vyos.ifconfig: provide generic get_mac_synthetic() method

WireGuard, Tunnel and also PPPoE all need a ways to calculate a synthetic MAC
address used for the EUI64 link-local addresses. Instead of copying the code
from Tunnel to WireGuard to PPPoE, use a generic implementation.

1 files changed, 2 insertions, 26 deletions

diff --git a/python/vyos/ifconfig/tunnel.py b/python/vyos/ifconfig/tunnel.py
index 64c735824..5258a2cb1 100644
--- a/python/vyos/ifconfig/tunnel.py
+++ b/python/vyos/ifconfig/tunnel.py
@@ -16,10 +16,6 @@
 # https://developers.redhat.com/blog/2019/05/17/an-introduction-to-linux-virtual-interfaces-tunnels/
 # https://community.hetzner.com/tutorials/linux-setup-gre-tunnel
 
-from netaddr import EUI
-from netaddr import mac_unix_expanded
-from random import getrandbits
-
 from vyos.ifconfig.interface import Interface
 from vyos.util import dict_search
 from vyos.validate import assert_list
@@ -163,28 +159,8 @@ class TunnelIf(Interface):
         self._cmd(cmd.format(**self.config))
 
     def get_mac(self):
-        """
-        Get current interface MAC (Media Access Contrl) address used.
-
-        NOTE: Tunnel interfaces have no "MAC" address by default. The content
-              of the 'address' file in /sys/class/net/device contains the
-              local-ip thus we generate a random MAC address instead
-
-        Example:
-        >>> from vyos.ifconfig import Interface
-        >>> Interface('eth0').get_mac()
-        '00:50:ab:cd:ef:00'
-        """
-        # we choose 40 random bytes for the MAC address, this gives
-        # us e.g. EUI('00-EA-EE-D6-A3-C8') or EUI('00-41-B9-0D-F2-2A')
-        tmp = EUI(getrandbits(48)).value
-        # set locally administered bit in MAC address
-        tmp |= 0xf20000000000
-        # convert integer to "real" MAC address representation
-        mac = EUI(hex(tmp).split('x')[-1])
-        # change dialect to use : as delimiter instead of -
-        mac.dialect = mac_unix_expanded
-        return str(mac)
+        """ Get a synthetic MAC address. """
+        return self.get_mac_synthetic()
 
     def update(self, config):
         """ General helper function which works on a dictionary retrived by