1<?php
2/**
3 * Functions used by lib/exe/fetch.php
4 * (not included by other parts of dokuwiki)
5 */
6
7/**
8 * Set headers and send the file to the client
9 *
10 * The $cache parameter influences how long files may be kept in caches, the $public parameter
11 * influences if this caching may happen in public proxis or in the browser cache only FS#2734
12 *
13 * This function will abort the current script when a 304 is sent or file sending is handled
14 * through x-sendfile
15 *
16 * @author Andreas Gohr <andi@splitbrain.org>
17 * @author Ben Coburn <btcoburn@silicodon.net>
18 * @author Gerry Weissbach <dokuwiki@gammaproduction.de>
19 *
20 * @param string $file   local file to send
21 * @param string $mime   mime type of the file
22 * @param bool   $dl     set to true to force a browser download
23 * @param int    $cache  remaining cache time in seconds (-1 for $conf['cache'], 0 for no-cache)
24 * @param bool   $public is this a public ressource or a private one?
25 * @param string $orig   original file to send - the file name will be used for the Content-Disposition
26 */
27function sendFile($file, $mime, $dl, $cache, $public = false, $orig = null) {
28    global $conf;
29    // send mime headers
30    header("Content-Type: $mime");
31
32    // calculate cache times
33    if($cache == -1) {
34        $maxage  = max($conf['cachetime'], 3600); // cachetime or one hour
35        $expires = time() + $maxage;
36    } else if($cache > 0) {
37        $maxage  = $cache; // given time
38        $expires = time() + $maxage;
39    } else { // $cache == 0
40        $maxage  = 0;
41        $expires = 0; // 1970-01-01
42    }
43
44    // smart http caching headers
45    if($maxage) {
46        if($public) {
47            // cache publically
48            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
49            header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.$maxage);
50        } else {
51            // cache in browser
52            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
53            header('Cache-Control: private, no-transform, max-age='.$maxage);
54        }
55    } else {
56        // no cache at all
57        header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
58        header('Cache-Control: no-cache, no-transform');
59    }
60
61    //send important headers first, script stops here if '304 Not Modified' response
62    $fmtime = @filemtime($file);
63    http_conditionalRequest($fmtime);
64
65    // Use the current $file if is $orig is not set.
66    if ( $orig == null ) {
67        $orig = $file;
68    }
69
70    //download or display?
71    if ($dl) {
72        header('Content-Disposition: attachment;' . rfc2231_encode(
73                'filename', \dokuwiki\Utf8\PhpString::basename($orig)) . ';'
74        );
75    } else {
76        header('Content-Disposition: inline;' . rfc2231_encode(
77                'filename', \dokuwiki\Utf8\PhpString::basename($orig)) . ';'
78        );
79    }
80
81    //use x-sendfile header to pass the delivery to compatible webservers
82    http_sendfile($file);
83
84    // send file contents
85    $fp = @fopen($file, "rb");
86    if($fp) {
87        http_rangeRequest($fp, filesize($file), $mime);
88    } else {
89        http_status(500);
90        print "Could not read $file - bad permissions?";
91    }
92}
93
94/**
95 * Try an rfc2231 compatible encoding. This ensures correct
96 * interpretation of filenames outside of the ASCII set.
97 * This seems to be needed for file names with e.g. umlauts that
98 * would otherwise decode wrongly in IE.
99 *
100 * There is no additional checking, just the encoding and setting the key=value for usage in headers
101 *
102 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
103 * @param string $name      name of the field to be set in the header() call
104 * @param string $value     value of the field to be set in the header() call
105 * @param string $charset   used charset for the encoding of value
106 * @param string $lang      language used.
107 * @return string           in the format " name=value" for values WITHOUT special characters
108 * @return string           in the format " name*=charset'lang'value" for values WITH special characters
109 */
110function rfc2231_encode($name, $value, $charset='utf-8', $lang='en') {
111    $internal = preg_replace_callback(
112        '/[\x00-\x20*\'%()<>@,;:\\\\"\/[\]?=\x80-\xFF]/',
113        function ($match) {
114            return rawurlencode($match[0]);
115        },
116        $value
117    );
118    if ( $value != $internal ) {
119        return ' '.$name.'*='.$charset."'".$lang."'".$internal;
120    } else {
121        return ' '.$name.'="'.$value.'"';
122    }
123}
124
125/**
126 * Check for media for preconditions and return correct status code
127 *
128 * READ: MEDIA, MIME, EXT, CACHE
129 * WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
130 *
131 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
132 *
133 * @param string $media  reference to the media id
134 * @param string $file   reference to the file variable
135 * @param string $rev
136 * @param int    $width
137 * @param int    $height
138 * @return array as array(STATUS, STATUSMESSAGE)
139 */
140function checkFileStatus(&$media, &$file, $rev = '', $width=0, $height=0) {
141    global $MIME, $EXT, $CACHE, $INPUT;
142
143    //media to local file
144    if(media_isexternal($media)) {
145        //check token for external image and additional for resized and cached images
146        if(media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
147            return array(412, 'Precondition Failed');
148        }
149        //handle external images
150        if(strncmp($MIME, 'image/', 6) == 0) $file = media_get_from_URL($media, $EXT, $CACHE);
151        if(!$file) {
152            //download failed - redirect to original URL
153            return array(302, $media);
154        }
155    } else {
156        $media = cleanID($media);
157        if(empty($media)) {
158            return array(400, 'Bad request');
159        }
160        // check token for resized images
161        if (($width || $height) && media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
162            return array(412, 'Precondition Failed');
163        }
164
165        //check permissions (namespace only)
166        if(auth_quickaclcheck(getNS($media).':X') < AUTH_READ) {
167            return array(403, 'Forbidden');
168        }
169        $file = mediaFN($media, $rev);
170    }
171
172    //check file existance
173    if(!file_exists($file)) {
174        return array(404, 'Not Found');
175    }
176
177    return array(200, null);
178}
179
180/**
181 * Returns the wanted cachetime in seconds
182 *
183 * Resolves named constants
184 *
185 * @author  Andreas Gohr <andi@splitbrain.org>
186 *
187 * @param string $cache
188 * @return int cachetime in seconds
189 */
190function calc_cache($cache) {
191    global $conf;
192
193    if(strtolower($cache) == 'nocache') return 0; //never cache
194    if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
195    return -1; //cache endless
196}
197