])+pkt.Data.Size(), views)}
-				ep.HandlePacket(&route, packet)
+				ep.HandlePacket(&route, &stack.PacketBuffer{
+					Data: buffer.NewVectorisedView(len(views[0])+pkt.Data.Size(), views),
+				})
 				n++
 				continue
 			}
 		}
-		if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, *pkt); err != nil {
+		if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, pkt); err != nil {
 			r.Stats().IP.PacketsSent.IncrementBy(uint64(n))
 			return n, err
 		}
@@ -370,7 +370,7 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
 
 // WriteHeaderIncludedPacket writes a packet already containing a network
 // header through the given route.
-func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt stack.PacketBuffer) *tcpip.Error {
+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)
@@ -426,7 +426,7 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt stack.PacketBuf
 
 // HandlePacket is called by the link layer when new ipv4 packets arrive for
 // this endpoint.
-func (e *endpoint) HandlePacket(r *stack.Route, pkt stack.PacketBuffer) {
+func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
 	headerView, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
 	if !ok {
 		r.Stats().IP.MalformedPacketsReceived.Increment()
@@ -447,7 +447,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt stack.PacketBuffer) {
 	// iptables filtering. All packets that reach here are intended for
 	// this machine and will not be forwarded.
 	ipt := e.stack.IPTables()
-	if ok := ipt.Check(stack.Input, &pkt, nil, nil, "", ""); !ok {
+	if ok := ipt.Check(stack.Input, pkt, nil, nil, "", ""); !ok {
 		// iptables is telling us to drop the packet.
 		return
 	}