xref: /freebsd-10.1-release/usr.sbin/bsdconfig/networking/share/ipaddr.subr

if [ ! "$_NETWORKING_IPADDR_SUBR" ]; then _NETWORKING_IPADDR_SUBR=1
#
# Copyright (c) 2006-2012 Devin Teske
# 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 AUTHOR 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 AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INLUDING, 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: head/usr.sbin/bsdconfig/networking/share/ipaddr.subr 244675 2012-12-25 10:47:45Z dteske $
#
############################################################ INCLUDES

BSDCFG_SHARE="/usr/share/bsdconfig"
. $BSDCFG_SHARE/common.subr || exit 1
f_dprintf "%s: loading includes..." networking/ipaddr.subr
f_include $BSDCFG_SHARE/dialog.subr
f_include $BSDCFG_SHARE/strings.subr
f_include $BSDCFG_SHARE/networking/common.subr

BSDCFG_LIBE="/usr/libexec/bsdconfig" APP_DIR="120.networking"
f_include_lang $BSDCFG_LIBE/$APP_DIR/include/messages.subr

############################################################ FUNCTIONS

# f_ifconfig_inet $interface
#
# Returns the IPv4 address associated with $interface.
#
f_ifconfig_inet()
{
	local interface="$1"
	ifconfig "$interface" 2> /dev/null | awk \
	'
		BEGIN { found = 0 }
		( $1 == "inet" ) \
		{
			print $2
			found = 1
			exit
		}
		END { exit ! found }
	'
}

# f_validate_ipaddr $ipaddr
#
# Returns zero if the given argument (an IP address) is of the proper format.
#
# The return status for invalid IP address is one of:
# 	1	One or more individual octets within the IP address (separated
# 	 	by dots) contains one or more invalid characters.
# 	2	One or more individual octets within the IP address are null
# 	 	and/or missing.
# 	3	One or more individual octets within the IP address exceeds the
# 	 	maximum of 255 (or 2^8, being an octet comprised of 8 bits).
# 	4	The IP address has either too few or too many octets.
#
f_validate_ipaddr()
{
	local ip="$1"

	( # Operate within a sub-shell to protect the parent environment

		# Track number of octets for error checking
		noctets=0

		IFS="." # Split on `dot'
		for octet in $ip; do

			# Return error if the octet is null
			[ "$octet" ] || exit 2

			# Return error if not a whole integer
			f_isinteger "$octet" || exit 1

			# Return error if not a positive integer
			[ $octet -ge 0 ] || exit 1

			# Return error if the octet exceeds 255
			[ $octet -gt 255 ] && exit 3

			noctets=$(( $noctets + 1 ))

		done

		[ $noctets -eq 4 ] || exit 4
	)
}
# f_dialog_iperror $error $ipaddr
#
# Display a msgbox with the appropriate error message for an error returned by
# the f_validate_ipaddr function above.
#
f_dialog_iperror()
{
	local error="$1" ip="$2"

	[ ${error:-0} -ne 0 ] || return $SUCCESS

	case "$error" in
	1) f_show_msg "$msg_ipv4_addr_octet_contains_invalid_chars" "$ip";;
	2) f_show_msg "$msg_ipv4_addr_octet_is_null" "$ip";;
	3) f_show_msg "$msg_ipv4_addr_octet_exceeds_max_value" "$ip";;
	4) f_show_msg "$msg_ipv4_addr_octet_missing_or_extra" "$ip";;
	esac
}

# f_dialog_validate_ipaddr $ipaddr
#
# Returns zero if the given argument (an IP address) is of the proper format.
#
# If the IP address is determined to be invalid, the appropriate error will be
# displayed using the f_dialog_iperror function above.
#
f_dialog_validate_ipaddr()
{
	local ip="$1"

	f_validate_ipaddr "$ip"
	local retval=$?

