#!/usr/bin/perl -w
# -*- perl -*-

=head1 NAME

if - Multigraph plugin to monitor network wired and wireless interfaces

=head1 INTERPRETATION

In the general graphs made key fields for each interface, a subsidiary graphs for each interface there are detailed

This plugin displays the following charts:
Traffic, bit
Traffic, packets
Average packet size
Interface errors
WiFi interface errors
WiFi interface signal and noise
WiFi interface link quality
Interface utilisation

Virtual interface names prefixes with '~'

=head1 CONFIGURATION

This plugin is configurable environment variables.
env.exclude         - Removing interfaces from graphs, default empty
env.include         - Includes interfaces into graphs, default empty
env.if_max_bps      - Maximum interface bps. Available suffixes: k, M, G, default empty
env.protexct_peaks  - Protect graph peaks, default 'no'
env.min_packet_size - Minimal network packet size, default 20
Example:
 [if]
    env.exclude lo
    env.include wlan0 tun0
    env.wlan0_max_bps 54M
    env.eth0_max_bps 1G
    env.protect_peaks yes

Protect peak:
1. Protect wifi signal and noise values, all values > 0 print as NaN
2. protect all percent values. All values > 100 print as NaN
3. Protect bps values. env.if_max_bps must be set. All values > max_bps prints as 0
4. protect pps values. env.if_max_bps must be set. All values > max_bps/minimal packet size, prints as 0

=head1 AUTHOR

Gorlow Maxim aka Sheridan <sheridan@sheridan-home.ru> (email and jabber)

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

  #%# family=auto
  #%# capabilities=autoconf

=cut

use strict;
use warnings;
use IO::Dir;
use Munin::Plugin;
use Data::Dumper;

# ------------------------------------------------------------- constants ---------------------
my $exclude         = $ENV{exclude}         || '';
my $include         = $ENV{include}         || '-';
my $protect_peacks  = $ENV{protect_peaks}   || 'no';
my $min_packet_size = $ENV{min_packet_size} || 20;
my $ifpath          = '/sys/class/net';
# ----------------------------------- global -----------------
my $interfaces = {};

# ------------------------ available graphs -------------------------
my $graphs =
{
  'if_bit' =>
  {
    'munin' =>
    {
      'category' => 'network',
      'args'     => '--base 1000',
      'title'    => ':if: traffic, bit',
      'vlabel'   => 'Bit in (-) / out (+), avg. per second',
      'info'     => 'This graph shows the traffic in bit of the :if:, averaged value per second from last update'
    },
    'per_if_fields'  => [qw(rx_bytes tx_bytes)],
    'general_fields' => [qw(rx_bytes tx_bytes)]
  },
  'if_packets' =>
  {
    'munin' =>
    {
      'category' => 'network',
      'args'     => '--base 1000',
      'title'    => ':if: traffic, packets',
      'vlabel'   => 'Packets in (-) / out (+), avg. per second',
      'info'     => 'This graph shows the traffic in packets of the :if:, averaged value per second from last update'
    },
    'per_if_fields'  => [qw(rx_packets tx_packets rx_compressed tx_compressed rx_dropped tx_dropped multicast)],
    'general_fields' => [qw(rx_packets tx_packets)]
  },
  'if_errors' =>
  {
    'munin' =>
    {
      'category' => 'network',
      'args'     => '--base 1000',
      'title'    => ':if: errors',
      'vlabel'   => 'Errors RX (-) / TX (+)',
      'info'     => 'This graph shows the errors of the :if: from last update',
      'scale'    => 'no'
    },
    'per_if_fields'  => [qw(rx_errors tx_errors rx_fifo_errors tx_fifo_errors rx_crc_errors rx_frame_errors rx_length_errors rx_missed_errors rx_over_errors collisions tx_aborted_errors tx_carrier_errors tx_heartbeat_errors tx_window_errors)],
    'general_fields' => [qw(rx_errors tx_errors)]
  },
  'if_wifi_sino' =>
  {
    'munin' =>
    {
      'category' => 'wireless',
      'args'     => '--base 1000 -u 0',
      'title'    => ':if: signal and noise levels',
      'vlabel'   => 'dB',
      'info'     => 'This graph shows the WiFi signal and noise levels of the :if:',
      'scale'    => 'no'
    },
    'per_if_fields'  => [qw(signal noise)],
    'general_fields' => [qw(signal)]
  },
  'if_wifi_link_quality' =>
  {
    'munin' =>
    {
      'category' => 'wireless',
      'args'     => '--base 1000',
      'title'    => ':if: link quality',
      'vlabel'   => '%',
      'info'     => 'This graph shows the WiFi link quality of the :if:',
      'scale'    => 'no'
    },
    'per_if_fields'  => [qw(link)],
    'general_fields' => [qw(link)]
  },
  'if_wifi_errors' =>
  {
    'munin' =>
    {
      'category' => 'wireless',
      'args'     => '--base 1000',
      'title'    => ':if: errors',
      'vlabel'   => 'Errors RX (-) / TX (+)',
      'info'     => 'This graph shows the WiFi errors of the :if: from last update',
      'scale'    => 'no'
    },
    'per_if_fields'  => [qw(nwid fragment crypt beacon retries misc)],
    'general_fields' => [qw(rx_wifierr tx_wifierr)]
  },
  'if_utilisation' =>
  {
    'munin' =>
    {
      'category' => 'network',
      'args'     => '--base 1000',
      'title'    => ':if: utilisation',
      'vlabel'   => '%',
      'info'     => 'This graph shows utilisation of the :if:',
      'scale'    => 'no'
    },
    'per_if_fields'  => [qw(rx_percent tx_percent)],
    'general_fields' => [qw(rx_percent tx_percent)]
  },
  'if_avgpacketsize' =>
  {
    'munin' =>
    {
      'category' => 'network',
      'args'     => '--base 1024',
      'title'    => ':if: average packet size',
      'vlabel'   => 'bytes',
      'info'     => 'This graph shows average packet size of the :if:'
    },
    'per_if_fields'  => [qw(rx_size tx_size)],
    'general_fields' => [qw(rx_size tx_size)]
  }
};

