#
# Copyright (c) 2003 The FreeBSD Project. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
#
IFCONFIG_CMD="/sbin/ifconfig"

# Maximum number of addresses expanded from a address range specification.
_IPEXPANDMAX=31

#
# Subroutines commonly used from network startup scripts.
# Requires that rc.conf be loaded first.
#

# ifn_start ifn
#	Bring up and configure an interface.  If some configuration is
#	applied, print the interface configuration.
#
ifn_start()
{
	local ifn cfg
	ifn="$1"
	cfg=1

	[ -z "$ifn" ] && err 1 "ifn_start called without an interface"

	ifscript_up ${ifn} && cfg=0
	ifconfig_up ${ifn} && cfg=0
	afexists inet && ipv4_up ${ifn} && cfg=0
	afexists inet6 && ipv6_up ${ifn} && cfg=0
	afexists ipx && ipx_up ${ifn} && cfg=0
	childif_create ${ifn} && cfg=0

	return $cfg
}

# ifn_stop ifn
#	Shutdown and de-configure an interface.  If action is taken,
#	print the interface name.
#
ifn_stop()
{
	local ifn cfg
	ifn="$1"
	cfg=1

	[ -z "$ifn" ] && err 1 "ifn_stop called without an interface"

	afexists ipx && ipx_down ${ifn} && cfg=0
	afexists inet6 && ipv6_down ${ifn} && cfg=0
	afexists inet && ipv4_down ${ifn} && cfg=0
	ifconfig_down ${ifn} && cfg=0
	ifscript_down ${ifn} && cfg=0
	childif_destroy ${ifn} && cfg=0

	return $cfg
}

# ifconfig_up if
#	Evaluate ifconfig(8) arguments for interface $if and
#	run ifconfig(8) with those arguments. It returns 0 if
#	arguments were found and executed or 1 if the interface
#	had no arguments.  Pseudo arguments DHCP and WPA are handled
#	here.
#
ifconfig_up()
{
	local _cfg _ipv6_opts ifconfig_args
	_cfg=1

	# Make sure lo0 always comes up.
	if [ "$1" = "lo0" ]; then
		_cfg=0
	fi

	# ifconfig_IF
	ifconfig_args=`ifconfig_getargs $1`
	if [ -n "${ifconfig_args}" ]; then
		eval ${IFCONFIG_CMD} $1 ${ifconfig_args}
		_cfg=0
	fi

	# inet6 specific
	if afexists inet6; then
		if checkyesno ipv6_activate_all_interfaces; then
			_ipv6_opts="-ifdisabled"
		elif [ "$1" != "lo0" ]; then
			_ipv6_opts="ifdisabled"
		fi

		# backward compatibility: $ipv6_enable
		case $ipv6_enable in
		[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
			case $1 in
			bridge[0-9]*)
				# No accept_rtadv by default on if_bridge(4)
				# to avoid a conflict with the member
				# interfaces.
			;;
			*)
				if ! checkyesno ipv6_gateway_enable; then
					_ipv6_opts="${_ipv6_opts} accept_rtadv"
				fi
			;;
			esac
		;;
		esac

		case $ipv6_cpe_wanif in
		$1)
			_ipv6_opts="${_ipv6_opts} -no_radr accept_rtadv"
		;;
		esac

		if [ -n "${_ipv6_opts}" ]; then
			${IFCONFIG_CMD} $1 inet6 ${_ipv6_opts}
		fi

		# ifconfig_IF_ipv6
		ifconfig_args=`ifconfig_getargs $1 ipv6`
		if [ -n "${ifconfig_args}" ]; then
			# backward compatibility: inet6 keyword
			case "${ifconfig_args}" in
			:*|[0-9a-fA-F]*:*)
				warn "\$ifconfig_$1_ipv6 needs " \
				    "\"inet6\" keyword for an IPv6 address."
				ifconfig_args="inet6 ${ifconfig_args}"
			;;
			esac
			${IFCONFIG_CMD} $1 inet6 -ifdisabled
			eval ${IFCONFIG_CMD} $1 ${ifconfig_args}
			_cfg=0
		fi

		# $ipv6_prefix_IF will be handled in
		# ipv6_prefix_hostid_addr_common().
		ifconfig_args=`get_if_var $1 ipv6_prefix_IF`
		if [ -n "${ifconfig_args}" ]; then
			${IFCONFIG_CMD} $1 inet6 -ifdisabled
			_cfg=0
		fi

		# backward compatibility: $ipv6_ifconfig_IF
		ifconfig_args=`get_if_var $1 ipv6_ifconfig_IF`
		if [ -n "${ifconfig_args}" ]; then
			warn "\$ipv6_ifconfig_$1 is obsolete." \
			    "  Use ifconfig_$1_ipv6 instead."
			${IFCONFIG_CMD} $1 inet6 -ifdisabled
			eval ${IFCONFIG_CMD} $1 inet6 ${ifconfig_args}
			_cfg=0
		fi
	fi

	ifalias $1 link alias
	ifalias $1 ether alias

	if [ ${_cfg} -eq 0 ]; then
		${IFCONFIG_CMD} $1 up
	fi

	if wpaif $1; then
		/etc/rc.d/wpa_supplicant start $1
		_cfg=0		# XXX: not sure this should count
	elif hostapif $1; then
		/etc/rc.d/hostapd start $1
		_cfg=0
	fi

	if dhcpif $1; then
		if [ $_cfg -ne 0 ] ; then
			${IFCONFIG_CMD} $1 up
		fi
		if syncdhcpif $1; then
			/etc/rc.d/dhclient start $1
		fi
		_cfg=0
	fi

	return $_cfg
}

# ifconfig_down if
#	returns 1 if wpa_supplicant or dhclient was stopped or
#	the interface exists.
#
ifconfig_down()
{
	local _cfg
	_cfg=1

	if wpaif $1; then
		/etc/rc.d/wpa_supplicant stop $1
		_cfg=0
	elif hostapif $1; then
		/etc/rc.d/hostapd stop $1
		_cfg=0
	fi

	if dhcpif $1; then
		/etc/rc.d/dhclient stop $1
		_cfg=0
	fi

	if ifexists $1; then
		${IFCONFIG_CMD} $1 down
		_cfg=0
	fi

	return $_cfg
}

# get_if_var if var [default]
#	Return the value of the pseudo-hash corresponding to $if where
#	$var is a string containg the sub-string "IF" which will be
#	replaced with $if after the characters defined in _punct are
#	replaced with '_'. If the variable is unset, replace it with
#	$default if given.
get_if_var()
{
	local _if _punct _punct_c _var _default prefix suffix

	if [ $# -ne 2 -a $# -ne 3 ]; then
		err 3 'USAGE: get_if_var name var [default]'
	fi

