dhclient-script revision 175554
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 175554 2008-01-21 23:54:57Z 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 23AWK=/usr/bin/awk 24HOSTNAME=/bin/hostname 25IFCONFIG='/sbin/ifconfig -n' 26NETSTAT=/usr/bin/netstat 27 28LOCALHOST=127.0.0.1 29 30if [ -x /usr/bin/logger ]; then 31 LOGGER="/usr/bin/logger -s -p user.notice -t dhclient" 32else 33 LOGGER=echo 34fi 35 36# 37# Helper functions that implement common actions. 38# 39 40check_hostname() { 41 current_hostname=`$HOSTNAME` 42 if [ -z "$current_hostname" ]; then 43 $LOGGER "New Hostname ($interface): $new_host_name" 44 $HOSTNAME $new_host_name 45 elif [ "$current_hostname" = "$old_host_name" -a \ 46 "$new_host_name" != "$old_host_name" ]; then 47 $LOGGER "New Hostname ($interface): $new_host_name" 48 $HOSTNAME $new_host_name 49 fi 50} 51 52arp_flush() { 53 arp -an -i $interface | \ 54 sed -n -e 's/^.*(\(.*\)) at .*$/arp -d \1/p' | \ 55 sh >/dev/null 2>&1 56} 57 58delete_old_address() { 59 eval "$IFCONFIG $interface inet -alias $old_ip_address $medium" 60} 61 62add_new_address() { 63 eval "$IFCONFIG $interface \ 64 inet $new_ip_address \ 65 netmask $new_subnet_mask \ 66 broadcast $new_broadcast_address \ 67 $medium" 68 69 $LOGGER "New IP Address ($interface): $new_ip_address" 70 $LOGGER "New Subnet Mask ($interface): $new_subnet_mask" 71 $LOGGER "New Broadcast Address ($interface): $new_broadcast_address" 72 $LOGGER "New Routers ($interface): $new_routers" 73} 74 75delete_old_alias() { 76 if [ -n "$alias_ip_address" ]; then 77 $IFCONFIG $interface inet -alias $alias_ip_address > /dev/null 2>&1 78 #route delete $alias_ip_address $LOCALHOST > /dev/null 2>&1 79 fi 80} 81 82add_new_alias() { 83 if [ -n "$alias_ip_address" ]; then 84 $IFCONFIG $interface inet alias $alias_ip_address netmask \ 85 $alias_subnet_mask 86 #route add $alias_ip_address $LOCALHOST 87 fi 88} 89 90fill_classless_routes() { 91 set $1 92 while [ $# -ge 5 ]; do 93 if [ $1 -eq 0 ]; then 94 route="default" 95 elif [ $1 -le 8 ]; then 96 route="$2.0.0.0/$1" 97 shift 98 elif [ $1 -le 16 ]; then 99 route="$2.$3.0.0/$1" 100 shift; shift 101 elif [ $1 -le 24 ]; then 102 route="$2.$3.$4.0/$1" 103 shift; shift; shift 104 else 105 route="$2.$3.$4.$5/$1" 106 shift; shift; shift; shift 107 fi 108 shift 109 router="$1.$2.$3.$4" 110 classless_routes="$classless_routes $route $router" 111 shift; shift; shift; shift 112 done 113} 114 115delete_old_routes() { 116 #route delete "$old_ip_address" $LOCALHOST >/dev/null 2>&1 117 if [ -n "$old_classless_routes" ]; then 118 fill_classless_routes "$old_classless_routes" 119 set $classless_routes 120 while [ $# -gt 1 ]; do 121 route delete "$1" "$2" 122 shift; shift 123 done 124 return 0; 125 fi 126 127 for router in $old_routers; do 128 if [ $if_defaultroute = x -o $if_defaultroute = $interface ]; then 129 route delete default $route >/dev/null 2>&1 130 fi 131 done 132 133 if [ -n "$old_static_routes" ]; then 134 set $old_static_routes 135 while [ $# -gt 1 ]; do 136 route delete "$1" "$2" 137 shift; shift 138 done 139 fi 140 141 arp_flush 142} 143 144add_new_routes() { 145 #route add $new_ip_address $LOCALHOST >/dev/null 2>&1 146 147 # RFC 3442: If the DHCP server returns both a Classless Static 148 # Routes option and a Router option, the DHCP client MUST ignore 149 # the Router option. 150 # 151 # DHCP clients that support this option (Classless Static Routes) 152 # MUST NOT install the routes specified in the Static Routes 153 # option (option code 33) if both a Static Routes option and the 154 # Classless Static Routes option are provided. 155 156 if [ -n "$new_classless_routes" ]; then 157 fill_classless_routes "$new_classless_routes" 158 $LOGGER "New Classless Static Routes ($interface): $classless_routes" 159 set $classless_routes 160 while [ $# -gt 1 ]; do 161 if [ "0.0.0.0" = "$2" ]; then 162 route add "$1" -iface "$interface" 163 else 164 route add "$1" "$2" 165 fi 166 shift; shift 167 done 168 return 169 fi 170 171 for router in $new_routers; do 172 if [ "$new_ip_address" = "$router" ]; then 173 route add default -iface $router >/dev/null 2>&1 174 else 175 route add default $router >/dev/null 2>&1 176 fi 177 # 2nd and subsequent default routers error out, so explicitly 178 # stop processing the list after the first one. 179 break 180 done 181 182 if [ -n "$new_static_routes" ]; then 183 $LOGGER "New Static Routes ($interface): $new_static_routes" 184 set $new_static_routes 185 while [ $# -gt 1 ]; do 186 route add $1 $2 187 shift; shift 188 done 189 fi 190} 191 192add_new_resolv_conf() { 193 # XXX Old code did not create/update resolv.conf unless both 194 # $new_domain_name and $new_domain_name_servers were provided. PR 195 # #3135 reported some ISP's only provide $new_domain_name_servers and 196 # thus broke the script. This code creates the resolv.conf if either 197 # are provided. 