Support 802.11ad EthType for localnet ports

In some environments, hardware serving the fabric network doesn't
support double 802.1q (0x8100) VLAN tags, but does support 802.11ad
(0x8a88) EthType for two layer VLAN traffic. Specifically, Cisco
hardware UCS VIC was identified affected by this limitation.

With vlan-passthru=true set for a logical switch, VLAN tagged traffic
may be generated by VIFs. This patch allows to support the feature in
affected hardware environments.

Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: Numan Siddique <numans@ovn.org>

NEWS

@@ -10,6 +10,7 @@ Post-v21.03.0
   - Introduced parallel processing in ovn-northd with the NB_Global config option
     'use_parallel_build' to enable it.  It is disabled by default.
   - Support vlan-passthru mode for tag=0 localnet ports.
+  - Support custom 802.11ad EthType for localnet ports.
 
 OVN v21.03.0 - 12 Mar 2021
 -------------------------

controller/physical.c

@@ -609,6 +609,34 @@ put_replace_chassis_mac_flows(const struct simap *ct_zones,
     }
 }
 
+#define VLAN_80211AD_ETHTYPE 0x88a8
+#define VLAN_80211Q_ETHTYPE 0x8100
+
+static void
+ofpact_put_push_vlan(struct ofpbuf *ofpacts, const struct smap *options, int tag)
+{
+    const char *ethtype_opt = options ? smap_get(options, "ethtype") : NULL;
+
+    int ethtype = VLAN_80211Q_ETHTYPE;
+    if (ethtype_opt) {
+        if (!strcasecmp(ethtype_opt, "802.11ad")) {
+            ethtype = VLAN_80211AD_ETHTYPE;
+        } else if (strcasecmp(ethtype_opt, "802.11q")) {
+            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
+            VLOG_WARN_RL(&rl, "Unknown port ethtype: %s", ethtype_opt);
+        }
+    }
+
+    struct ofpact_push_vlan *push_vlan;
+    push_vlan = ofpact_put_PUSH_VLAN(ofpacts);
+    push_vlan->ethertype = htons(ethtype);
+
+    struct ofpact_vlan_vid *vlan_vid;
+    vlan_vid = ofpact_put_SET_VLAN_VID(ofpacts);
+    vlan_vid->vlan_vid = tag;
+    vlan_vid->push_vlan_if_needed = false;
+}
+
 static void
 put_replace_router_port_mac_flows(struct ovsdb_idl_index
                                   *sbrec_port_binding_by_name,
@@ -696,10 +724,7 @@ put_replace_router_port_mac_flows(struct ovsdb_idl_index
         replace_mac->mac = chassis_mac;
 
         if (tag) {
-            struct ofpact_vlan_vid *vlan_vid;
-            vlan_vid = ofpact_put_SET_VLAN_VID(ofpacts_p);
-            vlan_vid->vlan_vid = tag;
-            vlan_vid->push_vlan_if_needed = true;
+            ofpact_put_push_vlan(ofpacts_p, &localnet_port->options, tag);
         }
 
         ofpact_put_OUTPUT(ofpacts_p)->port = ofport;
@@ -1203,10 +1228,9 @@ consider_port_binding(struct ovsdb_idl_index *sbrec_port_binding_by_name,
         if (tag) {
             /* For containers sitting behind a local vif, tag the packets
              * before delivering them. */
-            struct ofpact_vlan_vid *vlan_vid;
-            vlan_vid = ofpact_put_SET_VLAN_VID(ofpacts_p);
-            vlan_vid->vlan_vid = tag;
-            vlan_vid->push_vlan_if_needed = true;
+            ofpact_put_push_vlan(
+                ofpacts_p, localnet_port ? &localnet_port->options : NULL,
+                tag);
         }
         ofpact_put_OUTPUT(ofpacts_p)->port = ofport;
         if (tag) {

ovn-nb.xml

@@ -847,6 +847,12 @@
           uses its local configuration to determine exactly how to connect to
           this locally accessible network, if at all.
         </column>
+
+        <column name="options" key="ethtype">
+          Optional. VLAN EtherType field value for encapsulating VLAN
+          headers. Supported values: 802.11q (default), 802.11ad.
+        </column>
+
       </group>
 