	_if=$1
	_punct=". - / +"
	for _punct_c in $_punct; do
		_if=`ltr ${_if} ${_punct_c} '_'`
	done
	_var=$2
	_default=$3

	prefix=${_var%%IF*}
	suffix=${_var##*IF}
	eval echo \${${prefix}${_if}${suffix}-${_default}}
}

# _ifconfig_getargs if [af]
#	Prints the arguments for the supplied interface to stdout.
#	Returns 1 if empty.  In general, ifconfig_getargs should be used
#	outside this file.
_ifconfig_getargs()
{
	local _ifn _af
	_ifn=$1
	_af=${2+_$2}

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

	get_if_var $_ifn ifconfig_IF$_af "$ifconfig_DEFAULT"
}

# ifconfig_getargs if [af]
#	Takes the result from _ifconfig_getargs and removes pseudo
#	args such as DHCP and WPA.
ifconfig_getargs()
{
	local _tmpargs _arg _args
	_tmpargs=`_ifconfig_getargs $1 $2`
	if [ $? -eq 1 ]; then
		return 1
	fi
	_args=

	for _arg in $_tmpargs; do
		case $_arg in
		[Dd][Hh][Cc][Pp]) ;;
		[Nn][Oo][Aa][Uu][Tt][Oo]) ;;
		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]) ;;
		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]) ;;
		[Ww][Pp][Aa]) ;;
		[Hh][Oo][Ss][Tt][Aa][Pp]) ;;
		*)
			_args="$_args $_arg"
			;;
		esac
	done

	echo $_args
}

# autoif
#	Returns 0 if the interface should be automatically configured at
#	boot time and 1 otherwise.
autoif()
{
	local _tmpargs _arg
	_tmpargs=`_ifconfig_getargs $1`

	for _arg in $_tmpargs; do
		case $_arg in
		[Nn][Oo][Aa][Uu][Tt][Oo])
			return 1
			;;
		esac
	done

	return 0
}

# dhcpif if
#	Returns 0 if the interface is a DHCP interface and 1 otherwise.
dhcpif()
{
	local _tmpargs _arg
	_tmpargs=`_ifconfig_getargs $1`

	case $1 in
	lo[0-9]*|\
	stf[0-9]*|\
	faith[0-9]*|\
	lp[0-9]*|\
	sl[0-9]*)
		return 1
		;;
	esac
	if noafif $1; then
		return 1
	fi

	for _arg in $_tmpargs; do
		case $_arg in
		[Dd][Hh][Cc][Pp])
			return 0
			;;
		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp])
			return 0
			;;
		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp])
			return 0
			;;
		esac
	done

	return 1
}

# syncdhcpif
#	Returns 0 if the interface should be configured synchronously and
#	1 otherwise.
syncdhcpif()
{
	local _tmpargs _arg
	_tmpargs=`_ifconfig_getargs $1`

	if noafif $1; then
		return 1
	fi

	for _arg in $_tmpargs; do
		case $_arg in
		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp])
			return 1
			;;
		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp])
			return 0
			;;
		esac
	done

	checkyesno synchronous_dhclient
}

# wpaif if
#	Returns 0 if the interface is a WPA interface and 1 otherwise.
wpaif()
{
	local _tmpargs _arg
	_tmpargs=`_ifconfig_getargs $1`

	for _arg in $_tmpargs; do
		case $_arg in
		[Ww][Pp][Aa])
			return 0
			;;
		esac
	done

	return 1
}

# hostapif if
#	Returns 0 if the interface is a HOSTAP interface and 1 otherwise.
hostapif()
{
	local _tmpargs _arg
	_tmpargs=`_ifconfig_getargs $1`

	for _arg in $_tmpargs; do
		case $_arg in
		[Hh][Oo][Ss][Tt][Aa][Pp])
			return 0
			;;
		esac
	done

	return 1
}

# afexists af
#	Returns 0 if the address family is enabled in the kernel
#	1 otherwise.
afexists()
{
	local _af
	_af=$1

	case ${_af} in
	inet|inet6)
		check_kern_features ${_af}
		;;
	ipx)
		${SYSCTL_N} net.ipx > /dev/null 2>&1
		;;
	atm)
		if [ -x /sbin/atmconfig ]; then
			/sbin/atmconfig diag list > /dev/null 2>&1
		else
			return 1
		fi
		;;
	link|ether)
		return 0
		;;
	*)
		err 1 "afexists(): Unsupported address family: $_af"
		;;
	esac
}

# noafif if
#	Returns 0 if the interface has no af configuration and 1 otherwise.
noafif()
{
	local _if
	_if=$1

	case $_if in
	pflog[0-9]*|\
	pfsync[0-9]*|\
	an[0-9]*|\
	ath[0-9]*|\
	ipw[0-9]*|\
	ipfw[0-9]*|\
	iwi[0-9]*|\
	iwn[0-9]*|\
	ral[0-9]*|\
	wi[0-9]*|\
	wl[0-9]*|\
	wpi[0-9]*)
		return 0
		;;
	esac

	return 1
}

# ipv6if if
#	Returns 0 if the interface should be configured for IPv6 and
#	1 otherwise.
ipv6if()
{
	local _if _tmpargs i
	_if=$1

	if ! afexists inet6; then
		return 1
	fi

	# lo0 is always IPv6-enabled
	case $_if in
	lo0)
		return 0
		;;
	esac

	case "${ipv6_network_interfaces}" in
	$_if|"$_if "*|*" $_if"|*" $_if "*|[Aa][Uu][Tt][Oo])
		# True if $ifconfig_IF_ipv6 is defined.
		_tmpargs=`_ifconfig_getargs $_if ipv6`
		if [ -n "${_tmpargs}" ]; then
			return 0
		fi

