Re: [ANNOUNCE] libkcapi v0.12.0 released

[Stephan Mueller <smueller@chronox.de>]

Am Donnerstag, 27. Oktober 2016, 18:53:45 CEST schrieb Jeffrey Walton:

Hi Jeffrey,


> >> preprocessor macros we can use to guard it?
> > 
> > I am not entirely sure I understand the question.
> 
> See, for example,
> https://github.com/openssl/openssl/blob/master/engines/afalg/e_afalg.c
> 
> The versions are kind of arbitrary because there's no easy way to tell
> when the gear is available. If I recall from researching things, there
> were two components needed for afalg, and they were supposedly
> available back to later 2.x kernels.
> 
> Things should "just work" for 3.x and 4.x kernels. But if "too early"
> a kernel is encountered, then users experience the spectrum from
> compile problems to unexplained runtime errors.

I see. There are guards around zerocopy.

AF_ALG appeared with 2.6.38 / 3.0 which already had zerocopy.

I will try a 3.0 kernel with my current lib to see whether it works out of the 
box and apply fixes and guards if it does not.

But I am not sure whether I should guard anything for 2.x kernels where we 
know that some folks simply backported the AF_ALG interface.


Thanks a lot for the reminder.

Ciao
Stephan