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_servers" != x ]; then
  27     cat /dev/null > /etc/resolv.conf.dhclient
  28     chmod 644 /etc/resolv.conf.dhclient
  29     if [ x"$new_domain_search" != x ]; then
  30       echo search $new_domain_search >> /etc/resolv.conf.dhclient
  31     elif [ x"$new_domain_name" != x ]; then
  32       # Note that the DHCP 'Domain Name Option' is really just a domain
  33       # name, and that this practice of using the domain name option as
  34       # a search path is both nonstandard and deprecated.
  35       echo search $new_domain_name >> /etc/resolv.conf.dhclient
  36     fi
  37     for nameserver in $new_domain_name_servers; do
  38       echo nameserver $nameserver >>/etc/resolv.conf.dhclient
  39     done
  40
  41     mv /etc/resolv.conf.dhclient /etc/resolv.conf
  42   fi
  43 }
  44
  45 # Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
  46 exit_with_hooks() {
  47   exit_status=$1
  48   if [ -f /etc/dhclient-exit-hooks ]; then
  49     . /etc/dhclient-exit-hooks
  50   fi
  51 # probably should do something with exit status of the local script
  52   exit $exit_status
  53 }
  54
  55 # Invoke the local dhcp client enter hooks, if they exist.
  56 if [ -f /etc/dhclient-enter-hooks ]; then
  57   exit_status=0
  58   . /etc/dhclient-enter-hooks
  59   # allow the local script to abort processing of this state
  60   # local script must set exit_status variable to nonzero.
  61   if [ $exit_status -ne 0 ]; then
  62     exit $exit_status
  63   fi
  64 fi
  65
  66 release=`uname -r`
  67 release=`expr $release : '\(.*\)\..*'`
  68 relminor=`echo $release |sed -e 's/[0-9]*\.\([0-9][0-9]*\)\(\..*\)*$/\1/'`
  69 relmajor=`echo $release |sed -e 's/\([0-9][0-9]*\)\..*$/\1/'`
  70
  71 if [ x$new_broadcast_address != x ]; then
  72   new_broadcast_arg="broadcast $new_broadcast_address"
  73 fi
  74 if [ x$old_broadcast_address != x ]; then
  75   old_broadcast_arg="broadcast $old_broadcast_address"
  76 fi
  77 if [ x$new_subnet_mask != x ]; then
  78   new_subnet_arg="netmask $new_subnet_mask"
  79 fi
  80 if [ x$old_subnet_mask != x ]; then
  81   old_subnet_arg="netmask $old_subnet_mask"
  82 fi
  83 if [ x$alias_subnet_mask != x ]; then
  84   alias_subnet_arg="netmask $alias_subnet_mask"
  85 fi
  86
  87 if [ x$reason = xMEDIUM ]; then
  88   # Linux doesn't do mediums (ok, ok, media).
  89   exit_with_hooks 0
  90 fi
  91
  92 if [ x$reason = xPREINIT ]; then
  93   if [ x$alias_ip_address != x ]; then
  94     # Bring down alias interface. Its routes will disappear too.
  95     ifconfig $interface:0- inet 0
  96   fi
  97   if [ $relmajor -lt 2 ] || ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] )
  98    then
  99     ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 \
 100                 broadcast 255.255.255.255 up
 101     # Add route to make broadcast work. Do not omit netmask.
 102     route add default dev $interface netmask 0.0.0.0
 103   else
 104     ifconfig $interface 0 up
 105   fi
 106
 107   # We need to give the kernel some time to get the interface up.
 108   sleep 1
 109
 110   exit_with_hooks 0
 111 fi
 112
 113 if [ x$reason = xARPCHECK ] || [ x$reason = xARPSEND ]; then
 114   exit_with_hooks 0
 115 fi
 116
 117 if [ x$reason = xBOUND ] || [ x$reason = xRENEW ] || \
 118    [ x$reason = xREBIND ] || [ x$reason = xREBOOT ]; then
 119   current_hostname=`hostname`
 120   if [ x$current_hostname = x ] || \
 121      [ x$current_hostname = x$old_host_name ]; then
 122     if [ x$current_hostname = x ] || \
 123        [ x$new_host_name != x$old_host_name ]; then
 124       hostname $new_host_name
 125     fi
 126   fi
 127
 128   if [ x$old_ip_address != x ] && [ x$alias_ip_address != x ] && \
 129                 [ x$alias_ip_address != x$old_ip_address ]; then
 130     # Possible new alias. Remove old alias.
 131     ifconfig $interface:0- inet 0
 132   fi
 133   if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]; then
 134     # IP address changed. Bringing down the interface will delete all routes,
 135     # and clear the ARP cache.
 136     ifconfig $interface inet 0 down
 137
 138   fi
 139   if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \
 140      [ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then
 141
 142     ifconfig $interface inet $new_ip_address $new_subnet_arg \
 143                                                         $new_broadcast_arg
 144     # Add a network route to the computed network address.
 145     if [ $relmajor -lt 2 ] || \
 146                 ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] ); then
 147       route add -net $new_network_number $new_subnet_arg dev $interface
 148     fi
 149     for router in $new_routers; do
 150       route add default gw $router
 151     done
 152   fi
 153   if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];
 154    then
 155     ifconfig $interface:0- inet 0
 156     ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 157     route add -host $alias_ip_address $interface:0
 158   fi
 159   make_resolv_conf
 160   exit_with_hooks 0
 161 fi
 162
 163 if [ x$reason = xEXPIRE ] || [ x$reason = xFAIL ] || [ x$reason = xRELEASE ] \
 164    || [ x$reason = xSTOP ]; then
 165   if [ x$alias_ip_address != x ]; then
 166     # Turn off alias interface.
 167     ifconfig $interface:0- inet 0
 168   fi
 169   if [ x$old_ip_address != x ]; then
 170     # Shut down interface, which will delete routes and clear arp cache.
 171     ifconfig $interface inet 0 down
 172   fi
 173   if [ x$alias_ip_address != x ]; then
 174     ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 175     route add -host $alias_ip_address $interface:0
 176   fi
 177   exit_with_hooks 0
 178 fi
 179
 180 if [ x$reason = xTIMEOUT ]; then
 181   if [ x$alias_ip_address != x ]; then
 182     ifconfig $interface:0- inet 0
 183   fi
 184   ifconfig $interface inet $new_ip_address $new_subnet_arg \
 185                                         $new_broadcast_arg
 186   set $new_routers
 187   ############## what is -w in ping?
 188   if ping -q -c 1 $1; then
 189     if [ x$new_ip_address != x$alias_ip_address ] && \
 190                         [ x$alias_ip_address != x ]; then
 191       ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
 192       route add -host $alias_ip_address dev $interface:0
 193     fi
 194     if [ $relmajor -lt 2 ] || \
 195                 ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] ); then
 196       route add -net $new_network_number
 197     fi
 198     for router in $new_routers; do
 199       route add default gw $router
 200     done
 201     make_resolv_conf
 202     exit_with_hooks 0
 203   fi
 204   ifconfig $interface inet 0 down
 205   exit_with_hooks 1
 206 fi
 207
 208 exit_with_hooks 0