#! @PATH_PERL@ -w
# John Hay -- John.Hay@icomtek.csir.co.za / jhay@FreeBSD.org

package ntptrace;
use 5.006_000;
use strict;
use lib "@PERLLIBDIR@";
use NTP::Util qw(ntp_read_vars do_dns);

exit run(@ARGV) unless caller;

sub run {
    my $opts;
    if (!processOptions(\@_, $opts)) {
        usage(1);
    };

    my $dodns     = $opts->{numeric} ? 0 : 1;
    my $max_hosts = $opts->{'max-hosts'};
    my $host      = shift || $opts->{host};
    my $nb_host   = 0;

    for (;;) {
        $nb_host++;

        my %info = get_info($host);
        last if not %info;

        my $dhost = $host;
        if ($dodns) {
            my $name = do_dns($host);
            $dhost = $name if defined $name;
        }

        printf "%s: stratum %d, offset %f, synch distance %f",
            $dhost, $info{stratum}, $info{offset}, $info{syncdistance};
        printf ", refid '%s'", $info{refid} if $info{stratum} == 1;
        print "\n";

        last if $info{stratum} == 0 || $info{stratum} == 1 || 
                $info{stratum} == 16;
        last if $info{refid} =~ /^127\.127\.\d{1,3}\.\d{1,3}$/;
        last if $nb_host == $max_hosts;

        my $next_host = get_next_host($info{peer}, $host);
        last if $next_host eq '';
        last if $next_host  =~ /^127\.127\.\d{1,3}\.\d{1,3}$/;

        $host = $next_host;
    }
    return 0;
}

sub get_info {
    my ($host) = @_;
    my ($rootdelay, $rootdisp, $info) = (0, 0);

    $info = ntp_read_vars(0, [], $host);
    return if not defined $info;
    return if not exists $info->{stratum};

    $info->{offset} /= 1000;
    $info->{syncdistance} = ($info->{rootdisp} + ($info->{rootdelay} / 2)) / 1000;

    return %$info;
}


sub get_next_host {
    my ($peer, $host) = @_;

    my $info = ntp_read_vars($peer, [qw(srcadr)], $host);
    return if not defined $info;
    return $info->{srcadr};
}

@ntptrace_opts@

1;
__END__
