add covpn - Wrapper to run OpenVPN with server push filtering, tcp/udp/defgw modes

1 files changed, 85 insertions, 0 deletions

diff --git a/covpn/covpn.sh b/covpn/covpn.sh
new file mode 100755
index 0000000..6139909
--- /dev/null
+++ b/covpn/covpn.sh
@@ -0,0 +1,85 @@
+#!/bin/sh
+
+# covpn - Wrapper to run OpenVPN with server push filtering, tcp/udp/defgw modes
+# 2013 Laurent Ghigonis <laurent@gouloum.fr>
+
+# Works together with correct openvpn-up.sh
+# Uses same config file for UDP and TCP, passing --proto and --remote in command line
+# Change of default gateway and DNS is done in openvpn-up.sh
+# Passes env var 'openvpn_gateway' to openvpn-up.sh in case default gw is set to VPN
+# Passes env var 'covpn_conf' to openvpn-up.sh to load it's configuration
+
+usage_exit() {
+	echo "`basename $0` [-g] [-t] <conf_path>"
+	exit 1
+}
+
+restore() {
+	restore_gateway
+	restore_dns
+}
+
+restore_gateway() {
+	echo "INFO: check_gateway"
+	gw_cur=`ip route show 0/0 |cut -d' ' -f3`
+	echo "INFO: gw_cur=$gw_cur"
+	if [ "$gw_before" != "$gw_cur" ]; then
+		echo "INFO: Gateway changed (before=$gw_before, cur=$gw_cur)"
+		echo "INFO: Restoring previous default gw"
+		/usr/sbin/ip route delete default
+		/usr/sbin/ip route add default via $gw_before
+	fi
+}
+
+restore_dns() {
+	echo "INFO: check_dns"
+	if [ -f /etc/resolv.conf.bak-covpn ]; then
+		echo "INFO: restoring previous DNS"
+		mv /etc/resolv.conf.bak-covpn /etc/resolv.conf
+	fi
+}
+
+if [ `id -u` -ne 0 ]; then
+	echo "must be root"
+	exit 1
+fi
+
+gw_before=`ip route show 0/0 |cut -d' ' -f3`
+
+opts="$(getopt -o gth -l gateway,tcp,help -n "$program" -- "$@")"
+openvpn_proto="udp"
+gateway=0
+err=$?
+echo "INFO: gw_before=$gw_before"
+eval set -- "$opts"
+while true; do case $1 in
+	-g|--gateway) gateway=1; shift;;
+	-t|--tcp) openvpn_proto="tcp"; shift ;;
+	-h|--help) usage_exit ;;
+	--) shift; break ;;
+esac done
+test $err -ne 0 && usage_exit
+test $# -lt 1 && usage_exit
+conf_path=`readlink -f $1`
+shift
+
+covpn_conf="$conf_path/covpn.conf"
+if [ ! -f $covpn_conf ]; then
+	echo "ERROR: missing covpn.conf in $conf_path !"
+	exit 1
+fi
+. $covpn_conf
+
+if [ $openvpn_proto = "udp" ]; then
+	openvpn_remote="$CONF_UDP_REMOTE"
+else
+	openvpn_remote="$CONF_TCP_REMOTE"
+fi
+
+trap restore INT TERM EXIT
+
+/usr/sbin/openvpn --setenv openvpn_gateway $gateway \
+	 --setenv covpn_conf $covpn_conf \
+	--cd $conf_path --config openvpn.conf --chroot $conf_path \
+	--proto $openvpn_proto --remote $openvpn_remote $@
+