[PATCH v2 13/14] Devices.Device: handle RTM_NEWLINK messages without any IFLA_ADDRESS

[Jan Tluka]

There are cases when IFLA_ADDRESS is not included in the netlink
message, for example when vxlan device is created with gpe flag:

ip link add vxlan0 type vxlan external gpe

When the IFLA_ADDRESS is not present in the message the None value
is passed to hwaddress() parser function that raises an exception.

A check is added to hwaddr property whether the IFLA_ADDRESS attribute
is present. If it's not the parser function is bypassed and None is
returned.

Signed-off-by: Jan Tluka <jtluka(a)redhat.com&gt;
---
 lnst/Devices/Device.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lnst/Devices/Device.py b/lnst/Devices/Device.py
index fd5ef86b..adebd117 100644
--- a/lnst/Devices/Device.py
+++ b/lnst/Devices/Device.py
@@ -416,7 +416,10 @@ class Device(object, metaclass=DeviceMeta):
         Returns a HWAddress object representing the hardware address of the
         device as reported by the kernel.
         """
-        return hwaddress(self._nl_msg.get_attr("IFLA_ADDRESS"))
+        if self._nl_msg.get_attr("IFLA_ADDRESS"):
+            return hwaddress(self._nl_msg.get_attr("IFLA_ADDRESS"))
+        else:
+            return None
 
     @hwaddr.setter
     def hwaddr(self, addr):
-- 
2.26.3