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

=head1 NAME

irq - Plugin to monitor interrupts.

=head1 APPLICABLE SYSTEMS

All Linux systems

=head1 CONFIGURATION

None need

=head2 WARNING AND CRITICAL SETTINGS

You can set warning and critical levels for each of the data
series the plugin reports.
'General' graph support cpu-irqtype limits and irqtype limits

Examples:

 [irq]
 env.warning_cpu1_sirq_total 550
 env.critical_cpu0_irq_total 600
 env.warning_irq_total 700
 env.critical_sirq_total 700

'Child' graphs support cpu-irqtype-irqname and irqtype-irqname limits

Examples:

 [irq]
 env.warning_cpu0_irq_7 100
 env.critical_cpu1_sirq_HI 100
 env.warning_irq_LOC 100
 env.critical_irq_12 200
 env.warning_sirq_BLOCK 1000

Note: irqtype: sirq, irq; sirq - Software IRQ; irq name you can see in [] on graph

=head1 INTERPRETATION

The plugin shows each cpu interrupts: summary and IRQ/Software IRQ per CPU

=head1 MAGIC MARKERS

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

=head1 VERSION

  1.0

=head1 BUGS

I can not understand, how set limit to mirrored fields, so they may not display correctly

=head1 AUTHOR

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

=head1 LICENSE

GPLv2

=cut

use strict;
use warnings;
use Munin::Plugin;
use Data::Dumper;
my $IRQi = {};


my $graphs =
{
  'irq_total' =>
  {
    'title'    => 'Interrupts per cpu',
    'args'     => '--base 1000',
    'vlabel'   => 'count of IRQ (+) / sIRQ (-) per second',
    'info'     => 'This graph shows interrupts per second from last update',
    'category' => 'system'
  },
  'irq_cpu' =>
  {
    'title'    => 'CPU:cpu: :irq_type:',
    'args'     => '--base 1000',
    'vlabel'   => 'count per second',
    'info'     => 'This graph shows :irq_type: for CPU:cpu: per second from last update',
    'category' => 'cpu :cpu:'
  }
};

my $fields =
{
  'irq' =>
  {
    'label' => '[:irq:] :irqinfo:',
    'info'  => ':irq:: :irqinfo:',
    'type'  => 'GAUGE',
    'draw'  => 'LINE1'
  },
  'irq_sirq' =>
  {
    'label' => 'CPU:cpu: sIRQ/IRQ',
    'info'  => 'Total sIRQ/IRQ for CPU:cpu:',
    'type'  => 'GAUGE',
    'draw'  => 'LINE1'
  }
};

my $irq_types =
{
  'irq'  => 'Interrupts',
  'sirq' => 'Software interrupts'
};

my $irq_descriptions =
{
  'HI'      => 'High priority tasklets',
  'TIMER'   => 'Timer bottom half',
  'NET_TX'  => 'Transmit network packets',
  'NET_RX'  => 'Receive network packets',
  'SCSI'    => 'SCSI bottom half',
  'TASKLET' => 'Handles regular tasklets'
};

# ----------------- main ----------------
need_multigraph();
# -- autoconf --
if (defined($ARGV[0]) and ($ARGV[0] eq 'autoconf'))
{
  printf("%s\n", (-e "/proc/interrupts" and -e "/proc/softirqs") ? "yes" : "no (stats not exists)");
  exit (0);
}
# -- config --
load_irq_info();
if (defined($ARGV[0]) and ($ARGV[0] eq 'config')) { print_config(); exit (0); }
# -- values --
print_values(); exit(0);

