Merge release-20200810.0-23-g47515f475 (automated)

2 files changed, 45 insertions, 57 deletions

diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index ded91d83a..39ae19295 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -83,7 +83,7 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme
 		return
 	}
 	h := header.ICMPv6(v)
-	iph := header.IPv6(pkt.NetworkHeader)
+	iph := header.IPv6(pkt.NetworkHeader().View())
 
 	// Validate ICMPv6 checksum before processing the packet.
 	//
@@ -276,8 +276,10 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme
 		optsSerializer := header.NDPOptionsSerializer{
 			header.NDPTargetLinkLayerAddressOption(r.LocalLinkAddress),
 		}
-		hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + header.ICMPv6NeighborAdvertMinimumSize + int(optsSerializer.Length()))
-		packet := header.ICMPv6(hdr.Prepend(header.ICMPv6NeighborAdvertSize))
+		pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+			ReserveHeaderBytes: int(r.MaxHeaderLength()) + header.ICMPv6NeighborAdvertMinimumSize + int(optsSerializer.Length()),
+		})
+		packet := header.ICMPv6(pkt.TransportHeader().Push(header.ICMPv6NeighborAdvertSize))
 		packet.SetType(header.ICMPv6NeighborAdvert)
 		na := header.NDPNeighborAdvert(packet.NDPPayload())
 		na.SetSolicitedFlag(solicited)
@@ -293,9 +295,7 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme
 		//
 		// The IP Hop Limit field has a value of 255, i.e., the packet
 		// could not possibly have been forwarded by a router.
-		if err := r.WritePacket(nil /* gso */, stack.NetworkHeaderParams{Protocol: header.ICMPv6ProtocolNumber, TTL: header.NDPHopLimit, TOS: stack.DefaultTOS}, &stack.PacketBuffer{
-			Header: hdr,
-		}); err != nil {
+		if err := r.WritePacket(nil /* gso */, stack.NetworkHeaderParams{Protocol: header.ICMPv6ProtocolNumber, TTL: header.NDPHopLimit, TOS: stack.DefaultTOS}, pkt); err != nil {
 			sent.Dropped.Increment()
 			return
 		}
@@ -384,7 +384,7 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme
 
 	case header.ICMPv6EchoRequest:
 		received.EchoRequest.Increment()
-		icmpHdr, ok := pkt.Data.PullUp(header.ICMPv6EchoMinimumSize)
+		icmpHdr, ok := pkt.TransportHeader().Consume(header.ICMPv6EchoMinimumSize)
 		if !ok {
 			received.Invalid.Increment()
 			return
@@ -409,16 +409,15 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme
 		// Use the link address from the source of the original packet.
 		r.ResolveWith(remoteLinkAddr)
 
-		pkt.Data.TrimFront(header.ICMPv6EchoMinimumSize)
-		hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + header.ICMPv6EchoMinimumSize)
-		packet := header.ICMPv6(hdr.Prepend(header.ICMPv6EchoMinimumSize))
+		replyPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+			ReserveHeaderBytes: int(r.MaxHeaderLength()) + header.ICMPv6EchoMinimumSize,
+			Data:               pkt.Data,
+		})
+		packet := header.ICMPv6(replyPkt.TransportHeader().Push(header.ICMPv6EchoMinimumSize))
 		copy(packet, icmpHdr)
 		packet.SetType(header.ICMPv6EchoReply)
 		packet.SetChecksum(header.ICMPv6Checksum(packet, r.LocalAddress, r.RemoteAddress, pkt.Data))
-		if err := r.WritePacket(nil /* gso */, stack.NetworkHeaderParams{Protocol: header.ICMPv6ProtocolNumber, TTL: r.DefaultTTL(), TOS: stack.DefaultTOS}, &stack.PacketBuffer{
-			Header: hdr,
-			Data:   pkt.Data,
-		}); err != nil {
+		if err := r.WritePacket(nil /* gso */, stack.NetworkHeaderParams{Protocol: header.ICMPv6ProtocolNumber, TTL: r.DefaultTTL(), TOS: stack.DefaultTOS}, replyPkt); err != nil {
 			sent.Dropped.Increment()
 			return
 		}
@@ -539,17 +538,19 @@ func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, remoteLinkAdd
 		r.RemoteLinkAddress = header.EthernetAddressFromMulticastIPv6Address(snaddr)
 	}
 
