1<?php
2/**
3 * PEAR_REST
4 *
5 * PHP versions 4 and 5
6 *
7 * @category   pear
8 * @package    PEAR
9 * @author     Greg Beaver <cellog@php.net>
10 * @copyright  1997-2009 The Authors
11 * @license    http://opensource.org/licenses/bsd-license.php New BSD License
12 * @link       http://pear.php.net/package/PEAR
13 * @since      File available since Release 1.4.0a1
14 */
15
16/**
17 * For downloading xml files
18 */
19require_once 'PEAR.php';
20require_once 'PEAR/XMLParser.php';
21require_once 'PEAR/Proxy.php';
22
23/**
24 * Intelligently retrieve data, following hyperlinks if necessary, and re-directing
25 * as well
26 * @category   pear
27 * @package    PEAR
28 * @author     Greg Beaver <cellog@php.net>
29 * @copyright  1997-2009 The Authors
30 * @license    http://opensource.org/licenses/bsd-license.php New BSD License
31 * @version    Release: @package_version@
32 * @link       http://pear.php.net/package/PEAR
33 * @since      Class available since Release 1.4.0a1
34 */
35class PEAR_REST
36{
37    var $config;
38    var $_options;
39
40    function __construct(&$config, $options = array())
41    {
42        $this->config   = &$config;
43        $this->_options = $options;
44    }
45
46    /**
47     * Retrieve REST data, but always retrieve the local cache if it is available.
48     *
49     * This is useful for elements that should never change, such as information on a particular
50     * release
51     * @param string full URL to this resource
52     * @param array|false contents of the accept-encoding header
53     * @param boolean     if true, xml will be returned as a string, otherwise, xml will be
54     *                    parsed using PEAR_XMLParser
55     * @return string|array
56     */
57    function retrieveCacheFirst($url, $accept = false, $forcestring = false, $channel = false)
58    {
59        $cachefile = $this->config->get('cache_dir') . DIRECTORY_SEPARATOR .
60            md5($url) . 'rest.cachefile';
61
62        if (file_exists($cachefile)) {
63            return unserialize(implode('', file($cachefile)));
64        }
65
66        return $this->retrieveData($url, $accept, $forcestring, $channel);
67    }
68
69    /**
70     * Retrieve a remote REST resource
71     * @param string full URL to this resource
72     * @param array|false contents of the accept-encoding header
73     * @param boolean     if true, xml will be returned as a string, otherwise, xml will be
74     *                    parsed using PEAR_XMLParser
75     * @return string|array
76     */
77    function retrieveData($url, $accept = false, $forcestring = false, $channel = false)
78    {
79        $cacheId = $this->getCacheId($url);
80        if ($ret = $this->useLocalCache($url, $cacheId)) {
81            return $ret;
82        }
83
84        $file = $trieddownload = false;
85        if (!isset($this->_options['offline'])) {
86            $trieddownload = true;
87            $file = $this->downloadHttp($url, $cacheId ? $cacheId['lastChange'] : false, $accept, $channel);
88        }
89
90        if (PEAR::isError($file)) {
91            if ($file->getCode() !== -9276) {
92                return $file;
93            }
94
95            $trieddownload = false;
96            $file = false; // use local copy if available on socket connect error
97        }
98
99        if (!$file) {
100            $ret = $this->getCache($url);
101            if (!PEAR::isError($ret) && $trieddownload) {
102                // reset the age of the cache if the server says it was unmodified
103                $result = $this->saveCache($url, $ret, null, true, $cacheId);
104                if (PEAR::isError($result)) {
105                    return PEAR::raiseError($result->getMessage());
106                }
107            }
108
109            return $ret;
110        }
111
112        if (is_array($file)) {
113            $headers      = $file[2];
114            $lastmodified = $file[1];
115            $content      = $file[0];
116        } else {
117            $headers      = array();
118            $lastmodified = false;
119            $content      = $file;
120        }
121
122        if ($forcestring) {
123            $result = $this->saveCache($url, $content, $lastmodified, false, $cacheId);
124            if (PEAR::isError($result)) {
125                return PEAR::raiseError($result->getMessage());
126            }
127
128            return $content;
129        }
130
131        if (isset($headers['content-type'])) {
132            $content_type = explode(";", $headers['content-type']);
133            $content_type = $content_type[0];
134            switch ($content_type) {
135                case 'text/xml' :
136                case 'application/xml' :
137                case 'text/plain' :
138                    if ($content_type === 'text/plain') {
139                        $check = substr($content, 0, 5);
140                        if ($check !== '<?xml') {
141                            break;
142                        }
143                    }
144
145                    $parser = new PEAR_XMLParser;
146                    PEAR::pushErrorHandling(PEAR_ERROR_RETURN);
147                    $err = $parser->parse($content);
148                    PEAR::popErrorHandling();
149                    if (PEAR::isError($err)) {
150                        return PEAR::raiseError('Invalid xml downloaded from "' . $url . '": ' .
