FreeLists / openbeosnetteam / [openbeosnetteam] Re: socketpair() implementation

["info@xxxxxxxxxxxxxx" <info@xxxxxxxxxxxxxx>]

I know what it means, what I want is an example of why you would use it. 
 What's the purpose of "creating a pair of connected sockets".


Jérôme Duval wrote:
> > From http://www.opengroup.org/onlinepubs/009695399/functions/socketpair.html
>
> "create a pair of connected sockets"
>
> Note the word connected, it is important.
> Though I don't know what means exactly "unbound pair" ...
>
> Bye,
> Jérôme
>
> Selon "info@xxxxxxxxxxxxxx" <info@xxxxxxxxxxxxxx>:
>
>
> > Can anybody tell me why someone would use socketpair instead of just
> > creating two sockets?  I can't think of a reason to use it.
> >
> > Philippe Houdoin wrote:
> >
> > > Hi Jerome and teammates ;-)
> > >
> > >
> > >
> > > > Please have a look at http://www.haiku-os.org/bugzilla/show_bug.cgi?id=52
> >
> > to
> >
> > > > give feedback or comments. socketpair() isn't on BeOS, but it's kind of
> > > > expected to be here IMO.
> > >
> > >
> > > Well, as it's missing for POSIX 1003.1 compliance, I guess supporting it
> >
> > will be
> >
> > > great. Not mandatory for R1, thought, but it's not like it's that hard to
> > > implement.
> > >
> > >
> > >
> > > > I added a socketpair() prototype in our header sys/socket.h.
> > >
> > >
> > > I saw this, yes.
> > >
> > >
> > >
> > > > My opinion about implementation would be to have a socketpair() in
> > > > src/kits/network/libsocket/socket.c which does (for AF_INET at least):
> > > > - calls socket() twice to have two sockets.
> > > > - call a new ioctl to have the network stack do the socketpair hard job :
> > > > bind(), listen(), connect(), accept()
> > > > - close the listening socket.
> > >
> > >
> > > Sounds good to me, indeed.
> > > BTW, these sockets are supposed to be unbounded.
> > >
> > >
> > >
> > > > As I never tested the Haiku network part, maybe I'm not the right person to
> > > > code this.
> > >
> > >
> > > Then just implement a noop socketpair() in socket.c (both in libsocket and
> >
> > in
> >
> > > libnet variant) and I'll self assign the task to implement it later.
> > >
> > > I don't consider this as urgent as reaching beta stage of OpenGL Kit and
> >
> > the
> >
> > > network stack missing features: DHCP, 802.11 support.
> > > Maybe that's because I never used socketpair() so far ;-)
> > >
> > > - Philippe