netdev user,restrict=on prevents forwarded ports from being accessed from other systems

[Nathan Rennie-Waldock]

I've got a guest only network and I'm wanting to access SSH on one of the guests externally.
I'm using -netdev user,id=usernet0,hostfwd=tcp::2222-:22,restrict=yes -device virtio-net-pci,netdev=usernet0
to forward 2222 to 22 in the guest.

The docs state:
restrict=on|off

    If this option is enabled, the guest will be isolated, i.e. it will not be able to contact the host and no guest IP packets will be routed over the host to the outside. This option does not affect any explicitly set forwarding rules.

However, with restrict=on, the forwarded port is only accessible from the host. Other systems receive no data.

This was tested with qemu 2.8. Changelog for 2.9 doesn't mention any (relevant) user networking changes, so that should also fail.

[Thomas Huth (th-huth)]

slirp (i.e. user networking) has been moved to a separate project... does this problem still persist with the latest version of QEMU? If so, could you please report it to the libslirp project instead:

https://gitlab.freedesktop.org/slirp/libslirp/-/issues

Thanks!

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]