#!/bin/sh /etc/rc.common

START=70
EXTRA_COMMANDS=clear_leases
LIMIT_DOWN=0
LIMIT_DOWN_BURST=0
LIMIT_UP=0
TC=/usr/sbin/tc
IPT=/usr/sbin/iptables
IPT6=/usr/sbin/ip6tables

IPT_REPLAY=/var/run/luci_splash.iptlog
LOCK=/var/run/luci_splash.lock
[ -x $IPT6 ] && [ -f /proc/net/ipv6_route ] && HAS_IPV6=1

silent() {
	"$@" 2>/dev/null
}

ipt_log() {
	$IPT -I "$@"
	echo $IPT -D "$@" >> $IPT_REPLAY
}

ipt6_log() {
	[ "$HAS_IPV6" = 1 ] || return
	$IPT6 -I "$@"
	echo $IPT6 -D "$@" >> $IPT_REPLAY
}


iface_add() {
	local cfg="$1"

	config_get zone "$cfg" zone
	[ -n "$zone" ] || return 0

	config_get net "$cfg" network
	[ -n "$net" ] || return 0

	config_get ifname "$net" ifname
	[ -n "$ifname" ] || return 0

	config_get ipaddr "$net" ipaddr
	[ -n "$ipaddr" ] || return 0

	config_get netmask "$net" netmask
	[ -n "$netmask" ] || return 0

	config_get ip6addr "$net" ip6addr

	config_get type "$net" type

	parentiface="$(uci -q get network.${net}.ifname)"

	[ -n "$parentiface" ] && [ ! "$type" = "bridge" ] && {
		parentiface=${parentiface#@}
		config_get parentproto   "$parentiface" proto
		config_get parentipaddr  "$parentiface" ipaddr
		config_get parentnetmask "$parentiface" netmask
	}

	eval "$(ipcalc.sh $ipaddr $netmask)"

	logger -s -p info -t splash "Add $NETWORK/$PREFIX ($ifname) to splashed networks."

	### Add interface specific chain entry rules
	ipt_log "prerouting_${zone}_rule" -i "${ifname%:*}" -s "$NETWORK/$PREFIX" -j luci_splash_prerouting -t nat
	ipt_log "forwarding_${zone}_rule"    -i "${ifname%:*}" -s "$NETWORK/$PREFIX" -j luci_splash_forwarding -t filter

	if [ "$HAS_IPV6" = 1 ] && [ -n "$ip6addr" ]; then
		ipt6_log "forwarding_${zone}_rule"    -i "${ifname%:*}" -s "$ip6addr" -j luci_splash_forwarding -t filter
	fi

	### Allow traffic to the same subnet
	$IPT -t nat    -I luci_splash_prerouting -d "$ipaddr/${netmask:-32}" -j RETURN
	$IPT -t filter -I luci_splash_forwarding -d "$ipaddr/${netmask:-32}" -j RETURN

	### Allow traffic to the mesh subnet
	[ "$parentproto" = "static" -a -n "$parentipaddr" ] && {
		$IPT -t nat    -I luci_splash_prerouting -d "$parentipaddr/${parentnetmask:-32}" -j RETURN
		$IPT -t filter -I luci_splash_forwarding -d "$parentipaddr/${parentnetmask:-32}" -j RETURN
	}

	qos_iface_add "$ifname" "$NETWORK" "$PREFIX"
}

iface_del() {
	config_get zone "$1" zone
	[ -n "$zone" ] || return 0

	config_get net "$1" network
	[ -n "$net" ] || return 0

	config_get ifname "$net" ifname
	[ -n "$ifname" ] || return 0

	# Clear interface specific rules
	[ -s $IPT_REPLAY ] && {
		logger -s -p info -t splash "Remove $ifname from splashed networks."
		grep -- "-i ${ifname%:*}" $IPT_REPLAY | while read ln; do silent $ln; done
		sed -ie "/-i ${ifname%:*}/d" $IPT_REPLAY
	}

	qos_iface_del "$ifname"
}

mac_add() {
	config_get mac "$1" mac
	append MACS "$mac"
}

whitelist_add() {
	config_get mac "$1" mac
	iface=$2
	$TC filter add dev "$iface" parent ffff: protocol ip prio 1 u32 match ether src $mac police pass
	$TC filter add dev "$iface" parent 1:0 protocol ip prio 1 u32 match ether dst $mac classid 1:1
}


subnet_add() {
	local cfg="$1"

	config_get ipaddr  "$cfg" ipaddr
	config_get netmask "$cfg" netmask

	[ -n "$ipaddr" ] && {
		$IPT -t nat    -I luci_splash_prerouting -d "$ipaddr/${netmask:-32}" -j RETURN
		$IPT -t filter -I luci_splash_forwarding -d "$ipaddr/${netmask:-32}" -j RETURN
	}
}

qos_iface_add() {
	local iface="$1"
	local network="$2"
	local prefix="$3"