		# True if $ipv6_prefix_IF is defined.
		_tmpargs=`get_if_var $_if ipv6_prefix_IF`
		if [ -n "${_tmpargs}" ]; then
			return 0
		fi

		# backward compatibility: True if $ipv6_ifconfig_IF is defined.
		_tmpargs=`get_if_var $_if ipv6_ifconfig_IF`
		if [ -n "${_tmpargs}" ]; then
			return 0
		fi
		;;
	esac

	return 1
}

# ipv6_autoconfif if
#	Returns 0 if the interface should be configured for IPv6 with
#	Stateless Address Configuration; 1 otherwise.
ipv6_autoconfif()
{
	local _if _tmpargs _arg
	_if=$1

	case $_if in
	lo[0-9]*|\
	stf[0-9]*|\
	faith[0-9]*|\
	lp[0-9]*|\
	sl[0-9]*)
		return 1
		;;
	esac
	if noafif $_if; then
		return 1
	fi
	if ! ipv6if $_if; then
		return 1
	fi
	if checkyesno ipv6_gateway_enable; then
		return 1
	fi
	_tmpargs=`get_if_var $_if ipv6_prefix_IF`
	if [ -n "${_tmpargs}" ]; then
		return 1
	fi
	# backward compatibility: $ipv6_enable
	case $ipv6_enable in
	[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
		if checkyesno ipv6_gateway_enable; then
			return 1
		fi
		case $1 in
		bridge[0-9]*)
			# No accept_rtadv by default on if_bridge(4)
			# to avoid a conflict with the member
			# interfaces.
			return 1
		;;
		*)
			return 0
		;;
		esac
	;;
	esac

	_tmpargs=`_ifconfig_getargs $_if ipv6`
	for _arg in $_tmpargs; do
		case $_arg in
		accept_rtadv)
			return 0
			;;
		esac
	done

	# backward compatibility: $ipv6_ifconfig_IF
	_tmpargs=`get_if_var $_if ipv6_ifconfig_IF`
	for _arg in $_tmpargs; do
		case $_arg in
		accept_rtadv)
			return 0
			;;
		esac
	done

	return 1
}

# ifexists if
#	Returns 0 if the interface exists and 1 otherwise.
ifexists()
{
	[ -z "$1" ] && return 1
	${IFCONFIG_CMD} -n $1 > /dev/null 2>&1
}

# ipv4_up if
#	add IPv4 addresses to the interface $if
ipv4_up()
{
	local _if _ret
	_if=$1
	_ret=1

	# Add 127.0.0.1/8 to lo0 unless otherwise specified.
	if [ "${_if}" = "lo0" ]; then
		ifconfig_args=`get_if_var ${_if} ifconfig_IF`
		if [ -z "${ifconfig_args}" ]; then
			${IFCONFIG_CMD} ${_if} inet 127.0.0.1/8 alias
		fi
	fi
	ifalias ${_if} inet alias && _ret=0

	return $_ret
}

# ipv6_up if
#	add IPv6 addresses to the interface $if
ipv6_up()
{
	local _if _ret
	_if=$1
	_ret=1

	if ! ipv6if $_if; then
		return 0
	fi

	ifalias ${_if} inet6 alias && _ret=0
	ipv6_prefix_hostid_addr_common ${_if} alias && _ret=0
	ipv6_accept_rtadv_up ${_if} && _ret=0

	return $_ret
}

# ipv4_down if
#	remove IPv4 addresses from the interface $if
ipv4_down()
{
	local _if _ifs _ret inetList oldifs _inet
	_if=$1
	_ifs="^"
	_ret=1

	ifalias ${_if} inet -alias && _ret=0

	inetList="`${IFCONFIG_CMD} ${_if} | grep 'inet ' | tr "\n" "$_ifs"`"

	oldifs="$IFS"
	IFS="$_ifs"
	for _inet in $inetList ; do
		# get rid of extraneous line
		case $_inet in
		"")				break ;;
		\	inet\ *|inet\ *)	;;
		*)				continue ;;
		esac
		[ -z "$_inet" ] && break

		_inet=`expr "$_inet" : '.*\(inet \([0-9]\{1,3\}\.\)\{3\}[0-9]\{1,3\}\).*'`

		IFS="$oldifs"
		${IFCONFIG_CMD} ${_if} ${_inet} delete
		IFS="$_ifs"
		_ret=0
	done
	IFS="$oldifs"

	return $_ret
}

# ipv6_down if
#	remove IPv6 addresses from the interface $if
ipv6_down()
{
	local _if _ifs _ret inetList oldifs _inet6
	_if=$1
	_ifs="^"
	_ret=1

	if ! ipv6if $_if; then
		return 0
	fi

	ipv6_accept_rtadv_down ${_if} && _ret=0
	ipv6_prefix_hostid_addr_common ${_if} -alias && _ret=0
	ifalias ${_if} inet6 -alias && _ret=0

	inetList="`${IFCONFIG_CMD} ${_if} | grep 'inet6 ' | tr "\n" "$_ifs"`"

	oldifs="$IFS"
	IFS="$_ifs"
	for _inet6 in $inetList ; do
		# get rid of extraneous line
		[ -z "$_inet6" ] && break