#-------------------------- available fields -------------------------
# info:
# 'munin' => {} - just copy fields to munin config
# 'source' => - field data source
#    {
#      'type' =>  types:
#         'file' - data just cat from file
#           'location' => file location
#         'calculated' => calculated data
#         {
#            'type' - types:
#               'percent',
#                 'full' =>
#                 {
#                    'source' => 'interface',
#                    'name' => 'bps'
#                 },
#                 'part' =>
#                 {
#                   'source' => 'field',
#                   'name' => 'tx_bytes'
#                 }
#              'division',
#                'dividend' =>
#                {
#                  'source' => 'field',
#                  'name' => 'rx_bytes'
#                },
#                'divider' =>
#                {
#                  'source' => 'field',
#                  'name' => 'rx_packets'
#                }
#              'sum',
#                'sum' => [qw(nwid fragment crypt)]
#
#          }
#    }
# 'difference'    => difference types:
#     count      - just count from last update
#     per_secund - count from last update / time difference per last update
# 'negative' => - if field under zero line
#    {
#      'type' => types:
#        'dummy' - dummy field, not draw
#          'value' => '' - value for dummy field in update
#        'field' - exists field, must be included in graph
#          'name' => '' - field name
#    }
# 'peack_protect' => protect peaks. Using munin field.max and field.min and truncate data to NaN
#       protect types
#        'max_interface_bps'     - maximum: max interface bps (if configured), minimum - zero
#        'packet_size_range'     - maximum: mtu, minimum: minimal packet size (may be configured)
#        'max_interface_pps'     - maximum: max interface bps/minimum packt size (if configured), minimum - zero
#        'percents'              - maximum: 100, minimum: 0
#        'min_number:max_number' - no comments :)
my $fields =
{
  'collisions' =>
  {
    'munin' =>
    {
      'label' => 'Collisions'         ,
      'info'  => 'Transmit collisions',
      'type'  => 'GAUGE',
      'draw'  => 'LINE1'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/collisions'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'multicast' =>
  {
    'munin' =>
    {
     'type'  => 'GAUGE',
     'draw'  => 'LINE1',
     'label' => 'Multicast packets',
     'info'  => 'Multicast packets received'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/multicast'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference'    => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'rx_bytes' =>
  {
    'munin' =>
    {
     'type'  => 'GAUGE',
     'draw'  => 'LINE1',
     'label' => 'RX bit',
     'info'  => 'RX bit'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_bytes'
    },
    'cdef' => '8,*',
    'peack_protect' => 'max_interface_bps',
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_bytes'
    },
    'difference' => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'rx_compressed' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX compressed packets',
      'info'  => 'Compressed packets',
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_compressed'
    },
    'peack_protect' => 'max_interface_pps',
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_compressed'
    },
    'difference' => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'rx_crc_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'CRC errors' ,
      'info'  => 'CRC errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_crc_errors'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_dropped' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX dropped packets',
      'info'  => 'Dropped frames'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_dropped'
    },
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_dropped'
    },
    'difference' => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'rx_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX errors',
      'info'  => 'Bad packets'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_errors'
    },
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_fifo_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX FIFO errors',
      'info'  => 'FIFO overrun errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_fifo_errors'
    },
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_fifo_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_frame_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Frame format errors',
      'info'  => 'Frame format errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_frame_errors'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_length_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Length errors',
      'info'  => 'Length errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_length_errors'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_missed_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Missed packetss',
      'info'  => 'Missed packets'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_missed_errors'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_over_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Overrun errors',
      'info'  => 'Overrun errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_over_errors'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_packets' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX packets',
      'info'  => 'RX packets'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/rx_packets'
    },
    'peack_protect' => 'max_interface_pps',
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_packets'
    },
    'difference' => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'tx_aborted_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Aborted frames',
      'info'  => 'Aborted frames'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_aborted_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'tx_bytes' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX bit',
      'info'  => 'TX bit'
    },
    'source' =>
    {
      'type' => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_bytes'
    },
    'cdef' => '8,*',
    'peack_protect'  => 'max_interface_bps',
    'difference'     => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'tx_carrier_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Carrier errors',
      'info'  => 'Carrier errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_carrier_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'tx_compressed' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX compressed packets',
      'info'  => 'Compressed packets'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_compressed'
    },
    'peack_protect' => 'max_interface_pps',
    'difference'    => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'tx_dropped' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX dropped packets',
      'info'  => 'Dropped frames'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_dropped'