	# Produce an appropriate error message if necessary.
	[ $retval -eq $SUCCESS ] || f_dialog_iperror $retval "$ip"

	return $retval
}

# f_validate_ipaddr6 $ipv6_addr
#
# Returns zero if the given argument (an IPv6 address) is of the proper format.
#
# The return status for invalid IP address is one of:
# 	1	One or more individual segments within the IP address
# 	 	(separated by colons) contains one or more invalid characters.
# 	 	Segments must contain only combinations of the characters 0-9,
# 	 	A-F, or a-f.
# 	2	Too many/incorrect null segments. A single null segment is
# 	 	allowed within the IP address (separated by colons) but not
# 	 	allowed at the beginning or end (unless a double-null segment;
# 	 	i.e., "::*" or "*::").
# 	3	One or more individual segments within the IP address
# 	 	(separated by colons) exceeds the length of 4 hex-digits.
# 	4	The IP address entered has either too few (less than 3), too
# 	 	many (more than 8), or not enough segments, separated by
# 	 	colons.
# 	5*	The IPv4 address at the end of the IPv6 address is invalid.
# 	*	When there is an error with the dotted-quad IPv4 address at the
# 	 	end of the IPv6 address, the return value of 5 is OR'd with a
# 	 	bit-shifted (<< 4) return of f_validate_ipaddr.
#
f_validate_ipaddr6()
{
	local ip="$1"

	( # Operate within a sub-shell to protect the parent environment

		IFS=":" # Split on `colon'
		set -- $ip:

		# Return error if too many or too few segments
		# Using 9 as max in case of leading or trailing null spanner
		[ $# -gt 9 -o $# -lt 3 ] && exit 4

		h="[0-9A-Fa-f]"
		nulls=0
		nsegments=$#
		contains_ipv4_segment=

		while [ $# -gt 0 ]; do

			segment="${1%:}"
			shift

			#
			# Return error if this segment makes one null too-many.
			# A single null segment is allowed anywhere in the
			# middle as well as double null segments are allowed at
			# the beginning or end (but not both).
			#
			if [ ! "$segment" ]; then
				nulls=$(( $nulls + 1 ))
				if [ $nulls -eq 3 ]; then
					# Only valid syntax for 3 nulls is `::'
					[ "$ip" = "::" ] || exit 2
				elif [ $nulls -eq 2 ]; then
					# Only valid if begins/ends with `::'
					case "$ip" in
					::*|*::) : fall thru ;;
					*) exit 2
					esac
				fi
				continue
			fi

			#
			# Return error if not a valid hexadecimal short
			#
			case "$segment" in
			$h|$h$h|$h$h$h|$h$h$h$h)
				: valid segment of 1-4 hexadecimal digits
				;;
			*[!0-9A-Fa-f]*)
				# Segment contains at least one invalid char

				# Return error immediately if not last segment
				[ $# -eq 0 ] || exit 1

				# Otherwise, check for legacy IPv4 notation
				case "$segment" in
				*[!0-9.]*)
					# Segment contains at least one invalid
					# character even for an IPv4 address
					exit 1
				esac

				# Return error if not enough segments
				if [ $nulls -eq 0 ]; then
					[ $nsegments -eq 7 ] || exit 4
				fi

				contains_ipv4_segment=1

				# Validate the IPv4 address
				f_validate_ipaddr "$segment" ||
					exit $(( 5 | $? << 4 ))
				;;
			*)
				# Segment characters are all valid but too many
				exit 3
			esac

		done

		if [ $nulls -eq 1 ]; then
			# Single null segment cannot be at beginning/end
			case "$ip" in
			:*|*:) exit 2
			esac
		fi

		#
		# A legacy IPv4 address can span the last two 16-bit segments,
		# reducing the amount of maximum allowable segments by-one.
		#
		maxsegments=8
		if [ "$contains_ipv4_segment" ]; then
			maxsegments=7
		fi

		case $nulls in
		# Return error if missing segments with no null spanner
		0) [ $nsegments -eq $maxsegments ] || exit 4 ;;
		# Return error if null spanner with too many segments
		1) [ $nsegments -le $maxsegments ] || exit 4 ;;
		# Return error if leading/trailing `::' with too many segments
		2) [ $nsegments -le $(( $maxsegments + 1 )) ] || exit 4 ;;
		esac

		exit $SUCCESS
	)
}

# f_dialog_ip6error $error $ipv6_addr
#
# Display a msgbox with the appropriate error message for an error returned by
# the f_validate_ipaddr6 function above.
#
f_dialog_ip6error()
{
	local error="$1" ip="$2"

