T3068: Automatic generation of IPv6 link local addresses for tunnel interfaces

Tunnel interfaces hot having any IPv6 Link Local address because Linux Kernel does not assign address due to missing MAC. I have implemented a function to generate a linl local address and assign it to the interface. Link local address is required  for OSPF and other protocols.

1 files changed, 14 insertions, 0 deletions

diff --git a/python/vyos/ifconfig/tunnel.py b/python/vyos/ifconfig/tunnel.py
index 4122d1a2f..0c87ce3c5 100644
--- a/python/vyos/ifconfig/tunnel.py
+++ b/python/vyos/ifconfig/tunnel.py
@@ -22,6 +22,10 @@ from vyos.ifconfig.interface import Interface
 from vyos.ifconfig.afi import IP4, IP6
 from vyos.validate import assert_list
 
+import random
+from random import seed, getrandbits
+from ipaddress import IPv6Network, IPv6Address
+
 def enable_to_on(value):
     if value == 'enable':
         return 'on'
@@ -98,6 +102,16 @@ class _Tunnel(Interface):
                             for k in self.options if k in self.config and self.config[k]])
         self._cmd('{} {}'.format(self.create.format(**self.config), options))
         self.set_admin_state('down')
+        
+        # Linux Kernel does not generate IPv6 Link Local address do to missing MAC
+        # We have to generate address manually and assign to interface
+        net = IPv6Network("FE80::/16")
+        rand_net = IPv6Network((net.network_address + (random.getrandbits(64 - net.prefixlen) << 64 ),64))
+        network = IPv6Network(rand_net)
+        address = str(IPv6Address(network.network_address + getrandbits(network.max_prefixlen - network.prefixlen)))+'/'+str(network.prefixlen)
+        
+        # Assign generated IPv6 Link Local address to the interface
+        self.add_addr(address)
 
     def _delete(self):
         self.set_admin_state('down')