/usr/lib/python3.6/site-packages/neutron/agent/linux/ip_lib.py error from ip_lib.privileged.get_link_vfs

openstack_victoria_ip_lib_error.txt

### working victoria environment:
>>> ip_lib.privileged.get_link_vfs('pt0', '')
{0: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 1: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 2: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 3: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 4: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 5: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 6: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 7: {'mac': 'b6:ff:ef:5d:5f:e2', 'link_state': 0}}
>>> ip_lib.privileged.get_link_vfs('pt1', '')
{0: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 1: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 2: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 3: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 4: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 5: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 6: {'mac': '00:00:00:00:00:00', 'link_state': 0}, 7: {'mac': '00:00:00:00:00:00', 'link_state': 0}}


### broken victoria environment:
## 63 VFs configured and enabled:
cat /sys/class/net/ens2f1/device/sriov_totalvfs 
63


ip link show ens2f1 | wc -l
65


>>> ip_lib.privileged.get_link_vfs('ens2f0', '')
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1345, in _ft_decode_generic
    self.decode_nlas(offset)
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1470, in decode_nlas
    offset)
struct.error: unpack_from requires a buffer of at least 4 bytes

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.6/site-packages/oslo_privsep/priv_context.py", line 247, in _wrap
    return self.channel.remote_call(name, args, kwargs)
  File "/usr/lib/python3.6/site-packages/oslo_privsep/daemon.py", line 224, in remote_call
    raise exc_type(*result[2])
TypeError: can not serialize 'error' object


### what is interesting, i don't see this error for other non sriov interfaces so prbly this is not pyroute2 related:
>>> ip_lib.privileged.get_link_vfs('eno3', '')
{}

### update 20210602
### after commenting out line 441 there is another exception:
### https://github.com/openstack/neutron/blob/stable/victoria/neutron/privileged/agent/linux/ip_lib.py#L441
>>> ip_lib.privileged.get_link_vfs('ens2f0', '')
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1345, in _ft_decode_generic
    self.decode_nlas(offset)
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1470, in decode_nlas
    offset)
struct.error: unpack_from requires a buffer of at least 4 bytes

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1345, in _ft_decode_generic
    self.decode_nlas(offset)
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1470, in decode_nlas
    offset)
struct.error: unpack_from requires a buffer of at least 4 bytes

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.6/site-packages/neutron/privileged/agent/linux/ip_lib.py", line 443, in get_link_vfs
    link = _run_iproute_link('get', device, namespace=namespace, ext_mask=1)[0]
  File "/usr/lib/python3.6/site-packages/neutron/privileged/agent/linux/ip_lib.py", line 263, in _run_iproute_link
    return ip.link(command, index=idx, **kwargs)
  File "/usr/lib/python3.6/site-packages/pyroute2/iproute/linux.py", line 1350, in link
    msg_flags=msg_flags)
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/nlsocket.py", line 376, in nlm_request
    return tuple(self._genlm_request(*argv, **kwarg))
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/nlsocket.py", line 869, in nlm_request
    callback=callback):
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/nlsocket.py", line 379, in get
    return tuple(self._genlm_get(*argv, **kwarg))
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/nlsocket.py", line 704, in get
    raise msg['header']['error']
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/nlsocket.py", line 177, in parse
    msg.decode()
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/rtnl/ifinfmsg/__init__.py", line 1092, in decode
    nlmsg.decode(self)
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1016, in decode
    self._ft_decode(self, offset)
  File "/usr/lib/python3.6/site-packages/pyroute2/netlink/__init__.py", line 1348, in _ft_decode_generic
    raise NetlinkNLADecodeError(e)
pyroute2.netlink.exceptions.NetlinkNLADecodeError: unpack_from requires a buffer of at least 4 bytes

pyroute2 bug: svinota/pyroute2#751