		_inet6=`expr "$_inet6" : '.*\(inet6 \([0-9a-f:]*\)\).*'`

		IFS="$oldifs"
		${IFCONFIG_CMD} ${_if} ${_inet6} -alias
		IFS="$_ifs"
		_ret=0
	done
	IFS="$oldifs"

	return $_ret
}

# ifalias if af action
#	Configure or remove aliases for network interface $if.
#	It returns 0 if at least one alias was configured or
#	removed, or 1 if there were none.
#
ifalias()
{
	local _ret
	_ret=1

	afexists $2 || return $_ret

	case "$2" in
	inet|inet6|link|ether)
		ifalias_af_common $1 $2 $3 && _ret=0
		;;
	esac

	return $_ret
}

# ifalias_expand_addr af action addr
#	Expand address range ("N-M") specification in addr.
#	"addr" must not include an address-family keyword.
#	The results will include an address-family keyword.
#
ifalias_expand_addr()
{
	local _af _action

	_af=$1
	_action=$2
	shift 2

	afexists $_af || return
	ifalias_expand_addr_$_af $_action $*
}

# ifalias_expand_addr_inet action addr
#	Helper function for ifalias_expand_addr().  Handles IPv4.
#
ifalias_expand_addr_inet()
{
	local _action _arg _cidr _cidr_addr _exargs
	local _ipaddr _plen _range _iphead _iptail _iplow _iphigh _ipcount
	local _retstr _c
	_action=$1
	_arg=$2
	shift 2
	_exargs=$*
	_retstr=

	case $_action:$_arg:$_exargs in
	*:*--*)		return ;;	# invalid
	tmp:*[0-9]-[0-9]*:*)		# to be expanded
		_action="alias"
	;;
	*:*[0-9]-[0-9]*:*)		# to be expanded
	;;
	tmp:*:*netmask*)		# already expanded w/ netmask option
		echo ${_arg%/[0-9]*} $_exargs && return
	;;
	tmp:*:*)			# already expanded w/o netmask option
		echo $_arg $_exargs && return
	;;
	*:*:*netmask*)			# already expanded w/ netmask option
		echo inet ${_arg%/[0-9]*} $_exargs && return
	;;
	*:*:*)				# already expanded w/o netmask option
		echo inet $_arg $_exargs && return
	;;
	esac

	for _cidr in $_arg; do
		_ipaddr=${_cidr%%/*}
		_plen=${_cidr##*/}
		# When subnet prefix length is not specified, use /32.
		case $_plen in
		$_ipaddr)	_plen=32 ;;	# "/" character not found
		esac

		OIFS=$IFS
		IFS=. set -- $_ipaddr
		_range=
		_iphead=
		_iptail=
		for _c in $@; do
			case $_range:$_c in
			:[0-9]*-[0-9]*)
				_range=$_c
			;;
			:*)
				_iphead="${_iphead}${_iphead:+.}${_c}"
			;;
			*:*)
				_iptail="${_iptail}${_iptail:+.}${_c}"
			;;
			esac
		done
		IFS=$OIFS
		_iplow=${_range%-*}
		_iphigh=${_range#*-}

		# clear netmask when removing aliases
		if [ "$_action" = "-alias" ]; then
			_plen=""
		fi

		_ipcount=$_iplow
		while [ "$_ipcount" -le "$_iphigh" ]; do
			_retstr="${_retstr} ${_iphead}${_iphead:+.}${_ipcount}${_iptail:+.}${_iptail}${_plen:+/}${_plen}"
			if [ $_ipcount -gt $(($_iplow + $_IPEXPANDMAX)) ]; then
				warn "Range specification is too large (${_iphead}${_iphead:+.}${_iplow}${_iptail:+.}${_iptail}-${_iphead}${_iphead:+.}${_iphigh}${_iptail:+.}${_iptail}).  ${_iphead}${_iphead:+.}${_iplow}${_iptail:+.}${_iptail}-${_iphead}${_iphead:+.}${_ipcount}${_iptail:+.}${_iptail} was processed."
				break
			else
				_ipcount=$(($_ipcount + 1))
			fi
			# Forcibly set /32 for remaining aliases.
			_plen=32
		done
	done

	for _c in $_retstr; do
		ifalias_expand_addr_inet $_action $_c $_exargs
	done
}

# ifalias_expand_addr_inet6 action addr
#	Helper function for ifalias_expand_addr().  Handles IPv6.
#
ifalias_expand_addr_inet6()
{
	local _action _arg _cidr _cidr_addr _exargs
	local _ipaddr _plen _ipleft _ipright _iplow _iphigh _ipcount
	local _ipv4part
	local _retstr _c
	_action=$1
	_arg=$2
	shift 2
	_exargs=$*
	_retstr=

	case $_action:$_arg:$_exargs in
	*:*--*:*)	return ;;	# invalid
	tmp:*[0-9a-zA-Z]-[0-9a-zA-Z]*:*)# to be expanded
		_action="alias"
	;;
	*:*[0-9a-zA-Z]-[0-9a-zA-Z]*:*)	# to be expanded
	;;
	tmp:*:*prefixlen*)	# already expanded w/ prefixlen option
		echo ${_arg%/[0-9]*} $_exargs && return
	;;
	tmp:*:*)		# already expanded w/o prefixlen option
		echo $_arg $_exargs && return
	;;
	*:*:*prefixlen*)	# already expanded w/ prefixlen option
		echo inet6 ${_arg%/[0-9]*} $_exargs && return
	;;
	*:*:*)			# already expanded w/o prefixlen option
		echo inet6 $_arg $_exargs && return
	;;
	esac

	for _cidr in $_arg; do
		_ipaddr="${_cidr%%/*}"
		_plen="${_cidr##*/}"

		case $_action:$_ipaddr:$_cidr in
		-alias:*:*)		unset _plen ;;
		*:$_cidr:$_ipaddr)	unset _plen ;;
		esac

		if [ "${_ipaddr%:*.*.*.*}" = "$_ipaddr" ]; then
			# Handle !v4mapped && !v4compat addresses.

