sbin/dhclient/dhclient-script

   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
  22 ARP=/usr/sbin/arp
  23 HOSTNAME=/bin/hostname
  24 IFCONFIG='/sbin/ifconfig -n'
  25
  26 LOCALHOST=127.0.0.1
  27
  28 if [ -x /usr/bin/logger ]; then
  29         LOGGER="/usr/bin/logger -s -p user.notice -t dhclient"
  30 else
  31         LOGGER=echo
  32 fi
  33
  34 #
  35 # Helper functions that implement common actions.
  36 #
  37
  38 check_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
  50 arp_flush() {
  51         arp -an -i $interface | \
  52                 sed -n -e 's/^.*(\(.*\)) at .*$/arp -d \1/p' | \
  53                 sh >/dev/null 2>&1
  54 }
  55
  56 delete_old_address() {
  57         eval "$IFCONFIG $interface inet -alias $old_ip_address $medium"
  58 }
  59
  60 add_new_address() {
  61         eval "$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): $new_routers"
  71 }
  72
  73 delete_old_alias() {
  74         if [ -n "$alias_ip_address" ]; then
  75                 $IFCONFIG $interface inet -alias $alias_ip_address > /dev/null 2>&1
  76                 #route delete $alias_ip_address $LOCALHOST > /dev/null 2>&1
  77         fi
  78 }
  79
  80 add_new_alias() {
  81         if [ -n "$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
  88 fill_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 $router"
 109                 shift; shift; shift; shift
 110         done
 111 }
 112
 113 delete_old_routes() {
 114         #route delete "$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
 143 add_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
 194 add_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_search" ]; then
 205                 echo "search $new_domain_search" >>$tmpres
 206         elif [ -n "$new_domain_name" ]; then
 207                 echo "search $new_domain_name" >>$tmpres
 208         fi
 209
 210         if [ -n "$new_domain_name_servers" ]; then
 211                 for nameserver in $new_domain_name_servers; do
 212                         echo "nameserver $nameserver" >>$tmpres
 213                 done
 214         fi
 215
 216         if [ -f $tmpres ]; then
 217                 if [ -f /etc/resolv.conf.tail ]; then
 218                         cat /etc/resolv.conf.tail >>$tmpres
 219                 fi
 220
 221                 # When resolv.conf is not changed actually, we don't
 222                 # need to update it.
 223                 # If /usr is not mounted yet, we cannot use cmp, then
 224                 # the following test fails.  In such case, we simply
 225                 # ignore an error and do update resolv.conf.
 226                 if cmp -s $tmpres /etc/resolv.conf; then
 227                         rm -f $tmpres
 228                         return 0
 229                 fi 2>/dev/null
 230
 231                 # In case (e.g. during OpenBSD installs) /etc/resolv.conf
 232                 # is a symbolic link, take care to preserve the link and write
 233                 # the new data in the correct location.
 234
 235                 if [ -f /etc/resolv.conf ]; then
 236                         cat /etc/resolv.conf > /etc/resolv.conf.save
 237                 fi
 238                 cat $tmpres > /etc/resolv.conf
 239                 rm -f $tmpres
 240
 241                 # Try to ensure correct ownership and permissions.
 242                 chown -RL root:wheel /etc/resolv.conf
 243                 chmod -RL 644 /etc/resolv.conf
 244
 245                 return 0
 246         fi
 247
 248         return 1
 249 }
 250
 251 # Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
 252 exit_with_hooks() {
 253         exit_status=$1
 254         if [ -f /etc/dhclient-exit-hooks ]; then
 255                 . /etc/dhclient-exit-hooks
 256         fi
 257         # probably should do something with exit status of the local script
 258         exit $exit_status
 259 }
 260
 261 # Get the interface with the current ipv4 default route on it using only
 262 # commands that are available prior to /usr being mounted.
