#!/usr/bin/perl -w 

use strict;
use Device::SerialPort;
use ControlX10::CM11;
use Net::Ping;
use Net::Syslog;
use POSIX;

# DAEMON stuff
my $pid=fork;
exit if $pid;
die "Couldn't fork: $!" unless defined $pid;

POSIX::setsid() or die "Can't start a new session: $!";
# end DAEMON stuff

my $s=new Net::Syslog(Facility=>'local5', Priority=>'notice',
        Name=>'dslmonitor');

$SIG{TERM}=sub {
  $s->send('DSL monitoring stopping');
  exit;
};


$s->send('DSL monitoring started');
my $i;
my $m;
my $ctr=0;
my $tdown;
while(1){
  $m=is_modem_up();
  if(!$m){
    $s->send("modem not responding to ping");  
  }
  $i=is_internet_up() if(($ctr==0)||(!$m));
  if((!$i)||(!$m)){
    $s->send('lost internet connection');
    $tdown=time();
  }
  while((!$i)||(!$m)){
    $s->send('stopping pppoe');
    stop_pppoe();
    $m=0;
    while(!$m){
      $s->send('power cycling DSL modem');
      power_cycle_modem();
      $s->send('power cycling complete, waiting for modem to respond to ping');
      my $b=time;
      my $tdiff=time()-$b;
      while(($tdiff<30)&&(!$m)){
        sleep 1;
        $m=is_modem_up();
        $tdiff=time()-$b;
      }
      if($m){
        $s->send("modem up $tdiff sec after cycle\n");
      }else{
        $s->send("modem not responding to pings $tdiff seconds after reboot, power cycle modem again");
      }
    }  
    $s->send("waiting 30 seconds for modem DSL negotiation to occur");
    sleep 30;
    $s->send("starting pppoe");
    start_pppoe();
    $s->send("pppoe start complete, waiting 5 seconds");
    sleep 5;   
    $s->send("probing for connectivity");
    $i=is_internet_up();  
    $m=is_modem_up();
    if(!$m){
      $s->send("modem not responding to ping");  
    }
    if(($i)&&($m)){
      $tdown=time()-$tdown;
      my $se=$tdown%60;
      my $m=(int($tdown/(60)))%60;
      my $h=(int($tdown/(60*60)))%24;
      my $d=(int($tdown/(60*60*24)));
      $s->send("internet connection restored after $d days, $h hours, $m minutes and $se seconds of downtime"); 
    }else{
      $s->send("pppoe negotiation failed");
    }
  }
  sleep 30;
  $ctr=($ctr+1)%10;
}


sub is_modem_up{
  my $p=new Net::Ping("icmp");
  for(my $c=0;$c<3;$c++){
    my $i=$p->ping('10.0.0.1',2);;
    return $i if($i);
  }
  return 0;
}


sub is_internet_up{
  my $p=new Net::Ping("icmp");
  my @inethosts=('192.5.5.241','202.12.27.33','128.63.2.53');
  for(my $c=0;$c<3;$c++){
    foreach(@inethosts){
      my $i= $p->ping($_,5);
      return $i if($i);
    }
  }
  $s->send("internet not responding to ping"); 
  return 0;
}


sub stop_pppoe{
  system '/etc/rc.d/init.d/adsl stop >/dev/null 2>/dev/null';
}



sub start_pppoe{
  system '/etc/rc.d/init.d/adsl start >/dev/null 2>/dev/null';
  # checking output would be a good idea
}



sub power_cycle_modem{
  #my $serial_port = new Device::SerialPort('/dev/x10');
  my $serial_port = new Device::SerialPort('/dev/ttyS0');
  if(!defined $serial_port){
    die "error openign serial \"$!\"";
  }

  $serial_port->baudrate(4800);
  $serial_port->databits(8);
  $serial_port->parity('none');
  $serial_port->stopbits(1);
  $serial_port->handshake('none');
  $serial_port->stty_echo(0);

  $serial_port->read_const_time(5000);
  $serial_port->read_char_time(5);


  &ControlX10::CM11::send($serial_port, 'B1'); 
  &ControlX10::CM11::send($serial_port, 'BK'); 

  sleep 5;

  &ControlX10::CM11::send($serial_port, 'B1'); 
  &ControlX10::CM11::send($serial_port, 'BJ'); 
}