			# The default prefix length is 64.
			case $_ipaddr:$_cidr in
			$_cidr:$_ipaddr)	_plen="64" ;;
			esac
			_ipleft=${_ipaddr%-*}
			_ipright=${_ipaddr#*-}
			_iplow=${_ipleft##*:}
			_iphigh=${_ipright%%:*}
			_ipleft=${_ipleft%:*}
			_ipright=${_ipright#*:}

			if [ "$_iphigh" = "$_ipright" ]; then
				unset _ipright
			else
				_ipright=:$_ipright
			fi

			if [ -n "$_iplow" -a -n "$_iphigh" ]; then
				_iplow=$((0x$_iplow))
				_iphigh=$((0x$_iphigh))
				_ipcount=$_iplow
				while [ $_ipcount -le $_iphigh ]; do
					_r=`printf "%s:%04x%s%s" \
					    $_ipleft $_ipcount $_ipright \
					    ${_plen:+/}$_plen`
					_retstr="$_retstr $_r"
					if [ $_ipcount -gt $(($_iplow + $_IPEXPANDMAX)) ]
					then
						warn "Range specification is too large $(printf '(%s:%04x%s-%s:%04x%s)' $_ipleft $_iplow $_ipright $_ipleft $_iphigh $_ipright). $(printf '%s:%04x%s-%s:%04x%s' $_ipleft $_iplow $_ipright $_ipleft $_ipcount $_ipright) was processed."
						break
					else
						_ipcount=$(($_ipcount + 1))
					fi
				done
			else
				_retstr="${_ipaddr}${_plen:+/}${_plen}"
			fi

			for _c in $_retstr; do
				ifalias_expand_addr_inet6 $_action $_c $_exargs
			done
		else
			# v4mapped/v4compat should handle as an IPv4 alias
			_ipv4part=${_ipaddr##*:}

			# Adjust prefix length if any.  If not, set the
			# default prefix length as 32.
			case $_ipaddr:$_cidr in
			$_cidr:$_ipaddr)	_plen=32 ;;
			*)			_plen=$(($_plen - 96)) ;;
			esac

			_retstr=`ifalias_expand_addr_inet \
			    tmp ${_ipv4part}${_plen:+/}${_plen}`
			for _c in $_retstr; do
				ifalias_expand_addr_inet $_action $_c $_exargs
			done
		fi
	done
}

# ifalias_af_common_handler if af action args
#	Helper function for ifalias_af_common().
#
ifalias_af_common_handler()
{
	local _ret _if _af _action _args _c _tmpargs

	_ret=1
	_if=$1
	_af=$2
	_action=$3
	shift 3
	_args=$*

	case $_args in
	${_af}\ *)	;;
	*)	return	;;
	esac

	# link(ether) does not support address removal.
	case $_af:$_action in
	link:-alias|ether:-alias)	return ;;
	esac

	_tmpargs=
	for _c in $_args; do
		case $_c in
		${_af})
			case $_tmpargs in
			${_af}\ *-*)
				ifalias_af_common_handler $_if $_af $_action \
				`ifalias_expand_addr $_af $_action ${_tmpargs#${_af}\ }`
			;;
			${_af}\ *)
				${IFCONFIG_CMD} $_if $_tmpargs $_action && _ret=0
			;;
			esac
			_tmpargs=$_af
		;;
		*)
			_tmpargs="$_tmpargs $_c"
		;;
		esac
	done
	# Process the last component if any.
	if [ -n "$_tmpargs}" ]; then
		case $_tmpargs in
		${_af}\ *-*)
			ifalias_af_common_handler $_if $_af $_action \
			`ifalias_expand_addr $_af $_action ${_tmpargs#${_af}\ }`
		;;
		${_af}\ *)
			${IFCONFIG_CMD} $_if $_tmpargs $_action && _ret=0
		;;
		esac
	fi

	return $_ret
}

# ifalias_af_common if af action
#	Helper function for ifalias().
#
ifalias_af_common()
{
	local _ret _if _af _action alias ifconfig_args _aliasn _c _tmpargs _iaf

	_ret=1
	_aliasn=
	_if=$1
	_af=$2
	_action=$3

	# ifconfig_IF_aliasN which starts with $_af
	alias=0
	while : ; do
		ifconfig_args=`get_if_var $_if ifconfig_IF_alias${alias}`
		_iaf=
		case $ifconfig_args in
		inet\ *)	_iaf=inet ;;
		inet6\ *)	_iaf=inet6 ;;
		ipx\ *)		_iaf=ipx ;;
		link\ *)	_iaf=link ;;
		ether\ *)	_iaf=ether ;;
		esac

		case ${_af}:${_action}:${_iaf}:"${ifconfig_args}" in
		${_af}:*:${_af}:*)
			_aliasn="$_aliasn $ifconfig_args"
			;;
		${_af}:*:"":"")
			break
			;;
		inet:alias:"":*)
			_aliasn="$_aliasn inet $ifconfig_args"
			warn "\$ifconfig_${_if}_alias${alias} needs " \
			    "\"inet\" keyword for an IPv4 address."
		esac
		alias=$(($alias + 1))
	done

	# backward compatibility: ipv6_ifconfig_IF_aliasN.
	case $_af in
	inet6)
		alias=0
		while : ; do
			ifconfig_args=`get_if_var $_if ipv6_ifconfig_IF_alias${alias}`
			case ${_action}:"${ifconfig_args}" in
			*:"")
				break
			;;
			alias:*)
				_aliasn="${_aliasn} inet6 ${ifconfig_args}"
				warn "\$ipv6_ifconfig_${_if}_alias${alias} " \
				    "is obsolete.  Use ifconfig_$1_aliasN " \
				    "instead."
			;;
			esac
			alias=$(($alias + 1))
		done
	esac

	# backward compatibility: ipv4_addrs_IF.
	for _tmpargs in `get_if_var $_if ipv4_addrs_IF`; do
		_aliasn="$_aliasn inet $_tmpargs"
	done

