#!/bin/bash
LANG=C

PING_COUNT=2
CHECK_INTERVAL_SEC=120
FORCE_RECONNECT_PING_NG_COUNT=2
FORCE_REBOOT_PING_NG_COUNT=$(( $FORCE_RECONNECT_PING_NG_COUNT+2 ))
CONFIG_FILE_EXT=_connection-recover.conf
CONFIG_FILE_DIR=/etc/connection-recover/
SYMLINK_CONF_FILE=/etc/ModemManager/symlink.conf
NMCLI_UP_TIMEOUT_SEC=150
RESTART_SIM_NOT_FOUND_COUNT=2
REGEX_GSM_TTY="^gsm-tty"
CONNECTING_COUNT_FOR_RECONNECT=3

active_connection_exist() {
	nmcli -f NAME connection | sed -e 's/ *$//' | grep -x -q ${CONNECTION}
	if [ $? -eq 0 ]; then
		return 0
	fi
	return 1
}

check_symlink_conf_line() {
	while read line
	do
		line="`echo ${line} | sed 's/ //g'`"
		if [ "${line}" = ${SYMLINK_MM_PARAM} ]; then
			return 0
		fi
	done < $SYMLINK_CONF_FILE
	return 1
}

check_use_symlink_device() {
	if [ ! -L /dev/${SYMLINKDEVICE} ]; then
		return 1
	fi

	if [ ! -e "$SYMLINK_CONF_FILE" ]; then
		return 1
	fi

	if [ -z "$SYMLINKDEVICE" ]; then
		return 1
	fi

	if [ -z "$SYMLINK_MM_PARAM" ]; then
		return 1
	fi

	check_symlink_conf_line
	return $?
}

get_connection_status() {
	nmcli -f DEVICE,STATE device | grep "$DEVICE"
}

reconnect() {
	logger -t connection-recover "$DEVICE reconnect start... "
	nmcli connection down ${CONNECTION} > /dev/null 2>&1
	sleep 5
	timeout -sKILL ${NMCLI_UP_TIMEOUT_SEC} nmcli connection up ${CONNECTION} > /dev/null 2>&1
	result=$?
	if [ ${result} -eq 0 ]; then
		logger -t connection-recover "$DEVICE reconnect success"
	else
		logger -t connection-recover "$DEVICE reconnect fail: ${result}"
		return -1
	fi
	return 0
}

check_route() {
	ip route get ${PING_DEST_IP} | grep ${NETWORK_IF} > /dev/null 2>&1
}

is_connect() {
	ping -s 1 -c ${PING_COUNT} -w 10 -I ${NETWORK_IF} ${PING_DEST_IP} > /dev/null 2>&1
	if [ $? -eq 0 ]; then
		return 0
	else
		logger -t connection-recover "$DEVICE ping fail"
	fi
	return 1
}

clear_config() {
	PRODUCT_NAME=""
	PING_DEST_IP=""
	DEVICE=""
	TYPE=""
	NETWORK_IF=""
	SYMLINKDEVICE=""
	SYMLINK_MM_PARAM=""
	WWAN_FORCE_RESTART_COUNT=""
	REBOOT_IF_SIM_NOT_FOUND=""
}

read_config_file() {
	. ${CONFIG_FILE}

	if [ ! -n "$PRODUCT_NAME" ]; then
		logger -t connection-recover "$1 is PRODUCT_NAME not set"
		return 1
	fi
	if [ ! -n "$PING_DEST_IP" ]; then
		logger -t connection-recover "$1 is PING_DEST_IP not set"
		return 1
	fi
	if [ ! -n "$DEVICE" ]; then
		logger -t connection-recover "$1 is DEVICE not set"
		return 1
	fi
	if [ ! -n "$TYPE" ]; then
		logger -t connection-recover "$1 is TYPE not set"
		return 1
	fi
	if [ ! -n "$NETWORK_IF" ]; then
		logger -t connection-recover "$1 is NETWORK_IF not set"
		return 1
	fi
	if [ ! -n "$FORCE_REBOOT" ]; then
		logger -t connection-recover "$1 is FORCE_REBOOT not set"
		return 1
	fi

	OLD_IFS=$IFS
	IFS=","
	for CHECK_PRODUCT in $PRODUCT_NAME; do
		grep ${CHECK_PRODUCT} /proc/device-tree/model -q -w
		if [ $? -eq 0 ]; then
			IFS=$OLD_IFS
			return 0
		fi
	done
	IFS=$OLD_IFS

	return 1
}

load_config() {
	OLD_IFS=$IFS
	IFS="
"
	for CONFIG_FILE in `find ${CONFIG_FILE_DIR} -name "*${CONFIG_FILE_EXT}"`; do
		clear_config
		if ! read_config_file; then
			continue
		else
			IFS=$OLD_IFS
			return	
		fi
	done

