#!/bin/sh

: <<EOF

=head1 NAME

ntp_kernel_pll_freq - Plugin to monitor the kernel's PLL frequency for
the NTP status

=head1 CONFIGURATION

No configuration

This plugin optionally reads the file /etc/munin/ntp-freq-comp, which
should contain a number to be added to the frequency read by ntpdc.

=head1 AUTHORS

Unknown author

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf

=cut

EOF

export PATH=/usr/local/sbin:$PATH

if [ "$1" = "autoconf" ]; then
    { ntpq -c kerninfo; ntpdc -c kerninfo; } 2>/dev/null |
    awk 'BEGIN { ev=1; }
         /^pll frequency:/ { ev=0; }
         END { if (ev == 0) { print "yes";} else { print "no (command ntpq or ntpdc not found)"; } exit 0; }'
    exit 0
fi

if [ -f /etc/munin/ntp-freq-comp ]; then
    fcomp=$(cat "/etc/munin/ntp-freq-comp")
else
    fcomp=0
fi

if [ "$1" = "config" ]; then
    echo 'graph_title NTP kernel PLL frequency (ppm +' ${fcomp}')'
    echo 'graph_args --alt-autoscale'
    echo 'graph_vlabel PLL frequency (ppm +' ${fcomp}')'
    echo 'graph_category time'
    echo 'graph_info The frequency for the kernel phase-locked loop used by NTP.'
    echo 'ntp_pll_freq.label pll-freq'
    echo 'ntp_pll_freq.info Phase-locked loop frequency in parts per million'
    exit 0
fi

printf 'ntp_pll_freq.value '

ntpq_name=$(ntpq -c version | sed 's/[^[:alpha:]].*//')
ntpq_version=$(ntpq -c version | grep --extended-regexp --only-matching '[[:digit:]]\.[[:digit:]]\.[[:digit:]]')
if [ "$ntpq_name" = "ntpq" ] && [ "$(echo "$ntpq_version" | tr -d '.')" -lt 427 ]; then
    cmd=ntpdc
else
    cmd=ntpq
fi

"$cmd" -c kerninfo | awk -v "fcomp=$fcomp" '/^pll frequency:/ { printf("%.9f\n", $3 + fcomp) }'