freebsd/etc/network.subr

#
# 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.
#
# $FreeBSD$
#

#
# 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
	ipv4_up ${ifn} && cfg=0
	ipv6_up ${ifn} && cfg=0
	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"

	ipx_down ${ifn} && cfg=0
	ipv6_down ${ifn} && cfg=0
	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

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

	# inet6 specific
	if afexists inet6; then
		if ipv6if $1; then
			# Implicitly handles ipv6_gateway_enable
			_ipv6_opts='-ifdisabled -accept_rtadv'

			if ipv6_autoconfif $1; then
				_ipv6_opts='-ifdisabled accept_rtadv'
			fi

			ifconfig $1 inet6 $_ipv6_opts

			# ifconfig_IF_ipv6
			ifconfig_args=`ifconfig_getargs $1 ipv6`

			if [ -n "$ifconfig_args" ]; then
				ifconfig $1 $ifconfig_args
				_cfg=0
			fi
		else
		# Remove in FreeBSD 10.x
		# Explicit test is necessary here to avoid nonexistence error
			case "$ipv6_enable" in
			[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
			warn "Interface $1 will NOT be configured for IPv6"
				;;
			esac

			ifconfig $1 inet6 ifdisabled
		fi
	fi

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

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

	if dhcpif $1; then
		if [ $_cfg -ne 0 ] ; then
			ifconfig $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
	fi

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

	if ifexists $1; then
		ifconfig $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]
#	Echos 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 value
	_ifn=$1
	_af=${2+_$2}

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

	value=`get_if_var $_ifn ifconfig_IF$_af "$ifconfig_DEFAULT"`

	# Remove in FreeBSD 10.x
	if [ "$_af" = _ipv6 -a -z "$value" ]; then
		value=`get_if_var $_ifn ipv6_ifconfig_IF "$ifconfig_DEFAULT"`
		if [ -n "$value" ]; then
			warn "\$ipv6_ifconfig_$1 is obsolete." \
			"  Use ifconfig_$1_ipv6 instead."
		fi
	fi

	echo $value
}

# 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 $_arg in
		[Dd][Hh][Cc][Pp]) ;;
		[Nn][Oo][Aa][Uu][Tt][Oo]) ;;
		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]) ;;
		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]) ;;
		[Ww][Pp][Aa]) ;;
		[Rr][Tt][Aa][Dd][Vv]) ;;
		[Nn][Oo][Rr][Tt][Aa][Dd][Vv]) ;;
		*)
			_args="$_args $_arg"
			;;
		esac
	done

	echo $_args
}

# autoif
#	Returns 0 if the interface should be automaticly 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`

	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`

	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
}

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

	case ${_af} in
	inet)
		${SYSCTL_N} net.inet > /dev/null 2>&1
		;;
	inet6)
		${SYSCTL_N} net.inet6 > /dev/null 2>&1
		;;
	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
		;;
	*)
		err 1 "afexists(): Unsupported address family: $_af"
		;;
	esac
}

# ipv6if if
#	Returns 0 if the interface should be configured for IPv6 and
#	1 otherwise.
ipv6if()
{
	if ! afexists inet6; then
		return 1
	fi

	# lo0 is always IPv6-enabled
	case $1 in
	lo0)
		return 0
		;;
	esac

	local _if _tmpargs i
	_if=$1

	case "$ipv6_network_interfaces" in
	''|[Nn][Oo][Nn][Ee])
		return 1
		;;
	$_if|"$_if "*|*" $_if"|*" $_if "*|[Aa][Uu][Tt][Oo])
		# True if $ifconfig_IF_ipv6 is defined.
		_tmpargs=`_ifconfig_getargs $_if ipv6`
		;;
	esac

	if [ -n "$_tmpargs" ]; then
		# Remove in FreeBSD 10.x
		# Explicit test is necessary here to avoid nonexistence error
		case "$ipv6_enable" in
		[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
			;;
		*)	return 0
			;;
		esac
	fi

	return 1
}

# ipv6_autoconfif if
#	Returns 0 if the interface should be configured for IPv6 with
#	Stateless Address Configuration, 1 otherwise.
ipv6_autoconfif()
{
	case $1 in
	lo0|\
	stf[0-9]*|\
	faith[0-9]*|\
	lp[0-9]*|\
	sl[0-9]*|\
	pflog[0-9]*|\
	pfsync[0-9]*)
		return 1
		;;
	esac

	local _if _tmpargs _arg
	_if=$1

	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
	if ! is_wired_interface $_if; then
		case $_if in
		wlan[0-9]*)	;;	# Allow test to continue
		*)	return 1
			;;
		esac
	fi