151                            $err->getMessage());
152                    }
153                    $content = $parser->getData();
154                case 'text/html' :
155                default :
156                    // use it as a string
157            }
158        } else {
159            // assume XML
160            $parser = new PEAR_XMLParser;
161            $parser->parse($content);
162            $content = $parser->getData();
163        }
164
165        $result = $this->saveCache($url, $content, $lastmodified, false, $cacheId);
166        if (PEAR::isError($result)) {
167            return PEAR::raiseError($result->getMessage());
168        }
169
170        return $content;
171    }
172
173    function useLocalCache($url, $cacheid = null)
174    {
175        if ($cacheid === null) {
176            $cacheidfile = $this->config->get('cache_dir') . DIRECTORY_SEPARATOR .
177                md5($url) . 'rest.cacheid';
178            if (!file_exists($cacheidfile)) {
179                return false;
180            }
181
182            $cacheid = unserialize(implode('', file($cacheidfile)));
183        }
184
185        $cachettl = $this->config->get('cache_ttl');
186        // If cache is newer than $cachettl seconds, we use the cache!
187        if (time() - $cacheid['age'] < $cachettl) {
188            return $this->getCache($url);
189        }
190
191        return false;
192    }
193
194    function getCacheId($url)
195    {
196        $cacheidfile = $this->config->get('cache_dir') . DIRECTORY_SEPARATOR .
197            md5($url) . 'rest.cacheid';
198
199        if (!file_exists($cacheidfile)) {
200            return false;
201        }
202
203        $ret = unserialize(implode('', file($cacheidfile)));
204        return $ret;
205    }
206
207    function getCache($url)
208    {
209        $cachefile = $this->config->get('cache_dir') . DIRECTORY_SEPARATOR .
210            md5($url) . 'rest.cachefile';
211
212        if (!file_exists($cachefile)) {
213            return PEAR::raiseError('No cached content available for "' . $url . '"');
214        }
215
216        return unserialize(implode('', file($cachefile)));
217    }
218
219    /**
220     * @param string full URL to REST resource
221     * @param string original contents of the REST resource
222     * @param array  HTTP Last-Modified and ETag headers
223     * @param bool   if true, then the cache id file should be regenerated to
224     *               trigger a new time-to-live value
225     */
226    function saveCache($url, $contents, $lastmodified, $nochange = false, $cacheid = null)
227    {
228        $cache_dir   = $this->config->get('cache_dir');
229        $d           = $cache_dir . DIRECTORY_SEPARATOR . md5($url);
230        $cacheidfile = $d . 'rest.cacheid';
231        $cachefile   = $d . 'rest.cachefile';
232
233        if (!is_dir($cache_dir)) {
234            if (System::mkdir(array('-p', $cache_dir)) === false) {
235              return PEAR::raiseError("The value of config option cache_dir ($cache_dir) is not a directory and attempts to create the directory failed.");
236            }
237        }
238
239        if (!is_writeable($cache_dir)) {
240            // If writing to the cache dir is not going to work, silently do nothing.
241            // An ugly hack, but retains compat with PEAR 1.9.1 where many commands
242            // work fine as non-root user (w/out write access to default cache dir).
