icmp_socket = socket_create(af_inet, sock_raw, 1);
   socket_set_block($this->icmp_socket);
  }
function ip_checksum($data)
  {
     for($i=0;$i     {
         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 will have to work with this later
   $sqn = \x00\x00; // we will 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    if ((int)$percision   
   // set the timeout
   socket_set_option($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->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;
$ping->ping(www.google.ca);
if ($ping->time)
  echo time: .$ping->time;
else
  echo $ping->errstr;