Re: Is traceroute supposed to work in user mode networking (slirp) ?

[Ottavio Caruso]

On Sun, 19 Jul 2020 at 15:15, Ottavio Caruso
<ottavio2006-usenet2012@yahoo.com> wrote:
>
> On Sun, 19 Jul 2020 at 12:16, Samuel Thibault <samuel.thibault@gnu.org> wrote:
> >
> > Ottavio Caruso, le dim. 19 juil. 2020 12:07:21 +0100, a ecrit:
> > > On Sun, 19 Jul 2020 at 03:50, Samuel Thibault <samuel.thibault@gnu.org> 
> > > wrote:
> > > > Ottavio Caruso, le mar. 14 juil. 2020 12:15:48 +0100, a ecrit:
> > > > > I cannot get traceroute to work with standard udp from any of my
> > > > > guests.
> > > > >
> > > > > $ traceroute 8.8.8.8
> > > > > traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets
> > > > >  1  * * *
> > > >
> > > > That was because
> > > >
> > > > - libslirp was not forwarding the ttl value, thus always set to 64 hops
> > > > - libslirp was not reporting icmp errors.
> > > >
> > > > I had a try at both, and that indeed seems to be fixing the issue:
> > > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48
> > > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49
> > > >
> > > > > Any clues? Is this intended behaviour? Any workarounds that don't
> > > > > involve tap/tun/bridges?
> > > >
> > > > Not without updating libslirp with the abovementioned patches.
> > >
> > > Thanks Samuel. I've added a comment on the portal, but for the benefit
> > > of qemu-devel:
> > >
> > > Applying this patch on the latest qemu (5.0.90),
> >
> > Did you also apply
> > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 ?
>
> No, because I thought that 49 would include 48. Let me give a try and
> come back. Updates on Gitlab.

Thanks.

https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49#note_573654

When are we going to see this imported into qemu? I'm not extremely
familiar with git modules. I assume this will one day be part of qemu
upstream?


-- 
Ottavio Caruso