sbin/dhclient/dhclient-script

   1 #!/bin/sh
   2 #
   3 # $OpenBSD: dhclient-script,v 1.6 2004/05/06 18:22:41 claudio Exp $
   4 #
   5 # Copyright (c) 2003 Kenneth R Westerback <krw@openbsd.org>
   6 #
   7 # Permission to use, copy, modify, and distribute this software for any
   8 # purpose with or without fee is hereby granted, provided that the above
   9 # copyright notice and this permission notice appear in all copies.
  10 #
  11 # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18 #
  19 #
  20
  21 ARP=/usr/sbin/arp
  22 HOSTNAME=/bin/hostname
  23 IFCONFIG='/sbin/ifconfig -n'
  24
  25 LOCALHOST=127.0.0.1
  26
  27 if [ -x /usr/bin/logger ]; then
  28         LOGGER="/usr/bin/logger -s -p user.notice -t dhclient"
  29 else
  30         LOGGER=echo
  31 fi
  32
  33 #
  34 # Helper functions that implement common actions.
  35 #
  36
  37 check_hostname() {
  38         current_hostname=`$HOSTNAME`
  39         if [ -z "$current_hostname" ]; then
  40                 $LOGGER "New Hostname ($interface): $new_host_name"
  41                 $HOSTNAME $new_host_name
  42         elif [ "$current_hostname" = "$old_host_name" -a \
  43                "$new_host_name" != "$old_host_name" ]; then
  44                 $LOGGER "New Hostname ($interface): $new_host_name"
  45                 $HOSTNAME $new_host_name
  46         fi
  47 }
  48
  49 arp_flush() {
  50         arp -an -i $interface | \
  51                 sed -n -e 's/^.*(\(.*\)) at .*$/arp -d \1/p' | \
  52                 sh >/dev/null 2>&1
  53 }
  54
  55 delete_old_address() {
  56         eval "$IFCONFIG $interface inet -alias $old_ip_address $medium"
  57 }
  58
  59 add_new_address() {
  60         eval "$IFCONFIG $interface \
  61                 inet $new_ip_address \
  62                 netmask $new_subnet_mask \
  63                 broadcast $new_broadcast_address \
  64                 $medium"
  65
  66         $LOGGER "New IP Address ($interface): $new_ip_address"
  67         $LOGGER "New Subnet Mask ($interface): $new_subnet_mask"
  68         $LOGGER "New Broadcast Address ($interface): $new_broadcast_address"
  69         $LOGGER "New Routers ($interface): $new_routers"
  70 }
  71
  72 delete_old_alias() {
  73         if [ -n "$alias_ip_address" ]; then
  74                 $IFCONFIG $interface inet -alias $alias_ip_address > /dev/null 2>&1
  75                 #route delete $alias_ip_address $LOCALHOST > /dev/null 2>&1
  76         fi
  77 }
  78
  79 add_new_alias() {
  80         if [ -n "$alias_ip_address" ]; then
  81                 $IFCONFIG $interface inet alias $alias_ip_address netmask \
  82                     $alias_subnet_mask
  83                 #route add $alias_ip_address $LOCALHOST
  84         fi
  85 }
  86
  87 fill_classless_routes() {
  88         set $1
  89         while [ $# -ge 5 ]; do
  90                 if [ $1 -eq 0 ]; then
  91                         route="default"
  92                 elif [ $1 -le 8 ]; then
  93                         route="$2.0.0.0/$1"
  94                         shift
  95                 elif [ $1 -le 16 ]; then
  96                         route="$2.$3.0.0/$1"
  97                         shift; shift
  98                 elif [ $1 -le 24 ]; then
  99                         route="$2.$3.$4.0/$1"
 100                         shift; shift; shift
 101                 else
 102                         route="$2.$3.$4.$5/$1"
 103                         shift; shift; shift; shift
 104                 fi
 105                 shift
 106                 router="$1.$2.$3.$4"
 107                 classless_routes="$classless_routes $route $router"
 108                 shift; shift; shift; shift
 109         done
 110 }
 111
 112 delete_old_routes() {
 113         #route delete "$old_ip_address" $LOCALHOST >/dev/null 2>&1
 114         if [ -n "$old_classless_routes" ]; then
 115                 fill_classless_routes "$old_classless_routes"
 116                 set $classless_routes
 117                 while [ $# -gt 1 ]; do
 118                         route delete "$1" "$2"
 119                         shift; shift
 120                 done
 121                 return 0;
 122         fi
 123
 124         # If we supported multiple default routes, we'd be removing each
 125         # one here.  We don't so just delete the default route if it's
 126         # through our interface.
