#!/bin/sh /etc/rc.common
# Copyright (C) 2007-2012 OpenWrt.org

START=19

USE_PROCD=1
PROG=/usr/sbin/dnsmasq

ADD_LOCAL_DOMAIN=1
ADD_LOCAL_HOSTNAME=1
ADD_WAN_FQDN=0
ADD_LOCAL_FQDN=""

BASECONFIGFILE="/var/etc/dnsmasq.conf"
BASEHOSTFILE="/tmp/hosts/dhcp"
TRUSTANCHORSFILE="/usr/share/dnsmasq/trust-anchors.conf"
TIMEVALIDFILE="/var/state/dnsmasqsec"
BASEDHCPSTAMPFILE="/var/run/dnsmasq"
DHCPBOGUSHOSTNAMEFILE="/usr/share/dnsmasq/dhcpbogushostname.conf"
RFC6761FILE="/usr/share/dnsmasq/rfc6761.conf"
DHCPSCRIPT="/usr/lib/dnsmasq/dhcp-script.sh"
DHCPSCRIPT_DEPENDS="/usr/share/libubox/jshn.sh /usr/bin/jshn /bin/ubus"

DNSMASQ_DHCP_VER=4

dnsmasq_ignore_opt() {
	local opt="$1"

	if [ -z "$dnsmasq_features" ]; then
		dnsmasq_features="$(dnsmasq --version | grep -m1 'Compile time options:' | cut -d: -f2) "
		[ "${dnsmasq_features#* DHCP }" = "$dnsmasq_features" ] || dnsmasq_has_dhcp=1
		[ "${dnsmasq_features#* DHCPv6 }" = "$dnsmasq_features" ] || dnsmasq_has_dhcp6=1
		[ "${dnsmasq_features#* DNSSEC }" = "$dnsmasq_features" ] || dnsmasq_has_dnssec=1
		[ "${dnsmasq_features#* TFTP }" = "$dnsmasq_features" ] || dnsmasq_has_tftp=1
		[ "${dnsmasq_features#* ipset }" = "$dnsmasq_features" ] || dnsmasq_has_ipset=1
	fi

	case "$opt" in
		dhcp-duid|\
		ra-param)
			[ -z "$dnsmasq_has_dhcp6" ] ;;
		dhcp-*|\
		bootp-*|\
		pxe-*)
			[ -z "$dnsmasq_has_dhcp" ] ;;
		dnssec*|\
		trust-anchor)
			if [ -z "$dnsmasq_has_dnssec" ]; then
				echo "dnsmasq: \"$opt\" requested, but dnssec support is not available" >&2
				exit 1
			fi
			return 1
			;;
		tftp-*)
			[ -z "$dnsmasq_has_tftp" ] ;;
		ipset)
			[ -z "$dnsmasq_has_ipset" ] ;;
		*)
			return 1
	esac
}

xappend() {
	local value="${1#--}"
	local opt="${value%%=*}"

	if ! dnsmasq_ignore_opt "$opt"; then
		echo "$value" >>$CONFIGFILE_TMP
	fi
}

hex_to_hostid() {
	local var="$1"
	local hex="${2#0x}" # strip optional "0x" prefix

	if [ -n "${hex//[0-9a-fA-F]/}" ]; then
		# is invalid hex literal
		return 1
	fi

	# convert into host id
	export "$var=$(
		printf "%0x:%0x" \
		$(((0x$hex >> 16) % 65536)) \
		$(( 0x$hex        % 65536))
		)"

	return 0
}

dhcp_calc() {
	local ip="$1"
	local res=0

	while [ -n "$ip" ]; do
		part="${ip%%.*}"
		res="$(($res * 256))"
		res="$(($res + $part))"
		[ "${ip%.*}" != "$ip" ] && ip="${ip#*.}" || ip=
	done
	echo "$res"
}

dhcp_check() {
	local ifname="$1"
	local stamp="${BASEDHCPSTAMPFILE_CFG}.${ifname}.dhcp"
	local rv=0

	[ -s "$stamp" ] && return $(cat "$stamp")

	# If interface is down, skip it.
	# The init script will be called again once the link is up
	case "$(devstatus "$ifname" | jsonfilter -e @.up)" in
		false) return 1;;
	esac

	udhcpc -n -q -s /bin/true -t 1 -i "$ifname" >&- && rv=1 || rv=0

	echo $rv > "$stamp"
	return $rv
}

log_once() {
	pidof dnsmasq >/dev/null || \
		logger -t dnsmasq "$@"
}

has_handler() {
	local file

	for file in /etc/hotplug.d/dhcp/* /etc/hotplug.d/tftp/* /etc/hotplug.d/neigh/*; do
		[ -f "$file" ] && return 0
	done

	return 1
}

append_bool() {
	local section="$1"
	local option="$2"
	local value="$3"
	local default="$4"
	local _loctmp
	[ -z "$default" ] && default="0"
	config_get_bool _loctmp "$section" "$option" "$default"
	[ $_loctmp -gt 0 ] && xappend "$value"
}

append_parm() {
	local section="$1"
	local option="$2"
	local switch="$3"
	local default="$4"
	local _loctmp
	config_get _loctmp "$section" "$option" "$default"
	[ -z "$_loctmp" ] && return 0
	xappend "$switch=$_loctmp"
}

append_server() {
	xappend "--server=$1"
}

append_rev_server() {
	xappend "--rev-server=$1"
}

append_address() {
	xappend "--address=$1"
}

append_ipset() {
	xappend "--ipset=$1"
}

append_connmark_allowlist() {
	xappend "--connmark-allowlist=$1"
}

append_interface() {
	network_get_device ifname "$1" || ifname="$1"
	xappend "--interface=$ifname"
}

