File: //opt/cloudlinux/alt-php54/root/usr/share/pear/Net/DNS2/Packet.php
<?php
/**
* DNS Library for handling lookups and updates.
*
* Copyright (c) 2020, Mike Pultz <mike@mikepultz.com>. All rights reserved.
*
* See LICENSE for more details.
*
* @category Networking
* @package Net_DNS2
* @author Mike Pultz <mike@mikepultz.com>
* @copyright 2020 Mike Pultz <mike@mikepultz.com>
* @license http://www.opensource.org/licenses/bsd-license.php BSD License
* @link https://netdns2.com/
* @since File available since Release 0.6.0
*
* This file contains code based off the Net::DNS Perl module by Michael Fuhr.
*
* This is the copyright notice from the PERL Net::DNS module:
*
* Copyright (c) 1997-2000 Michael Fuhr. All rights reserved. This program is
* free software; you can redistribute it and/or modify it under the same terms
* as Perl itself.
*
*/
/**
* This is the base class that holds a standard DNS packet.
*
* The Net_DNS2_Packet_Request and Net_DNS2_Packet_Response classes extend this
* class.
*
*/
class Net_DNS2_Packet
{
/*
* the full binary data and length for this packet
*/
public $rdata;
public $rdlength;
/*
* the offset pointer used when building/parsing packets
*/
public $offset = 0;
/*
* Net_DNS2_Header object with the DNS packet header
*/
public $header;
/*
* array of Net_DNS2_Question objects
*
* used as "zone" for updates per RFC2136
*
*/
public $question = [];
/*
* array of Net_DNS2_RR Objects for Answers
*
* used as "prerequisite" for updates per RFC2136
*
*/
public $answer = [];
/*
* array of Net_DNS2_RR Objects for Authority
*
* used as "update" for updates per RFC2136
*
*/
public $authority = [];
/*
* array of Net_DNS2_RR Objects for Addtitional
*/
public $additional = [];
/*
* array of compressed labeles
*/
private $_compressed = [];
/**
* magic __toString() method to return the Net_DNS2_Packet as a string
*
* @return string
* @access public
*
*/
public function __toString()
{
$output = $this->header->__toString();
foreach ($this->question as $x) {
$output .= $x->__toString() . "\n";
}
foreach ($this->answer as $x) {
$output .= $x->__toString() . "\n";
}
foreach ($this->authority as $x) {
$output .= $x->__toString() . "\n";
}
foreach ($this->additional as $x) {
$output .= $x->__toString() . "\n";
}
return $output;
}
/**
* returns a full binary DNS packet
*
* @return string
* @throws Net_DNS2_Exception
* @access public
*
*/
public function get()
{
$data = $this->header->get($this);
foreach ($this->question as $x) {
$data .= $x->get($this);
}
foreach ($this->answer as $x) {
$data .= $x->get($this);
}
foreach ($this->authority as $x) {
$data .= $x->get($this);
}
foreach ($this->additional as $x) {
$data .= $x->get($this);
}
return $data;
}
/**
* applies a standard DNS name compression on the given name/offset
*
* This logic was based on the Net::DNS::Packet::dn_comp() function
* by Michanel Fuhr
*
* @param string $name the name to be compressed
* @param integer &$offset the offset into the given packet object
*
* @return string
* @access public
*
*/
public function compress($name, &$offset)
{
//
// we're using preg_split() rather than explode() so that we can use the negative lookbehind,
// to catch cases where we have escaped dots in strings.
