• Shannon Nelson's avatar
    macvlan: filter out unsupported feature flags · 13fbcc8d
    Shannon Nelson authored
    Adding a macvlan device on top of a lowerdev that supports
    the xfrm offloads fails with a new regression:
      # ip link add link ens1f0 mv0 type macvlan
      RTNETLINK answers: Operation not permitted
    
    Tracing down the failure shows that the macvlan device inherits
    the NETIF_F_HW_ESP and NETIF_F_HW_ESP_TX_CSUM feature flags
    from the lowerdev, but with no dev->xfrmdev_ops API filled
    in, it doesn't actually support xfrm.  When the request is
    made to add the new macvlan device, the XFRM listener for
    NETDEV_REGISTER calls xfrm_api_check() which fails the new
    registration because dev->xfrmdev_ops is NULL.
    
    The macvlan creation succeeds when we filter out the ESP
    feature flags in macvlan_fix_features(), so let's filter them
    out like we're already filtering out ~NETIF_F_NETNS_LOCAL.
    When XFRM support is added in the future, we can add the flags
    into MACVLAN_FEATURES.
    
    This same problem could crop up in the future with any other
    new feature flags, so let's filter out any flags that aren't
    defined as supported in macvlan.
    
    Fixes: d77e38e6 ("xfrm: Add an IPsec hardware offloading API")
    Reported-by: default avatarAlexey Kodanev <alexey.kodanev@oracle.com>
    Signed-off-by: default avatarShannon Nelson <shannon.nelson@oracle.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    13fbcc8d
macvlan.c 43.5 KB