#! /usr/bin/perl

use strict;

my $baseoid = ".1.3.6.1.2.1.31.1.1.1.18";

my $vtysh = "sudo -n /usr/bin/vtysh -c 'sh interface description'";

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>;
        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, "ip link |";
   while(my $l = <Q>) {
	chomp($l);
        if ($l =~ /^(\d+): ([^:@]+)(@[^:]+)?: .*/) {
               $name{$2} = [ $1 ];
        }
   }
   close Q;

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