From 77bf586db75b3dbd9dcb14c349bde8372d26425c Mon Sep 17 00:00:00 2001 From: Ghanan Gowripalan Date: Fri, 31 Jan 2020 13:54:57 -0800 Subject: Use multicast Ethernet address for multicast NDP As per RFC 2464 section 7, an IPv6 packet with a multicast destination address is transmitted to the mapped Ethernet multicast address. Test: - ipv6.TestLinkResolution - stack_test.TestDADResolve - stack_test.TestRouterSolicitation PiperOrigin-RevId: 292610529 --- pkg/tcpip/network/ipv6/icmp.go | 6 +++++- pkg/tcpip/network/ipv6/icmp_test.go | 12 +++++++++--- 2 files changed, 14 insertions(+), 4 deletions(-) (limited to 'pkg/tcpip/network') diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index 7491cfc41..60817d36d 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -408,10 +408,14 @@ func (*protocol) LinkAddressProtocol() tcpip.NetworkProtocolNumber { // LinkAddressRequest implements stack.LinkAddressResolver. func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, linkEP stack.LinkEndpoint) *tcpip.Error { snaddr := header.SolicitedNodeAddr(addr) + + // TODO(b/148672031): Use stack.FindRoute instead of manually creating the + // route here. Note, we would need the nicID to do this properly so the right + // NIC (associated to linkEP) is used to send the NDP NS message. r := &stack.Route{ LocalAddress: localAddr, RemoteAddress: snaddr, - RemoteLinkAddress: broadcastMAC, + RemoteLinkAddress: header.EthernetAddressFromMulticastIPv6Address(snaddr), } hdr := buffer.NewPrependable(int(linkEP.MaxHeaderLength()) + header.IPv6MinimumSize + header.ICMPv6NeighborAdvertSize) pkt := header.ICMPv6(hdr.Prepend(header.ICMPv6NeighborAdvertSize)) diff --git a/pkg/tcpip/network/ipv6/icmp_test.go b/pkg/tcpip/network/ipv6/icmp_test.go index 7a6820643..d0e930e20 100644 --- a/pkg/tcpip/network/ipv6/icmp_test.go +++ b/pkg/tcpip/network/ipv6/icmp_test.go @@ -270,8 +270,9 @@ func (c *testContext) cleanup() { } type routeArgs struct { - src, dst *channel.Endpoint - typ header.ICMPv6Type + src, dst *channel.Endpoint + typ header.ICMPv6Type + remoteLinkAddr tcpip.LinkAddress } func routeICMPv6Packet(t *testing.T, args routeArgs, fn func(*testing.T, header.ICMPv6)) { @@ -292,6 +293,11 @@ func routeICMPv6Packet(t *testing.T, args routeArgs, fn func(*testing.T, header. t.Errorf("unexpected protocol number %d", pi.Proto) return } + + if len(args.remoteLinkAddr) != 0 && args.remoteLinkAddr != pi.Route.RemoteLinkAddress { + t.Errorf("got remote link address = %s, want = %s", pi.Route.RemoteLinkAddress, args.remoteLinkAddr) + } + ipv6 := header.IPv6(pi.Pkt.Header.View()) transProto := tcpip.TransportProtocolNumber(ipv6.NextHeader()) if transProto != header.ICMPv6ProtocolNumber { @@ -339,7 +345,7 @@ func TestLinkResolution(t *testing.T) { t.Fatalf("ep.Write(_) = _, , %s, want = _, , tcpip.ErrNoLinkAddress", err) } for _, args := range []routeArgs{ - {src: c.linkEP0, dst: c.linkEP1, typ: header.ICMPv6NeighborSolicit}, + {src: c.linkEP0, dst: c.linkEP1, typ: header.ICMPv6NeighborSolicit, remoteLinkAddr: header.EthernetAddressFromMulticastIPv6Address(header.SolicitedNodeAddr(lladdr1))}, {src: c.linkEP1, dst: c.linkEP0, typ: header.ICMPv6NeighborAdvert}, } { routeICMPv6Packet(t, args, func(t *testing.T, icmpv6 header.ICMPv6) { -- cgit v1.2.3