Update Script for openvpn

want to set client connection limit, so that only 3 device from user can connect at a time. please see example: [login to view URL] -or- [login to view URL] client-connect scripts/[login to view URL] # #!/bin/bash . /etc/openvpn/scripts/[login to view URL] . /etc/openvpn/scripts/[login to view URL] common_name=$(echap "$common_name") trusted_ip=$(echap "$trusted_ip") trusted_port=$(echap "$trusted_port") ifconfig_pool_remote_ip=$(echap "$ifconfig_pool_remote_ip") remote_port_1=$(echap "$remote_port_1") bytes_received=$(echap "$bytes_received") bytes_sent=$(echap "$bytes_sent") # Prevent the error : ERROR 1366 (22007) at line 1: Incorrect double value: '' for column 'log_received' at row 1 if [ -z "$bytes_received" ] then bytes_received=0 fi if [ -z "$bytes_sent" ] then bytes_sent=0 fi # We insert data in the log table mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "INSERT INTO log (log_id, user_id, log_trusted_ip, log_trusted_port, log_remote_ip, log_remote_port, log_start_time, log_end_time, log_received, log_send) VALUES(NULL, '$common_name','$trusted_ip', '$trusted_port','$ifconfig_pool_remote_ip', '$remote_port_1', now(),NULL, '$bytes_received', '$bytes_sent')" # We specify that the user is online mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "UPDATE user SET user_online=1 WHERE user_id='$common_name'" # client-disconnect scripts/[login to view URL] # #!/bin/bash . /etc/openvpn/scripts/[login to view URL] . /etc/openvpn/scripts/[login to view URL] common_name=$(echap "$common_name") bytes_received=$(echap "$bytes_received") bytes_sent=$(echap "$bytes_sent") trusted_ip=$(echap "$trusted_ip") trusted_port=$(echap "$trusted_port") # We specify the user is offline mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "UPDATE user SET user_online=0 WHERE user_id='$common_name'" # We insert the deconnection datetime mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "UPDATE log SET log_end_time=now(), log_received='$bytes_received', log_send='$bytes_sent' WHERE log_trusted_ip='$trusted_ip' AND log_trusted_port='$trusted_port' AND user_id='$common_name' AND log_end_time IS NULL" #