hostname.subr revision 244797
1if [ ! "$_NETWORKING_HOSTNAME_SUBR" ]; then _NETWORKING_HOSTNAME_SUBR=1
2#
3# Copyright (c) 2006-2012 Devin Teske
4# All Rights Reserved.
5#
6# Redistribution and use in source and binary forms, with or without
7# modification, are permitted provided that the following conditions
8# are met:
9# 1. Redistributions of source code must retain the above copyright
10#    notice, this list of conditions and the following disclaimer.
11# 2. Redistributions in binary form must reproduce the above copyright
12#    notice, this list of conditions and the following disclaimer in the
13#    documentation and/or other materials provided with the distribution.
14#
15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE
17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20# DAMAGES (INLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25# SUCH DAMAGE.
26#
27# $FreeBSD: head/usr.sbin/bsdconfig/networking/share/hostname.subr 244797 2012-12-28 23:27:17Z dteske $
28#
29############################################################ INCLUDES
30
31BSDCFG_SHARE="/usr/share/bsdconfig"
32. $BSDCFG_SHARE/common.subr || exit 1
33f_dprintf "%s: loading includes..." networking/hostname.subr
34f_include $BSDCFG_SHARE/sysrc.subr
35f_include $BSDCFG_SHARE/dialog.subr
36f_include $BSDCFG_SHARE/networking/common.subr
37f_include $BSDCFG_SHARE/networking/resolv.subr
38
39BSDCFG_LIBE="/usr/libexec/bsdconfig" APP_DIR="120.networking"
40f_include_lang $BSDCFG_LIBE/$APP_DIR/include/messages.subr
41
42############################################################ FUNCTIONS
43
44# f_validate_hostname $hostname
45#
46# Returns zero if the given argument (a fully-qualified hostname) is compliant
47# with standards set-forth in RFC's 952 and 1123 of the Network Working Group:
48#
49# RFC 952 - DoD Internet host table specification
50# http://tools.ietf.org/html/rfc952
51#
52# RFC 1123 - Requirements for Internet Hosts - Application and Support
53# http://tools.ietf.org/html/rfc1123
54#
55# See http://en.wikipedia.org/wiki/Hostname for a brief overview.
56#
57# The return status for invalid hostnames is one of:
58# 	255	Entire hostname exceeds the maximum length of 255 characters.
59# 	 63	One or more individual labels within the hostname (separated by
60# 	   	dots) exceeds the maximum of 63 characters.
61# 	  1	One or more individual labels within the hostname contains one
62# 	   	or more invalid characters.
63# 	  2	One or more individual labels within the hostname starts or
64# 	   	ends with a hyphen (hyphens are allowed, but a label cannot
65# 	   	begin or end with a hyphen).
66# 	  3	One or more individual labels within the hostname are null.
67#
68# If the hostname is determined to be invalid, the appropriate error will be
69# displayed using the f_show_msg function.
70#
71f_validate_hostname()
72{
73	local fqhn="$1"
74
75	( # Operate within a sub-shell to protect the parent environment
76
77		# Return error if the hostname exceeds 255 characters
78		[ ${#fqhn} -gt 255 ] && exit 255
79
80		IFS="." # Split on `dot'
81		for label in $fqhn; do
82
83			# Return error if the label exceeds 63 characters
84			[ ${#label} -gt 63 ] && exit 63
85
86			# Return error if the label is null
87			[ "$label" ] || exit 3
88
89			# Return error if label begins/ends with dash
90			case "$label" in
91			-*|*-) exit 2
92			esac
93
94			# Return error if the label contains any invalid chars
95			echo "$label" | grep -q '^[[:alnum:]-]*$' || exit 1
96
97		done
98	)
99}
100
101# f_dialog_hnerror $error $hostname
102#
103# Display a msgbox with the appropriate error message for an error returned by
104# the f_validate_hostname function.
