gluon-core: rewrite MAC-address generation logic

This rewrites the MAC address generation logic to distinguish between
MAC addresses assigned to a wireless interface or virtual / wired
interfaces.

Each radio is now assigned a range of SSIDs, allowing for up to 8 SSIDs
per radio. Previosuly, there were 8 MAC addresses total for the entire
device.

To keep compatibility on already deployed nodes, MAC addresses for wired
/ virtual interfaces stay unchanged.

This change is required to support nodes with more than 2 radios.
It also allows us to increase the number of VAPs per radio.

docs/dev/mac_addresses.rst

@@ -6,13 +6,19 @@ Many devices don't have enough unique MAC addresses assigned by the vendor
 mesh-wide).
 
 Gluon tries to solve this issue by using a hash of the primary MAC address as a
-45 bit MAC address prefix. The resulting 8 addresses are used as follows:
+45 bit MAC address prefix per radio. One additional prefix is dedicated to wired
+interfaces as well as the mesh-protocol.
 
-* 0: client0; WAN
-* 1: mesh0
-* 2: owe0
-* 3: wan_radio0 (private WLAN); batman-adv primary address
-* 4: client1; LAN
-* 5: mesh1
-* 6: owe1
-* 7: wan_radio1 (private WLAN); mesh VPN
+The remaining 3 bits are assigned to the following interfaces / VAPs:
+
+IDs for non-radio interfaces defined so far:
+* 0: WAN
+* 3: batman-adv primary address
+* 4: LAN
+* 7: mesh VPN
+
+IDs for radio interfaces defined so far:
+* 0: client
+* 1: mesh
+* 2: owe
+* 3: wan_radio (private WLAN)

package/gluon-core/files/lib/netifd/proto/gluon_wired.sh

@@ -41,7 +41,7 @@ proto_gluon_wired_setup() {
 
                 json_init
                 json_add_string name "$meshif"
-                [ -n "$index" ] && json_add_string macaddr "$(lua -e "print(require('gluon.util').generate_mac($index))")"
+                [ -n "$index" ] && json_add_string macaddr "$(lua -e "print(require('gluon.util').generate_mac(0, $index))")"
                 json_add_string proto 'vxlan6'
                 json_add_string tunlink "$config"
                 json_add_string ip6addr "$(interface_linklocal "$ifname")"

package/gluon-core/luasrc/usr/lib/lua/gluon/util.lua

@@ -176,18 +176,23 @@ local function get_addresses(radio)
 end
 
 -- Generates a (hopefully) unique MAC address
--- The parameter defines the ID to add to the MAC address
+-- The range parameter identifies the range the MAC address belongs to
+-- Range 0 is reserved for MAC addresses not assigned to a radio
+-- Wireless PHYs are assigned starting at range 1
+-- The i parameter defines the ID to add to the MAC address
 --
--- IDs defined so far:
--- 0: client0; WAN
--- 1: mesh0
--- 2: owe0
--- 3: wan_radio0 (private WLAN); batman-adv primary address
--- 4: client1; LAN
--- 5: mesh1
--- 6: owe1
--- 7: wan_radio1 (private WLAN); mesh VPN
-function M.generate_mac(i)
+-- IDs for non-radio interfaces defined so far:
+-- 0: WAN
+-- 3: batman-adv primary address
+-- 4: LAN
+-- 7: mesh VPN
+--
+-- IDs for radio interfaces defined so far:
+-- 0: client
+-- 1: mesh
+-- 2: owe
+-- 3: wan_radio (private WLAN)
+function M.generate_mac(range, i)
 	if i > 7 or i < 0 then return nil end -- max allowed id (0b111)
 
 	local hashed = string.sub(hash.md5(sysconfig.primary_mac), 0, 12)
@@ -199,6 +204,13 @@ function M.generate_mac(i)
 	m1 = bit.bor(m1, 0x02)  -- set locally administered bit
 	m1 = bit.band(m1, 0xFE) -- unset the multicast bit
 
+	m5 = tonumber(m5, 16)
+	m5 = m5 + range
+
+	if m5 > 255 then
+		m5 = m5 - 256
+	end
+
 	-- It's necessary that the first 45 bits of the MAC address don't
 	-- vary on a single hardware interface, since some chips are using
 	-- a hardware MAC filter. (e.g 'rt305x')
@@ -206,7 +218,7 @@ function M.generate_mac(i)
 	m6 = bit.band(m6, 0xF8) -- zero the last three bits (space needed for counting)
 	m6 = m6 + i                   -- add virtual interface id
 
-	return string.format('%02x:%s:%s:%s:%s:%02x', m1, m2, m3, m4, m5, m6)
+	return string.format('%02x:%s:%s:%s:%02x:%02x', m1, m2, m3, m4, m5, m6)
 end
 
 local function get_wlan_mac_from_driver(radio, vif)
@@ -237,7 +249,7 @@ function M.get_wlan_mac(_, radio, index, vif)
 		return addr
 	end
 
-	return M.generate_mac(4*(index-1) + (vif-1))
+	return M.generate_mac(index, (vif-1))
 end
 
 -- Iterate over all radios defined in UCI calling

package/gluon-mesh-batman-adv/files/lib/netifd/proto/gluon_bat0.sh

@@ -62,7 +62,7 @@ proto_gluon_bat0_setup() {
 	esac
 
 
-	local primary0_mac="$(lua -e 'print(require("gluon.util").generate_mac(3))')"
+	local primary0_mac="$(lua -e 'print(require("gluon.util").generate_mac(0, 3))')"
 
 	ip link add primary0 type dummy
 	echo 1 > /proc/sys/net/ipv6/conf/primary0/disable_ipv6

package/gluon-mesh-batman-adv/luasrc/lib/gluon/upgrade/330-gluon-mesh-batman-adv-mac-addresses

@@ -5,6 +5,6 @@ local uci = require('simple-uci').cursor()
 
 
 -- fix up potentially duplicate MAC addresses (for meshing)
-uci:set('network', 'wan', 'macaddr', util.generate_mac(0))
-uci:set('network', 'mesh_lan', 'macaddr', util.generate_mac(4))
+uci:set('network', 'wan', 'macaddr', util.generate_mac(0, 0))
+uci:set('network', 'mesh_lan', 'macaddr', util.generate_mac(0, 4))
 uci:save('network')

package/gluon-mesh-vpn-core/luasrc/lib/gluon/upgrade/500-mesh-vpn

@@ -13,7 +13,7 @@ uci:section('network', 'interface', 'mesh_vpn', {
 	proto = 'gluon_mesh',
 	transitive = true,
 	fixed_mtu = true,
-	macaddr = util.generate_mac(7),
+	macaddr = util.generate_mac(0, 7),
 	mtu = site.mesh_vpn.mtu(),
 })