[Qemu-devel] Re: Status of user-mode networking for win32

["Mike Nordell" <tamlin@algonet.se>]

I wrote:

> I vote to commit the patch for ne2000, aligning on 16-bit, not 32-bit.
>
> It made (among other things) "ipconfig /renew" work in Windows 2000 guest,
> on Windows 2000 host.

Seems I opened my mouth too early. With this patch in place, it seems that
every second time I boot the Windows 2000 guest in QEMU I get a somewhat
working connection between slirp and the guest OS (I've been able to ICMP
ping the host, using it's real IP interface, but ping-ing other hosts on the
net does not work(*)). The other times it just won't talk to it as it should
(even that I do get slirp debug output).

If it works the same or not without the patch I haven't yet tested. Maybe
it's better with it, maybe not - I just wanted to retract my absolute
support of the patch ASAP until I've been able to reasearch the problem
further.

(*) I believe the largest part of the problem is that slirp is so far only
aware of errno. In Win32, since the C runtime library is just that, a
library, while on POSIX I believe it's an integral part of the environment,
no e.g. socket errors propagate to errno - and things go south. As an
example I can mention a recvfrom() (on a UDP socket, obviously) that fails,
and while errno claims 9 (EBADF - "Bad file descriptor"), WSAGetLastError
says WSAECONNRESET - which means the previous send resulted in an ICMP port
unreachable.

/Mike