75 lines
1.7 KiB
PHP
75 lines
1.7 KiB
PHP
<?php
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/**
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* DNS Library for handling lookups and updates.
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*
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* Copyright (c) 2022, Mike Pultz <mike@mikepultz.com>. All rights reserved.
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*
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* See LICENSE for more details.
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*
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* @category Networking
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* @package Net_DNS2
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* @author Mike Pultz <mike@mikepultz.com>
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* @copyright 2022 Mike Pultz <mike@mikepultz.com>
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* @license http://www.opensource.org/licenses/bsd-license.php BSD License
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* @link https://netdns2.com/
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* @since File available since Release 1.5.3
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*
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*/
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/**
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* text compression/expansion and labeling class
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*
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*/
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class Net_DNS2_Names
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{
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/**
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* pack a text string
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*
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* @param string $name a name to be packed
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*
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* @return string
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* @access public
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*
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*/
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public static function pack($name)
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{
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return (is_null($name) == true) ? null : pack('Ca*', strlen($name), $name);
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}
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/**
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* parses a domain string into a single string
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*
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* @param Net_DNS2_Packet &$packet the DNS packet to look in for the domain name
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* @param integer &$offset the offset into the given packet object
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*
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* @return mixed either a name string or null if it's not found.
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* @access public
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*
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*/
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public static function unpack($rdata, &$offset)
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{
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$name = '';
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if (strlen($rdata) < ($offset + 1))
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{
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return null;
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}
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$xlen = ord($rdata[$offset]);
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++$offset;
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if (($xlen + $offset) > strlen($rdata)) {
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$name = substr($rdata, $offset);
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$offset = strlen($rdata);
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} else {
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$name = substr($rdata, $offset, $xlen);
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$offset += $xlen;
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}
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return trim($name, '.');
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}
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}
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