DSA config: bat0 does not get into the bridge

[ilario]

In the mailing list, Gothos reported that adding bat0 in the br-lan bridge partially fixed the issues found when using the current LibreMesh code on top of OpenWrt 21.02 and 22.03.

With swconfig (approx OpenWrt 19.07), the interfaces included in br-lan were defined like this in /etc/config/network (see full file in #951 (comment)):

config interface 'lan'
	option type 'bridge'
	option ifname 'eth0.1'
[...]

but with DSA (approx OpenWrt 21.02 and 22.03), now this section only contains the IP configuration, while the bridged interfaces list are defined in another section of the same file:

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'

This causes that, on recent OpenWrt releases, the bat0 interface gets added to the bridge in the old way by proto/lan.lua from lime-system, that does not work with DSA-style configuration:

lime-packages/packages/lime-system/files/usr/lib/lua/lime/proto/lan.lua

Line 59 in 06399e5

uci:set("network", "lan", "ifname", bridgedIfs)

[ilario]

Maybe this is already fixed. To be checked.