append_listenaddress() {
	xappend "--listen-address=$1"
}

append_notinterface() {
	network_get_device ifname "$1" || ifname="$1"
	xappend "--except-interface=$ifname"
}

ismounted() {
	local filename="$1"
	local dirname
	for dirname in $EXTRA_MOUNT ; do
		case "$filename" in
			"${dirname}/"* | "${dirname}" )
				return 1
				;;
		esac
	done

	return 0
}

append_addnhosts() {
	ismounted "$1" || append EXTRA_MOUNT "$1"
	xappend "--addn-hosts=$1"
}

append_bogusnxdomain() {
	xappend "--bogus-nxdomain=$1"
}

append_pxe_service() {
	xappend "--pxe-service=$1"
}

append_interface_name() {
	xappend "--interface-name=$1,$2"
}

filter_dnsmasq() {
	local cfg="$1" func="$2" match_cfg="$3" found_cfg

	# use entry when no instance entry set, or if it matches
	config_get found_cfg "$cfg" "instance"
	if [ -z "$found_cfg" ] || [ "$found_cfg" = "$match_cfg" ]; then
		$func $cfg
	fi
}

dhcp_subscrid_add() {
	local cfg="$1"

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

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

	xappend "--dhcp-subscrid=set:$networkid,$subscriberid"

	config_get_bool force "$cfg" force 0

	dhcp_option_add "$cfg" "$networkid" "$force"
}

dhcp_remoteid_add() {
	local cfg="$1"

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

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

	xappend "--dhcp-remoteid=set:$networkid,$remoteid"

	config_get_bool force "$cfg" force 0

	dhcp_option_add "$cfg" "$networkid" "$force"
}

dhcp_circuitid_add() {
	# TODO: DHCPV6 does not have circuitid; catch "option6:"
	local cfg="$1"

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

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

	xappend "--dhcp-circuitid=set:$networkid,$circuitid"

	config_get_bool force "$cfg" force 0

	dhcp_option_add "$cfg" "$networkid" "$force"
}

dhcp_userclass_add() {
	local cfg="$1"

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

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

	xappend "--dhcp-userclass=set:$networkid,$userclass"

	config_get_bool force "$cfg" force 0

	dhcp_option_add "$cfg" "$networkid" "$force"
}

dhcp_vendorclass_add() {
	# TODO: DHCPV6 vendor class has stricter definitions; catch? fixup?
	local cfg="$1"

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

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

	xappend "--dhcp-vendorclass=set:$networkid,$vendorclass"

	config_get_bool force "$cfg" force 0

	dhcp_option_add "$cfg" "$networkid" "$force"
}

dhcp_match_add() {
	local cfg="$1"

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

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

	xappend "--dhcp-match=set:$networkid,$match"

	config_get_bool force "$cfg" force 0

	dhcp_option_add "$cfg" "$networkid" "$force"
}

dhcp_host_add() {
	local cfg="$1"
	local hosttag nametime addrs duids macs tags

	config_get_bool force "$cfg" force 0

	config_get networkid "$cfg" networkid
	[ -n "$networkid" ] && dhcp_option_add "$cfg" "$networkid" "$force"

	config_get_bool enable "$cfg" enable 1
	[ "$enable" = "0" ] && return 0

	config_get name "$cfg" name
	config_get ip "$cfg" ip
	config_get hostid "$cfg" hostid

	[ -z "$ip" ] && [ -z "$name" ] && [ -z "$hostid" ] && return 0

	config_get_bool dns "$cfg" dns 0
	[ "$dns" = "1" ] && [ -n "$ip" ] && [ -n "$name" ] && {
		echo "$ip $name${DOMAIN:+.$DOMAIN}" >> $HOSTFILE_TMP
	}

	config_get mac "$cfg" mac
	config_get duid "$cfg" duid
	config_get tag "$cfg" tag

	if [ -n "$mac" ]; then
		# --dhcp-host=00:20:e0:3b:13:af,192.168.0.199,lap
		# many MAC are possible to track a laptop ON/OFF dock
		for m in $mac; do append macs "$m" ","; done
	fi

	if [ $DNSMASQ_DHCP_VER -eq 6 ] && [ -n "$duid" ]; then
		# --dhcp-host=id:00:03:00:01:12:00:00:01:02:03,[::beef],lap
		# one (virtual) machine gets one DUID per RFC3315
		duids="id:${duid// */}"
	fi

	if [ -z "$macs" ] && [ -z "$duids" ]; then
		# --dhcp-host=lap,192.168.0.199,[::beef]
		[ -n "$name" ] || return 0
		macs="$name"
		name=""
	fi

	if [ -n "$hostid" ]; then
		hex_to_hostid hostid "$hostid"
	fi

	if [ -n "$tag" ]; then
		for t in $tag; do append tags "$t" ",set:"; done
	fi

	config_get_bool broadcast "$cfg" broadcast 0
	config_get leasetime "$cfg" leasetime

