#!/usr/bin/perl

use strict;
use FileHandle;
use RRDs;
use Glib;
my $debug	= 0;
my $host	= "loke";
my @eth		= &gather_eth;
my @outfile;
my $loop	= Glib::MainLoop->new;
my $timer	= Glib::Timeout	-> add(10000, \&update_all);

$loop -> run;

sub update_all
{
	my $i	= 0;
	while($i < scalar(@eth))
	{
		die "WTF??" if($eth[$i] eq '');
		&debug("Found nic $eth[$i]\n");
		&debug("Setting rrd-file to /var/www/apps/etherstats/$host/$eth[$i].rrd\n");
		$outfile[$i] = "/var/www/apps/etherstats/$host/$eth[$i].rrd";
		&update($outfile[$i],$eth[$i]);
		$i++;
	}
	return 1;
}

sub create
{
	my $of		= $_[0];
	RRDs::create(	"$of",
			"-s 10",
			'DS:bytesIn:COUNTER:20:0:U',
			'DS:bytesOut:COUNTER:20:0:U',
			'RRA:AVERAGE:0.5:1:360',
			'RRA:AVERAGE:0.5:6:1440',
			'RRA:AVERAGE:0.5:30:2014',
			'RRA:AVERAGE:0.5:360:672',
			'RRA:AVERAGE:0.5:8640:365',
			);
	&errorcheck;
	`chmod 640 "$of"`;
	`chown admin:www-data "$of"`;
	&debug("rrd-file $of created\n");
}

sub update
{
	my $of		= $_[0];
	my $if		= $_[1];
	if($if eq 'lo')
	{
		&debug("Ignoring loopback-device\n");
		return 1;
	}
	unless( -e $of)
	{
		&create($of);
	}
	if( -e $of)
	{
		&debug("Updating stats for $if in $of..\n");
		my ($in,$out)	= split(',',&gather($if));
		my $now		= time;
		RRDs::update(	"$of",
				"$now:$in:$out"
				);
		&errorcheck;
	}
	return 1;
}

sub gather_eth
{
	my @return;
	if(-e "/sys/class/net/")
	{
		&debug("/sys/class/net/ found\n");
		open(ETH,"ls -1 /sys/class/net/|");
		for (;;)
		{
			undef $!;
			my $line;
			unless(defined( $line = <ETH> ))
			{
				print $! if $!;
				last; # EOF
			}
			else
			{
				chomp($line);
				&debug("Interface $line found\n");
				push(@return,$line);
			}
		}
		close(ETH);
		return @return;
	}
	else
	{
		print "No /sys/class/net? Either no network cards, or no sysfs mounted..\n";
	}
}

sub gather
{
	my $if		= $_[0];
	if(defined($if))
	{
		if(-e "/sys/class/net/$if/statistics/")
		{
			&debug("	statistics found in /sys/class/net/$if/statistics/\n");
			my ($inbytes,$outbytes,$line);
			open(IN,"/sys/class/net/$if/statistics/rx_bytes");
			for (;;)
			{
				undef $!;
				undef($line);
				unless(defined( $line = <IN> ))
				{
					print $! if $!;
					last; # EOF
				}
				else
				{
					$inbytes = $line;
				}
			}
			close(IN);
			open(OUT,"/sys/class/net/$if/statistics/tx_bytes");
			for (;;)
			{
				undef $!;
				unless(defined( $line = <OUT> ))
				{
					print $! if $!;
					last; # EOF
				}
				else
				{
					$outbytes = $line;
				}
			}
			close(OUT);
			chomp($inbytes);
			chomp($outbytes);
			&debug("	In : $inbytes\n	Out : $outbytes\n");
			return "$inbytes,$outbytes";
		}
	}
	return 1;
}

sub errorcheck
{
	my $ERR	= RRDs::error;
	print "$ERR\n" if defined($ERR);
}

sub debug
{
	if($debug == 1)
	{
		print $_[0];
	}
}