<?php
##
## this file name is 'class.google.php'
##
## ping object
##
## [author]
##  - san2(at)cdnetworks.co.kr
##
## [changes]
##  - 2008.12.05 : add more
##  - 2008.12.01 : new build
##
## [references]
##  - http://kr.php.net/manual/en/function.socket-create.php
##  - http://ftp.linuxchannel.net/devel/php_download/
##
## [usage]
##
## [example]
##
class google
{
  ## googel network latency
  ##
  public function &ping($host)
  {
	static $port = 0;
	static $datasize = 58; // default 58 bytes + 8 = 64 bytes
	static $timeout = array('sec'=>0,'usec'=>500000);

	$ident = array(ord('J'), ord('C'));
	$seq = array(rand(0,255), rand(0,255));

	## 8 bytes of ICMP header data
	$packet = '';
	$packet .= chr(8); // type = 8 : request
	$packet .= chr(0); // code = 0
	$packet .= chr(0); // checksum init
	$packet .= chr(0); // checksum init
	$packet .= chr($ident[0]); // identifier
	$packet .= chr($ident[1]); // identifier
	$packet .= chr($seq[0]); // seq
	$packet .= chr($seq[1]); // seq

	for($i=0; $i<$datasize; $i++) $packet .= chr(0);

	$chk = google::icmpchecksum($packet);

	$packet[2] = $chk[0]; // checksum init
	$packet[3] = $chk[1]; // checksum init

	if(preg_match('/[a-z]/',$host)) $host = gethostbyname($host); // to ip

	if(!$sock = @socket_create(AF_INET, SOCK_RAW, getprotobyname('icmp')))
	{
		return array(-1, socket_last_error());
	}

	@socket_set_option($sock,SOL_SOCKET,SO_RCVTIMEO,$timeout); // good idea for blocking mode
	@socket_set_option($sock,SOL_SOCKET,SO_SNDTIMEO,$timeout);

	$start = microtime();
	@socket_sendto($sock, $packet, strlen($packet), 0, $host, $port);

	$read   = array($sock);
	$write  = NULL;
	$except = NULL;
	$select = @socket_select($read, $write, $except, 0, 500000);

	if($select === NULL)
	{
		@socket_close($sock);
		return array(-1,'Select Error');
	}
	else if($select === 0)
	{
		@socket_close($sock);
		return array(-1,'Timeout');
	}

	$recv = '';
	@socket_recvfrom($sock, $recv, 65535, 0, $host, $port);
	$end = microtime();
	@socket_close($sock);

	$recv = unpack('C*', $recv);

	// ICMP proto = 1
	if($recv[10] !== 1) return array(-1,"Not ICMP packet");

	// ICMP response = 0
	if($recv[21] !== 0) return array(-1,"Not ICMP response");
	if($ident[0] !== $recv[25] || $ident[1] !== $recv[26]) return array(-1,"Bad identification number");
	if($seq[0] !== $recv[27] || $seq[1] !== $recv[28]) return array(-1,"Bad sequence number");

	$rtt = google::getms($start, $end);

	return array($rtt);
  }

  private function &icmpchecksum($data)
  {
	$bit = unpack('n*', $data);
	$sum = array_sum($bit);

	if (strlen($data) % 2)
	{
		$temp = unpack('C*', $data[strlen($data) - 1]);
		$sum += $temp[1];
	}

	$sum = ($sum >> 16) + ($sum & 0xffff);
	$sum += ($sum >> 16);

	return pack('n*', ~$sum);
  }

  ## google map loading server latency
  ## default non-blocking mode
  ##
  public function &gethttp($_url, $iporhost='')
  {
	static $bsize = 1048576; // socket send/receive buffer size(Bytes)
	static $timeout = array('sec'=>0,'usec'=>500000);
	static $port = 80;

	list($host,$ip,$uri) = google::gethostip($_url,$iporhost);

	if(!$sock = @socket_create(AF_INET, SOCK_STREAM, SOL_TCP))
	{
		return array(-1, socket_last_error());
	}

	@socket_set_option($sock,SOL_SOCKET,SO_SNDBUF,$bsize);
	@socket_set_option($sock,SOL_SOCKET,SO_RCVBUF,$bsize);
	@socket_set_option($sock,SOL_SOCKET,SO_RCVTIMEO,$timeout); // good idea for blocking mode
	@socket_set_option($sock,SOL_SOCKET,SO_SNDTIMEO,$timeout);

	@socket_set_nonblock($sock); // set to non-blocking mode

	$req = 'GET '.$uri.' HTTP/1.1'."\r\n".
		'Host: '.$host."\r\n".
		'User-Agent: PHP/google'."\r\n".
		'Connection: close'."\r\n". // good idea for blocking mode
		"\r\n"; // enf of request header mark

