#!/bin/sh -u
# -*- sh -*-

: << =cut

=head1 NAME

upnpc_ - Plugin to monitor routers via UPnP

This plugin uses the upnpc utility (package miniupnpc in Debian), to monitor an
router using UPnP. It can monitor the following aspects, and plot them as separate graphs:
* uptime: how long the link has been up;
* bitrate: the up and downlink bitrate (e.g., sync speed for DSL);
* traffic: the actual up and downstream traffic rate;
* pkts: the number of packets coming in and out.

=head1 APPLICABLE SYSTEMS

Linux systems with upnpc installed (miniupnpc package).

=head1 CONFIGURATION

If you do not want to show the link maximum bitrates, add the following
plugin-configuration:

  [upnpc*]
    env.traffic_remove_max true

=head1 AUTHOR

Olivier Mehani

Copyright (C) 2016,2019 Olivier Mehani <shtrom+munin@ssji.net>

=head1 LICENSE

SPDX-License-Identifier: GPL-3.0-or-later

=head1 MAGIC MARKERS

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

=cut

if [ "${MUNIN_DEBUG:-0}" = 1 ]; then
    set -x
fi

if ! command -v upnpc >/dev/null; then
	echo "upnpc not found (miniupnpc package)" >&2
	exit 1
fi

PLUGIN_NAME="$(basename "${0}")"
MODE="$(echo "${PLUGIN_NAME}" | sed 's/.*_//')"
DATA="$(upnpc -s)"
SUPPORTED_MODES=$(
	echo "${DATA}" | sed -n " \
		s/.*Bytes.*/traffic/p; \
		s/.*Packets.*/pkts/p; \
		s/.*uptime=.*/uptime/p; \
	")

autoconf() {
	test -n "${DATA}" && echo yes || echo "no (No UPnP router detected)"
}

suggest () {
	for mode in ${SUPPORTED_MODES}; do
		echo "${mode}"
	done
}

config () {
	case ${1} in
		"uptime")
			cat << EOF
graph_title Uplink connection uptime
graph_args -l 0
graph_category network
graph_scale no
graph_vlabel uptime in hours
uptime.label uptime
uptime.draw AREA
uptime.cdef uptime,3600,/
EOF
			;;
		"bitrate")
			cat << EOF
graph_title [DEPRECATED] Uplink bitrate
graph_args --base 1000 -l 0
graph_category network
graph_vlabel bitrate down (-) / up (+)
down.label bps
up.label bps
down.graph no
up.negative down
EOF
			;;
		"traffic")
			# ${graph_period} is not a shell variable
			cat << 'EOF'
graph_title Uplink traffic
graph_args --base 1000 -l 0
graph_category network
graph_vlabel bytes in (-) / out (+) per ${graph_period}
EOF
			if [ "${traffic_remove_max:-false}" != 'true' ]; then
				cat << EOF
maxdown.label bps (max)
maxup.label bps (max)
maxdown.graph no
maxup.negative maxdown
EOF
			fi
			cat << EOF
down.label bps
down.type DERIVE
down.min 0
down.cdef down,8,*
up.label bps
up.type DERIVE
up.min 0
up.cdef up,8,*
down.graph no
up.negative down
EOF
			;;
		"pkts")
			# ${graph_period} is not a shell variable
			cat << 'EOF'
graph_title Uplink packets
graph_args --base 1000 -l 0
graph_category network
graph_vlabel packets in (-) / out (+) per ${graph_period}
down.label pps
down.type DERIVE
down.min 0
up.label pps
up.type DERIVE
up.min 0
down.graph no
up.negative down
EOF
			;;
		*)
			echo "unknown mode '${1}'" >&2
			exit 1
			;;
	esac
}

fetch () {
	case "${1}" in
		"uptime")
		echo "${DATA}" | sed -n "s/.*uptime=\([0-9]\+\)s.*/uptime.value \1/p"
			;;
		"bitrate")
		echo "${DATA}" | sed -n "s/^MaxBitRateDown : \([0-9]\+\) bps.*MaxBitRateUp \([0-9]\+\) bps.*/down.value \1\nup.value \2/p"
			;;
		"traffic")
		echo "${DATA}" | sed -n "
		s/^Bytes:\s*Sent:\s*\([0-9]\+\).*Recv:\s*\([0-9]\+\).*/up.value \1\ndown.value \2/p"
		if [ "${traffic_remove_max:-false}" != 'true' ]; then
			echo "${DATA}" | sed -n "
			s/^MaxBitRateDown : \([0-9]\+\) bps.*MaxBitRateUp \([0-9]\+\) bps.*/maxdown.value \1\nmaxup.value \2/p"
		fi
			;;
		"pkts")
		echo "${DATA}" | sed -n "s/^Packets:\s*Sent:\s*\([0-9]\+\).*Recv:\s*\([0-9]\+\).*/up.value \1\ndown.value \2/p"
			;;
		*)
			echo "unknown mode '${1}'" >&2
			exit 1
			;;
	esac
}

case ${1:-} in
	"autoconf")
		autoconf
		;;
	"suggest")
		suggest
		;;
	"config")
		config "${MODE}"
		if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then
			fetch "${MODE}"
		fi
		;;
	*)
		fetch "${MODE}"
		;;
esac