#! /bin/bash
#
# wiperf_switcher       script to switch wiperf on/off
#
# Written by Nigel Bowden <wifinigel@gmail.com>.
#

set -e

NAME=wiperf_switcher
DESC="Script to switch wiperf mode on/off"
STATUS_FILE="/etc/wlanpi-state"

HOME_DIR="/usr/share/wiperf"
USERNAME="root"
CFG_DIR="/etc/wiperf"
CFG_FILE="$CFG_DIR/config.ini"
LOG_FILE="/var/log/wiperf_switcher.log"
ROUTE_FILE="/etc/network/if-up.d/route"

# Check we're root
if [[ $EUID -ne 0 ]]; then
   err_msg="This script must be run as root" 
   echo $err_msg | tee $LOG_FILE
   exit 1
fi

###############################################################################
#
# Activate wiperf:
#
# 1.  Check that a mode is defined in config.ini
# 2.  Check interface wlan0 is available (wireless NIC plugged in)
#       a. wlan0 - wireless NIC available
#       b. eth0 - ethernet port available
# 3.  Read in test interval & offset from config file
# 4.  Add crontab entry to perform 5 min polling
# 5.  Add fw rules to harden eth0 & wlan0
# 6.  Backup various existing files to allow restoration when wiperf
#     deactivated
# 7. Move a number of existing files that need to be replaced
# 8. Create status file to indicate wiperf is active
# 9. Reboot the wlanpi to ensure clean activation
#
# Note: /etc/sysctl.conf included to ensure forwarding
#    cannot be accidentally be enabled in probe mode if
#    has been changed by some other process
#
###############################################################################
wiperf_on () {

  echo "Starting switch from classic mode to wiperf mode" | tee $LOG_FILE

  # check what state the WLAN Pi is in classic mode
  PI_STATUS=`cat $STATUS_FILE | grep 'classic'` || true
  if  [ -z "$PI_STATUS" ]; then
     echo "Failed - WLAN Pi is not in classic mode. (exiting)"  | tee -a $LOG_FILE
     exit 1
  fi

  ############################################
  # 1. Get the probe mode (ethernet/wireless)
  ############################################
  MODE=`cat ${CFG_FILE} | grep 'probe_mode:' | awk -F'[: ]*' '{print $2}'` || true
  if  [ -z "$MODE" ]; then
    echo "No mode found in config file (exiting)" | tee -a $LOG_FILE 
    exit 1
  else
    echo "Selected mode in cfg file: ${MODE}" | tee -a $LOG_FILE 
  fi

  #######################################################################
  # 2. Check if wlan or eth interface is available (depending on config)
  #######################################################################
  echo "Checking expected interfaces are available..."  | tee -a $LOG_FILE
  if [ "$MODE" = "ethernet" ]; then
    # Check if eth0 available before we start changing things 
    TESTING_IF=`ip a | grep eth0` || true
    if  [ -z "$TESTING_IF" ]; then
      echo "No Eth Interface available! (exiting)" | tee -a $LOG_FILE 
      exit 1
    fi
    echo "Ethernet details: ${TESTING_IF}" | tee -a $LOG_FILE
  else
    # Check if wlan0 available before we start changing things 
    TESTING_IF=`ip a | grep wlan0` || true
    if  [ -z "$TESTING_IF" ]; then
      echo "No WLAN Interface available! (exiting)" | tee -a $LOG_FILE 
      exit 1
    fi
    echo "WLAN details ${TESTING_IF}" | tee -a $LOG_FILE
  fi

  #######################################
  # 3. Get test interval & offset value
  #######################################
  TEST_INTERVAL=`cat ${CFG_FILE} | grep 'test_interval:' | awk -F'[: ]*' '{print $2}'` || true
  if  [ -z "TEST_INTERVAL" ]; then
    echo "No test interval in config file (exiting)" | tee -a $LOG_FILE 
    exit 1
  fi
  echo "Test interval from config file: ${TEST_INTERVAL}" | tee -a $LOG_FILE

  # Get test offset value
  TEST_OFFSET=`cat ${CFG_FILE} | grep 'test_offset:' | awk -F'[: ]*' '{print $2}'` || true
  if  [ -z "TEST_OFFSET" ]; then
    echo "No test offset in config file (exiting)" | tee -a $LOG_FILE 
    exit 1
  fi
  echo "Test offset from config file: ${TEST_OFFSET}" | tee -a $LOG_FILE

  ########################
  # 4. Add crontab entry
  ########################
  # add crontab if does not exist already
  if ! [ -e  /var/spool/cron/crontabs/$USERNAME ]; then
    echo "# " | crontab -u $USERNAME -
  fi

  line="${TEST_OFFSET}-59/${TEST_INTERVAL} * * * * /usr/bin/python3 ${HOME_DIR}/wiperf_run.py > /var/log/wiperf_cron.log 2>&1"
  (crontab -u $USERNAME -l; echo "$line" ) | crontab -u $USERNAME -
  LAST_RESULT=$?
  if [ $LAST_RESULT -ne 0 ]; then
    echo "Cron add failed" | tee -a $LOG_FILE 
    exit 0
  fi
  echo "Cron command added: ${line}" | tee -a $LOG_FILE