	$start = microtime();
	$code = google::_connect($sock,$ip,$port,5);
	if($code != 1)
	{
		@socket_close($sock);
		return array(-1, "can not connect to $ip:$port");
	}

	if(!@socket_write($sock,$req))
	{
		@socket_close($sock);
		return array(-1, "can not send request $uri");
	}

	$header = google::_getheader($sock,1024); // read header
	$header = google::_parse_header($header);
	if($header['error'])
	{
		@socket_close($sock);
		return array(-1, $header['status'].' '.$uri);
	}

	//$total = $header['content-length']; // total size
	//$pg = $debug ? $total : 0; // debug mode with progress

	$size = google::_readsize($sock,$bsize); // check bandwidth mode
	//google::_readbyall($sock,$buf='',$bsize,$blocking,$pg);
	//$size = strlen($buf);

	@socket_close($sock);
	$end = microtime();

	return array(google::getms($start,$end));
  }

  public function gethostip($_url, $iporhost='')
  {
	list($nhost,,$uri) = google::_parse_url($_url);

	if(preg_match('/[a-z]/',$nhost)) $host = $nhost;
	else $ip = $nhost;

	if($iporhost)
	{
		if(preg_match('/[a-z]/',$iporhost)) $host = $iporhost;
		else $ip = $iporhost;
	}

	if(!$ip) $ip = gethostbyname($host); // to ip
	else if(!$host) $host = $ip; // not good

	return array($host,$ip,$uri);
  }

  ## connect to host:port
  ##
  ## [return]
  ##  1 or TRUE  : connected
  ##  0 or FALSE : can't connect
  ##  -1         : connetion time out
  ##
  private function &_connect(&$sock, $host, $port, $timeout=3)
  {
	$_time = time();
	while(1)
	{
		@socket_connect($sock,$host,$port);
		if(@socket_last_error()==56 || @socket_last_error()==106) { return TRUE; break; }
		else if((time()-$_time) >= $timeout) { return -1; break; }
	}

	return FALSE;
  }

  ## read header by socket_read()
  ## PHP_NORMAL_READ : 1
  ## PHP_BINARY_READ : 2
  ##
  private function &__readheader(&$sock, $bsize)
  {
	while($buf = @socket_read($sock,$bsize,PHP_NORMAL_READ))
	{
		//if(!defined('_RESPONSE_END_')) define('_RESPONSE_END_',microtime());
		if(!trim($obuf.$buf))
		{
			@socket_read($sock,$bsize,PHP_NORMAL_READ); // seek 1 bytes
			break; // end of header
		}
		$rbuf .= $buf; 	$obuf = $buf;
	}

	return $rbuf;
  }

  ## read HTTP all headers
  ##
  private function &_getheader(&$sock, $bsize=1024)
  {
	$stream = array($sock);
	while(@socket_select($stream,$write=NULL,$except=NULL,0,500000) !== FALSE)
	{
		//if(!in_array($sock,$stream)) break; // is bug ???
		$rbuf = google::__readheader($sock,$bsize);
		break; // require
	}

	return $rbuf;
  }

  private function &_parse_header($buf)
  {
	$lines = preg_split('/[\r\n]+/',trim($buf));
	$size = sizeof($lines);
	$r['status'] = trim($lines[0]);

	if(!preg_match(';200 OK;',$lines[0]))
	{
		$r['error'] = TRUE;
		return $r;
	}

	for($i=1; $i<$size; $i++)
	{
		$line = trim($lines[$i]);
		list($k) = preg_split('/:\s+/',$line);
		$r[strtolower($k)] = preg_replace(';^'.$k.':\s+;','',$line);
	}

	return $r;
  }

  ## only read size, this is a bandwidth test version
  ##
  private function &_readsize(&$sock, $bsize=1048576)
  {
	$stream = array($sock);
	while(@socket_select($stream,$write=NULL,$except=NULL,0,500000) !== FALSE)
	{
		if(!in_array($sock,$stream)) break;
		if($tsize = strlen(@socket_read($sock,$bsize)))
		{
			$rsize += $tsize;
		} else break; // good idea, EOF
	}

	return $rsize;
  }

  private function &getms($_start, $_end)
  {
	$end = explode(' ', $_end);
	$start = explode(' ', $_start);

	return sprintf('%.3f',(($end[1]+$end[0])-($start[1]+$start[0])) * 1000);
  }

  private function &_parse_url($_url)
  {
	$url = parse_url(preg_replace(';^(?:http://)*;i','http://',trim($_url)));

	$host = $url['host'];
	$port = $url['port'] ? $url['port'] : 80;
	$uri = $url['path'] ? $url['path'] : '/';

	if($url['query']) $uri .= '?'.$url['query']; // add san2@2008.12.01

	return array($host,$port,$uri);
  }

  private function &error($errstr)
  {
	return error_log($errstr,0);
  }
} // end of class
?>