#!/bin/sh

# Copyright 2015-2020 Rivoreo

# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:

# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE
# FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

if [ -z "${PROGRAM_DIR+set}" ]; then
	echo "You should not run this script directly" 1>&2
	exit 255
fi

[ -n "$LINPROCFS" ] && [ -f "$LINPROCFS/net/dev" ] && proc_net_dev_file="$LINPROCFS/net/dev" || proc_net_dev_file=/proc/net/dev
last_interfaces=
interfaces=
while true; do
	line_count=0
	while read line; do
		line_count=$((line_count+1))
		[ $line_count -lt 3 ] && continue
		set -- $line
		if [ $# != 17 ]; then
			echo "data error: # $# != 17" 1>&2
			continue
		fi
		ifname="${1%:}"
		[ "$ifname" = lo ] && continue
		e_ifname="`printf %s \"$ifname\" | sed -r 's/[.-]/_/g'`"
		interfaces="$interfaces $e_ifname"
		eval "last_rx=\$last_rx_$e_ifname"
		eval "last_tx=\$last_tx_$e_ifname"
		if [ -n "$last_rx" ] && [ -n "$last_tx" ]; then
			rx_diff=$((${2}-last_rx))
			tx_diff=$((${10}-last_tx))
			[ "$rx_diff" -lt 0 ] && rx_diff=0
			[ "$tx_diff" -lt 0 ] && tx_diff=0
			if [ $INTERVAL -gt 1 ]; then
				rx_diff=$((rx_diff/INTERVAL))
				tx_diff=$((tx_diff/INTERVAL))
			fi
			if [ -n "$INFLUXDB_BASE_URL" ]; then
				http_post "${INFLUXDB_BASE_URL}write?db=$INFLUXDB_DB_NAME" \
					"traffic,host=$HOSTNAME,interface=$ifname receive_rate=$rx_diff,transmit_rate=$tx_diff" 1>&2
			fi
			if [ -n "$CARBON_SERVER" ]; then
				printf '%s\n%s\n' \
					"traffic.$HOSTNAME.$ifname.receive_rate $rx_diff -1" \
					"traffic.$HOSTNAME.$ifname.transmit_rate $tx_diff -1"
			fi
		fi
		eval "last_rx_$e_ifname=${2}"
		eval "last_tx_$e_ifname=${10}"
	done < "$proc_net_dev_file"
	for oi in $last_interfaces; do
		for i in $interfaces; do
			[ $i = $oi ] && continue 2
		done
		unset last_rx_$oi last_tx_$oi
	done
	last_interfaces="$interfaces"
	interfaces=
	sleep $INTERVAL
done | send_carbon_lines
