wireless_channel_occupation_: move from "network" to "wifi"

plugins/wifi/wireless_channel_occupation_

@@ -0,0 +1,143 @@
+#!/bin/sh
+
+: << =cut
+
+=head1 NAME
+
+wireless_channel_occupation_ - Monitor occupation of wireless channels
+
+
+=head1 APPLICABLE SYSTEMS
+
+All systems with at least one wireless interface and the the tool "iw".
+
+The wifi channel occupation is parsed from the output of "iw dev wlan0 survey dump".
+
+
+=head1 CONFIGURATION
+
+Symlink this plugin with the name of the wifi interface added (e.g. "wlan0").
+
+Root permissions are probably required for accessing "iw".
+
+  [wireless_channel_occupation_*]
+  user root
+
+
+=head1 VERSION
+
+  1.1
+
+
+=head1 AUTHOR
+
+Lars Kruse <devel@sumpfralle.de>
+
+
+=head1 LICENSE
+
+GPLv3 or above
+
+
+=head1 MAGIC MARKERS
+
+  #%# family=auto
+  #%# capabilities=autoconf suggest
+
+=cut
+
+set -eu
+
+
+SCRIPT_PREFIX="wireless_channel_occupation_"
+
+
+clean_fieldname() {
+	echo "$1" | sed 's/^\([^A-Za-z_]\)/_\1/; s/[^A-Za-z0-9_]/_/g'
+}
+
+
+get_wifi_interfaces() {
+	iw dev | grep Interface | awk '{print $2}'
+}
+
+get_wifi_device_from_suffix() {
+	local suffix
+	local real_dev
+	# pick the part after the basename of the real file
+	suffix=$(basename "$0" | sed "s/^$SCRIPT_PREFIX//")
+	for real_dev in $(get_wifi_interfaces); do
+		[ "$suffix" != "$(clean_fieldname "$real_dev")" ] || echo "$real_dev"
+	done | head -1
+}
+
+
+do_config() {
+	local device
+	local dev_field
+	device=$(get_wifi_device_from_suffix)
+	[ -z "$device" ] && echo >&2 "Invalid wifi device name given" && return 1
+	echo "graph_title Channel Occupation of $device"
+	echo "graph_vlabel %"
+	echo "graph_category wireless"
+	echo "graph_args --base 1000 -r --lower-limit 0 --upper-limit 100"
+	dev_field=$(clean_fieldname "$device")
+
+	# active: listening time on this channel (usually: 5 minutes = 300000ms)
+	echo "${dev_field}_active.label Transmit"
+	echo "${dev_field}_active.type DERIVE"
+	echo "${dev_field}_active.graph no"
+
+	# busy = receive + transmit + unknown
+	echo "${dev_field}_busy.label unknown"
+	echo "${dev_field}_busy.type DERIVE"
+	echo "${dev_field}_busy.draw AREA"
+	echo "${dev_field}_busy.cdef 100,1,${dev_field}_active,${dev_field}_busy,${dev_field}_receive,${dev_field}_transmit,+,-,/,/,*"
+
+	# receive: this radio receives traffic for itself
+	echo "${dev_field}_receive.label Receive"
+	echo "${dev_field}_receive.type DERIVE"
+	echo "${dev_field}_receive.draw STACK"
+	echo "${dev_field}_receive.cdef 100,${dev_field}_receive,${dev_field}_active,/,*"
+
+	# transmit: this radio transmits traffic
+	echo "${dev_field}_transmit.label Transmit"
+	echo "${dev_field}_transmit.type DERIVE"
+	echo "${dev_field}_transmit.draw STACK"
+	echo "${dev_field}_transmit.cdef 100,${dev_field}_transmit,${dev_field}_active,/,*"
+}
+
+
+do_fetch() {
+	local device
+	device=$(get_wifi_device_from_suffix)
+	[ -z "$device" ] && echo >&2 "Invalid wifi device name given" && return 1
+	iw dev "$device" survey dump \
+		| grep -F -A 5 "[in use]" \
+		| grep -E "channel (busy|receive|transmit|active) time:" \
+		| awk '{print "'"${device}_"'"$2"'.value'",$4}'
+}
+
+
+if [ "${1:-}" = "autoconf" ]; then
+	if which iw >/dev/null; then
+		if [ -n "$(get_wifi_interfaces)" ]; then
+			echo "yes"
+		else
+			echo "no (missing wifi devices)"
+		fi
+	else
+		echo "no (missing 'iw' dependency)"
+	fi
+elif [ "${1:-}" = "suggest" ]; then
+	for dev in $(get_wifi_interfaces); do
+		clean_fieldname "$dev"
+	done
+elif [ "${1:-}" = "config" ]; then
+	do_config || exit 1
+	[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] && do_fetch
+else
+	do_fetch
+fi
+
+exit 0