#!@@PERL@@ -w
# -*- perl -*-

=head1 NAME

snmp__df - Plugin to check disk usage of a remote host via SNMP

=head1 CONFIGURATION

The following environment variables are used

 host      - SNMP hostname to probe (default undef)
 port      - SNMP port to use (default 161)
 community - SNMP community string (default "public")
 interface - (default undef)

=head1 AUTHOR

Copyright (C) 2004 Jimmy Olsen

=head1 LICENSE

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; version 2 dated June,
1991.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

=head1 MAGIC MARKERS

 #%# family=snmpauto
 #%# capabilities=snmpconf

=head1 BUGS

The "interface" environment variable does not seem to be used in this
script.

=cut

use strict;
use Net::SNMP;

my $MAXLABEL = 20;

my $host      = $ENV{host}      || undef;
my $port      = $ENV{port}      || 161;
my $community = $ENV{community} || "public";
my $iface     = $ENV{interface} || undef;

my $response;

if (defined $ARGV[0] and $ARGV[0] eq "snmpconf")
{
	print "require 1.3.6.1.2.1.25.2.3.1.1.\n";
	print "require 1.3.6.1.2.1.25.2.3.1.2. 1.3.6.1.2.1.25.2.1.4\n"; # Type=fixed disk
	print "require 1.3.6.1.2.1.25.2.3.1.5. [1-9]\n"; # Size > 0
	exit 0;
}

if ($0 =~ /^(?:|.*\/)snmp_([^_]+)_df$/)
{
	$host  = $1;
	if ($host =~ /^([^:]+):(\d+)$/)
	{
		$host = $1;
		$port = $2;
	}
}
elsif (!defined($host))
{
	print "# Debug: $0 -- $1\n" if $Munin::Plugin::SNMP::DEBUG;
	die "# Error: couldn't understand what I'm supposed to monitor.";
}

# Partition level
my $hrFSIndex              = "1.3.6.1.2.1.25.3.8.1.1."; # Should be more than 0
my $hrFSMountPoint         = "1.3.6.1.2.1.25.3.8.1.2."; # Used to look up filesystem

# Filesystem level
my $hrStorageType          = "1.3.6.1.2.1.25.2.3.1.2."; # Backup for hrFS*
my $hrStorageDesc          = "1.3.6.1.2.1.25.2.3.1.3."; # Used as key from partitions
my $hrStorageSize          = "1.3.6.1.2.1.25.2.3.1.5."; # Data point 1
my $hrStorageUsed          = "1.3.6.1.2.1.25.2.3.1.6."; # Data point 2


my ($session, $error) = Net::SNMP->session(
		-hostname  => $host,
		-community => $community,
		-port      => $port
	);

if (!defined ($session))
{
	die "Croaking: $error";
}
# Take a look at the partitions...

my %partitions;

my $parts = get_by_regex ($session, $hrFSIndex, "[1-9]");

foreach my $partition (keys %$parts)
{
    my $mp = get_single ($session, $hrFSMountPoint . $partition);
    $partitions{$mp}{partition} = $partition;
    print "# Added partition \"$mp\" as $partition...\n" if $Munin::Plugin::SNMP::DEBUG;
}

my $stor_id;

my $foundpartitions = keys %partitions;

if ($foundpartitions == 0 or defined $partitions{""})
{ # Oh bugger. Some (or all) mountpoints were undeterminable. The backup
  # solution is to just graph everything that claims to be a FixedDisk,
  # without checking if it's removable etc

    	print "# Unable to map mountpoints from filesystems to storages. Bugger.\n" if $Munin::Plugin::SNMP::DEBUG;
	$stor_id = get_by_regex ($session, $hrStorageType, "1.3.6.1.2.1.25.2.1.4");
	%partitions = ();

	foreach my $id (keys %$stor_id)
	{
		my $part = get_single ($session, $hrStorageDesc . $id);
		my $spart = $part;
		$spart =~ s/:\\ Label:.*/:/;
		$partitions{$spart}{storage} = $id;
		$partitions{$spart}{extinfo} = $part;
		$stor_id->{$id} = $spart;
	}
} else 
{ # Get the ones we're sure are really fixed

