<?php

/*

 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between

 * Copyright (C) 2006-2009 Dan Fuhry

 * class_http.php - Pure PHP HTTP client library

 *

 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied

 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.

 */

//

// HTTP status codes

//

// Informational

define('HTTP_CONTINUE', 100);

define('HTTP_SWITCHING_PROTOCOLS', 101);

define('HTTP_PROCESSING', 102);

// Success

define('HTTP_OK', 200);

define('HTTP_CREATED', 201);

define('HTTP_ACCEPTED', 202);

define('HTTP_NON_AUTHORITATIVE', 203);

define('HTTP_NO_CONTENT', 204);

define('HTTP_RESET_CONTENT', 205);

define('HTTP_PARTIAL_CONTENT', 206);

define('HTTP_MULTI_STATUS', 207);

// Redirection

define('HTTP_MULTIPLE_CHOICES', 300);

define('HTTP_MOVED_PERMANENTLY', 301);

define('HTTP_FOUND', 302);

define('HTTP_SEE_OTHER', 303);

define('HTTP_NOT_MODIFIED', 304);

define('HTTP_USE_PROXY', 305);

define('HTTP_SWITCH_PROXY', 306);

define('HTTP_TEMPORARY_REDIRECT', 307);

// Client Error

define('HTTP_BAD_REQUEST', 400);

define('HTTP_UNAUTHORIZED', 401);

define('HTTP_PAYMENT_REQUIRED', 402);

define('HTTP_FORBIDDEN', 403);

define('HTTP_NOT_FOUND', 404);

define('HTTP_METHOD_NOT_ALLOWED', 405);

define('HTTP_NOT_ACCEPTABLE', 406);

define('HTTP_PROXY_AUTHENTICATION_REQUIRED', 407);

define('HTTP_REQUEST_TIMEOUT', 408);

define('HTTP_CONFLICT', 409);

define('HTTP_GONE', 410);

define('HTTP_LENGTH_REQUIRED', 411);

define('HTTP_PRECONDITION_FAILED', 412);

define('HTTP_REQUEST_ENTITY_TOO_LARGE', 413);

define('HTTP_REQUEST_URI_TOO_LONG', 414);

define('HTTP_UNSUPPORTED_MEDIA_TYPE', 415);

define('HTTP_REQUESTED_RANGE_NOT_SATISFIABLE', 416);

define('HTTP_EXPECTATION_FAILED', 417);

define('HTTP_UNPROCESSABLE_ENTITY', 422);

define('HTTP_LOCKED', 423);

define('HTTP_FAILED_DEPENDENCY', 424);

define('HTTP_UNORDERED_COLLECTION', 425);

define('HTTP_UPGRADE_REQUIRED', 426);

define('HTTP_RETRY_WITH', 449);

// Server error

define('HTTP_INTERNAL_SERVER_ERROR', 500);

define('HTTP_NOT_IMPLEMENTED', 501);

define('HTTP_BAD_GATEWAY', 502);

define('HTTP_SERVICE_TEMPORARILY_UNAVAILABLE', 503);

define('HTTP_GATEWAY_TIMEOUT', 504);

define('HTTP_HTTP_VERSION_NOT_SUPPORTED', 505);

define('HTTP_VARIANT_ALSO_NEGOTIATES', 506);

define('HTTP_INSUFFICIENT_STORAGE', 507);

define('HTTP_BANDWIDTH_LIMIT_EXCEEDED', 509);

define('HTTP_NOT_EXTENDED', 510);

/**

 * Class for making HTTP requests. This can do GET and POST, and when used properly it consumes under a meg of memory, even with huge files.

 * @package Enano

 * @subpackage Backend functions

 * @copyright 2007 Dan Fuhry

 */

class Request_HTTP

{

  /**

   * Switch to enable or disable debugging. You want this off on production sites.

   * @var bool

   */

  var $debug = false;

  /**

   * The host the request will be sent to.

   * @var string

   */

  var $host = '';

  /**

   * The TCP port our connection is (will be) on.