 127         if is_default_interface; then
 128                 route delete default >/dev/null 2>&1
 129         fi
 130
 131         if [ -n "$old_static_routes" ]; then
 132                 set $old_static_routes
 133                 while [ $# -gt 1 ]; do
 134                         route delete "$1" "$2"
 135                         shift; shift
 136                 done
 137         fi
 138
 139         arp_flush
 140 }
 141
 142 add_new_routes() {
 143         #route add $new_ip_address $LOCALHOST >/dev/null 2>&1
 144
 145         # RFC 3442: If the DHCP server returns both a Classless Static
 146         # Routes option and a Router option, the DHCP client MUST ignore
 147         # the Router option.
 148         #
 149         # DHCP clients that support this option (Classless Static Routes)
 150         # MUST NOT install the routes specified in the Static Routes
 151         # option (option code 33) if both a Static Routes option and the
 152         # Classless Static Routes option are provided.
 153
 154         if [ -n "$new_classless_routes" ]; then
 155                 fill_classless_routes "$new_classless_routes"
 156                 $LOGGER "New Classless Static Routes ($interface): $classless_routes"
 157                 set $classless_routes
 158                 while [ $# -gt 1 ]; do
 159                         if [ "0.0.0.0" = "$2" ]; then
 160                                 route add "$1" -iface "$interface"
 161                         else
 162                                 route add "$1" "$2"
 163                         fi
 164                         shift; shift
 165                 done
 166                 return
 167         fi
 168
 169         for router in $new_routers; do
 170                 if is_default_interface; then
 171
 172                         if [ "$new_ip_address" = "$router" ]; then
 173                                 route add default -iface $router >/dev/null 2>&1
 174                         else
 175                                 if [ "$new_subnet_mask" = "255.255.255.255" ]; then
 176                                         route add "$router" -iface "$interface" >/dev/null 2>&1
 177                                 fi
 178
 179                                 route add default $router >/dev/null 2>&1
 180                         fi
 181                 fi
 182                 # 2nd and subsequent default routers error out, so explicitly
 183                 # stop processing the list after the first one.
 184                 break
 185         done
 186
 187         if [ -n "$new_static_routes" ]; then
 188                 $LOGGER "New Static Routes ($interface): $new_static_routes"
 189                 set $new_static_routes
 190                 while [ $# -gt 1 ]; do
 191                         route add $1 $2
 192                         shift; shift
 193                 done
 194         fi
 195 }
 196
 197 add_new_resolv_conf() {
 198         # XXX Old code did not create/update resolv.conf unless both
 199         # $new_domain_name and $new_domain_name_servers were provided.  PR
 200         # #3135 reported some ISP's only provide $new_domain_name_servers and
 201         # thus broke the script. This code creates the resolv.conf if either
 202         # are provided.
 203
 204         local tmpres=/var/run/resolv.conf.${interface}
 205         rm -f $tmpres
 206
 207         if [ -n "$new_domain_search" ]; then
 208                 echo "search $new_domain_search" >>$tmpres
 209         elif [ -n "$new_domain_name" ]; then
 210                 echo "search $new_domain_name" >>$tmpres
 211         fi
 212
 213         if [ -n "$new_domain_name_servers" ]; then
 214                 for nameserver in $new_domain_name_servers; do
 215                         echo "nameserver $nameserver" >>$tmpres
 216                 done
 217         fi
 218
 219         if [ -f $tmpres ]; then
 220                 if [ -f /etc/resolv.conf.tail ]; then
 221                         cat /etc/resolv.conf.tail >>$tmpres
 222                 fi
 223
 224                 case $resolvconf_enable in
 225                 # "no", "false", "off", or "0"
 226                 [Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
 227                         # When resolv.conf is not changed actually, we don't
 228                         # need to update it.
 229                         # If /usr is not mounted yet, we cannot use cmp, then
 230                         # the following test fails.  In such case, we simply
 231                         # ignore an error and do update resolv.conf.
 232                         if cmp -s $tmpres /etc/resolv.conf; then
 233                                 rm -f $tmpres
 234                                 return 0
 235                         fi 2>/dev/null
 236
 237                         # In case (e.g. during OpenBSD installs)
 238                         # /etc/resolv.conf is a symbolic link, take
 239                         # care to preserve the link and write the new
 240                         # data in the correct location.
 241
 242                         if [ -f /etc/resolv.conf ]; then
 243                                 cat /etc/resolv.conf > /etc/resolv.conf.save
 244                         fi
 245                         cat $tmpres > /etc/resolv.conf
 246
 247                         # Try to ensure correct ownership and permissions.
