dhclient-script revision 148420 
1#!/bin/sh
2#
3# $OpenBSD: dhclient-script,v 1.6 2004/05/06 18:22:41 claudio Exp $
4# $FreeBSD: head/sbin/dhclient/dhclient-script 148420 2005-07-26 18:27:37Z brooks $
5#
6# Copyright (c) 2003 Kenneth R Westerback <krw@openbsd.org>
7#
8# Permission to use, copy, modify, and distribute this software for any
9# purpose with or without fee is hereby granted, provided that the above
10# copyright notice and this permission notice appear in all copies.
11#
12# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19#
20#
21
22NETSTAT=/usr/bin/netstat
23GREP=/usr/bin/grep
24AWK=/usr/bin/awk
25HOSTNAME=/bin/hostname
26
27LOCALHOST=127.0.0.1
28
29if [ -x /usr/bin/logger ]; then
30	LOGGER="/usr/bin/logger -s -p user.notice -t dhclient"
31else
32	LOGGER=echo
33fi
34
35#
36# Helper functions that implement common actions.
37#
38
39check_hostname() {
40	current_hostname=`$HOSTNAME`
41	if [ -z "$current_hostname" ]; then
42		$LOGGER "New Hostname ($interface): $new_host_name"
43		$HOSTNAME $new_host_name
44	elif [ "$current_hostname" = "$old_host_name" -a \
45	       "$new_host_name" != "$old_host_name" ]; then
46		$LOGGER "New Hostname ($interface): $new_host_name"
47		$HOSTNAME $new_host_name
48	fi
49}
50
51arp_flush() {
52	arp -an -i $interface | \
53		sed -n -e 's/^.*(\(.*\)) at .*$/arp -d \1/p' | \
54		sh >/dev/null 2>&1
55}
56
57delete_old_address() {
58	ifconfig $interface inet -alias $old_ip_address $medium
59}
60
61add_new_address() {
62	ifconfig $interface \
63		inet $new_ip_address \
64		netmask $new_subnet_mask \
65		broadcast $new_broadcast_address \
66		$medium
67
68	$LOGGER "New IP Address ($interface): $new_ip_address"
69	$LOGGER "New Subnet Mask ($interface): $new_subnet_mask"
70	$LOGGER "New Broadcast Address ($interface): $new_broadcast_address"
71	$LOGGER "New Routers ($interface): $new_routers"
72}
73
74delete_old_alias() {
75	if [ -n "$alias_ip_address" ]; then
76		ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
77		route delete $alias_ip_address $LOCALHOST > /dev/null 2>&1
78	fi
79}
80
81add_new_alias() {
82	if [ -n "$alias_ip_address" ]; then
83		ifconfig $interface inet alias $alias_ip_address netmask \
84		    $alias_subnet_mask
85		route add $alias_ip_address $LOCALHOST
86	fi
87}
88
89delete_old_routes() {
90	route delete "$old_ip_address" $LOCALHOST >/dev/null 2>&1
91	for router in $old_routers; do
92		if [ $if_defaultroute = x -o $if_defaultroute = $interface ]; then
93			route delete default $route >/dev/null 2>&1
94		fi
95	done
96
97	if [ -n "$old_static_routes" ]; then
98		set $old_static_routes
99		while [ $# -gt 1 ]; do
100			route delete "$1" "$2"
101			shift; shift
102		done
103	fi
104
105	arp_flush
106}
107
108add_new_routes() {
109	route add $new_ip_address $LOCALHOST >/dev/null 2>&1
110	for router in $new_routers; do
111		if [ "$new_ip_address" = "$router" ]; then
112			route add default -iface $router >/dev/null 2>&1
113		else
114			route add default $router >/dev/null 2>&1
115		fi
116		# 2nd and subsequent default routers error out, so explicitly
117		# stop processing the list after the first one.
118		break
119	done
120
121	if [ -n "$new_static_routes" ]; then
122		$LOGGER "New Static Routes ($interface): $new_static_routes"
123		set $new_static_routes
124		while [ $# -gt 1 ]; do
125			route add $1 $2
126			shift; shift
127		done
128	fi
129}
130
131add_new_resolv_conf() {
132	# XXX Old code did not create/update resolv.conf unless both
133	# $new_domain_name and $new_domain_name_servers were provided.  PR
134	# #3135 reported some ISP's only provide $new_domain_name_servers and
135	# thus broke the script. This code creates the resolv.conf if either
136	# are provided.