	_tmpargs=`_ifconfig_getargs $_if ipv6`
	case "$_tmpargs" in
	*inet6\ *|*[Nn][Oo][Rr][Tt][Aa][Dd][Vv]*|*-accept_rtadv*)
		return 1
		;;
	*[Rr][Tt][Aa][Dd][Vv]*|*accept_rtadv*)
		return 0
		;;
	esac

	return 1
}

# ifexists if
#	Returns 0 if the interface exists and 1 otherwise.
ifexists()
{
	[ -z "$1" ] && return 1
	ifconfig -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

	ifalias_up ${_if} inet && _ret=0
	ipv4_addrs_common ${_if} 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_up ${_if} inet6 && _ret=0
	ipv6_prefix_hostid_addr_up ${_if} && _ret=0
	ipv6_accept_rtadv_up ${_if} && _ret=0

	# wait for DAD
	sleep `${SYSCTL_N} net.inet6.ip6.dad_count`
	sleep 1

	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

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

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

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

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

	ifalias_down ${_if} inet && _ret=0
	ipv4_addrs_common ${_if} -alias && _ret=0

	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
	ifalias_down ${_if} inet6 && _ret=0

	inetList="`ifconfig ${_if} | grep 'inet6 ' | tr "\n" "$_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 ${_if} ${_inet6} -alias
		IFS="$_ifs"
		_ret=0
	done
	IFS="$oldifs"

	return $_ret
}

# ipv4_addrs_common if action
#	Evaluate the ifconfig_if_ipv4 arguments for interface $if and
#	use $action to add or remove IPv4 addresses from $if.
ipv4_addrs_common()
{
	local _ret _if _action _cidr _cidr_addr
	local _ipaddr _netmask _range _ipnet _iplow _iphigh _ipcount 
	_ret=1
	_if=$1
	_action=$2
    
	# get ipv4-addresses
	cidr_addr=`get_if_var $_if ipv4_addrs_IF`
    
	for _cidr in ${cidr_addr}; do
		_ipaddr=${_cidr%%/*}
		_netmask="/"${_cidr##*/}
		_range=${_ipaddr##*.}
		_ipnet=${_ipaddr%.*}
		_iplow=${_range%-*}
		_iphigh=${_range#*-}

		# clear netmask when removing aliases
		if [ "${_action}" = "-alias" ]; then
			_netmask=""
		fi
        
		_ipcount=${_iplow}
		while [ "${_ipcount}" -le "${_iphigh}" ]; do
			eval "ifconfig ${_if} ${_action} ${_ipnet}.${_ipcount}${_netmask}"
			_ipcount=$((${_ipcount}+1))
			_ret=0

			# only the first ipaddr in a subnet need the real netmask
			if [ "${_action}" != "-alias" ]; then
				_netmask="/32"
			fi
		done
	done

	return $_ret
}

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

	case "$2" in
	inet)
		_ret=`ifalias_ipv4_up "$1"`
		;;
	inet6)
		_ret=`ifalias_ipv6_up "$1"`
		;;
	esac

	return $_ret
}

# ifalias_ipv4_up if
#	Helper function for ifalias_up().  Handles IPv4.
#
ifalias_ipv4_up()
{
	local _ret alias ifconfig_args
	_ret=1

	# ifconfig_IF_aliasN which starts with "inet"
	alias=0
	while : ; do
		ifconfig_args=`get_if_var $1 ifconfig_IF_alias${alias}`
		case "${ifconfig_args}" in
		inet\ *)
			ifconfig $1 ${ifconfig_args} alias && _ret=0
			;;
		"")
			break
			;;
		esac
		alias=$((${alias} + 1))
	done

	return $_ret
}

# ifalias_ipv6_up if
#	Helper function for ifalias_up().  Handles IPv6.
#
ifalias_ipv6_up()
{
	local _ret alias ifconfig_args
	_ret=1

	# ifconfig_IF_aliasN which starts with "inet6"
	alias=0
	while : ; do
		ifconfig_args=`get_if_var $1 ifconfig_IF_alias${alias}`
		case "${ifconfig_args}" in
		inet6\ *)
			ifconfig $1 ${ifconfig_args} alias && _ret=0
			;;
		"")
			break
			;;
		esac
		alias=$((${alias} + 1))
	done

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

	return $_ret
}

# ifalias_down if af
#	Remove aliases for network interface $if.
#	It returns 0 if at least one alias was removed or
#	1 if there were none.
#
ifalias_down()
{
	local _ret
	_ret=1

	case "$2" in
	inet)
		_ret=`ifalias_ipv4_down "$1"`
		;;
	inet6)
		_ret=`ifalias_ipv6_down "$1"`
		;;
	esac

	return $_ret
}

# ifalias_ipv4_down if
#	Helper function for ifalias_down().  Handles IPv4.
#
ifalias_ipv4_down()
{
	local _ret alias ifconfig_args
	_ret=1

	# ifconfig_IF_aliasN which starts with "inet"
	alias=0
	while : ; do
		ifconfig_args=`get_if_var $1 ifconfig_IF_alias${alias}`
		case "${ifconfig_args}" in
		inet\ *)
			ifconfig $1 ${ifconfig_args} -alias && _ret=0
			;;
		"")
			break
			;;
		esac
		alias=$((${alias} + 1))
	done

	return $_ret
}

# ifalias_ipv6_down if
#	Helper function for ifalias_down().  Handles IPv6.
#
ifalias_ipv6_down()
{
	local _ret alias ifconfig_args
	_ret=1

