examples/udhcp/simple.script

   1 #!/bin/sh
   2 # udhcpc script edited by Tim Riker <Tim@Rikers.org>
   3
   4 RESOLV_CONF="/etc/resolv.conf"
   5
   6 [ -n "$1" ] || { echo "Error: should be called from udhcpc"; exit 1; }
   7
   8 NETMASK=""
   9 if command -v ip >/dev/null; then
  10         [ -n "$subnet" ] && NETMASK="/$subnet"
  11 else
  12         [ -n "$subnet" ] && NETMASK="netmask $subnet"
  13 fi
  14 BROADCAST="broadcast +"
  15 [ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"
  16
  17 case "$1" in
  18         deconfig)
  19                 echo "Clearing IP addresses on $interface, upping it"
  20                 if command -v ip >/dev/null; then
  21                         ip -4 addr flush dev $interface
  22                         ip link set dev $interface up
  23                 else
  24                         ifconfig $interface 0.0.0.0
  25                 fi
  26                 ;;
  27
  28         renew|bound)
  29                 echo "Setting IP address $ip on $interface"
  30                 if command -v ip >/dev/null; then
  31                         ip addr add $ip$NETMASK $BROADCAST dev $interface
  32                 else
  33                         ifconfig $interface $ip $NETMASK $BROADCAST
  34                 fi
  35
  36                 if [ -n "$router" ] ; then
  37                         echo "Deleting routers"
  38                         while route del default gw 0.0.0.0 dev $interface ; do
  39                                 :
  40                         done
  41
  42                         metric=0
  43                         for i in $router ; do
  44                                 echo "Adding router $i"
  45                                 if [ "$subnet" = "255.255.255.255" ]; then
  46         # special case for /32 subnets:
  47         # /32 instructs kernel to always use routing for all outgoing packets
  48         # (they can never be sent to local subnet - there is no local subnet for /32).
  49         # Used in datacenters, avoids the need for private ip-addresses between two hops.
  50                                         ip route add $i dev $interface
  51                                 fi
  52                                 route add default gw $i dev $interface metric $((metric++))
  53                         done
  54                 fi
  55
  56                 # If the file is a symlink somewhere (like /etc/resolv.conf
  57                 # pointing to /run/resolv.conf), make sure things work.
  58                 if test -L "$RESOLV_CONF"; then
  59                         # If it's a dangling symlink, try to create the target.
  60                         test -e "$RESOLV_CONF" || touch "$RESOLV_CONF"
  61                 fi
  62                 realconf=$(readlink -f "$RESOLV_CONF" 2>/dev/null || echo "$RESOLV_CONF")
  63                 echo "Recreating $realconf"
  64                 tmpfile="$realconf-$$"
  65                 > "$tmpfile"
  66                 [ -n "$domain" ] && echo "search $domain" >> "$tmpfile"
  67                 for i in $dns ; do
  68                         echo " Adding DNS server $i"
  69                         echo "nameserver $i" >> "$tmpfile"
  70                 done
  71                 mv "$tmpfile" "$realconf"
  72                 ;;
  73 esac
  74
  75 exit 0