#!/bin/bash
# -*- sh -*-

: <<=cut

=head1 NAME

dnsmasq - Plugin to monitor dnsmasq queries

=head1 APPLICABLE SYSTEMS

All systems with "bash", "sed" and "dnsmasq"

=head1 CONFIGURATION

The following is the default configuration

  [dnsmasq]
  env.logfile /var/log/dnsmasq/dnsmasq.log

The user running this plugin needs read access to the
dnsmasq logfiles:

  [dnsmasq]

  user root

  =head1 INTERPRETATION

This plugin shows a graph with the number of forwarded, cached and 
blocked dns queries.

=head1 MAGIC MARKERS

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

=head1 VERSION
  0.0.1

=head1 BUGS

=head1 AUTHOR

Me, myself and I
Based on dnsmasq plugin by: notracking <https://github.com/notracking>
Based on fail2ban plugin by: Stig Sandbeck Mathisen <ssm@fnord.no>

=head1 LICENSE

GPLv2

=cut


##############################
# Configurable variables
logfile=${logfile:-/var/log/dnsmasq/dnsmasq.log}

# Print the munin values
values() {
    echo -n "dnsmasq_forwarded.value "
    cat ${logfile} | sed -n "/^$(date --date='5 minutes ago' '+%b %_d %H:%M')/,\$p" | grep ": forwarded" | wc -l

    echo -n "dnsmasq_cached.value "
    cat ${logfile} | sed -n "/^$(date --date='5 minutes ago' '+%b %_d %H:%M')/,\$p" | grep ": cached" | wc -l

    echo -n "dnsmasq_blocked.value "
    cat ${logfile} | sed -n "/^$(date --date='5 minutes ago' '+%b %_d %H:%M')/,\$p" | grep "/block.list" | wc -l
}

# Print the munin config
config() {
    echo 'graph_title DNS queries'
    echo 'graph_info This graph shows the number of queries resolved by dnsmasq'
    echo 'graph_category network'
    echo 'graph_vlabel Number of queries'

    echo 'graph_args --base 1000 -l 0'
    echo 'graph_total total'

    echo 'dnsmasq_forwarded.label forwarded'
    echo 'dnsmasq_cached.label cached'
    echo 'dnsmasq_blocked.label blocked'
}

# Print autoconfiguration hint
autoconf() {
    if [ -f ${logfile} ]
    then
        echo "yes"
    else
        echo "no (${logfile} not found)"
    fi
    exit
}

##############################
# Main

case $1 in
    config)
        config
        ;;
    autoconf)
        autoconf
        ;;
    *)
        values
        ;;
esac