router-scripts/observium/snmpd_ifAliasBird

#! /usr/bin/perl

use strict;

my $baseoid = ".1.3.6.1.2.1.31.1.1.1.18";

my $cache_secs = 60;

# ----------------------------------

my $mib;
my $mibtime;

$| = 1;

while (my $cmd = <STDIN>) {
  chomp $cmd;
  if ($cmd eq "PING") {
    print "PONG\n";
  } elsif ($cmd eq "get") {
    my $oid_in = <STDIN>;
    chomp($oid_in);
    my $oid = get_oid($oid_in);
    my $mib = create_alias_mib();

    if ($oid != 0 && defined{$mib->{$oid}}) {
      print "$baseoid.$oid\n";
      print $mib->{$oid}[0]."\n";
      print $mib->{$oid}[1]."\n";
    } else {
      print "NONE\n";
    }

  } elsif ($cmd eq "getnext") {
    my $oid_in = <STDIN>;

    my $oid = get_oid($oid_in);
    my $found = 0;

    my $mib = create_alias_mib();
    my @s = sort { oidcmp($a, $b) } keys %{ $mib };
    for (my $i = 0; $i < @s; $i++) {
      if (oidcmp($oid, $s[$i]) == -1) {
        print "$baseoid.".$s[$i]."\n";
        print $mib->{$s[$i]}[0]."\n";
        print $mib->{$s[$i]}[1]."\n";
        $found = 1;
        last;
      }
    }
    if (!$found) {
      print "NONE\n";
    }
  } else {
    # Unknown command
  }
}

exit 0;


sub get_oid
{

  my ($oid) = @_;
  chomp $oid;

  my $base = $baseoid;
  $base =~ s/\./\\./g;

  if ($oid !~ /^$base(\.|$)/) {
    # Requested oid doesn't match base oid
    return 0;
  }

  $oid =~ s/^$base\.?//;
  return $oid;
}

sub oidcmp {
  my ($x, $y) = @_;

  my @a = split /\./, $x;
  my @b = split /\./, $y;

  my $i = 0;

  while (1) {

    if ($i > $#a) {
      if ($i > $#b) {
        return 0;
      } else {
        return -1;
      }
    } elsif ($i > $#b) {
      return 1;
    }

    if ($a[$i] < $b[$i]) {
      return -1;
    } elsif ($a[$i] > $b[$i]) {
      return 1;
    }

    $i++;
  }
}

sub create_alias_mib
{
  # We cache the results for $cache_secs seconds
  if (time - $mibtime < $cache_secs) {
    return $mib;
  }

  my %name;
  my %alias;

  # retrieve the interface alias & number
  open Q, "/usr/local/sbin/birdc sh interfaces |";
  while(my $l = <Q>) {
    chomp($l);
    if ($l =~ /^([^[:space:]]+)[[:space:]]([^[:space:]]+)[[:space:]]\(index=(\d+)\).*/) {
      $name{$1} = [ $3 ];
    }
  }
  close Q;

  open Q, "( if [ -e /etc/network/interfaces ]; then cat /etc/network/interfaces; elif [ -e /etc/rc.conf ]; then cat /etc/rc.conf; fi) |";
  while(my $l = <Q>) {
    chomp($l);
    if ($l =~ /^# ([^:]*): (.*)$/) {
      $alias{$name{$1}[0]} = [ "string", $2 ];
    }
  }
  close Q;
  $mib = \%alias;
  $mibtime = time;
  return $mib;
}