[PATCH] libwbclient clear pointer on bad read

[Volker Lendecke]

On Thu, Jan 15, 2015 at 05:42:15PM +0000, Matthew Newton wrote:
> Separating the two layers looks like a good idea, but I can't
> really commit to looking at that for now.

Understood. That's a bigger task.

> > This would be my preferred approach, but if you need
> > something quicker, probably the pthread_setspecific approach
> > might be okay.
> 
> I've had success with using pthread_setspecific and friends.  Have
> only updated wb_common.c for now (which is where I needed the code
> to work) - attached. If this code is acceptable then I can try and
> have a look at updating the other global variables in other parts
> of the library.
> 
> With this patch and FreeRADIUS linked to libwbclient for NTLM
> authentications from multiple threads, it's looking perfect with
> no errors any more, which is good.

This is really great. The patch looks very simple!

Stylistically I'd do it a bit differently though: I'd not at all use
macros.

I'd make it two patches: First convert all access to the global variables
to a two-step process: First call a function like winbindd_fd_ptr()
returning an int* and then after that access the fd via that pointer. That
would be the first patch. Second patch would be to introduce the
thread-specific piece, just adding a #ifdef HAVE_PTHREAD version of it
not returning &winbindd_fd but the thread specific space.

Sounds reasonable?

Volker

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