    },
    'difference' => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'tx_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX errors',
      'info'  => 'Transmit problems'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'tx_fifo_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX FIFO errors',
      'info'  => 'FIFO errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_fifo_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'tx_heartbeat_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Heartbeat errors',
      'info'  => 'Heartbeat errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_heartbeat_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'tx_packets' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX packets',
      'info'  => 'TX packets'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_packets'
    },
    'peack_protect' => 'max_interface_pps',
    'difference'    => 'per_secund'
  },
  # --------------------------------------------------------------------------
  'tx_window_errors' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Window errors',
      'info'  => 'Window errors'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/statistics/tx_window_errors'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'signal' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Signal level',
      'info'  => 'WiFi signal level'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/level',
      'prepare'  => ':data:=:data:-256'
    },
#    'cdef'  => '-256,+',
    'peack_protect'  => '-256:0'
  },
  # --------------------------------------------------------------------------
  'noise' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Noise level',
      'info'  => 'WiFi noise level'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/noise',
      'prepare'  => ':data:=:data:-256'
    },
#    'cdef'  => '-256,+',
    'peack_protect' => '-256:0'
  },
  # --------------------------------------------------------------------------
  'link' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Signal quality',
      'info'  => 'WiFi signal quality'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/link'
    },
    'peack_protect' => 'percent'
  },
  # --------------------------------------------------------------------------
  'rx_percent' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX Utilisation',
      'info'  => 'RX utilisation'
    },
    'source' =>
    {
      'type' => 'calculated',
      'calculated' =>
      {
        'type' => 'percent',
        'full' =>
        {
          'source' => 'interface',
          'name'   => 'bps'
        },
        'part' =>
        {
          'source' => 'field',
          'name'   => 'rx_bytes'
        }
      }
    },
    'peack_protect' => 'percent',
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_percent'
    }
  },
  # --------------------------------------------------------------------------
  'tx_percent' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX Utilisation',
      'info'  => 'TX utilisation'
    },
    'source' =>
    {
      'type' => 'calculated',
      'calculated' =>
      {
        'type' => 'percent',
        'full' =>
        {
          'source' => 'interface',
          'name'   => 'bps'
        },
        'part' =>
        {
          'source' => 'field',
          'name'   => 'tx_bytes'
        }
      }
    },
    'peack_protect' => 'percent'
  },
  # --------------------------------------------------------------------------
  'rx_size' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX packet size',
      'info'  => 'Average RX packet size'
    },
    'source' =>
    {
      'type' => 'calculated',
      'calculated' =>
      {
        'type' => 'division',
        'dividend' =>
        {
          'source' => 'field',
          'name'   => 'rx_bytes'
        },
        'divider' =>
        {
          'source' => 'field',
          'name'   => 'rx_packets'
        }
      }
    },
    'peack_protect' => 'packet_size_range',
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_size'
    }
  },
  # --------------------------------------------------------------------------
  'tx_size' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX packet size',
      'info'  => 'Average TX packet size'
    },
    'source' =>
    {
      'type' => 'calculated',
      'calculated' =>
      {
        'type' => 'division',
        'dividend' =>
        {
          'source' => 'field',
          'name'   => 'tx_bytes'
        },
        'divider' =>
        {
          'source' => 'field',
          'name'   => 'tx_packets'
        }
      }
    },
    'peack_protect' => 'packet_size_range'
  },
  # --------------------------------------------------------------------------
  'retries' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Max. retries reached',
      'info'  => 'Max MAC retries num reached'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/retries'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'nwid' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Wrong nwid/essid',
      'info'  => 'Wrong nwid/essid'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/nwid'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'misc' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Other',
      'info'  => 'Others cases'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/misc'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'fragment' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'MAC reassemby',
      'info'  => 'Can\'t perform MAC reassembly'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/fragment'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'beacon' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Missed beacons',
      'info'  => 'Missed beacons/superframe'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/beacon'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'crypt' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'Code/decode',
      'info'  => 'Unable to code/decode (WEP)'
    },
    'source' =>
    {
      'type'     => 'file',
      'location' => $ifpath.'/:if:/wireless/crypt'
    },
    'negative' =>
    {
      'type'  => 'dummy',
      'value' => 'NaN'
    },
    'difference' => 'count'
  },
  # --------------------------------------------------------------------------
  'rx_wifierr' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'RX errors',
      'info'  => 'Total RX Wifi Errors'
    },
    'source' =>
    {
      'type' => 'calculated',
      'calculated' =>
      {
        'type' => 'sum',
        'sum'  => [qw(nwid fragment crypt)]
      }
    },
    'negative' =>
    {
      'type' => 'field',
      'name' => 'tx_wifierr'
    }
  },
  # --------------------------------------------------------------------------
  'tx_wifierr' =>
  {
    'munin' =>
    {
      'type'  => 'GAUGE',
      'draw'  => 'LINE1',
      'label' => 'TX errors',
      'info'  => 'Total TX Wifi errors'
    },
    'source' =>
    {
      'type' => 'calculated',
      'calculated' =>
      {
        'type' => 'sum',
        'sum'  => [qw(misc beacon retries)]
      }
    }
  }
};

