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

2 files changed, 48 insertions, 6 deletions

diff --git a/python/vyos/ifconfig/vxlan.py b/python/vyos/ifconfig/vxlan.py
index 8c5a0220e..23b6daa3a 100644
--- a/python/vyos/ifconfig/vxlan.py
+++ b/python/vyos/ifconfig/vxlan.py
@@ -22,6 +22,7 @@ from vyos.utils.assertion import assert_list
 from vyos.utils.dict import dict_search
 from vyos.utils.network import get_interface_config
 from vyos.utils.network import get_vxlan_vlan_tunnels
+from vyos.utils.network import get_vxlan_vni_filter
 
 @Interface.register
 class VXLANIf(Interface):
@@ -79,6 +80,7 @@ class VXLANIf(Interface):
             'parameters.ip.ttl'          : 'ttl',
             'parameters.ipv6.flowlabel'  : 'flowlabel',
             'parameters.nolearning'      : 'nolearning',
+            'parameters.vni_filter'      : 'vnifilter',
             'remote'                     : 'remote',
             'source_address'             : 'local',
             'source_interface'           : 'dev',
@@ -138,10 +140,14 @@ class VXLANIf(Interface):
         if not isinstance(state, bool):
             raise ValueError('Value out of range')
 
-        cur_vlan_ids = []
         if 'vlan_to_vni_removed' in self.config:
-            cur_vlan_ids = self.config['vlan_to_vni_removed']
-            for vlan in cur_vlan_ids:
+            cur_vni_filter = get_vxlan_vni_filter(self.ifname)
+            for vlan, vlan_config in self.config['vlan_to_vni_removed'].items():
+                # If VNI filtering is enabled, remove matching VNI filter
+                if dict_search('parameters.vni_filter', self.config) != None:
+                    vni = vlan_config['vni']
+                    if vni in cur_vni_filter:
+                        self._cmd(f'bridge vni delete dev {self.ifname} vni {vni}')
                 self._cmd(f'bridge vlan del dev {self.ifname} vid {vlan}')
 
         # Determine current OS Kernel vlan_tunnel setting - only adjust when needed
@@ -151,10 +157,9 @@ class VXLANIf(Interface):
         if cur_state != new_state:
             self.set_interface('vlan_tunnel', new_state)
 
-        # Determine current OS Kernel configured VLANs
-        os_configured_vlan_ids = get_vxlan_vlan_tunnels(self.ifname)
-
         if 'vlan_to_vni' in self.config:
+            # Determine current OS Kernel configured VLANs
+            os_configured_vlan_ids = get_vxlan_vlan_tunnels(self.ifname)
             add_vlan = list_diff(list(self.config['vlan_to_vni'].keys()), os_configured_vlan_ids)
 
             for vlan, vlan_config in self.config['vlan_to_vni'].items():
@@ -168,6 +173,10 @@ class VXLANIf(Interface):
                 self._cmd(f'bridge vlan add dev {self.ifname} vid {vlan}')
                 self._cmd(f'bridge vlan add dev {self.ifname} vid {vlan} tunnel_info id {vni}')
 
+                # If VNI filtering is enabled, install matching VNI filter
+                if dict_search('parameters.vni_filter', self.config) != None:
+                    self._cmd(f'bridge vni add dev {self.ifname} vni {vni}')
+
     def update(self, config):
         """ General helper function which works on a dictionary retrived by
         get_config_dict(). It's main intention is to consolidate the scattered
diff --git a/python/vyos/utils/network.py b/python/vyos/utils/network.py
index 5d19f256b..6a5de5423 100644
--- a/python/vyos/utils/network.py
+++ b/python/vyos/utils/network.py
@@ -483,3 +483,36 @@ def get_vxlan_vlan_tunnels(interface: str) -> list:
             os_configured_vlan_ids.append(str(vlanStart))
 
     return os_configured_vlan_ids
+
+def get_vxlan_vni_filter(interface: str) -> list:
+    """ Return a list of strings with VNIs configured in the Kernel"""
+    from json import loads
+    from vyos.utils.process import cmd
+
+    if not interface.startswith('vxlan'):
+        raise ValueError('Only applicable for VXLAN interfaces!')
+
+    # Determine current OS Kernel configured VNI filters in VXLAN interface
+    #
+    # $ bridge -j vni show dev vxlan1
+    # [{"ifname":"vxlan1","vnis":[{"vni":100},{"vni":200},{"vni":300,"vniEnd":399}]}]
+    #
+    # Example output: ['10010', '10020', '10021', '10022']
+    os_configured_vnis = []
+    tmp = loads(cmd(f'bridge --json vni show dev {interface}'))
+    if tmp:
+        for tunnel in tmp[0].get('vnis', {}):
+            vniStart = tunnel['vni']
+            if 'vniEnd' in tunnel:
+                vniEnd = tunnel['vniEnd']
+                # Build a real list for user VNIs
+                vni_list = list(range(vniStart, vniEnd +1))
+                # Convert list of integers to list or strings
+                os_configured_vnis.extend(map(str, vni_list))
+                # Proceed with next tunnel - this one is complete
+                continue
+
+            # Add single tunel id - not part of a range
+            os_configured_vnis.append(str(vniStart))
+
+    return os_configured_vnis