root/releases/0.6rc2/lib/uploadlib.php

<?php

/**
 * uploadlib.php - This class handles all aspects of fileuploading
 *
 * @author Penny Leach
 * @version 1.5
 * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
 * @package moodlecore
 */


/**
 * This class handles all aspects of fileuploading
 */
class upload_manager {

   /**
    * Array to hold local copies of stuff in $_FILES
    * @var array $files 
    */
    var $files;
   /**
    * Holds all configuration stuff
    * @var array $config 
    */
    var $config;
   /**
    * Keep track of if we're ok
    * (errors for each file are kept in $files['whatever']['uploadlog']
    * @var boolean $status
    */
    var $status;
   /**
    * If we're only getting one file.
    * (for logging and virus notifications)
    * @var string $inputname 
    */
    var $inputname;
   /**
    * If we're given silent=true in the constructor, this gets built 
    * up to hold info about the process.
    * @var string $notify 
    */
    var $notify;

    /**
     * Constructor, sets up configuration stuff so we know how to act.
     *
     * Note: destination not taken as parameter as some modules want to use the insertid in the path and we need to check the other stuff first.
     *
     * @uses $CFG
     * @param string $inputname If this is given the upload manager will only process the file in $_FILES with this name.
     * @param boolean $deleteothers Whether to delete other files in the destination directory (optional, defaults to false)
     * @param boolean $handlecollisions Whether to use {@link handle_filename_collision()} or not. (optional, defaults to false)
     * @param boolean $recoverifmultiple If we come across a virus, or if a file doesn't validate or whatever, do we continue? optional, defaults to true.
     * @param int $maxbytes max bytes for this file {@link get_max_upload_file_size()}.
     * @param boolean $silent Whether to notify errors or not.
     * @param boolean $allownull Whether we care if there's no file when we've set the input name.
     * @param boolean $allownullmultiple Whether we care if there's no files AT ALL  when we've got multiples. This won't complain if we have file 1 and file 3 but not file 2, only for NO FILES AT ALL.
     */
    function upload_manager($inputname='', $deleteothers=false, $handlecollisions=false, $recoverifmultiple=false, $maxbytes=0, $silent=false, $allownull=false, $allownullmultiple=true) {
        
        global $CFG;
        
        $this->config->deleteothers = $deleteothers;
        $this->config->handlecollisions = $handlecollisions;
        $this->config->recoverifmultiple = $recoverifmultiple;
        $this->config->maxbytes = get_max_upload_file_size($maxbytes);
        $this->config->silent = $silent;
        $this->config->allownull = $allownull;
        $this->files = array();
        $this->status = false; 
        $this->inputname = $inputname;
        if (empty($this->inputname)) {
            $this->config->allownull = $allownullmultiple;
        }
    }
    
    /** 
     * Gets all entries out of $_FILES and stores them locally in $files and then
     * checks each one against {@link get_max_upload_file_size()} and calls {@link cleanfilename()} 
     * and scans them for viruses etc.
     * @uses $CFG
     * @uses $_FILES
     * @return boolean
     */
    function preprocess_files() {
        global $CFG;

        foreach ($_FILES as $name => $file) {
            $this->status = true; // only set it to true here so that we can check if this function has been called.
            if (empty($this->inputname) || $name == $this->inputname) { // if we have input name, only process if it matches.
                $file['originalname'] = $file['name']; // do this first for the log.
                $this->files[$name] = $file; // put it in first so we can get uploadlog out in print_upload_log.
                $this->status = $this->validate_file($this->files[$name]); // default to only allowing empty on multiple uploads.
                if (!$this->status && ($this->files[$name]['error'] == 0 || $this->files[$name]['error'] == 4) && ($this->config->allownull || empty($this->inputname))) {
                    // this shouldn't cause everything to stop.. modules should be responsible for knowing which if any are compulsory.
                    continue; 
                }
                if ($this->status && $CFG->runclamonupload) {
                    $this->status = clam_scan_file($this->files[$name]);
                }
                if (!$this->status) {
                    if (!$this->config->recoverifmultiple && count($this->files) > 1) {
                        $a->name = $this->files[$name]['originalname'];
                        $a->problem = $this->files[$name]['uploadlog'];
                        $msg = sprintf(gettext('Your file upload has failed because there was a problem with one of the files, %s.<br /> Here is a log of the problems:<br />%s<br />Not recovering.'), $a->name, $a->problem);
                        if (!$this->config->silent) {
                            notify($msg);
                        }
                        else {
                            $this->notify .= '<br />'. $msg;
                        }
                        $this->status = false;
                        return false;