//
// there's only a few cases like this- the rname in SOA for example
//
$names = str_replace('\.', '.', preg_split('/(?<!\\\)\./', $name));
$compname = '';
while (!empty($names)) {
$dname = join('.', $names);
if (isset($this->_compressed[$dname])) {
$compname .= pack('n', 0xc000 | $this->_compressed[$dname]);
$offset += 2;
break;
}
$this->_compressed[$dname] = $offset;
$first = array_shift($names);
$length = strlen($first);
if ($length <= 0) {
continue;
}
//
// truncate see RFC1035 2.3.1
//
if ($length > 63) {
$length = 63;
$first = substr($first, 0, $length);
}
$compname .= pack('Ca*', $length, $first);
$offset += $length + 1;
}
if (empty($names)) {
$compname .= pack('C', 0);
$offset++;
}
return $compname;
}
/**
* applies a standard DNS name compression on the given name/offset
*
* This logic was based on the Net::DNS::Packet::dn_comp() function
* by Michanel Fuhr
*
* @param string $name the name to be compressed
*
* @return string
* @access public
*
*/
public static function pack($name)
{
$offset = 0;
$names = explode('.', $name);
$compname = '';
while (!empty($names)) {
$first = array_shift($names);
$length = strlen($first);
$compname .= pack('Ca*', $length, $first);
$offset += $length + 1;
}
$compname .= "\0";
$offset++;
return $compname;
}
/**
* expands the domain name stored at a given offset in a DNS Packet
*
* This logic was based on the Net::DNS::Packet::dn_expand() function
* by Michanel Fuhr
*
* @param Net_DNS2_Packet &$packet the DNS packet to look in for the domain name
* @param integer &$offset the offset into the given packet object
* @param boolean $escape_dot_literals if we should escape periods in names
*
* @return mixed either the domain name or null if it's not found.
* @access public
*
*/
public static function expand(Net_DNS2_Packet &$packet, &$offset, $escape_dot_literals = false)
{
$name = '';
while (1) {
if ($packet->rdlength < ($offset + 1)) {
return null;
}
$xlen = ord($packet->rdata[$offset]);
if ($xlen == 0) {
++$offset;
break;
} else if (($xlen & 0xc0) == 0xc0) {
if ($packet->rdlength < ($offset + 2)) {
return null;
}
$ptr = ord($packet->rdata[$offset]) << 8 | ord($packet->rdata[$offset+1]);
$ptr = $ptr & 0x3fff;
$name2 = Net_DNS2_Packet::expand($packet, $ptr);
if (is_null($name2)) {
return null;
}
$name .= $name2;
$offset += 2;
break;
} else {
++$offset;
if ($packet->rdlength < ($offset + $xlen)) {
return null;
}
$elem = '';
$elem = substr($packet->rdata, $offset, $xlen);
//
// escape literal dots in certain cases (SOA rname)
//
if ( ($escape_dot_literals == true) && (strpos($elem, '.') !== false) ) {
$elem = str_replace('.', '\.', $elem);
}
$name .= $elem . '.';
$offset += $xlen;
}
}
return trim($name, '.');
}
/**
* parses a domain label from a DNS Packet at the given offset
*
* @param Net_DNS2_Packet &$packet the DNS packet to look in for the domain name
* @param integer &$offset the offset into the given packet object
*
* @return mixed either the domain name or null if it's not found.
* @access public
*
*/
public static function label(Net_DNS2_Packet &$packet, &$offset)
{
$name = '';
if ($packet->rdlength < ($offset + 1)) {
return null;
}
$xlen = ord($packet->rdata[$offset]);
++$offset;
if (($xlen + $offset) > $packet->rdlength) {
$name = substr($packet->rdata, $offset);
$offset = $packet->rdlength;
} else {
$name = substr($packet->rdata, $offset, $xlen);
$offset += $xlen;
}
return $name;
}
/**
* copies the contents of the given packet, to the local packet object. this
* function intentionally ignores some of the packet data.
*
* @param Net_DNS2_Packet $packet the DNS packet to copy the data from
*
* @return boolean
* @access public
*
*/
public function copy(Net_DNS2_Packet $packet)
{
$this->header = $packet->header;
$this->question = $packet->question;
$this->answer = $packet->answer;
$this->authority = $packet->authority;
$this->additional = $packet->additional;
return true;
}
/**
* resets the values in the current packet object
*
* @return boolean
* @access public
*
*/
public function reset()
{
$this->header->id = $this->header->nextPacketId();
$this->rdata = '';
$this->rdlength = 0;
$this->offset = 0;
$this->answer = [];
$this->authority = [];
$this->additional = [];
$this->_compressed = [];
return true;
}
}