	[ "$broadcast" = "0" ] && broadcast= || broadcast=",set:needs-broadcast"

	hosttag="${networkid:+,set:${networkid}}${tags:+,set:${tags}}$broadcast"
	nametime="${name:+,$name}${leasetime:+,$leasetime}"

	if [ $DNSMASQ_DHCP_VER -eq 6 ]; then
		addrs="${ip:+,$ip}${hostid:+,[::$hostid]}"
		xappend "--dhcp-host=$macs${duids:+,$duids}$hosttag$addrs$nametime"
	else
		xappend "--dhcp-host=$macs$hosttag${ip:+,$ip}$nametime"
	fi
}

dhcp_this_host_add() {
	local net="$1"
	local ifname="$2"
	local mode="$3"
	local routerstub routername ifdashname
	local lanaddr lanaddr6 lanaddrs6 ulaprefix

	if [ "$mode" -gt 0 ] ; then
		ifdashname="${ifname//./-}"
		routerstub="$( md5sum /etc/os-release )"
		routerstub="router-${routerstub// */}"
		routername="$( uci_get system @system[0] hostname $routerstub )"

		if [ "$mode" -gt 1 ] ; then
			if [ "$mode" -gt 2 ] ; then
				if [ "$mode" -gt 3 ] ; then
					append_interface_name "$ifdashname.$routername.$DOMAIN" "$ifname"
				fi

				append_interface_name "$routername.$DOMAIN" "$ifname"
			fi

			# All IP addresses discovered by dnsmasq will be labeled (except fe80::)
			append_interface_name "$routername" "$ifname"

		else
			# This uses a static host file entry for only limited addresses.
			# Use dnsmasq option "--expandhosts" to enable FQDN on host files.
			ulaprefix="$(uci_get network @globals[0] ula_prefix)"
			network_get_ipaddr lanaddr "$net"
			network_get_ipaddrs6 lanaddrs6 "$net"

			if [ -n "$lanaddr" ] ; then
				dhcp_domain_add "" "$routername" "$lanaddr"
			fi

			if [ -n "$ulaprefix" ] && [ -n "$lanaddrs6" ] ; then
				for lanaddr6 in $lanaddrs6 ; do
					case "$lanaddr6" in
					"${ulaprefix%%:/*}"*)
						dhcp_domain_add "" "$routername" "$lanaddr6"
						;;
					esac
				done
			fi
		fi
	fi
}

dhcp_tag_add() {
	# NOTE: dnsmasq has explicit "option6:" prefix for DHCPv6 so no collisions
	local cfg="$1"

	tag="$cfg"

	[ -n "$tag" ] || return 0

	config_get_bool force "$cfg" force 0
	[ "$force" = "0" ] && force=

	config_get option "$cfg" dhcp_option
	for o in $option; do
		xappend "--dhcp-option${force:+-force}=tag:$tag,$o"
	done
}

dhcp_mac_add() {
	local cfg="$1"

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

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

	xappend "--dhcp-mac=$networkid,$mac"

	dhcp_option_add "$cfg" "$networkid"
}

dhcp_boot_add() {
	# TODO: BOOTURL is different between DHCPv4 and DHCPv6
	local cfg="$1"

	config_get networkid "$cfg" networkid

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

	config_get servername "$cfg" servername
	config_get serveraddress "$cfg" serveraddress

	[ -n "$serveraddress" ] && [ ! -n "$servername" ] && return 0

	xappend "--dhcp-boot=${networkid:+net:$networkid,}${filename}${servername:+,$servername}${serveraddress:+,$serveraddress}"

	config_get_bool force "$cfg" force 0

	dhcp_option_add "$cfg" "$networkid" "$force"
}


dhcp_add() {
	local cfg="$1"
	local dhcp6range="::"
	local nettag
	local tags

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

	config_get networkid "$cfg" networkid
	[ -n "$networkid" ] || networkid="$net"

	network_get_device ifname "$net" || return 0

	[ "$cachelocal" = "0" ] && network_get_dnsserver dnsserver "$net" && {
		DNS_SERVERS="$DNS_SERVERS $dnsserver"
	}

	append_bool "$cfg" ignore "--no-dhcp-interface=$ifname" && {
		# Many ISP do not have useful names for DHCP customers (your WAN).
		dhcp_this_host_add "$net" "$ifname" "$ADD_WAN_FQDN"
		return 0
	}

	network_get_subnet subnet "$net" || return 0
	network_get_protocol proto "$net" || return 0

	# Do not support non-static interfaces for now
	[ static = "$proto" ] || return 0

	# Override interface netmask with dhcp config if applicable
	config_get netmask "$cfg" netmask "${subnet##*/}"

	#check for an already active dhcp server on the interface, unless 'force' is set
	config_get_bool force "$cfg" force 0
	[ $force -gt 0 ] || dhcp_check "$ifname" || {
		logger -t dnsmasq \
			"found already running DHCP-server on interface '$ifname'" \
			"refusing to start, use 'option force 1' to override"
		return 0
	}

	config_get start "$cfg" start 100
	config_get limit "$cfg" limit 150
	config_get leasetime "$cfg" leasetime 12h
	config_get options "$cfg" options
	config_get_bool dynamicdhcp "$cfg" dynamicdhcp 1

	config_get dhcpv4 "$cfg" dhcpv4
	config_get dhcpv6 "$cfg" dhcpv6

	config_get ra "$cfg" ra
	config_get ra_management "$cfg" ra_management
	config_get ra_preference "$cfg" ra_preference
	config_get dns "$cfg" dns

	config_list_foreach "$cfg" "interface_name" append_interface_name "$ifname"

