dhclient-script revision 166602
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 166602 2007-02-09 17:50:26Z emaste $ 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 25NETSTAT=/usr/bin/netstat 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 eval "ifconfig $interface inet -alias $old_ip_address $medium" 59} 60 61add_new_address() { 62 eval "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 89fill_classless_routes() { 90 set $1 91 while [ $# -gt 5 ]; do 92 if [ $1 -eq 0 ]; then 93 route="default" 94 elif [ $1 -le 8 ]; then 95 route="$2.0.0.0/$1" 96 shift 97 elif [ $1 -le 16 ]; then 98 route="$2.$3.0.0/$1" 99 shift; shift 100 elif [ $1 -le 24 ]; then 101 route="$2.$3.$4.0/$1" 102 shift; shift; shift 103 else 104 route="$2.$3.$4.$5/$1" 105 shift; shift; shift; shift 106 fi 107 shift 108 router="$1.$2.$3.$4" 109 classless_routes="$classless_routes $route $router" 110 shift; shift; shift; shift 111 done 112} 113 114delete_old_routes() { 115 #route delete "$old_ip_address" $LOCALHOST >/dev/null 2>&1 116 if [ -n "$old_classless_routes" ]; then 117 fill_classless_routes "$old_classless_routes" 118 set $classless_routes 119 while [ $# -gt 1 ]; do 120 route delete "$1" "$2" 121 shift; shift 122 done 123 return 0; 124 fi 125 126 for router in $old_routers; do 127 if [ $if_defaultroute = x -o $if_defaultroute = $interface ]; then 128 route delete default $route >/dev/null 2>&1 129 fi 130 done 131 132 if [ -n "$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 $new_routers; do 171 if [ "$new_ip_address" = "$router" ]; then 172 route add default -iface $router >/dev/null 2>&1 173 else 174 route add default $router >/dev/null 2>&1 175 fi 176 # 2nd and subsequent default routers error out, so explicitly 177 # stop processing the list after the first one. 178 break 179 done 180 181 if [ -n "$new_static_routes" ]; then 182 $LOGGER "New Static Routes ($interface): $new_static_routes" 183 set $new_static_routes 184 while [ $# -gt 1 ]; do 185 route add $1 $2 186 shift; shift 187 done 188 fi 189} 190 191add_new_resolv_conf() { 192 # XXX Old code did not create/update resolv.conf unless both 193 # $new_domain_name and $new_domain_name_servers were provided. PR 194 # #3135 reported some ISP's only provide $new_domain_name_servers and 195 # thus broke the script. This code creates the resolv.conf if either 196 # are provided. 197 198 local tmpres=/var/run/resolv.conf.${interface} 199 rm -f $tmpres 200 201 if [ -n "$new_domain_name" ]; then 202 echo "search $new_domain_name" >>$tmpres 203 fi 204 205 if [ -n "$new_domain_name_servers" ]; then 206 for nameserver in $new_domain_name_servers; do 207 echo "nameserver $nameserver" >>$tmpres 208 done 209 fi 210 211 if [ -f $tmpres ]; then 212 if [ -f /etc/resolv.conf.tail ]; then 213 cat /etc/resolv.conf.tail >>$tmpres 214 fi 215 216 # When resolv.conf is not changed actually, we don't 217 # need to update it. 218 # If /usr is not mounted yet, we cannot use cmp, then 219 # the following test fails. In such case, we simply 220 # ignore an error and do update resolv.conf. 221 if cmp -s $tmpres /etc/resolv.conf; then 222 rm -f $tmpres 223 return 0 224 fi 2>/dev/null 225 226 # In case (e.g. during OpenBSD installs) /etc/resolv.conf 227 # is a symbolic link, take care to preserve the link and write 228 # the new data in the correct location. 229 230 if [ -f /etc/resolv.conf ]; then 231 cat /etc/resolv.conf > /etc/resolv.conf.save 232 fi 233 cat $tmpres > /etc/resolv.conf 234 rm -f $tmpres 235 236 # Try to ensure correct ownership and permissions. 237 chown -RL root:wheel /etc/resolv.conf 238 chmod -RL 644 /etc/resolv.conf 239 240 return 0 241 fi 242 243 return 1 244} 245 246# Must be used on exit. Invokes the local dhcp client exit hooks, if any. 247exit_with_hooks() { 248 exit_status=$1 249 if [ -f /etc/dhclient-exit-hooks ]; then 250 . /etc/dhclient-exit-hooks 251 fi 252 # probably should do something with exit status of the local script 253 exit $exit_status 254} 255 256# 257# Start of active code. 258# 259 260# Invoke the local dhcp client enter hooks, if they exist. 261if [ -f /etc/dhclient-enter-hooks ]; then 262 exit_status=0 263 . /etc/dhclient-enter-hooks 264 # allow the local script to abort processing of this state 265 # local script must set exit_status variable to nonzero. 266 if [ $exit_status -ne 0 ]; then 267 exit $exit_status 268 fi 269fi 270 271if [ -x $NETSTAT ]; then 272 if_defaultroute=`$NETSTAT -rnf inet | $AWK '{if ($1=="default") printf $6}'` 273else 274 if_defaultroute="x" 275fi 276 277case $reason in 278MEDIUM) 279 eval "ifconfig $interface $medium" 280 eval "ifconfig $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1 281 sleep 1 282 ;; 283 284PREINIT) 285 delete_old_alias 286 ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 broadcast 255.255.255.255 up 287 ;; 288 289ARPCHECK|ARPSEND) 290 ;; 291 292BOUND|RENEW|REBIND|REBOOT) 293 check_hostname 294 if [ -n "$old_ip_address" ]; then 295 if [ "$old_ip_address" != "$alias_ip_address" ]; then 296 delete_old_alias 297 fi 298 if [ "$old_ip_address" != "$new_ip_address" ]; then 299 delete_old_address 300 delete_old_routes 301 fi 302 fi 303 if [ "$reason" = BOUND ] || \ 304 [ "$reason" = REBOOT ] || \ 305 [ -z "$old_ip_address" ] || \ 306 [ "$old_ip_address" != "$new_ip_address" ]; then 307 add_new_address 308 add_new_routes 309 fi 310 if [ "$new_ip_address" != "$alias_ip_address" ]; then 311 add_new_alias 312 fi 313 add_new_resolv_conf 314 ;; 315 316EXPIRE|FAIL) 317 delete_old_alias 318 if [ -n "$old_ip_address" ]; then 319 delete_old_address 320 delete_old_routes 321 fi 322 if [ -x $ARP ]; then 323 $ARP -d -a -i $interface 324 fi 325 # XXX Why add alias we just deleted above? 326 add_new_alias 327 if [ -f /etc/resolv.conf.save ]; then 328 cat /etc/resolv.conf.save > /etc/resolv.conf 329 fi 330 ;; 331 332TIMEOUT) 333 delete_old_alias 334 add_new_address 335 sleep 1 336 if [ -n "$new_routers" ]; then 337 $LOGGER "New Routers ($interface): $new_routers" 338 set "$new_routers" 339 if ping -q -c 1 -t 1 "$1"; then 340 if [ "$new_ip_address" != "$alias_ip_address" ]; then 341 add_new_alias 342 fi 343 add_new_routes 344 if add_new_resolv_conf; then 345 exit_with_hooks 0 346 fi 347 fi 348 fi 349 eval "ifconfig $interface inet -alias $new_ip_address $medium" 350 delete_old_routes 351 exit_with_hooks 1 352 ;; 353esac 354 355exit_with_hooks 0 356