	# Handle ifconfig_IF_aliases, ifconfig_IF_aliasN, and the others.
	_tmpargs=
	for _c in `get_if_var $_if ifconfig_IF_aliases` $_aliasn; do
		case $_c in
		inet|inet6|ipx|link|ether)
			case $_tmpargs in
			${_af}\ *)
				eval ifalias_af_common_handler $_if $_af $_action $_tmpargs && _ret=0
			;;
			esac
			_tmpargs=$_c
		;;
		*)
			_tmpargs="$_tmpargs $_c"
		esac
	done
	# Process the last component
	case $_tmpargs in
	${_af}\ *)
		ifalias_af_common_handler $_if $_af $_action $_tmpargs && _ret=0
	;;
	esac

	return $_ret
}

# ipv6_prefix_hostid_addr_common if action
#	Add or remove IPv6 prefix + hostid addr on the interface $if
#
ipv6_prefix_hostid_addr_common()
{
	local _if _action prefix j
	_if=$1
	_action=$2
	prefix=`get_if_var ${_if} ipv6_prefix_IF`

	if [ -n "${prefix}" ]; then
		for j in ${prefix}; do
			# The default prefixlen is 64.
			plen=${j#*/}
			case $j:$plen in
			$plen:$j)	plen=64 ;;
			*)		j=${j%/*} ;;
			esac

			# Normalize the last part by removing ":"
			j=${j%::*}
			j=${j%:}
			${IFCONFIG_CMD} ${_if} inet6 $j:: \
				prefixlen $plen eui64 ${_action}

			# if I am a router, add subnet router
			# anycast address (RFC 2373).
			if checkyesno ipv6_gateway_enable; then
				${IFCONFIG_CMD} ${_if} inet6 $j:: \
					prefixlen $plen ${_action} anycast
			fi
		done
	fi
}

# ipv6_accept_rtadv_up if
#	Enable accepting Router Advertisement and send Router
#	Solicitation message
ipv6_accept_rtadv_up()
{
	if ipv6_autoconfif $1; then
		${IFCONFIG_CMD} $1 inet6 accept_rtadv up
		if ! checkyesno rtsold_enable; then
			rtsol ${rtsol_flags} $1
		fi
	fi
}

# ipv6_accept_rtadv_down if
#	Disable accepting Router Advertisement
ipv6_accept_rtadv_down()
{
	if ipv6_autoconfif $1; then
		${IFCONFIG_CMD} $1 inet6 -accept_rtadv
	fi
}

# ifscript_up if
#	Evaluate a startup script for the $if interface.
#	It returns 0 if a script was found and processed or
#	1 if no script was found.
#
ifscript_up()
{
	if [ -r /etc/start_if.$1 ]; then
		. /etc/start_if.$1
		return 0
	else
		return 1
	fi
}

# ifscript_down if
#	Evaluate a shutdown script for the $if interface.
#	It returns 0 if a script was found and processed or
#	1 if no script was found.
#
ifscript_down()
{
	if [ -r /etc/stop_if.$1 ]; then
		. /etc/stop_if.$1
		return 0
	else
		return 1
	fi
}

# clone_up
#	Create cloneable interfaces.
#
clone_up()
{
	local _prefix _list ifn ifopt _iflist _n tmpargs
	_prefix=
	_list=
	_iflist=$*

	# create_args_IF
	for ifn in ${cloned_interfaces}; do
		# Parse ifn:ifopt.
		OIFS=$IFS; IFS=:; set -- $ifn; ifn=$1; ifopt=$2; IFS=$OIFS
		case $_iflist in
		""|$ifn|$ifn\ *|*\ $ifn\ *|*\ $ifn)	;;
		*)	continue ;;
		esac
		# Skip if ifn already exists.
		if ${IFCONFIG_CMD} $ifn > /dev/null 2>&1; then
			continue
		fi
		${IFCONFIG_CMD} ${ifn} create `get_if_var ${ifn} create_args_IF`
		if [ $? -eq 0 ]; then
			_list="${_list}${_prefix}${ifn}"
			[ -z "$_prefix" ] && _prefix=' '
		fi
	done
	if [ -n "$gif_interfaces" ]; then
		warn "\$gif_interfaces is obsolete.  Use \$cloned_interfaces instead."
	fi
	for ifn in ${gif_interfaces}; do
		# Parse ifn:ifopt.
		OIFS=$IFS; IFS=:; set -- $ifn; ifn=$1; ifopt=$2; IFS=$OIFS
		case $_iflist in
		""|$ifn|$ifn\ *|*\ $ifn\ *|*\ $ifn)	;;
		*)	continue ;;
		esac
		# Skip if ifn already exists.
		if ${IFCONFIG_CMD} $ifn > /dev/null 2>&1; then
			continue
		fi
		case $ifn in
		gif[0-9]*)
			${IFCONFIG_CMD} $ifn create
		;;
		*)
			_n=$(${IFCONFIG_CMD} gif create)
			${IFCONFIG_CMD} $_n name $ifn
		;;
		esac
		if [ $? -eq 0 ]; then
			_list="${_list}${_prefix}${ifn}"
			[ -z "$_prefix" ] && _prefix=' '
		fi
		tmpargs=$(get_if_var $ifn gifconfig_IF)
		eval ifconfig_${ifn}=\"tunnel \$tmpargs\"
	done
	if [ -n "${_list}" ]; then
		echo "Created clone interfaces: ${_list}."
	fi
	debug "Cloned: ${_list}"
}

# clone_down
#	Destroy cloned interfaces. Destroyed interfaces are echoed to
#	standard output.
#
clone_down()
{
	local _prefix _list ifn ifopt _iflist _sticky
	_prefix=
	_list=
	_iflist=$*

