dhclient-script revision 179689
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 179689 2008-06-09 20:03:35Z 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 22ARP=/usr/sbin/arp 23HOSTNAME=/bin/hostname 24IFCONFIG='/sbin/ifconfig -n' 25 26LOCALHOST=127.0.0.1 27 28if [ -x /usr/bin/logger ]; then 29 LOGGER="/usr/bin/logger -s -p user.notice -t dhclient" 30else 31 LOGGER=echo 32fi 33 34# 35# Helper functions that implement common actions. 36# 37 38check_hostname() { 39 current_hostname=`$HOSTNAME` 40 if [ -z "$current_hostname" ]; then 41 $LOGGER "New Hostname ($interface): $new_host_name" 42 $HOSTNAME $new_host_name 43 elif [ "$current_hostname" = "$old_host_name" -a \ 44 "$new_host_name" != "$old_host_name" ]; then 45 $LOGGER "New Hostname ($interface): $new_host_name" 46 $HOSTNAME $new_host_name 47 fi 48} 49 50arp_flush() { 51 arp -an -i $interface | \ 52 sed -n -e 's/^.*(\(.*\)) at .*$/arp -d \1/p' | \ 53 sh >/dev/null 2>&1 54} 55 56delete_old_address() { 57 eval "$IFCONFIG $interface inet -alias $old_ip_address $medium" 58} 59 60add_new_address() { 61 eval "$IFCONFIG $interface \ 62 inet $new_ip_address \ 63 netmask $new_subnet_mask \ 64 broadcast $new_broadcast_address \ 65 $medium" 66 67 $LOGGER "New IP Address ($interface): $new_ip_address" 68 $LOGGER "New Subnet Mask ($interface): $new_subnet_mask" 69 $LOGGER "New Broadcast Address ($interface): $new_broadcast_address" 70 $LOGGER "New Routers ($interface): $new_routers" 71} 72 73delete_old_alias() { 74 if [ -n "$alias_ip_address" ]; then 75 $IFCONFIG $interface inet -alias $alias_ip_address > /dev/null 2>&1 76 #route delete $alias_ip_address $LOCALHOST > /dev/null 2>&1 77 fi 78} 79 80add_new_alias() { 81 if [ -n "$alias_ip_address" ]; then 82 $IFCONFIG $interface inet alias $alias_ip_address netmask \ 83 $alias_subnet_mask 84 #route add $alias_ip_address $LOCALHOST 85 fi 86} 87 88fill_classless_routes() { 89 set $1 90 while [ $# -ge 5 ]; do 91 if [ $1 -eq 0 ]; then 92 route="default" 93 elif [ $1 -le 8 ]; then 94 route="$2.0.0.0/$1" 95 shift 96 elif [ $1 -le 16 ]; then 97 route="$2.$3.0.0/$1" 98 shift; shift 99 elif [ $1 -le 24 ]; then 100 route="$2.$3.$4.0/$1" 101 shift; shift; shift 102 else 103 route="$2.$3.$4.$5/$1" 104 shift; shift; shift; shift 105 fi 106 shift 107 router="$1.$2.$3.$4" 108 classless_routes="$classless_routes $route $router" 109 shift; shift; shift; shift 110 done 111} 112 113delete_old_routes() { 114 #route delete "$old_ip_address" $LOCALHOST >/dev/null 2>&1 115 if [ -n "$old_classless_routes" ]; then 116 fill_classless_routes "$old_classless_routes" 117 set $classless_routes 118 while [ $# -gt 1 ]; do 119 route delete "$1" "$2" 120 shift; shift 121 done 122 return 0; 123 fi 124 125 # If we supported multiple default routes, we'd be removing each 126 # one here. We don't so just delete the default route if it's 127 # through our interface. 128 if is_default_interface; then 129 route delete default >/dev/null 2>&1 130 fi 131 132 if [ -n "$old_static_routes" ]; then 133 set $old_static_routes 134 while [ $# -gt 1 ]; do 135 route delete "$1" "$2" 136 shift; shift 137 done 138 fi 139 140 arp_flush 141} 142 143add_new_routes() { 144 #route add $new_ip_address $LOCALHOST >/dev/null 2>&1 145 146 # RFC 3442: If the DHCP server returns both a Classless Static 147 # Routes option and a Router option, the DHCP client MUST ignore 148 # the Router option. 