Re: [PATCH] net/tls: Fix return values for setsockopt

(there is a v2, in case you missed)

On Wed, 4 Dec 2019 14:22:55 -0500, Willem de Bruijn wrote:

On Tue, Dec 3, 2019 at 6:08 PM Jakub Kicinski wrote:

quoted

On Tue,  3 Dec 2019 23:44:58 +0100, Valentin Vidic wrote:  

quoted

ENOTSUPP is not available in userspace:

  setsockopt failed, 524, Unknown error 524

Signed-off-by: Valentin Vidic <redacted>  

I'm not 100% clear on whether we can change the return codes after they
had been exposed to user space for numerous releases..  

This has also come up in the context of SO_ZEROCOPY in the past. In my
opinion the answer is no. A quick grep | wc -l in net/ shows 99
matches for this error code. Only a fraction of those probably make it
to userspace, but definitely more than this single case.

If anything, it may be time to define it in uapi?

No opinion but FWIW I'm toying with some CI for netdev, I've added a
check for use of ENOTSUPP, apparently checkpatch already sniffs out
uses of ENOSYS, so seems appropriate to add this one.

quoted

But if we can - please fix the tools/testing/selftests/net/tls.c test
as well, because it expects ENOTSUPP.  

Even if changing the error code, EOPNOTSUPP is arguably a better
replacement. The request itself is valid. Also considering forward
compatibility.

For the case TLS version case?