dist/dhcp/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 $1 in its args.
  24
  25 make_resolv_conf() {
  26   if [ "x$new_domain_name" != x ] && [ x"$new_domain_name_servers" != x ]; then
  27     echo search $new_domain_name >/etc/resolv.conf
  28     chmod 644 /etc/resolv.conf
  29     for nameserver in $new_domain_name_servers; do
  30       echo nameserver $nameserver >>/etc/resolv.conf
  31     done
  32   fi
  33 }
  34
  35 # Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
  36 exit_with_hooks() {
  37   exit_status=$1
  38   if [ -f /etc/dhclient-exit-hooks ]; then
  39     . /etc/dhclient-exit-hooks
  40   fi
  41 # probably should do something with exit status of the local script
  42   exit $exit_status
  43 }
  44
  45 # Invoke the local dhcp client enter hooks, if they exist.
  46 if [ -f /etc/dhclient-enter-hooks ]; then
  47   exit_status=0
  48   . /etc/dhclient-enter-hooks
  49   # allow the local script to abort processing of this state
  50   # local script must set exit_status variable to nonzero.
  51   if [ $exit_status -ne 0 ]; then
  52     exit $exit_status
  53   fi
  54 fi
  55
  56 release=`uname -r`
  57 release=`expr $release : '\(.*\)\..*'`
  58 relminor=`echo $release |sed -e 's/[0-9]*\.\([0-9][0-9]*\)\(\..*\)*$/\1/'`
  59 relmajor=`echo $release |sed -e 's/\([0-9][0-9]*\)\..*$/\1/'`
  60
  61 if [ x$new_broadcast_address != x ]; then
  62   new_broadcast_arg="broadcast $new_broadcast_address"
  63 fi
  64 if [ x$old_broadcast_address != x ]; then
  65   old_broadcast_arg="broadcast $old_broadcast_address"
  66 fi
  67 if [ x$new_subnet_mask != x ]; then
  68   new_subnet_arg="netmask $new_subnet_mask"
  69 fi
  70 if [ x$old_subnet_mask != x ]; then
  71   old_subnet_arg="netmask $old_subnet_mask"
  72 fi
  73 if [ x$alias_subnet_mask != x ]; then
  74   alias_subnet_arg="netmask $alias_subnet_mask"
  75 fi
  76
  77 if [ x$reason = xMEDIUM ]; then
  78   # Linux doesn't do mediums (ok, ok, media).
  79   exit_with_hooks 0
  80 fi
  81
  82 if [ x$reason = xPREINIT ]; then
  83   if [ x$alias_ip_address != x ]; then
  84     # Bring down alias interface. Its routes will disappear too.
  85     ifconfig $interface:0- inet 0
  86   fi
  87   if [ $relmajor -lt 2 ] || ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] )
  88    then
  89     ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 \
  90                 broadcast 255.255.255.255 up
  91     # Add route to make broadcast work. Do not omit netmask.
  92     route add default dev $interface netmask 0.0.0.0
  93   else
  94     ifconfig $interface 0 up
  95   fi
  96
  97   # We need to give the kernel some time to get the interface up.
  98   sleep 1
  99
 100   exit_with_hooks 0
 101 fi
 102
 103 if [ x$reason = xARPCHECK ] || [ x$reason = xARPSEND ]; then
 104   exit_with_hooks 0
 105 fi
 106
 107 if [ x$reason = xBOUND ] || [ x$reason = xRENEW ] || \
 108    [ x$reason = xREBIND ] || [ x$reason = xREBOOT ]; then
 109   current_hostname=`hostname`
 110   if [ x$current_hostname = x ] || \
 111      [ x$current_hostname = x$old_host_name ]; then
 112     if [ x$current_hostname = x ] || \
 113        [ x$new_host_name != x$old_host_name ]; then
 114       hostname $new_host_name
 115     fi
 116   fi
 117
 118   if [ x$old_ip_address != x ] && [ x$alias_ip_address != x ] && \
 119                 [ x$alias_ip_address != x$old_ip_address ]; then
 120     # Possible new alias. Remove old alias.
 121     ifconfig $interface:0- inet 0
 122   fi
 123   if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]; then
 124     # IP address changed. Bringing down the interface will delete all routes,
 125     # and clear the ARP cache.
 126     ifconfig $interface inet 0 down
 127
 128   fi
 129   if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \
 130      [ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then
 131
 132     ifconfig $interface inet $new_ip_address $new_subnet_arg \
 133                                                         $new_broadcast_arg
 134     # Add a network route to the computed network address.
 135     if [ $relmajor -lt 2 ] || \
 136                 ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] ); then
 137       route add -net $new_network_number $new_subnet_arg dev $interface
 138     fi
 139     for router in $new_routers; do
 140       route add default gw $router
 141     done
 142   fi
 143   if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];
 144    then
 145     ifconfig $interface:0- inet 0
 146     ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 147     route add -host $alias_ip_address $interface:0
 148   fi
 149   make_resolv_conf
 150   exit_with_hooks 0
 151 fi
 152
 153 if [ x$reason = xEXPIRE ] || [ x$reason = xFAIL ] || [ x$reason = xRELEASE ] \
 154    || [ x$reason = xSTOP ]; then
 155   if [ x$alias_ip_address != x ]; then
 156     # Turn off alias interface.
 157     ifconfig $interface:0- inet 0
 158   fi
 159   if [ x$old_ip_address != x ]; then
 160     # Shut down interface, which will delete routes and clear arp cache.
 161     ifconfig $interface inet 0 down
 162   fi
 163   if [ x$alias_ip_address != x ]; then
 164     ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 165     route add -host $alias_ip_address $interface:0
 166   fi
 167   exit_with_hooks 0
 168 fi
 169
 170 if [ x$reason = xTIMEOUT ]; then
 171   if [ x$alias_ip_address != x ]; then
 172     ifconfig $interface:0- inet 0
 173   fi
 174   ifconfig $interface inet $new_ip_address $new_subnet_arg \
 175                                         $new_broadcast_arg
 176   set $new_routers
 177   ############## what is -w in ping?
 178   if ping -q -c 1 $1; then
 179     if [ x$new_ip_address != x$alias_ip_address ] && \
 180                         [ x$alias_ip_address != x ]; then
 181       ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 182       route add -host $alias_ip_address dev $interface:0
 183     fi
 184     if [ $relmajor -lt 2 ] || \
 185                 ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] ); then
 186       route add -net $new_network_number
 187     fi
 188     for router in $new_routers; do
 189       route add default gw $router
 190     done
 191     make_resolv_conf
 192     exit_with_hooks 0
 193   fi
 194   ifconfig $interface inet 0 down
 195   exit_with_hooks 1
 196 fi
 197
 198 exit_with_hooks 0