lightunneld

#!/usr/bin/perl
# 
# lightunneld.pl
#
# Author: Liraz Siri <liraz@hushmail.com>
# 
# Copyright (c) 1998 Liraz Siri <liraz@hushmail.com> Ariel, Israel
#		All rights reserved.
#
# Created: Tue Oct 20 11:19:47 IST 1998
#
# Lightunneld is the server side of the lightunnel package. This is VERY
# simple, and could be done just as easily using netcat. This isn't even
# very compact as there should be little reason to try to execute it from
# command line like several other parts of the lightgate project.
#
# Use is simple:
# lightunneld [port]
#
# Note: by default we bind to port 80.

use Socket;
my $listen_port;

$listen_port = 80;
$listen_port = int($ARGV[0]) if($ARGV[0]);

socket(SOCK, AF_INET, SOCK_STREAM, 0);
bind(SOCK, sockaddr_in($listen_port, INADDR_ANY)) || 
 die "Error: failed binding socket to port $listen_port\n";

listen(SOCK, 1);

printf(STDERR "Waiting for incoming connection on port %d...\n", $listen_port);

my ($rport, $raddr) = sockaddr_in(accept(NEWSOCK, SOCK));
my $hostname = gethostbyaddr($raddr, AF_INET);
$hostname eq "" && ($hostname = "unresolved");

printf(STDERR "Connection from %s (%s):%d received... begin session\n", 
       hostname, inet_ntoa($raddr), $rport);

close(SOCK);

my ($readfds, $bytes, $stdin_buffer);

vec($readfds, fileno(NEWSOCK), 1) = 1;
vec($readfds, fileno(STDIN), 1) = 1;


for(;;) {
 next if(!select($rs = $readfds, undef, undef, undef));
 if(vec($rs, fileno(STDIN), 1) == 1) {
  $bytes = sysread(STDIN, $stdin_buffer, 1024);
  syswrite(NEWSOCK, $stdin_buffer, $bytes); 
 } 

 if(vec($rs, fileno(NEWSOCK), 1) == 1) {
  if(!($bytes = sysread(NEWSOCK, $stdout_buffer, 1024))) 
  {
   die "Connection reset by remote host.\n";
  }
  syswrite(STDOUT, $stdout_buffer, $bytes);
 } 
}