Discuz 5.0 Read the pure IP database function Analysis _php tutorial

Discuz 5.0 is not using their own IP data, but the use of pure IP data format, access to the pure IP database a little bit of trouble, its storage format is very special and interesting, specific format analysis refer to the following two links, other languages to implement the link at the end of the reference article.

"Pure IP database format detailed"
Link One: http://blog.csdn.net/heiyeshuwu/archive/2006/05/12/725675.aspx
Link two: http://lumaqq.linuxsir.org/article/qqwry_format_detail.html

Pure IP Database official website: http://www.cz88.net/ip/
Pure IP Database Download: Http://update.cz88.net/soft/qqwry.rar


The following function Conrvertip () is located in the discuz!5_gbk/upload/include/misc.func.php path and is interested in reading the analysis in detail. (The following code I made a simple modification, more convenient to read, the core is not modified)


//===================================
//
Function: IP address get real address function
Parameter: $ip-IP address
Author: [discuz!] (C) Comsenz Inc.
//
//===================================
function Convertip ($IP) {
IP Data File path
$dat _path = ' QQWry.Dat ';

Check IP Address
if (!preg_match ("/^d{1,3}.d{1,3}.d{1,3}.d{1,3}$/", $ip)) {
Return ' IP address Error ';
}
Open IP Data file
if (! $fd = @fopen ($dat _path, ' RB ')) {
Return ' IP date file not exists or access denied ';
}

Decomposition IP for operation, resulting in shaping number
$ip = Explode ('. ', $IP);
$ipNum = $ip [0] * 16777216 + $ip [1] * 65536 + $ip [2] * + + $ip [3];

Get IP Data index start and end locations
$DataBegin = Fread ($FD, 4);
$DataEnd = Fread ($FD, 4);
$ipbegin = Implode (' ', Unpack (' L ', $DataBegin));
if ($ipbegin < 0) $ipbegin + = POW (2, 32);
$ipend = Implode (' ', Unpack (' L ', $DataEnd));
if ($ipend < 0) $ipend + = POW (2, 32);
$ipAllNum = ($ipend-$ipbegin)/7 + 1;

$BeginNum = 0;
$EndNum = $ipAllNum;

Search for matching IP records from index records using the binary lookup method
while ($ip 1num> $ipNum | | $ip 2num< $ipNum) {
$Middle = Intval (($EndNum + $BeginNum)/2);

Offset pointer to index position read 4 bytes
Fseek ($FD, $ipbegin + 7 * $Middle);
$ipData 1 = fread ($FD, 4);
if (strlen ($ipData 1) < 4) {
Fclose ($FD);
Return ' System Error ';
}
Extracted data transformation growth shaping, if the data is negative, plus 2 of the power of 32
$ip 1num = Implode (', Unpack (' L ', $ipData 1));
if ($ip 1num < 0) $ip 1num + = POW (2, 32);

Extract the number of long integers greater than our IP address then modify the end position for the next loop
if ($ip 1num > $ipNum) {
$EndNum = $Middle;
Continue
}

Remove an index after the last index is taken
$DataSeek = Fread ($FD, 3);
if (strlen ($DataSeek) < 3) {
Fclose ($FD);
Return ' System Error ';
}
$DataSeek = Implode (', Unpack (' L ', $DataSeek. chr (0)));
Fseek ($FD, $DataSeek);
$ipData 2 = fread ($FD, 4);
if (strlen ($ipData 2) < 4) {
Fclose ($FD);
Return ' System Error ';
}
$ip 2num = Implode (', Unpack (' L ', $ipData 2));
if ($ip 2num < 0) $ip 2num + = POW (2, 32);

No hints found
if ($ip 2num < $ipNum) {
if ($Middle = = $BeginNum) {
Fclose ($FD);
Return ' Unknown ';
}
$BeginNum = $Middle;
}
}

The following code read dizzy, did not read clearly, interested in reading slowly
$ipFlag = Fread ($FD, 1);
if ($ipFlag = = Chr (1)) {
$ipSeek = Fread ($FD, 3);
if (strlen ($ipSeek) < 3) {
Fclose ($FD);
Return ' System Error ';
}
$ipSeek = Implode (', Unpack (' L ', $ipSeek. chr (0)));
Fseek ($FD, $ipSeek);
$ipFlag = Fread ($FD, 1);
}

if ($ipFlag = = Chr (2)) {
$AddrSeek = Fread ($FD, 3);
if (strlen ($AddrSeek) < 3) {
Fclose ($FD);
Return ' System Error ';
}
$ipFlag = Fread ($FD, 1);
if ($ipFlag = = Chr (2)) {
$AddrSeek 2 = fread ($FD, 3);
if (strlen ($AddrSeek 2) < 3) {
Fclose ($FD);
Return ' System Error ';
}
$AddrSeek 2 = Implode ("', Unpack (' L ', $AddrSeek 2.chr (0)));
Fseek ($FD, $AddrSeek 2);
} else {
Fseek ($FD,-1, seek_cur);
}

while ($char = Fread ($FD, 1))! = Chr (0))
$ipAddr 2. = $char;

$AddrSeek = Implode (', Unpack (' L ', $AddrSeek. chr (0)));
Fseek ($FD, $AddrSeek);

while ($char = Fread ($FD, 1))! = Chr (0))
$ipAddr 1. = $char;
} else {
Fseek ($FD,-1, seek_cur);
while ($char = Fread ($FD, 1))! = Chr (0))
$ipAddr 1. = $char;

$ipFlag = Fread ($FD, 1);
if ($ipFlag = = Chr (2)) {
$AddrSeek 2 = fread ($FD, 3);
if (strlen ($AddrSeek 2) < 3) {
Fclose ($FD);
Return ' System Error ';
}
$AddrSeek 2 = Implode ("', Unpack (' L ', $AddrSeek 2.chr (0)));
Fseek ($FD, $AddrSeek 2);
} else {
Fseek ($FD,-1, seek_cur);
}
while ($char = Fread ($FD, 1))! = Chr (0)) {
$ipAddr 2. = $char;
}
}
Fclose ($FD);

The result is returned after the corresponding substitution operation is finally made
if (Preg_match ('/http/i ', $ipAddr 2)) {
$ipAddr 2 = ";
}
$IPADDR = "$ipAddr 1 $ipAddr 2";
$IPADDR = preg_replace ('/cz88.net/is ', ' ', $ipaddr);
$IPADDR = preg_replace ('/^s*/is ', ' ', $ipaddr);
$IPADDR = preg_replace ('/s*$/is ', ' ', $ipaddr);
if (Preg_match ('/http/i ', $ipaddr) | | $ipaddr = = ") {
$ipaddr = ' Unknown ';
}

return $ipaddr;
}


//========================
//
invocation example (FAST)
//
//========================

echo convertip (' 219.238.235.10 ');
Output: Beijing Telecom Pass

echo convertip (' 23.56.82.12 ');
Output: IANA

echo convertip (' 250.69.52.0 ');
Output: IANA reserved address

echo convertip (' 238.69.52.0 ');
Output: IANA reserved addresses for multicast

echo convertip (' 192.168.0.1 ');
Output: LAN each other and you on the same intranet

echo convertip (' 255.255.255.255 ');
Output: Pure network November 20, 2006 IP data

?>

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