	# Put the router host name on this DHCP served interface address(es)
	dhcp_this_host_add "$net" "$ifname" "$ADD_LOCAL_FQDN"

	start="$( dhcp_calc "$start" )"

	add_tag() {
		tags="${tags}tag:$1,"
	}
	config_list_foreach "$cfg" tag add_tag

	nettag="${networkid:+set:${networkid},}"

	if [ "$limit" -gt 0 ] ; then
		limit=$((limit-1))
	fi

	eval "$(ipcalc.sh "${subnet%%/*}" $netmask $start $limit)"

	if [ "$dynamicdhcp" = "0" ] ; then
		END="static"
		dhcp6range="::,static"
	else
		dhcp6range="::1000,::ffff"
	fi


	if [ "$dhcpv4" != "disabled" ] ; then
		xappend "--dhcp-range=$tags$nettag$START,$END,$NETMASK,$leasetime${options:+ $options}"
	fi


	if [ $DNSMASQ_DHCP_VER -eq 6 ] && [ "$ra" = "server" ] ; then
		# Note: dnsmasq cannot just be a DHCPv6 server (all-in-1)
		# and let some other machine(s) send RA pointing to it.

		case $ra_preference in
		*high*)
			xappend "--ra-param=$ifname,high,0,7200"
			;;
		*low*)
			xappend "--ra-param=$ifname,low,0,7200"
			;;
		*)
			# Send UNSOLICITED RA at default interval and live for 2 hours.
			# TODO: convert flexible lease time into route life time (only seconds).
			xappend "--ra-param=$ifname,0,7200"
			;;
		esac

		if [ "$dhcpv6" = "disabled" ] ; then
			ra_management="3"
		fi


		case $ra_management in
		0)
			# SLACC with DCHP for extended options
			xappend "--dhcp-range=$nettag::,constructor:$ifname,ra-stateless,ra-names"
			;;
		2)
			# DHCP address and RA only for management redirection
			xappend "--dhcp-range=$nettag$dhcp6range,constructor:$ifname,$leasetime"
			;;
		3)
			# SLAAC only but dnsmasq attempts to link HOSTNAME, DHCPv4 MAC, and SLAAC
			xappend "--dhcp-range=$nettag::,constructor:$ifname,ra-only,ra-names"
			;;
		*)
			# SLAAC and full DHCP
			xappend "--dhcp-range=$nettag$dhcp6range,constructor:$ifname,slaac,ra-names,$leasetime"
			;;
		esac

		if [ -n "$dns" ]; then
			dnss=""
			for d in $dns; do append dnss "[$d]" ","; done
		else
			dnss="[::]"
		fi

		dhcp_option_append "option6:dns-server,$dnss" "$networkid"
	fi

	dhcp_option_add "$cfg" "$networkid" 0
	dhcp_option_add "$cfg" "$networkid" 2
}

dhcp_option_append() {
	local option="$1"
	local networkid="$2"
	local force="$3"

	xappend "--dhcp-option${force:+-force}=${networkid:+$networkid,}$option"
}

dhcp_option_add() {
	# NOTE: dnsmasq has explicit "option6:" prefix for DHCPv6 so no collisions
	local cfg="$1"
	local networkid="$2"
	local force="$3"
	local opt="dhcp_option"

	[ "$force" = "0" ] && force=
	[ "$force" = "2" ] && opt="dhcp_option_force"

	local list_len
	config_get list_len "$cfg" "${opt}_LENGTH"

	if [ -n "$list_len" ]; then
		config_list_foreach "$cfg" "$opt" dhcp_option_append "$networkid" "$force"
	else
		config_get dhcp_option "$cfg" "$opt"

		[ -n "$dhcp_option" ] && echo "Warning: the 'option $opt' syntax is deprecated, use 'list $opt'" >&2

		local option
		for option in $dhcp_option; do
			dhcp_option_append "$option" "$networkid" "$force"
		done
	fi
}

dhcp_domain_add() {
	local cfg="$1"
	local ip name names record

	config_get names "$cfg" name "$2"
	[ -n "$names" ] || return 0

	config_get ip "$cfg" ip "$3"
	[ -n "$ip" ] || return 0

	for name in $names; do
		record="${record:+$record }$name"
	done

	echo "$ip $record" >> $HOSTFILE_TMP
}

dhcp_srv_add() {
	local cfg="$1"

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

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

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

	config_get class "$cfg" class
	config_get weight "$cfg" weight

	local service="$srv,$target,$port${class:+,$class${weight:+,$weight}}"

	xappend "--srv-host=$service"
}

dhcp_mx_add() {
	local cfg="$1"
	local domain relay pref

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

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

	config_get pref "$cfg" pref 0

	local service="$domain,$relay,$pref"

	xappend "--mx-host=$service"
}

dhcp_cname_add() {
	local cfg="$1"
	local cname target

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

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

	xappend "--cname=${cname},${target}"
}

dhcp_hostrecord_add() {
	local cfg="$1"
	local names addresses record val

	config_get names "$cfg" name "$2"
	if [ -z "$names" ]; then
		return 0
	fi

	config_get addresses "$cfg" ip "$3"
	if [ -z "$addresses" ]; then
		return 0
	fi

	for val in $names $addresses; do
		record="${record:+$record,}$val"
	done

	xappend "--host-record=$record"
}

dhcp_relay_add() {
	local cfg="$1"
	local local_addr server_addr interface

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

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

	config_get interface "$cfg" interface
	if [ -z "$interface" ]; then
		xappend "--dhcp-relay=$local_addr,$server_addr"
	else
		network_get_device ifname "$interface" || return
		xappend "--dhcp-relay=$local_addr,$server_addr,$ifname"
	fi
}

