openvpn/contrib/pull-resolv-conf/client.up

   1 #!/bin/bash
   2
   3 # Copyright (c) 2005 by OpenVPN Solutions LLC
   4 # Licensed under the GPL version 2
   5
   6 # First version by Jesse Adelman
   7 # someone at boldandbusted dink com
   8 # http://www.boldandbusted.com/
   9
  10 # PURPOSE: This script automatically sets the proper /etc/resolv.conf entries
  11 # as pulled down from an OpenVPN server.
  12
  13 # INSTALL NOTES:
  14 # Place this in /etc/openvpn/client.up
  15 # Then, add the following to your /etc/openvpn/<clientconfig>.conf:
  16 #   client
  17 #   pull dhcp-options
  18 #   up /etc/openvpn/client.up
  19 # Next, "chmod a+x /etc/openvpn/client.up"
  20
  21 # USAGE NOTES:
  22 # Note that this script is best served with the companion "client.down"
  23 # script.
  24
  25 # Only tested on Gentoo Linux 2005.0 with OpenVPN 2.0
  26 # It should work with any GNU/Linux with /etc/resolv.conf
  27
  28 # This runs with the context of the OpenVPN UID/GID
  29 # at the time of execution. This generally means that
  30 # the client "up" script will run fine, but the "down" script
  31 # will require the use of the OpenVPN "down-root" plugin
  32 # which is in the plugins/ directory of the OpenVPN source tree
  33
  34 # A horrid work around, from a security perspective,
  35 # is to run OpenVPN as root. THIS IS NOT RECOMMENDED. You have
  36 # been WARNED.
  37
  38 # init variables
  39
  40 i=1
  41 j=1
  42 unset fopt
  43 unset dns
  44 unset opt
  45
  46 # Convert ENVs to an array
  47
  48 while fopt=foreign_option_$i; [ -n "${!fopt}" ]; do
  49 {
  50         opt[i-1]=${!fopt}
  51         case ${opt[i-1]} in
  52                 *DOMAIN* ) domain=`echo ${opt[i-1]} | \
  53                                 sed -e 's/dhcp-option DOMAIN //g'` ;;
  54                 *DNS*    ) dns[j-1]=`echo ${opt[i-1]} | \
  55                                 sed -e 's/dhcp-option DNS //g'`
  56                                let j++ ;;
  57         esac
  58         let i++
  59 }
  60 done
  61
  62 # Now, do the work
  63
  64 if [ -n "${dns[*]}" ]; then
  65         for i in "${dns[@]}"; do
  66                 sed -i -e "1,1 i nameserver ${i}" /etc/resolv.conf || die
  67         done
  68 fi
  69
  70 if [ -n "${domain}" ]; then
  71         sed -i -e "$j,1 i search ${domain}" /etc/resolv.conf || die
  72 fi
  73
  74 # all done...
  75 exit 0