# ----------------- sub's ----------------

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


# -------------------------- loading irq stats ---------------------------------
sub load_irq_info_file
{
  my $file      = $_[0];
  my $info      = {};
  my $cpu_count = 0;
  my $summ      = 0;
  open (FH, '<', $file) or die "$! $file \n";
  for my $line (<FH>)
  {
    chomp $line;
    if($line =~ m/:/)
    {
      my ($name, $stat) = split(/:/, trim($line));
      my @data = split(/\s+/, trim($stat));
      for (my $i=0; $i<$cpu_count; $i++)
      {
        if (defined $data[$i])
        {
          $info->{'info'}{$i}{$name} = $data[$i];
          $info->{'summ'}{$i}       += $data[$i];
        }
      }
      if(scalar(@data) > $cpu_count)
      {
        my $iname = '';
        ($iname = $line) =~ s/^.*:(\s+\d+)+\s+(.*)$/$2/;
        if ($iname ne '')
        {
          if ($iname =~ m/.*-.*-.*/)
          {
            my @parts = ($iname =~ /^((\w+-)*\w+)\s+(.*)\s*$/g);
            $iname = sprintf("%s (%s)", $parts[0], $parts[2]);
          }
          $info->{'description'}{$name} = $iname;
        }
      }
      elsif(exists ($irq_descriptions->{$name}))
      {
        $info->{'description'}{$name} = $irq_descriptions->{$name};
      }
    }
    else
    {
      my @cpus = split(/\s+/, trim($line));
      $cpu_count = scalar(@cpus);
      for (my $i=0; $i<$cpu_count; $i++)
      {
        $info->{'summ'}{$i} = 0;
      }
    }
  }
  close (FH);
  $info->{'cpu_count'} = $cpu_count;
  return $info;
}

# -------------- loading all IRQ statistics ---------------------------
sub load_irq_info
{
  my ($irq, $sirq) = (load_irq_info_file("/proc/interrupts"), load_irq_info_file("/proc/softirqs"));
  $IRQi->{'stat'}{'irq' } = $irq ->{'info'};
  $IRQi->{'stat'}{'sirq'} = $sirq->{'info'};
  $IRQi->{'summ'}{'irq' } = $irq ->{'summ'};
  $IRQi->{'summ'}{'sirq'} = $sirq->{'summ'};
  $IRQi->{'description'}{'irq' } = $irq ->{'description'} if exists($irq ->{'description'});
  $IRQi->{'description'}{'sirq'} = $sirq->{'description'} if exists($sirq->{'description'});
  $IRQi->{'cpu_count'} = $irq ->{'cpu_count'};
}

# ------------------ loading limits ---------------------
sub load_limits
{
  my $flags = {};
  my $limits = {};
  my $name = '';
  for my $irq_type (qw(irq sirq))
  {
    for my $t (qw(warning critical))
    {
      $name = sprintf("%s_%s_total", $t, $irq_type); # env.warning_irq_total 22
      $limits->{'irq_total'}{$irq_type}{$t} = $ENV{$name} || undef;
      for (my $i=0; $i < $IRQi->{'cpu_count'}; $i++)
      {
        $name = sprintf("%s_cpu%s_%s_total", $t, $i, $irq_type); # env.warning_cpu1_sirq_total 1112
        $limits->{'irq_total_percpu'}{$irq_type}{$t}{$i} = $ENV{$name} || undef;
        for my $irq_name (keys %{$IRQi->{'stat'}{$irq_type}{$i}})
        {
          $name = sprintf("%s_cpu%s_%s_%s", $t, $i, $irq_type, $irq_name); # env.warning_cpu0_irq_7 25
          $limits->{'percpu_perirq'}{$irq_type}{$t}{$i}{$irq_name} = $ENV{$name} || undef;
          $name = sprintf("%s_%s_%s", $t, $irq_type, $irq_name);
          unless (exists($flags->{$name}))
          {
            $limits->{'perirq'}{$irq_type}{$t}{$irq_name} = $ENV{$name} || undef; # env.critical_sirq_RCU 14
            $flags->{$name} = 1;
          }
        }
      }
    }
  }
  return $limits;
}

# -------------------------------- replacing strings ------------------------
sub replace
{
  my ($string, $needle, $replacement) = @_[0..2];
  $string =~ s/$needle/$replacement/g;
  return $string;
}

# ----------------- append limit values to general graph fields-----------------------------
sub append_total_limit
{
  my ($limits, $gr, $irq_type, $field_name, $cpu_num) = @_[0..4];
  for my $t (qw(warning critical))
  {
    my $limit = defined($limits->{'irq_total_percpu'}{$irq_type}{$t}{$cpu_num}) ? $limits->{'irq_total_percpu'}{$irq_type}{$t}{$cpu_num} :
                ($limits->{'irq_total'}{$irq_type}{$t} || undef);
    if (defined($limit))
    {
      $gr->{'irq'}{'fields'}{$field_name}{$t} = $limit;
    }
  }
}