       <group title="Options for l2gateway ports">

tests/ovn.at

@@ -3227,6 +3227,91 @@ done
 AT_CLEANUP
 ])
 
+OVN_FOR_EACH_NORTHD([
+AT_SETUP([ovn -- VLAN transparency, passthru=true, multiple hosts, custom ethtype])
+ovn_start
+
+ethtype=802.11ad
+
+check ovn-nbctl ls-add ls
+check ovn-nbctl --wait=sb add Logical-Switch ls other_config vlan-passthru=true
+
+ln_port_name=ln-100
+ovn-nbctl lsp-add ls $ln_port_name "" 100
+ovn-nbctl lsp-set-addresses $ln_port_name unknown
+ovn-nbctl lsp-set-type $ln_port_name localnet
+ovn-nbctl lsp-set-options $ln_port_name network_name=phys-100 ethtype=$ethtype
+net_add n-100
+
+# two hypervisors, each connected to the same network
+for i in 1 2; do
+    sim_add hv-$i
+    as hv-$i
+    ovs-vsctl add-br br-phys
+    ovs-vsctl set open . external-ids:ovn-bridge-mappings=phys-100:br-phys
+    ovn_attach n-100 br-phys 192.168.0.$i
+done
+
+for i in 1 2; do
+    check ovn-nbctl lsp-add ls lsp$i
+    check ovn-nbctl lsp-set-addresses lsp$i f0:00:00:00:00:0$i
+done
+
+for i in 1 2; do
+    as hv-$i
+    check ovs-vsctl add-port br-int vif$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=$i
+    wait_for_ports_up lsp$i
+done
+
+# create taps on fabric to check vlan encapsulation there
+for i in 1 2; do
+    as hv-$i
+    ovs-vsctl add-port br-phys tap$i -- set Interface tap$i \
+                                  options:tx_pcap=tap$i-tx.pcap \
+                                  options:rxq_pcap=tap$i-rx.pcap
+done
+
+for i in 1 2; do
+    : > $i.expected
+done
+: > tap.expected
+
+test_packet() {
+    local inport=$1 dst=$2 src=$3 eth=$4 lout=$5 ethtype=$6
+
+    # First try tracing the packet.
+    uflow="inport==\"lsp$inport\" && eth.dst==$dst && eth.src==$src && eth.type==0x$eth && vlan.present==1"
+    echo "output(\"$lout\");" > expout
+    AT_CAPTURE_FILE([trace])
+    AT_CHECK([ovn-trace --all ls "$uflow" | tee trace | sed '1,/Minimal trace/d'], [0], [expout])
+
+    # Then actually send a packet, for an end-to-end test.
+    payload=fefefefe
+    local packet=$(echo $dst$src | sed 's/://g')${eth}${payload}
+    vif=vif$inport
+    as hv-$1
+    ovs-appctl netdev-dummy/receive $vif $packet
+    echo $packet >> ${inport}.expected
+
+    phys_packet=$(echo $dst$src | sed 's/://g')${ethtype}0064${eth}${payload}
+    echo $phys_packet >> tap.expected
+}
+
+test_packet 1 f0:00:00:00:00:03 f0:00:00:00:00:01 8100 ln-100 88a8
+test_packet 2 f0:00:00:00:00:03 f0:00:00:00:00:02 8100 ln-100 88a8
+for i in 1 2; do
+    OVN_CHECK_PACKETS_REMOVE_BROADCAST([vif$i-rx.pcap], [$i.expected])
+done
+for i in 1 2; do
+    OVN_CHECK_PACKETS_REMOVE_BROADCAST([tap$i-tx.pcap], [tap.expected])
+done
+
+AT_CLEANUP
+])
+
 OVN_FOR_EACH_NORTHD([
 AT_SETUP([ovn -- VLAN transparency, passthru=true, multiple hosts, flat/untagged])
 ovn_start