2
0
mirror of https://github.com/munin-monitoring/contrib.git synced 2018-11-08 00:59:34 +01:00
contrib-munin/plugins/wifi/wireless_signal_noise_
Lars Kruse c81c20ab3b unify DIRTYCONFIG handling in shell and python plugins
The following issues were fixed:
* comparison too broad (e.g. "0" misinterpreted as "true")
* python: comparing string with number (is never equal in python)
* unwanted non-zero exitcode (compound command "&&" as last command in
  shell code block (e.g. "case" or "if" branch))
* access to unset variable (shell style issue)
2018-04-07 02:17:06 +02:00

173 lines
4.1 KiB
Bash
Executable File

#!/bin/sh
: << =cut
=head1 NAME
wireless_signal_noise_ - Show signal strength and noise for all connected peers of wifi interface
=head1 APPLICABLE SYSTEMS
This plugin is suitable for wifi interfaces with a stable selection of peers (e.g. infrastructure).
It is probably not useful for hotspot-like scenarios.
Information is parsed from the output of the tool "iwinfo" (OpenWrt) or "iw" (most systems,
incomplete information).
=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_signal_noise_*]
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_signal_noise_"
# prefer "iwinfo" for information retrieval, if it is available
if which iwinfo >/dev/null; then
# "iwinfo" has a stable output format but is only available on openwrt
get_wifi_interfaces() { iwinfo | grep "^[a-zA-Z]" | awk '{print $1}'; }
# return MAC of peer and the signal strength
get_wifi_peers() { iwinfo "$1" assoclist | grep "^[0-9a-fA-F]" | awk '{print $1,$2}'; }
# the noise should be the same for all peers
get_wifi_noise() { iwinfo "$1" info | sed -n 's/^.* Noise: \([0-9-]\+\).*/\1/p'; }
else
# "iw" is available everywhere - but its output format is not recommended for non-humans
get_wifi_interfaces() { iw dev | awk '{ if ($1 == "Interface") print $2; }'; }
get_wifi_peers() { iw dev wlan0 station dump \
| awk '{ if ($1 == "Station") mac=$2; if (($1 == "signal") && ($2 == "avg:")) print mac,$3}'; }
# TODO: there seems to be no way to retrieve the noise level via "iw"
get_wifi_noise() { echo; }
fi
if which arp >/dev/null; then
# openwrt does not provide 'arp' by default
get_arp() { arp -n; }
else
get_arp() { cat /proc/net/arp; }
fi
clean_fieldname() {
echo "$1" | sed 's/^\([^A-Za-z_]\)/_\1/; s/[^A-Za-z0-9_]/_/g'
}
get_ip_for_mac() {
local ip
ip=$(get_arp | grep -iw "$1$" | awk '{print $1}' | sort | head -1)
[ -n "$ip" ] && echo "$ip" && return 0
# no IP found - return MAC instead
echo "$1"
}
get_wifi_device_from_suffix() {
local suffix
local real_dev
# pick the part after the basename of the real file
suffix=$(basename "$0" | sed "s/^$SCRIPT_PREFIX//")
for real_dev in $(get_wifi_interfaces); do
[ "$suffix" != "$(clean_fieldname "$real_dev")" ] || echo "$real_dev"
done | head -1
}
do_config() {
local wifi
wifi=$(get_wifi_device_from_suffix)
[ -z "$wifi" ] && echo >&2 "Missing wifi: $wifi" && return 1
echo "graph_title Wireless signal quality - $wifi"
echo "graph_args --upper-limit 0"
echo "graph_vlabel Signal and noise [dBm]"
echo "graph_category network"
echo "graph_info This graph shows the signal and noise for all wifi peers"
echo "noise.label Noise floor"
echo "noise.draw LINE"
# sub graphs for all peers
get_wifi_peers "$wifi" | while read -r mac signal; do
fieldname=$(clean_fieldname "peer_${mac}")
peer=$(get_ip_for_mac "$mac")
echo "signal_${fieldname}.label $peer"
echo "signal_${fieldname}.draw LINE"
done
}
do_fetch() {
local wifi
local peer_data
local noise
wifi=$(get_wifi_device_from_suffix)
[ -z "$wifi" ] && echo >&2 "Missing wifi: $wifi" && return 1
peer_data=$(get_wifi_peers "$wifi")
echo "$peer_data" | while read -r mac signal; do
# ignore empty datasets
[ -z "$signal" ] && continue
fieldname=$(clean_fieldname "peer_${mac}")
echo "signal_${fieldname}.value $signal"
done
noise=$(get_wifi_noise "$wifi")
echo "noise.value ${noise:-U}"
}
ACTION="${1:-}"
case "$ACTION" in
config)
do_config || exit 1
if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
;;
autoconf)
if [ -z "$(get_wifi_interfaces)" ]; then
echo "no (no wifi interfaces found)"
else
echo "yes"
fi
;;
suggest)
get_wifi_interfaces | while read -r ifname; do
clean_fieldname "$ifname"
done
;;
"")
do_fetch
;;
*)
echo >&2 "Invalid action (valid: config / suggest / autoconf / <empty>)"
echo >&2
exit 2
;;
esac