ethernet: T8084: prevent MAC changes on ENA interfaces (AWS EC2)

Add a safeguard to block MAC address changes when the underlying driver is ENA
(used on AWS EC2), and display a clear error message instead of raising
"OSError: [Errno 95] Operation not supported."

2 files changed, 23 insertions, 0 deletions

diff --git a/python/vyos/ethtool.py b/python/vyos/ethtool.py
index 22e066def..76c5b29f0 100644
--- a/python/vyos/ethtool.py
+++ b/python/vyos/ethtool.py
@@ -25,6 +25,10 @@ _drivers_without_speed_duplex_flow = ['vmxnet3', 'virtio_net', 'xen_netfront',
                                       'iavf', 'ice', 'i40e', 'hv_netvsc', 'veth', 'ixgbevf',
                                       'tun', 'vif']
 
+_drivers_without_mac_change = ['ena']
+# enable interface bonding will change the interface MAC address, thus all drivers
+# not supporting MAC address change, also do not support bonding
+
 class Ethtool:
     """
     Class is used to retrive and cache information about an ethernet adapter
@@ -222,3 +226,7 @@ class Ethtool:
         matches = re.findall(rf'{rx_tx_comb}:\s+(\d+)', self._channels)
 
         return [int(value) for value in matches]
+
+    def check_mac_change(self) -> bool:
+        """ Check if ethernet drivers supports changing MAC address """
+        return bool(self.get_driver_name() not in _drivers_without_mac_change)
diff --git a/src/conf_mode/interfaces_ethernet.py b/src/conf_mode/interfaces_ethernet.py
index 8e490884f..d926c458c 100755
--- a/src/conf_mode/interfaces_ethernet.py
+++ b/src/conf_mode/interfaces_ethernet.py
@@ -273,6 +273,20 @@ def verify_offload(ethernet: dict, ethtool: Ethtool):
             raise ConfigError('Xen netback drivers requires scatter-gatter offloading '\
                               'for MTU size larger then 1500 bytes')
 
+def verify_mac_change(ethernet: dict, ethtool: Ethtool):
+    """
+     Verify if ethernet card driver supports changing the interface MAC address.
+     AWS ENA driver has no support for MAC address changes.
+
+    :param ethernet: dictionary which is received from get_interface_dict
+    :type ethernet: dict
+    :param ethtool: Ethernet object
+    :type ethtool: Ethtool
+    """
+    if 'mac' not in ethernet:
+        return None
+    if not ethtool.check_mac_change():
+        raise ConfigError(f'Driver does not suport changing MAC address!')
 
 def verify_allowedbond_changes(ethernet: dict):
     """
@@ -381,6 +395,7 @@ def verify(ethernet):
     verify_flow_control(ethernet, ethtool)
     verify_ring_buffer(ethernet, ethtool)
     verify_offload(ethernet, ethtool)
+    verify_mac_change(ethernet, ethtool)
 
     if 'is_bond_member' in ethernet:
         verify_bond_member(ethernet, ethtool)