#!/usr/bin/perl

use warnings;
use strict;

use STUN::RFC_5389;
use Socket;

die "$0 <server> [port]\n" unless $#ARGV >= 0;
my ($server,$port) = @ARGV;
$port = $port // 3478;

$|=1;

my $request = Client STUN::RFC_5389 { request => 1 };
my $lport = 10000+(int rand 55536);

my $lpaddr = sockaddr_in($port, inet_aton("0.0.0.0")) || die "sockaddr_in: $!\n";
print "socket: ";
socket(SOCKET, PF_INET, SOCK_DGRAM, getprotobyname("udp")) && print "\n" || die "$!\n";
print "bind: ";
bind(SOCKET, $lpaddr) && print "\n" || die "$!\n";

my $siaddr = inet_aton($server) || die "inet_aton: $!\n";
my $spaddr = sockaddr_in($port, $siaddr) || die "sockaddr_in: $!\n";
print "send: ";
defined(send(SOCKET, 0, 0, $spaddr)) && print "\n" || die "$!\n";

my $response;
print "recv: ";
recv(SOCKET, $response, 1024, 0) && print "\n" || die "$!\n";

my $mapped_address = ${Client STUN::RFC_5389 $response}{attributes}->{'MAPPED-ADDRESS'};
print $mapped_address->{address},":",$mapped_address->{port},"\n";

print "Listening\n";
my $buf;
$|=1;
while (recv(SOCKET,$buf,1,0)) { print $buf }
die "recv: $!\n";