	# ifconfig_IF_aliasN which starts with "inet6"
	alias=0
	while : ; do
		ifconfig_args=`get_if_var $1 ifconfig_IF_alias${alias}`
		case "${ifconfig_args}" in
		inet6\ *)
			ifconfig $1 ${ifconfig_args} -alias && _ret=0
			;;
		"")
			break
			;;
		esac
		alias=$((${alias} + 1))
	done

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

	return $_ret
}

# ipv6_prefix_hostid_addr_up if
#	add IPv6 prefix + hostid addr to the interface $if
ipv6_prefix_hostid_addr_up()
{
	local _if prefix laddr hostid j address
	_if=$1
	prefix=`get_if_var ${_if} ipv6_prefix_IF`

	if [ -n "${prefix}" ]; then
		laddr=`network6_getladdr ${_if}`
		hostid=${laddr#fe80::}
		hostid=${hostid%\%*}

		for j in ${prefix}; do
			address=$j\:${hostid}
			ifconfig ${_if} inet6 ${address} prefixlen 64 alias

			# if I am a router, add subnet router
			# anycast address (RFC 2373).
			if checkyesno ipv6_gateway_enable; then
				ifconfig ${_if} inet6 $j:: prefixlen 64 \
					alias 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 $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 $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
	_prefix=
	_list=

	# create_args_IF
	for ifn in ${cloned_interfaces}; do
		ifconfig ${ifn} create `get_if_var ${ifn} create_args_IF`
		if [ $? -eq 0 ]; then
			_list="${_list}${_prefix}${ifn}"
			[ -z "$_prefix" ] && _prefix=' '
		fi
	done
	debug "Cloned: ${_list}"
}

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

	for ifn in ${cloned_interfaces}; do
		ifconfig ${ifn} destroy
		if [ $? -eq 0 ]; then
			_list="${_list}${_prefix}${ifn}"
			[ -z "$_prefix" ] && _prefix=' '
		fi
	done
	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 $child create ${create_args} && cfg=0
			if [ -n "${debug_flags}" ]; then
				wlandebug -i $child ${debug_flags}
			fi
		else
			i=`ifconfig wlan create ${create_args}`
			if [ -n "${debug_flags}" ]; then
				wlandebug -i $i ${debug_flags}
			fi
			ifconfig $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 $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 $child create ${create_args} && cfg=0
			else
				i=`ifconfig vlan create ${create_args}`
				ifconfig $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
		if autoif $child; then
			ifn_stop $child
		fi
		ifconfig $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
		if autoif $child; then
			ifn_stop $child
		fi
		ifconfig $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
}

# gif_up
#	Create gif(4) tunnel interfaces.
gif_up()
{
	local i peers

	for i in ${gif_interfaces}; do
		peers=`get_if_var $i gifconfig_IF`
		case ${peers} in
		'')
			continue
			;;
		*)
			if expr $i : 'gif[0-9][0-9]*$' >/dev/null 2>&1; then
				ifconfig $i create >/dev/null 2>&1
			else
				gif=`ifconfig gif create`
				ifconfig $gif name $i
			fi
			ifconfig $i tunnel ${peers}
			ifconfig $i up
			;;
		esac
	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 ${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 ${_if} | grep 'ipx ' | tr "\n" "$_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 ${_if} ${_ipx} delete
		IFS="$_ifs"
		_ret=0
	done
	IFS="$oldifs"

	return $_ret
}

# ifnet_rename
#	Rename all requested interfaces.
#
ifnet_rename()
{
	local _if _ifname

	# ifconfig_IF_name
	for _if in `ifconfig -l`; do
		_ifname=`get_if_var $_if ifconfig_IF_name`
		if [ ! -z "$_ifname" ]; then
			ifconfig $_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 -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()
{
	if [ $1 -lt 10 ]; then
		echo $1
	else
		case $1 in
		10)	echo a ;;
		11)	echo b ;;
		12)	echo c ;;
		13)	echo d ;;
		14)	echo e ;;
		15)	echo f ;;
		esac
	fi
}

# hexprint arg
#	Echo decimal number $arg (multiple digits) in hexadecimal format.
hexprint()
{
	local val str dig
	val=$1
	str=''
	dig=`hexdigit $((${val} & 15))`
	str=${dig}${str}
	val=$((${val} >> 4))

	while [ ${val} -gt 0 ]; do
		dig=`hexdigit $((${val} & 15))`
		str=${dig}${str}
		val=$((${val} >> 4))
	done

	echo ${str}
}

is_wired_interface()
{
	local media

	case `ifconfig $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 proto addr rest
	ifconfig $1 2>/dev/null | while read proto addr rest; do
		case ${proto} in
		inet6)
			case ${addr} in
			fe80::*)
				if [ -z "$2" ]; then
					echo ${addr}
					return
				fi
				case ${rest} in
				*tentative*)
					continue
					;;
				*)
					echo ${addr}
					return
				esac
			esac
		esac
	done
}