243            return true;
244        }
245
246        if ($cacheid === null && $nochange) {
247            $cacheid = unserialize(implode('', file($cacheidfile)));
248        }
249
250        $idData = serialize(array(
251            'age'        => time(),
252            'lastChange' => ($nochange ? $cacheid['lastChange'] : $lastmodified),
253        ));
254
255        $result = $this->saveCacheFile($cacheidfile, $idData);
256        if (PEAR::isError($result)) {
257            return $result;
258        } elseif ($nochange) {
259            return true;
260        }
261
262        $result = $this->saveCacheFile($cachefile, serialize($contents));
263        if (PEAR::isError($result)) {
264            if (file_exists($cacheidfile)) {
265              @unlink($cacheidfile);
266            }
267
268            return $result;
269        }
270
271        return true;
272    }
273
274    function saveCacheFile($file, $contents)
275    {
276        $len = strlen($contents);
277
278        $cachefile_fp = @fopen($file, 'xb'); // x is the O_CREAT|O_EXCL mode
279        if ($cachefile_fp !== false) { // create file
280            if (fwrite($cachefile_fp, $contents, $len) < $len) {
281                fclose($cachefile_fp);
282                return PEAR::raiseError("Could not write $file.");
283            }
284        } else { // update file
285            $cachefile_fp = @fopen($file, 'r+b'); // do not truncate file
286            if (!$cachefile_fp) {
287                return PEAR::raiseError("Could not open $file for writing.");
288            }
289
290            if (OS_WINDOWS) {
291                $not_symlink     = !is_link($file); // see bug #18834
292            } else {
293                $cachefile_lstat = lstat($file);
294                $cachefile_fstat = fstat($cachefile_fp);
295                $not_symlink     = $cachefile_lstat['mode'] == $cachefile_fstat['mode']
296                                   && $cachefile_lstat['ino']  == $cachefile_fstat['ino']
297                                   && $cachefile_lstat['dev']  == $cachefile_fstat['dev']
298                                   && $cachefile_fstat['nlink'] === 1;
299            }
300
301            if ($not_symlink) {
302                ftruncate($cachefile_fp, 0); // NOW truncate
303                if (fwrite($cachefile_fp, $contents, $len) < $len) {
304                    fclose($cachefile_fp);
305                    return PEAR::raiseError("Could not write $file.");
306                }
307            } else {
308                fclose($cachefile_fp);
309                $link = function_exists('readlink') ? readlink($file) : $file;
310                return PEAR::raiseError('SECURITY ERROR: Will not write to ' . $file . ' as it is symlinked to ' . $link . ' - Possible symlink attack');
311            }
312        }
313
314        fclose($cachefile_fp);
315        return true;
316    }
317
318    /**
319     * Efficiently Download a file through HTTP.  Returns downloaded file as a string in-memory
320     * This is best used for small files
321     *
322     * If an HTTP proxy has been configured (http_proxy PEAR_Config
323     * setting), the proxy will be used.
324     *
325     * @param string  $url       the URL to download
326     * @param string  $save_dir  directory to save file in
327     * @param false|string|array $lastmodified header values to check against for caching
328     *                           use false to return the header values from this download
329     * @param false|array $accept Accept headers to send
330     * @return string|array  Returns the contents of the downloaded file or a PEAR
331     *                       error on failure.  If the error is caused by
332     *                       socket-related errors, the error object will
333     *                       have the fsockopen error code available through
334     *                       getCode().  If caching is requested, then return the header
335     *                       values.
