[pve-devel] [PATCH pve-common 1/2] Inotify: add support for 802.1ad stacked vlans

[Wolfgang Bumiller]

On Mon, Sep 24, 2018 at 09:52:46AM +0200, Alexandre Derumier wrote:
> ---
>  src/PVE/INotify.pm                              | 26 ++++++++++++++++++++++++-
>  test/etc_network_interfaces/t.create_network.pl | 14 +++++++++++++
>  2 files changed, 39 insertions(+), 1 deletion(-)
> 
> diff --git a/src/PVE/INotify.pm b/src/PVE/INotify.pm
> index f837596..de61d79 100644
> --- a/src/PVE/INotify.pm
> +++ b/src/PVE/INotify.pm
> @@ -1432,7 +1433,25 @@ sub __write_etc_network_interfaces {
>      # check vlan
>      foreach my $iface (keys %$ifaces) {
>  	my $d = $ifaces->{$iface};
> -	if ($d->{type} eq 'vlan' && $iface =~ m/^(\S+)\.\d+$/) {
> +	if ($d->{type} eq 'vlan' && $iface =~ m/^(\S+\.\d+)\.\d+$/) {

While 802.1ad seems to be "specified" to be limited to 2 tags, it may
still be nice to just condense this into a single branch:

    if ($d->{type} eq 'vlan' && $iface =~ m/^(\S+(?:\.\d+)*)\.\d+$/) {
        my $parent_name = $1;
        my $parent = $ifaces->{$parent_name};

And then add a 'vlan' type branch before the `not eth/bridge/bond`
branch in the old code?
(And then die if $parent_name contains 2 dots (=~ /\..*\./)).

> +	    my $p = $1;
> +	    my $n = $ifaces->{$p};
> +
> +	    die "vlan '$iface' - unable to find parent '$p'\n"
> +		if !$n;
> +
> +	    die "stacked vlan '$iface' - parent '$p' is not a vlan interface "
> +		if $n->{type} ne 'vlan';
> +
> +	    die "stacked vlan '$iface' - parent '$p' vlan-protocol is not 802.1ad" 
> +		if !$n->{'vlan-protocol'} || $n->{'vlan-protocol'} ne '802.1ad';
> +
> +	    die "stacked vlan '$iface' - vlan-protocol can't be 802.1ad" 
> +		if $d->{'vlan-protocol'} && $d->{'vlan-protocol'} eq '802.1ad';

Btw. is this a restriction of ifupdown2? Or do we just want to do this
for safety?  As from "technical" point of view nothing prevents me from
tripple-tagging. The kernel also happily allows me to add a range of
multiple 802.1Q tags without even using 802.1ad, or mix them.
eg.:
    # ip link add br0.5 link br0 type vlan id 5 protocol 802.1Q
    # ip link add br0.5.6 link br0.5 type vlan id 6 protocol 802.1ad
    # ip link add br0.5.6.7 link br0.5.6 type vlan id 7 protocol 802.1Q
    # ip link add br0.5.6.7.8 link br0.5.6.7 type vlan id 8 protocol 802.1ad

tcpdump shows the expected data - I have no idea what it would do to
the usual switches out there in real networks though ;-)

> +
> +	    &$check_mtu($ifaces, $p, $iface);
> +
> +	} elsif ($d->{type} eq 'vlan' && $iface =~ m/^(\S+)\.\d+$/) {
>  	    my $p = $1;
>  	    my $n = $ifaces->{$p};
>