198 199 local tmpres=/var/run/resolv.conf.${interface} 200 rm -f $tmpres 201 202 if [ -n "$new_domain_name" ]; then 203 echo "search $new_domain_name" >>$tmpres 204 fi 205 206 if [ -n "$new_domain_name_servers" ]; then 207 for nameserver in $new_domain_name_servers; do 208 echo "nameserver $nameserver" >>$tmpres 209 done 210 fi 211 212 if [ -f $tmpres ]; then 213 if [ -f /etc/resolv.conf.tail ]; then 214 cat /etc/resolv.conf.tail >>$tmpres 215 fi 216 217 # When resolv.conf is not changed actually, we don't 218 # need to update it. 219 # If /usr is not mounted yet, we cannot use cmp, then 220 # the following test fails. In such case, we simply 221 # ignore an error and do update resolv.conf. 222 if cmp -s $tmpres /etc/resolv.conf; then 223 rm -f $tmpres 224 return 0 225 fi 2>/dev/null 226 227 # In case (e.g. during OpenBSD installs) /etc/resolv.conf 228 # is a symbolic link, take care to preserve the link and write 229 # the new data in the correct location. 230 231 if [ -f /etc/resolv.conf ]; then 232 cat /etc/resolv.conf > /etc/resolv.conf.save 233 fi 234 cat $tmpres > /etc/resolv.conf 235 rm -f $tmpres 236 237 # Try to ensure correct ownership and permissions. 238 chown -RL root:wheel /etc/resolv.conf 239 chmod -RL 644 /etc/resolv.conf 240 241 return 0 242 fi 243 244 return 1 245} 246 247# Must be used on exit. Invokes the local dhcp client exit hooks, if any. 248exit_with_hooks() { 249 exit_status=$1 250 if [ -f /etc/dhclient-exit-hooks ]; then 251 . /etc/dhclient-exit-hooks 252 fi 253 # probably should do something with exit status of the local script 254 exit $exit_status 255} 256 257# 258# Start of active code. 259# 260 261# Invoke the local dhcp client enter hooks, if they exist. 262if [ -f /etc/dhclient-enter-hooks ]; then 263 exit_status=0 264 . /etc/dhclient-enter-hooks 265 # allow the local script to abort processing of this state 266 # local script must set exit_status variable to nonzero. 267 if [ $exit_status -ne 0 ]; then 268 exit $exit_status 269 fi 270fi 271 272if [ -x $NETSTAT ]; then 273 if_defaultroute=`$NETSTAT -rnf inet | $AWK '{if ($1=="default") printf $6}'` 274else 275 if_defaultroute="x" 276fi 277 278case $reason in 279MEDIUM) 280 eval "$IFCONFIG $interface $medium" 281 eval "$IFCONFIG $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1 282 sleep 1 283 ;; 284 285PREINIT) 286 delete_old_alias 287 $IFCONFIG $interface inet alias 0.0.0.0 netmask 0.0.0.0 broadcast 255.255.255.255 up 288 ;; 289 290ARPCHECK|ARPSEND) 291 ;; 292 293BOUND|RENEW|REBIND|REBOOT) 294 check_hostname 295 if [ -n "$old_ip_address" ]; then 296 if [ "$old_ip_address" != "$alias_ip_address" ]; then 297 delete_old_alias 298 fi 299 if [ "$old_ip_address" != "$new_ip_address" ]; then 300 delete_old_address 301 delete_old_routes 302 fi 303 fi 304 if [ "$reason" = BOUND ] || \ 305 [ "$reason" = REBOOT ] || \ 306 [ -z "$old_ip_address" ] || \ 307 [ "$old_ip_address" != "$new_ip_address" ]; then 308 add_new_address 309 add_new_routes 310 fi 311 if [ "$new_ip_address" != "$alias_ip_address" ]; then 312 add_new_alias 313 fi 314 add_new_resolv_conf 315 ;; 316 317EXPIRE|FAIL) 318 delete_old_alias 319 if [ -n "$old_ip_address" ]; then 320 delete_old_address 321 delete_old_routes 322 fi 323 if [ -x $ARP ]; then 324 $ARP -d -a -i $interface 325 fi 326 # XXX Why add alias we just deleted above? 327 add_new_alias 328 if [ -f /etc/resolv.conf.save ]; then 329 cat /etc/resolv.conf.save > /etc/resolv.conf 330 fi 331 ;; 332 333TIMEOUT) 334 delete_old_alias 335 add_new_address 336 sleep 1 337 if [ -n "$new_routers" ]; then 338 $LOGGER "New Routers ($interface): $new_routers" 339 set "$new_routers" 340 if ping -q -c 1 -t 1 "$1"; then 341 if [ "$new_ip_address" != "$alias_ip_address" ]; then 342 add_new_alias 343 fi 344 add_new_routes 345 if add_new_resolv_conf; then 346 exit_with_hooks 0 347 fi 348 fi 349 fi 350 eval "$IFCONFIG $interface inet -alias $new_ip_address $medium" 351 delete_old_routes 352 exit_with_hooks 1 353 ;; 354esac 355 356exit_with_hooks 0 357