[ovs-dev,branch-21.06] Disable ARP/NA responders for vlan-passthru switches

When vlan-passthru is on, VIFs may attach different VLAN tags. In this
case, VIFs are not guaranteed to belong to the same L2 broadcast domain.
Because of that, we don't know if a peer port on the switch has the same
tag used and should not allow the local responder to generate neighbour
traffic. Instead, pass ARP and ND requests to the peer port owner and
allow it to reply, if needed.

Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: Numan Siddique <numans@ovn.org>
(cherry picked from commit ea57f666f6eef1eb1d578f0e975baa14c5d23ec9)
---
 northd/ovn-northd.8.xml |   6 ++-
 northd/ovn-northd.c     |   4 ++
 northd/ovn_northd.dl    |   6 ++-
 tests/ovn.at            | 112 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 124 insertions(+), 4 deletions(-)

Bleep bloop.  Greetings Ihar Hrachyshka, I am a robot and I have tried out your patch.
Thanks for your contribution.

I encountered some error that I wasn't expecting.  See the details below.


checkpatch:
WARNING: Unexpected sign-offs from developers who are not authors or co-authors or committers: Numan Siddique <numans@ovn.org>
Lines checked: 204, Warnings: 1, Errors: 0


Please check this out.  If you feel there has been an error, please email aconole@redhat.com

Thanks,
0-day Robot

I pushed this to branch-21.06.