336     *
337     * @access public
338     */
339    function downloadHttp($url, $lastmodified = null, $accept = false, $channel = false)
340    {
341        static $redirect = 0;
342        // always reset , so we are clean case of error
343        $wasredirect = $redirect;
344        $redirect = 0;
345
346        $info = parse_url($url);
347        if (!isset($info['scheme']) || !in_array($info['scheme'], array('http', 'https'))) {
348            return PEAR::raiseError('Cannot download non-http URL "' . $url . '"');
349        }
350
351        if (!isset($info['host'])) {
352            return PEAR::raiseError('Cannot download from non-URL "' . $url . '"');
353        }
354
355        $host   = isset($info['host']) ? $info['host'] : null;
356        $port   = isset($info['port']) ? $info['port'] : null;
357        $path   = isset($info['path']) ? $info['path'] : null;
358        $schema = (isset($info['scheme']) && $info['scheme'] == 'https') ? 'https' : 'http';
359
360        $proxy = new PEAR_Proxy($this->config);
361
362        if (empty($port)) {
363            $port = (isset($info['scheme']) && $info['scheme'] == 'https')  ? 443 : 80;
364        }
365
366        if ($proxy->isProxyConfigured() && $schema === 'http') {
367            $request = "GET $url HTTP/1.1\r\n";
368        } else {
369            $request = "GET $path HTTP/1.1\r\n";
370        }
371
372        $request .= "Host: $host\r\n";
373        $ifmodifiedsince = '';
374        if (is_array($lastmodified)) {
375            if (isset($lastmodified['Last-Modified'])) {
376                $ifmodifiedsince = 'If-Modified-Since: ' . $lastmodified['Last-Modified'] . "\r\n";
377            }
378
379            if (isset($lastmodified['ETag'])) {
380                $ifmodifiedsince .= "If-None-Match: $lastmodified[ETag]\r\n";
381            }
382        } else {
383            $ifmodifiedsince = ($lastmodified ? "If-Modified-Since: $lastmodified\r\n" : '');
384        }
385
386        $request .= $ifmodifiedsince .
387            "User-Agent: PEAR/@package_version@/PHP/" . PHP_VERSION . "\r\n";
388
389        $username = $this->config->get('username', null, $channel);
390        $password = $this->config->get('password', null, $channel);
391
392        if ($username && $password) {
393            $tmp = base64_encode("$username:$password");
394            $request .= "Authorization: Basic $tmp\r\n";
395        }
396
397        $proxyAuth = $proxy->getProxyAuth();
398        if ($proxyAuth) {
399            $request .= 'Proxy-Authorization: Basic ' .
400                $proxyAuth . "\r\n";
401        }
402
403        if ($accept) {
404            $request .= 'Accept: ' . implode(', ', $accept) . "\r\n";
405        }
406
407        $request .= "Accept-Encoding:\r\n";
408        $request .= "Connection: close\r\n";
409        $request .= "\r\n";
410
411        $secure = ($schema == 'https');
412        $fp = $proxy->openSocket($host, $port, $secure);
413        if (PEAR::isError($fp)) {
414            return $fp;
415        }
416
417        fwrite($fp, $request);
418
419        $headers = array();
420        $reply   = 0;
421        while ($line = trim(fgets($fp, 1024))) {
422            if (preg_match('/^([^:]+):\s+(.*)\s*\\z/', $line, $matches)) {
423                $headers[strtolower($matches[1])] = trim($matches[2]);
424            } elseif (preg_match('|^HTTP/1.[01] ([0-9]{3}) |', $line, $matches)) {
425                $reply = (int)$matches[1];
426                if ($reply == 304 && ($lastmodified || ($lastmodified === false))) {
427                    return false;
428                }
429
430                if (!in_array($reply, array(200, 301, 302, 303, 305, 307))) {
431                    return PEAR::raiseError("File $schema://$host:$port$path not valid (received: $line)");
432                }
433            }
434        }
435
436        if ($reply != 200) {
437            if (!isset($headers['location'])) {
438                return PEAR::raiseError("File $schema://$host:$port$path not valid (redirected but no location)");
439            }
440
441            if ($wasredirect > 4) {
442                return PEAR::raiseError("File $schema://$host:$port$path not valid (redirection looped more than 5 times)");
443            }
444
445            $redirect = $wasredirect + 1;
446            return $this->downloadHttp($headers['location'], $lastmodified, $accept, $channel);
447        }
448
449        $length = isset($headers['content-length']) ? $headers['content-length'] : -1;
450
451        $data = '';
452        while ($chunk = @fread($fp, 8192)) {
453            $data .= $chunk;
454        }
455        fclose($fp);
456
457        if ($lastmodified === false || $lastmodified) {
458            if (isset($headers['etag'])) {
459                $lastmodified = array('ETag' => $headers['etag']);
460            }
461
462            if (isset($headers['last-modified'])) {
463                if (is_array($lastmodified)) {
464                    $lastmodified['Last-Modified'] = $headers['last-modified'];
465                } else {
466                    $lastmodified = $headers['last-modified'];
467                }
468            }
469
470            return array($data, $lastmodified, $headers);
471        }
472
473        return $data;
474    }
475}
476