client/scripts/linux

   1 #!/bin/bash
   2 # dhclient-script for Linux. Dan Halbert, March, 1997.
   3 # Updated for Linux 2.[12] by Brian J. Murrell, January 1999.
   4 # No guarantees about this. I'm a novice at the details of Linux
   5 # networking.
   6
   7 # Notes:
   8
   9 # 0. This script is based on the netbsd script supplied with dhcp-970306.
  10
  11 # 1. ifconfig down apparently deletes all relevant routes and flushes
  12 # the arp cache, so this doesn't need to be done explicitly.
  13
  14 # 2. The alias address handling here has not been tested AT ALL.
  15 # I'm just going by the doc of modern Linux ip aliasing, which uses
  16 # notations like eth0:0, eth0:1, for each alias.
  17
  18 # 3. I have to calculate the network address, and calculate the broadcast
  19 # address if it is not supplied. This might be much more easily done
  20 # by the dhclient C code, and passed on.
  21
  22 # 4. TIMEOUT not tested. ping has a flag I don't know, and I'm suspicious
  23 # of the $1 in its args.
  24
  25 # 'ip' just looks too weird.  /sbin/ip looks less weird.
  26 ip=/sbin/ip
  27
  28 make_resolv_conf() {
  29   if [ x"$new_domain_name_servers" != x ]; then
  30     cat /dev/null > /etc/resolv.conf.dhclient
  31     chmod 644 /etc/resolv.conf.dhclient
  32     if [ x"$new_domain_search" != x ]; then
  33       echo search $new_domain_search >> /etc/resolv.conf.dhclient
  34     elif [ x"$new_domain_name" != x ]; then
  35       # Note that the DHCP 'Domain Name Option' is really just a domain
  36       # name, and that this practice of using the domain name option as
  37       # a search path is both nonstandard and deprecated.
  38       echo search $new_domain_name >> /etc/resolv.conf.dhclient
  39     fi
  40     for nameserver in $new_domain_name_servers; do
  41       echo nameserver $nameserver >>/etc/resolv.conf.dhclient
  42     done
  43
  44     mv /etc/resolv.conf.dhclient /etc/resolv.conf
  45   elif [ "x${new_dhcp6_name_servers}" != x ] ; then
  46     cat /dev/null > /etc/resolv.conf.dhclient6
  47     chmod 644 /etc/resolv.conf.dhclient6
  48
  49     if [ "x${new_dhcp6_domain_search}" != x ] ; then
  50       echo search ${new_dhcp6_domain_search} >> /etc/resolv.conf.dhclient6
  51     fi
  52     shopt -s nocasematch
  53     for nameserver in ${new_dhcp6_name_servers} ; do
  54       # If the nameserver has a link-local address
  55       # add a <zone_id> (interface name) to it.
  56       if  [[ "$nameserver" =~ ^fe80:: ]]
  57       then
  58         zone_id="%$interface"
  59       else
  60         zone_id=
  61       fi
  62       echo nameserver ${nameserver}$zone_id >> /etc/resolv.conf.dhclient6
  63     done
  64     shopt -u nocasematch
  65
  66     mv /etc/resolv.conf.dhclient6 /etc/resolv.conf
  67   fi
  68 }
  69
  70 # Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
  71 exit_with_hooks() {
  72   exit_status=$1
  73   if [ -f /etc/dhclient-exit-hooks ]; then
  74     . /etc/dhclient-exit-hooks
  75   fi
  76 # probably should do something with exit status of the local script
  77   exit $exit_status
  78 }
  79
  80 # Invoke the local dhcp client enter hooks, if they exist.
  81 if [ -f /etc/dhclient-enter-hooks ]; then
  82   exit_status=0
  83   . /etc/dhclient-enter-hooks
  84   # allow the local script to abort processing of this state
  85   # local script must set exit_status variable to nonzero.
  86   if [ $exit_status -ne 0 ]; then
  87     exit $exit_status
  88   fi
  89 fi
  90
  91 ###
  92 ### DHCPv4 Handlers
  93 ###
  94
  95 if [ x$new_broadcast_address != x ]; then
  96   new_broadcast_arg="broadcast $new_broadcast_address"
  97 fi
  98 if [ x$old_broadcast_address != x ]; then
  99   old_broadcast_arg="broadcast $old_broadcast_address"
 100 fi
 101 if [ x$new_subnet_mask != x ]; then
 102   new_subnet_arg="netmask $new_subnet_mask"
 103 fi
 104 if [ x$old_subnet_mask != x ]; then
 105   old_subnet_arg="netmask $old_subnet_mask"
 106 fi
 107 if [ x$alias_subnet_mask != x ]; then
 108   alias_subnet_arg="netmask $alias_subnet_mask"
 109 fi
 110 if [ x$new_interface_mtu != x ]; then
 111   mtu_arg="mtu $new_interface_mtu"
 112 fi
 113 if [ x$IF_METRIC != x ]; then
 114   metric_arg="metric $IF_METRIC"
 115 fi
 116
 117 if [ x$reason = xMEDIUM ]; then
 118   # Linux doesn't do mediums (ok, ok, media).