On 6/29/21 12:20 PM, Ihar Hrachyshka wrote:
> When vlan-passthru is on, VIFs may attach different VLAN tags. In this
> case, VIFs are not guaranteed to belong to the same L2 broadcast domain.
> Because of that, we don't know if a peer port on the switch has the same
> tag used and should not allow the local responder to generate neighbour
> traffic. Instead, pass ARP and ND requests to the peer port owner and
> allow it to reply, if needed.
> 
> Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
> Signed-off-by: Numan Siddique <numans@ovn.org>
> (cherry picked from commit ea57f666f6eef1eb1d578f0e975baa14c5d23ec9)
> ---
>   northd/ovn-northd.8.xml |   6 ++-
>   northd/ovn-northd.c     |   4 ++
>   northd/ovn_northd.dl    |   6 ++-
>   tests/ovn.at            | 112 ++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 124 insertions(+), 4 deletions(-)
> 
> diff --git a/northd/ovn-northd.8.xml b/northd/ovn-northd.8.xml
> index 407464602..21ae0ca60 100644
> --- a/northd/ovn-northd.8.xml
> +++ b/northd/ovn-northd.8.xml
> @@ -1072,8 +1072,10 @@ output;
>             <code>localport</code> ports) that are down (unless <code>
>             ignore_lsp_down</code> is configured as true in <code>options</code>
>             column of <code>NB_Global</code> table of the <code>Northbound</code>
> -          database), for logical ports of type <code>virtual</code> and for
> -          logical ports with 'unknown' address set.
> +          database), for logical ports of type <code>virtual</code>, for
> +          logical ports with 'unknown' address set and for logical ports of
> +          a logical switch configured with
> +          <code>other_config:vlan-passthru=true</code>.
>           </p>
>         </li>
>   
> diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
> index 3dae7bb1c..17bcede5a 100644
> --- a/northd/ovn-northd.c
> +++ b/northd/ovn-northd.c
> @@ -7007,6 +7007,10 @@ build_lswitch_arp_nd_responder_known_ips(struct ovn_port *op,
>                   return;
>               }
>   
> +            if (is_vlan_transparent(op->od)) {
> +                return;
> +            }
> +
>               for (size_t i = 0; i < op->n_lsp_addrs; i++) {
>                   for (size_t j = 0; j < op->lsp_addrs[i].n_ipv4_addrs; j++) {
>                       ds_clear(match);
> diff --git a/northd/ovn_northd.dl b/northd/ovn_northd.dl
> index 3afa80a3b..a09aea6ee 100644
> --- a/northd/ovn_northd.dl
> +++ b/northd/ovn_northd.dl
> @@ -3309,7 +3309,8 @@ for (CheckLspIsUp[check_lsp_is_up]) {
>               ((lsp_is_up(lsp) or not check_lsp_is_up)
>                or lsp.__type == "router" or lsp.__type == "localport") and
>               lsp.__type != "external" and lsp.__type != "virtual" and
> -            not lsp.addresses.contains("unknown"))
> +            not lsp.addresses.contains("unknown") and
> +            not sw.is_vlan_transparent)
>       {
>           var __match = "arp.tpa == ${addr.addr} && arp.op == 1" in
>           {
> @@ -3359,7 +3360,8 @@ for (SwitchPortIPv6Address(.port = &SwitchPort{.lsp = lsp, .json_name = json_nam
>                              .ea = ea, .addr = addr)
>        if lsp.is_enabled() and
>           (lsp_is_up(lsp) or lsp.__type == "router" or lsp.__type == "localport") and
> -        lsp.__type != "external" and lsp.__type != "virtual")
> +        lsp.__type != "external" and lsp.__type != "virtual" and
> +        not sw.is_vlan_transparent)
>   {
>       var __match = "nd_ns && ip6.dst == {${addr.addr}, ${addr.solicited_node()}} && nd.target == ${addr.addr}" in
>       var actions = "${if (lsp.__type == \"router\") \"nd_na_router\" else \"nd_na\"} { "
> diff --git a/tests/ovn.at b/tests/ovn.at
> index b6523c328..811a05c5a 100644
> --- a/tests/ovn.at
> +++ b/tests/ovn.at
> @@ -3169,6 +3169,118 @@ OVN_CLEANUP([hv-1],[hv-2])
>   AT_CLEANUP
>   ])
>   
> +OVN_FOR_EACH_NORTHD([
> +AT_SETUP([ovn -- VLAN transparency, passthru=true, ARP responder disabled])
> +ovn_start
> +
> +net_add net
> +check ovs-vsctl add-br br-phys
> +ovn_attach net br-phys 192.168.0.1
> +
> +check ovn-nbctl ls-add ls
> +check ovn-nbctl --wait=sb add Logical-Switch ls other_config vlan-passthru=true
> +
> +for i in 1 2; do
> +    check ovn-nbctl lsp-add ls lsp$i
> +    check ovn-nbctl lsp-set-addresses lsp$i "f0:00:00:00:00:0$i 10.0.0.$i"
> +done
> +
> +for i in 1 2; do
> +    check ovs-vsctl add-port br-int vif$i -- set Interface vif$i external-ids:iface-id=lsp$i \
> +                                  options:tx_pcap=vif$i-tx.pcap \
> +                                  options:rxq_pcap=vif$i-rx.pcap \
> +                                  ofport-request=$i
> +done
> +
> +wait_for_ports_up
> +
> +ovn-sbctl dump-flows ls > lsflows
> +AT_CAPTURE_FILE([lsflows])
> +
> +AT_CHECK([grep -w "ls_in_arp_rsp" lsflows | sort], [0], [dnl
> +  table=16(ls_in_arp_rsp      ), priority=0    , match=(1), action=(next;)
> +])
> +
> +test_arp() {
> +    local inport=$1 outport=$2 sha=$3 spa=$4 tpa=$5 reply_ha=$6
> +    tag=8100fefe
> +    local request=ffffffffffff${sha}${tag}08060001080006040001${sha}${spa}ffffffffffff${tpa}
> +    ovs-appctl netdev-dummy/receive vif$inport $request
> +    echo $request >> $outport.expected
> +
> +    local reply=${sha}${reply_ha}${tag}08060001080006040002${reply_ha}${tpa}${sha}${spa}
> +    ovs-appctl netdev-dummy/receive vif$outport $reply
> +    echo $reply >> $inport.expected
> +}
> +
> +test_arp 1 2 f00000000001 0a000001 0a000002 f00000000002
> +test_arp 2 1 f00000000002 0a000002 0a000001 f00000000001
> +
> +for i in 1 2; do
> +    OVN_CHECK_PACKETS([vif$i-tx.pcap], [$i.expected])
> +done
> +
> +AT_CLEANUP
> +])
> +
> +OVN_FOR_EACH_NORTHD([
> +AT_SETUP([ovn -- VLAN transparency, passthru=true, ND/NA responder disabled])
> +ovn_start
> +
> +net_add net
> +check ovs-vsctl add-br br-phys
> +ovn_attach net br-phys 192.168.0.1
> +
> +check ovn-nbctl ls-add ls
> +check ovn-nbctl --wait=sb add Logical-Switch ls other_config vlan-passthru=true
> +
> +for i in 1 2; do
> +    check ovn-nbctl lsp-add ls lsp$i
> +    check ovn-nbctl lsp-set-addresses lsp$i "f0:00:00:00:00:0$i fe00::$i"
> +done
> +
> +for i in 1 2; do
> +    check ovs-vsctl add-port br-int vif$i -- set Interface vif$i external-ids:iface-id=lsp$i \
> +                                  options:tx_pcap=vif$i-tx.pcap \
> +                                  options:rxq_pcap=vif$i-rx.pcap \
> +                                  ofport-request=$i
> +done
> +
> +wait_for_ports_up
> +
> +ovn-sbctl dump-flows ls > lsflows
> +AT_CAPTURE_FILE([lsflows])
> +
> +AT_CHECK([grep -w "ls_in_arp_rsp" lsflows | sort], [0], [dnl
> +  table=16(ls_in_arp_rsp      ), priority=0    , match=(1), action=(next;)
> +])
> +
> +test_nd_na() {
> +    local inport=$1 outport=$2 sha=$3 spa=$4 tpa=$5 reply_ha=$6
> +    tag=8100fefe
> +    icmp_type=87
> +    local request=ffffffffffff${sha}${tag}86dd6000000000183aff${spa}ff0200000000000000000001ff${tpa: -6}${icmp_type}007ea100000000${tpa}
> +    ovs-appctl netdev-dummy/receive vif$inport $request
> +    echo $request >> $outport.expected
> +    echo $request
> +
> +    icmp_type=88
> +    local reply=${sha}${reply_ha}${tag}86dd6000000000183aff${tpa}${spa}${icmp_type}003da540000000${tpa}
> +    ovs-appctl netdev-dummy/receive vif$outport $reply
> +    echo $reply >> $inport.expected
> +    echo $reply
> +}
> +
> +test_nd_na 1 2 f00000000001 fe000000000000000000000000000001 fe000000000000000000000000000002 f00000000002
> +test_nd_na 2 1 f00000000002 fe000000000000000000000000000002 fe000000000000000000000000000001 f00000000001
> +
> +for i in 1 2; do
> +    OVN_CHECK_PACKETS([vif$i-tx.pcap], [$i.expected])
> +done
> +
> +AT_CLEANUP
> +])
> +
>   OVN_FOR_EACH_NORTHD([
>   AT_SETUP([ovn -- VLAN transparency, passthru=true, multiple hosts])
>   ovn_start
>