# ----------------- append limit values to chields graphs fields-----------------------------
sub append_cpu_limit
{
  my ($limits, $gr, $irq_type, $field_name, $graph_name, $cpu_num, $irq_name) = @_[0..6];
  for my $t (qw(warning critical))
  {
    my $limit = defined($limits->{'percpu_perirq'}{$irq_type}{$t}{$cpu_num}{$irq_name}) ? $limits->{'percpu_perirq'}{$irq_type}{$t}{$cpu_num}{$irq_name} :
                ($limits->{'perirq'}{$irq_type}{$t}{$irq_name} || undef);
    if (defined($limit))
    {
      $gr->{$graph_name}{'fields'}{$field_name}{$t} = $limit;
    }
  }
}

# ------------------------------ preparing graphs configurations ------------------------------
sub prepare_graphs
{
  my $gr = {};
  my $limits = load_limits();
  # --- general graph ---
  $gr->{'irq'}{'graph'} = $graphs->{'irq_total'};
  $gr->{'irq'}{'graph'}{'order'} = "";
  for (my $i=0; $i < $IRQi->{'cpu_count'}; $i++)
  {
    # --- general fields ---
    my ($up_field_name, $down_field_name) = (sprintf("i%s", $i), sprintf("si%s", $i));
    append_total_limit($limits, $gr, 'irq',  $up_field_name,   $i);
    append_total_limit($limits, $gr, 'sirq', $down_field_name, $i);
    $gr->{'irq'}{'graph'}{'order'} .= sprintf(" %s %s", $down_field_name, $up_field_name);
    $gr->{'irq'}{'fields'}{$up_field_name}{'type'}   = $fields->{'irq_sirq'}{'type'};
    $gr->{'irq'}{'fields'}{$down_field_name}{'type'} = $fields->{'irq_sirq'}{'type'};
    $gr->{'irq'}{'fields'}{$up_field_name}{'draw'}   = $fields->{'irq_sirq'}{'draw'};
    $gr->{'irq'}{'fields'}{$down_field_name}{'draw'} = $fields->{'irq_sirq'}{'draw'};

    $gr->{'irq'}{'fields'}{$up_field_name}{'label'} = replace($fields->{'irq_sirq'}{'label'}, ':cpu:', $i);
    $gr->{'irq'}{'fields'}{$up_field_name}{'info'}  = replace($fields->{'irq_sirq'}{'info'} , ':cpu:', $i);
    $gr->{'irq'}{'fields'}{$down_field_name}{'label'} = 'NaN';
    $gr->{'irq'}{'fields'}{$down_field_name}{'info'}  = 'NaN';

    $gr->{'irq'}{'fields'}{$up_field_name}{'negative'} = $down_field_name;
    $gr->{'irq'}{'fields'}{$down_field_name}{'graph'}  = 'no';

    # --- child graphs ---
    for my $irq_type (qw(irq sirq))
    {
      my $graph_name = sprintf("irq.%s_cpu%s", $irq_type, $i);
      $gr->{$graph_name}{'graph'}{'order'} = "";
      $gr->{$graph_name}{'graph'}{'args'} = $graphs->{'irq_cpu'}{'args'};
      $gr->{$graph_name}{'graph'}{'vlabel'} = $graphs->{'irq_cpu'}{'vlabel'};
      for my $go (qw(title info))
      {
        $gr->{$graph_name}{'graph'}{$go} = replace($graphs->{'irq_cpu'}{$go}, ':irq_type:', $irq_types->{$irq_type});
        $gr->{$graph_name}{'graph'}{$go} = replace($gr->{$graph_name}{'graph'}{$go}, ':cpu:', $i);
      }
      $gr->{$graph_name}{'graph'}{'category'} = replace($graphs->{'irq_cpu'}{'category'}, ':cpu:', $i);
      # -- child fields --
      my @irq_names = keys %{$IRQi->{'stat'}{$irq_type}{$i}};
      # names split for better sorting
      for my $irq_name ((
                          (sort {int $a <=> int $b} grep{/^\d/}            @irq_names),
                          (sort                     grep{!/(^\d|ERR|MIS)/} @irq_names),
                          (sort                     grep{/(ERR|MIS)/     } @irq_names)
                        ))
      {
        my $field_name = clean_fieldname(sprintf("irq_%s", $irq_name));
        append_cpu_limit($limits, $gr, $irq_type, $field_name, $graph_name, $i, $irq_name);
        $gr->{$graph_name}{'graph'}{'order'} .= ' '.$field_name;
        for my $this_field (qw(label info))
        {
          $gr->{$graph_name}{'fields'}{$field_name}{$this_field} = replace($fields->{'irq'}{$this_field}, ':irq:', $irq_name);
          $gr->{$graph_name}{'fields'}{$field_name}{$this_field} = replace($gr->{$graph_name}{'fields'}{$field_name}{$this_field},
                                                                   ':irqinfo:',
                                                                   exists($IRQi->{'description'}{$irq_type}{$irq_name}) ?
                                                                    $IRQi->{'description'}{$irq_type}{$irq_name} :
                                                                    '');
        }
        $gr->{$graph_name}{'fields'}{$field_name}{'type'} = $fields->{'irq'}{'type'};
        $gr->{$graph_name}{'fields'}{$field_name}{'draw'} = $fields->{'irq'}{'draw'};
      }
    }
  }
  return $gr;
}

