Deep copy dispatcher views.

When VectorisedViews were passed up the stack from packet_dispatchers, we were
passing a sub-slice of the dispatcher's views fields. The dispatchers then
immediately set those views to nil.

This wasn't caught before because every implementer copied the data in these
views before returning.

PiperOrigin-RevId: 277615351

1 files changed, 16 insertions, 0 deletions

diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go
index 94015ba54..d7c124e81 100644
--- a/pkg/tcpip/stack/registration.go
+++ b/pkg/tcpip/stack/registration.go
@@ -65,10 +65,14 @@ type TransportEndpoint interface {
 
 	// HandlePacket is called by the stack when new packets arrive to
 	// this transport endpoint.
+	//
+	// HandlePacket takes ownership of vv.
 	HandlePacket(r *Route, id TransportEndpointID, vv buffer.VectorisedView)
 
 	// 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)
 
 	// Close puts the endpoint in a closed state and frees all resources
@@ -94,6 +98,8 @@ type RawTransportEndpoint interface {
 	// HandlePacket is called by the stack when new packets arrive to
 	// 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)
 }
 
@@ -110,6 +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)
 }
 
@@ -160,10 +168,14 @@ 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.
+	//
+	// DeliverTransportPacket takes ownership of vv and netHeader.
 	DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView)
 
 	// 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)
 }
 
@@ -237,6 +249,8 @@ type NetworkEndpoint interface {
 
 	// HandlePacket is called by the link layer when new packets arrive to
 	// this network endpoint.
+	//
+	// HandlePacket takes ownership of vv.
 	HandlePacket(r *Route, vv buffer.VectorisedView)
 
 	// Close is called when the endpoint is reomved from a stack.
@@ -282,6 +296,8 @@ 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.
+	//
+	// DeliverNetworkPacket takes ownership of vv and linkHeader.
 	DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView, linkHeader buffer.View)
 }