珊瑚虫IP库浅析

这不是什么新鲜事情了，很早之前就已经有人做出来了。
就是使用PHP操作纯真IP库或珊瑚虫IP库，根据来访者的IP得到所在的物理位置。

我先帖出代码。然后再慢慢一步步浅析出来。希望对想了解这一块的朋友们有帮助。

Only For PHP5的代码。会继续优化代码的。

class IpLocation{
private $fp;
private $wrydat;
private $wrydat_version;
private $ipnumber;
private $firstip;
private $lastip;
private $ip_range_begin;
private $ip_range_end;
private $country;
private $area;
const REDIRECT_MODE_0 = 0;
const REDIRECT_MODE_1 = 1;
const REDIRECT_MODE_2 = 2;
function construct(){
$args = func_get_args();
$this->wrydat = func_num_args()>0?$args[0]:'CoralWry.dat';
$this->initialize();
}
function destruct(){
fclose($this->fp);
}
private function initialize(){
if(file_exists($this->wrydat))
$this->fp = fopen($this->wrydat,'rb');
$this->getipnumber();
$this->getwryversion();
}
public function get($str){
return $this->$str;
}
public function set($str,$val){
$this->$str = $val;
}
private function getbyte($length,$offset=null){
if(!is_null($offset)){
fseek($this->fp,$offset,SEEK_SET);
}
$b = fread($this->fp,$length);
return $b;
}
/**

• 把IP地址打包成二进制数据，以big endian（高位在前）格式打包

• 数据存储格式为 little endian（低位在前） 如：

• 00 28 C6 DA 218.198.40.0 little endian

• 3F 28 C6 DA 218.198.40.0 little endian

• 这样的数据无法作二分搜索查找的比较，所以必须先把获得的IP数据使用strrev转换为big endian

• @param $ip

• @return big endian格式的二进制数据
  */
  private function packip($ip){
  return pack( "N", intval( ip2long( $ip)));
  }

  private function getlong($length=4, $offset=null){
  $chr=null;
  for($c=0;$length%4!=0&&$c<(4-$length%4);$c++){
  $chr .= chr(0);
  }
  $var = unpack( "Vlong", $this->getbyte($length, $offset).$chr);
  return $var['long'];
  }

  private function getwryversion(){
  $length = preg_match("/coral/i",$this->wrydat)?26:30;
  $this->wrydat_version = $this->getbyte($length, $this->firstip-$length);
  }

  private function getipnumber(){
  $this->firstip = $this->getlong();
  $this->lastip = $this->getlong();
  $this->ipnumber = ($this->lastip-$this->firstip)/7+1;
  }

  private function getstring($data="",$offset=null){
  $char = $this->getbyte(1,$offset);
  while(ord($char) > 0){
  $data .= $char;
  $char = $this->getbyte(1);
  }
  return $data;
  }

  private function iplocaltion($ip){
  $ip = $this->packip($ip);
  $low = 0;
  $high = $this->ipnumber-1;
  $ipposition = $this->lastip;
  while($low <= $high){
  $t = floor(($low+$high)/2);
  if($ip < strrev($this->getbyte(4,$this->firstip+$t7))){
  $high = $t - 1;
  } else {
  if($ip > strrev($this->getbyte(4,$this->getlong(3)))){
  $low = $t + 1;
  }else{
  $ipposition = $this->firstip+$t7;
  break;
  }
  }
  }
  return $ipposition;
  }
  private function getarea(){
  $b = $this->getbyte(1);
  switch(ord($b)){
  case self::REDIRECT_MODE_0 :
  return "未知";
  break;
  case self::REDIRECT_MODE_1:
  case self::REDIRECT_MODE_2:
  return $this->getstring("",$this->getlong(3));
  break;
  default:
  return $this->getstring($b);
  break;
  }
  }
  public function getiplocation($ip){
  $ippos = $this->iplocaltion($ip);
  $this->ip_range_begin = long2ip($this->getlong(4,$ippos));
  $this->ip_range_end = long2ip($this->getlong(4,$this->getlong(3)));
  $b = $this->getbyte(1);
  switch (ord($b)){
  case self::REDIRECT_MODE_1:
  $b = $this->getbyte(1,$this->getlong(3));
  if(ord($b) == REDIRECT_MODE_2){
  $countryoffset = $this->getlong(3);
  $this->area = $this->getarea();
  $this->country = $this->getstring("",$countryoffset);
  }else{
  $this->country = $this->getstring($b);
  $this->area = $this->getarea();
  }
  break;

        case self::REDIRECT_MODE_2:  
                $countryoffset = $this->getlong(3);  
                $this->area = $this->getarea();  
                $this->country = $this->getstring("",$countryoffset);  
            break;  
  
        default:  
            $this->country = $this->getstring($b);  
            $this->area    = $this->getarea();  
            break;  
    }  

  }
  }
  / /
  echo microtime();
  echo "\n";
  $iploca = new IpLocation;
  //$iploca = new IpLocation('QQWry.dat');
  echo $iploca->get('wrydat_version');
  echo "\n";
  echo $iploca->get('ipnumber');
  echo "\n";
  $iploca->getiplocation('211.44.32.34');
  /**/
  echo $iploca->get('ip_range_begin');
  echo "\n";
  echo $iploca->get('ip_range_end');
  echo "\n";
  echo $iploca->get('country');
  echo "\n";
  echo $iploca->get('area');

echo "\n";
echo $iploca->get('lastip');
echo "\n";
echo microtime();
echo "\n";
unset($iploca);