From 47515f475167ffa23267ca0b9d1b39e7907587d6 Mon Sep 17 00:00:00 2001 From: Ting-Yu Wang Date: Thu, 13 Aug 2020 13:07:03 -0700 Subject: Migrate to PacketHeader API for PacketBuffer. Formerly, when a packet is constructed or parsed, all headers are set by the client code. This almost always involved prepending to pk.Header buffer or trimming pk.Data portion. This is known to prone to bugs, due to the complexity and number of the invariants assumed across netstack to maintain. In the new PacketHeader API, client will call Push()/Consume() method to construct/parse an outgoing/incoming packet. All invariants, such as slicing and trimming, are maintained by the API itself. NewPacketBuffer() is introduced to create new PacketBuffer. Zero value is no longer valid. PacketBuffer now assumes the packet is a concatenation of following portions: * LinkHeader * NetworkHeader * TransportHeader * Data Any of them could be empty, or zero-length. PiperOrigin-RevId: 326507688 --- pkg/tcpip/stack/ndp.go | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) (limited to 'pkg/tcpip/stack/ndp.go') diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go index 5174e639c..93567806b 100644 --- a/pkg/tcpip/stack/ndp.go +++ b/pkg/tcpip/stack/ndp.go @@ -746,12 +746,16 @@ func (ndp *ndpState) sendDADPacket(addr tcpip.Address, ref *referencedNetworkEnd panic(fmt.Sprintf("ndp: route resolution not immediate for route to send NDP NS for DAD (%s -> %s on NIC(%d))", header.IPv6Any, snmc, ndp.nic.ID())) } - hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + header.ICMPv6NeighborSolicitMinimumSize) - pkt := header.ICMPv6(hdr.Prepend(header.ICMPv6NeighborSolicitMinimumSize)) - pkt.SetType(header.ICMPv6NeighborSolicit) - ns := header.NDPNeighborSolicit(pkt.NDPPayload()) + icmpData := header.ICMPv6(buffer.NewView(header.ICMPv6NeighborSolicitMinimumSize)) + icmpData.SetType(header.ICMPv6NeighborSolicit) + ns := header.NDPNeighborSolicit(icmpData.NDPPayload()) ns.SetTargetAddress(addr) - pkt.SetChecksum(header.ICMPv6Checksum(pkt, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{})) + icmpData.SetChecksum(header.ICMPv6Checksum(icmpData, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{})) + + pkt := NewPacketBuffer(PacketBufferOptions{ + ReserveHeaderBytes: int(r.MaxHeaderLength()), + Data: buffer.View(icmpData).ToVectorisedView(), + }) sent := r.Stats().ICMP.V6PacketsSent if err := r.WritePacket(nil, @@ -759,7 +763,7 @@ func (ndp *ndpState) sendDADPacket(addr tcpip.Address, ref *referencedNetworkEnd Protocol: header.ICMPv6ProtocolNumber, TTL: header.NDPHopLimit, TOS: DefaultTOS, - }, &PacketBuffer{Header: hdr}, + }, pkt, ); err != nil { sent.Dropped.Increment() return err @@ -1897,12 +1901,16 @@ func (ndp *ndpState) startSolicitingRouters() { } } payloadSize := header.ICMPv6HeaderSize + header.NDPRSMinimumSize + int(optsSerializer.Length()) - hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + payloadSize) - pkt := header.ICMPv6(hdr.Prepend(payloadSize)) - pkt.SetType(header.ICMPv6RouterSolicit) - rs := header.NDPRouterSolicit(pkt.NDPPayload()) + icmpData := header.ICMPv6(buffer.NewView(payloadSize)) + icmpData.SetType(header.ICMPv6RouterSolicit) + rs := header.NDPRouterSolicit(icmpData.NDPPayload()) rs.Options().Serialize(optsSerializer) - pkt.SetChecksum(header.ICMPv6Checksum(pkt, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{})) + icmpData.SetChecksum(header.ICMPv6Checksum(icmpData, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{})) + + pkt := NewPacketBuffer(PacketBufferOptions{ + ReserveHeaderBytes: int(r.MaxHeaderLength()), + Data: buffer.View(icmpData).ToVectorisedView(), + }) sent := r.Stats().ICMP.V6PacketsSent if err := r.WritePacket(nil, @@ -1910,7 +1918,7 @@ func (ndp *ndpState) startSolicitingRouters() { Protocol: header.ICMPv6ProtocolNumber, TTL: header.NDPHopLimit, TOS: DefaultTOS, - }, &PacketBuffer{Header: hdr}, + }, pkt, ); err != nil { sent.Dropped.Increment() log.Printf("startSolicitingRouters: error writing NDP router solicit message on NIC(%d); err = %s", ndp.nic.ID(), err) -- cgit v1.2.3