	: ${cloned_interfaces_sticky:=NO}
	if checkyesno cloned_interfaces_sticky; then
		_sticky=1
	else
		_sticky=0
	fi
	for ifn in ${cloned_interfaces} ${gif_interfaces}; do
		# Parse ifn:ifopt.
		OIFS=$IFS; IFS=:; set -- $ifn; ifn=$1; ifopt=$2; IFS=$OIFS
		case $ifopt:$_sticky in
		sticky:*)	continue ;;	# :sticky => not destroy
		nosticky:*)	;;		# :nosticky => destroy
		*:1)		continue ;;	# global sticky knob == 1
		esac
		case $_iflist in
		""|$ifn|$ifn\ *|*\ $ifn\ *|*\ $ifn)	;;
		*)	continue ;;
		esac
		# Skip if ifn does not exist.
		if ! ${IFCONFIG_CMD} $ifn > /dev/null 2>&1; then
			continue
		fi
		${IFCONFIG_CMD} -n ${ifn} destroy
		if [ $? -eq 0 ]; then
			_list="${_list}${_prefix}${ifn}"
			[ -z "$_prefix" ] && _prefix=' '
		fi
	done
	if [ -n "${_list}" ]; then
		echo "Destroyed clone interfaces: ${_list}."
	fi
	debug "Destroyed clones: ${_list}"
}

# childif_create
#	Create and configure child interfaces.  Return 0 if child
#	interfaces are created.
#
childif_create()
{
	local cfg child child_vlans child_wlans create_args debug_flags ifn i
	cfg=1
	ifn=$1

	# Create wireless interfaces
	child_wlans=`get_if_var $ifn wlans_IF`

	for child in ${child_wlans}; do
		create_args="wlandev $ifn `get_if_var $child create_args_IF`"
		debug_flags="`get_if_var $child wlandebug_IF`"

		if expr $child : 'wlan[0-9][0-9]*$' >/dev/null 2>&1; then
			${IFCONFIG_CMD} $child create ${create_args} && cfg=0
			if [ -n "${debug_flags}" ]; then
				wlandebug -i $child ${debug_flags}
			fi
		else
			i=`${IFCONFIG_CMD} wlan create ${create_args}`
			if [ -n "${debug_flags}" ]; then
				wlandebug -i $i ${debug_flags}
			fi
			${IFCONFIG_CMD} $i name $child && cfg=0
		fi
		if autoif $child; then
			ifn_start $child
		fi
	done

	# Create vlan interfaces
	child_vlans=`get_if_var $ifn vlans_IF`

	if [ -n "${child_vlans}" ]; then
		load_kld if_vlan
	fi

	for child in ${child_vlans}; do
		if expr $child : '[1-9][0-9]*$' >/dev/null 2>&1; then
			child="${ifn}.${child}"
			create_args=`get_if_var $child create_args_IF`
			${IFCONFIG_CMD} $child create ${create_args} && cfg=0
		else
			create_args="vlandev $ifn `get_if_var $child create_args_IF`"
			if expr $child : 'vlan[0-9][0-9]*$' >/dev/null 2>&1; then
				${IFCONFIG_CMD} $child create ${create_args} && cfg=0
			else
				i=`${IFCONFIG_CMD} vlan create ${create_args}`
				${IFCONFIG_CMD} $i name $child && cfg=0
			fi
		fi
		if autoif $child; then
			ifn_start $child
		fi
	done

	return ${cfg}
}

# childif_destroy
#	Destroy child interfaces.
#
childif_destroy()
{
	local cfg child child_vlans child_wlans ifn
	cfg=1

	child_wlans=`get_if_var $ifn wlans_IF`
	for child in ${child_wlans}; do
		if ! ifexists $child; then
			continue
		fi
		${IFCONFIG_CMD} -n $child destroy && cfg=0
	done

	child_vlans=`get_if_var $ifn vlans_IF`
	for child in ${child_vlans}; do
		if expr $child : '[1-9][0-9]*$' >/dev/null 2>&1; then
			child="${ifn}.${child}"
		fi
		if ! ifexists $child; then
			continue
		fi
		${IFCONFIG_CMD} -n $child destroy && cfg=0
	done

	return ${cfg}
}

# ng_mkpeer
#	Create netgraph nodes.
#
ng_mkpeer()
{
	ngctl -f - 2> /dev/null <<EOF
mkpeer $*
msg dummy nodeinfo
EOF
}

# ng_create_one
#	Create netgraph nodes.
#
ng_create_one()
{
	local t

	ng_mkpeer $* | while read line; do
		t=`expr "${line}" : '.* name="\([a-z]*[0-9]*\)" .*'`
		if [ -n "${t}" ]; then
			echo ${t}
			return
		fi
	done
}

# ng_fec_create ifn
#	Configure Fast EtherChannel for interface $ifn. Returns 0 if
#	FEC arguments were found and configured; returns !0 otherwise.
ng_fec_create()
{
	 local req_iface iface bogus
	 req_iface="$1"

	 ngctl shutdown ${req_iface}: > /dev/null 2>&1

	 bogus=""
	 while true; do
		 iface=`ng_create_one fec dummy fec`
		 if [ -z "${iface}" ]; then
			 exit 2
		 fi
		 if [ "${iface}" = "${req_iface}" ]; then
			 break
		 fi
		 bogus="${bogus} ${iface}"
	 done

	 for iface in ${bogus}; do
		 ngctl shutdown ${iface}:
	 done
}

# fec_up
#	Create Fast EtherChannel interfaces.
fec_up()
{
	local i j

	for i in ${fec_interfaces}; do
		ng_fec_create $i
		for j in `get_if_var $i fecconfig_IF`; do
			case ${j} in
			'')
				continue
				;;
			*)
				ngctl msg ${i}: add_iface "\"${j}\""
				;;
			esac
		done
	done
}

# ipx_up ifn
#	Configure any IPX addresses for interface $ifn. Returns 0 if
#	IPX arguments were found and configured; returns 1 otherwise.
#
ipx_up()
{
	local ifn
	ifn="$1"