                    } else if (count($this->files) == 1) {

                        if (!$this->config->silent and !$this->config->allownull) {
                            notify($this->files[$name]['uploadlog']);
                        } else {
                            $this->notify .= '<br />'. $this->files[$name]['uploadlog'];
                        }
                        $this->status = false;
                        return false;
                    }
                }
                else {
                    $newname = clean_filename($this->files[$name]['name']);
                    if ($newname != $this->files[$name]['name']) {
                        $a->oldname = $this->files[$name]['name'];
                        $a->newname = $newname;
                        $this->files[$name]['uploadlog'] .= sprintf(gettext('File was renamed from %s to %s because of invalid characters.'), $a->oldname, $a->newname);
                    }
                    $this->files[$name]['name'] = $newname;
                    $this->files[$name]['clear'] = true; // ok to save.
                }
            }
        }
        if (!is_array($_FILES) || count($_FILES) == 0) {
            return $this->config->allownull;
        }
        $this->status = true;
        return true; // if we've got this far it means that we're recovering so we want status to be ok.
    }

    /**
     * Validates a single file entry from _FILES
     *
     * @param object $file The entry from _FILES to validate
     * @return boolean True if ok.
     */
    function validate_file(&$file) {
        if (empty($file)) {
            return false;
        }
        if (!is_uploaded_file($file['tmp_name']) || $file['size'] == 0) {
            $file['uploadlog'] .= "\n".$this->get_file_upload_error($file);
            return false;
        }
        if ($file['size'] > $this->config->maxbytes) {
            $file['uploadlog'] .= "\n". sprintf(gettext('Sorry, but that file is too big (limit is %s)'), display_size($this->config->maxbytes));
            return false;
        }
        return true;
    }

    /** 
     * Moves all the files to the destination directory.
     *
     * @uses $CFG
     * @uses $USER
     * @param string $destination The destination directory.
     * @return boolean status;
     */
    function save_files($destination) {
        global $CFG, $USER;
        $textlib = textlib_get_instance();
        
        if (!$this->status) { // preprocess_files hasn't been run
            $this->preprocess_files();
        }
        if ($this->status) {
            if (!($textlib->strpos($destination, $CFG->dataroot) === false)) {
                // take it out for giving to make_upload_directory
                $destination = $textlib->substr($destination, $textlib->strlen($CFG->dataroot));
            }

            if ($destination{$textlib->strlen($destination)-1} == '/') { // strip off a trailing / if we have one
                $destination = $textlib->substr($destination, 0, -1);
            }

            if (!make_upload_directory($destination, true)) { //TODO maybe put this function here instead of moodlelib.php now.
                $this->status = false;
                return false;
            }
            
            $destination = $CFG->dataroot .'/'. $destination; // now add it back in so we have a full path

            $exceptions = array(); //need this later if we're deleting other files.

            foreach (array_keys($this->files) as $i) {

                if (!$this->files[$i]['clear']) {
                    // not ok to save
                    continue;
                }

                if ($this->config->handlecollisions) {
                    $this->handle_filename_collision($destination, $this->files[$i]);
                }
                if (move_uploaded_file($this->files[$i]['tmp_name'], $destination.'/'.$this->files[$i]['name'])) {
                    chmod($destination .'/'. $this->files[$i]['name'], $CFG->directorypermissions);
                    $this->files[$i]['fullpath'] = $destination.'/'.$this->files[$i]['name'];
                    $this->files[$i]['uploadlog'] .= "\n".gettext('File uploaded successfully');
                    $this->files[$i]['saved'] = true;
                    $exceptions[] = $this->files[$i]['name'];
                    // now add it to the log (this is important so we know who to notify if a virus is found later on)
                    clam_log_upload($this->files[$i]['fullpath']);
                    $savedsomething=true;
                }
            }
            if ($savedsomething && $this->config->deleteothers) {
                $this->delete_other_files($destination, $exceptions);
            }
        }
        if (empty($savedsomething)) {
            $this->status = false;
            if ((empty($this->config->allownull) && !empty($this->inputname)) || (empty($this->inputname) && empty($this->config->allownullmultiple))) {
                notify(gettext('No file was found - are you sure you selected one to upload?'));
            }
            return false;
        }
        return $this->status;
    }
    
