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 AWK=/usr/bin/awk
  24 HOSTNAME=/bin/hostname
  25 IFCONFIG='/sbin/ifconfig -n'
  26 NETSTAT=/usr/bin/netstat
  27
  28 LOCALHOST=127.0.0.1
  29
  30 if [ -x /usr/bin/logger ]; then
  31         LOGGER="/usr/bin/logger -s -p user.notice -t dhclient"
  32 else
  33         LOGGER=echo
  34 fi
  35
  36 #
  37 # Helper functions that implement common actions.
  38 #
  39
  40 check_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
  52 arp_flush() {
  53         arp -an -i $interface | \
  54                 sed -n -e 's/^.*(\(.*\)) at .*$/arp -d \1/p' | \
  55                 sh >/dev/null 2>&1
  56 }
  57
  58 delete_old_address() {
  59         eval "$IFCONFIG $interface inet -alias $old_ip_address $medium"
  60 }
  61
  62 add_new_address() {
  63         eval "$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): $new_routers"
  73 }
  74
  75 delete_old_alias() {
  76         if [ -n "$alias_ip_address" ]; then
  77                 $IFCONFIG $interface inet -alias $alias_ip_address > /dev/null 2>&1
  78                 #route delete $alias_ip_address $LOCALHOST > /dev/null 2>&1
  79         fi
  80 }
  81
  82 add_new_alias() {
  83         if [ -n "$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
  90 fill_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 $router"
 111                 shift; shift; shift; shift
 112         done
 113 }
 114
 115 delete_old_routes() {
 116         #route delete "$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
 144 add_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
 192 add_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.
 248 exit_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.
 262 if [ -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
 270 fi
 271
 272 if [ -x $NETSTAT ]; then
 273         if_defaultroute=`$NETSTAT -rnf inet | $AWK '{if ($1=="default") printf $6}'`
 274 else
 275         if_defaultroute="x"
 276 fi
 277
 278 case $reason in
 279 MEDIUM)
 280         eval "$IFCONFIG $interface $medium"
 281         eval "$IFCONFIG $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1
 282         sleep 1
 283         ;;
 284
 285 PREINIT)
 286         delete_old_alias
 287         $IFCONFIG $interface inet alias 0.0.0.0 netmask 0.0.0.0 broadcast 255.255.255.255 up
 288         ;;
 289
 290 ARPCHECK|ARPSEND)
 291         ;;
 292
 293 BOUND|RENEW|REBIND|REBOOT)
 294         check_hostname
 295         if [ -n "$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" != "$alias_ip_address" ]; then
 312                 add_new_alias
 313         fi
 314         add_new_resolv_conf
 315         ;;
 316
 317 EXPIRE|FAIL)
 318         delete_old_alias
 319         if [ -n "$old_ip_address" ]; then
 320                 delete_old_address
 321                 delete_old_routes
 322         fi
 323         if [ -x $ARP ]; then
 324                 $ARP -d -a -i $interface
 325         fi
 326         # XXX Why add alias we just deleted above?
 327         add_new_alias
 328         if [ -f /etc/resolv.conf.save ]; then
 329                 cat /etc/resolv.conf.save > /etc/resolv.conf
 330         fi
 331         ;;
 332
 333 TIMEOUT)
 334         delete_old_alias
 335         add_new_address
 336         sleep 1
 337         if [ -n "$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         ;;
 354 esac
 355
 356 exit_with_hooks 0