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

4 files changed, 5 insertions, 19 deletions

diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index 114a69b4e..33405eb7d 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -31,9 +31,6 @@ type icmpPacket struct {
 	senderAddress tcpip.FullAddress
 	data          buffer.VectorisedView `state:".(buffer.VectorisedView)"`
 	timestamp     int64
-	// views is used as buffer for data when its length is large
-	// enough to store a VectorisedView.
-	views [8]buffer.View `state:"nosave"`
 }
 
 type endpointState int
@@ -767,7 +764,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, vv
 		},
 	}
 
-	pkt.data = vv.Clone(pkt.views[:])
+	pkt.data = vv
 
 	e.rcvList.PushBack(pkt)
 	e.rcvBufSize += pkt.data.Size()
diff --git a/pkg/tcpip/transport/packet/endpoint.go b/pkg/tcpip/transport/packet/endpoint.go
index 73cdaa265..ead83b83d 100644
--- a/pkg/tcpip/transport/packet/endpoint.go
+++ b/pkg/tcpip/transport/packet/endpoint.go
@@ -41,10 +41,6 @@ type packet struct {
 	// data holds the actual packet data, including any headers and
 	// payload.
 	data buffer.VectorisedView `state:".(buffer.VectorisedView)"`
-	// views is pre-allocated space to back data. As long as the packet is
-	// made up of fewer than 8 buffer.Views, no extra allocation is
-	// necessary to store packet data.
-	views [8]buffer.View `state:"nosave"`
 	// timestampNS is the unix time at which the packet was received.
 	timestampNS int64
 	// senderAddr is the network address of the sender.
@@ -310,7 +306,7 @@ func (ep *endpoint) HandlePacket(nicid tcpip.NICID, localAddr tcpip.LinkAddress,
 
 	if ep.cooked {
 		// Cooked packets can simply be queued.
-		packet.data = vv.Clone(packet.views[:])
+		packet.data = vv
 	} else {
 		// Raw packets need their ethernet headers prepended before
 		// queueing.
@@ -328,7 +324,7 @@ func (ep *endpoint) HandlePacket(nicid tcpip.NICID, localAddr tcpip.LinkAddress,
 		}
 		combinedVV := buffer.View(ethHeader).ToVectorisedView()
 		combinedVV.Append(vv)
-		packet.data = combinedVV.Clone(packet.views[:])
+		packet.data = combinedVV
 	}
 	packet.timestampNS = ep.stack.NowNanoseconds()
 
diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go
index 951d317ed..23922a30e 100644
--- a/pkg/tcpip/transport/raw/endpoint.go
+++ b/pkg/tcpip/transport/raw/endpoint.go
@@ -42,10 +42,6 @@ type rawPacket struct {
 	// data holds the actual packet data, including any headers and
 	// payload.
 	data buffer.VectorisedView `state:".(buffer.VectorisedView)"`
-	// views is pre-allocated space to back data. As long as the packet is
-	// made up of fewer than 8 buffer.Views, no extra allocation is
-	// necessary to store packet data.
-	views [8]buffer.View `state:"nosave"`
 	// timestampNS is the unix time at which the packet was received.
 	timestampNS int64
 	// senderAddr is the network address of the sender.
@@ -609,7 +605,7 @@ func (e *endpoint) HandlePacket(route *stack.Route, netHeader buffer.View, vv bu
 
 	combinedVV := netHeader.ToVectorisedView()
 	combinedVV.Append(vv)
-	pkt.data = combinedVV.Clone(pkt.views[:])
+	pkt.data = combinedVV
 	pkt.timestampNS = e.stack.NowNanoseconds()
 
 	e.rcvList.PushBack(pkt)
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 68977dc25..03bd5c8fd 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -31,9 +31,6 @@ type udpPacket struct {
 	senderAddress tcpip.FullAddress
 	data          buffer.VectorisedView `state:".(buffer.VectorisedView)"`
 	timestamp     int64
-	// views is used as buffer for data when its length is large
-	// enough to store a VectorisedView.
-	views [8]buffer.View `state:"nosave"`
 }
 
 // EndpointState represents the state of a UDP endpoint.
@@ -1202,7 +1199,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, vv
 			Port: hdr.SourcePort(),
 		},
 	}
-	pkt.data = vv.Clone(pkt.views[:])
+	pkt.data = vv
 	e.rcvList.PushBack(pkt)
 	e.rcvBufSize += vv.Size()