xref: /freebsd/usr.sbin/bsdconfig/networking/share/hostname.subr (revision 35a157a0eb81363303899064c3078f63cda511e1)

if [ ! "$_NETWORKING_HOSTNAME_SUBR" ]; then _NETWORKING_HOSTNAME_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.
#
# $FreeBSD$
#
############################################################ INCLUDES

BSDCFG_SHARE="/usr/share/bsdconfig"
. $BSDCFG_SHARE/common.subr || exit 1
f_include $BSDCFG_SHARE/sysrc.subr
f_include $BSDCFG_SHARE/dialog.subr
f_include $BSDCFG_SHARE/networking/common.subr
f_include $BSDCFG_SHARE/networking/resolv.subr

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

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

# f_validate_hostname $hostname
#
# Returns zero if the given argument (a fully-qualified hostname) is compliant
# with standards set-forth in RFC's 952 and 1123 of the Network Working Group:
#
# RFC 952 - DoD Internet host table specification
# http://tools.ietf.org/html/rfc952
#
# RFC 1123 - Requirements for Internet Hosts - Application and Support
# http://tools.ietf.org/html/rfc1123
#
# See http://en.wikipedia.org/wiki/Hostname for a brief overview.
#
# The return status for invalid hostnames is one of:
# 	255	Entire hostname exceeds the maximum length of 255 characters.
# 	 63	One or more individual labels within the hostname (separated by
# 	   	dots) exceeds the maximum of 63 characters.
# 	  1	One or more individual labels within the hostname contains one
# 	   	or more invalid characters.
# 	  2	One or more individual labels within the hostname starts or
# 	   	ends with a hyphen (hyphens are allowed, but a label cannot
# 	   	begin or end with a hyphen).
# 	  3	One or more individual labels within the hostname are null.
#
# If the hostname is determined to be invalid, the appropriate error will be
# displayed using the f_show_msg function.
#
f_validate_hostname()
{
	local fqhn="$1"

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

		# Return error if the hostname exceeds 255 characters
		[ ${#fqhn} -gt 255 ] && exit 255

		IFS="." # Split on `dot'
		for label in $fqhn; do

			# Return error if the label exceeds 63 characters
			[ ${#label} -gt 63 ] && exit 63

			# Return error if the label is null
			[ "$label" ] || exit 3

			# Return error if label begins/ends with dash
			case "$label" in
			-*|*-) exit 2
			esac

			# Return error if the label contains any invalid chars
			echo "$label" | grep -q '^[[:alnum:]-]*$' || exit 1

		done
	)
}

# f_dialog_hnerror $error $hostname
#
# Display a msgbox with the appropriate error message for an error returned by
# the f_validate_hostname function.
#
f_dialog_hnerror()
{
	local error="$1" fqhn="$2"

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

	case "$error" in
	1) f_show_msg "$msg_hostname_label_contains_invalid_chars" "$fqhn";;
	2) f_show_msg "$msg_hostname_label_starts_or_ends_with_hyphen" "$fqhn";;
	3) f_show_msg "$msg_hostname_label_is_null" "$fqhn";;
	63) f_show_msg "$msg_hostname_label_exceeds_max_length" "$fqhn";;
	255) f_show_msg "$msg_hostname_exceeds_max_length" "$fqhn";;
	esac
}

# f_dialog_validate_hostname $hostname
#
# Returns zero if the given argument (a fully-qualified hostname) is compliant
# with standards set-forth in RFC's 952 and 1123 of the Network Working Group:
#
# RFC 952 - DoD Internet host table specification
# http://tools.ietf.org/html/rfc952
#
# RFC 1123 - Requirements for Internet Hosts - Application and Support
# http://tools.ietf.org/html/rfc1123
#
# If the hostname is determined to be invalid, the appropriate error will be
# displayed using the f_dialog_hnerror function above.
#
f_dialog_validate_hostname()
{
	local fqhn="$1"

	f_validate_hostname "$fqhn"
	local retval=$?

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

	return $retval
}

# f_dialog_input_hostname
#
# Edits the current hostname.
#
f_dialog_input_hostname()
{
	local hostname="$( f_sysrc_get 'hostname:-$(hostname)' )"
	local hostname_orig="$hostname" # for change-tracking

	local msg
	if [ "$USE_XDIALOG" ]; then
		msg="$xmsg_please_enter_fqhn"
	else
		msg="$msg_please_enter_fqhn"
	fi

	#
	# Loop until the user provides taint-free input.
	#
	while :; do
		hostname=$( f_dialog_input "$msg" "$hostname" \
		                           "$hline_alnum_punc_tab_enter"
		          ) || return
		# Taint-check the user's input
		f_dialog_validate_hostname "$hostname" && break
	done

	#
	# Save hostname only if the user changed the hostname.
	#
	if [ "$hostname" != "$hostname_orig" ]; then
		f_dialog_info "$msg_saving_hostname"
		f_sysrc_set hostname "$hostname"
	fi

	#
	# Update resolv.conf(5) search/domain directives
	#
	f_dialog_resolv_conf_update "$hostname"

	#
	# Only ask to apply setting if the current hostname is different than
	# the stored configuration (in rc.conf(5)).
	#
	if [ "$( hostname )" != "$( f_sysrc_get hostname )" ]; then
		[ ! "$USE_XDIALOG" ] && dialog_clear

		#
		# If connected via ssh(1) and performing X11-Forwarding, don't
		# allow the hostname to be changed to prevent the fatal error
		# "X11 connection rejected because of wrong authentication."
		#
		if [ "$USE_XDIALOG" -a "$SSH_CONNECTION" ]; then
			f_show_msg "$msg_activate_hostname_x11warning" \
			           "$( hostname )" "$hostname"
		else
			f_dialog_yesno "$(
				printf "$msg_activate_hostname" \
				       "$( hostname )" "$hostname" \
			)" \
			&& hostname "$hostname"
		fi
	fi

	return $SUCCESS
}

fi # ! $_NETWORKING_HOSTNAME_SUBR