# ----------------- main ----------------

need_multigraph();

if (defined($ARGV[0]) and ($ARGV[0] eq 'autoconf'))
{
  printf("%s\n", -e $ifpath ? "yes" : "no ($ifpath not exists)");
  exit (0);
}
$interfaces = get_interfaces();
if (defined($ARGV[0]) and ($ARGV[0] eq 'config'))
{
  print_config();
  exit (0);
}
print_values();
exit(0);


# ====================================== both config and values ===========================
# ---------------  read sysfs file (one file - one value) --------------
sub get_file_content
{
  my $file = $_[0];
  return 'NaN' if (-z $file);
  open (FH, '<', $file) or die "$! $file \n";
  my $content = <FH>;
  close (FH);
  chomp $content;
  #print "$content\n";
  return trim($content);
}

# ------------------ build interface list and his options -------------------------
sub get_interfaces
{
  my $interfaces;
  my $ifdir = IO::Dir->new($ifpath);
  if(defined $ifdir)
  {
    my $if;
    while (defined ($if = $ifdir->read))
    {
      next unless -d "$ifpath/$if";
      next if $if =~ m/\./;
      unless($if =~ m/$include/)
      {
       next unless get_file_content(sprintf("%s/%s/operstate", $ifpath, $if)) =~ m/(up|unknown)/;
       next if $exclude =~ m/$if/;
      }
      my $mtufile = sprintf("%s/%s/mtu", $ifpath, $if);
      if(-e $mtufile)
      {
        $interfaces->{$if}{'mtu'} = get_file_content($mtufile);
      }
      my $bps = $ENV{"${if}_max_bps"} || undef;
      if(defined($bps))
      {
        my ($num, $suff) = $bps =~ /(\d+)(\w)/;
        if   ($suff eq 'k') { $bps = $num * 1000 / 8; }
        elsif($suff eq 'M') { $bps = $num * 1000 * 1000 / 8; }
        elsif($suff eq 'G') { $bps = $num * 1000 * 1000 * 1000 / 8; }
        $interfaces->{$if}{'bps'} = $bps;
      }
      if (-e sprintf("/sys/devices/virtual/net/%s", $if)) { $interfaces->{$if}{'virtual'} = 1; }
      $interfaces->{$if}{'name'} = exists($interfaces->{$if}{'virtual'}) ? sprintf("~%s", $if) : $if;
    }
    my ($maxlen, $tl) = (0, 0);
    for (keys %{$interfaces}) { $tl = length($interfaces->{$_}{'name'}); $maxlen = $tl if $tl > $maxlen;  }
    for (keys %{$interfaces}) { $interfaces->{$_}{'name'} = sprintf("[%${maxlen}s]", $interfaces->{$_}{'name'}); }
  }
  else { die "$ifpath not exists\n"; }

  return $interfaces;
}

# ----------------------- trim whitespace at begin and end of string ------------
sub trim
{
  my($string)=@_;
  for ($string) { s/^\s+//; s/\s+$//; }
  return $string;
}

