--- /dev/null
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2021 Nick Hainke <vincent@systemli.org>
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=naywatch
+PKG_VERSION:=1
+PKG_RELEASE:=$(AUTORELEASE)
+
+PKG_MAINTAINER:=Nick Hainke <vincent@systemli.org>
+PKG_LICENSE:=GPL-2.0-only
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/naywatch
+ SECTION:=utils
+ CATEGORY:=Utilities
+ TITLE:=Watchdog for IPv6 links
+ PKGARCH:=all
+ DEPENDS:=@IPV6 +owipcalc
+endef
+
+define Package/naywatch/description
+Reboots or triggers watchdog if no link local neighbor is available.
+endef
+
+define Package/naywatch/conffiles
+/etc/config/naywatch
+endef
+
+define Build/Compile
+endef
+
+define Package/naywatch/install
+ $(INSTALL_DIR) $(1)/etc/init.d
+ $(INSTALL_BIN) ./files/naywatch.init $(1)/etc/init.d/naywatch
+ $(INSTALL_DIR) $(1)/usr/bin
+ $(INSTALL_BIN) ./files/naywatch.sh $(1)/usr/bin/naywatch
+ $(INSTALL_DIR) $(1)/etc/config
+ $(INSTALL_DATA) ./files/naywatch.config $(1)/etc/config/naywatch
+endef
+
+$(eval $(call BuildPackage,naywatch))
--- /dev/null
+config naywatch general
+ option check_interval '50'
+ option watchdog_timeout '60'
+ option use_watchdog '1'
+ option save_logs '1'
+ list interface 'lan'
+ list interface 'wan'
+ list save_cmd 'dmesg'
--- /dev/null
+#!/bin/sh /etc/rc.common
+
+USE_PROCD=1
+START=95
+STOP=01
+
+log() {
+ local msg="$1"
+ logger -t naywatch "$msg"
+}
+
+wait_for_network()
+{
+ ubus -t 15 wait_for network.interface.$1 2>/dev/null
+}
+
+boot()
+{
+ local _interfaces
+ config_load naywatch
+ config_get _interfaces general interface
+
+ for interface in $_interfaces; do
+ wait_for_network interface
+ done
+
+ rc_procd start_service
+}
+
+start_service() {
+ procd_open_instance
+
+ config_load naywatch
+ local _check_interval
+ local _watchdog_timeout
+ local _use_watchdog
+ local _save_logs
+ local _interfaces
+
+ config_get _check_interval general "check_interval"
+ config_get _watchdog_timeout general "watchdog_timeout"
+ config_get _use_watchdog general "use_watchdog"
+ config_get _save_logs general "save_logs"
+ config_get _interfaces general "interface"
+
+ procd_set_param command /usr/bin/naywatch "$_check_interval" "$_watchdog_timeout" "$_use_watchdog" "$_save_logs" "$_interfaces"
+
+ procd_set_param respawn 3600 15 0
+
+ procd_set_param stdout 1
+ procd_set_param stderr 1
+
+ procd_close_instance
+}
+
+stop_service() {
+ exec 3>&- # close file again
+ sync && wait
+}
+
+service_stopped() {
+ log "Naywatch Stopped!"
+ log "Handover Watchdog to procd again:"
+ ubus call system watchdog '{"magicclose":true,"stop":false}' > /dev/null
+}
--- /dev/null
+#!/bin/sh
+
+. /lib/functions.sh
+. /lib/functions/network.sh
+
+CHECK_INTERVAL=$1
+shift
+WATCHDOG_TIMEOUT=$1
+shift
+USE_WATCHDOG=$1
+shift
+SAVE_LOGS=$1
+shift
+INTERFACES="$*"
+
+ACTIVE=0
+
+log() {
+ local msg="$1"
+ logger -t naywatch "$msg"
+}
+
+write_logs() {
+ save_log() {
+ eval $1 > /root/$(date +%s)-"$1".log
+ }
+ config_load naywatch
+ config_list_foreach general save_cmd save_log
+ sync
+}
+
+neighbors_available() {
+ local phy
+
+ for interface in $INTERFACES; do
+ network_get_physdev phy $interface > /dev/null 2>&1
+ linklocal=$(ip -6 a list dev $phy | grep "scope link" | awk '{print $2}' | sed 's/\/64//') 2> /dev/null
+ ips=$(ping ff02::1%$phy -w5 -W5 -c2 | awk '/from/{print($4)}' | sed 's/.$//') 2> /dev/null
+ for ip in $ips; do
+ if [ $ip != $linklocal ] && [ $(owipcalc $ip linklocal) -eq 1 ]; then
+ echo 1
+ return 0
+ fi
+ done
+ done
+
+ echo 0
+}
+
+activate_watchdog() {
+ # disable openwrt instrumentation:
+ ubus call system watchdog '{"magicclose":true,"stop":true,"timeout":'${WATCHDOG_TIMEOUT}'}' > /dev/null
+ exec 3>/dev/watchdog
+}
+
+reboot_now() {
+ # copied from watch-cat
+ reboot &
+
+ [ "$1" -ge 1 ] && {
+ sleep "$1"
+ echo 1 >/proc/sys/kernel/sysrq
+ echo b >/proc/sysrq-trigger
+ }
+}
+
+no_neighbors() {
+ log "No Neighbors Available!"
+
+ if [ $ACTIVE -eq 0 ]; then
+ return 0
+ fi
+
+ if [ $SAVE_LOGS ]; then
+ log "Saving Logs!"
+ write_logs
+ fi
+
+ if [ $USE_WATCHDOG -eq 0 ]; then
+ reboot_now
+ fi
+}
+
+log "Naywatch Started!"
+
+neighbors() {
+ ACTIVE=1
+ if [ $USE_WATCHDOG ]; then
+ echo 1 >&3
+ fi
+}
+
+not_active() {
+ if [ $USE_WATCHDOG ]; then
+ echo 1 >&3
+ fi
+}
+
+if [ $USE_WATCHDOG ]; then
+ activate_watchdog
+fi
+
+while [ 1 ]; do
+ # first sleep
+ sleep $CHECK_INTERVAL
+
+ has_neighbor=$(neighbors_available)
+ if [ $has_neighbor -eq 0 ] && [ $ACTIVE -eq 1 ]; then
+ no_neighbors
+ elif [ $has_neighbor -eq 1 ]; then
+ neighbors
+ else
+ not_active
+ fi
+done
+
+exit 0