 263 is_default_interface()
 264 {
 265         routeget="`route -n get -inet default`"
 266         oldifs="$IFS"
 267         IFS="
 268 "
 269         defif=
 270         for line in $routeget ; do
 271                 case $line in
 272                 *interface:*)
 273                         defif=${line##*: }
 274                         ;;
 275                 esac
 276         done
 277         IFS=${oldifs}
 278
 279         if [ -z "$defif" -o "$defif" = "$interface" ]; then
 280                 return 0
 281         else
 282                 return 1
 283         fi
 284 }
 285
 286 #
 287 # Start of active code.
 288 #
 289
 290 # Invoke the local dhcp client enter hooks, if they exist.
 291 if [ -f /etc/dhclient-enter-hooks ]; then
 292         exit_status=0
 293         . /etc/dhclient-enter-hooks
 294         # allow the local script to abort processing of this state
 295         # local script must set exit_status variable to nonzero.
 296         if [ $exit_status -ne 0 ]; then
 297                 exit $exit_status
 298         fi
 299 fi
 300
 301 case $reason in
 302 MEDIUM)
 303         eval "$IFCONFIG $interface $medium"
 304         eval "$IFCONFIG $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1
 305         sleep 1
 306         ;;
 307
 308 PREINIT)
 309         delete_old_alias
 310         $IFCONFIG $interface inet alias 0.0.0.0 netmask 255.0.0.0 broadcast 255.255.255.255 up
 311         ;;
 312
 313 ARPCHECK|ARPSEND)
 314         ;;
 315
 316 BOUND|RENEW|REBIND|REBOOT)
 317         check_hostname
 318         if [ -n "$old_ip_address" ]; then
 319                 if [ "$old_ip_address" != "$alias_ip_address" ]; then
 320                         delete_old_alias
 321                 fi
 322                 if [ "$old_ip_address" != "$new_ip_address" ]; then
 323                         delete_old_address
 324                         delete_old_routes
 325                 fi
 326         fi
 327         if [ "$reason" = BOUND ] || \
 328            [ "$reason" = REBOOT ] || \
 329            [ -z "$old_ip_address" ] || \
 330            [ "$old_ip_address" != "$new_ip_address" ]; then
 331                 add_new_address
 332                 add_new_routes
 333         fi
 334         if [ "$new_ip_address" != "$alias_ip_address" ]; then
 335                 add_new_alias
 336         fi
 337         if is_default_interface; then
 338                 add_new_resolv_conf
 339         fi
 340         ;;
 341
 342 EXPIRE|FAIL)
 343         delete_old_alias
 344         if [ -n "$old_ip_address" ]; then
 345                 delete_old_address
 346                 delete_old_routes
 347         fi
 348         if [ -x $ARP ]; then
 349                 $ARP -d -a -i $interface
 350         fi
 351         # XXX Why add alias we just deleted above?
 352         add_new_alias
 353         if is_default_interface; then
 354                 if [ -f /etc/resolv.conf.save ]; then
 355                         cat /etc/resolv.conf.save > /etc/resolv.conf
 356                 fi
 357         fi
 358         ;;
 359
 360 TIMEOUT)
 361         delete_old_alias
 362         add_new_address
 363         sleep 1
 364         if [ -n "$new_routers" ]; then
 365                 $LOGGER "New Routers ($interface): $new_routers"
 366                 set "$new_routers"
 367                 if ping -q -c 1 -t 1 "$1"; then
 368                         if [ "$new_ip_address" != "$alias_ip_address" ]; then
 369                                 add_new_alias
 370                         fi
 371                         add_new_routes
 372                         if ! is_default_interface; then
 373                                 exit_with_hooks 0
 374                         fi
 375                         if add_new_resolv_conf; then
 376                                 exit_with_hooks 0
 377                         fi
 378                 fi
 379         fi
 380         eval "$IFCONFIG $interface inet -alias $new_ip_address $medium"
 381         delete_old_routes
 382         exit_with_hooks 1
 383         ;;
 384 esac
 385
 386 exit_with_hooks 0