<?php
/////////////////////////////////////////////////
// PukiWiki - Yet another WikiWikiWeb clone.
//
// $Id: proxy.php,v 1.2 2004/10/13 14:30:58 henoheno Exp $
//

/*
 * http_request($url)
 *   HTTPリクエストを発行し、データを取得する
 * $url     : http://から始まるURL(http://user:pass@host:port/path?query)
 * $method  : GET, POST, HEADのいずれか(デフォルトはGET)
 * $headers : 任意の追加ヘッダ
 * $post    : POSTの時に送信するデータを格納した配列('変数名'=>'値')
 * $redirect_max : HTTP redirectの回数制限
*/

// リダイレクト回数制限の初期値
define('HTTP_REQUEST_URL_REDIRECT_MAX', 10);

function http_request($url, $method = 'GET', $headers = '', $post = array(),
	$redirect_max = HTTP_REQUEST_URL_REDIRECT_MAX)
{
	global $proxy_host, $proxy_port;
	global $need_proxy_auth, $proxy_auth_user, $proxy_auth_pass;

	$rc  = array();
	$arr = parse_url($url);

	$via_proxy = via_proxy($arr['host']);

	// query
	$arr['query'] = isset($arr['query']) ? '?' . $arr['query'] : '';
	// port
	$arr['port']  = isset($arr['port'])  ? $arr['port'] : 80;

	$url_base = $arr['scheme'] . '://' . $arr['host'] . ':' . $arr['port'];
	$url_path = isset($arr['path']) ? $arr['path'] : '/';
	$url = ($via_proxy ? $url_base : '') . $url_path . $arr['query'];

	$query = $method . ' ' . $url . " HTTP/1.0\r\n";
	$query .= 'Host: ' . $arr['host'] . "\r\n";
	$query .= 'User-Agent: PukiWiki/' . S_VERSION . "\r\n";

	// proxyのBasic認証
	if ($need_proxy_auth && isset($proxy_auth_user) && isset($proxy_auth_pass)) {
		$query .= 'Proxy-Authorization: Basic '.
			base64_encode($proxy_auth_user . ':' . $proxy_auth_pass) . "\r\n";
	}

	// Basic 認証用
	if (isset($arr['user']) && isset($arr['pass'])) {
		$query .= 'Authorization: Basic '.
			base64_encode($arr['user'] . ':' . $arr['pass']) . "\r\n";
	}

	$query .= $headers;

	// POST 時は、urlencode したデータとする
	if (strtoupper($method) == 'POST') {
		$POST = array();
		foreach ($post as $name=>$val) {
			$POST[] = $name . '=' . urlencode($val);
		}
		$data = join('&', $POST);
		$query .= "Content-Type: application/x-www-form-urlencoded\r\n";
		$query .= 'Content-Length: ' . strlen($data) . "\r\n";
		$query .= "\r\n";
		$query .= $data;
	} else {
		$query .= "\r\n";
	}

	$errno = 0; $errstr = '';
	$fp = fsockopen(
		$via_proxy ? $proxy_host : $arr['host'],
		$via_proxy ? $proxy_port : $arr['port'],
		$errno, $errstr, 30);
	if ($fp === FALSE) {
		return array(
			'query'  => $query, // Query String
			'rc'     => $errno, // エラー番号
			'header' => '',     // Header
			'data'   => $errstr // エラーメッセージ
		);
	}

	fputs($fp, $query);

	$response = '';
	while (! feof($fp))
		$response .= fread($fp, 4096);
	fclose($fp);

	$resp = explode("\r\n\r\n", $response, 2);
	$rccd = explode(' ', $resp[0], 3); // array('HTTP/1.1', '200', 'OK\r\n...')
	$rc = (integer)$rccd[1];

	// Redirect
	$matches = array();
	switch ($rc) {
	case 302: // Moved Temporarily
	case 301: // Moved Permanently
		if (preg_match('/^Location: (.+)$/m', $resp[0], $matches)
			&& --$redirect_max > 0)
		{
			$url = trim($matches[1]);
			if (! preg_match('/^https?:\//', $url)) {
				// No scheme
				if ($url{0} != '/') {
					// Relative path to Absolute
					$url = substr($url_path, 0, strrpos($url_path, '/')) . '/' . $url;
				}
				$url = $url_base . $url; // Add sheme, host
			}
			return http_request($url, $method, $headers, $post, $redirect_max);
		}
	}

	return array(
		'query'  => $query,   // Query String
		'rc'     => $rc,      // Response Code
		'header' => $resp[0], // Header
		'data'   => $resp[1]  // Data
	);
}

// プロキシを経由する必要があるかどうか判定
function via_proxy($host)
{
	global $use_proxy, $no_proxy;
	static $ip_pattern = '/^(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})(?:\/(.+))?$/';

	if (! $use_proxy) return FALSE;

	$ip    = gethostbyname($host);
	$l_ip  = ip2long($ip);
	$valid = (is_long($l_ip) && long2ip($l_ip) == $ip); // valid ip address

	$matches = array();
	foreach ($no_proxy as $network) {
		if ($valid && preg_match($ip_pattern, $network, $matches)) {
			$l_net = ip2long($matches[1]);
			$mask  = isset($matches[2]) ? $matches[2] : 32;
			$mask  = is_numeric($mask) ?
				pow(2, 32) - pow(2, 32 - $mask) : // "10.0.0.0/8"
				ip2long($mask);                   // "10.0.0.0/255.0.0.0"

			if (($l_ip & $mask) == $l_net) return FALSE;
		} else {
			if (preg_match('/' . preg_quote($network, '/') . '/', $host))
				return FALSE;
		}
	}
	return TRUE;
}
?>