udev script shortcuts ifup-scripts

[Hadmut Danisch]

Hi,

I just ran into a problem. I've configured a bridge as a virtual lan (for lxc, lxd, and these things), but also configured an USB Ethernet dongle to be part of the bridge.

If the dongle is present at boot time or if the dongle is put in while the bridge is down, then

/lib/udev/bridge-network-interface

tries to take the bridge up. Nice.

But it does not call ifup, instead it directly calls

IFACE=$port /etc/network/if-pre-up.d/vlan

This ifup is not aware that the interface is up and still thinks it would be down, and all the other settings (up/down-scripts ...) are not executed. Breaks functionality (and can be a security problem, since firewall settings my be skipped.)

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: bridge-utils 1.5-9ubuntu2
ProcVersionSignature: Ubuntu 4.8.0-32.34-generic 4.8.11
Uname: Linux 4.8.0-32-generic x86_64
NonfreeKernelModules: zfs zunicode zcommon znvpair zavl
ApportVersion: 2.20.3-0ubuntu8.2
Architecture: amd64
CurrentDesktop: XFCE
Date: Fri Dec 23 11:31:43 2016
Dependencies:
 gcc-6-base 6.2.0-5ubuntu12
 libc6 2.24-3ubuntu2
 libgcc1 1:6.2.0-5ubuntu12
InstallationDate: Installed on 2016-04-22 (244 days ago)
InstallationMedia: Lubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420)
SourcePackage: bridge-utils
UpgradeStatus: Upgraded to yakkety on 2016-10-17 (67 days ago)

[Hadmut Danisch (hadmut)]

More trouble with that udev script:

Plugging in a USB ethernet dongle into a bridge which lists it as a port does not work. It takes an additional

ifconfig up

to switch the ethernet interface on.

[Christian Ehrhardt  (paelzer)]

Thank you hadmut for taking the time to report this bug and helping to make Ubuntu better.
It seems this was missed in the Christmas time :-/

I currently can't find a matching bug, but I'm pretty convinced I've heard most of the context before in discussions around networkd/netplan.
It is somewhat related to the old discussion in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=673490 (in regard to the layering violation), but that is not what I'm looking for.

Until I find the discussion I could link I'll mark it as confirmed for now.
But this always is a topic with a huge complexity due to the interdependencies of the tools.

[Andreas Hasenack (ahasenack)]

artful still has the same /lib/udev/bridge-network-interface script in its bridge-utils package, fwiw.

[Christian Ehrhardt  (paelzer)]

We are - as always - trying to clean and recheck old bugs.
This - sadly - clearly is one of them.
The situation is still correct, but with the full switch to networkd and netplan as well as the demotion of ifupdown in later versions of Ubuntu this has become even less important. And it didn#t even find enough importance/attendence before :-/

I'm retagging this as a Xenial/Bionic issue, because later releases would just work totally different anyway.