#!/usr/bin/perl ########################################## # #

by phil on Wednesday Jul 30, 2003 12:29 AM 

#!/usr/bin/perl


##########################################

#

# Flash sometimes has problems communicating

# to traditional TCP/IP XML servers.  This is

# is because each packet that the Flash clients

# print to servers are ended by a "\0" while as

# server's traditionally recognize "\n" as the

# end.  Example, in Perl, if you go $line = 

# $line will usually contain one line of the file

# where a line is whatever's delimited by \n's.

# Also, when reading data back, Flash only

# recognizes data if it's delimited by "\0"'s as

# well.  Lame, I know.

# 

# This program relays communication back

# and forth between flash clients and standard

# servers.  There is an XML parsing issue that

# also has to be taken into account as each

# XML packet that comes from the server needs

# to be delimited with \0's.  I've attempted

# to take care of this as you'll see below..

# it hasn't been rigorously tested though

# so use at your own risk...

#

# I'm not the greatest programmer, and there

# may be blocking issues... so, please improve.

#

# I got most of this junk from Advanced Perl

# Programming by O'Reilly.

#

# - Philip Dhingra (philipd@stanford.edu)

#   http://www.philosophistry.com/

#

# Keywords: XMLSocket

###########################################



use IO::Socket;

use IO::Select;



$remote_rs = "\n";

$flash_rs = "\0";



# XML tags that I want to be sent to Flash

@root_headers = ('Q','O','M');



# $/ denotes the input record separator (default: '\n')

# $\ denotes the output record separater (default: null)

# Flash separates records with a \0

# Standard TCP/IP servers use the default, \n



close STDOUT; # if you don't want to see what's going on



$remote_host = 'whatever.com';

$remote_port = '6969';



$local_port = '9696';





$flash_sock = new IO::Socket::INET (Listen		=> SOMAXCONN,

									Proto		=> 'tcp',

									Reuse		=> 1,

									LocalPort	=> $local_port)

				or die ("**STATUS: Flash Listening Server could not start");

			

sub open_remote_sock {



	return new IO::Socket::INET (Proto		=> 'tcp',

								 PeerAddr	=> $remote_host,

								 PeerPort	=> $remote_port)

			or die ("**STATUS: Cannot Connect to Remote Server (" . $remote_host . ":" . $remote_port);



}



print "**STATUS: Flash Listening Server started\n" if ($flash_sock);

				

$read_set = new IO::Select;

$read_set->add($flash_sock);



while(1) {

	($new_readable) = IO::Select->select($read_set, undef, undef, undef);

	

	foreach $readable (@$new_readable) {

		if ($readable == $flash_sock) {

			$flash_client = $flash_sock->accept();



			$read_set->add($flash_client);

			

			print "**STATUS: Flash connection from: " . $flash_client->peerhost . "\n";



			$read_set->add($remote_sock = &open_remote_sock);

			print "**STATUS: Connected to Remote Server\n" if ($remote_sock);



		} elsif ($readable == $remote_sock) {

			$/ = $remote_rs;

			$from_remote = <$remote_sock>;

			chomp $from_remote;





			if ($from_remote eq '') {

				print "**STATUS: Remote Server connection lost**";

				$remote_sock->close;

				exit;				

			} else {

				print "(-): " . $from_remote . "\n";



				# BEGIN XML parsing..



				if ($waiting_for) {

					$queue .= $from_remote;

				} else {

					$queue = $from_remote;

				}



				$waiting_for = hasRootHeaders($from_remote) unless ($waiting_for);



				if ($waiting_for) {

					if ($queue =~ s/(<$waiting_for>.*?<\/$waiting_for>)//s) {



						print $flash_client $1 . $flash_rs;

						$flash_client->flush();



						$waiting_for = hasRootHeaders($queue);

					}

				}



				# END XML parsing



			}



		# Flash client is trying to speak...

		} elsif ($readable == $flash_client) {

			$/ = $flash_rs;

			$from_flash = <$readable>;

			chomp($from_flash);

			

			if ($from_flash eq '') {

				print "**STATUS: Connection to Flash Client (" . $flash_client->peerhost . ") lost\n";

				$read_set->remove($readable);

				$readable->close;



				# closing remote socket

				$read_set->remove($remote_sock);

				$remote_sock->close;

			} else {

			

				print "(+): " . $from_flash . "\n";

				print $remote_sock $from_flash . $remote_rs;

				$remote_sock->flush();



			}



		# Dead client is trying to speak

		} else {

			print "**STATUS: Connection to Flash Client (" . $readable->peerhost . ") lost\n";

			$read_set->remove($readable);

			$readable->close;

			

			# closing remote socket

			$read_set->remove($remote_sock);

			$remote_sock->close;

		}

	}

}





sub hasRootHeaders {

	my $snippet = shift;

	my @matches;



	foreach $key (@root_headers) {

		if ($snippet =~ m##) {

			$tail_key = $key;

		}

	}

	

	foreach $key (@root_headers) {

		if ($snippet =~ m#<$key>#) {

			push @matches, $key;

		}

	}

	foreach $match (@matches) {

		return $match if ($match eq $tail_key);

	}



	return pop(@matches) if (@matches);

	

	return '';

}



sub drainReadBuffer {

	my $sock = shift;

	my $bytes_to_read = 1024;

	my $msg;



	



}

Keywords: flash, record separator, null terminator, xmlsocket, xml server, relay

Comments

majid khossravi said on February 22, 2004 6:49 AM:

how swf file within a html can communicate this server , i mean XMLSocket connection doesnt work if i wont execute perl file befor


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