	# 77   -> download root qdisc
	# ffff -> upload root qdisc

	silent $TC qdisc del dev "$iface" root handle 1:
	silent $TC class del dev "$iface" parent 1: classid 1:ffff
	silent $TC class del dev "$iface" parent 1: classid 1:1
	silent $TC filter del dev "$iface" parent ffff: protocol ip prio 1 u32
	silent $TC filter del dev "$iface" parent ffff: protocol ip prio 2 u32
	silent $TC filter del dev "$iface" parent ffff: protocol ip prio 3 u32

	if [ "$LIMIT_UP" -gt 0 -a "$LIMIT_DOWN" -gt 0 ]; then
		# Setup qdiscs
		$TC qdisc add dev "$iface" root handle 1: htb default 1
		silent $TC qdisc add dev "$iface" ingress

		# Default class - all clients which are not otherwise handled are put in that class
		# and share that bandwidth.
		$TC class add dev "$iface" parent 1: classid 1:ffff htb rate ${LIMIT_DOWN}kbit

		# default class and class for whitelisted clients = unlimited
		$TC class add dev "$iface" parent 1: classid 1:1 htb rate 100mbit

		# All traffic to the dhcp subnet is put into the limited class
		$TC filter add dev "$iface" parent 1:0 protocol ip prio 3 u32 match ip dst $network/$prefix classid 1:ffff
		$TC qdisc add dev "$iface" parent 1:ffff sfq perturb 10
                $TC filter add dev "$iface" parent ffff: protocol ip prio 3 u32 match ip src $network/$prefix police rate ${LIMIT_UP}kbit mtu 6k burst 6k drop

		# classify packets by their iptables MARK set in luci_splash_mark_in (mangle table)
		# every client gets his own class and so his own bandwidth limit
		$TC filter add dev "$iface" parent 1:0 protocol ip prio 2 fw

		config_foreach whitelist_add whitelist $iface
	fi
}

qos_iface_del() {
	local iface="$1"
	silent $TC qdisc del dev "$iface" root handle 77:
}

boot() {
	### Setup splash-relay
        uci get uhttpd.splash 2>/dev/null || {
uci batch <<EOF
	set uhttpd.splash=uhttpd
	set uhttpd.splash.home="/www/cgi-bin/splash/"
	set uhttpd.splash.interpreter=".sh=/bin/ash"
	set uhttpd.splash.listen_http="8082"
	set uhttpd.splash.index_page="splash.sh"
	set uhttpd.splash.error_page="/splash.sh"
	set uhttpd.splash.http_keepalive='0'
        commit uhttpd
EOF
	}

	### We are started by the firewall include
	exit 0
}

start() {
	lock $LOCK
	logger -s -p info -t splash "Starting luci-splash"
	include /lib/network
	. /lib/functions/network.sh
	scan_interfaces
	config_load luci_splash

	### Find QoS limits
	config_get LIMIT_UP general limit_up
	config_get LIMIT_DOWN general limit_down
	config_get LIMIT_DOWN_BURST general limit_down_burst

	LIMIT_UP="$((8*${LIMIT_UP:-0}))"
	LIMIT_DOWN="$((8*${LIMIT_DOWN:-0}))"
	LIMIT_DOWN_BURST="${LIMIT_DOWN_BURST:+$((8*$LIMIT_DOWN_BURST))}"
	LIMIT_DOWN_BURST="${LIMIT_DOWN_BURST:-$(($LIMIT_DOWN / 5 * 6))}"

	### Load required modules
	[ "$LIMIT_UP" -gt 0 -a "$LIMIT_DOWN" -gt 0 ] && {
		silent insmod act_police
		silent insmod cls_fw
		silent insmod cls_u32
		silent insmod sch_htb
		silent insmod sch_sfq
		silent insmod sch_ingress
	}

	### Create subchains
	$IPT -t nat    -N luci_splash_prerouting
	$IPT -t nat    -N luci_splash_leases
	$IPT -t filter -N luci_splash_forwarding
	$IPT -t filter -N luci_splash_filter

	if [ "$HAS_IPV6" = 1 ]; then
		$IPT6 -t filter -N luci_splash_forwarding
		$IPT6 -t filter -N luci_splash_filter
	fi

	### Clear iptables replay log
	[ -s $IPT_REPLAY ] && . $IPT_REPLAY
	echo -n > $IPT_REPLAY

	### Add interface independent prerouting rules
	$IPT -t nat -A luci_splash_prerouting -j luci_splash_leases
	$IPT -t nat -A luci_splash_leases -p udp --dport 53 -j REDIRECT --to-ports 53
	$IPT -t nat -A luci_splash_leases -p tcp --dport 80 -j REDIRECT --to-ports 8082

