northd: Use proper field for lookup_nd

We are intentionally skipping ND NA with LLA as source.
However, this doesn't work when the ND NA has LLA source,
but the target address is global one. In that case we
would skip update of already existing entry when
always_learn_from_arp_request is set to false.

Use ND target address in the check instead of source.

Fixes: 5e0cb03 ("northd: Add logical flow to skip GARP with LLA")
Reported-at: https://issues.redhat.com/browse/FDP-283
Signed-off-by: Ales Musil <amusil@redhat.com>
Acked-by: Xavier Simonart <xsimonar@redhat.com>
Signed-off-by: Dumitru Ceara <dceara@redhat.com>

northd/northd.c

@@ -13171,9 +13171,9 @@ build_neigh_learning_flows_for_lrouter(
          *   address, the all-nodes multicast address. */
         ds_clear(actions);
         ds_put_format(actions, REGBIT_LOOKUP_NEIGHBOR_RESULT
-                               " = lookup_nd(inport, ip6.src, nd.tll); "
+                               " = lookup_nd(inport, nd.target, nd.tll); "
                                REGBIT_LOOKUP_NEIGHBOR_IP_RESULT
-                               " = lookup_nd_ip(inport, ip6.src); next;");
+                               " = lookup_nd_ip(inport, nd.target); next;");
         ovn_lflow_add(lflows, od, S_ROUTER_IN_LOOKUP_NEIGHBOR, 110,
                       "nd_na && ip6.src == fe80::/10 && ip6.dst == ff00::/8",
                       ds_cstr(actions));

tests/ovn.at

@@ -5385,10 +5385,11 @@ test_arp() {
 }
 
 test_na() {
-    local inport=$1 sha=$2 spa=$3
+    local inport=$1 sha=$2 spa=$3 src=${4-$3}
     local request=$(fmt_pkt "Ether(dst='ff:ff:ff:ff:ff:ff', src='${sha}')/ \
-                             IPv6(dst='ff01::1', src='${spa}')/ \
-                             ICMPv6ND_NA(tgt='${spa}')")
+                             IPv6(dst='ff01::1', src='${src}')/ \
+                             ICMPv6ND_NA(tgt='${spa}')/ \
+                             ICMPv6NDOptDstLLAddr(lladdr='${sha}')")
 
     hv=hv`vif_to_hv $inport`
     as $hv ovs-appctl netdev-dummy/receive vif$inport $request
@@ -5464,6 +5465,24 @@ for i in 1 2; do
     done
 done
 
+# Make sure that we can update existing entry with
+# "always_learn_from_arp_request=false" even when the source of NA src is LLA.
+check ovn-sbctl --all destroy mac_binding
+check ovn-nbctl --wait=hv set logical_router lr0 options:always_learn_from_arp_request=false
+
+sha="f0:00:00:00:00:11"
+spa6="fd00::abcd:1"
+
+test_na 11 $sha $spa6
+wait_row_count MAC_Binding 1 ip=\"$spa6\" mac=\"$sha\"
+
+sha="f0:00:00:00:00:12"
+lla6="fe80::abcd:1"
+
+test_na 11 $sha $spa6 $lla6
+wait_row_count MAC_Binding 1 ip=\"$spa6\" mac=\"$sha\"
+check_row_count MAC_Binding 0 ip=\"$lla6\"
+
 # Gracefully terminate daemons
 OVN_CLEANUP([hv1], [hv2])