#!/bin/sh

. ${STREAMBOOST_CFGDIR:-/etc/appflow}/rc.appflow
. ${STREAMBOOST_CFGDIR:-/etc/appflow}/classids.sh

# Note: EXTRA_COMMANDS isn't actually used by the rc.appflow environment, but
# it's defined here in the hopes that one day it will be.  At that time,
# the redefinition of action() and usage() in this file should be deleted.
EXTRA_COMMANDS="start_qdiscs stop_qdiscs setup_iptables teardown_iptables"
EXTRA_HELP="        start_qdiscs	create root qdisc structure
        stop_qdiscs	delete root qdisc structure
        setup_iptables	insert iptables rules
        teardown_iptables	delete iptables rules"

#
# Environment config
#
NAME="qdiscman"
DISPLAY_NAME=${NAME}

# path to binary
BINARY="${BINDIR}/${NAME}"

# path to pid file
PIDFILE="${RUNDIR}/${NAME}.pid"

# Redis server port
REDIS_PORT=6379

# source the setup_iface, setup_iptables, and teardown_iptables functions,
# switched by whether or not we're enabled for NSS mode.  to be enabled
# for NSS mode, the kmod-qca-nss-qdisc package must be installed and the
# nss_qdisc variable in streamboost.user.conf must be 'yes'.
if nss_qdisc_is_installed; then
	# we can potentially use NSS QDiscs, so see if we're configured for it.
	# the user config file contains the nss_qdisc setting
	. $STREAMBOOST_USER_CFG
	# test the nss_qdisc value to see if we're in NSS mode
	if [ "${nss_qdisc}" = "yes" ]; then
		. ${STREAMBOOST_CFGDIR:-/etc/appflow}/qdiscman-nss.sh
	else
		. ${STREAMBOOST_CFGDIR:-/etc/appflow}/qdiscman.sh
	fi
else
	. ${STREAMBOOST_CFGDIR:-/etc/appflow}/qdiscman.sh
fi

[ -f /etc/dhcp.guest.conf ] && . /etc/dhcp.guest.conf

# Format the command line parameters
CMDLINE_OPTS="\
--daemon \
--run-dir=${RUNDIR} \
--pid-file=${PIDFILE} \
--redis-port=${REDIS_PORT} \
--redis-stat-prefix=flowdb:flows: \
--ifname-up=${WAN_IFACE} \
--ifname-down=${LAN_IFACE} \
${EXTRA_CMD_ARGS} \
"

#
# Functions
#
sb_get_max_zone_id() {
	redis-cli get "settings:max_zone_id"
}

# prints 0 if a zone with the given ID is configured in redis, else 1
# $1: zone id
sb_zone_is_configured() {
	local zone=$1
	if [ $(redis-cli exists "settings:zone:${zone}") = "1" ] &&
	   [ $(redis-cli hexists "settings:zone:${zone}" "weight:up") = "1" ] &&
	   [ $(redis-cli hexists "settings:zone:${zone}" "weight:down") = "1" ]; then
		echo 0
	else
		echo 1
	fi
}

# echos the number of configured zones.  a zone is considered "configured"
# if it has a hash entry in settings:zone:<id> where id is less than
# settings:max_zone_id
sb_get_zone_count() {
	local maxzoneid=$(sb_get_max_zone_id)
	local zone=0
	local count=0

	if [ -n "${maxzoneid}" ]; then
		while [ "${zone}" -le "${maxzoneid}" ]; do
			if [ $(sb_zone_is_configured ${zone}) = "0" ]; then
				let count=count+1
			fi
			let zone=zone+1
		done
	fi

	echo ${count}
}

# returns a zone config item from redis
# $1: dev (e.g., eth0, br-lan, etc.)
# $2: zone (integer zone identifier)
# $3: key (e.g., bw, weight)
# $4: default (returned if key doesn't exist)
sb_get_zone_config() {
	local dev=$1
	local zone=$2
	local key=$3
	local default=$4

	if [ "${dev}" = "${WAN_IFACE}" ]; then
		redis-cli hget settings:zone:${zone} ${key}:up
	elif [ "${dev}" = "${LAN_IFACE}" ]; then
		redis-cli hget settings:zone:${zone} ${key}:down
	else
		echo ${default}
		echo "error: ${dev} is not a supported interface" 1>&2
	fi
}

# returns the "bw" key from the zone config for the given interface zone
# $1: dev
# $2: zone
sb_get_zone_rate() {
	sb_get_zone_config $1 $2 bw
}

