vxlan: T5753: add support for VNI filtering

In a service provider network a service provider typically supports multiple
bridge domains with overlapping vlans. One bridge domain per customer. Vlans in
each bridge domain are mapped to globally unique VXLAN VNI ranges assigned to
each customer.

Without the ability of VNI filtering, we can not provide VXLAN tunnels
with multiple tenants all requiring e.g. VLAN 10.

To Test:

set interfaces vxlan vxlan987 parameters external
set interfaces vxlan vxlan987 source-interface eth0
set interfaces vxlan vxlan987 parameters vni-filter
set interfaces vxlan vxlan987 vlan-to-vni 50 vni 10050
set interfaces vxlan vxlan987 vlan-to-vni 51 vni 10051
set interfaces vxlan vxlan987 vlan-to-vni 52 vni 10052
set interfaces vxlan vxlan987 vlan-to-vni 53 vni 10053
set interfaces vxlan vxlan987 vlan-to-vni 54 vni 10054
set interfaces vxlan vxlan987 vlan-to-vni 60 vni 10060
set interfaces vxlan vxlan987 vlan-to-vni 69 vni 10069
set interfaces bridge br0 member interface vxlan987

Add new op-mode command: show bridge vni

Interface    VNI
-----------  -----------
vxlan987     10050-10054
vxlan987     10060
vxlan987     10069

(cherry picked from commit 35f6033d21053fa420e837f157cd9377a4ccd26a)

1 files changed, 6 insertions, 0 deletions

diff --git a/op-mode-definitions/show-bridge.xml.in b/op-mode-definitions/show-bridge.xml.in
index fad3f3418..5d8cc3847 100644
--- a/op-mode-definitions/show-bridge.xml.in
+++ b/op-mode-definitions/show-bridge.xml.in
@@ -21,6 +21,12 @@
               </leafNode>
             </children>
           </node>
+          <leafNode name="vni">
+            <properties>
+              <help>Virtual Network Identifier</help>
+            </properties>
+            <command>${vyos_op_scripts_dir}/bridge.py show_vni</command>
+          </leafNode>
         </children>
       </node>
       <leafNode name="bridge">