 119   exit_with_hooks 0
 120 fi
 121
 122 if [ x$reason = xPREINIT ]; then
 123   if [ x$alias_ip_address != x ]; then
 124     # Bring down alias interface. Its routes will disappear too.
 125     ifconfig $interface:0- inet 0
 126   fi
 127   ifconfig $interface 0 up
 128
 129   # We need to give the kernel some time to get the interface up.
 130   sleep 1
 131
 132   exit_with_hooks 0
 133 fi
 134
 135 if [ x$reason = xARPCHECK ] || [ x$reason = xARPSEND ]; then
 136   exit_with_hooks 0
 137 fi
 138
 139 if [ x$reason = xBOUND ] || [ x$reason = xRENEW ] || \
 140    [ x$reason = xREBIND ] || [ x$reason = xREBOOT ]; then
 141   current_hostname=`hostname`
 142   if [ x$current_hostname = x ] || \
 143      [ x$current_hostname = "x(none)" ] || \
 144      [ x$current_hostname = xlocalhost ] || \
 145      [ x$current_hostname = x$old_host_name ]; then
 146     if [ x$new_host_name != x$old_host_name ]; then
 147       hostname "$new_host_name"
 148     fi
 149   fi
 150
 151   if [ x$old_ip_address != x ] && [ x$alias_ip_address != x ] && \
 152                 [ x$alias_ip_address != x$old_ip_address ]; then
 153     # Possible new alias. Remove old alias.
 154     ifconfig $interface:0- inet 0
 155   fi
 156   if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]; then
 157     # IP address changed. Bringing down the interface will delete all routes,
 158     # and clear the ARP cache.
 159     ifconfig $interface inet 0 down
 160
 161   fi
 162   if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \
 163      [ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then
 164
 165     ifconfig $interface inet $new_ip_address $new_subnet_arg \
 166                                         $new_broadcast_arg $mtu_arg
 167     # Add a network route to the computed network address.
 168     for router in $new_routers; do
 169       if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
 170         route add -host $router dev $interface
 171       fi
 172       route add default gw $router $metric_arg dev $interface
 173     done
 174   else
 175     # we haven't changed the address, have we changed other options
 176     # that we wish to update?
 177     if [ x$new_routers != x ] && [ x$new_routers != x$old_routers ] ; then
 178       # if we've changed routers delete the old and add the new.
 179       for router in $old_routers; do
 180         route del default gw $router
 181       done
 182       for router in $new_routers; do
 183         if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
 184           route add -host $router dev $interface
 185         fi
 186         route add default gw $router $metric_arg dev $interface
 187       done
 188     fi
 189   fi
 190   if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];
 191    then
 192     ifconfig $interface:0- inet 0
 193     ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 194     route add -host $alias_ip_address $interface:0
 195   fi
 196   make_resolv_conf
 197   exit_with_hooks 0
 198 fi
 199
 200 if [ x$reason = xEXPIRE ] || [ x$reason = xFAIL ] || [ x$reason = xRELEASE ] \
 201    || [ x$reason = xSTOP ]; then
 202   if [ x$alias_ip_address != x ]; then
 203     # Turn off alias interface.
 204     ifconfig $interface:0- inet 0
 205   fi
 206   if [ x$old_ip_address != x ]; then
 207     # Shut down interface, which will delete routes and clear arp cache.
 208     ifconfig $interface inet 0 down
 209   fi
 210   if [ x$alias_ip_address != x ]; then
 211     ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 212     route add -host $alias_ip_address $interface:0
 213   fi
 214   exit_with_hooks 0
 215 fi
 216
 217 if [ x$reason = xTIMEOUT ]; then
 218   if [ x$alias_ip_address != x ]; then
 219     ifconfig $interface:0- inet 0
 220   fi
 221   ifconfig $interface inet $new_ip_address $new_subnet_arg \
 222                                         $new_broadcast_arg $mtu_arg
 223   set $new_routers
 224   if ping -q -c 1 $1; then
 225     if [ x$new_ip_address != x$alias_ip_address ] && \
 226                         [ x$alias_ip_address != x ]; then
 227       ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 228       route add -host $alias_ip_address dev $interface:0
 229     fi
 230     for router in $new_routers; do
 231       if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
 232         route add -host $router dev $interface
 233       fi
 234       route add default gw $router $metric_arg dev $interface
 235     done
 236     make_resolv_conf
 237     exit_with_hooks 0
 238   fi
 239   ifconfig $interface inet 0 down
 240   exit_with_hooks 1
 241 fi
 242
 243 ###
 244 ### DHCPv6 Handlers
 245 ###
 246
 247 if [ x$reason = xPREINIT6 ] ; then
 248   # Ensure interface is up.