dnsmasq_ipset_add() {
	local cfg="$1"
	local ipsets domains

	add_ipset() {
		ipsets="${ipsets:+$ipsets,}$1"
	}

	add_domain() {
		# leading '/' is expected
		domains="$domains/$1"
	}

	config_list_foreach "$cfg" "name" add_ipset
	config_list_foreach "$cfg" "domain" add_domain

	if [ -z "$ipsets" ] || [ -z "$domains" ]; then
		return 0
	fi

	xappend "--ipset=$domains/$ipsets"
}

dnsmasq_start()
{
	local cfg="$1"
	local disabled user_dhcpscript
	local resolvfile resolvdir localuse=0

	config_get_bool disabled "$cfg" disabled 0
	[ "$disabled" -gt 0 ] && return 0

	# reset list of DOMAINS, DNS servers and EXTRA mounts (for each dnsmasq instance)
	DNS_SERVERS=""
	DOMAIN=""
	EXTRA_MOUNT=""
	CONFIGFILE="${BASECONFIGFILE}.${cfg}"
	CONFIGFILE_TMP="${CONFIGFILE}.$$"
	HOSTFILE="${BASEHOSTFILE}.${cfg}"
	HOSTFILE_TMP="${HOSTFILE}.$$"
	BASEDHCPSTAMPFILE_CFG="${BASEDHCPSTAMPFILE}.${cfg}"

	# before we can call xappend
	mkdir -p /var/run/dnsmasq/
	mkdir -p $(dirname $CONFIGFILE)
	mkdir -p $(dirname $HOSTFILE)
	mkdir -p /var/lib/misc
	chown dnsmasq:dnsmasq /var/run/dnsmasq

	echo "# auto-generated config file from /etc/config/dhcp" > $CONFIGFILE_TMP
	echo "# auto-generated config file from /etc/config/dhcp" > $HOSTFILE_TMP

	local dnsmasqconffile="/etc/dnsmasq.${cfg}.conf"
	if [ ! -r "$dnsmasqconffile" ]; then
		dnsmasqconffile=/etc/dnsmasq.conf
	fi

	# if we did this last, we could override auto-generated config
	[ -f "${dnsmasqconffile}" ] && {
		xappend "--conf-file=${dnsmasqconffile}"
	}

	$PROG --version | grep -osqE "^Compile time options:.* DHCPv6( |$)" && DHCPv6CAPABLE=1 || DHCPv6CAPABLE=0


	if [ -x /usr/sbin/odhcpd ] && [ -x /etc/init.d/odhcpd ] ; then
		local odhcpd_is_main odhcpd_is_enabled
		config_get odhcpd_is_main odhcpd maindhcp 0
		/etc/init.d/odhcpd enabled && odhcpd_is_enabled=1 || odhcpd_is_enabled=0


		if [ "$odhcpd_is_enabled" -eq 0 ] && [ "$DHCPv6CAPABLE" -eq 1 ] ; then
			# DHCP V4 and V6 in DNSMASQ
			DNSMASQ_DHCP_VER=6
		elif [ "$odhcpd_is_main" -gt 0 ] ; then
			# ODHCPD is doing it all
			DNSMASQ_DHCP_VER=0
		else
			# You have ODHCPD but use DNSMASQ for DHCPV4
			DNSMASQ_DHCP_VER=4
		fi

	elif [ "$DHCPv6CAPABLE" -eq 1 ] ; then
		# DHCP V4 and V6 in DNSMASQ
		DNSMASQ_DHCP_VER=6
	else
		DNSMASQ_DHCP_VER=4
	fi

	# Allow DHCP/DHCPv6 to be handled by ISC DHCPD
	if [ -x /usr/sbin/dhcpd ] ; then
		if [ -x /etc/init.d/dhcpd ] ; then
			/etc/init.d/dhcpd enabled && DNSMASQ_DHCP_VER=0
		fi
		if [ -x /etc/init.d/dhcpd6 ] && [ "$DNSMASQ_DHCP_VER" -gt 0 ] ; then
			/etc/init.d/dhcpd6 enabled && DNSMASQ_DHCP_VER=4
		fi
	fi

	append_bool "$cfg" authoritative "--dhcp-authoritative"
	append_bool "$cfg" nodaemon "--no-daemon"
	append_bool "$cfg" domainneeded "--domain-needed"
	append_bool "$cfg" filterwin2k "--filterwin2k"
	append_bool "$cfg" nohosts "--no-hosts"
	append_bool "$cfg" nonegcache "--no-negcache"
	append_bool "$cfg" strictorder "--strict-order"
	append_bool "$cfg" logqueries "--log-queries=extra"
	append_bool "$cfg" noresolv "--no-resolv"
	append_bool "$cfg" localise_queries "--localise-queries"
	append_bool "$cfg" readethers "--read-ethers"

	local instance_name="dnsmasq.$cfg"
	if [ "$cfg" = "$DEFAULT_INSTANCE" ]; then
		instance_name="dnsmasq"
	fi
	config_get_bool dbus "$cfg" "dbus" 0
	[ $dbus -gt 0 ] && xappend "--enable-dbus=uk.org.thekelleys.$instance_name"
	config_get_bool ubus "$cfg" "ubus" 1
	[ $ubus -gt 0 ] && xappend "--enable-ubus=$instance_name"

