Using Sockets in PHP

<?php

Class Net_ping
{
var $icmp _socket;
var $request;
var $request _len;
var $reply;
var $errstr;
var $time;
var $timer _start_time;
function net_ping ()
{
$this->icmp_socket = socket_create (Af_inet, Sock_raw, 1);
Socket_set_block ($this->icmp_socket);
}

function Ip_checksum ($data)
{
for ($i =0; $i <strlen ($data); $i + + 2)
{
if ($data [$i +1]) $bits = unpack (' n ', $data [$i]. $data [$i +1]);
else $bits = unpack (' c* ', $data [$i]);
$sum + + $bits [1];
}

while ($sum >>16) $sum = ($sum & 0xffff) + ($sum >> 16);
$checksum = Pack (' n1 ', ~ $sum);
return $checksum;
}

  function start_time ()
  {
   $this->timer_start_time = Microtime ();
 

 
  function get_time ($ACC =2)
  {  //Format start time
    $start _time = Explode ("", $this->timer_start_time);
   $start _time = $start _time[1] + $start _time[0];
  /Get and format end time
   $end _time = Explode ("", Microtime ());
   $end _time = $end _time[1] + $end _time[0];
   return Number_format ($end _time-$start _time, $ACC);
 }

function Build_packet ()
{
$data = "Abcdefghijklmnopqrstuvwabcdefghi"; The actual test data
$type = "\x08"; 8 echo message; 0 Echo Reply message
$code = "\x00"; Always 0 for this program
$CHKSM = "\x00\x00"; Generate checksum for ICMP request
$id = "\x00\x00"; We'll have to work with this later
$SQN = "\x00\x00"; We'll have to work with this later

Now we need to change the checksum to the real checksum
$CHKSM = $this->ip_checksum ($type. $code. $chksm $id. $sqn. $data);

  //Now lets build the actual ICMP packet
   $this->request = $type. $code. $chksm. $id. $sqn. $data;
   $this->request_len = strlen ($this->request);
 }
 
  function Ping ($dst _addr, $timeout =5, $percision =3)
  {
  //Lets catch dumb People
   if ((int) $timeout <= 0) $timeout =5;
   if ((int) $percision <= 0) $percision = 3;
  
  //Set the timeout
   socket_set_option ($this->icmp_socket,
     sol_socket, //SOCKET level
     So_rcvtimeo,//timeout option
     Array (
       "SEC" => $timeout,//timeout in Seconds
       "usec" =>0 //I assume timeout in microseconds
       )
    );

if ($DST _addr)
{
if (@socket_connect ($this->icmp_socket, $dst _addr, NULL))
{

} else {
$this-&GT;ERRSTR = "Cannot connect to $DST _addr";
return FALSE;
}
$this->build_packet ();
$this->start_time ();
Socket_write ($this->icmp_socket, $this->request, $this->request_len);
if (@socket_recv ($this->icmp_socket, & $this->reply, 256, 0))
{
$this->time = $this->get_time ($percision);
return $this->time;
} else {
$this->errstr = "Timed out";
return FALSE;
}
} else {
$this->errstr = "Destination address not specified";
return FALSE;
}
}
}

$ping = new Net_ping;
$ping->ping ("<a href=" http://www.google.ca "target=_blank>www.google.ca</a>");

if ($ping->time)
echo "Time:". $ping->time;
Else
Echo $ping->errstr;