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<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* DNS Library for handling lookups and updates.
*
* PHP Version 5
*
* Copyright (c) 2010, Mike Pultz <mike@mikepultz.com>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of Mike Pultz nor the names of his contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRIC
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* @category Networking
* @package Net_DNS2
* @author Mike Pultz <mike@mikepultz.com>
* @copyright 2010 Mike Pultz <mike@mikepultz.com>
* @license http://www.opensource.org/licenses/bsd-license.php BSD License
* @version SVN: $Id: Streams.php 107 2011-06-26 07:44:20Z mike.pultz $
* @link http://pear.php.net/package/Net_DNS2
* @since File available since Release 0.6.0
*
*/
/**
* Socket handling class using the PHP Streams
*
* The sockets extension is faster than the stream functions in PHP, but it's
* not standard. So if the extension is loaded, then the Net_DNS_Socket_Sockets
* class it used, otherwise, this class it used.
*
* @category Networking
* @package Net_DNS2
* @author Mike Pultz <mike@mikepultz.com>
* @license http://www.opensource.org/licenses/bsd-license.php BSD License
* @link http://pear.php.net/package/Net_DNS2
* @see Net_DNS2_Socket
*
*/
class Net_DNS2_Socket_Streams extends Net_DNS2_Socket
{
private $_context;
/**
* opens a socket connection to the DNS server
*
* @return boolean
* @access public
*
*/
public function open()
{
//
// create a list of options for the context
//
$opts = array('socket' => array());
//
// bind to a local IP/port if it's set
//
if (strlen($this->local_host) > 0) {
$opts['socket']['bindto'] = $this->local_host;
if ($this->local_port > 0) {
$opts['socket']['bindto'] .= ':' . $this->local_port;
}
}
//
// create the context
//
$this->_context = @stream_context_create($opts);
//
// create socket
//
$errno;
$errstr;
switch($this->type) {
case SOCK_STREAM:
if (Net_DNS2::isIPv4($this->host) == true) {
$this->_sock = @stream_socket_client(
'tcp://' . $this->host . ':' . $this->port,
$errno, $errstr, $this->timeout,
STREAM_CLIENT_CONNECT, $this->_context
);
} else if (Net_DNS2::isIPv6($this->host) == true) {
$this->_sock = @stream_socket_client(
'tcp://[' . $this->host . ']:' . $this->port,
$errno, $errstr, $this->timeout,
STREAM_CLIENT_CONNECT, $this->_context
);
} else {
$this->last_error = 'invalid address type: ' . $this->host;
return false;
}
break;
case SOCK_DGRAM:
if (Net_DNS2::isIPv4($this->host) == true) {
$this->_sock = @stream_socket_client(
'udp://' . $this->host . ':' . $this->port,
$errno, $errstr, $this->timeout,
STREAM_CLIENT_CONNECT, $this->_context
);
} else if (Net_DNS2::isIPv6($this->host) == true) {
$this->_sock = @stream_socket_client(
'udp://[' . $this->host . ']:' . $this->port,
$errno, $errstr, $this->timeout,
STREAM_CLIENT_CONNECT, $this->_context
);
} else {
$this->last_error = 'invalid address type: ' . $this->host;
return false;
}
break;
default:
$this->last_error = 'Invalid socket type: ' . $this->type;
return false;
}
if ($this->_sock === false) {
$this->last_error = $errstr;
return false;
}
//
// set it to non-blocking and set the timeout
//
@stream_set_blocking($this->_sock, 0);
@stream_set_timeout($this->_sock, $this->timeout);
return true;
}
/**
* closes a socket connection to the DNS server
*
* @return boolean
* @access public
*
*/
public function close()
{
if (is_resource($this->_sock) === true) {
@fclose($this->_sock);
}
return true;
}
/**
* writes the given string to the DNS server socket
*
* @param string $data a binary packed DNS packet
*
* @return boolean
* @access public
*
*/
public function write($data)
{
$length = strlen($data);
if ($length == 0) {
$this->last_error = 'empty data on write()';
return false;
}
$read = null;
$write = array($this->_sock);
$except = null;
//
// select on write
//
switch(@stream_select($read, $write, $except, $this->timeout)) {
case false:
$this->last_error = 'failed on stream_select()';
return false;
break;
case 0:
return false;
break;
default:
;
}
//
// if it's a TCP socket, then we need to packet and send the length of the
// data as the first 16bit of data.
//
if ($this->type == SOCK_STREAM) {
$s = chr($length >> 8) . chr($length);
if (@fwrite($this->_sock, $s) === false) {
$this->last_error = 'failed to fwrite() 16bit length';
return false;
}
}
//
// write the data to the socket
//
$size = @fwrite($this->_sock, $data);
if ( ($size === false) || ($size != $length) ) {
$this->last_error = 'failed to fwrite() packet';
return false;
}
return true;
}
/**
* reads a response from a DNS server
*
* @param integer &$size the size of the DNS packet read is passed back
*
* @return mixed returns the data on success and false on error
* @access public
*
*/
public function read(&$size)
{
$read = array($this->_sock);
$write = null;
$except = null;
//
// select on read
//
switch(stream_select($read, $write, $except, $this->timeout)) {
case false:
$this->last_error = 'error on stream_select()';
return false;
break;
case 0:
return false;
break;
default:
;
}
$data = '';
$length = Net_DNS2_Lookups::DNS_MAX_UDP_SIZE;
//
// if it's a TCP socket, then the first two bytes is the length of the DNS
// packet- we need to read that off first, then use that value for the
// packet read.
//
if ($this->type == SOCK_STREAM) {
if (($data = fread($this->_sock, 2)) === false) {
$this->last_error = 'failed on fread() for data length';
return false;
}
$length = ord($data[0]) << 8 | ord($data[1]);
if ($length < Net_DNS2_Lookups::DNS_HEADER_SIZE) {
return false;
}
}
//
// read the data from the socket
//
if (($data = fread($this->_sock, $length)) === false) {
$this->last_error = 'failed on fread() for data';
return false;
}
$size = strlen($data);
return $data;
}
}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* c-hanging-comment-ender-p: nil
* End:
*/
?>
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