149 # 150 # DHCP clients that support this option (Classless Static Routes) 151 # MUST NOT install the routes specified in the Static Routes 152 # option (option code 33) if both a Static Routes option and the 153 # Classless Static Routes option are provided. 154 155 if [ -n "$new_classless_routes" ]; then 156 fill_classless_routes "$new_classless_routes" 157 $LOGGER "New Classless Static Routes ($interface): $classless_routes" 158 set $classless_routes 159 while [ $# -gt 1 ]; do 160 if [ "0.0.0.0" = "$2" ]; then 161 route add "$1" -iface "$interface" 162 else 163 route add "$1" "$2" 164 fi 165 shift; shift 166 done 167 return 168 fi 169 170 for router in $new_routers; do 171 if is_default_interface; then 172 173 if [ "$new_ip_address" = "$router" ]; then 174 route add default -iface $router >/dev/null 2>&1 175 else 176 route add default $router >/dev/null 2>&1 177 fi 178 fi 179 # 2nd and subsequent default routers error out, so explicitly 180 # stop processing the list after the first one. 181 break 182 done 183 184 if [ -n "$new_static_routes" ]; then 185 $LOGGER "New Static Routes ($interface): $new_static_routes" 186 set $new_static_routes 187 while [ $# -gt 1 ]; do 188 route add $1 $2 189 shift; shift 190 done 191 fi 192} 193 194add_new_resolv_conf() { 195 # XXX Old code did not create/update resolv.conf unless both 196 # $new_domain_name and $new_domain_name_servers were provided. PR 197 # #3135 reported some ISP's only provide $new_domain_name_servers and 198 # thus broke the script. This code creates the resolv.conf if either 199 # are provided. 200 201 local tmpres=/var/run/resolv.conf.${interface} 202 rm -f $tmpres 203 204 if [ -n "$new_domain_name" ]; then 205 echo "search $new_domain_name" >>$tmpres 206 fi 207 208 if [ -n "$new_domain_name_servers" ]; then 209 for nameserver in $new_domain_name_servers; do 210 echo "nameserver $nameserver" >>$tmpres 211 done 212 fi 213 214 if [ -f $tmpres ]; then 215 if [ -f /etc/resolv.conf.tail ]; then 216 cat /etc/resolv.conf.tail >>$tmpres 217 fi 218 219 # When resolv.conf is not changed actually, we don't 220 # need to update it. 221 # If /usr is not mounted yet, we cannot use cmp, then 222 # the following test fails. In such case, we simply 223 # ignore an error and do update resolv.conf. 224 if cmp -s $tmpres /etc/resolv.conf; then 225 rm -f $tmpres 226 return 0 227 fi 2>/dev/null 228 229 # In case (e.g. during OpenBSD installs) /etc/resolv.conf 230 # is a symbolic link, take care to preserve the link and write 231 # the new data in the correct location. 232 233 if [ -f /etc/resolv.conf ]; then 234 cat /etc/resolv.conf > /etc/resolv.conf.save 235 fi 236 cat $tmpres > /etc/resolv.conf 237 rm -f $tmpres 238 239 # Try to ensure correct ownership and permissions. 