vpp: T8468: Apply MAC address changes on VPP interfaces

The interface config filter stripped the "mac" node, so a MAC address
configured on a VPP interface never reached the dataplane. Allow "mac"
through the filter; VPP applies it to the hardware interface via lcp-sync.
Some DPDK drivers (e.g. vmxnet3) cannot change the MAC and would fail to
bring the interface up. Reject such a change at verify time - both when
setting the MAC and when adding an interface that already has one to VPP.

1 files changed, 20 insertions, 1 deletions

diff --git a/smoketest/scripts/cli/test_vpp.py b/smoketest/scripts/cli/test_vpp.py
index bda2da0f9..16ce29f8b 100755
--- a/smoketest/scripts/cli/test_vpp.py
+++ b/smoketest/scripts/cli/test_vpp.py
@@ -103,6 +103,9 @@ class TestVPP(VyOSUnitTestSHIM.TestCase):
         # out the current configuration :)
         cls.cli_delete(cls, base_path)
         cls.cli_delete(cls, interfaces_path)
+        # drop any pre-existing custom MAC so the MAC test baseline is the
+        # interface hardware address (hw-id)
+        cls.cli_delete(cls, ['interfaces', 'ethernet', interface, 'mac'])
 
     def setUp(self):
         # always forward to base class
@@ -121,8 +124,9 @@ class TestVPP(VyOSUnitTestSHIM.TestCase):
             self.cli_delete(interfaces_path)
             self.cli_commit()
 
-            # delete address for Ethernet interface
+            # delete address and any custom MAC for the Ethernet interface
             self.cli_delete(['interfaces', 'ethernet', interface, 'address'])
+            self.cli_delete(['interfaces', 'ethernet', interface, 'mac'])
             self.cli_commit()
 
         self.assertFalse(os.path.exists(VPP_CONF))
@@ -183,6 +187,21 @@ class TestVPP(VyOSUnitTestSHIM.TestCase):
         self.cli_delete(['interfaces', 'ethernet', interface, 'mtu'])
         self.cli_commit()
 
+        # A custom MAC address must reach the VPP dataplane, and removing it must
+        # restore the hardware address (hw-id). Rejection of drivers that cannot
+        # change the MAC (e.g. vmxnet3) is not covered here, as the CI dataplane
+        # NIC uses a supported driver.
+        hw_mac = VPPControl().get_mac(interface)
+        mac = '02:00:de:ad:be:01'
+        self.cli_set(['interfaces', 'ethernet', interface, 'mac', mac])
+        self.cli_commit()
+        self.assertEqual(VPPControl().get_mac(interface), mac)
+
+        # removing the custom MAC reverts to the hardware address (hw-id)
+        self.cli_delete(['interfaces', 'ethernet', interface, 'mac'])
+        self.cli_commit()
+        self.assertEqual(VPPControl().get_mac(interface), hw_mac)
+
         # set interface address as dhcp
         self.cli_set(['interfaces', 'ethernet', interface, 'address', 'dhcp'])
         self.cli_commit()