	append_bool "$cfg" expandhosts "--expand-hosts"
	config_get tftp_root "$cfg" "tftp_root"
	[ -n "$tftp_root" ] && mkdir -p "$tftp_root" && append_bool "$cfg" enable_tftp "--enable-tftp"
	append_bool "$cfg" tftp_no_fail "--tftp-no-fail"
	append_bool "$cfg" nonwildcard "--bind-dynamic" 1
	append_bool "$cfg" fqdn "--dhcp-fqdn"
	append_bool "$cfg" proxydnssec "--proxy-dnssec"
	append_bool "$cfg" localservice "--local-service"
	append_bool "$cfg" logdhcp "--log-dhcp"
	append_bool "$cfg" quietdhcp "--quiet-dhcp"
	append_bool "$cfg" sequential_ip "--dhcp-sequential-ip"
	append_bool "$cfg" allservers "--all-servers"
	append_bool "$cfg" noping "--no-ping"
	append_bool "$cfg" rapidcommit "--dhcp-rapid-commit"
	append_bool "$cfg" scriptarp "--script-arp"

	append_parm "$cfg" logfacility "--log-facility"

	append_parm "$cfg" cachesize "--cache-size"
	append_parm "$cfg" dnsforwardmax "--dns-forward-max"
	append_parm "$cfg" port "--port"
	append_parm "$cfg" ednspacket_max "--edns-packet-max"
	append_parm "$cfg" dhcpleasemax "--dhcp-lease-max"
	append_parm "$cfg" "queryport" "--query-port"
	append_parm "$cfg" "minport" "--min-port"
	append_parm "$cfg" "maxport" "--max-port"
	append_parm "$cfg" "domain" "--domain"
	append_parm "$cfg" "local" "--local"
	config_list_foreach "$cfg" "listen_address" append_listenaddress
	config_list_foreach "$cfg" "server" append_server
	config_list_foreach "$cfg" "rev_server" append_rev_server
	config_list_foreach "$cfg" "address" append_address
	config_list_foreach "$cfg" "ipset" append_ipset

	local connmark_allowlist_enable
	config_get connmark_allowlist_enable "$cfg" connmark_allowlist_enable 0
	[ "$connmark_allowlist_enable" -gt 0 ] && {
		append_parm "$cfg" "connmark_allowlist_enable" "--connmark-allowlist-enable"
		config_list_foreach "$cfg" "connmark_allowlist" append_connmark_allowlist
	}

	[ -n "$BOOT" ] || {
		config_list_foreach "$cfg" "interface" append_interface
		config_list_foreach "$cfg" "notinterface" append_notinterface
	}
	config_get_bool ignore_hosts_dir "$cfg" ignore_hosts_dir 0
	if [ "$ignore_hosts_dir" = "1" ]; then
		xappend "--addn-hosts=$HOSTFILE"
		append EXTRA_MOUNT "$HOSTFILE"
	else
		xappend "--addn-hosts=$(dirname $HOSTFILE)"
		append EXTRA_MOUNT "$(dirname $HOSTFILE)"
	fi
	config_list_foreach "$cfg" "addnhosts" append_addnhosts
	config_list_foreach "$cfg" "bogusnxdomain" append_bogusnxdomain
	append_parm "$cfg" "leasefile" "--dhcp-leasefile" "/tmp/dhcp.leases"
	append_parm "$cfg" "serversfile" "--servers-file"
	append_parm "$cfg" "tftp_root" "--tftp-root"
	append_parm "$cfg" "dhcp_boot" "--dhcp-boot"
	append_parm "$cfg" "local_ttl" "--local-ttl"
	append_parm "$cfg" "max_ttl" "--max-ttl"
	append_parm "$cfg" "min_cache_ttl" "--min-cache-ttl"
	append_parm "$cfg" "max_cache_ttl" "--max-cache-ttl"
	append_parm "$cfg" "pxe_prompt" "--pxe-prompt"
	append_parm "$cfg" "tftp_unique_root" "--tftp-unique-root"
	config_list_foreach "$cfg" "pxe_service" append_pxe_service
	config_get DOMAIN "$cfg" domain

	config_get_bool ADD_LOCAL_DOMAIN "$cfg" add_local_domain 1
	config_get_bool ADD_LOCAL_HOSTNAME "$cfg" add_local_hostname 1
	config_get ADD_LOCAL_FQDN "$cfg" add_local_fqdn ""
	config_get ADD_WAN_FQDN "$cfg" add_wan_fqdn 0

	if [ -z "$ADD_LOCAL_FQDN" ] ; then
		# maintain support for previous UCI
		ADD_LOCAL_FQDN="$ADD_LOCAL_HOSTNAME"
	fi

	config_get user_dhcpscript $cfg dhcpscript
	if has_handler || [ -n "$user_dhcpscript" ]; then
		xappend "--dhcp-script=$DHCPSCRIPT"
		xappend "--script-arp"
	fi

	config_get leasefile $cfg leasefile "/tmp/dhcp.leases"
	[ -n "$leasefile" ] && [ ! -e "$leasefile" ] && touch "$leasefile"
	config_get_bool cachelocal "$cfg" cachelocal 1

	config_get_bool noresolv "$cfg" noresolv 0
	if [ "$noresolv" != "1" ]; then
		config_get resolvfile "$cfg" resolvfile /tmp/resolv.conf.d/resolv.conf.auto
		[ -n "$resolvfile" ] && [ ! -e "$resolvfile" ] && touch "$resolvfile"
		xappend "--resolv-file=$resolvfile"
		[ "$resolvfile" = "/tmp/resolv.conf.d/resolv.conf.auto" ] && localuse=1
		resolvdir="$(dirname "$resolvfile")"
	fi
	config_get_bool localuse "$cfg" localuse "$localuse"

