在 Windows 平台上执行 MX 查询的另一种方法。
我从之前为 DNS 查询编写的另一个类中改写了这段代码 - 所以可能有点混乱 - 但是希望你能明白我的意思。
非常感谢 RFC 社区。
<?php
class mxlookup
{
var $dns_socket = NULL;
var $QNAME = "";
var $dns_packet= NULL;
var $ANCOUNT = 0;
var $cIx = 0;
var $dns_repl_domain;
var $arrMX = array();
function mxlookup($domain, $dns="192.168.2.1")
{
$this->QNAME($domain);
$this->pack_dns_packet();
$dns_socket = fsockopen("udp://$dns", 53);
fwrite($dns_socket,$this->dns_packet,strlen($this->dns_packet));
$this->dns_reply = fread($dns_socket,1);
$bytes = stream_get_meta_data($dns_socket);
$this->dns_reply .= fread($dns_socket,$bytes['unread_bytes']);
fclose($dns_socket);
$this->cIx=6;
$this->ANCOUNT = $this->gord(2);
$this->cIx+=4;
$this->parse_data($this->dns_repl_domain);
$this->cIx+=7;
for($ic=1;$ic<=$this->ANCOUNT;$ic++)
{
$QTYPE = ord($this->gdi($this->cIx));
if($QTYPE!==15){print("[MX Record not returned]"); die();}
$this->cIx+=9;
$mxPref = ord($this->gdi($this->cIx));
$this->parse_data($curmx);
$this->arrMX[] = array("MX_Pref" => $mxPref, "MX" => $curmx);
$this->cIx+=3;
}
}
function parse_data(&$retval)
{
$arName = array();
$byte = ord($this->gdi($this->cIx));
while($byte!==0)
{
if($byte==192) {
$tmpIx = $this->cIx;
$this->cIx = ord($this->gdi($cIx));
$tmpName = $retval;
$this->parse_data($tmpName);
$retval=$retval.".".$tmpName;
$this->cIx = $tmpIx+1;
return;
}
$retval="";
$bCount = $byte;
for($b=0;$b<$bCount;$b++)
{
$retval .= $this->gdi($this->cIx);
}
$arName[]=$retval;
$byte = ord($this->gdi($this->cIx));
}
$retval=join(".",$arName);
}
function gdi(&$cIx,$bytes=1)
{
$this->cIx++;
return(substr($this->dns_reply, $this->cIx-1, $bytes));
}
function QNAME($domain)
{
$dot_pos = 0; $temp = "";
while($dot_pos=strpos($domain,"."))
{
$temp = substr($domain,0,$dot_pos);
$domain = substr($domain,$dot_pos+1);
$this->QNAME .= chr(strlen($temp)).$temp;
}
$this->QNAME .= chr(strlen($domain)).$domain.chr(0);
}
function gord($ln=1)
{
$reply="";
for($i=0;$i<$ln;$i++){
$reply.=ord(substr($this->dns_reply,$this->cIx,1));
$this->cIx++;
}
return $reply;
}
function pack_dns_packet()
{
$this->dns_packet = chr(0).chr(1).
chr(1).chr(0).
chr(0).chr(1).
chr(0).chr(0).
chr(0).chr(0).
chr(0).chr(0).
$this->QNAME.
chr(0).chr(15).
chr(0).chr(1);
}
}
?>
<?php
$mx = new mxlookup("php.net");
print $mx->ANCOUNT." MX 记录\n";
print "返回的 $mx->dns_repl_domain 的记录:\n<pre>";
print_r($mx->arrMX);
?>
返回
02 MX 记录 返回的 php.net 记录
数组
(
[0] => 数组
(
[MX_Pref] => 15
[MX] => smtp.osuosl.org
)
[1] => 数组
(
[MX_Pref] => 5
[MX] => osu1.php.net
)
)