    /**
     * Wrapper function that calls {@link preprocess_files()} and {@link viruscheck_files()} and then {@link save_files()}
     * Modules that require the insert id in the filepath should not use this and call these functions seperately in the required order.
     * @parameter string $destination Where to save the uploaded files to.
     * @return boolean
     */ 
    function process_file_uploads($destination) {
        if ($this->preprocess_files()) {
            return $this->save_files($destination);
        }
        return false;
    }

    /** 
     * Deletes all the files in a given directory except for the files in $exceptions (full paths)
     *
     * @param string $destination The directory to clean up.
     * @param array $exceptions Full paths of files to KEEP.
     */
    function delete_other_files($destination, $exceptions=null) {
        if ($filestodel = get_directory_list($destination)) {
            foreach ($filestodel as $file) {
                if (!is_array($exceptions) || !in_array($file, $exceptions)) {
                    unlink($destination .'/'. $file);
                    $deletedsomething = true;
                }
            }
        }
        if ($deletedsomething) {
            $msg = gettext('The old file(s) in your upload area have been deleted');
            if (!$this->config->silent) {
                notify($msg);
            }
            else {
                $this->notify .= '<br />'. $msg;
            }
        }
    }
    
    /**
     * Handles filename collisions - if the desired filename exists it will rename it according to the pattern in $format
     * @param string $destination Destination directory (to check existing files against)
     * @param object $file Passed in by reference. The current file from $files we're processing.
     * @param string $format The printf style format to rename the file to (defaults to filename_number.extn)
     * @return string The new filename.
     * @todo verify return type - this function does not appear to return anything since $file is passed in by reference
     */
    function handle_filename_collision($destination, &$file, $format='%s_%d.%s') {
        $bits = explode('.', $file['name']);
        // check for collisions and append a nice numberydoo.
        if (file_exists($destination .'/'. $file['name'])) {
            $a->oldname = $file['name'];
            for ($i = 1; true; $i++) {
                $try = sprintf($format, $bits[0], $i, $bits[1]);
                if ($this->check_before_renaming($destination, $try, $file)) {
                    $file['name'] = $try;
                    break;
                }
            }
            $a->newname = $file['name'];
            $file['uploadlog'] .= "\n". sprintf(gettext('File was renamed from %s to %s because there was a filename conflict.'), $a->oldname, $a->newname);
        }
    }
    
    /**
     * This function checks a potential filename against what's on the filesystem already and what's been saved already.
     * @param string $destination Destination directory (to check existing files against)
     * @param string $nametocheck The filename to be compared.
     * @param object $file The current file from $files we're processing.
     * return boolean
     */
    function check_before_renaming($destination, $nametocheck, $file) {
        if (!file_exists($destination .'/'. $nametocheck)) {
            return true;
        }
        if ($this->config->deleteothers) {
            foreach ($this->files as $tocheck) {
                // if we're deleting files anyway, it's not THIS file and we care about it and it has the same name and has already been saved..
                if ($file['tmp_name'] != $tocheck['tmp_name'] && $tocheck['clear'] && $nametocheck == $tocheck['name'] && $tocheck['saved']) {
                    $collision = true;
                }
            }
            if (!$collision) {
                return true;
            }
        }
        return false;
    }

    /**
     * ?
     *
     * @param object $file Passed in by reference. The current file from $files we're processing.
     * @return string
     * @todo Finish documenting this function
     */
    function get_file_upload_error(&$file) {
        
        switch ($file['error']) {
        case 0: // UPLOAD_ERR_OK
            if ($file['size'] > 0) {
                $errmessage = sprintf(gettext('An unknown problem occurred while uploading the file \'%s\' (perhaps it was too large?)'), $file['name']);
            } else {
                $errmessage = gettext('No file was found - are you sure you selected one to upload?'); /// probably a dud file name
            }
            break;
            
        case 1: // UPLOAD_ERR_INI_SIZE
            $errmessage = gettext('Uploaded file exceeded the maximum size limit set by the server');
            break;
            
        case 2: // UPLOAD_ERR_FORM_SIZE
            $errmessage = gettext('Uploaded file exceeded the maximum size limit set by the form');
            break;
            
        case 3: // UPLOAD_ERR_PARTIAL
            $errmessage = gettext('File was only partially uploaded');
            break;
            
        case 4: // UPLOAD_ERR_NO_FILE
            $errmessage = gettext('No file was found - are you sure you selected one to upload?');
            break;
            
        default:
            $errmessage = sprintf(gettext('An unknown problem occurred while uploading the file \'%s\' (perhaps it was too large?)'), $file['name']);
        }
        return $errmessage;
    }
    
