Re: [PATCH] GnuTLS support on Woe32

[Claudio Bley]

At Mon, 07 Mar 2011 22:03:46 +0100,
Claudio Bley wrote:
> 
> At Sun, 06 Mar 2011 18:58:46 +0200,
> Eli Zaretskii wrote:
> > > +#ifdef WINDOWSNT
> > > +#  include "sys/socket.h"
> > > +#  include "systime.h"
> > > +
> > > +/* we need to translate Winsock errors because GnuTLS only checks
> > > + * for EAGAIN or EINTR */
> > > +static int
> > > +wsaerror_to_errno(int err)
> > > +{
> > > +  switch (err)
> > > +    {
> > > +    case WSAEWOULDBLOCK:
> > > +      return EAGAIN;
> > > +    case WSAEINTR:
> > > +      return EINTR;
> > > +    default:
> > > +      return err;
> > > +    }
> > > +}
> > 
> > Why is this function needed?  Can you extend w32.c:set_errno instead
> > (if it doesn't already support all the values of WSA* errors that you
> > need)?
> 
> Yes, I could extend w32.c:set_errno, if I move the Windows-specific
> function to w32.c proper...

I just had a look at this again. It's not so easy.

For GnuTLS, I have to map WSAEWOULDBLOCK to EAGAIN. This is set in
stone.

Doing this in w32.c:set_errno would break a lot of other stuff that
checks for EWOULDBLOCK because that happens to be #define'd to
WSAEWOULDBLOCK in sys/socket.h:129 (which seems reasonable after all).

It works alright when EWOULDBLOCK is #define'd to EAGAIN. In the end
it doesn't matter what EWOULDBLOCK is defined to because on Windows
MinGWs GCC doesn't define it at all, MSVC has it, but WinSock uses
it's own error codes anyway.

> > > +static ssize_t
> > > +emacs_gnutls_pull(gnutls_transport_ptr_t p, void* buf, size_t sz)
> > 
> > Can we move the Windows-specific functions to w32.c, and only call
> > them from gnutls.c?  I think we want to keep the Windows-related code
> > outside w32*.c to the bare minimum.
> 
> OK.

Maybe the GnuTLS specific stuff should also be kept to the bare
minimum outside of gnutls.c?

Considering that these functions would have to be non-static in this
case to be accessible by gnutls.c.

- Claudio