# ------------------------ replacing :if: from strings to need value ----------------------
sub replace_if_template
{
  my ($string, $replacement) = @_[0..1];
  $string =~ s/:if:/$replacement/g;
  return $string;
}

# --------------------------- calculating range values for peack_protect --------------------------
sub get_peak_range
{
  my ($field, $if) = @_[0..1];
  my $range = {};
  return $range unless defined($fields->{$field}{'peack_protect'});
  # percent
  if ($fields->{$field}{'peack_protect'} eq 'percent')
  {
    $range->{'max'} = 100;
    $range->{'min'} = 0;
  }
  # numbers
  elsif ($fields->{$field}{'peack_protect'} =~ m/[-\d]+:[-\d]+/)
  {
    my @r = split(/:/, $fields->{$field}{'peack_protect'});
    $range->{'max'} = $r[1];
    $range->{'min'} = $r[0];
  }
  # bytes per sec
  elsif($fields->{$field}{'peack_protect'} eq 'max_interface_bps' and defined ($interfaces->{$if}{'bps'}))
  {
    $range->{'max'} = $interfaces->{$if}{'bps'};
    $range->{'min'} = 0;
  }
  # packets per sec
  elsif($fields->{$field}{'peack_protect'} eq 'max_interface_pps' and defined ($interfaces->{$if}{'bps'}))
  {
    $range->{'max'} = $interfaces->{$if}{'bps'}/$min_packet_size;
    $range->{'min'} = 0;
  }
  # packets size range
  elsif($fields->{$field}{'peack_protect'} eq 'packet_size_range' and defined ($interfaces->{$if}{'mtu'}))
  {
    $range->{'max'} = $interfaces->{$if}{'mtu'};
    $range->{'min'} = $min_packet_size;
  }
  return $range;
}


# ----------------------------- checking avialability of fields -------------------------
sub check_field_avialability
{
  my ($if, $field) = @_[0..1];
  unless(exists($fields->{$field}{'avialable'}{$if}))
  {
    # -------------------- file ----------------
    if($fields->{$field}{'source'}{'type'} eq 'file')
    {
      my $file = $fields->{$field}{'source'}{'location'};
      $file =~ s/:if:/$if/g;
      $fields->{$field}{'avialable'}{$if} = 1 if (-e $file);
    }
    #---------------------------- calculated ----------------
    elsif ($fields->{$field}{'source'}{'type'} eq 'calculated')
    {
      #------------------------------ percent ------------------------
      if($fields->{$field}{'source'}{'calculated'}{'type'} eq 'percent')
      {
        my %available;
        for my $a ('full', 'part')
        {
          if($fields->{$field}{'source'}{'calculated'}{$a}{'source'} eq 'interface')
          {
            $available{$a} = exists($interfaces->{$if}{$fields->{$field}{'source'}{'calculated'}{$a}{'name'}});
          }
          elsif($fields->{$field}{'source'}{'calculated'}{$a}{'source'} eq 'field')
          {
            $available{$a} = check_field_avialability($if, $fields->{$field}{'source'}{'calculated'}{$a}{'name'});
          }
        }
        $fields->{$field}{'available'}{$if} = ($available{'full'} and $available{'part'});
      }
      #------------------------------ division ------------------------
      elsif($fields->{$field}{'source'}{'calculated'}{'type'} eq 'division')
      {
        my %available;
        for my $a ('dividend', 'divider')
        {
          if($fields->{$field}{'source'}{'calculated'}{$a}{'source'} eq 'interface')
          {
            $available{$a} = exists($interfaces->{$if}{$fields->{$field}{'source'}{'calculated'}{$a}{'name'}});
          }
          elsif($fields->{$field}{'source'}{'calculated'}{$a}{'source'} eq 'field')
          {
            $available{$a} = check_field_avialability($if, $fields->{$field}{'source'}{'calculated'}{$a}{'name'});
          }
        }
        $fields->{$field}{'available'}{$if} = ($available{'dividend'} and $available{'divider'});
      }
      #------------------------------ sum ------------------------
      elsif($fields->{$field}{'source'}{'calculated'}{'type'} eq 'sum')
      {
        my $count = 0;
        for my $a (@{$fields->{$field}{'source'}{'calculated'}{'sum'}})
        {
          $count++ if (check_field_avialability($if, $a));
        }
        $fields->{$field}{'avialable'}{$if} = ($count == scalar(@{$fields->{$field}{'source'}{'calculated'}{'sum'}}));
      }
    }
  }
  return $fields->{$field}{'avialable'}{$if};
}


