• David S. Miller's avatar
    vlan: Fix header ops passthru when doing TX VLAN offload. · 2205369a
    David S. Miller authored
    When the vlan code detects that the real device can do TX VLAN offloads
    in hardware, it tries to arrange for the real device's header_ops to
    be invoked directly.
    
    But it does so illegally, by simply hooking the real device's
    header_ops up to the VLAN device.
    
    This doesn't work because we will end up invoking a set of header_ops
    routines which expect a device type which matches the real device, but
    will see a VLAN device instead.
    
    Fix this by providing a pass-thru set of header_ops which will arrange
    to pass the proper real device instead.
    
    To facilitate this add a dev_rebuild_header().  There are
    implementations which provide a ->cache and ->create but not a
    ->rebuild (f.e. PLIP).  So we need a helper function just like
    dev_hard_header() to avoid crashes.
    
    Use this helper in the one existing place where the
    header_ops->rebuild was being invoked, the neighbour code.
    
    With lots of help from Florian Westphal.
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    2205369a
vlan_dev.c 21.4 KB