From 1398716680c74159393312137e3bc9bbeaa032f9 Mon Sep 17 00:00:00 2001
From: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Date: Mon, 4 Nov 2019 20:44:41 +0100
Subject: [PATCH] base-files: don't store label MAC address in uci system
 config

If set, label MAC address is available from one of two sources,
device tree or board.json. So far, the function get_mac_label
was meant for retrieving the address, while an option in uci
system config was specified only for case 2 (board.json).

The uci config option has several drawbacks:
- it is only used for a fraction of devices (those not in DT)
- label MAC address is a device property, while config implies
  user interaction
- label_macaddr option will only be set if /etc/config/system
  does not exist (i.e. only for new installations)

Thus, this patch changes the behavior of get_mac_label:
Instead of writing the value in board.json to uci system config
and reading from this location afterwards, get_mac_label now
extracts data from board.json directly. The uci config option
won't be used anymore.
In addition, two utility functions for extraction only from DT
or from board.json are introduced.

Since this is only changing the access to the label MAC address, it
won't interfere with the addresses stored in the code base so far.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
---
 package/base-files/files/bin/config_generate  |  5 ---
 .../base-files/files/lib/functions/system.sh  | 35 +++++++++++++++++--
 2 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/package/base-files/files/bin/config_generate b/package/base-files/files/bin/config_generate
index a72702492f..ea04d17d0b 100755
--- a/package/base-files/files/bin/config_generate
+++ b/package/base-files/files/bin/config_generate
@@ -257,11 +257,6 @@ generate_static_system() {
 				uci -q set "system.@system[-1].hostname=$hostname"
 			fi
 
-			local label_macaddr
-			if json_get_var label_macaddr label_macaddr; then
-				uci -q set "system.@system[-1].label_macaddr=$label_macaddr"
-			fi
-
 			if json_is_a ntpserver array; then
 				local keys key
 				json_get_keys keys ntpserver
diff --git a/package/base-files/files/lib/functions/system.sh b/package/base-files/files/lib/functions/system.sh
index 6ff1c68577..1b82046f92 100755
--- a/package/base-files/files/lib/functions/system.sh
+++ b/package/base-files/files/lib/functions/system.sh
@@ -1,5 +1,7 @@
 # Copyright (C) 2006-2013 OpenWrt.org
 
+. /usr/share/libubox/jshn.sh
+
 get_mac_binary() {
 	local path="$1"
 	local offset="$2"
@@ -12,14 +14,41 @@ get_mac_binary() {
 	hexdump -v -n 6 -s $offset -e '5/1 "%02x:" 1/1 "%02x"' $path 2>/dev/null
 }
 
-get_mac_label() {
+get_mac_label_dt() {
 	local basepath="/proc/device-tree"
 	local macdevice="$(cat "$basepath/aliases/label-mac-device" 2>/dev/null)"
 	local macaddr
 
-	[ -n "$macdevice" ] && macaddr=$(get_mac_binary "$basepath/$macdevice/mac-address" 0 2>/dev/null)
+	[ -n "$macdevice" ] || return
+
+	macaddr=$(get_mac_binary "$basepath/$macdevice/mac-address" 0 2>/dev/null)
 	[ -n "$macaddr" ] || macaddr=$(get_mac_binary "$basepath/$macdevice/local-mac-address" 0 2>/dev/null)
-	[ -n "$macaddr" ] || macaddr=$(uci -q get system.@system[0].label_macaddr)
+
+	echo $macaddr
+}
+
+get_mac_label_json() {
+	local cfg="/etc/board.json"
+	local macaddr
+
+	[ -s "$cfg" ] || return
+
+	json_init
+	json_load "$(cat $cfg)"
+	if json_is_a system object; then
+		json_select system
+			json_get_var macaddr label_macaddr
+		json_select ..
+	fi
+
+	echo $macaddr
+}
+
+get_mac_label() {
+	local macaddr=$(get_mac_label_dt)
+
+	[ -n "$macaddr" ] || macaddr=$(get_mac_label_json)
+
 	echo $macaddr
 }