Setting a static IP on the WAN port

[ilario]

I just tried to set a static IPv4 on the WAN port connected to an internet-providing router and just realized that Babeld does not share the default route from this interface.

The configuration I inserted in /etc/config/lime-node is this:

config net lm_hwd_openwrt_wan
	option autogenerated 'false'

config net wan_static
	option linux_name 'wan'
	list protocols 'static'
	option static_ipv4 '192.168.1.2/24'
	option static_gateway_ipv4 '192.168.1.1'

(as documented in lime-example.txt, the first section is for avoiding the lime-hwd-openwrt-wan to configure the wan interface to use dhcp client, the second is creating a section setting the static IP).

The default route is present, but it does not get shared with the rest of the network.

I suppose this happens because babeld-auto-gw-mode is looking for the default route only on the section wan of /etc/config/network:

lime-packages/packages/babeld-auto-gw-mode/files/etc/watchping/wan-ok.d/babeld-gw

Line 14 in 1aa97c6

local wan4_status = conn:call("network.interface.wan", "status", {})

but the configuration above generates the route in a section named lm_net_wan_static:

config interface 'wan'
	option device 'wan'
	option proto 'none'

config interface 'wan6'
	option device 'wan'
	option proto 'none'

[...]

config interface 'lm_net_wan_static'
	option proto 'static'
	option auto '1'
	option ifname 'wan'
	option ipaddr '192.168.1.2'
	option netmask '255.255.255.0'
	option gateway '192.168.1.1'

[a-gave]

Hi, add few notes and a question on this.
This reminds me of a gateway where i left dhcp as proto for wan.
Testing on that gateway and replacing network.interface.wan with lm_net_eth0_2_static (in my case)
in /etc/watchping/wan-{ok,fail}.d/babeld-gw allows to use the static ip:

local wan4_status = conn:call("network.interface.lm_net_eth0_2_static", "status", {})

To avoid this manual change i tried to rewrite both scripts to not use ubus
but to look only at ip route as in the scripts copied below, for retrieving the correct route and device.

But testing this i noticed that watchping will check only wan, wan6 and client-wwan and wont check i.e. lm_net_wan_static
... Hopefully in this case it works anyway because it pings on device eth0.2
as it takes ifname from the existing interface wan that use the same device as lm_new_wan_static

As a proposal, could have sense instead to define an overwriteable array of main wan interfaces? And let both watchping and babeld-auto-gw-mode check this list to do their stuff?
For example in uci:

uci set lime-defaults.main_wan_interfaces='wan wan6 client-wwan lm_net_wan_static lm_net_wan6_static'

allowing so, to do this in my case:

uci set lime-node.main_wan_interfaces='lm_net_eth0_2_static'

babeld-auto-gw-mode with or without ubus doesn't matter at this point, but i wonder:

• what would be the best way to handle metrics codes ('7' '84831') for multiple wan ifaces in babeld watchping's scripts?
• should it set proto 7 all default routes, using maybe different metrics starting from 10,
  or should it only set proto 7 on the best (as it is done in the scripts below that check only first default route with metric 0)?

Both watchping and babeld-auto-gw-mode should in this case create the dir or copy the scripts to /etc/watchping/$interface-$reason.d/ taking the $interface from this list

Here the example of babel watchping's hooks without ubus that check route and device from iproute:

/etc/watchping/wan-fail.d/babeld-gw

#!/usr/bin/lua
--! Copyright (C) 2021 Santiago Piccinini 
--!
--! This is free software, licensed under the GNU Affero General Public License v3.
local utils = require "lime.utils"
local NONWORKING_ROUTE_METRIC = 84831
local wan4_dev = utils.unsafe_shell("ip r s default metric 0 | cut -d ' ' -f 5"):gsub("\n","")
if wan4_dev ~= '' then

--! Do our best to select only the "original" default route installed. Using grep because

--! using the dev argument removes the dev part of the ip route output.

local route = utils.unsafe_shell("ip r s default metric 0 | grep " .. wan4_dev):gsub("\n","")
--! replace the default route with one that has metric NONWORKING_ROUTE_METRIC
if route ~= '' then
    os.execute("ip r add " .. route .. " metric " .. tonumber(NONWORKING_ROUTE_METRIC))
    os.execute("ip r del " .. route)
end

--! remove the babel redistributable route
os.execute("ip r del default proto 7")

end

/etc/watchping/wan-ok.d/babeld-gw

#!/usr/bin/lua
--! Copyright (C) 2021 Santiago Piccinini 
--!
--! This is free software, licensed under the GNU Affero General Public License v3.
local utils = require "lime.utils"
local wan4_dev_not = utils.unsafe_shell("ip r s default metric 84831 | cut -d ' ' -f 5"):gsub("\n","")
if wan4_dev_not ~= '' then

--! change the default route from the nonworking metric value to the working metric value

local nonworking_route = utils.unsafe_shell("ip r s default metric 84831 | grep " .. wan4_dev_not):gsub("\n","")

if nonworking_route ~= '' then

os.execute("ip r add " .. nonworking_route .. " metric 0")

os.execute("ip r del " .. nonworking_route .. " metric 84831")

end

end
local wan4_dev = utils.unsafe_shell("ip r s default metric 0"):gsub("\n","")
if wan4_dev ~= '' then

--! install a route with proto value 7 that will be redistributed by babeld

local r = utils.unsafe_shell("echo " .. wan4_dev .. " | sed 's|\(.\) proto.|ip r a \1 proto 7 metric 10|'"):gsub("\n","")

os.execute(r)

end

[ilario]

An alternative could be to add the IP and gateway IP as options of the wan proto.

Either something like this:

config net lm_hwd_openwrt_wan
	option autogenerated 'false'
	option linux_name 'wan'
	list protocols 'wan:192.168.1.2/24:192.168.1.1'

or something like this:

config net lm_hwd_openwrt_wan
	option autogenerated 'false'
	option linux_name 'wan'
	list protocols 'wan'
	option wan_static_ipv4 '192.168.1.2/24'
	option wan_static_gateway_ipv4 '192.168.1.1'

These IPs will then be taken and used for setting the static configuration here: https://github.com/libremesh/lime-packages/blob/master/packages/lime-proto-wan/files/usr/lib/lua/lime/proto/wan.lua#L16

We can take some code from the static proto:
https://github.com/libremesh/lime-packages/blob/master/packages/lime-system/files/usr/lib/lua/lime/proto/static.lua