-	hdr := buffer.NewPrependable(int(linkEP.MaxHeaderLength()) + header.IPv6MinimumSize + header.ICMPv6NeighborAdvertSize)
-	pkt := header.ICMPv6(hdr.Prepend(header.ICMPv6NeighborAdvertSize))
-	pkt.SetType(header.ICMPv6NeighborSolicit)
-	copy(pkt[icmpV6OptOffset-len(addr):], addr)
-	pkt[icmpV6OptOffset] = ndpOptSrcLinkAddr
-	pkt[icmpV6LengthOffset] = 1
-	copy(pkt[icmpV6LengthOffset+1:], linkEP.LinkAddress())
-	pkt.SetChecksum(header.ICMPv6Checksum(pkt, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{}))
-
-	length := uint16(hdr.UsedLength())
-	ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize))
+	pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+		ReserveHeaderBytes: int(linkEP.MaxHeaderLength()) + header.IPv6MinimumSize + header.ICMPv6NeighborAdvertSize,
+	})
+	icmpHdr := header.ICMPv6(pkt.TransportHeader().Push(header.ICMPv6NeighborAdvertSize))
+	icmpHdr.SetType(header.ICMPv6NeighborSolicit)
+	copy(icmpHdr[icmpV6OptOffset-len(addr):], addr)
+	icmpHdr[icmpV6OptOffset] = ndpOptSrcLinkAddr
+	icmpHdr[icmpV6LengthOffset] = 1
+	copy(icmpHdr[icmpV6LengthOffset+1:], linkEP.LinkAddress())
+	icmpHdr.SetChecksum(header.ICMPv6Checksum(icmpHdr, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{}))
+
+	length := uint16(pkt.Size())
+	ip := header.IPv6(pkt.NetworkHeader().Push(header.IPv6MinimumSize))
 	ip.Encode(&header.IPv6Fields{
 		PayloadLength: length,
 		NextHeader:    uint8(header.ICMPv6ProtocolNumber),
@@ -559,9 +560,7 @@ func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, remoteLinkAdd
 	})
 
 	// TODO(stijlist): count this in ICMP stats.
-	return linkEP.WritePacket(r, nil /* gso */, ProtocolNumber, &stack.PacketBuffer{
-		Header: hdr,
-	})
+	return linkEP.WritePacket(r, nil /* gso */, ProtocolNumber, pkt)
 }
 
 // ResolveStaticAddress implements stack.LinkAddressResolver.
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index d7d7fc611..0ade655b2 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -99,9 +99,9 @@ func (e *endpoint) GSOMaxSize() uint32 {
 	return 0
 }
 
-func (e *endpoint) addIPHeader(r *stack.Route, hdr *buffer.Prependable, payloadSize int, params stack.NetworkHeaderParams) header.IPv6 {
-	length := uint16(hdr.UsedLength() + payloadSize)
-	ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize))
+func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams) {
+	length := uint16(pkt.Size())
+	ip := header.IPv6(pkt.NetworkHeader().Push(header.IPv6MinimumSize))
 	ip.Encode(&header.IPv6Fields{
 		PayloadLength: length,
 		NextHeader:    uint8(params.Protocol),
@@ -110,26 +110,20 @@ func (e *endpoint) addIPHeader(r *stack.Route, hdr *buffer.Prependable, payloadS
 		SrcAddr:       r.LocalAddress,
 		DstAddr:       r.RemoteAddress,
 	})
-	return ip
+	pkt.NetworkProtocolNumber = header.IPv6ProtocolNumber
 }
 
 // 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 {
-	ip := e.addIPHeader(r, &pkt.Header, pkt.Data.Size(), params)
-	pkt.NetworkHeader = buffer.View(ip)
-	pkt.NetworkProtocolNumber = header.IPv6ProtocolNumber
+	e.addIPHeader(r, pkt, params)
 
 	if r.Loop&stack.PacketLoop != 0 {
-		// The inbound path expects the network header to still be in
-		// the PacketBuffer's Data field.
-		views := make([]buffer.View, 1, 1+len(pkt.Data.Views()))
-		views[0] = pkt.Header.View()
-		views = append(views, pkt.Data.Views()...)
 		loopedR := r.MakeLoopedRoute()
 
