test-network: check existence of kernel bug

This adds checks for the kernel bug caused by
3ddc2231c8,
it will be fixed by
https://patchwork.kernel.org/project/netdevbpf/patch/20240510072932.2678952-1-edumazet@google.com/

test/test-network/systemd-networkd-tests.py

@@ -269,6 +269,22 @@ def expectedFailureIfNetdevsimWithSRIOVIsNotAvailable():
 
     return f
 
+def expectedFailureIfKernelReturnsInvalidFlags():
+    '''
+    This checks the kernel bug caused by 3ddc2231c8108302a8229d3c5849ee792a63230d.
+    It will be fixed by the following patch:
+    https://patchwork.kernel.org/project/netdevbpf/patch/20240510072932.2678952-1-edumazet@google.com/
+    '''
+    def f(func):
+        call_quiet('ip link add dummy98 type dummy')
+        call_quiet('ip link set up dev dummy98')
+        call_quiet('ip address add 192.0.2.1/24 dev dummy98 noprefixroute')
+        output = check_output('ip address show dev dummy98')
+        remove_link('dummy98')
+        return func if 'noprefixroute' in output else unittest.expectedFailure(func)
+
+    return f
+
 # pylint: disable=C0415
 def compare_kernel_version(min_kernel_version):
     try:
@@ -2823,6 +2839,7 @@ class NetworkdNetworkTests(unittest.TestCase, Utilities):
 
         check_json(networkctl_json())
 
+    @expectedFailureIfKernelReturnsInvalidFlags()
     def test_address_static(self):
         copy_network_unit('25-address-static.network', '12-dummy.netdev', copy_dropins=False)
         self.setup_nftset('addr4', 'ipv4_addr')
@@ -6295,6 +6312,7 @@ class NetworkdDHCPClientTests(unittest.TestCase, Utilities):
         self.assertIn('DHCPREPLY(veth-peer)', output)
         self.assertIn('sent size:  0 option: 14 rapid-commit', output)
 
+    @expectedFailureIfKernelReturnsInvalidFlags()
     def test_dhcp_client_ipv4_only(self):
         copy_network_unit('25-veth.netdev', '25-dhcp-server-veth-peer.network', '25-dhcp-client-ipv4-only.network')