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# IVLE
# 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
# App: server
# Author: Tom Conway, Matt Giuca
# Date: 13/12/2007
# Serves content to the user (acting as a web server for students files).
# For most file types we just serve the static file, but
# for python files, we evaluate the python script inside
# our safe execution environment.
import os
import mimetypes
import cjson
from ivle import (util, studpath, interpret)
import ivle.conf
from ivle.database import User
from ivle.webapp.base.views import BaseView
from ivle.webapp.base.plugins import ViewPlugin
from ivle.webapp.errors import NotFound, Unauthorized, Forbidden
serveservice_path = os.path.join(ivle.conf.share_path, 'services/serveservice')
interpretservice_path = os.path.join(ivle.conf.share_path,
'services/interpretservice')
# Serve all files as application/octet-stream so the browser presents them as
# a download.
default_mimetype = "application/octet-stream"
zip_mimetype = "application/zip"
class ServeView(BaseView):
def __init__(self, req, path):
self.path = path
def authorize(self, req):
return req.user is not None
def render(self, req):
"""Handler for the Server application which serves pages."""
# Get the username of the student whose work we are browsing, and the
# path on the local machine where the file is stored.
(login, jail, path) = studpath.url_to_jailpaths(self.path)
owner = User.get_by_login(req.store, login)
if not owner:
# There is no user.
raise NotFound()
self.serve(req, owner, jail, path)
def serve(self, req, owner, jail, path):
serve_file(req, owner, jail, path)
class DownloadView(ServeView):
def serve(self, req, owner, jail, path):
serve_file(req, owner, jail, path, download=True)
def authorize(req):
"""Given a request, checks whether req.username is allowed to
access req.path. Returns True on authorization success, False on failure.
"""
# TODO: Reactivate public mode.
#if req.publicmode:
# Public mode authorization: any user can access any other user's
# files, BUT the accessed file needs to have its "ivle:published" flag
# turned on in the SVN status.
# studpath.authorize_public(req)
# Private mode authorization: standard (only logged in user can access
# their own files, and can access all of them).
return studpath.authorize(req, req.user)
def serve_file(req, owner, jail, path, download=False):
"""Serves a file, using one of three possibilities: interpreting the file,
serving it directly, or denying it and returning a 403 Forbidden error.
No return value. Writes to req (possibly throwing a server error exception
using req.throw_error).
req: An IVLE request object.
owner: The user who owns the file being served.
jail: The user's jail.
path: Filename in the jail.
download: Should the file be viewed in browser or downloaded
"""
# We need a no-op trampoline run to ensure that the jail is mounted.
# Otherwise we won't be able to authorise for public mode!
noop_object = interpret.interpreter_objects["noop"]
user_jail_dir = os.path.join(ivle.conf.jail_base, owner.login)
interpret.interpret_file(req, owner, user_jail_dir, '', noop_object)
# Authorize access. If failure, this throws a HTTP_FORBIDDEN error.
if not authorize(req):
raise Unauthorized()
args = [path]
if download:
args.insert(0, '-d')
# TODO: Download. Content-Disposition, etc.
(out, err) = ivle.interpret.execute_raw(req.user, jail, '/home',
os.path.join(ivle.conf.share_path, 'services/serveservice'),
args)
assert not err
# Remove the JSON from the front of the response, and decode it.
json = out.split('\n', 1)[0]
out = out[len(json) + 1:]
response = cjson.decode(json)
if 'error' in response:
if response['error'] == 'not-found':
raise NotFound()
elif response['error'] in ('is-directory', 'forbidden'):
raise Forbidden()
else:
raise AssertionError('Unknown error from serveservice: %s' %
response['error'])
if download:
req.headers_out["Content-Disposition"] = \
"attachment; filename=%s" % response['name']
req.content_type = response['type']
req.write(out)
class Plugin(ViewPlugin):
urls = [
('serve/*path', ServeView),
('download/*path', DownloadView),
]
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