#!/usr/bin/env perl

use warnings;
use strict;

use File::Basename;
use File::Fetch;
use Getopt::Long;
use IPC::Cmd qw/can_run/;
use Pod::Usage;

use LWP::Simple;
use PerlIO::gzip;
use URI;

$LWP::Simple::ua->show_progress(1);

my %config = (
    asn_sources => [
        'ftp://ftp.arin.net/pub/stats/arin/delegated-arin-extended-latest',
        'ftp://ftp.ripe.net/ripe/stats/delegated-ripencc-latest',
        'ftp://ftp.afrinic.net/pub/stats/afrinic/delegated-afrinic-latest',
        'ftp://ftp.apnic.net/pub/stats/apnic/delegated-apnic-latest',
        'ftp://ftp.lacnic.net/pub/stats/lacnic/delegated-lacnic-latest'
    ],
    bgp_sources => ['http://data.ris.ripe.net/rrc00/latest-bview.gz']
);

my $download_asn    = 0;
my $download_bgp    = 0;
my $download_target = "./";
my $help            = 0;
my $man             = 0;
my $v4              = 1;
my $v6              = 1;
my $parse           = 1;
my $v4_zone         = "asn.rspamd.com";
my $v6_zone         = "asn6.rspamd.com";
my $v4_file         = "asn.zone";
my $v6_file         = "asn6.zone";
my $ns_servers      = [ "asn-ns.rspamd.com", "asn-ns2.rspamd.com" ];
my $use_bgpdump     = 0;

GetOptions(
    "download-asn" => \$download_asn,
    "download-bgp" => \$download_bgp,
    "4!"           => \$v4,
    "6!"           => \$v6,
    "parse!"       => \$parse,
    "target=s"     => \$download_target,
    "zone-v4=s"    => \$v4_zone,
    "zone-v6=s"    => \$v6_zone,
    "file-v4=s"    => \$v4_file,
    "file-v6=s"    => \$v6_file,
    "ns-server=s@" => \$ns_servers,
    "help|?"       => \$help,
    "man"          => \$man,
) or pod2usage(2);

pod2usage(1) if $help;
pod2usage( -exitval => 0, -verbose => 2 ) if $man;

my $bgpdump_path = can_run('bgpdump')
  or warn 'bgpdump is not found, will try to use Net::MRT instead; results can be incomplete';

sub download_file {
    my ($u) = @_;

    print "Fetching $u\n";
    my $ff    = File::Fetch->new( uri => $u );
    my $where = $ff->fetch( to => $download_target ) or die $ff->error;

    return $where;
}

if ($download_asn) {
    foreach my $u ( @{ $config{'asn_sources'} } ) {
        download_file($u);
    }
}

if ($download_bgp) {
    foreach my $u ( @{ $config{'bgp_sources'} } ) {
        download_file($u);
    }
}

if ( !$parse ) {
    exit 0;
}

my $v4_fh;
my $v6_fh;

if ($v4) {
    open( $v4_fh, ">", $v4_file ) or die "Cannot open $v4_file for writing: $!";
    print $v4_fh "\$SOA 43200 $ns_servers->[0] support.rspamd.com 0 600 300 86400 300\n";
    foreach my $ns ( @{$ns_servers} ) {
        print $v4_fh "\$NS 43200 $ns\n";
    }
}
if ($v6) {
    open( $v6_fh, ">", $v6_file ) or die "Cannot open $v6_file for writing: $!";
    print $v6_fh "\$SOA 43200 $ns_servers->[0] support.rspamd.com 0 600 300 86400 300\n";
    foreach my $ns ( @{$ns_servers} ) {
        print $v6_fh "\$NS 43200 $ns\n";
    }
}

sub is_bougus_asn {
    my $as = shift;

    # 64496-64511 Reserved for use in documentation and sample code
    # 64512-65534 Designated for private use
    # 65535       Reserved
    # 65536-65551 Reserved for use in documentation and sample code
    # 65552-131071 Reserved
    return 1 if $as >= 64496 && $as <= 131071;

    # 4294967295
    return 1 if $as == 4294967295;

    # AS0 is reserved
    # AS1 is legal AS, but in most cases used by others without permission
    # of owner (probably lame admins use AS1 as private AS).
    return 1 if $as <= 1;

    return 0;
}

# Now load BGP data
my $networks = {};

foreach my $u ( @{ $config{'bgp_sources'} } ) {
    my $parsed = URI->new($u);
    my $fname  = $download_target . '/' . basename( $parsed->path );

    if ($bgpdump_path) {
        use constant {
            F_MARKER    => 0,
            F_TIMESTAMP => 1,
            F_PEER_IP   => 3,
            F_PEER_AS   => 4,
            F_PREFIX    => 5,
            F_AS_PATH   => 6,
            F_ORIGIN    => 7,
        };

        open( my $bgpd, '-|', "$bgpdump_path -v -M $fname" ) or die "can't start bgpdump: $!";

        while (<$bgpd>) {
            chomp;
            my @e = split /\|/;
            if ( $e[F_MARKER] ne 'TABLE_DUMP2' ) {
                warn "bad line: $_\n";
                next;
            }

            my $origin_as;
            my $prefix = $e[F_PREFIX];
            my $ipv6   = 0;

            if ( $prefix !~ /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\/\d{1,2}$/ ) {
                $ipv6 = 1;
            }

            if ( $e[F_AS_PATH] ) {

                # not empty AS_PATH
                my @as_path = split /\s/, $e[F_AS_PATH];
                $origin_as = pop @as_path;

                if ( substr( $origin_as, 0, 1 ) eq '{' ) {

                    # route is aggregated
                    if ( $origin_as =~ /^{(\d+)}$/ ) {

                        # single AS aggregated, just remove { } around
                        $origin_as = $1;
                    }
                    else {
                        # use previous AS from AS_PATH
                        $origin_as = pop @as_path;
                    }
                }