# ==================================  config-only ==============================
# --------------- concatenate field names ------------------
sub concat_names
{
  my ($f1, $f2, $if) = @_[0..2];
  my $name = $f1;
  if ($f1 ne $f2)
  {
    my @a = split(' ', $f1);
    my @b = split(' ', $f2);
    my ($t, $ra, $rb) = ('','','');
    for (my $i = scalar(@a) - 1; $i >= 0; $i--)
    {
      #printf("%s %s\n", $a[$i], $b[$i]);
      if   ($a[$i] eq $b[$i]) { $t = sprintf("%s %s", $a[$i], $t); }
      else { $ra = sprintf("%s %s", $a[$i], $ra); $rb = sprintf("%s %s", $b[$i], $rb); }
    }
    $name = trim(sprintf("%s/%s %s", trim($ra), trim($rb), trim($t)));
  }
  if (exists($interfaces->{$if}))
  {
    $name = sprintf ("%s %s", $interfaces->{$if}{'name'}, $name);
  }
  return $name;
}

# --------------------------- generating graph field ----------------------
sub generate_field
{
  my ($config, $graph_name, $field, $if, $is_general_graph) = @_[0..4];
  return '' unless(check_field_avialability($if, $field));
  my $field_graph_name = $is_general_graph ? sprintf("%s_%s", $if, $field) : $field;
  for my $option (keys %{$fields->{$field}{'munin'}})
  {
    next if exists($config->{$graph_name}{'fields'}{$field_graph_name}{$option});
    $config->{$graph_name}{'fields'}{$field_graph_name}{$option} = replace_if_template($fields->{$field}{'munin'}{$option}, $interfaces->{$if}{'name'});
  }
  if(exists($fields->{$field}{'cdef'}))
  {
    $config->{$graph_name}{'fields'}{$field_graph_name}{'cdef'} = sprintf("%s,%s", $field_graph_name, $fields->{$field}{'cdef'});
  }
  if(exists($fields->{$field}{'negative'}))
  {
    my ($up_field_name, $down_field_name) = ('', $field_graph_name);
    my ($up_field, $down_field) = ('', $field);
    if($fields->{$down_field}{'negative'}{'type'} eq 'field')
    {
      $up_field = $fields->{$down_field}{'negative'}{'name'};
      $up_field_name = $is_general_graph ? sprintf("%s_%s", $if, $up_field) : $up_field;
      $config->{$graph_name}{'fields'}{$up_field_name}{'label'} =
        concat_names($fields->{$down_field}{'munin'}{'label'}, $fields->{$up_field}{'munin'}{'label'}, $is_general_graph ? $if : '');
    }
    elsif($fields->{$down_field}{'negative'}{'type'} eq 'dummy')
    {
      $up_field_name = $is_general_graph ? sprintf("%s_%s_dummy", $if, $down_field) : sprintf("%s_dummy", $down_field);
      $config->{$graph_name}{'fields'}{$up_field_name}{'label'} =
        concat_names($fields->{$down_field}{'munin'}{'label'}, $fields->{$down_field}{'munin'}{'label'}, $is_general_graph ? $if : '');
      $config->{$graph_name}{'fields'}{$up_field_name}{'info'} = $fields->{$down_field}{'munin'}{'info'};
    }
    $config->{$graph_name}{'fields'}{$up_field_name}{'negative'} = $down_field_name;
    $config->{$graph_name}{'fields'}{$down_field_name}{'graph'} = 'no';
    $config->{$graph_name}{'fields'}{$down_field_name}{'label'} = 'none';
  }
  # Fix field label on general graphs
  if ($is_general_graph and not $config->{$graph_name}{'fields'}{$field_graph_name}{'label'} =~ m/$if/)
  {
    $config->{$graph_name}{'fields'}{$field_graph_name}{'label'} = sprintf ("%s %s", $interfaces->{$if}{'name'}, $fields->{$field}{'munin'}{'label'});
  }
  # do peaks protect
  if($protect_peacks ne 'no' and exists($fields->{$field}{'peack_protect'}))
  {
    my $range = get_peak_range($field, $if);
    for my $a (qw(min max))
    {
      if (exists($range->{$a}))
      {
        $config->{$graph_name}{'fields'}{$field_graph_name}{$a} = $range->{$a};
      }
    }
  }
  return $field_graph_name;
}

