From f444114ea65bb0dd179045fd69e1cee39a2d0439 Mon Sep 17 00:00:00 2001
From: johndi3 <gayhub@fastmail.com>
Date: Sat, 27 Jan 2024 09:00:04 +0800
Subject: [PATCH] enable eth0 by default with highest priority, monitor ethenet
 state changes

---
 general/overlay/etc/init.d/S40network         |  5 ++--
 general/overlay/usr/sbin/interface_monitor.sh | 25 +++++++++++++++++++
 .../overlay/usr/share/udhcpc/default.script   | 12 +++++++--
 3 files changed, 38 insertions(+), 4 deletions(-)
 create mode 100755 general/overlay/usr/sbin/interface_monitor.sh

diff --git a/general/overlay/etc/init.d/S40network b/general/overlay/etc/init.d/S40network
index 1da04b7c..34cac531 100755
--- a/general/overlay/etc/init.d/S40network
+++ b/general/overlay/etc/init.d/S40network
@@ -11,7 +11,6 @@ set_wireless() {
 	elif $path/modem "$dev"; then
 		ifup usb0
 	fi
-	[ -e /sys/class/net/eth0 ] && ifconfig eth0 "${net:-192.168.2.10}"
 }
 
 case "$1" in
@@ -20,8 +19,10 @@ case "$1" in
 		ifup lo
 		if [ -n "$dev" ]; then
 			set_wireless
-		else
+		fi
+		if [ -e /sys/class/net/eth0 ]; then
 			ifup eth0
+			/usr/sbin/interface_monitor.sh eth0 &
 		fi
 		;;
 
diff --git a/general/overlay/usr/sbin/interface_monitor.sh b/general/overlay/usr/sbin/interface_monitor.sh
new file mode 100755
index 00000000..0ff582b9
--- /dev/null
+++ b/general/overlay/usr/sbin/interface_monitor.sh
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+monitor_interface () {
+        local fileoperstate=/sys/class/net/"$1"/operstate
+        local state oldstate=$(cat "$fileoperstate")
+
+        while sleep 2; do
+                state=$(cat "$fileoperstate")
+                if [ "$oldstate" = "$state" ]; then
+                        continue
+                fi
+                oldstate="$state"
+                echo "interface $1 is $state"
+                case "$state" in
+                        down | lowerlayerdown)
+                                kill -12 `cat /var/run/udhcpc.$1.pid`
+                                ;;
+                        up)
+                        kill -10 `cat /var/run/udhcpc.$1.pid`
+                                ;;
+                        esac
+        done
+}
+
+monitor_interface "$1"
diff --git a/general/overlay/usr/share/udhcpc/default.script b/general/overlay/usr/share/udhcpc/default.script
index 925137f9..238655e4 100755
--- a/general/overlay/usr/share/udhcpc/default.script
+++ b/general/overlay/usr/share/udhcpc/default.script
@@ -54,7 +54,8 @@ case "$1" in
 		if [ -x /usr/sbin/avahi-autoipd ]; then
 			/usr/sbin/avahi-autoipd -c $interface || /usr/sbin/avahi-autoipd -wD $interface --no-chroot
 		fi
-		/sbin/ifconfig $interface $(fw_printenv -n ipaddr || echo -n 192.168.1.10) netmask $(fw_printenv -n netmask || echo -n 255.255.255.0) up
+		#/sbin/ifconfig $interface $(fw_printenv -n ipaddr || echo -n 192.168.1.10) netmask $(fw_printenv -n netmask || echo -n 255.255.255.0) up
+		/sbin/ifconfig $interface up
 		;;
 
 	renew|bound)
@@ -73,7 +74,14 @@ case "$1" in
 			done
 
 			for i in $router ; do
-				route add default gw $i dev $interface
+				if [ $interface = "eth0" ]; then
+					metric=0
+				elif [ $interface = "wlan0" ]; then
+					metric=10
+				else
+					metric=20
+				fi
+				route add default gw $i dev $interface metric $metric
 			done
 		fi