On 05/31/2013 12:43 PM, Alan Robertson wrote:

On 05/31/2013 02:46 AM, David Miller wrote:

quoted

From: Alan Robertson <redacted>
Date: Thu, 30 May 2013 16:01:55 -0600

quoted

ndo_dflt_fdb_del is checking for a condition which is opposite that
which ndo_dflt_fdb_add enforces.  ndo_dflt_fdb_add declares an error
if (ndm->ndm_state && !(ndm->ndm_state) & NUD_PERMANENT)) - that is, if the
entry is static.  This is consistent with the failure error message.

On the other hand, ndo_dflt_del() declares an error
if (ndm_state & NUD_PERMANENT) - which is inconsistent with the add
precondition, and inconsistent with its failure message text.
As it is now, you can't delete any entry which add allows to be added -
so entry deletion always fails.

Signed-off-by: Alan Robertson <redacted>

What about the ->ndm_state part of the add() test?  Why not include
that in the del() check?

I had three different thoughts about this:
   1) Replicated the add check in the delete
   2) Do what I did - make it where you can only delete those really
marked as static
   3) Eliminate all delete checks

The problem is -- I'm not sure why the ndm->ndm_state check is in there
-- I don't know how to make that condition occur.  It has the feel of a
check to be made before things are fully initialized - or maybe even
just leftover cruft.

The test  is there to support simultaneous master and self operations. 
The operation on a master may not always require a NUD_PERMANENT state 
(ex: bridge) and we don't want to perform self operations in that instance.

You could make the argument that option (3) is the best -- if it's been
added successfully, you ought to be able to delete it.

Hmm..  _del() always deletes and flags/states don't matter much 
generally.  I agree that the check isn't really needed as it isn't 
really protecting anything.

-vlad

If someone with more knowledge would comment that would be much appreciated!

I'm happy to submit any of these three versions of the patch.  Let me
know what's wanted.