	$stor_id   = get_by_regex ($session, $hrStorageDesc, '(^'.join('$|^',keys(%partitions)).'$)');
}

foreach my $storage (keys %$stor_id)
{
    $partitions{$stor_id->{$storage}}{storage} = $storage;
    $partitions{$stor_id->{$storage}}{size}    = get_single ($session, $hrStorageSize . $storage);
    if ($partitions{$stor_id->{$storage}}{size} == 0) {
      delete $stor_id->{$storage} ;
    }
}

foreach my $part (keys %partitions)
{
    if ($partitions{$part}{size} == 0) { delete $partitions{$part} ; }
}

if (defined $ARGV[0] and $ARGV[0] eq "config")
{
	print "host_name $host\n" unless $host eq 'localhost';
	print "graph_title Disk usage in percent\n";
	print "graph_args --upper-limit 100 -l 0\n";
	print "graph_vlabel %\n";
	print "graph_category disk\n";
	print "graph_info This graph shows partition usage in percent.\n";

	foreach my $part (keys %partitions)
	{
		print (&get_name_by_mp ($part), ".label ");
		print (length($part)<=$MAXLABEL ? $part : "...".substr($part,-($MAXLABEL-3)));
		print ("\n");
		print (&get_name_by_mp ($part), ".warning 92\n");
		print (&get_name_by_mp ($part), ".critical 98\n");
		print (&get_name_by_mp ($part), ".info Usage for ". ($partitions{$part}{extinfo}||$part)."\n");
	}
	exit 0;
}

foreach my $storage (keys %$stor_id)
{
    $partitions{$stor_id->{$storage}}{used}    = get_single ($session, $hrStorageUsed . $storage);
}

foreach my $part (keys %partitions)
{
    print (&get_name_by_mp ($part), ".value ", ($partitions{$part}{used}*100/$partitions{$part}{size}), "\n");
}

sub get_single
{
	my $handle = shift;
	my $oid    = shift;

	print "# Getting single $oid..." if $Munin::Plugin::SNMP::DEBUG;

	$response = $handle->get_request ($oid);

	if (!defined $response->{$oid})
	{
	    print "undef\n" if $Munin::Plugin::SNMP::DEBUG;
	    return undef;
	}
	else
	{
	    print "\"$response->{$oid}\"\n" if $Munin::Plugin::SNMP::DEBUG;
	    return $response->{$oid};
	}
}

sub get_by_regex
{
	my $handle = shift;
	my $oid    = shift;
	my $regex  = shift;
	my $result = {};
	my $num    = 0;
	my $ret    = $oid . "0";
	my $response;

	print "# Starting browse of $oid...\n" if $Munin::Plugin::SNMP::DEBUG;

	while (1)
	{
		if ($num == 0)
		{
			print "# Checking for $ret...\n" if $Munin::Plugin::SNMP::DEBUG;
			$response = $handle->get_request ($ret);
		}
		if ($num or !defined $response)
		{
			print "# Checking for sibling of $ret...\n" if $Munin::Plugin::SNMP::DEBUG;
			$response = $handle->get_next_request ($ret);
		}
		if (!$response)
		{
			return undef;
		}
		my @keys = keys %$response;
		$ret = $keys[0];
		print "# Analyzing $ret (compared to $oid)...\n" if $Munin::Plugin::SNMP::DEBUG;
		last unless ($ret =~ /^$oid/);
		$num++;
		next unless ($response->{$ret} =~ /$regex/);
		@keys = split (/\./, $ret);
		$result->{$keys[-1]} = $response->{$ret};;
		print "# Index $num: ", $keys[-1], " (", $response->{$ret}, ")\n" if $Munin::Plugin::SNMP::DEBUG;
	};
	return $result;
}

sub get_name_by_mp
{
    my $mp = shift;
    $mp =~ s/[^a-z0-9_]/_/gi;
    $mp =~ tr/A-Z/a-z/;
    return "p" . $mp;
}
