~azzar1/unity/add-show-desktop-key

#!/usr/bin/python

# IVLE - Informatics Virtual Learning Environment

# Copyright (C) 2007-2008 The University of Melbourne

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

# Script: interpretservice

# Author: David Coles

# Date:   6/3/2007

# A CGI script for interpreting files.

import mimetypes

import os

import sys

import StringIO

import urlparse

import subprocess

from ivle import (cgirequest, studpath)

import ivle.conf

import ivle.conf.mimetypes

import ivle.conf.app

import ivle.conf.app.server

# XXX: using dirname because we don't have path config in the jailconf.

serveservice_path = os.path.join(os.path.dirname(__file__), 'serveservice')

def determine_file_type(filename):

    filetype = mimetypes.guess_type(filename)[0]

    if filetype is None:

         filetype = ivle.conf.mimetypes.default_mimetype

    return filetype

req = cgirequest.CGIRequest()

req.install_error_handler()

python = "/usr/bin/python"

# Work out the parts of the URL

urlpath = urlparse.urlparse(req.path)[2]

filename = studpath.url_to_jailpaths(urlpath)[2]

path_info = ''

if filename is None:

    req.throw_error(req.HTTP_NOT_FOUND, "The path specified is invalid.")

if not os.access(filename, os.F_OK):

    # The given path doesn't exist. CGI lets us backtrack and put the path

    # elements through which we pass into PATH_INFO, so we try that.

    while not os.access(filename, os.F_OK):

        filename, path_info_frag = os.path.split(filename)

        # os.path.join tacks a / on the end even if the second fragment is

        # empty, which we don't want.

        if len(path_info) > 0:

            path_info = os.path.join(path_info_frag, path_info)

        else:

            path_info = path_info_frag

    # PATH_INFO is meant to start with a /.

    path_info = os.path.join(os.sep, path_info)

    # We now have a file that exists, but is it something that we're allowed

    # to execute? If not, we should 404 anyway.

    if determine_file_type(filename) not in ivle.conf.app.server.interpreters:

        req.throw_error(req.HTTP_NOT_FOUND,

            "The specified file (%s) does not exist." % urlpath)

path = os.path.split(filename)[0]

# Everything should be done from the same directory as the script

try:

    os.chdir(path)

except OSError:

    req.throw_error(req.HTTP_NOT_FOUND,

        "The specified file (%s) does not exist." % urlpath)

# Search the path for modules first

sys.path[0] = path

# Now we have lots of fun mangling environment variables to fix PATH_INFO

# and related stuff.

os.environ['PATH_INFO'] = path_info

if len(path_info) > 0:

    os.environ['SCRIPT_NAME'] = os.environ['SCRIPT_NAME'][:-len(path_info)]

# Set PATH_TRANSLATED. We trim the leading / from path_info or things go bad.

path_translated = studpath.url_to_jailpaths(path_info[1:])[2]

if path_translated is not None:

    if len(path_translated) == 0 or path_translated[0] != os.sep:

        path_translated = os.sep + path_translated

    os.environ['PATH_TRANSLATED'] = path_translated

if not os.access(filename, os.R_OK):

    req.throw_error(req.HTTP_NOT_FOUND,

        "The specified file (%s) does not exist." % urlpath)

elif os.path.isdir(filename):

    # 403 Forbidden error for visiting a directory

    # (Not giving a directory listing, since this can be seen by

    # the world at large. Directory contents are private).

    req.throw_error(req.HTTP_FORBIDDEN,

        "The path specified is a directory.")

elif determine_file_type(filename) in ivle.conf.app.server.interpreters:

    # We'll save on a fork and execute in this python process

    # Let exceptions blow up normally again

    sys.excepthook = sys.__excepthook__

    execfile(filename, {})

    # Non-Python process should probably use something like

    # subprocess.call([python, filename])

else:

    # Otherwise, use the blacklist/whitelist to see if this file should be

    # served or disallowed

    if (ivle.conf.app.server.blacklist_served_filetypes and \

            determine_file_type(filename) in \

            ivle.conf.app.server.served_filetypes_blacklist) or \

        (ivle.conf.app.server.served_filetypes_whitelist and \

            determine_file_type(filename) not in \

            ivle.conf.app.server.served_filetypes_whitelist):

        req.throw_error(req.HTTP_FORBIDDEN,

            "Files of this type are not allowed to be served.")

    execfile(serveservice_path)