                # strip bogus AS
                while ( is_bougus_asn($origin_as) ) {
                    $origin_as = pop @as_path;
                    last if scalar @as_path == 0;
                }
            }

            # empty AS_PATH or all AS_PATH elements is stripped as bogus - use PEER_AS is origin AS
            $origin_as //= $e[F_PEER_AS];

            if ( !$networks->{$origin_as} ) {
                if ( !$ipv6 ) {
                    $networks->{$origin_as} = { nets_v4 => [$prefix], nets_v6 => [] };
                }
                else {
                    $networks->{$origin_as} = { nets_v6 => [$prefix], nets_v4 => [] };
                }
            }
            else {
                if ( !$ipv6 ) {
                    push @{ $networks->{$origin_as}->{'nets_v4'} }, $prefix;
                }
                else {
                    push @{ $networks->{$origin_as}->{'nets_v6'} }, $prefix;
                }
            }
        }
    }
    else {
        require Net::MRT;
        $Net::MRT::USE_RFC4760 = -1;

        open( my $fh, "<:gzip", $fname )
          or die "Cannot open $fname: $!";
        while ( my $dd = eval { Net::MRT::mrt_read_next($fh) } ) {
            if ( $dd->{'prefix'} && $dd->{'bits'} ) {
                next if $dd->{'subtype'} == 2 and !$v4;
                next if $dd->{'subtype'} == 4 and !$v6;
                my $entry = $dd->{'entries'}->[0];
                my $net   = $dd->{'prefix'} . '/' . $dd->{'bits'};
                if ( $entry && $entry->{'AS_PATH'} ) {
                    my $as = $entry->{'AS_PATH'}->[-1];
                    if ( ref($as) eq "ARRAY" ) {
                        $as = @{$as}[0];
                    }

                    next if ( is_bougus_asn($as) );

                    if ( !$networks->{$as} ) {
                        if ( $dd->{'subtype'} == 2 ) {
                            $networks->{$as} = { nets_v4 => [$net], nets_v6 => [] };
                        }
                        else {
                            $networks->{$as} = { nets_v6 => [$net], nets_v4 => [] };
                        }
                    }
                    else {

                        if ( $dd->{'subtype'} == 2 ) {
                            push @{ $networks->{$as}->{'nets_v4'} }, $net;
                        }
                        else {
                            push @{ $networks->{$as}->{'nets_v6'} }, $net;
                        }
                    }
                }
            }
        }
    }
}

# Now roughly detect countries
foreach my $u ( @{ $config{'asn_sources'} } ) {
    my $parsed = URI->new($u);
    my $fname  = $download_target . '/' . basename( $parsed->path );
    open( my $fh, "<", $fname ) or die "Cannot open $fname: $!";

    while (<$fh>) {
        next if /^\#/;
        chomp;
        my @elts = split /\|/;

        if ( $elts[2] eq 'asn' && $elts[3] ne '*' ) {
            my $as_start = int( $elts[3] );
            my $as_end   = $as_start + int( $elts[4] );

            for ( my $as = $as_start ; $as < $as_end ; $as++ ) {
                my $real_as = $as;

                if ( ref($as) eq "ARRAY" ) {
                    $real_as = @{$as}[0];
                }

                if ( $networks->{"$real_as"} ) {
                    $networks->{"$real_as"}->{'country'} = $elts[1];
                    $networks->{"$real_as"}->{'rir'}     = $elts[0];
                }
            }
        }
    }
}

while ( my ( $k, $v ) = each( %{$networks} ) ) {
    if ($v4) {
        foreach my $n ( @{ $v->{'nets_v4'} } ) {

            # "15169 | 8.8.8.0/24 | US | arin |" for 8.8.8.8
            if ( $v->{'country'} ) {
                printf $v4_fh "%s %s|%s|%s|%s|\n", $n, $k, $n, $v->{'country'}, $v->{'rir'};
            }
            else {
                printf $v4_fh "%s %s|%s|%s|%s|\n", $n, $k, $n, 'UN', 'UN';
            }
        }
    }
    if ($v6) {
        foreach my $n ( @{ $v->{'nets_v6'} } ) {

            # "15169 | 8.8.8.0/24 | US | arin |" for 8.8.8.8
            if ( $v->{'country'} ) {
                printf $v6_fh "%s %s|%s|%s|%s|\n", $n, $k, $n, $v->{'country'}, $v->{'rir'};
            }
            else {
                printf $v6_fh "%s %s|%s|%s|%s|\n", $n, $k, $n, 'UN', 'UN';
            }
        }
    }
}

__END__

=head1 NAME

asn.pl - download and parse ASN data for Rspamd

=head1 SYNOPSIS

asn.pl [options]

 Options:
   --download-asn         Download ASN data from RIR
   --download-bgp         Download GeoIP data from Maxmind
   --target               Where to download files (default: current dir)
   --zone-v4              IPv4 zone (default: asn.rspamd.com)
   --zone-v6              IPv6 zone (default: asn6.rspamd.com)
   --file-v4              IPv4 zone file (default: ./asn.zone)
   --file-v6              IPv6 zone (default: ./asn6.zone)
   --help                 Brief help message
   --man                  Full documentation

=head1 OPTIONS

=over 8

=item B<--download-asn>

Download ASN data from RIR.

=item B<--download-bgp>

Download GeoIP data from Ripe

=item B<--target>

Specifies where to download files.

=item B<--help>

Print a brief help message and exits.

=item B<--man>

Prints the manual page and exits.

=back

=head1 DESCRIPTION

B<asn.pl> is intended to download ASN data and GeoIP data and create a rbldnsd zone.

=cut