# ------------------------------- generating graph ----------------------------
sub generate_graph
{
  my ($config, $graph, $if, $is_general_graph) = @_[0..4];
  my @order = ();
  my $graph_name = $is_general_graph ? $graph : sprintf("%s.%s", $graph, $if);
  if($is_general_graph)
  {
    for my $field (@{$graphs->{$graph}{'general_fields'}})
    {
      for my $general_if (keys %{$interfaces})
      {
        my $res_field = generate_field($config, $graph_name, $field, $general_if, 1);
        push(@order, $res_field) if $res_field ne '';
      }
    }
  }
  else
  {
    for my $field (@{$graphs->{$graph}{'per_if_fields'}})
    {
      my $res_field = generate_field($config, $graph_name, $field, $if, 0);
      push(@order, $res_field) if $res_field ne '';
    }
  }
  if(scalar(@order) > 0)
  {
    for my $option (keys %{$graphs->{$graph}{'munin'}})
    {
      $config->{$graph_name}{'graph'}{$option} = replace_if_template($graphs->{$graph}{'munin'}{$option}, $is_general_graph ? 'All interfaces' : $interfaces->{$if}{'name'});
    }
    $config->{$graph_name}{'graph'}{'order'} = join(' ', @order); # if scalar(@order) > 1;
    unless($is_general_graph)
    {
      $config->{$graph_name}{'graph'}{'category'} = $if;
    }
  }
}

# ------------------------ generate general and per-interface graphs ------------------------------
sub generate_graphs
{
  my ($config, $graph) = @_[0..1];
  generate_graph($config, $graph, '', 1);
  for my $if (keys %{$interfaces})
  {
    generate_graph($config, $graph, $if, 0);
  }
}

# ---------------------------------------------------------- config ------------------------------------------------------
sub print_config
{
  my $config = {};
  my $graph;
  for $graph (keys %{$graphs}) { generate_graphs($config, $graph); }
  #-------------------- print ---------------
  for $graph (sort  keys %{$config})
  {
    printf ("multigraph %s\n", $graph);
    for my $option (sort keys %{$config->{$graph}{'graph'}})
    {
      printf ("graph_%s %s\n", $option, $config->{$graph}{'graph'}{$option});
    }
    for my $field (sort keys %{$config->{$graph}{'fields'}})
    {
      for my $type (sort keys %{$config->{$graph}{'fields'}{$field}})
      {
        printf ("%s.%s %s\n", $field, $type, $config->{$graph}{'fields'}{$field}{$type});
      }
    }
    print "\n";
  }
}

# ===========================================  values ==========================================================
# ------------------------------- calculate percent --------------------------
sub percent
{
  my ($full, $current) = @_[0..1];
  return $current/($full/100);
}

# ----------------------------------- saving state data using munin --------------------
sub save_state_data
{
  my $data = $_[0];
  my $d = Data::Dumper->new([$data]);
  $d->Indent(0);
  save_state($d->Dump);
}

# -------------------------------- loading previous state data using munin -------------------
sub restore_state_data
{
  my $VAR1;
  my $states = (restore_state())[0];
  eval $states if defined $states;
  return $VAR1;
}

# -------------------- protect field data from under zero value (for example prev tx_bytes = 10000, interface reset, current tx_bytes = 100, 100-1000=-900)
sub underzero_protect
{
  my ($a, $b) = @_[0..1];
  return $a > $b ? $b : $b - $a;
}

# ------------------- calculating difference from last stored data ---------------------------------
sub calc_diff
{
  my ($raw_data, $raw_prev_data, $if, $field) = @_[0..4];
  return $raw_data->{$if}{$field} unless (exists($fields->{$field}{'difference'}) and defined($raw_prev_data));
  if    ($fields->{$field}{'difference'} eq 'count'     ) { return underzero_protect($raw_prev_data->{$if}{$field}, $raw_data->{$if}{$field}); }
  elsif ($fields->{$field}{'difference'} eq 'per_secund') { return underzero_protect($raw_prev_data->{$if}{$field}, $raw_data->{$if}{$field}) / ($raw_data->{'timestamp'} - $raw_prev_data->{'timestamp'}); }
}

# ---------------------- protecting values from peaks ------------------------
sub protect_data_peak
{
  my ($field, $if, $value) = @_[0..2];
  my $range = get_peak_range($field, $if);
  return $value if (
                     $protect_peacks ne 'no'    or
                     (
                      $value ne 'NaN'           and
                      exists($range->{'max'})   and
                      $value <= $range->{'max'} and
                      $value >= $range->{'min'}
                     )
                   );
  return 'NaN';
}