	### Add interface independent forwarding rules
	$IPT -t filter -A luci_splash_forwarding -j luci_splash_filter
	$IPT -t filter -A luci_splash_filter -p tcp -j REJECT --reject-with tcp-reset
	$IPT -t filter -A luci_splash_filter -j REJECT --reject-with icmp-net-prohibited

	if [ "$HAS_IPV6" = 1 ]; then
		$IPT6 -t filter -A luci_splash_forwarding -j luci_splash_filter
		$IPT6 -t filter -A luci_splash_filter -p tcp -j REJECT --reject-with tcp-reset
		$IPT6 -t filter -A luci_splash_filter -j REJECT --reject-with adm-prohibited
	fi

	### Add QoS chain
	$IPT -t mangle -N luci_splash_mark_out
	$IPT -t mangle -N luci_splash_mark_in
	$IPT -t mangle -I PREROUTING  -j luci_splash_mark_out
	$IPT -t mangle -I POSTROUTING -j luci_splash_mark_in

	if [ "$HAS_IPV6" = 1 ]; then
		$IPT6 -t mangle -N luci_splash_mark_out
		$IPT6 -t mangle -N luci_splash_mark_in
		$IPT6 -t mangle -I PREROUTING  -j luci_splash_mark_out
		$IPT6 -t mangle -I POSTROUTING -j luci_splash_mark_in
	fi

	### Build the main and portal rule
	config_foreach iface_add iface
	config_foreach subnet_add subnet

	### Add the community homepage to the list of allowed destination subnets
	hp=$(uci -q get freifunk.community.homepage) && {
		chp=${hp#http*://}
		chp=${chp%%/*}
		$IPT -t nat    -I luci_splash_prerouting -d "${chp}/32" -j RETURN
		$IPT -t filter -I luci_splash_forwarding -d "${chp}/32" -j RETURN
	}

	### Find active mac addresses
	MACS=""

	
	config_foreach mac_add blacklist
	config_foreach mac_add whitelist

	config_load luci_splash_leases
	config_foreach mac_add lease

	### Add crontab entry
	test -f /etc/crontabs/root || touch /etc/crontabs/root
	grep -q luci-splash /etc/crontabs/root || {
		echo '*/5 * * * * 	/usr/sbin/luci-splash sync' >> /etc/crontabs/root
	}

	lock -u $LOCK

	### Populate iptables
	[ -n "$MACS" ] && luci-splash add-rules $MACS
}

stop() {
	lock $LOCK

	include /lib/network
	scan_interfaces
	config_load luci_splash

	### Clear interface rules
	config_foreach iface_del iface

	silent $IPT -t mangle -D PREROUTING  -j luci_splash_mark_out
	silent $IPT -t mangle -D POSTROUTING -j luci_splash_mark_in

	if [ "$HAS_IPV6" = 1 ]; then
		silent $IPT6 -t mangle -D PREROUTING  -j luci_splash_mark_out
		silent $IPT6 -t mangle -D POSTROUTING -j luci_splash_mark_in
	fi

	### Clear subchains
	silent $IPT -t nat    -F luci_splash_prerouting
	silent $IPT -t nat    -F luci_splash_leases
	silent $IPT -t filter -F luci_splash_forwarding
	silent $IPT -t filter -F luci_splash_filter
	silent $IPT -t mangle -F luci_splash_mark_out
	silent $IPT -t mangle -F luci_splash_mark_in

	if [ "$HAS_IPV6" = 1 ]; then
		$IPT6 -t filter -F luci_splash_forwarding
		$IPT6 -t filter -F luci_splash_filter
		$IPT6 -t mangle -F luci_splash_mark_out
		$IPT6 -t mangle -F luci_splash_mark_in
	fi

	### Delete subchains
	silent $IPT -t nat    -X luci_splash_prerouting
	silent $IPT -t nat    -X luci_splash_leases
	silent $IPT -t filter -X luci_splash_forwarding
	silent $IPT -t filter -X luci_splash_filter
	silent $IPT -t mangle -X luci_splash_mark_out
	silent $IPT -t mangle -X luci_splash_mark_in
	if [ "$HAS_IPV6" = 1 ]; then
		$IPT6 -t filter -X luci_splash_forwarding
		$IPT6 -t filter -X luci_splash_filter
		$IPT6 -t mangle -X luci_splash_mark_out
		$IPT6 -t mangle -X luci_splash_mark_in
	fi
	sed -ie '/\/usr\/sbin\/luci-splash sync/d' /var/spool/cron/crontabs/root

	lock -u $LOCK
}

clear_leases() {
	### Find active mac addresses
	MACS=""
	config_foreach mac_add lease

	### Clear leases
	[ -n "$MACS" ] && luci-splash remove $MACS
}