#!/bin/sh
# Please make sure the paths below are correct.
# shellcheck disable=SC2016 # AWK program strings — $BIN_AWK indirection hides awk from shellcheck
# Alternatively you can put them in $0.conf, meaning if you've named
# this script ntp-client.sh then it must go in ntp-client.sh.conf .
#
# NTPQV output version of "ntpq -c rv"
# p1 DD-WRT and some other outdated linux distros
# p11 FreeBSD 11 and any linux distro that is up to date
#
# If you are unsure, which to set, run this script and make sure that
# the JSON output variables match that in "ntpq -c rv".
#
BIN_NTPD='/usr/bin/env ntpd'
BIN_NTPQ='/usr/bin/env ntpq'
BIN_NTPDC='/usr/bin/env ntpdc'
BIN_GREP='/usr/bin/env grep'
BIN_TR='/usr/bin/env tr'
BIN_CUT='/usr/bin/env cut'
BIN_SED="/usr/bin/env sed"
BIN_AWK='/usr/bin/env awk'
NTPQV="p11"
################################################################
# Don't change anything unless you know what are you doing     #
################################################################
CONFIG="$0.conf"
if [ -f "$CONFIG" ]; then
    . "$CONFIG"
fi
VERSION=1

STRATUM=$("$BIN_NTPQ" -c rv | "$BIN_GREP" -Eow "stratum=[0-9]+" | "$BIN_CUT" -d "=" -f 2)

# parse the ntpq info that requires version specific info
NTPQ_RAW=$("$BIN_NTPQ" -c rv | "$BIN_GREP" jitter | "$BIN_SED" 's/[[:alpha:]=,_]/ /g')
if [ "$NTPQV" = "p11" ]; then
	OFFSET=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $3}')
	FREQUENCY=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $4}')
	SYS_JITTER=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $5}')
	CLK_JITTER=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $6}')
	CLK_WANDER=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $7}')
fi
if [ "$NTPQV" = "p1" ]; then
	OFFSET=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $2}')
	FREQUENCY=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $3}')
	SYS_JITTER=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $4}')
	CLK_JITTER=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $5}')
	CLK_WANDER=$(echo "$NTPQ_RAW" | "$BIN_AWK" -F ' ' '{print $6}')
fi

VER=$("$BIN_NTPD" --version)
if [ "$VER" = '4.2.6p5' ]; then
  USECMD="$BIN_NTPDC -c iostats"
else
  USECMD="$BIN_NTPQ -c iostats localhost"
fi
CMD2=$($USECMD | "$BIN_TR" -d ' ' | "$BIN_CUT" -d : -f 2 | "$BIN_TR" '\n' ' ')

TIMESINCERESET=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $1}')
RECEIVEDBUFFERS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $2}')
FREERECEIVEBUFFERS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $3}')
USEDRECEIVEBUFFERS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $4}')
LOWWATERREFILLS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $5}')
DROPPEDPACKETS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $6}')
IGNOREDPACKETS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $7}')
RECEIVEDPACKETS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $8}')
PACKETSSENT=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $9}')
PACKETSENDFAILURES=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $10}')
INPUTWAKEUPS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $11}')
USEFULINPUTWAKEUPS=$(echo "$CMD2" | "$BIN_AWK" -F ' ' '{print $12}')

echo '{"data":{"offset":"'"$OFFSET"\
'","frequency":"'"$FREQUENCY"\
'","sys_jitter":"'"$SYS_JITTER"\
'","clk_jitter":"'"$CLK_JITTER"\
'","clk_wander":"'"$CLK_WANDER"\
'","stratum":"'"$STRATUM"\
'","time_since_reset":"'"$TIMESINCERESET"\
'","receive_buffers":"'"$RECEIVEDBUFFERS"\
'","free_receive_buffers":"'"$FREERECEIVEBUFFERS"\
'","used_receive_buffers":"'"$USEDRECEIVEBUFFERS"\
'","low_water_refills":"'"$LOWWATERREFILLS"\
'","dropped_packets":"'"$DROPPEDPACKETS"\
'","ignored_packets":"'"$IGNOREDPACKETS"\
'","received_packets":"'"$RECEIVEDPACKETS"\
'","packets_sent":"'"$PACKETSSENT"\
'","packet_send_failures":"'"$PACKETSENDFAILURES"\
'","input_wakeups":"'"$INPUTWAKEUPS"\
'","useful_input_wakeups":"'"$USEFULINPUTWAKEUPS"\
'"},"error":"0","errorString":"","version":"'"$VERSION"'"}'