# --------------------------------- loading or calculating fields values ----------------------------
sub get_field_data
{
  my ($data, $raw_data, $raw_prev_data, $if, $field) = @_[0..4];
  unless (exists($data->{$if}{$field}))
  {
    # ----------------------------  file source ------------------------------------------------------------
    if($fields->{$field}{'source'}{'type'} eq 'file' and not exists($raw_data->{$if}{$field}))
    {
      $raw_data->{$if}{$field} = get_file_content(replace_if_template($fields->{$field}{'source'}{'location'}, $if));
      $data->{$if}{$field} = calc_diff($raw_data, $raw_prev_data, $if, $field);
    }
    # ----------------------------  calculated source ------------------------------------------------------------
    elsif($fields->{$field}{'source'}{'type'} eq 'calculated')
    {
      # -------------------------------- percent ---------------------------
      if($fields->{$field}{'source'}{'calculated'}{'type'} eq 'percent')
      {
        my $percents = {};
        for my $pf (qw(full part))
        {
          if ($fields->{$field}{'source'}{'calculated'}{$pf}{'source'} eq 'interface')
          {
            $percents->{$pf} = $interfaces->{$if}{$fields->{$field}{'source'}{'calculated'}{$pf}{'name'}};
          }
          elsif ($fields->{$field}{'source'}{'calculated'}{$pf}{'source'} eq 'field')
          {
            $percents->{$pf} = get_field_data($data, $raw_data, $raw_prev_data, $if, $fields->{$field}{'source'}{'calculated'}{$pf}{'name'});
          }
        }
        $data->{$if}{$field} = percent($percents->{'full'}, $percents->{'part'});
      }
      # -------------------------------- division ---------------------------
      if($fields->{$field}{'source'}{'calculated'}{'type'} eq 'division')
      {
        my $division = {};
        for my $df (qw(dividend divider))
        {
          if ($fields->{$field}{'source'}{'calculated'}{$df}{'source'} eq 'interface')
          {
            $division->{$df} = $interfaces->{$if}{$fields->{$field}{'source'}{'calculated'}{$df}{'name'}};
          }
          elsif ($fields->{$field}{'source'}{'calculated'}{$df}{'source'} eq 'field')
          {
            $division->{$df} = get_field_data($data, $raw_data, $raw_prev_data, $if, $fields->{$field}{'source'}{'calculated'}{$df}{'name'});
          }
        }
        $data->{$if}{$field} = $division->{'divider'} != 0 ? $division->{'dividend'}/$division->{'divider'} : 'NaN';
      }
      # -------------------------------- sum ---------------------------
      if($fields->{$field}{'source'}{'calculated'}{'type'} eq 'sum')
      {
        my $sum = 0;
        for my $s (@{$fields->{$field}{'source'}{'calculated'}{'sum'}})
        {
          $sum += get_field_data($data, $raw_data, $raw_prev_data, $if, $s);
        }
        $data->{$if}{$field} = $sum;
      }
    }
    if(exists($fields->{$field}{'source'}{'prepare'}))
    {
      my $eval = $fields->{$field}{'source'}{'prepare'};
      $eval =~ s/:data:/\$data->{\$if}{\$field}/g;
      eval $eval;
    }
    $data->{$if}{$field} = protect_data_peak($field, $if, $data->{$if}{$field});
  }
  return $data->{$if}{$field};
}

# ------------------------- preparing value for print ----------------------------
sub prepare_value
{
  my ($values, $field, $field_name, $graph_name, $if, $data, $raw_data, $raw_prev_data) = @_[0..7];
  if(check_field_avialability($if, $field))
  {
    $values->{$graph_name}{$field_name} = get_field_data($data, $raw_data, $raw_prev_data, $if, $field);
    if(exists($fields->{$field}{'negative'}) and $fields->{$field}{'negative'}{'type'} eq 'dummy')
    {
      $values->{$graph_name}{$field_name.'_dummy'} = $fields->{$field}{'negative'}{'value'};
    }
  }
}

# --------------------------------- print field.value value for every graph ----------------------
sub print_values
{
  my $data     = {};
  my $raw_data = {};
  my $raw_prev_data = restore_state_data();
  my $values   = {};
  $raw_data->{'timestamp'} = time();
  for my $graph (keys %{$graphs})                                                                                     {
    for my $field (@{$graphs->{$graph}{'general_fields'}})                                                          {
      for my $if (keys %{$interfaces})                                                                            {
        prepare_value($values, $field, sprintf("%s_%s", $if, $field), $graph, $if, $data, $raw_data, $raw_prev_data); } } }
  for my $if (keys %{$interfaces})
  {
    for my $graph (keys %{$graphs})
    {
        my $graph_name = sprintf("%s.%s", $graph, $if);
        for my $field (@{$graphs->{$graph}{'per_if_fields'}})
        {
          prepare_value($values, $field, $field, $graph_name, $if, $data, $raw_data, $raw_prev_data);
        }
    }
  }
  save_state_data($raw_data);
  exit (0) unless defined ($raw_prev_data); # first update need just for collect and save data
  # ------------------------ print ------------------------
  for my $graph (sort (keys %{$values}))
  {
    printf ("multigraph %s\n", $graph);
    for my $field (sort keys %{$values->{$graph}})
    {
      printf("%s.value %s\n", $field, $values->{$graph}{$field});
    }
    print "\n";
  }
}