#!/bin/sh

# This you can add to crontab:
#	@reboot /path/to/ssh_tun.sh >> /tmp/ssh_tun.tmp
#	* * * * * /opt/start_ssh_tunnel.sh >> /tmp/ssh_tun.tmp

# Configure:
KEY_PATH=/absolute/path/to/key
USER=tun-user
ADDR=my.domain.org
LISTEN_PORT=12345

# Don't change below:
GATEWAY="$LISTEN_PORT:127.0.0.1:22"
OPT='-o PubkeyAuthentication=yes -o IdentitiesOnly=yes'
FLAGS='-f -T -N -R'

SSH_TUN_CMD="ssh $OPT $FLAGS $GATEWAY $USER@$ADDR -i $KEY_PATH"

pgrep -f "$SSH_TUN_CMD"
if [ $? -eq 0 ]; then
        exit 0
fi

ping -c 3 $ADDR
if [ $? -ne 0 ]; then
        exit 1
fi

exec $SSH_TUN_CMD