	[ ${error:-0} -ne 0 ] || return $SUCCESS

	case "$error" in
	1) f_show_msg "$msg_ipv6_addr_segment_contains_invalid_chars" "$ip";;
	2) f_show_msg "$msg_ipv6_addr_too_many_null_segments" "$ip";;
	3) f_show_msg "$msg_ipv6_addr_segment_contains_too_many_chars" "$ip";;
	4) f_show_msg "$msg_ipv6_addr_too_few_or_extra_segments" "$ip";;
	*)
		if [ $(( $error & 0xF )) -eq 5 ]; then
			# IPv4 at the end of IPv6 address is invalid
			f_dialog_iperror $(( $error >> 4 )) "$ip"
		fi
	esac
}

# f_dialog_validate_ipaddr6 $ipv6_addr
#
# Returns zero if the given argument (an IPv6 address) is of the proper format.
#
# If the IP address is determined to be invalid, the appropriate error will be
# displayed using the f_dialog_ip6error function above.
#
f_dialog_validate_ipaddr6()
{
	local ip="$1"

	f_validate_ipaddr6 "$ip"
	local retval=$?

	# Produce an appropriate error message if necessary.
	[ $retval -eq $SUCCESS ] || f_dialog_ip6error $retval "$ip"

	return $retval
}

# f_dialog_input_ipaddr $interface $ipaddr
#
# Allows the user to edit a given IP address. If the user does not cancel or
# press ESC, the $ipaddr environment variable will hold the newly-configured
# value upon return.
#
# Optionally, the user can enter the format "IP_ADDRESS/NBITS" to set the
# netmask at the same time as the IP address. If such a format is entered by
# the user, the $netmask environment variable will hold the newly-configured
# netmask upon return.
#
f_dialog_input_ipaddr()
{
	local interface="$1" _ipaddr="$2" _input

	#
	# Return with-error when there are NFS-mounts currently active. If the
	# IP address is changed while NFS-exported directories are mounted, the
	# system may hang (if any NFS mounts are using that interface).
	#
	if f_nfs_mounted && ! f_jailed; then
		local setting="$( printf "$msg_current_ipaddr" \
		                         "$interface" "$_ipaddr" )"
		f_show_msg "$msg_nfs_mounts_may_cause_hang" "$setting"
		return $FAILURE
	fi

	local msg="$( printf "$msg_please_enter_new_ip_addr" "$interface" )"

	#
	# Loop until the user provides taint-free input.
	#
	local retval
	while :; do
		#
		# Return error status if:
		# - User has either pressed ESC or chosen Cancel/No
		# - User has not made any changes to the given value
		#
		_input=$( f_dialog_input "$msg" "$_ipaddr" \
		                         "$hline_num_punc_tab_enter"
		        ) || return
		[ "$_ipaddr" = "$_input" ] && return $FAILURE

		# Return success if NULL value was entered
		[ "$_input" ] || return $SUCCESS

		# Take only the first "word" of the user's input
		_ipaddr="$_input"
		_ipaddr="${_ipaddr%%[$IFS]*}"

		# Taint-check the user's input
		f_dialog_validate_ipaddr "${_ipaddr%%/*}" && break
	done

	#
	# Support the syntax: IP_ADDRESS/NBITS
	#
	local _netmask=""
	case "$_ipaddr" in
	*/*)
		local nbits="${_ipaddr#*/}" n=0
		_ipaddr="${_ipaddr%%/*}"

		#
		# Taint-check $nbits to be (a) a positive whole-integer,
		# and (b) to be less than or equal to 32. Otherwise, set
		# $n so that the below loop never executes.
		#
		( f_isinteger "$nbits" && [ $nbits -ge 0 -a $nbits -le 32 ] ) \
			|| n=4

		while [ $n -lt 4 ]; do
			_netmask="$_netmask${_netmask:+.}$((
				(65280 >> ($nbits - 8 * $n) & 255)
				* ((8*$n) < $nbits & $nbits <= (8*($n+1)))
				+ 255 * ($nbits > (8*($n+1)))
			))"
			n=$(( $n + 1 ))
		done
		;;
	esac

	ipaddr="$_ipaddr"
	[ "$_netmask" ] && netmask="$_netmask"

	return $SUCCESS
}

############################################################ MAIN

f_dprintf "%s: Successfully loaded." networking/ipaddr.subr

fi # ! $_NETWORKING_IPADDR_SUBR