On Wed, Jun 7, 2023 at 4:48 PM Dumitru Ceara <[email protected]> wrote:
> On 6/7/23 14:41, Ihar Hrachyshka wrote: > > Thank you Ales! > > > > Acked-By: Ihar Hrachyshka <[email protected]> > > > > Hi Ales, Ihar, > Hi Dumitru, > > > On Wed, Jun 7, 2023 at 1:58 AM Ales Musil <[email protected]> wrote: > > > >> Skip GARP packet with link-local address being advertised > >> when "always_learn_from_arp_request=false", this should > >> prevent huge grow of MAC Binding table. To keep the option > >> consistent overwrite the previous MAC with LLA if it was > >> already stored in DB. > >> > >> Reported-at: https://bugzilla.redhat.com/2211240 > >> Signed-off-by: Ales Musil <[email protected]> > >> --- > >> v2: Remove leftover from previous tests. > >> v3: Address comments from Ihar: > >> - Move the condition next to the other "nd_na" flow. > >> - Update the comment for the flow. > >> --- > >> northd/northd.c | 11 +++++++ > >> tests/ovn.at | 78 ++++++++++++++++++++++++++++++++----------------- > > We miss an update of ovn-northd.8.xml. > > >> 2 files changed, 63 insertions(+), 26 deletions(-) > >> > >> diff --git a/northd/northd.c b/northd/northd.c > >> index 93f126aa3..e7a434243 100644 > >> --- a/northd/northd.c > >> +++ b/northd/northd.c > >> @@ -11942,6 +11942,17 @@ build_neigh_learning_flows_for_lrouter( > >> ovn_lflow_add(lflows, od, S_ROUTER_IN_LOOKUP_NEIGHBOR, 100, > "nd_na", > >> ds_cstr(actions)); > >> > >> + if (!learn_from_arp_request) { > >> + /* Add flow to skip LLA if we don't know it already. */ > >> + ds_clear(actions); > >> + ds_put_format(actions, REGBIT_LOOKUP_NEIGHBOR_RESULT > >> + " = lookup_nd(inport, ip6.src, nd.tll); > " > >> + REGBIT_LOOKUP_NEIGHBOR_IP_RESULT > >> + " = lookup_nd_ip(inport, ip6.src); > next;"); > >> + ovn_lflow_add(lflows, od, S_ROUTER_IN_LOOKUP_NEIGHBOR, 110, > >> + "nd_na && ip6.src == fe80::/10", > ds_cstr(actions)); > >> + } > >> + > > This doesn't match the commit message; we do more than "skipping GARP". > We actually stop learning from all neighbor advertisements that use LLA. > In theory that makes sense but today OVN actually needs to "learn" the > mac-binding even if it's for a link local address. > > With your patch, with learn_from_arp_request == false, we break all > traffic with destination IP == "LLA owned by a logical router". That's > because the logical router will send a NS for the source IP and then > will just ignore the corresponding NA reply. Maybe we should just find > a way to statically determine the MAC address from the destination LLA. > > What do you think? > You are right, what about restricting the match further to "ip6.dst == ff00::/8" as per RFC 2461: Destination Address For solicited advertisements, the Source Address of an invoking Neighbor Solicitation or, if the solicitation's Source Address is the unspecified address, the all-nodes multicast address. For unsolicited advertisements typically the all- nodes multicast address. The suggestion to extract the MAC would be probably harder to pull off. Thanks, Ales > Regards, > Dumitru > > >> ds_clear(actions); > >> ds_put_format(actions, REGBIT_LOOKUP_NEIGHBOR_RESULT > >> " = lookup_nd(inport, ip6.src, nd.sll); %snext;", > >> diff --git a/tests/ovn.at b/tests/ovn.at > >> index 5e6a8fefa..7cb1f8a95 100644 > >> --- a/tests/ovn.at > >> +++ b/tests/ovn.at > >> @@ -5062,6 +5062,7 @@ AT_CLEANUP > >> > >> OVN_FOR_EACH_NORTHD([ > >> AT_SETUP([IP relocation using GARP request]) > >> +AT_SKIP_IF([test $HAVE_SCAPY = no]) > >> ovn_start > >> > >> # Logical network: > >> @@ -5161,7 +5162,9 @@ done > >> test_ip() { > >> # This packet has bad checksums but logical L3 routing doesn't > check. > >> local inport=$1 src_mac=$2 dst_mac=$3 src_ip=$4 dst_ip=$5 > >> - local > >> > packet=${dst_mac}${src_mac}08004500001c0000000040110000${src_ip}${dst_ip}0035111100080000 > >> + local packet=$(fmt_pkt "Ether(dst='${dst_mac}', src='${src_mac}')/ > \ > >> + IP(dst='${dst_ip}', src='${src_ip}')/ \ > >> + UDP(sport=53, dport=4369)") > >> shift; shift; shift; shift; shift > >> hv=hv`vif_to_hv $inport` > >> as $hv ovs-appctl netdev-dummy/receive vif$inport $packet > >> @@ -5176,7 +5179,9 @@ test_ip() { > >> # Routing decrements TTL and updates source and dest MAC > >> # (and checksum). > >> out_lrp=`vif_to_lrp $outport` > >> - echo > >> > f000000000${outport}00000000ff0${out_lrp}08004500001c00000000"3f1101"00${src_ip}${dst_ip}0035111100080000 > >> + echo $(fmt_pkt "Ether(dst='f0:00:00:00:00:${outport}', > >> src='00:00:00:00:ff:${out_lrp}')/ \ > >> + IP(src='${src_ip}', dst='${dst_ip}', > ttl=63)/ > >> \ > >> + UDP(sport=53, dport=4369)") > >> fi >> $outport.expected > >> done > >> } > >> @@ -5192,8 +5197,10 @@ test_ip() { > >> # SHA and REPLY_HA are each 12 hex digits. > >> # SPA and TPA are each 8 hex digits. > >> test_arp() { > >> - local inport=$1 sha=$2 spa=$3 tpa=$4 reply_ha=$5 > >> - local > >> > request=ffffffffffff${sha}08060001080006040001${sha}${spa}ffffffffffff${tpa} > >> + local inport=$1 sha=$2 spa=$3 tpa=$3 > >> + local request=$(fmt_pkt "Ether(dst='ff:ff:ff:ff:ff:ff', > >> src='${sha}')/ \ > >> + ARP(hwsrc='${sha}', > >> hwdst='ff:ff:ff:ff:ff:ff', psrc='${spa}', pdst='${tpa}')") > >> + > >> hv=hv`vif_to_hv $inport` > >> as $hv ovs-appctl netdev-dummy/receive vif$inport $request > >> > >> @@ -5206,53 +5213,72 @@ test_arp() { > >> echo $request >> $i$j$k.expected > >> fi > >> done > >> +} > >> > >> - # Expect to receive the reply, if any. > >> - if test X$reply_ha != X; then > >> - lrp=`vif_to_lrp $inport` > >> - local > >> > reply=${sha}00000000ff0${lrp}08060001080006040002${reply_ha}${tpa}${sha}${spa} > >> - echo $reply >> $inport.expected > >> - fi > >> +test_na() { > >> + local inport=$1 sha=$2 spa=$3 > >> + local request=$(fmt_pkt "Ether(dst='ff:ff:ff:ff:ff:ff', > >> src='${sha}')/ \ > >> + IPv6(dst='fe80::1', src='${spa}')/ \ > >> + ICMPv6ND_NA(tgt='${spa}')") > >> + > >> + hv=hv`vif_to_hv $inport` > >> + as $hv ovs-appctl netdev-dummy/receive vif$inport $request > >> + > >> + # Expect to receive the broadcast ARP on the other logical switch > >> ports if > >> + # IP address is not configured to the switch patch port. > >> + local i=`vif_to_ls $inport` > >> + local j > >> + for j in 1 2; do > >> + if test $i$j != $inport; then > >> + echo $request >> $i$j$k.expected > >> + fi > >> + done > >> } > >> > >> -# lp11 send GARP request to announce ownership of 192.168.1.100. > >> +# lp11 send GARP request to announce ownership of 192.168.1.100 and > >> fe80::abcd:1. > >> > >> -sha=f00000000011 > >> -spa=`ip_to_hex 192 168 1 100` > >> -tpa=$spa > >> +sha="f0:00:00:00:00:11" > >> +spa="192.168.1.100" > >> +spa6="fe80::abcd:1" > >> > >> # When always_learn_from_arp_request=false, the new mac-binding will > not > >> be learned > >> # through GARP request. > >> ovn-nbctl --wait=hv set logical_router lr0 > >> options:always_learn_from_arp_request=false > >> > >> -test_arp 11 $sha $spa $tpa > >> +test_arp 11 $sha $spa > >> +test_na 11 $sha $spa6 > >> sleep 1 > >> -check_row_count MAC_Binding 0 ip="192.168.1.100" > >> +check_row_count MAC_Binding 0 ip="$spa" > >> +check_row_count MAC_Binding 0 ip="$spa6" > >> > >> # When always_learn_from_arp_request=true, the new mac-binding will be > >> learned. > >> ovn-nbctl --wait=hv set logical_router lr0 > >> options:always_learn_from_arp_request=true > >> > >> -test_arp 11 $sha $spa $tpa > >> -OVS_WAIT_UNTIL([test `ovn-sbctl find mac_binding ip="192.168.1.100" | > wc > >> -l` -gt 0]) > >> +test_arp 11 $sha $spa > >> +test_na 11 $sha $spa6 > >> +wait_row_count MAC_Binding 1 ip="$spa" mac=\"$sha\" > >> +wait_row_count MAC_Binding 1 ip=\"$spa6\" mac=\"$sha\" > >> ovn-nbctl --wait=hv sync > >> > >> # Send an IP packet from lp21 to 192.168.1.100, which should go to > lp11. > >> > >> -smac=f00000000021 > >> -dmac=00000000ff02 > >> -sip=`ip_to_hex 192 168 2 11` > >> -dip=`ip_to_hex 192 168 1 100` > >> +smac="f0:00:00:00:00:21" > >> +dmac="00:00:00:00:ff:02" > >> +sip="192.168.2.11" > >> +dip="192.168.1.100" > >> test_ip 21 $smac $dmac $sip $dip 11 > >> > >> -# lp12 send GARP request to announce ownership of 192.168.1.100. > >> +# lp12 send GARP request to announce ownership of 192.168.1.100 and > >> fe80::abcd:1. > >> > >> # Even when always_learn_from_arp_request=false, the existing > mac-binding > >> should be > >> # updated through GARP request. > >> ovn-nbctl --wait=hv set logical_router lr0 > >> options:always_learn_from_arp_request=false > >> > >> -sha=f00000000012 > >> -test_arp 12 $sha $spa $tpa > >> -wait_row_count MAC_Binding 1 ip="192.168.1.100" > mac='"f0:00:00:00:00:12"' > >> +sha="f0:00:00:00:00:12" > >> +test_arp 12 $sha $spa > >> +test_na 11 $sha $spa6 > >> +wait_row_count MAC_Binding 1 ip="$spa" mac=\"$sha\" > >> +wait_row_count MAC_Binding 1 ip=\"$spa6\" mac=\"$sha\" > >> ovn-nbctl --wait=hv sync > >> # give to the hv the time to send queued ip packets > >> sleep 1 > >> -- > >> 2.40.1 > >> > >> _______________________________________________ > >> dev mailing list > >> [email protected] > >> https://mail.openvswitch.org/mailman/listinfo/ovs-dev > >> > >> > > _______________________________________________ > > dev mailing list > > [email protected] > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > -- Ales Musil Senior Software Engineer - OVN Core Red Hat EMEA <https://www.redhat.com> [email protected] IM: amusil <https://red.ht/sig> _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