   * @var int

   */

  var $port = 80;

  /**

   * The request method. Can be GET or POST, defaults to GET.

   * @var string

   */

  var $method = 'GET';

  /**

   * The URI to the remote script.

   * @var string

   */

  var $uri = '';

  /**

   * The parameters to be sent on GET.

   * @var array (associative)

   */

  var $parms_get = array();

  /**

   * The parameters to be sent on POST. Ignored if $this->method == GET.

   * @var array (associative)

   */

  var $parms_post = array();

  /**

   * The list of cookies that will be sent.

   * @var array (associative)

   */

  var $cookies_out = array();

  /**

   * Additional request headers.

   * @var array (associative)

   */

  var $headers = array();

  /**

   * Cached response.

   * @var string, or bool:false if the request hasn't been sent yet

   */

  var $response = false;

  /**

   * Cached response code

   * @var int set to -1 if request hasn't been sent yet

   */

  var $response_code = -1;

  /**

   * Cached response code string

   * @var string or bool:false if the request hasn't been sent yet

   */

  var $response_string = false;

  /**

   * Resource for the socket. False if a connection currently isn't going.

   * @var resource

   */

  var $socket = false;

  /**

   * The state of our request. 0 means it hasn't been made yet. 1 means the socket is open, 2 means the socket is open and the request has been written, 3 means the headers have been fetched, and 4 means the request is completed.

   * @var int

   */

  var $state = 0;

  /**

   * Constructor.

   * @param string Hostname to send to

   * @param string URI (/index.php)

   * @param string Request method - GET or POST.

   * @param int Optional. The port to open the request on. Defaults to 80.

   */

  function Request_HTTP($host, $uri, $method = 'GET', $port = 80)

  {

    if ( !preg_match('/^(?:(([a-z0-9-]+\.)*?)([a-z0-9-]+)|\[[a-f0-9:]+\])$/', $host) )

      throw new Exception(__CLASS__ . ': Invalid hostname');

    // Yes - this really does support IPv6 URLs!

    $this->host = $host;

    $this->uri = $uri;

    if ( is_int($port) && $port >= 1 && $port <= 65535 )

      $this->port = $port;

    else

      throw new Exception(__CLASS__ . ': Invalid port');

    $method = strtoupper($method);

    if ( $method == 'GET' || $method == 'POST' )

      $this->method = $method;

    else

      throw new Exception(__CLASS__ . ': Invalid request method');

    $newline = "\r\n";

    $php_ver = PHP_VERSION;

    $server = ( isset($_SERVER['SERVER_SOFTWARE']) ) ? "Server: {$_SERVER['SERVER_SOFTWARE']}" : "CLI";

    $this->add_header('User-Agent', "PHP/$php_ver ({$server}; automated bot request)");

  }

  /**

   * Sets one or more cookies to be sent to the server.

   * @param string or array If a string, the cookie name. If an array, associative array in the form of cookiename => cookievalue

   * @param string or bool If a string, the cookie value. If boolean, defaults to false, param 1 should be an array, and this should not be passed.

   */

  function add_cookie($cookiename, $cookievalue = false)

  {

    if ( is_array($cookiename) && !$cookievalue )

    {

      foreach ( $cookiename as $name => $value )

      {

        $this->cookies_out[$name] = $value;

      }

    }

    else if ( is_string($cookiename) && is_string($cookievalue) )

    {

      $this->cookies_out[$cookiename] = $cookievalue;

    }

    else

    {

      throw new Exception(__METHOD__ . ': Invalid argument(s)');

    }

  }

  /**

   * Sets one or more request header values.

   * @param string or array If a string, the header name. If an array, associative array in the form of headername => headervalue

   * @param string or bool If a string, the header value. If boolean, defaults to false, param 1 should be an array, and this should not be passed.