# --------------------------------- graph configs ----------------------------
sub print_config
{
  my $config = prepare_graphs();
  for my $g (sort keys %{$config})
  {
    printf("multigraph %s\n", $g);
    for my $go (sort keys %{$config->{$g}{'graph'}}) { printf("graph_%s %s\n", $go, $config->{$g}{'graph'}{$go}); }
    for my $f (sort keys %{$config->{$g}{'fields'}}) { for my $this_field (sort keys %{$config->{$g}{'fields'}{$f}}) { printf("%s.%s %s\n", $f, $this_field, $config->{$g}{'fields'}{$f}{$this_field}); } }
    print "\n";
  }
}

# ----------------------------------- 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;
}

# ----------------------------- loading statistic and save it for feature use--------------
sub load_stats
{
  delete ($IRQi->{'description'});
  $IRQi->{'timestamp'} = time();
  save_state_data($IRQi);
  return $IRQi;
}

# ----------- calculate current and previous values difference -----------------------
sub diff_value
{
  my ($pvalue, $cvalue, $timediff) = @_[0..2];
  return 'NaN' if $timediff <= 0 or $pvalue > $cvalue;
  return ($cvalue - $pvalue)/$timediff;
}

# -----------------  calculating values ---------------------
sub calculate
{
  my ($pstats, $cstats) = @_[0..1];
  my $data = {};
  my $timediff = $cstats->{'timestamp'} - $pstats->{'timestamp'};
  for my $irq_type (qw(irq sirq))
  {
    for (my $i=0; $i < $IRQi->{'cpu_count'}; $i++)
    {
      $data->{'summ'}{$irq_type}{$i} = diff_value($pstats->{'summ'}{$irq_type}{$i}, $cstats->{'summ'}{$irq_type}{$i}, $timediff);
      for my $irq_name (keys %{$cstats->{'stat'}{$irq_type}{$i}})
      {
        $data->{'stat'}{$irq_type}{$i}{$irq_name} = diff_value($pstats->{'stat'}{$irq_type}{$i}{$irq_name}, $cstats->{'stat'}{$irq_type}{$i}{$irq_name}, $timediff);
      }
    }
  }
  return $data;
}

# --------------------- preparing graphs values config ------------------------
sub prepare_graphs_values
{
  my $data = $_[0];
  my $values = {};
  for (my $i=0; $i < $IRQi->{'cpu_count'}; $i++)
  {
    $values->{'irq'}{sprintf("i%s",  $i)} = $data->{'summ'}{'irq'} {$i};
    $values->{'irq'}{sprintf("si%s", $i)} = $data->{'summ'}{'sirq'}{$i};
    for my $irq_type (qw(irq sirq))
    {
      my $graph_name = sprintf("irq.%s_cpu%s", $irq_type, $i);
      for my $irq_name (keys %{$data->{'stat'}{$irq_type}{$i}})
      {
        my $field_name = clean_fieldname(sprintf("irq_%s", $irq_name));
        $values->{$graph_name}{$field_name} = $data->{'stat'}{$irq_type}{$i}{$irq_name};
      }
    }
  }
  return $values;
}

# -------------------------------- printing values -----------------------------------
sub print_values
{
  my $pstats = restore_state_data();
  my $cstats = load_stats();
  if (exists ($pstats->{'timestamp'}))
  {
    my $values = prepare_graphs_values(calculate($pstats, $cstats));
    for my $g (sort keys %{$values})
    {
      printf("multigraph %s\n", $g);
      for my $f (sort keys %{$values->{$g}}) { printf("%s.value %s\n", $f, $values->{$g}{$f}); }
      print "\n";
    }
  }
}