Re: getsockopt(2)

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

christos%astron.com@localhost (Christos Zoulas) wrote:
>In article <x7r2u3inin.fsf%ren.fdy2.co.uk@localhost>,
>Robert Swindells  <rjs%fdy2.co.uk@localhost> wrote:
>>
>>christos%astron.com@localhost (Christos Zoulas) wrote:
>>>In article <x7wp3xi6py.fsf%ren.fdy2.co.uk@localhost>,
>>>Robert Swindells  <rjs%fdy2.co.uk@localhost> wrote:
>>>>
>>>>I wrote:
>>>>>Does anyone know why we don't use the input 'optlen' parameter to the
>>>>>getsockopt(2) syscall, we do write back to it on return.
>>
>>[snip]
>>
>>>Neither FreeBSD or OpenBSD copyin the value, but I think it is ok to
>>>do so if it is useful to read the input to deduce the output. But that
>>>would make the call asymetric, so let's examine the examples where this
>>>is useful first.
>>
>>FreeBSD does copyin the value, but the code to do it is scattered around
>>the kernel, search for sooptcopyin() in their tree.
>
>Yes, aren't most of the in the sosetopt paths? I am looking for the sogetopt
>paths... I have not looked carefully to see if there are any.

It is done for TCP_CCALGOOPT and for all the SCTP options.

I had reused the FreeBSD userland for SCTP, I was trying to test it
before committing the final bits. I would prefer not to have to
redesign it.