   */

  function add_header($headername, $headervalue = false)

  {

    if ( is_array($headername) && !$headervalue )

    {

      foreach ( $headername as $name => $value )

      {

        $this->headers[$name] = $value;

      }

    }

    else if ( is_string($headername) && is_string($headervalue) )

    {

      $this->headers[$headername] = $headervalue;

    }

    else

    {

      throw new Exception(__METHOD__ . ': Invalid argument(s)');

    }

  }

  /**

   * Adds one or more values to be passed on GET.

   * @param string or array If a string, the parameter name. If an array, associative array in the form of parametername => parametervalue

   * @param string or bool If a string, the parameter value. If boolean, defaults to false, param 1 should be an array, and this should not be passed.

   */

  function add_get($getname, $getvalue = false)

  {

    if ( is_array($getname) && !$getvalue )

    {

      foreach ( $getname as $name => $value )

      {

        $this->parms_get[$name] = $value;

      }

    }

    else if ( is_string($getname) && is_string($getvalue) )

    {

      $this->parms_get[$getname] = $getvalue;

    }

    else

    {

      throw new Exception(__METHOD__ . ': Invalid argument(s)');

    }

  }

  /**

   * Adds one or more values to be passed on POST.

   * @param string or array If a string, the header name. If an array, associative array in the form of headername => headervalue

   * @param string or bool If a string, the header value. If boolean, defaults to false, param 1 should be an array, and this should not be passed.

   */

  function add_post($postname, $postvalue = false)

  {

    if ( is_array($postname) && !$postvalue )

    {

      foreach ( $postname as $name => $value )

      {

        $this->parms_post[$name] = $value;

      }

    }

    else if ( is_string($postname) && is_string($postvalue) )

    {

      $this->parms_post[$postname] = $postvalue;

    }

    else

    {

      throw new Exception(__METHOD__ . ': Invalid argument(s)');

    }

  }

  /**

   * Internal function to open up the socket.

   * @access private

   */

  function _sock_open(&$connection)

  {

    // Open connection

    $connection = fsockopen($this->host, $this->port, $errno, $errstr);

    if ( !$connection )

      throw new Exception(__METHOD__ . ": Could not make connection"); // to {$this->host}:{$this->port}: error $errno: $errstr");

    // 1 = socket open

    $this->state = 1;

  }

  /**

   * Internal function to actually write the request into the socket.

   * @access private

   */

  function _write_request(&$connection, &$headers, &$cookies, &$get, &$post)

  {

    $newline = "\r\n";

    if ( $this->debug )

      echo '<p>Connection opened. Writing main request to socket. Raw socket data follows.</p><pre>';

    if ( $this->debug )

    {

      echo '<hr /><div style="white-space: nowrap;">';

      echo '<p><b>' . __CLASS__ . ': Sending request</b></p><p>Request parameters:</p>';

      echo "<p><b>Headers:</b></p><pre>$headers</pre>";

      echo "<p><b>Cookies:</b> $cookies</p>";

      echo "<p><b>GET URI:</b> " . htmlspecialchars($this->uri . $get) . "</p>";

      echo "<p><b>POST DATA:</b> " . htmlspecialchars($post) . "</p>";

      echo "<pre>";

    }

    $portline = ( $this->port == 80 ) ? '' : ":$this->port";

    $this->_fputs($connection, "{$this->method} {$this->uri}{$get} HTTP/1.1{$newline}");

    $this->_fputs($connection, "Host: {$this->host}$portline{$newline}");

    $this->_fputs($connection, $headers);

    $this->_fputs($connection, $cookies);

    if ( $this->method == 'POST' )

    {

      // POST-specific parameters

      $post_length = strlen($post);

      $this->_fputs($connection, "Content-type: application/x-www-form-urlencoded{$newline}");

      $this->_fputs($connection, "Content-length: {$post_length}{$newline}");

    }

    $this->_fputs($connection, "Connection: close{$newline}");

    $this->_fputs($connection, "{$newline}");

    if ( $this->method == 'POST' )

    {

      $this->_fputs($connection, $post);

    }

    if ( $this->debug )

      echo '</pre><p>Request written. Fetching response.</p>';

    // 2 = request written

    $this->state = 2;

  }

  /**

   * Wrap up and close the socket. Nothing more than a call to fsockclose() except in debug mode.