    /**
     * prints a log of everything that happened (of interest) to each file in _FILES
     * @param $return - optional, defaults to false (log is echoed)
     */
    function print_upload_log($return=false,$skipemptyifmultiple=false) {
        foreach (array_keys($this->files) as $i => $key) {
            if (count($this->files) > 1 && !empty($skipemptyifmultiple) && $this->files[$key]['error'] == 4) {
                continue;
            }
            $str .= '<strong>'. sprintf(gettext('Upload log for file %u'), $i+1) .' '
                .((!empty($this->files[$key]['originalname'])) ? '('.$this->files[$key]['originalname'].')' : '')
                .'</strong> :'. nl2br($this->files[$key]['uploadlog']) .'<br />';
        }
        if ($return) {
            return $str;
        }
        echo $str;
    }

    /**
     * If we're only handling one file (if inputname was given in the constructor) this will return the (possibly changed) filename of the file.
     @return boolean
     */
    function get_new_filename() {
        if (!empty($this->inputname) && count($this->files) == 1) {
            return $this->files[$this->inputname]['name'];
        }
        return false;
    }

    /** 
     * If we're only handling one file (if input name was given in the constructor) this will return the full path to the saved file.
     * @return boolean
     */
    function get_new_filepath() {
        if (!empty($this->inputname) && count($this->files) == 1) {
            return $this->files[$this->inputname]['fullpath'];
        }
        return false;
    }

    /** 
     * If we're only handling one file (if inputname was given in the constructor) this will return the ORIGINAL filename of the file.
     * @return boolean
     */
    function get_original_filename() {
        if (!empty($this->inputname) && count($this->files) == 1) {
            return $this->files[$this->inputname]['originalname'];
        }
        return false;
    }

    /**
     * If we're only handling on file (if inputname was given in the constructor) this will return the size of the file.
     */
    function get_filesize() {
        if (!empty($this->inputname) && count($this->files) == 1) {
            return $this->files[$this->inputname]['size'];
        }
    }


    /** 
     * This function returns any errors wrapped up in red.
     * @return string
     */
    function get_errors() {
        return $this->notify ;
    }
}

/**************************************************************************************
THESE FUNCTIONS ARE OUTSIDE THE CLASS BECAUSE THEY NEED TO BE CALLED FROM OTHER PLACES.
FOR EXAMPLE CLAM_HANDLE_INFECTED_FILE AND CLAM_REPLACE_INFECTED_FILE USED FROM CRON
UPLOAD_PRINT_FORM_FRAGMENT DOESN'T REALLY BELONG IN THE CLASS BUT CERTAINLY IN THIS FILE
***************************************************************************************/


/**
 * This function prints out a number of upload form elements.
 *
 * @param int $numfiles The number of elements required (optional, defaults to 1)
 * @param array $names Array of element names to use (optional, defaults to FILE_n)
 * @param array $descriptions Array of strings to be printed out before each file bit.
 * @param boolean $uselabels -Whether to output text fields for file descriptions or not (optional, defaults to false)
 * @param array $labelnames Array of element names to use for labels (optional, defaults to LABEL_n)
 * @param int $maxbytes used to calculate upload max size ( using {@link get_max_upload_file_size})
 * @param boolean $return -Whether to return the string (defaults to false - string is echoed)
 * @return string Form returned as string if $return is true
 */ 
function upload_print_form_fragment($numfiles=1, $names=null, $descriptions=null, $uselabels=false, $labelnames=null, $maxbytes=0, $return=false) {
    global $CFG;
    $maxbytes = get_max_upload_file_size($CFG->maxbytes, $coursebytes, $maxbytes);
    $str = '<input type="hidden" name="MAX_FILE_SIZE" value="'. $maxbytes .'" />'."\n";
    for ($i = 0; $i < $numfiles; $i++) {
        if (is_array($descriptions) && !empty($descriptions[$i])) {