240 chown -RL root:wheel /etc/resolv.conf 241 chmod -RL 644 /etc/resolv.conf 242 243 return 0 244 fi 245 246 return 1 247} 248 249# Must be used on exit. Invokes the local dhcp client exit hooks, if any. 250exit_with_hooks() { 251 exit_status=$1 252 if [ -f /etc/dhclient-exit-hooks ]; then 253 . /etc/dhclient-exit-hooks 254 fi 255 # probably should do something with exit status of the local script 256 exit $exit_status 257} 258 259# Get the interface with the current ipv4 default route on it using only 260# commands that are available prior to /usr being mounted. 261is_default_interface() 262{ 263 routeget="`route -n get -inet default`" 264 oldifs="$IFS" 265 IFS=" 266" 267 defif= 268 for line in $routeget ; do 269 case $line in 270 *interface:*) 271 defif=${line##*: } 272 ;; 273 esac 274 done 275 IFS=${oldifs} 276 277 if [ -z "$defif" -o "$defif" = "$interface" ]; then 278 return 0 279 else 280 return 1 281 fi 282} 283 284# 285# Start of active code. 286# 287 288# Invoke the local dhcp client enter hooks, if they exist. 289if [ -f /etc/dhclient-enter-hooks ]; then 290 exit_status=0 291 . /etc/dhclient-enter-hooks 292 # allow the local script to abort processing of this state 293 # local script must set exit_status variable to nonzero. 294 if [ $exit_status -ne 0 ]; then 295 exit $exit_status 296 fi 297fi 298 299case $reason in 300MEDIUM) 301 eval "$IFCONFIG $interface $medium" 302 eval "$IFCONFIG $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1 303 sleep 1 304 ;; 305 306PREINIT) 307 delete_old_alias 308 $IFCONFIG $interface inet alias 0.0.0.0 netmask 0.0.0.0 broadcast 255.255.255.255 up 309 ;; 310 311ARPCHECK|ARPSEND) 312 ;; 313 314BOUND|RENEW|REBIND|REBOOT) 315 check_hostname 316 if [ -n "$old_ip_address" ]; then 317 if [ "$old_ip_address" != "$alias_ip_address" ]; then 318 delete_old_alias 319 fi 320 if [ "$old_ip_address" != "$new_ip_address" ]; then 321 delete_old_address 322 delete_old_routes 323 fi 324 fi 325 if [ "$reason" = BOUND ] || \ 326 [ "$reason" = REBOOT ] || \ 327 [ -z "$old_ip_address" ] || \ 328 [ "$old_ip_address" != "$new_ip_address" ]; then 329 add_new_address 330 add_new_routes 331 fi 332 if [ "$new_ip_address" != "$alias_ip_address" ]; then 333 add_new_alias 334 fi 335 if is_default_interface; then 336 add_new_resolv_conf 337 fi 338 ;; 339 340EXPIRE|FAIL) 341 delete_old_alias 342 if [ -n "$old_ip_address" ]; then 343 delete_old_address 344 delete_old_routes 345 fi 346 if [ -x $ARP ]; then 347 $ARP -d -a -i $interface 348 fi 349 # XXX Why add alias we just deleted above? 350 add_new_alias 351 if is_default_interface; then 352 if [ -f /etc/resolv.conf.save ]; then 353 cat /etc/resolv.conf.save > /etc/resolv.conf 354 fi 355 fi 356 ;; 357 358TIMEOUT) 359 delete_old_alias 360 add_new_address 361 sleep 1 362 if [ -n "$new_routers" ]; then 363 $LOGGER "New Routers ($interface): $new_routers" 364 set "$new_routers" 365 if ping -q -c 1 -t 1 "$1"; then 366 if [ "$new_ip_address" != "$alias_ip_address" ]; then 367 add_new_alias 368 fi 369 add_new_routes 370 if ! is_default_interface; then 371 exit_with_hooks 0 372 fi 373 if add_new_resolv_conf; then 374 exit_with_hooks 0 375 fi 376 fi 377 fi 378 eval "$IFCONFIG $interface inet -alias $new_ip_address $medium" 379 delete_old_routes 380 exit_with_hooks 1 381 ;; 382esac 383 384exit_with_hooks 0 385