	config_get hostsfile "$cfg" dhcphostsfile
	[ -e "$hostsfile" ] && xappend "--dhcp-hostsfile=$hostsfile"

	local rebind
	config_get_bool rebind "$cfg" rebind_protection 1
	[ $rebind -gt 0 ] && {
		log_once \
			"DNS rebinding protection is active," \
			"will discard upstream RFC1918 responses!"
		xappend "--stop-dns-rebind"

		local rebind_localhost
		config_get_bool rebind_localhost "$cfg" rebind_localhost 0
		[ $rebind_localhost -gt 0 ] && {
			log_once "Allowing 127.0.0.0/8 responses"
			xappend "--rebind-localhost-ok"
		}

		append_rebind_domain() {
			log_once "Allowing RFC1918 responses for domain $1"
			xappend "--rebind-domain-ok=$1"
		}

		config_list_foreach "$cfg" rebind_domain append_rebind_domain
	}

	config_get_bool dnssec "$cfg" dnssec 0
	[ "$dnssec" -gt 0 ] && {
		xappend "--conf-file=$TRUSTANCHORSFILE"
		xappend "--dnssec"
		[ -x /etc/init.d/sysntpd ] && {
			if /etc/init.d/sysntpd enabled || [ "$(uci_get system.ntp.enabled)" = "1" ] ; then
				[ -f "$TIMEVALIDFILE" ] || xappend "--dnssec-no-timecheck"
			fi
		}
		config_get_bool dnsseccheckunsigned "$cfg" dnsseccheckunsigned 1
		[ "$dnsseccheckunsigned" -eq 0 ] && xappend "--dnssec-check-unsigned=no"
	}

	config_get addmac "$cfg" addmac 0
	[ "$addmac" != "0" ] && {
		[ "$addmac" = "1" ] && addmac=
		xappend "--add-mac${addmac:+="$addmac"}"
	}

	dhcp_option_add "$cfg" "" 0
	dhcp_option_add "$cfg" "" 2

	xappend "--dhcp-broadcast=tag:needs-broadcast"


	config_get dnsmasqconfdir "$cfg" confdir "/tmp/dnsmasq.d"
	xappend "--conf-dir=$dnsmasqconfdir"
	dnsmasqconfdir="${dnsmasqconfdir%%,*}"
	[ ! -d "$dnsmasqconfdir" ] && mkdir -p $dnsmasqconfdir
	xappend "--user=dnsmasq"
	xappend "--group=dnsmasq"
	echo >> $CONFIGFILE_TMP

	config_get_bool enable_tftp "$cfg" enable_tftp 0
	[ "$enable_tftp" -gt 0 ] && {
		config_get tftp_root "$cfg" tftp_root
		append EXTRA_MOUNT $tftp_root
	}

	config_foreach filter_dnsmasq host dhcp_host_add "$cfg"
	echo >> $CONFIGFILE_TMP

	config_get_bool dhcpbogushostname "$cfg" dhcpbogushostname 1
	[ "$dhcpbogushostname" -gt 0 ] && {
		xappend "--dhcp-ignore-names=tag:dhcp_bogus_hostname"
		[ -r "$DHCPBOGUSHOSTNAMEFILE" ] && xappend "--conf-file=$DHCPBOGUSHOSTNAMEFILE"
	}

	config_foreach filter_dnsmasq boot dhcp_boot_add "$cfg"
	config_foreach filter_dnsmasq mac dhcp_mac_add "$cfg"
	config_foreach filter_dnsmasq tag dhcp_tag_add "$cfg"
	config_foreach filter_dnsmasq vendorclass dhcp_vendorclass_add "$cfg"
	config_foreach filter_dnsmasq userclass dhcp_userclass_add "$cfg"
	config_foreach filter_dnsmasq circuitid dhcp_circuitid_add "$cfg"
	config_foreach filter_dnsmasq remoteid dhcp_remoteid_add "$cfg"
	config_foreach filter_dnsmasq subscrid dhcp_subscrid_add "$cfg"
	config_foreach filter_dnsmasq match dhcp_match_add "$cfg"
	config_foreach filter_dnsmasq domain dhcp_domain_add "$cfg"
	config_foreach filter_dnsmasq hostrecord dhcp_hostrecord_add "$cfg"
	[ -n "$BOOT" ] || config_foreach filter_dnsmasq relay dhcp_relay_add "$cfg"

	echo >> $CONFIGFILE_TMP
	config_foreach filter_dnsmasq srvhost dhcp_srv_add "$cfg"
	config_foreach filter_dnsmasq mxhost dhcp_mx_add "$cfg"
	echo >> $CONFIGFILE_TMP

	config_get_bool boguspriv "$cfg" boguspriv 1
	[ "$boguspriv" -gt 0 ] && {
		xappend "--bogus-priv"
		[ -r "$RFC6761FILE" ] && xappend "--conf-file=$RFC6761FILE"
	}

	if [ "$DNSMASQ_DHCP_VER" -gt 4 ] ; then
		# Enable RA feature for when/if it is constructed,
		# and RA is selected per interface pool (RA, DHCP, or both),
		# but no one (should) want RA broadcast in syslog
		[ -n "$BOOT" ] || config_foreach filter_dnsmasq dhcp dhcp_add "$cfg"
		xappend "--enable-ra"
		xappend "--quiet-ra"
		append_bool "$cfg" quietdhcp "--quiet-dhcp6"

	elif [ "$DNSMASQ_DHCP_VER" -gt 0 ] ; then
		[ -n "$BOOT" ] || config_foreach filter_dnsmasq dhcp dhcp_add "$cfg"
	fi


