#!/bin/bash
##
## Munin plugin to return the transfer in bytes of each user.
##
## The 'openvpn_usertransfer' config stanza for munin-node looks like:
##
### [openvpn_usertransfer]
### user root
### env.statusfile "/var/log/openvpn-status.log"
##
## You can watch mutiple OpenVPN networks by aliasing openvpn_usertranfer script
## to "openvpn_usertransfer_network.vpn" where "network.vpn" is the OpenVPN
## network name.
##
### [openvpn_usertransfer_network.vpn]
### user root
### env.statusfile "/var/log/openvpn/network.vpn/openvpn-status.log"
##
## Original Author: Jeffrey Forman ( https://github.com/jforman )
## Enhanced by : Pierre-Yves Landuré for Biapy ( https://github.com/biapy )
##

# Compute statusfile option.
OPENVPN_STATUS_FILE="/var/log/openvpn-status.log"
if [ -n "${statusfile}" ]; then
  OPENVPN_STATUS_FILE="${statusfile}"
fi

# Check for status log existance.
if [ ! -e "${OPENVPN_STATUS_FILE}" ]; then
  echo "Error: OpenVPN status file '${OPENVPN_STATUS_FILE}' does not exist"
  exit 1
fi

# Detect VPN network name from script name.
NETWORK_NAME="$(command basename "${0}" \
    | command sed -e 's/openvpn_usertransfer[_]\{0,1\}//')"
if [ -n "${NETWORK_NAME}" ]; then
  NETWORK_NAME=" (${NETWORK_NAME})"
fi

# Detect status log version.
STATUS_LOG_VERSION="3"
if [ -n "$(command grep "CLIENT LIST" "${OPENVPN_STATUS_FILE}")" ]; then
  STATUS_LOG_VERSION="1"
elif [ -n "$(command grep "HEADER,CLIENT_LIST," "${OPENVPN_STATUS_FILE}")" ]; then
  STATUS_LOG_VERSION="2"
fi


case "${1}" in

  "config" )
    # Display munin-node plugin configuration.
    echo "graph_title OpenVPN User Transfer Rate${NETWORK_NAME}
graph_vlabel Bytes Received / Bytes Sent
graph_category openvpn
graph_info Show the data transfer over the VPN per user."
    case "${STATUS_LOG_VERSION}" in
        "1" )
          CLIENT_LIST="$(command sed -e '0,/Common Name/d' \
              -e '/ROUTING TABLE/,/END/d' \
              -e 's/^\([^,]*\),.*$/\1/' \
              "${OPENVPN_STATUS_FILE}")"
          ;;
        "2" | "3" )
          CLIENT_LIST="$(command grep "^CLIENT_LIST" ${OPENVPN_STATUS_FILE} \
              | command sed -e 's/^CLIENT_LIST[,\t]\([^,\t]*\)[\t,].*$/\1/')"
          ;;
        * )
          CLIENT_LIST=""
          ;;
    esac
    for CLIENT in ${CLIENT_LIST}; do
        CLIENT_CODE="${CLIENT//[^0-9A-Za-z]/_}"
        echo "${CLIENT_CODE}_received.label ${CLIENT}
${CLIENT_CODE}_received.type DERIVE
${CLIENT_CODE}_received.min 0
${CLIENT_CODE}_received.graph no
${CLIENT_CODE}_received.draw LINE2
${CLIENT_CODE}_sent.label ${CLIENT}
${CLIENT_CODE}_sent.type DERIVE
${CLIENT_CODE}_sent.min 0
${CLIENT_CODE}_sent.negative ${CLIENT_CODE}_received
${CLIENT_CODE}_sent.draw LINE2"
    done
    exit 0
    ;;


  * )
    # Default action.
    case "${STATUS_LOG_VERSION}" in
        "1" )
          CLIENT_LIST="$(command sed -e '0,/Common Name/d' \
              -e '/ROUTING TABLE/,/END/d' \
              "${OPENVPN_STATUS_FILE}")"
          ;;
        "2" | "3" )
          CLIENT_LIST="$(command grep "^CLIENT_LIST" ${OPENVPN_STATUS_FILE} \
              | command tr "\t" ",")"
          ;;
        * )
          CLIENT_LIST=""
          ;;
    esac

    # exit if no data.
    test -z "${CLIENT_LIST}" && exit 0

    echo "${CLIENT_LIST}" | while read LINE; do
      case "${STATUS_LOG_VERSION}" in
          "1" )
            CLIENT="$(command echo "${LINE}" | command cut --delimiter="," --field="1")"
            RECEIVED="$(command echo "${LINE}" | command cut --delimiter="," --field="3")"
            SENT="$(command echo "${LINE}" | command cut --delimiter="," --field="4")"
            ;;
          "2" | "3" )
            CLIENT="$(command echo "${LINE}" | command cut --delimiter="," --field="2")"
            RECEIVED="$(command echo "${LINE}" | command cut --delimiter="," --field="5")"
            SENT="$(command echo "${LINE}" | command cut --delimiter="," --field="6")"
            ;;
      esac
      CLIENT_CODE="${CLIENT//[^0-9A-Za-z]/_}"

      echo "${CLIENT_CODE}_received.value ${RECEIVED}
${CLIENT_CODE}_sent.value ${SENT}"
    done
    ;;
esac