	# ifconfig_IF_ipx
	ifconfig_args=`_ifconfig_getargs $ifn ipx`
	if [ -n "${ifconfig_args}" ]; then
		${IFCONFIG_CMD} ${ifn} ${ifconfig_args}
		return 0
	fi

	return 1
}

# ipx_down ifn
#	Remove IPX addresses for interface $ifn. Returns 0 if IPX
#	addresses were found and unconfigured. It returns 1, otherwise.
#
ipx_down()
{
	local _if _ifs _ret ipxList oldifs _ipx
	_if=$1
	_ifs="^"
	_ret=1
	ipxList="`${IFCONFIG_CMD} ${_if} | grep 'ipx ' | tr "\n" "$_ifs"`"
	oldifs="$IFS"

	IFS="$_ifs"
	for _ipx in $ipxList ; do
		# get rid of extraneous line
		[ -z "$_ipx" ] && break

		_ipx=`expr "$_ipx" : '.*\(ipx [0-9a-h]\{1,8\}H*\.[0-9a-h]\{1,12\}\).*'`

		IFS="$oldifs"
		${IFCONFIG_CMD} ${_if} ${_ipx} delete
		IFS="$_ifs"
		_ret=0
	done
	IFS="$oldifs"

	return $_ret
}

# ifnet_rename [ifname]
#	Rename interfaces if ifconfig_IF_name is defined.
#
ifnet_rename()
{
	local _if _ifname

	# ifconfig_IF_name
	for _if in ${*:-$(${IFCONFIG_CMD} -l)}; do
		_ifname=`get_if_var $_if ifconfig_IF_name`
		if [ ! -z "$_ifname" ]; then
			${IFCONFIG_CMD} $_if name $_ifname
		fi
	done

	return 0
}

# list_net_interfaces type
#	List all network interfaces. The type of interface returned
#	can be controlled by the type argument. The type
#	argument can be any of the following:
#		nodhcp	- all interfaces, excluding DHCP configured interfaces
#		dhcp	- list only DHCP configured interfaces
#		noautoconf	- all interfaces, excluding IPv6 Stateless
#				  Address Autoconf configured interfaces
#		autoconf	- list only IPv6 Stateless Address Autoconf
#				  configured interfaces
#	If no argument is specified all network interfaces are output.
#	Note that the list will include cloned interfaces if applicable.
#	Cloned interfaces must already exist to have a chance to appear
#	in the list if ${network_interfaces} is set to `auto'.
#
list_net_interfaces()
{
	local type _tmplist _list _autolist _lo _if
	type=$1

	# Get a list of ALL the interfaces and make lo0 first if it's there.
	#
	_tmplist=
	case ${network_interfaces} in
	[Aa][Uu][Tt][Oo])
		_autolist="`${IFCONFIG_CMD} -l`"
		_lo=
		for _if in ${_autolist} ; do
			if autoif $_if; then
				if [ "$_if" = "lo0" ]; then
					_lo="lo0 "
				else
					_tmplist="${_tmplist} ${_if}"
				fi
			fi
		done
		_tmplist="${_lo}${_tmplist# }"
		;;
	*)
		_tmplist="${network_interfaces} ${cloned_interfaces}"

		# lo0 is effectively mandatory, so help prevent foot-shooting
		#
		case "$_tmplist" in
		lo0|'lo0 '*|*' lo0'|*' lo0 '*) ;; # This is fine, do nothing
		*)	_tmplist="lo0 ${_tmplist}" ;;
		esac
		;;
	esac

	_list=
	case "$type" in
	nodhcp)
		for _if in ${_tmplist} ; do
			if ! dhcpif $_if && \
			   [ -n "`_ifconfig_getargs $_if`" ]; then
				_list="${_list# } ${_if}"
			fi
		done
		;;
	dhcp)
		for _if in ${_tmplist} ; do
			if dhcpif $_if; then
				_list="${_list# } ${_if}"
			fi
		done
		;;
	noautoconf)
		for _if in ${_tmplist} ; do
			if ! ipv6_autoconfif $_if && \
			   [ -n "`_ifconfig_getargs $_if ipv6`" ]; then
				_list="${_list# } ${_if}"
			fi
		done
		;;
	autoconf)
		for _if in ${_tmplist} ; do
			if ipv6_autoconfif $_if; then
				_list="${_list# } ${_if}"
			fi
		done
		;;
	*)
		_list=${_tmplist}
		;;
	esac

	echo $_list

	return 0
}

# get_default_if -address_family
#	Get the interface of the default route for the given address family.
#	The -address_family argument must be suitable passing to route(8).
#
get_default_if()
{
	local routeget oldifs defif line
	defif=
	oldifs="$IFS"
	IFS="
"
	for line in `route -n get $1 default 2>/dev/null`; do
		case $line in
		*interface:*)
			defif=${line##*: }
			;;
		esac
	done
	IFS=${oldifs}

	echo $defif
}

# hexdigit arg
#	Echo decimal number $arg (single digit) in hexadecimal format.
hexdigit()
{
	printf '%x\n' "$1"
}

# hexprint arg
#	Echo decimal number $arg (multiple digits) in hexadecimal format.
hexprint()
{
	printf '%x\n' "$1"
}

is_wired_interface()
{
	local media

	case `${IFCONFIG_CMD} $1 2>/dev/null` in
	*media:?Ethernet*) media=Ethernet ;;
	esac

	test "$media" = "Ethernet"
}

# network6_getladdr if [flag]
#	Echo link-local address from $if if any.
#	If flag is defined, tentative ones will be excluded.
network6_getladdr()
{
	local _if _flag proto addr rest
	_if=$1
	_flag=$2

	${IFCONFIG_CMD} $_if 2>/dev/null | while read proto addr rest; do
		case "${proto}/${addr}/${_flag}/${rest}" in
		inet6/fe80::*//*)
			echo ${addr}
		;;
		inet6/fe80:://*tentative*)	# w/o flag
			sleep `${SYSCTL_N} net.inet6.ip6.dad_count`
			network6_getladdr $_if $_flags
		;;
		inet6/fe80::/*/*tentative*)	# w/ flag
			echo ${addr}
		;;
		*)
			continue
		;;
		esac

		return
	done
}