Re: getsockopt(2)

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

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.

Robert Swindells