Re: passfd on more platforms

[Bastien ROUCARIES]

On Mon, Mar 14, 2011 at 4:36 PM, Paolo Bonzini <address@hidden> wrote:
> On 03/14/2011 04:19 PM, Bastien ROUCARIES wrote:
>>>
>>> >  But that was a different problem.  That was not related to
>>> > sendfd/recvfd.
>>> >
>>> >  However, there are cases in which you want to send a file descriptor
>>> > as
>>> >  out-of-band messages on a stream socket, and libvirt also has one of
>>> > those.
>>
>> Does sending as oob data process id will fall on the previous trap on
>> SOCK_STREAM  ?
>
> I was using "out-of-band" as a generic term, so SCM_RIGHTS also falls under
> the definition of "out-of-band".
>
>> oob are not implemented for unix so it will work under windows emulation
>
> While using TCP out-of-band data would be an interesting solution for
> Windows, UDP doesn't have out-of-band data.  So, if sendfd/recvfd is going
> to be limited to SOCK_DGRAM, using out-of-band data for Windows is not going
> to work.

Could we know from fd if it is a udp or tcp socket ?

- if tcp send as OOB
- if udp send normally

> On the other hand, if sendfd/recvfd is limited to SOCK_DGRAM, it is okay
> under Windows to send the handle normally as a UDP datagram through
> send/recv (your original plan).
>
> The limitation of sendfd/recvfd to SOCK_DGRAM is perfectly sane---I just
> wanted to point out that it would not be possible for libvirt to use sendfd,
> at least in one of the two scenarios where it is currently using SCM_RIGHTS.
>
> Paolo
>

Bastien