# returns the "weight" key from the zone config for the given interface zone
# $1: dev
# $2: zone
sb_get_zone_weight() {
	sb_get_zone_config $1 $2 weight 10000
}

# generates a hex value in the CLASSID_ZONE_BASE range that can be
# used as a classid or a qdisc handle
# $1: zone id
sb_gen_zone_classid() {
	printf "%x" $((0x${CLASSID_ZONE_BASE} + ${1}))
}

# generates a hex value in the CLASSID_ZONE_TBL_BASE range that can be
# used as a classid or a qdisc handle for NSS-based zone
# $1: zone id
sb_gen_zone_tbl_classid() {
	printf "%x" $((0x${CLASSID_ZONE_TBL_BASE} + ${1}))
}

# generates a hex value in the CLASSID_ZONE_BG_BASE range that can be
# used as a classid or a qdisc handle for NSS-based zone background qdisc
# $1: zone id
sb_gen_zone_bg_classid() {
	printf "%x" $((0x${CLASSID_ZONE_BG_BASE} + ${1}))
}

# generates a hex value in the CLASSID_ZONE_CL_BASE range that can be
# used as a classid or a qdisc handle for NSS-based zone classified qdisc
# $1: zone id
sb_gen_zone_cl_classid() {
	printf "%x" $((0x${CLASSID_ZONE_CL_BASE} + ${1}))
}

# $1: dev
# $2: parent
# $3: handle
# $4: qdisc type (default = fq_codel)
# $5: extra opts
add_interactive_qdisc() {
	tc qdisc add dev $1 parent $2 handle $3 \
		${4:-fq_codel} \
			limit 100\
			target 250000 interval 2500000 $5
	[ $? = 0 ] || return $?
}

start_qdiscs() {
	echo "Setting up qdiscs on interface ${WAN_IFACE}"
	GUEST_BANDWIDTH_LIMIT="${GUEST_BANDWIDTH_LIMIT_UP}"
	setup_iface ${WAN_IFACE}
	[ $? = 0 ] || return $?

	echo "Setting up qdiscs on interface ${LAN_IFACE}"
	GUEST_BANDWIDTH_LIMIT="${GUEST_BANDWIDTH_LIMIT_DOWN}"
	setup_iface ${LAN_IFACE}
	[ $? = 0 ] || return $?
}

stop_qdiscs() {
	tc qdisc del dev ${WAN_IFACE} root
	tc qdisc del dev ${LAN_IFACE} root
}

start() {
	[ -f "${PIDFILE}" ] && {
		return 0
	}

	[ ! -f /var/log/setup_iptables ] && {
		teardown_iptables 2>/dev/null
		setup_iptables
	}
	touch /var/log/setup_iptables

	for i in ${KERNEL_MODULES}; do
		insmod $i 2>/dev/null
	done

	[ ! -d "${RUNDIR}" ] && {
		mkdir ${RUNDIR}
	}

	[ -x ${BINARY} ] || {
		echo "${NAME} not found: ${BINARY}"
		exit 2
	}

	stop_qdiscs 2>/dev/null
	start_qdiscs || exit 3

	echo -n "Starting ${NAME}: "
	${BINARY} ${CMDLINE_OPTS} "$@"
	retval=$?
	echo
	return ${retval}
}

boot() {
	start "$@"
}

stop() {
	default_stop
	local retval=$?

	stop_qdiscs
	teardown_iptables
	rm -rf /var/log/setup_iptables

	return ${retval}
}

usage() {
	cat <<EOF
Usage: $0 [command]

Commands:
	start
	stop
	restart
	reload
	boot
	init
	status
${EXTRA_HELP}
EOF
}

action() {
	action=${1:-$DEFAULT_ACTION}
	# this shift is required because the start() function accepts
	# parameters from the command line and passes them through to the
	# daemon
	shift

	BINARY=${BINARY:-$(echo $0 | sed 's/.*\///')}
	DISPLAY_NAME=${DISPLAY_NAME:-${NAME:-$BINARY}}
	PIDFILE=${PIDFILE:-$RUNDIR/$BINARY.pid}

	case "${action}" in
		boot|init)
			boot "$@"
			;;
		start|stop|restart|reload|status|start_qdiscs|stop_qdiscs|setup_iptables|teardown_iptables)
			${action} "$@"
			;;
		*)
			usage
			exit 3
	esac
}

action "$@"
exit $?