Re: algif for compression?

["Stephan Müller" <smueller@chronox.de>]

Am Montag, 3. April 2017, 08:10:19 CEST schrieb abed mohammad kamaluddin:

Hi abed,

> Hi Herbert,
> 
> We have implemented algif acomp interface for user space applications
> to utilize the kernel compression framework and the hardware drivers
> using it and have been testing it using userspace zlib library.
> 
> However, what we find lacking in the existing acomp implementation is
> the ability to pass context data between the applications and the
> drivers using the acomp interface. Currently the interface only allows
> src/dest data  and a flag argument with each request. There are two
> context pointers, one in acomp_req and another in crypto_tfm but they
> are for internal use and not available to applications through the
> api's. Would it be acceptable to add fields that need to be
> communicated b/w the driver and applications like history,
> csum/adler32, EOF, stream ctx  to acomp_req.
> 
> Or is there any other way, which I may have missed, through which we
> can pass ctx data between applications and drivers while using the
> kernel compression framework?

If you follow the AF_ALG implementations that are currently in the kernel, a 
calling application receives two file descriptors. The first file descriptor 
is the reference to a tfm, the second is the reference to a particular 
request.

Wouldn't those file descriptors be the reference you are looking for?

Ciao
Stephan