105#
106f_dialog_hnerror()
107{
108	local error="$1" fqhn="$2"
109
110	[ ${error:-0} -ne 0 ] || return $SUCCESS
111
112	case "$error" in
113	1) f_show_msg "$msg_hostname_label_contains_invalid_chars" "$fqhn";;
114	2) f_show_msg "$msg_hostname_label_starts_or_ends_with_hyphen" "$fqhn";;
115	3) f_show_msg "$msg_hostname_label_is_null" "$fqhn";;
116	63) f_show_msg "$msg_hostname_label_exceeds_max_length" "$fqhn";;
117	255) f_show_msg "$msg_hostname_exceeds_max_length" "$fqhn";;
118	esac
119}
120
121# f_dialog_validate_hostname $hostname
122#
123# Returns zero if the given argument (a fully-qualified hostname) is compliant
124# with standards set-forth in RFC's 952 and 1123 of the Network Working Group:
125#
126# RFC 952 - DoD Internet host table specification
127# http://tools.ietf.org/html/rfc952
128#
129# RFC 1123 - Requirements for Internet Hosts - Application and Support
130# http://tools.ietf.org/html/rfc1123
131#
132# If the hostname is determined to be invalid, the appropriate error will be
133# displayed using the f_dialog_hnerror function above.
134#
135f_dialog_validate_hostname()
136{
137	local fqhn="$1"
138
139	f_validate_hostname "$fqhn"
140	local retval=$?
141
142	# Produce an appropriate error message if necessary.
143	[ $retval -eq $SUCCESS ] || f_dialog_hnerror $retval "$fqhn"
144
145	return $retval
146}
147
148# f_dialog_input_hostname
149#
150# Edits the current hostname.
151#
152f_dialog_input_hostname()
153{
154	local hostname="$( f_sysrc_get 'hostname:-$(hostname)' )"
155	local hostname_orig="$hostname" # for change-tracking
156
157	local msg
158	if [ "$USE_XDIALOG" ]; then
159		msg="$xmsg_please_enter_fqhn"
160	else
161		msg="$msg_please_enter_fqhn"
162	fi
163
164	#
165	# Loop until the user provides taint-free input.
166	#
167	while :; do
168		hostname=$( f_dialog_input "$msg" "$hostname" \
169		                           "$hline_alnum_punc_tab_enter"
170		          ) || return
171		# Taint-check the user's input
172		f_dialog_validate_hostname "$hostname" && break
173	done
174
175	#
176	# Save hostname only if the user changed the hostname.
177	#
178	if [ "$hostname" != "$hostname_orig" ]; then
179		f_dialog_info "$msg_saving_hostname"
180		f_sysrc_set hostname "$hostname"
181	fi
182
183	#
184	# Update resolv.conf(5) search/domain directives
185	#
186	f_dialog_resolv_conf_update "$hostname"
187
188	#
189	# Only ask to apply setting if the current hostname is different than
190	# the stored configuration (in rc.conf(5)).
191	#
192	if [ "$( hostname )" != "$( f_sysrc_get hostname )" ]; then
193		[ ! "$USE_XDIALOG" ] && f_dialog_clear
194
195		#
196		# If connected via ssh(1) and performing X11-Forwarding, don't
197		# allow the hostname to be changed to prevent the fatal error
198		# "X11 connection rejected because of wrong authentication."
199		#
200		if [ "$USE_XDIALOG" -a "$SSH_CONNECTION" ]; then
201			f_show_msg "$msg_activate_hostname_x11warning" \
202			           "$( hostname )" "$hostname"
203		else
204			f_dialog_yesno "$(
205				printf "$msg_activate_hostname" \
206				       "$( hostname )" "$hostname" \
207			)" \
208			&& hostname "$hostname"
209		fi
210	fi
211
212	return $SUCCESS
213}
214
215############################################################ MAIN
216
217f_dprintf "%s: Successfully loaded." networking/hostname.subr
218
219fi # ! $_NETWORKING_HOSTNAME_SUBR
220