1#!/bin/sh 2# 3# $OpenBSD: dhclient-script,v 1.6 2004/05/06 18:22:41 claudio Exp $ 4# $FreeBSD$ 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 $router >/dev/null 2>&1 175 else 176 if [ "$new_subnet_mask" = "255.255.255.255" ]; then 177 route add "$router" -iface "$interface" >/dev/null 2>&1 178 fi 179 180 route add default $router >/dev/null 2>&1 181 fi 182 fi 183 # 2nd and subsequent default routers error out, so explicitly 184 # stop processing the list after the first one. 185 break 186 done 187 188 if [ -n "$new_static_routes" ]; then 189 $LOGGER "New Static Routes ($interface): $new_static_routes" 190 set $new_static_routes 191 while [ $# -gt 1 ]; do 192 route add $1 $2 193 shift; shift 194 done 195 fi 196} 197 198add_new_resolv_conf() { 199 # XXX Old code did not create/update resolv.conf unless both 200 # $new_domain_name and $new_domain_name_servers were provided. PR 201 # #3135 reported some ISP's only provide $new_domain_name_servers and 202 # thus broke the script. This code creates the resolv.conf if either 203 # are provided. 204 205 local tmpres=/var/run/resolv.conf.${interface} 206 rm -f $tmpres 207 208 if [ -n "$new_domain_search" ]; then 209 echo "search $new_domain_search" >>$tmpres 210 elif [ -n "$new_domain_name" ]; then 211 echo "search $new_domain_name" >>$tmpres 212 fi 213 214 if [ -n "$new_domain_name_servers" ]; then 215 for nameserver in $new_domain_name_servers; do 216 echo "nameserver $nameserver" >>$tmpres 217 done 218 fi 219 220 if [ -f $tmpres ]; then 221 if [ -f /etc/resolv.conf.tail ]; then 222 cat /etc/resolv.conf.tail >>$tmpres 223 fi 224 225 case $resolvconf_enable in 226 # "no", "false", "off", or "0" 227 [Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0) 228 # When resolv.conf is not changed actually, we don't 229 # need to update it. 230 # If /usr is not mounted yet, we cannot use cmp, then 231 # the following test fails. In such case, we simply 232 # ignore an error and do update resolv.conf. 233 if cmp -s $tmpres /etc/resolv.conf; then 234 rm -f $tmpres 235 return 0 236 fi 2>/dev/null 237 238 # In case (e.g. during OpenBSD installs) 239 # /etc/resolv.conf is a symbolic link, take 240 # care to preserve the link and write the new 241 # data in the correct location. 242 243 if [ -f /etc/resolv.conf ]; then 244 cat /etc/resolv.conf > /etc/resolv.conf.save 245 fi 246 cat $tmpres > /etc/resolv.conf 247 248 # Try to ensure correct ownership and permissions. 249 chown -RL root:wheel /etc/resolv.conf 250 chmod -RL 644 /etc/resolv.conf 251 ;; 252 253 *) 254 /sbin/resolvconf -a ${interface} < $tmpres 255 ;; 256 esac 257 258 rm -f $tmpres 259 260 return 0 261 fi 262 263 return 1 264} 265 266# Must be used on exit. Invokes the local dhcp client exit hooks, if any. 267exit_with_hooks() { 268 exit_status=$1 269 if [ -f /etc/dhclient-exit-hooks ]; then 270 . /etc/dhclient-exit-hooks 271 fi 272 # probably should do something with exit status of the local script 273 exit $exit_status 274} 275 276# Get the interface with the current ipv4 default route on it using only 277# commands that are available prior to /usr being mounted. 278is_default_interface() 279{ 280 routeget="`route -n get -inet default`" 281 oldifs="$IFS" 282 IFS=" 283" 284 defif= 285 for line in $routeget ; do 286 case $line in 287 *interface:*) 288 defif=${line##*: } 289 ;; 290 esac 291 done 292 IFS=${oldifs} 293 294 if [ -z "$defif" -o "$defif" = "$interface" ]; then 295 return 0 296 else 297 return 1 298 fi 299} 300 301# 302# Start of active code. 303# 304 305# Invoke the local dhcp client enter hooks, if they exist. 306if [ -f /etc/dhclient-enter-hooks ]; then 307 exit_status=0 308 . /etc/dhclient-enter-hooks 309 # allow the local script to abort processing of this state 310 # local script must set exit_status variable to nonzero. 311 if [ $exit_status -ne 0 ]; then 312 exit $exit_status 313 fi 314fi 315 316: ${resolvconf_enable="YES"} 317 318case $reason in 319MEDIUM) 320 eval "$IFCONFIG $interface $medium" 321 sleep 1 322 ;; 323 324PREINIT) 325 delete_old_alias 326 eval "$IFCONFIG $interface up" 327 ;; 328 329ARPCHECK|ARPSEND) 330 ;; 331 332BOUND|RENEW|REBIND|REBOOT) 333 check_hostname 334 if [ -n "$old_ip_address" ]; then 335 if [ "$old_ip_address" != "$alias_ip_address" ]; then 336 delete_old_alias 337 fi 338 if [ "$old_ip_address" != "$new_ip_address" ]; then 339 delete_old_address 340 delete_old_routes 341 fi 342 fi 343 if [ "$reason" = BOUND ] || \ 344 [ "$reason" = REBOOT ] || \ 345 [ -z "$old_ip_address" ] || \ 346 [ "$old_ip_address" != "$new_ip_address" ]; then 347 add_new_address 348 add_new_routes 349 fi 350 if [ "$new_ip_address" != "$alias_ip_address" ]; then 351 add_new_alias 352 fi 353 if is_default_interface; then 354 add_new_resolv_conf 355 fi 356 ;; 357 358EXPIRE|FAIL) 359 delete_old_alias 360 if [ -n "$old_ip_address" ]; then 361 delete_old_address 362 delete_old_routes 363 fi 364 if [ -x $ARP ]; then 365 $ARP -d -a -i $interface 366 fi 367 # XXX Why add alias we just deleted above? 368 add_new_alias 369 if is_default_interface; then 370 case $resolvconf_enable in 371 # "no", "false", "off", or "0" 372 [Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0) 373 if [ -f /etc/resolv.conf.save ]; then 374 cat /etc/resolv.conf.save > /etc/resolv.conf 375 fi 376 ;; 377 *) 378 /sbin/resolvconf -d ${interface} 379 ;; 380 esac 381 fi 382 ;; 383 384TIMEOUT) 385 delete_old_alias 386 add_new_address 387 sleep 1 388 if [ -n "$new_routers" ]; then 389 $LOGGER "New Routers ($interface): $new_routers" 390 set "$new_routers" 391 if ping -q -c 1 -t 1 "$1"; then 392 if [ "$new_ip_address" != "$alias_ip_address" ]; then 393 add_new_alias 394 fi 395 add_new_routes 396 if ! is_default_interface; then 397 exit_with_hooks 0 398 fi 399 if add_new_resolv_conf; then 400 exit_with_hooks 0 401 fi 402 fi 403 fi 404 eval "$IFCONFIG $interface inet -alias $new_ip_address $medium" 405 delete_old_routes 406 exit_with_hooks 1 407 ;; 408esac 409 410exit_with_hooks 0 411