Re: passfd on more platforms

[Paolo Bonzini]

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.

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