#!/usr/bin/perl
use IO::Socket::UNIX;
use Munin::Plugin;
use strict;
use warnings;
use v5.10;

=head1 NAME

bird - Munin multigraph plugin to monitor BIRD routing daemon activity

=head1 APPLICABLE SYSTEMS

Every system with running bird

=head1 CONFIGURATION

The plugin must run with a user or group that could connect to bird
control socket.

This configuration snipplet is an example with the defaults:

  [bird]
    user root
    protocols BGP
    socket /var/run/bird.ctl

=head1 USAGE

Link this plugin to /etc/munin/plugins/ and restart the munin-node.

=head1 MAGIC MARKERS

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

=head1 BUGS

Not known

=head1 AUTHOR

Luben Karavelov (karavelov at mail.bg)

=head1 LICENSE

Same as perl

=cut

need_multigraph();
my $protocols = [ split(/ /, $ENV{'protocols'} || 'BGP') ];
my $socket    = $ENV{'socket'} || '/var/run/bird.ctl';

sub get_stats {
    state $stats;
    return $stats if defined $stats;

    my $bird_ctl = IO::Socket::UNIX->new(
            Type => SOCK_STREAM,
            Peer => $socket
        ) or die $!;

    my ($protocol,$name);
    while (my $var = <$bird_ctl>) {
        given($var) {
            when (/1002-(\w+)\s+(\w+)\s+.*/) {
                ($name, $protocol) = ($1,$2);
                next unless $protocol ~~ $protocols;
                $stats->{$name}->{protocol} = $protocol;
            }
            when (/^0001 /) {
                print $bird_ctl "show protocols all\n";
                next;
            }
            when (/^0000 /) {
                last;
            }
            when (/^1002- /) {
                print;
            }
            when (/^1006-\s+Description:\s+(.+)$/){
                next unless $protocol ~~ $protocols;
                $stats->{$name}->{title} = $1;
            }
            when (/^\s+Routes:\s+(\d+)\s+imported,\s+(\d+)\s+exported,\s+(\d+)\s+preferred$/){
                next unless $protocol ~~ $protocols;
                $stats->{$name}->{imported} = $1;
                $stats->{$name}->{exported} = $2;
                $stats->{$name}->{preferred} = $3;
            }
            # received   rejected   filtered    ignored   accepted
            when (/^\s+(Import|Export)\s(updates|withdraws):\s+(\d+|-+)\s+(\d+|-+)\s+(\d+|-+)\s+(\d+|-+)\s+(\d+|-+)$/){
                next unless $protocol ~~ $protocols;
                $stats->{$name}->{ lc("$1_$2_received") } = $3;
                $stats->{$name}->{ lc("$1_$2_rejected") } = $4;
                $stats->{$name}->{ lc("$1_$2_filtered") } = $5;
                $stats->{$name}->{ lc("$1_$2_ignored" ) } = $6;
                $stats->{$name}->{ lc("$1_$2_accepted") } = $7;
            }
            when (/^$/) {
                undef $protocol;
                undef $name;
            }
        }
    }
    $bird_ctl->close;
    return $stats;
}

sub autoconf {
    if (-S $socket) {
        say 'yes';
    } else {
        say 'no';
    }
    exit 0;
}

sub config {
    my $stats = get_stats;
    while ( my ($name,$proto) = each %$stats) {
        print <<HEREDOC;
multigraph ${name}_routes
graph_title $proto->{title} routes
graph_args --base 1000
graph_vlabel routes
graph_category network
exported.label Exported routes
exported.type GAUGE
exported.info Exported routes
exported.min 0
exported.draw LINE1
imported.label Imported routes
imported.type GAUGE
imported.info Impored routes
imported.min 0
imported.draw LINE1
preferred.label Preferred routes
preferred.type GAUGE
preferred.info Preferred routes
preferred.min 0
preferred.draw LINE1
multigraph ${name}_activity
graph_title $proto->{title} activity
graph_args --base 1000
graph_vlabel routes per second
graph_category network
import_updates_received.label Import updates received
import_updates_received.type DERIVE
import_updates_received.draw LINE1
import_updates_rejected.label Import updates rejected
import_updates_rejected.type DERIVE
import_updates_rejected.draw LINE1
import_updates_filtered.label Import updates filtered
import_updates_filtered.type DERIVE
import_updates_filtered.draw LINE1
import_updates_ignored.label Import updates ignored
import_updates_ignored.type DERIVE
import_updates_ignored.draw LINE1
import_updates_accepted.label Import updates accepted
import_updates_accepted.type DERIVE
import_updates_accepted.draw LINE1
import_withdraws_received.label Import withdraws_received
import_withdraws_received.type DERIVE
import_withdraws_received.draw LINE1
import_withdraws_rejected.label Import withdraws rejected
import_withdraws_rejected.type DERIVE
import_withdraws_rejected.draw LINE1
import_withdraws_ignored.label Import withdraws ignored
import_withdraws_ignored.type DERIVE
import_withdraws_ignored.draw LINE1
import_withdraws_accepted.label Import withdraws accepted
import_withdraws_accepted.type DERIVE
import_withdraws_accepted.draw LINE1
export_updates_received.label Export updates received
export_updates_received.type DERIVE
export_updates_received.draw LINE1
export_updates_rejected.label Export updates rejected
export_updates_rejected.type DERIVE
export_updates_rejected.draw LINE1
export_updates_filtered.label Export updates filtered
export_updates_filtered.type DERIVE
export_updates_filtered.draw LINE1
export_updates_accepted.label Export updates accepted
export_updates_accepted.type DERIVE
export_updates_accepted.draw LINE1
export_withdraws_received.draw LINE1
export_withdraws_received.label Export withdraws received
export_withdraws_received.type DERIVE
export_withdraws_accepted.label Export withdraws accepted
export_withdraws_accepted.type DERIVE
export_withdraws_accepted.draw LINE1
HEREDOC
    }
}

sub fetch {
    my $stats = get_stats;
    while ( my ($name,$proto) = each %$stats) {
        print <<HEREDOC;
multigraph ${name}_routes
exported.value $proto->{exported}
imported.value $proto->{imported}
preferred.value $proto->{preferred}
multigraph ${name}_activity
import_updates_received.value $proto->{import_updates_received}
import_updates_rejected.value $proto->{import_updates_rejected}
import_updates_filtered.value $proto->{import_updates_filtered}
import_updates_ignored.value $proto->{import_updates_ignored}
import_updates_accepted.value $proto->{import_updates_accepted}
import_withdraws_received.value $proto->{import_withdraws_received}
import_withdraws_rejected.value $proto->{import_withdraws_rejected}
import_withdraws_ignored.value $proto->{import_withdraws_ignored}
import_withdraws_accepted.value $proto->{import_withdraws_accepted}
export_updates_received.value $proto->{export_updates_received}
export_updates_rejected.value $proto->{export_updates_rejected}
export_updates_filtered.value $proto->{export_updates_filtered}
export_updates_accepted.value $proto->{export_updates_accepted}
export_withdraws_received.value $proto->{export_withdraws_received}
export_withdraws_accepted.value $proto->{export_withdraws_accepted}
HEREDOC
    }
}

given ($ARGV[0]) {
    when ('autoconf') { autoconf }
    when ('config')   { config   }
    default           { fetch    }
}