Realtek 8187 (RTL8187) driver

jivanpal

Apparently the rtl8187 kernel module which serves as a driver for the RTL8187/RTL8187B chipset is included in the EL7 kernel, but this is not the case in the XCP-ng 8.2 kernel (4.19.0+1), nor does a package seem to exist for this module. I would be grateful if this could be added, as I am trying to use a Netgear WG111v3 USB Wi-Fi dongle (vendor/device ID 0846:4260, RTL8187B chipset) for homelab purposes.

olivierlambert

Hi,

How would you like to use WiFi? IIRC, you can't use your WiFi as a bridge device anyway. Why not doing USB passthrough of the dongle to your VM?

jivanpal

@olivierlambert Just want to have all the VMs use the same connection as the hypervisor, same as I would with Ethernet. Any particular reason that bridging Wi-Fi isn't supported? I would've thought that the Wi-Fi interface showing up in dom0 under ip link is enough, as then after doing xe pif-scan it would show up in XOA under New > Network > Interface dropdown, no?

Didn't think of USB passthrough, but that would restrict only one VM to using the interface, correct?

olivierlambert

Question for @fohdeesha

fohdeesha

@jivanpal I think trying to get OpenVswitch (our underlying network layer) managing and using a wifi dongle for core hypervisor networking would be a nightmare, and you'd probably need to install some extra packages to handle the authentication / WPA management etc - then of course there's zero guarantee OVS wouldn't overwrite or revert any of this custom stuff for said interface (OVS was not designed to work with wifi)

Not to mention you'd have to have a relatively hackable AP, one that will allow the dongle to source a lot of different MAC addresses, which is pretty rare. From OVS's own docu:

jivanpal

@fohdeesha Very interesting, thanks for the info! I did a double-take at the notion that wireless APs rely on the MAC address for authenticity... that's what the session key is for! But then I realised that the AP needs to be able to map IP/MAC address to session key for incoming packets, so it makes sense; we'd need one session per MAC address.

Welp, I guess it's cable-running time...

I do wonder, though: could the hypervisor act as the gateway for a subnet containing the guests, so that only the hypervisor is using the wireless connection? I don't know how challenging that would be to implement in XCP-ng, but I expect there'd be security implications, and one would still need a router that allows you to manually configure routes. Although I don't think I've ever come across a residential router/gateway that doesn't allow that, I haven't messed around with them, and I expect the ISP would just remotely reset custom routes after a restart, which would be a nuisance.