#!/usr/local/bin/perl
 
use Net::Telnet ();
use MIME::Base64 ();
use Sys::Syslog qw(:DEFAULT setlogsock);
use IO::Socket;

# YOUR hn.org name and password go here.
$username = "xxxxxxxx";
$password = "yyyyyyyy";

my ($RouterAddr, $RouterName, $RouterPass);

$RouterName     = 'zzzzzzzz';
$RouterAddr     = 'aaa.bbb.ccc.ddd';
$RouterPass     = '********';

$logfile        = '/var/log/hn-tx4l.log';

sub GetRouterInfo{

  my(@lines);  
  $t = new Net::Telnet ( Timeout => 10 );
  $t->open($RouterAddr);
  $t->waitfor('/Password:.*$/');
  $t->print($RouterPass);
  $t->waitfor('/Number:.*$/');
  $t->print("24");
  $t->waitfor('/Number:.*$/');
  $t->print("8");
  
  $t->prompt("/$RouterName\> /");
  my @cmd = ("ip ifconfig enif1", "exit");

  foreach(@cmd){
    push(@lines, $t->cmd("$_"));
  }

  $t->waitfor('/Number\:.*$/');
  $t->print("99");

  $t->close;

  return(@lines); 

}

sub GetRouterAddr{
  my($ip);
  my(@info) = &GetRouterInfo;
  foreach(@info){
    if (/inet\s*(\d*\.\d*\.\d*\.\d*)\,/) {
      $ip = $1;
      last;
    }
  }
  return($ip);
}

sub OldIp{
  open(LOG, "$logfile") || die("Can't open $logfile :$!\n");
  my @lines = <LOG>
  close(LOG);
  my($ti, $ip);
  $ip = 'nodata';
  foreach(@lines){
    if (/^(\d*)\s\[.*\]\s(\d*\.\d*\.\d*\.\d*)$/) {
      $ti = $1; $ip = $2;
      last;
    }
  }
  return($ti, $ip);
}

sub Write{
  my($ti, $dt, $ip) = @_;
  open(LOG, "$logfile");
  my @lines = <LOG>
  close(LOG);
  unshift(@lines, "$ti [$dt] $ip\n");
  open(LOG, ">$logfile");
  print LOG @lines;
  close(LOG);
}  

sub GetDateTime{
  my $ti = time;
  my @t = localtime($ti);
  my @z = ('00' .. '99', '00' .. '99');
  my $dt="$z[$t[5]]/$z[$t[4]+1]/$z[$t[3]] $z[$t[2]]:$z[$t[1]]:$z[$t[0]]";
  return($ti, $dt);
}

### MAIN ###

($sec, $datetime) = &GetDateTime;

$myip = &GetRouterAddr;

print "$sec [$datetime] $myip\n";

($oldsec, $oldip) = &OldIp;

if ($oldip eq "nodata"){
  print "This is the first try! Effective from next time.\n";
  &Write($sec, $datetime, $myip);
  exit;
}
elsif ($myip eq $oldip){
  if ($sec - $oldsec > 2592000) {
    print "30 days from the last updating. HN is accessed.\n";
    &Write($sec, $datetime, $myip);
  } else {
    print "Ok. Ip address has not changed.\n";
    exit;
  }
} else {
  print "IP address had changed. HN is accessed.\n";
  &Write($sec, $datetime, $myip);
}

### hammernode.pl start ###

# If you're behind a firewall or HTTP proxy, set this to 1.
# If you're not sure, set it to 1; that's the safer setting anyway.
# If you KNOW you're not behind a firewall or proxy, set to 0.
$firewall = 1;

# Okay, that's all you'll need to configure *here*. You're not done,
# though... You still need to configure this to run automatically, and to
# use the correct IP address. For Linux users with pppd, the easiest way
# to put a line like this in /etc/ppp/ip-up :
#
#            /usr/local/sbin/hammernode.pl $4
#
# If that doesn't make much sense, see `man pppd' which details what
# parameters pppd sends to ip-up.
#
# A clever trick for dhcpcd users... put this in your
# /etc/dhcpcd/dhcpcd-eth0.exe file:
#
# source /etc/dhcpc/dhcpcd-eth0.info && /usr/local/sbin/hammernode.pl $IPADDR
#
# (I discovered this was necessary -- my cable modem company puts an
# "invisible" HTTP proxy in between me and the 'net, and my domains were
# being assigned the address of the proxy.
#
# (C)2000-2001 David E. Smith <dave@bureau42.com> and released to the
#  public under the terms of the GNU General Public License.
#
# Modified by Daniel Hagan <dhagan@colltech.com> on 4/2001 to use IO::Socket,
# Syslog, and some error checking.  Now logs all output to daemon facility.
#
# Other changes made/suggested by Aurelien Beaujean <aure@dagobah.eu.org>
# Sorry, but I can't type the accent over the first "e" in Aurelien.
#
###############

# If you don't let syslogd listen on an inet port, uncomment this line.
#
#setlogsock 'unix';

openlog ("hammernode", 'pid', 'daemon');

#$myip = shift;

if ($firewall && !$myip) {
        syslog ('err', "FATAL: IP required as command line argument when \$firew
all is set to true.");
        exit(1);
}

$target = "dup.hn.org";
$version = "v0.22pl0";
$pass = MIME::Base64::encode_base64("$username:$password");

if ($firewall == 1) {
        $url = "/vanity/update/?VER=1&IP=$myip" ;
} else {
        $url = "/vanity/update/?VER=1" ;
}

syslog ('info', 'Setting domain to %s.', $myip);
$sock = new IO::Socket::INET(
        PeerAddr => "$target",
        PeerPort => 'http(80)'
);

if (!$sock) {
        syslog('err', "FATAL: Connect to $target, port 80, failed: %m");
        exit(1);
}

$sock->autoflush(1);

$sock->print("GET $url HTTP/1.0\r\n");
$sock->print("User-Agent: hammenode.pl $version\r\n");
$sock->print("Host: $target\r\n");
$sock->print("Authorization: Basic $pass\r\n\r\n");

# Legacy sleep from v0.21pl2.  May be necessary on some slow PC platforms.
# If you are having problems, try uncommenting this first.
#
#sleep 5;

@result = $sock->getlines();

undef $sock; #Close the socket

$result = join '', @result;
$result =~ m/DDNS_Response_Code=(\d+)/i;
$code = $1;

if ($code == 101) {
        syslog ('info', "Succeeded in setting domain to $myip.");
        exit(0);
} else {
        syslog ('notice', "Received DDNS Reponse Code $code, probably failed.");
        exit(1);
}