アップロード不可能な拡張子を指定してファイルアップロードする

CodeIgniterのファイルアップロードクラスはアップロード可能な拡張子を指定することができるけど、逆にアップロード不可能な拡張子を指定できない。
そこでCI_Uploadクラスを拡張して、アップロード不可能な拡張子を指定できるようにしてみる。

MY_Upload.php

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class MY_Upload extends CI_Upload {
    
        public $disallowed_types                = "";

	// --------------------------------------------------------------------

	/**
	 * Initialize preferences
	 *
	 * @param	array
	 * @return	void
	 */
	public function initialize($config = array())
	{
		$defaults = array(
							'max_size'			=> 0,
							'max_width'			=> 0,
							'max_height'		=> 0,
							'max_filename'		=> 0,
							'allowed_types'		=> "",
                                                        'disallowed_types'      => "",
							'file_temp'			=> "",
							'file_name'			=> "",
							'orig_name'			=> "",
							'file_type'			=> "",
							'file_size'			=> "",
							'file_ext'			=> "",
							'upload_path'		=> "",
							'overwrite'			=> FALSE,
							'encrypt_name'		=> FALSE,
							'is_image'			=> FALSE,
							'image_width'		=> '',
							'image_height'		=> '',
							'image_type'		=> '',
							'image_size_str'	=> '',
							'error_msg'			=> array(),
							'mimes'				=> array(),
							'remove_spaces'		=> TRUE,
							'xss_clean'			=> FALSE,
							'temp_prefix'		=> "temp_file_",
							'client_name'		=> ''
						);


		foreach ($defaults as $key => $val)
		{
			if (isset($config[$key]))
			{
				$method = 'set_'.$key;
				if (method_exists($this, $method))
				{
					$this->$method($config[$key]);
				}
				else
				{
					$this->$key = $config[$key];
				}
			}
			else
			{
				$this->$key = $val;
			}
		}

		// if a file_name was provided in the config, use it instead of the user input
		// supplied file name for all uploads until initialized again
		$this->_file_name_override = $this->file_name;
	}

	// --------------------------------------------------------------------


	/**
	 * Verify that the filetype is allowed
	 *
	 * @return	bool
	 */
	public function is_allowed_filetype($ignore_mime = FALSE)
	{
            // if allowed file type list is not defined
            if (count($this->allowed_types) == 0 OR ! is_array($this->allowed_types)) {
                // if disallowed file type list is not defined
                if (count($this->disallowed_types) == 0 OR ! is_array($this->disallowed_types))
                {
                    return TRUE;
                }
                // check for disallowed file types and return
                // negated because is_disallowed_filetype returns opposite result as this function
                return ! $this->is_disallowed_filetype();
            }

            // proceed as usual with allowed file type list check
            return parent::is_allowed_filetype($ignore_mime);

	}

	// --------------------------------------------------------------------

        
	/**
	 * Set Allowed File Types
	 *
	 * @param	string
	 * @return	void
	 */
	public function set_disallowed_types($types)
	{
		if ( ! is_array($types) && $types == '*')
		{
			$this->disallowed_types = '*';
			return;
		}
		$this->disallowed_types = explode('|', $types);
	}
        
        // --------------------------------------------------------------------             

	/**
	 * Verify that the filetype is disallowed
	 *
	 * @return	bool
	 */
	public function is_disallowed_filetype($ignore_mime = FALSE)
	{
		if ($this->disallowed_types == '*')
		{
			return TRUE;
		}

		if (count($this->disallowed_types) == 0 OR ! is_array($this->disallowed_types))
		{
			return FALSE;
		}

		$ext = strtolower(ltrim($this->file_ext, '.'));

		if ( in_array($ext, $this->disallowed_types))
		{
			return TRUE;
		}
                
		return FALSE;
	}         
}

以上のファイルとapplication/librariesに配置すればOK。

設定ファイルは以下のようにアップロード不可能な拡張子のみ記述するようにしておく。

<?php

$config['upload_path'] = APPPATH . '../uploads/';
$config['disallowed_types'] = 'gif|jpg|png';
$config['max_size']	= '100';
$config['max_width'] = '1024';
$config['max_height'] = '768';

こんな感じっすかね？

---

参考: CODEIGNITER FILE UPLOAD: SETTING DISALLOWED FILE TYPES