  #################################################################################
  # 5. Harden eth0 & wlan0 by adding fw rules - allow only ssh in on eth0 & wlan0
  #################################################################################
  ufw insert 1 allow in on eth0 to any port ssh
  ufw insert 2 allow in on eth0 to any port http
  ufw insert 3 deny in on eth0
  ufw insert 4 allow in on wlan0 to any port ssh
  ufw insert 5 allow in on wlan0 to any port http
  ufw insert 6 deny in on wlan0

  ##################################
  # 6. Backup existing config files
  ##################################
  declare -a arr=(
      "/etc/network/interfaces" 
      "/etc/sysctl.conf"
      "/etc/wpa_supplicant/wpa_supplicant.conf"
  )
  echo "Backing up config files..." | tee -a $LOG_FILE

  for item in "${arr[@]}"
  do
    if [ -f "$item" ]; then
      mv $item ${item}.probe
    fi
  done

  ##################################
  # 7. Link to wiperf config files
  ##################################
  echo "Linking temp config files..." | tee -a $LOG_FILE
  ln -s ${CFG_DIR}/conf/etc/network/interfaces /etc/network/interfaces  
  ln -s ${CFG_DIR}/conf/etc/wpa_supplicant/wpa_supplicant.conf /etc/wpa_supplicant/wpa_supplicant.conf
  ln -s ${CFG_DIR}/conf/etc/sysctl.conf /etc/sysctl.conf

  ############################################################
  # 8. Create status file to display status messages on FPMS
  ############################################################
  echo "Updating status file." | tee -a $LOG_FILE

  # Signal that wconsole active
  echo "wiperf" > $STATUS_FILE

  #############
  # 9. Reboot 
  #############
  echo "WLAN Pi will now reboot" | tee -a $LOG_FILE
  sleep 1
  sync
  reboot
}

###############################################################################
#
# Deactivate wiperf:
#
# 1. Get the probe mode
# 2. Remove crontab entry to stop polling
# 3. Remove fw rules added during mode switch
# 4. Remove links created during activation
# 5. Restore config files backed up during activation
# 6. Remove status file to indicate wiperf no longer active
# 7. Reboot wlanpi to provide clean restoration of services
#
###############################################################################
wiperf_off () {

  # check what state the WLAN Pi is in
  PI_STATUS=`cat $STATUS_FILE | grep 'wiperf'` || true
  if  [ -z "$PI_STATUS" ]; then
     echo "Failed - WLAN Pi is not in wiperf mode. (exiting)" | tee -a $LOG_FILE
     exit 1
  fi

   echo "Starting switch from wiperf mode to classic mode" | tee -a $LOG_FILE

  ############################################
  # 1. Get the probe mode (ethernet/wireless)
  ############################################
  MODE=`cat ${CFG_FILE} | grep 'probe_mode:' | awk -F'[: ]*' '{print $2}'` || true
  if  [ -z "$MODE" ]; then
    echo "No mode found in config file (exiting)" | tee -a $LOG_FILE 
    exit 1
  fi

  echo "Selected mode in cfg file: ${MODE}" | tee -a $LOG_FILE
  
  ###########################################
  # 2. Remove crontab entry to stop polling
  ###########################################
  echo "Removing cron job." | tee -a $LOG_FILE
  crontab -u $USERNAME -l | grep -v 'wiperf_run.py'  | crontab -u $USERNAME -
  LAST_RESULT=$?
  if [ $LAST_RESULT -ne 0 ]; then
    echo "Cron remove failed (exiting)" | tee -a $LOG_FILE 
    exit 1
  fi
  
  echo "Cron entry removed" | tee -a $LOG_FILE
  
  ##################################
  # 3. Remove eth0 & wlan0 fw rules
  ##################################
  ufw delete allow in on eth0 to any port ssh
  ufw delete allow in on eth0 to any port http
  ufw delete deny in on eth0
  ufw delete allow in on wlan0 to any port ssh
  ufw delete allow in on wlan0 to any port http
  ufw delete deny in on wlan0

  ##################################
  # 4. Remove links to config files
  ##################################
  echo "Removing links to temp config files" | tee -a $LOG_FILE
  unlink /etc/network/interfaces
  unlink /etc/sysctl.conf
  unlink /etc/wpa_supplicant/wpa_supplicant.conf
 
  ###################################
  # 5. Restore original config files
  ###################################
  declare -a arr=(
      "/etc/network/interfaces" 
      "/etc/sysctl.conf"
      "/etc/wpa_supplicant/wpa_supplicant.conf"
  )

  echo "Restoring original config files" | tee -a $LOG_FILE

  for item in "${arr[@]}"
  do
    if [ -f "${item}.probe" ]; then
      mv ${item}.probe $item
    fi
  done

  ###################################
  # 6. Update FPMS status file
  ###################################
  echo "WLANPi will now reboot"
  echo "classic" > $STATUS_FILE

  ###################################
  # 7. Reboot
  ###################################
  echo "Rebooting" | tee -a $LOG_FILE
  sleep 1
  sync
  reboot
}

status () {
  PI_STATUS=`cat $STATUS_FILE | grep 'wiperf'` || true
  if  [ -z "$PI_STATUS" ]; then
    echo "wiperf is currently disabled"
    exit 0
  else
    echo "wiperf is currently enabled"
    exit 0
  fi
}

case "$1" in
  on)
        wiperf_on
        ;;
  off)
        wiperf_off
        ;;
  status)
        status
        ;;
  *)
        N=/usr/share/wiperf/$NAME
        echo "Usage: $N {on|off|status|version}" >&2
        exit 0
        ;;
esac

exit 0