#!/usr/bin/perl
# 
# This tool watches for network changes and updates a cache file when changes are found.
# 
# NOTE: This tool does NOT connect to the databases. This is meant to be as quick as possible and to use as 
#       few resources as possible. It will exit with 'ok' or 'change' depending on if something in the 
#       network changed.
#
# Exit codes;
# 0 = Normal exit
# 
# TODO: 
# - 
# 

use strict;
use warnings;
use Time::HiRes qw(gettimeofday tv_interval);
my $start_time = [gettimeofday];
use Anvil::Tools;

my $THIS_FILE           =  ($0 =~ /^.*\/(.*)$/)[0];
my $running_directory   =  ($0 =~ /^(.*?)\/$THIS_FILE$/)[0];
if (($running_directory =~ /^\./) && ($ENV{PWD}))
{
	$running_directory =~ s/^\./$ENV{PWD}/;
}

# Turn off buffering so that the pinwheel will display while waiting for the SSH call(s) to complete.
$| = 1;

my $anvil = Anvil::Tools->new();
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 3, secure => 0, key => "log_0115", variables => { program => $THIS_FILE }});

scan($anvil);

my $total = tv_interval ($start_time, [gettimeofday]);
print "Total runtime: [".$total."]\n";
$anvil->nice_exit({exit_code => 0});


#############################################################################################################
# Functions                                                                                                 #
#############################################################################################################

sub scan
{
	my ($anvil) = @_;
	
	my $directory = "/sys/class/net";
	print $THIS_FILE." ".__LINE__."; directory: [".$directory."]\n";
	local(*DIRECTORY);
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 3, key => "log_0018", variables => { directory => $directory }});
	opendir(DIRECTORY, $directory);
	while(my $file = readdir(DIRECTORY))
	{
		next if $file eq ".";
		next if $file eq "..";
		next if $file eq "lo";
		my $full_path = "$directory/$file";
		print $THIS_FILE." ".__LINE__."; full_path: [".$full_path."]\n";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { full_path => $full_path }});
		if (-d $full_path)
		{
			# Pull out the data I want. Note that some of these don't exist with virtio-net interfaces.
			my $interface   = $file;
			my $mac_address = -e $full_path."/address"   ? $anvil->Storage->read_file({file => $full_path."/address"})   : "";
			my $link_state  = -e $full_path."/carrier"   ? $anvil->Storage->read_file({file => $full_path."/carrier"})   : 0;
			my $mtu         = -e $full_path."/mtu"       ? $anvil->Storage->read_file({file => $full_path."/mtu"})       : 0;
			my $duplex      = -e $full_path."/duplex"    ? $anvil->Storage->read_file({file => $full_path."/duplex"})    : "unknown";	# full or half?
			my $operational = -e $full_path."/operstate" ? $anvil->Storage->read_file({file => $full_path."/operstate"}) : "unknown";	# up or down
			my $speed       = $link_state ? $anvil->Storage->read_file({file => $full_path."/speed"}) : 0;	# Mbps (ie: 1000 = Gbps), gives a very high number for unplugged link
			if ($speed > 100000)
			{
				# NOTE: This is probably 0 now... Though someday >100 Gbps will be reasonable
				#       and we'll need to change this.
				$speed = 0;
			}
			
			# Find the media, if possible.
			my $media      = "unknown";
			my $shell_call = $anvil->data->{path}{exe}{ethtool}." $interface";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { shell_call => $shell_call }});
			my $ethtool    = $anvil->System->call({shell_call => $shell_call});
			foreach my $line (split/\n/, $ethtool)
			{
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { line => $line }});
				if ($line =~ /Supported ports: \[ (.*?) \]/i)
				{
					$media = lc($1);
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { media => $media }});
					last;
				}
			}
			
			# Log
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
				interface   => $interface, 
				mac_address => $mac_address, 
				link_state  => $link_state, 
				mtu         => $mtu, 
				duplex      => $duplex,
				operational => $operational,
				speed       => $speed,
				media       => $media, 
			}});
		}
	}
	closedir(DIRECTORY);
	
	return(0);
}