	IFS=$OLD_IFS
	logger -t connection-recover "error: config file is not found"
	exit 1
}

load_config

PING_NG_COUNT=0
SIM_NOT_FOUND_COUNT=0
WWAN_RESTART_COUNT=0
CONNECTING_COUNT=0

if [ -z "$WWAN_FORCE_RESTART_COUNT" ]; then
	WWAN_FORCE_RESTART_COUNT=1
fi

DEFAULT_DEVICE=${DEVICE}

while true; do

	sleep ${CHECK_INTERVAL_SEC}

	check_use_symlink_device
	if [ $? -eq 0 ]; then
		DEVICE=${SYMLINKDEVICE}
	else
		DEVICE=${DEFAULT_DEVICE}
	fi

	CONNECTION=$(basename "$CONFIG_FILE" "$CONFIG_FILE_EXT")
	if [[ -z "$CONNECTION" || $CONNECTION =~ $REGEX_GSM_TTY ]]; then
		CONNECTION="${TYPE}-${DEVICE}"
	fi

	if [ -z "$CONNECTION" ]; then
		continue
	fi

	active_connection_exist
	if [ $? -eq 0 ]; then

		PING_STATUS=1

		STATUS=`get_connection_status`
		case ${STATUS} in
		*disconnected*|*failed*|*unknown*|"*connection failed*")
			SIM_NOT_FOUND_COUNT=0
			CONNECTING_COUNT=0
			reconnect
			if [ $? -eq 0 ]; then
				continue
			fi ;;
		*connected*)
			SIM_NOT_FOUND_COUNT=0
			CONNECTING_COUNT=0
			is_connect
			PING_STATUS=$?
			if [ $PING_STATUS -ne 0 ]; then
				# if reboot or restart wwan, do not reconnect
				PING_NG_COUNT_TMP=$(( $PING_NG_COUNT+1 ))
				if [ $PING_NG_COUNT_TMP -lt $FORCE_RECONNECT_PING_NG_COUNT ]; then
					reconnect
				elif [ "$FORCE_REBOOT" = "TRUE" ]; then
					if [ $PING_NG_COUNT_TMP -lt $FORCE_REBOOT_PING_NG_COUNT ]; then
						reconnect
					fi
				fi
			else
				WWAN_RESTART_COUNT=0
			fi ;;
		*connecting*)
			SIM_NOT_FOUND_COUNT=0
			CONNECTING_COUNT=$((CONNECTING_COUNT + 1))
			if [ $CONNECTING_COUNT -ge $CONNECTING_COUNT_FOR_RECONNECT ]; then
				logger -t connection-recover "reconnect because connecting status occurred twice"
                                CONNECTING_COUNT=0
				reconnect
			fi
			continue ;;
		*deactivating*|*unmanaged*)
			SIM_NOT_FOUND_COUNT=0
			CONNECTING_COUNT=0
			continue ;;
		*unavailable*|*)
			CONNECTING_COUNT=0
			if [ "$REBOOT_IF_SIM_NOT_FOUND" != "TRUE" ] ; then
				continue
			fi
			SIM_NOT_FOUND_COUNT=$((SIM_NOT_FOUND_COUNT + 1))
			logger -t connection-recover "sim not found. status: ${STATUS}"
			if [ $SIM_NOT_FOUND_COUNT -ge $RESTART_SIM_NOT_FOUND_COUNT ] ; then
				logger -t connection-recover "exec system reboot cause sim not found"
				reboot
			fi
		esac

		if [ $PING_STATUS -ne 0 ]; then
			PING_NG_COUNT=$(( $PING_NG_COUNT+1 ))
			if [ "$FORCE_REBOOT" = "TRUE" ]; then
				if [ $PING_NG_COUNT -ge $FORCE_REBOOT_PING_NG_COUNT ]; then
					logger -t connection-recover "exec system reboot"
					reboot
				fi
			fi
			if [ $PING_NG_COUNT -ge $FORCE_RECONNECT_PING_NG_COUNT ]; then
				WWAN_RESTART_COUNT=$((WWAN_RESTART_COUNT+1))
				if [ $WWAN_RESTART_COUNT -ge $WWAN_FORCE_RESTART_COUNT ]; then
					logger -t connection-recover "exec wwan-force-restart"
					wwan-force-restart "$CONNECTION"
					WWAN_RESTART_COUNT=0
				else
					logger -t connection-recover "exec wwan-restart"
					wwan-force-restart "$CONNECTION" airplane
				fi
			fi
		else
			PING_NG_COUNT=0
		fi

	fi

done