Re: Bugreport: macvlan device choosing wrong parent device

[Ulrich Ölmann <u oelmann pengutronix de>]

Hi Beniamino,

On Wed, Sep 27, 2017 at 10:56:30AM +0200, Beniamino Galvani wrote:
> On Tue, Sep 26, 2017 at 04:04:38PM +0200, Ulrich Ölmann wrote:
> > I applied your patch and NetworkManager avoids the unmanaged device eth0 to
> > instead create the virtual MAC VLAN device on top of eth1 now. Great! :-)
> > Looking into the journal, however, I still see a warning saying
> >
> >     manager: (link-local) can't register the device with manager: A device with ifindex 10 already exists
> >
> > Do we have to expect any side-effects because of this?
>
> This is a bug, however it should be harmless. I'll post some patches
> to fix this.

your patches look good to me and applying them results in NM doing the right
thing again. Thanks!

However, if I modify my setup a little bit by _not_ explicitely declaring eth0
to be unmanaged in NetworkManager.conf NM now avoids to touch eth0 as it has
already been configured outside (remeber: I use eth0 for NFS root). Starting NM
with both connections being present it brings up "routable" on eth1 and creates
the new MAC VLAN device link-local now on top of eth0. This is what I would
expect and what I actually want NM to do. Unfortunately it does not start the
connection "link-local" on link-local:

    root@host:~ nmcli
    eth0: connected to eth0
            "eth0"
            ethernet (pch_gbe), 00:13:95:0A:4B:30, hw, mtu 1500
            ip4 default
            inet4 192.168.24.227/16
            inet6 fe80::213:95ff:fe0a:4b30/64
            route6 ff00::/8

    eth1: connected to routable
            "NETGEAR FA120 Adapter"
            ethernet (asix), 00:09:5B:BE:62:71, hw, mtu 1500
            inet4 192.168.24.156/16
            inet6 fe80::209:5bff:febe:6271/64
            route6 ff00::/8

    link-local: disconnected
            "link-local"
            macvlan, sw, mtu 1500

    [...]

The journal now tells me:

    device (eth0): link connected
    manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
    manager: (link-local): new Macvlan device (/org/freedesktop/NetworkManager/Devices/3)
    keyfile: add connection in-memory (132747e6-f1f1-46f3-89d4-aef150234a5d,"eth0")
    device (eth0): state change: unmanaged -> unavailable (reason 'connection-assumed', internal state 
'external')
    device (eth0): state change: unavailable -> disconnected (reason 'connection-assumed', internal state 
'external')
    device (eth0): Activation: starting connection 'eth0' (132747e6-f1f1-46f3-89d4-aef150234a5d)
    device (eth1): link connected
    manager: (eth1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/4)
    device (eth1): state change: unmanaged -> unavailable (reason 'managed', internal state 'external')
    manager: (sit0): new IPTunnel device (/org/freedesktop/NetworkManager/Devices/5)
--> manager: (link-local) can't register the device with manager: A device with ifindex 8 already exists
    device (eth0): state change: disconnected -> prepare (reason 'none', internal state 'external')
    device (link-local): state change: unmanaged -> unavailable (reason 'managed', internal state 'external')
    device (link-local): link connected
    device (eth0): state change: prepare -> config (reason 'none', internal state 'external')
    device (eth1): state change: unavailable -> disconnected (reason 'none', internal state 'managed')
    device (eth0): state change: config -> ip-config (reason 'none', internal state 'external')
    policy: auto-activating connection 'routable'
    device (link-local): state change: unavailable -> disconnected (reason 'none', internal state 'managed')
    device (eth0): state change: ip-config -> ip-check (reason 'none', internal state 'external')
    device (eth1): Activation: starting connection 'routable' (7ac61f21-bf59-4c4c-ae38-51ce131b2afc)
    device (eth0): state change: ip-check -> secondaries (reason 'none', internal state 'external')
    device (eth1): state change: disconnected -> prepare (reason 'none', internal state 'managed')
    manager: NetworkManager state is now CONNECTING
    device (eth0): state change: secondaries -> activated (reason 'none', internal state 'external')
    manager: NetworkManager state is now CONNECTED_SITE
    policy: set 'eth0' (eth0) as default for IPv4 routing and DNS
    device (eth0): Activation: successful, device activated.
    device (eth1): state change: prepare -> config (reason 'none', internal state 'managed')
    device (eth1): state change: config -> ip-config (reason 'none', internal state 'managed')
    dhcp4 (eth1): activation: beginning transaction (timeout in 45 seconds)
    dhcp4 (eth1):   address 192.168.24.156
    [...]
    dhcp4 (eth1): state changed unknown -> bound
    device (eth1): state change: ip-config -> ip-check (reason 'none', internal state 'managed')
    device (eth1): state change: ip-check -> secondaries (reason 'none', internal state 'managed')
    device (eth1): state change: secondaries -> activated (reason 'none', internal state 'managed')
    [...]
    device (eth1): Activation: successful, device activated.
    manager: startup complete

This is expected behaviour now, right? (Because of connection "link-local" using
a UUID inside its parent property and this UUID being found in a connection that
has been applied to a different device than what link-local's actual parent is?)
Again explicitely using "parent=eth0" gives me what I want.

Best regards
Ulrich
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