 248                         chown -RL root:wheel /etc/resolv.conf
 249                         chmod -RL 644 /etc/resolv.conf
 250                         ;;
 251
 252                 *)
 253                         /sbin/resolvconf -a ${interface} < $tmpres
 254                         ;;
 255                 esac
 256
 257                 rm -f $tmpres
 258
 259                 return 0
 260         fi
 261
 262         return 1
 263 }
 264
 265 # Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
 266 exit_with_hooks() {
 267         exit_status=$1
 268         if [ -f /etc/dhclient-exit-hooks ]; then
 269                 . /etc/dhclient-exit-hooks
 270         fi
 271         # probably should do something with exit status of the local script
 272         exit $exit_status
 273 }
 274
 275 # Get the interface with the current ipv4 default route on it using only
 276 # commands that are available prior to /usr being mounted.
 277 is_default_interface()
 278 {
 279         routeget="`route -n get -inet default`"
 280         oldifs="$IFS"
 281         IFS="
 282 "
 283         defif=
 284         for line in $routeget ; do
 285                 case $line in
 286                 *interface:*)
 287                         defif=${line##*: }
 288                         ;;
 289                 esac
 290         done
 291         IFS=${oldifs}
 292
 293         if [ -z "$defif" -o "$defif" = "$interface" ]; then
 294                 return 0
 295         else
 296                 return 1
 297         fi
 298 }
 299
 300 #
 301 # Start of active code.
 302 #
 303
 304 # Invoke the local dhcp client enter hooks, if they exist.
 305 if [ -f /etc/dhclient-enter-hooks ]; then
 306         exit_status=0
 307         . /etc/dhclient-enter-hooks
 308         # allow the local script to abort processing of this state
 309         # local script must set exit_status variable to nonzero.
 310         if [ $exit_status -ne 0 ]; then
 311                 exit $exit_status
 312         fi
 313 fi
 314
 315 : ${resolvconf_enable="YES"}
 316
 317 case $reason in
 318 MEDIUM)
 319         eval "$IFCONFIG $interface $medium"
 320         sleep 1
 321         ;;
 322
 323 PREINIT)
 324         delete_old_alias
 325         eval "$IFCONFIG $interface up"
 326         ;;
 327
 328 ARPCHECK|ARPSEND)
 329         ;;
 330
 331 BOUND|RENEW|REBIND|REBOOT)
 332         check_hostname
 333         if [ -n "$old_ip_address" ]; then
 334                 if [ "$old_ip_address" != "$alias_ip_address" ]; then
 335                         delete_old_alias
 336                 fi
 337                 if [ "$old_ip_address" != "$new_ip_address" ]; then
 338                         delete_old_address
 339                         delete_old_routes
 340                 fi
 341         fi
 342         if [ "$reason" = BOUND ] || \
 343            [ "$reason" = REBOOT ] || \
 344            [ -z "$old_ip_address" ] || \
 345            [ "$old_ip_address" != "$new_ip_address" ]; then
 346                 add_new_address
 347                 add_new_routes
 348         fi
 349         if [ "$new_ip_address" != "$alias_ip_address" ]; then
 350                 add_new_alias
 351         fi
 352         if is_default_interface; then
 353                 add_new_resolv_conf
 354         fi
 355         ;;
 356
 357 EXPIRE|FAIL)
 358         delete_old_alias
 359         if [ -n "$old_ip_address" ]; then
 360                 delete_old_address
 361                 delete_old_routes
 362         fi
 363         if [ -x $ARP ]; then
 364                 $ARP -d -a -i $interface
 365         fi
 366         # XXX Why add alias we just deleted above?
 367         add_new_alias
 368         if is_default_interface; then
 369                 case $resolvconf_enable in
 370                 # "no", "false", "off", or "0"
 371                 [Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
 372                         if [ -f /etc/resolv.conf.save ]; then
 373                                 cat /etc/resolv.conf.save > /etc/resolv.conf
 374                         fi
 375                         ;;
 376                 *)
 377                         /sbin/resolvconf -d ${interface}
 378                         ;;
 379                 esac
 380         fi
 381         ;;
 382
 383 TIMEOUT)
 384         delete_old_alias
 385         add_new_address
 386         sleep 1
 387         if [ -n "$new_routers" ]; then
 388                 $LOGGER "New Routers ($interface): $new_routers"
 389                 set "$new_routers"
 390                 if ping -q -c 1 -t 1 "$1"; then
 391                         if [ "$new_ip_address" != "$alias_ip_address" ]; then
 392                                 add_new_alias
 393                         fi
 394                         add_new_routes
 395                         if ! is_default_interface; then
 396                                 exit_with_hooks 0
 397                         fi
 398                         if add_new_resolv_conf; then
 399                                 exit_with_hooks 0
 400                         fi
 401                 fi
 402         fi
 403         eval "$IFCONFIG $interface inet -alias $new_ip_address $medium"
 404         delete_old_routes
 405         exit_with_hooks 1
 406         ;;
 407 esac
 408
 409 exit_with_hooks 0