-		e.HandlePacket(&loopedR, &stack.PacketBuffer{
-			Data: buffer.NewVectorisedView(len(views[0])+pkt.Data.Size(), views),
-		})
+		e.HandlePacket(&loopedR, stack.NewPacketBuffer(stack.PacketBufferOptions{
+			// The inbound path expects an unparsed packet.
+			Data: buffer.NewVectorisedView(pkt.Size(), pkt.Views()),
+		}))
 
 		loopedR.Release()
 	}
@@ -151,9 +145,7 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
 	}
 
 	for pb := pkts.Front(); pb != nil; pb = pb.Next() {
-		ip := e.addIPHeader(r, &pb.Header, pb.Data.Size(), params)
-		pb.NetworkHeader = buffer.View(ip)
-		pb.NetworkProtocolNumber = header.IPv6ProtocolNumber
+		e.addIPHeader(r, pb, params)
 	}
 
 	n, err := e.linkEP.WritePackets(r, gso, pkts, ProtocolNumber)
@@ -171,8 +163,8 @@ func (*endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBuff
 // HandlePacket is called by the link layer when new ipv6 packets arrive for
 // this endpoint.
 func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
-	h := header.IPv6(pkt.NetworkHeader)
-	if !h.IsValid(pkt.Data.Size() + len(pkt.NetworkHeader) + len(pkt.TransportHeader)) {
+	h := header.IPv6(pkt.NetworkHeader().View())
+	if !h.IsValid(pkt.Data.Size() + pkt.NetworkHeader().View().Size() + pkt.TransportHeader().View().Size()) {
 		r.Stats().IP.MalformedPacketsReceived.Increment()
 		return
 	}
@@ -181,8 +173,8 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
 	// - Any IPv6 header bytes after the first 40 (i.e. extensions).
 	// - The transport header, if present.
 	// - Any other payload data.
-	vv := pkt.NetworkHeader[header.IPv6MinimumSize:].ToVectorisedView()
-	vv.AppendView(pkt.TransportHeader)
+	vv := pkt.NetworkHeader().View()[header.IPv6MinimumSize:].ToVectorisedView()
+	vv.AppendView(pkt.TransportHeader().View())
 	vv.Append(pkt.Data)
 	it := header.MakeIPv6PayloadIterator(header.IPv6ExtensionHeaderIdentifier(h.NextHeader()), vv)
 	hasFragmentHeader := false
@@ -410,7 +402,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
 			//
 			// For reassembled fragments, pkt.TransportHeader is unset, so this is a
 			// no-op and pkt.Data begins with the transport header.
-			extHdr.Buf.TrimFront(len(pkt.TransportHeader))
+			extHdr.Buf.TrimFront(pkt.TransportHeader().View().Size())
 			pkt.Data = extHdr.Buf
 
 			if p := tcpip.TransportProtocolNumber(extHdr.Identifier); p == header.ICMPv6ProtocolNumber {
@@ -581,17 +573,14 @@ traverseExtensions:
 		}
 	}
 
-	// Put the IPv6 header with extensions in pkt.NetworkHeader.
-	hdr, ok = pkt.Data.PullUp(header.IPv6MinimumSize + extensionsSize)
+	// Put the IPv6 header with extensions in pkt.NetworkHeader().
+	hdr, ok = pkt.NetworkHeader().Consume(header.IPv6MinimumSize + extensionsSize)
 	if !ok {
 		panic(fmt.Sprintf("pkt.Data should have at least %d bytes, but only has %d.", header.IPv6MinimumSize+extensionsSize, pkt.Data.Size()))
 	}
 	ipHdr = header.IPv6(hdr)
-
-	pkt.NetworkProtocolNumber = header.IPv6ProtocolNumber
-	pkt.NetworkHeader = hdr
-	pkt.Data.TrimFront(len(hdr))
 	pkt.Data.CapLength(int(ipHdr.PayloadLength()))
+	pkt.NetworkProtocolNumber = header.IPv6ProtocolNumber
 
 	return nextHdr, foundNext, true
 }