137
138	rm -f /etc/resolv.conf.std
139
140	if [ -n "$new_domain_name" ]; then
141		echo "search $new_domain_name" >>/etc/resolv.conf.std
142	fi
143
144	if [ -n "$new_domain_name_servers" ]; then
145		for nameserver in $new_domain_name_servers; do
146			echo "nameserver $nameserver" >>/etc/resolv.conf.std
147		done
148	fi
149
150	if [ -f /etc/resolv.conf.std ]; then
151		if [ -f /etc/resolv.conf.tail ]; then
152			cat /etc/resolv.conf.tail >>/etc/resolv.conf.std
153		fi
154
155		# In case (e.g. during OpenBSD installs) /etc/resolv.conf
156		# is a symbolic link, take care to preserve the link and write
157		# the new data in the correct location.
158
159		if [ -f /etc/resolv.conf ]; then
160			cat /etc/resolv.conf > /etc/resolv.conf.save
161		fi
162		cat /etc/resolv.conf.std > /etc/resolv.conf
163		rm -f /etc/resolv.conf.std
164
165		# Try to ensure correct ownership and permissions.
166		chown -RL root:wheel /etc/resolv.conf
167		chmod -RL 644 /etc/resolv.conf
168
169		return 0
170	fi
171
172	return 1
173}
174
175# Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
176exit_with_hooks() {
177	exit_status=$1
178	if [ -f /etc/dhclient-exit-hooks ]; then
179		. /etc/dhclient-exit-hooks
180	fi
181	# probably should do something with exit status of the local script
182	exit $exit_status
183}
184
185#
186# Start of active code.
187#
188
189# Invoke the local dhcp client enter hooks, if they exist.
190if [ -f /etc/dhclient-enter-hooks ]; then
191	exit_status=0
192	. /etc/dhclient-enter-hooks
193	# allow the local script to abort processing of this state
194	# local script must set exit_status variable to nonzero.
195	if [ $exit_status -ne 0 ]; then
196		exit $exit_status
197	fi
198fi
199
200if [ -x $NETSTAT ]; then
201	if_defaultroute=`$NETSTAT -rn | $GREP "^default" | $AWK '{print $6}'`
202else
203	if_defaultroute="x"
204fi
205
206case $reason in
207MEDIUM)
208	ifconfig $interface $medium
209	ifconfig $interface inet -alias 0.0.0.0 $medium >/dev/null 2>&1
210	sleep 1
211	;;
212
213PREINIT)
214	delete_old_alias
215	ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 broadcast 255.255.255.255 up
216	;;
217
218ARPCHECK|ARPSEND)
219	;;
220
221BOUND|RENEW|REBIND|REBOOT)
222	check_hostname
223	if [ -n "$old_ip_address" ]; then
224		if [ "$old_ip_address" != "$alias_ip_address" ]; then
225			delete_old_alias
226		fi
227		if [ "$old_ip_address" != "$new_ip_address" ]; then
228			delete_old_address
229			delete_old_routes
230		fi
231	fi
232	if [ "$reason" = BOUND ] || \
233	   [ "$reason" = REBOOT ] || \
234	   [ -z "$old_ip_address" ] || \
235	   [ "$old_ip_address" != "$new_ip_address" ]; then
236		add_new_address
237		add_new_routes
238	fi
239	if [ "$new_ip_address" != "$alias_ip_address" ]; then
240		add_new_alias
241	fi
242	add_new_resolv_conf
243	;;
244
245EXPIRE|FAIL)
246	delete_old_alias
247	if [ -n "$old_ip_address" ]; then
248		delete_old_address
249		delete_old_routes
250	fi
251	# XXX Why add alias we just deleted above?
252	add_new_alias
253	if [ -f /etc/resolv.conf.save ]; then
254		cat /etc/resolv.conf.save > /etc/resolv.conf
255	fi
256	;;
257
258TIMEOUT)
259	delete_old_alias
260	add_new_address
261	sleep 1
262	if [ -n "$new_routers" ]; then
263		$LOGGER "New Routers ($interface): $new_routers"
264		set "$new_routers"
265		if ping -q -c 1 -w 1 "$1"; then
266			if [ "$new_ip_address" != "$alias_ip_address" ]; then
267				add_new_alias
268			fi
269			add_new_routes
270			if add_new_resolv_conf; then
271				exit_with_hooks 0
272			fi
273		fi
274	fi
275	ifconfig $interface inet -alias $new_ip_address $medium
276	delete_old_routes
277	exit_with_hooks 1
278	;;
279esac
280
281exit_with_hooks 0
282