#!/bin/bash

#
# monitor process resources using systat (/proc), free, iptables and /sys
#
# 2010, Razvan Deaconescu, razvan.deaconescu@cs.pub.ro
#

# command line argument must be a process id
if test $# -ne 1; then
	echo "Usage: $0 <pid>" 1>&2
	exit 1
fi

pid=$1

# check if pid exists
kill -0 $pid > /dev/null 2>&1
if test $? -ne 0; then
	echo -e "PID $pid does not exists.\nUsage: $0 <pid>" 1>&2
	exit 1
fi

# use _DEBUG="off" to turn off debug printing
_DEBUG="off"

# cleanup code (run as signal handler)
cleanup()
{
	kill -TERM $pidstat_pid
	kill -TERM $iostat_pid
	kill -TERM $free_pid
	kill -TERM $timer_callback_pid
}

# function acting like a periodic callback
timer_callback()
{
	while true; do
		date +%F-%X
		sudo iptables -t filter -L -n -v
		cat /sys/class/net/eth0/statistics/rx_bytes /sys/class/net/eth0/statistics/tx_bytes
		sleep 1
	done
}

# run cleanup on signal receive
trap cleanup 0 1 2 3 15

# per-process processor (-u), disk (-d) and memory usage (-r)
pidstat -u -d -r -p $pid 1 &
pidstat_pid=$!

# per-system (iostat and free)
iostat -d -c 1 &
iostat_pid=$!
free -s 1 &
free_pid=$!

# per-process network bandwidth usage (iptables)
# /sys/class/net/$iface/statistics/{tx,rx}_bytes (per system)

# remove old iptables rules/chains
sudo iptables -t filter -F udp_out > /dev/null 2>&1
sudo iptables -t filter -F udp_in > /dev/null 2>&1
sudo iptables -t filter -X udp_out > /dev/null 2>&1
sudo iptables -t filter -X udp_in > /dev/null 2>&1
sudo iptables -t filter -F OUTPUT > /dev/null 2>&1
sudo iptables -t filter -F INPUT > /dev/null 2>&1

# add iptables rule
sudo iptables -t filter -N udp_out
sudo iptables -t filter -N udp_in
sudo iptables -t filter -A OUTPUT -p udp -o br0 -j udp_out
sudo iptables -t filter -A udp_out -j ACCEPT
sudo iptables -t filter -A INPUT -p udp -i br0 -j udp_in
sudo iptables -t filter -A udp_in -j ACCEPT

timer_callback &
timer_callback_pid=$!

# wait for child processes to end (shouldn't happen)
wait