 249   ${ip} link set ${interface} up
 250
 251   # We need to give the kernel some time to active interface
 252   interface_up_wait_time=5
 253   for i in $(seq 0 ${interface_up_wait_time})
 254   do
 255       ifconfig ${interface} | grep RUNNING >/dev/null 2>&1
 256       if [ $? -eq 0 ]; then
 257           break;
 258       fi
 259       sleep 1
 260   done
 261
 262   # Remove any stale addresses from aborted clients.
 263   ${ip} -f inet6 addr flush dev ${interface} scope global permanent
 264
 265   # Wait for duplicate address detection for this interface if the
 266   # --dad-wait-time parameter has been specified and is greater than
 267   # zero.
 268   if [ ${dad_wait_time} -gt 0 ]; then
 269       # Check if any IPv6 address on this interface is marked as
 270       # tentative.
 271       ${ip} addr show ${interface} | grep inet6 | grep tentative \
 272           &> /dev/null
 273       if [ $? -eq 0 ]; then
 274           # Wait for duplicate address detection to complete or for
 275           # the timeout specified as --dad-wait-time.
 276           for i in $(seq 0 $dad_wait_time)
 277           do
 278               # We're going to poll for the tentative flag every second.
 279               sleep 1
 280               ${ip} addr show ${interface} | grep inet6 | grep tentative \
 281                   &> /dev/null
 282               if [ $? -ne 0 ]; then
 283                   break;
 284               fi
 285           done
 286       fi
 287   fi
 288
 289   exit_with_hooks 0
 290 fi
 291
 292 if [ x${old_ip6_prefix} != x ] || [ x${new_ip6_prefix} != x ] ; then
 293     echo Prefix ${reason} old=${old_ip6_prefix} new=${new_ip6_prefix}
 294
 295     exit_with_hooks 0
 296 fi
 297
 298 if [ x$reason = xBOUND6 ] ; then
 299   if [ x${new_ip6_address} = x ] || [ x${new_ip6_prefixlen} = x ] ; then
 300     exit_with_hooks 2;
 301   fi
 302
 303   ${ip} -f inet6 addr add ${new_ip6_address}/${new_ip6_prefixlen} \
 304         dev ${interface} scope global
 305
 306   # Check for nameserver options.
 307   make_resolv_conf
 308
 309   exit_with_hooks 0
 310 fi
 311
 312 if [ x$reason = xRENEW6 ] || [ x$reason = xREBIND6 ] ; then
 313   if [ x${new_ip6_address} != x ] && [ x${new_ip6_prefixlen} != x ] ; then
 314     ${ip} -f inet6 addr add ${new_ip6_address}/${new_ip6_prefixlen} \
 315         dev ${interface} scope global
 316   fi
 317
 318   # Make sure nothing has moved around on us.
 319
 320   # Nameservers/domains/etc.
 321   if [ "x${new_dhcp6_name_servers}" != "x${old_dhcp6_name_servers}" ] ||
 322      [ "x${new_dhcp6_domain_search}" != "x${old_dhcp6_domain_search}" ] ; then
 323     make_resolv_conf
 324   fi
 325
 326   exit_with_hooks 0
 327 fi
 328
 329 if [ x$reason = xDEPREF6 ] ; then
 330   if [ x${new_ip6_prefixlen} = x ] ; then
 331     exit_with_hooks 2;
 332   fi
 333
 334   ${ip} -f inet6 addr change ${new_ip6_address}/${new_ip6_prefixlen} \
 335        dev ${interface} scope global preferred_lft 0
 336
 337   exit_with_hooks 0
 338 fi
 339
 340 if [ x$reason = xEXPIRE6 -o x$reason = xRELEASE6 -o x$reason = xSTOP6 ] ; then
 341   if [ x${old_ip6_address} = x ] || [ x${old_ip6_prefixlen} = x ] ; then
 342     exit_with_hooks 2;
 343   fi
 344
 345   ${ip} -f inet6 addr del ${old_ip6_address}/${old_ip6_prefixlen} \
 346         dev ${interface}
 347
 348   exit_with_hooks 0
 349 fi
 350
 351 exit_with_hooks 0