	echo >> $CONFIGFILE_TMP
	config_foreach filter_dnsmasq cname dhcp_cname_add "$cfg"
	echo >> $CONFIGFILE_TMP

	echo >> $CONFIGFILE_TMP
	config_foreach filter_dnsmasq ipset dnsmasq_ipset_add "$cfg"
	echo >> $CONFIGFILE_TMP

	echo >> $CONFIGFILE_TMP
	mv -f $CONFIGFILE_TMP $CONFIGFILE
	mv -f $HOSTFILE_TMP $HOSTFILE

	[ "$localuse" -gt 0 ] && {
		rm -f /tmp/resolv.conf
		[ $ADD_LOCAL_DOMAIN -eq 1 ] && [ -n "$DOMAIN" ] && {
			echo "search $DOMAIN" >> /tmp/resolv.conf
		}
		DNS_SERVERS="$DNS_SERVERS 127.0.0.1"
		[ -e /proc/sys/net/ipv6 ] && DNS_SERVERS="$DNS_SERVERS ::1"
		for DNS_SERVER in $DNS_SERVERS ; do
			echo "nameserver $DNS_SERVER" >> /tmp/resolv.conf
		done
	}

	procd_open_instance $cfg
	procd_set_param command $PROG -C $CONFIGFILE -k -x /var/run/dnsmasq/dnsmasq."${cfg}".pid
	procd_set_param file $CONFIGFILE
	[ -n "$user_dhcpscript" ] && procd_set_param env USER_DHCPSCRIPT="$user_dhcpscript"
	procd_set_param respawn

	procd_add_jail dnsmasq ubus log
	procd_add_jail_mount $CONFIGFILE $DHCPBOGUSHOSTNAMEFILE $DHCPSCRIPT $DHCPSCRIPT_DEPENDS
	procd_add_jail_mount $EXTRA_MOUNT $RFC6761FILE $TRUSTANCHORSFILE
	procd_add_jail_mount $dnsmasqconffile $dnsmasqconfdir $resolvdir $user_dhcpscript
	procd_add_jail_mount /etc/passwd /etc/group /etc/TZ /etc/hosts /etc/ethers
	procd_add_jail_mount_rw /var/run/dnsmasq/ $leasefile

	procd_close_instance
}

dnsmasq_stop()
{
	local cfg="$1"
	local noresolv resolvfile localuse=0

	config_get_bool noresolv "$cfg" noresolv 0
	config_get resolvfile "$cfg" "resolvfile"

	[ "$noresolv" = 0 ] && [ "$resolvfile" = "/tmp/resolv.conf.d/resolv.conf.auto" ] && localuse=1
	config_get_bool localuse "$cfg" localuse "$localuse"
	[ "$localuse" -gt 0 ] && ln -sf "/tmp/resolv.conf.d/resolv.conf.auto" /tmp/resolv.conf

	rm -f ${BASEDHCPSTAMPFILE}.${cfg}.*.dhcp
}

add_interface_trigger()
{
	local interface ignore

	config_get interface "$1" interface
	config_get_bool ignore "$1" ignore 0

	[ -n "$interface" ] && [ $ignore -eq 0 ] && procd_add_interface_trigger "interface.*" "$interface" /etc/init.d/dnsmasq reload
}

service_triggers()
{
	procd_add_reload_trigger "dhcp" "system"

	config_load dhcp
	config_foreach add_interface_trigger dhcp
	config_foreach add_interface_trigger relay
}

boot()
{
	BOOT=1
	start "$@"
}

start_service() {
	local instance="$1"
	local instance_found=0
	local first_instance=""

	. /lib/functions/network.sh

	config_cb() {
		local type="$1"
		local name="$2"
		if [ "$type" = "dnsmasq" ]; then
			if [ -n "$instance" ] && [ "$instance" = "$name" ]; then
				instance_found=1
			fi
			if [ -z "$DEFAULT_INSTANCE" ]; then
				local disabled
				config_get_bool disabled "$name" disabled 0
				if [ "$disabled" -eq 0 ]; then
					# First enabled section will be assigned default instance name.
					# Unnamed sections get precedence over named sections.
					if expr "$cfg" : 'cfg[0-9a-f]*$' >/dev/null = "9"; then # See uci_fixup_section.
						DEFAULT_INSTANCE="$name" # Unnamed config section.
					elif [ -z "$first_instance" ]; then
						first_instance="$name"
					fi
				fi
			fi
		fi
	}

	DEFAULT_INSTANCE=""
	config_load dhcp
	if [ -z "$DEFAULT_INSTANCE" ]; then
		DEFAULT_INSTANCE="$first_instance" # No unnamed config section was found.
	fi

	if [ -n "$instance" ]; then
		[ "$instance_found" -gt 0 ] || return
		dnsmasq_start "$instance"
	else
		config_foreach dnsmasq_start dnsmasq
	fi
}

reload_service() {
	rc_procd start_service "$@"
	procd_send_signal dnsmasq "$@"
}

stop_service() {
	local instance="$1"
	local instance_found=0

	config_cb() {
		local type="$1"
		local name="$2"
		if [ "$type" = "dnsmasq" ]; then
			if [ -n "$instance" ] && [ "$instance" = "$name" ]; then
				instance_found=1
			fi
		fi
	}

	config_load dhcp

	if [ -n "$instance" ]; then
		[ "$instance_found" -gt 0 ] || return
		dnsmasq_stop "$instance"
	else
		config_foreach dnsmasq_stop dnsmasq
	fi
}
