[PATCH] Re: IP_MULTICAST_IF et all / Winsock[2] value conflict

Brian Ford Brian.Ford@flightsafety.com
Tue Oct 18 14:32:00 GMT 2005

On Mon, 17 Oct 2005, Corinna Vinschen wrote:
> On Oct  3 12:25, Brian Ford wrote:
> > On Mon, 3 Oct 2005, Corinna Vinschen wrote:
> > > No, let's change it.  Winsock2 is the way to go.  Winsock1 is just old
> > > stuff.  Since Cygwin is using Winsock2 when running on a 98 system or
> > > above,

In some ways, I now believe this was not exactly true.

It appeared that [set|get]sockopt was formerly autoloaded from wsock32, so
maybe the values were correct.  When I tried to investigate this further,
I got really confused about how this was supposed to work together.

Neither of the two possible values for IP_MULTICAST_IF seemed to work
correctly in my limited testing.  But, at the same time, changing the
values for IP_ADD_MEMBERSHIP did not exhibit the failure described in the
MSDN KB article either?  At this point, I ran out of time and my test
system was shipped to a demo :-(.

> > > and since applications using the old/wrong Winsock1 values are
> > > broken right now anyway, there's no gain to keep the old values and
> > > force all new (and supposed to be working) applications to go through
> > > a translation stage.  Let the old applications suffer, not the new ones.
> >
> > That's a reasonably convincing argument.  I just wish fixing this didn't
> > require an application recompile.  I didn't think that was the Cygwin
> > philosophy...<time passes>  Oh, you mean do the translation only for older
> > apps?  That sounds good.
> I've just applied a patch, which does all of that, removing the last remains
> of Winsock1 support, as well as changing the IPPROTO_IP values in
> include/cygwin/socket.h to the new Winsock2 values, as well as checking
> for the applications ABI version number so that older applications get
> the values translated into the new Winsock2 values in setsockopt/getsockopt
> on the fly.

Thank you.  I didn't really mean for you to have to do it, but I haven't
had time to get back into the confusion.

> This still needs some testing.

As soon as my demo system comes back (next week or the week after), I'll
do so.

Brian Ford
Senior Realtime Software Engineer
VITAL - Visual Simulation Systems
FlightSafety International
the best safety device in any aircraft is a well-trained pilot...

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