#!/usr/local/bin/perl
# Currently we only support ASCII

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

$BUFFSIZE = 1024;

%options = ();
$x = getopts( 's:d:h', \%options );

usage() if ( ( ! $options{ 's' } && ! $options{ 'd' } ) || $options{ 'h' } );
# Putting the data out the destination is just a print whether file, STDOUT,
#   or a socket.
$DST = setdestination( $options{ 'd' } );
( $SRC, $LMODE ) = setsource( $options{ 's' } );

# Depending on the source, we need different loop styles.
if ( $LMODE eq 'file' ) { # source data is a file or STDIN
    while ( sysread( $SRC, $buffer, $BUFFSIZE ) ) {
	syswrite( $DST, $buffer, $BUFFSIZE );
    }
    
    close( $DST );
    close( $SRC );
    exit;
}

# If source is not file or STDIN, must be a socket.  But I
#  only know of different ways to handle tcp and udp.
if ( $LMODE eq 'tcp' ) {
    while ( $new_socket = $SRC -> accept() ) {
	while ( sysread( $new_socket, $buffer, $BUFFSIZE ) ) {
	    syswrite( $DST, $buffer, $BUFFSIZE );
	}
    }
    close( $DST );
    close( $SRC );
} else {
    $selects = new IO::Select();
    $selects -> add( $SRC );
    while ( 1 ) {
	foreach $server ( $selects -> can_read( 60 ) ) {
	    $server -> recv( $buffer, $BUFFSIZE );
	    syswrite( $DST, $buffer, $BUFFSIZE );
	}
    }
    close( $DST );
    close( $SRC );
}


sub setsource {
    my ( $source ) = $_[0];
    my ( $ip, $port, $proto );
    my $result, $lmode;

    $lmode = 'file';
    if ( ! $source ) {
	$result = STDIN;
    } elsif ( $source =~ /\:[0-9]+\// ) {
	( $ip, $port, $proto ) = $source =~ /^([^:]+):([0-9]+)\/(.+)$/;
	$lmode = $proto;
	if ( $proto =~ /tcp/ ) {
	    $result = new IO::Socket::INET( LocalHost => $ip,
					 LocalPort => $port,
					 Reuse     => 1,
					 Listen    => 5 );
	    if ( ! $result ) {
		print "Unable to create socket: $!\n...Terminating.\n\n";
		exit;
	    }
	} else {
	    $result = new IO::Socket::INET( LocalHost => $ip,
					 LocalPort => $port,
					 Proto     => $proto );
	    if ( ! $result ) {
		print "Unable to create socket: $!\n...Terminating.\n\n";
		exit;
	    }
	}
    } else {
	open( F, $source ) or do {
	    print "Unable to read $source...terminating.\n";
	    exit;
	};
	$result = F;
    }
    return ( $result, $lmode );
}

sub setdestination {
    my ( $destination ) = $_[0];
    my ( $ip, $port, $proto, $filename );
    my $result;

    if ( ! $destination ) {
	$result = STDOUT;
    } elsif ( $destination =~ /\:[0-9]+\// ) {
	( $ip, $port, $proto ) = $destination =~ /^([^:]+):([0-9]+)\/(.+)$/;
	$result = new IO::Socket::INET( PeerAddr => $ip,
				     PeerPort => $port,
				     Proto    => $proto );
	if ( ! $result ) {
	    print "Socket could not be created: $!\n...Terminating.\n\n";
	    exit;
	}
    } else {
	open( F, ">$destination" ) or do {
	    print "Unable to write $destination...terminating\n";
	    exit;
	};
	$result = F;
    }
    return $result;
}

sub usage {
    print qq{
Usage: $0 {options}

  -s [host:port/proto|filename]  : Set source (STDIN)
  -d [host:port/proto|filename]  : Set destination (STDOUT)


};
    exit;
}