#!/usr/bin/perl
#
# yet another script to find out my own ip number
# across routers and masquerades
#
# this uses tcp, but in this case udp would be smarter
# for a short timeout in case of offlinitis. also it could
# poll several servers at once to not be dependent on just one.
#
#$ask = 'beta.ve.symlynX.com';
$ask = 'psyced.org';
$port = 4404;

use Getopt::Std;
use IO::Socket;

getopt('HP', \%o);

$ask = $o{H} if $o{H};
$port = ${P} if $o{P};

# tried to multiplex -h <host> and -h as in --help, but it doesn't work
# getopt doesn't let me do a defined($o{h}) &&! $o{h} ...
# well it was just a perl exercise anyway
if ( $o{h} or $o{x} or $o{v} or $#ARGV >= 0 ) {
	print <<X;
Usage: $0 [ -H <host> ] [ -P <port> ] [ -n ] [ --help ]

Find out my public IP number by asking $ask
on port $port or anyone you provide using the -H and -P flags.
psycip looks for a _target* in the PSYC server greeting message.
Use -n if the hostname is okay, otherwise the IP will always be returned.
X
	exit;
}

$S = IO::Socket::INET -> new(
	PeerAddr => $ask,
	PeerPort => $port,
	Proto	 => 'tcp'
);

die $! unless $S;

print $S <<X;
.
X

while(<$S>) {
#	print "*** $_";
	if (m!^._target\w*\s+psyc://([^/:]+)/?!) {
		$_ = $1;
		s/\:\d*\w*$//;
		chomp;
		if ( $o{n} ) {
			print "$_\n";
			exit;
		}
		$_ = inet_ntoa($addrs[0]) if
		    ($name,$aliases,$addrtype,$length,@addrs)
		      = gethostbyname($_);
		print "$_\n";
		# close socket properly - avoid error messages ...
		# this shouldn't be necessary for short-lived things
		# so psyced needs to become smarter about it
		print $S <<X;

_request_circuit_shutdown
,
X
	}
}