Help with auto switching VPN servers

[toyebox]

Hey all! You have never let me down here ! Before I go through the trouble of trying to write a bash script, I thought I would ask here first. I have about 10 different openVPN Servers I connect to. Sometimes one will go down and I want to set up an auto switching between the servers. I have it setup so when not connected to a VPN, there is no internet access for that jail. I'm trying to minimize down time. Any thoughts appreciated!

 

[toyebox]

well, i decided to just write up a bash script. i run it with a cron job. here it is for anyone who wants it. i know its not perfect btw, but it does work well.

Code:

#!/usr/local/bin/bash

#__________ Don't edit below this!!!__________

# Edit these var's by using command line arguments -r, -w and -c
timeBetweenResets=60
timeToWaitForTun=45
userSetConfig=null
vpns=(US.conf Canada.conf Russia.conf);

initiateNewTun () {
	totalLength=${#vpns[@]}
	oldPos=null

	# Read the file of the last used server
	mapfile -t < /home/admin/last_used_server lines
	oldValue="${lines[0]}"
	oldTime="${lines[1]}"
	newTime=`date +%s`
	
	# Check to make sure that the info file contains a time in seconds and a last used server, if not, create it
	rc='^[0-9]+$'
	if [[ ! $oldTime =~ $rc ]] || [[ ${oldValue} != *".conf"* ]]; then
		echo "error: corrupt last_used_server file.. resetting it"
		cat > /home/admin/last_used_server <<- EOF
		${vpns[0]}
		$newTime
		EOF
		
		# Set oldTime to 0 so the script will continue and ignore the timeBetweenResets var
		oldTime=0
		lastConf=$(($totalLength -1))
		oldValue=${vpns[$lastConf]}
		echo "Set oldValue and oldTime so the script will continue.."
	fi

	# Specific script for setting a user set config (must match one of the ones in the array)
	if [[ $userSetConfig != null ]]; then
		for i in "${!vpns[@]}"; do
			if [[ "${vpns[$i]}" = "${userSetConfig}" ]]; then
				userInputIsGood=true	
			fi
		done
	
		if [[ $userInputIsGood == true ]]; then
			echo "the user input config name is available, we will set it now."
			newValue=$userSetConfig
		fi

	# Specific script if NOT setting a user specific script
	else
		difference=$(($newTime - $oldTime))
	
		if [[ $difference -lt $timeBetweenResets ]]; then
			echo "too soon between resets, exiting.."
			exit
		fi

			for i in "${!vpns[@]}"; do
			  if [[ "${vpns[$i]}" = "${oldValue}" ]]; then
					oldPos="${i}";
			fi
			done

		if [[ $oldPos == null ]]; then
			echo "Current config was not found in array.. resetting to the first config.."
			newPos=0
		else
			nextPos=$(($oldPos + 1)) 
		
			if [[ $nextPos -eq $totalLength ]]; then
				echo "there is no next config, need to circle back to the beginning"
				nextPos=0
			fi
		fi
		
		# set the new config value		
		newValue=${vpns[$nextPos]}
	fi

	# Update last_server_used file info
	echo "Next config to use is: $newValue , Updating last_used_server file"
	cat > /home/admin/last_used_server <<- EOF
	$newValue
	$newTime
	EOF
	
	/usr/local/sbin/openvpn --daemon openvpn --config /usr/local/etc/openvpn/$newValue --writepid /var/run/openvpn.pid
	return 0
}

killAllTuns () {
	# First kill all openvpn services so we don't lock up when trying to remove tunnels
	for pid in $(ps -xj | grep "openvpn" | grep -v "grep" | awk '{print $2}'); do 
		kill -9 $pid
		echo "killed pid: $pid" 
	done
	
	# Check to see if all openvpn instances were closed out (the tunnel will not show UP in the description)
	if ifconfig | grep "tun" | grep "UP" > /dev/null; then
		echo "failed to kill all openvpn instances, exiting.."
		exit
	fi

	# Destroy all empty tunnel interfaces
	for tuns in $(/sbin/ifconfig -l | tr " " "\n" | grep "tun"); do ifconfig $tuns destroy; done
	
	# Verify all tunnels were removed
		if ifconfig | grep "tun" > /dev/null; then
				echo "failed to kill all tunnels, exiting.."
				exit	
		fi

	echo "Successfully reset all interfaces"
}

checkInternet () 
{
	wget -q --tries=5 --timeout=30 --spider http://google.com
	if [[ $? -eq 0 ]]; then
		return 0
	else
		return 1
	fi
}

# ________________________________________________________________Main Run Starts Here ____________________________________________
# Check for options that were run
while getopts ":c:r:w:" opt; do
	case $opt in
		c ) userSetConfig=$OPTARG ;;
		r ) timeBetweenResets=$OPTARG ;;
		w ) timeToWaitForTun=$OPTARG ;;
		* ) echo "incorrect argument, exiting.."
			exit 1
	esac
done

# When setting a specific user config, don't check for internet connection, just do it
if [[ $userSetConfig == null ]]; then
	# Check if everything is working properly
	checkInternet

	# return 0 means all is healthy and we are connected; exit the script
	if [[ $? -eq 0 ]]; then
			exit
	fi

	echo "Internet is not up and running.. Starting reset procedures"
fi

# Kill all active tunnels and instances of OpenVPN
killAllTuns

# Initiate a new tunnel using the next config				
initiateNewTun

if [[ $? -eq 0 ]]; then
	echo "Waiting for tunnel device to appear.."
	
	tunAvail=null
		end=$((SECONDS+$timeToWaitForTun))

		while [ $SECONDS -lt $end -a $tunAvail == null ]; do
				tunAvail=$(/sbin/ifconfig -l | tr " " "\n" | /usr/bin/grep 'tun')

				if [[ $tunAvail != *"tun"* ]]; then
						tunAvail=null
				fi

				sleep 1
		done

	if ! ifconfig | grep "tun" | grep "UP" > /dev/null; then
				echo "No tunnel found.. Failed to initiate a new tunnel.. Exiting.."
		exit
		fi

	echo "tunnel created successfully, setting firewall and checking internet connection.."
	service ipfw restart
	checkInternet
	
	if [[ $? -eq 0 ]]; then
		echo "Internet restoration complete, exiting"
	else
		echo "internet restoration was unsuccessful, exiting"
	fi
	
	exit
fi

echo "initiateNewTun failed with an unknown reason"
exit