   * @access private

   */

  function sock_close(&$connection)

  {

    if ( $this->debug )

    {

      echo '<p>Response fetched. Closing connection. Response text follows.</p><pre>';

      echo htmlspecialchars($this->response);

      echo '</pre></div><hr />';

    }

    fclose($connection);

  }

  /**

   * Internal function to grab the response code and status string

   * @access string

   */

  function _parse_response_code($buffer)

  {

    // Retrieve response code and status

    $pos_newline = strpos($buffer, "\n");

    $pos_carriage_return = strpos($buffer, "\r");

    $pos_end_first_line = ( $pos_carriage_return < $pos_newline && $pos_carriage_return > 0 ) ? $pos_carriage_return : $pos_newline;

    // First line is in format of:

    // HTTP/1.1 ### Blah blah blah(\r?)\n

    $response_code = substr($buffer, 9, 3);

    $response_string = substr($buffer, 13, ( $pos_end_first_line - 13 ) );

    $this->response_code = intval($response_code);

    $this->response_string = $response_string;

  }

  /**

   * Internal function to send the request.

   * @access private

   */

  function _send_request()

  {

    $this->concat_headers($headers, $cookies, $get, $post);

    if ( $this->state < 1 )

    {

      $this->_sock_open($this->socket);

    }

    if ( $this->state < 2 )

    {

      $this->_write_request($this->socket, $headers, $cookies, $get, $post);

    }

    if ( $this->state == 2 )

    {

      $buffer = $this->_read_until_newlines($this->socket);

      $this->state = 3;

      $this->_parse_response_code($buffer);

      $this->response = $buffer;

    }

    if ( $this->state == 3 )

    {

      // Determine transfer encoding

      $is_chunked = preg_match("/Transfer-Encoding: (chunked)\r?\n/", $this->response);

      $buffer = '';

      while ( !feof($this->socket) )

      {

        $part = fgets($this->socket, 1024);

        if ( $is_chunked && preg_match("/^([a-f0-9]+)\x0D\x0A$/", $part, $match) )

        {

          $chunklen = hexdec($match[1]);

          $part = ( $chunklen > 0 ) ? fread($this->socket, $chunklen) : '';

          // remove the last newline from $part

          $part = preg_replace("/\r?\n\$/m", "", $part);

        }

        $buffer .= $part;

      }

      $this->response .= $buffer;

    }

    $this->state = 4;

    $this->sock_close($this->socket);

    $this->socket = false;

  }

  /**

   * Internal function to send the request but only fetch the headers. Leaves a connection open for a finish-up function.

   * @access private

   */

  function _send_request_headers_only()

  {

    $this->concat_headers($headers, $cookies, $get, $post);

    if ( $this->state < 1 )

    {

      $this->_sock_open($this->socket);

    }

    if ( $this->state < 2 )

    {

      $this->_write_request($this->socket, $headers, $cookies, $get, $post);

    }

    if ( $this->state == 2 )

    {

      $buffer = $this->_read_until_newlines($this->socket);

      $this->state = 3;

      $this->_parse_response_code($buffer);

      $this->response = $buffer;

    }

  }

  /**

   * Internal function to read from a socket until two consecutive newlines are hit.

   * @access private

   */

  function _read_until_newlines($sock)

  {

    $prev_char = '';

    $prev1_char = '';

    $prev2_char = '';

    $buf = '';

    while ( !feof($sock) )

    {

      $chr = fread($sock, 1);

      $buf .= $chr;

      if ( ( $chr == "\n" && $prev_char == "\n" ) ||

           ( $chr == "\n" && $prev_char == "\r" && $prev1_char == "\n" && $prev2_char == "\r" ) )

      {

        return $buf;

      }

      $prev2_char = $prev1_char;

      $prev1_char = $prev_char;