1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
# 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
from ivle import (util, studpath, interpret)
import ivle.conf
from ivle.database import User
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"
def handle(req):
"""Handler for the Server application which serves pages."""
req.write_html_head_foot = False
# Get the username of the student whose work we are browsing, and the path
# on the local machine where the file is stored.
(login, path) = studpath.url_to_local(req.path)
owner = User.get_by_login(req.store, login)
if not owner:
# There is no user.
req.throw_error(req.HTTP_NOT_FOUND,
"The path specified is invalid.")
serve_file(req, owner, path)
def authorize(req):
"""Given a request, checks whether req.username is allowed to
access req.path. Returns None on authorization success. Raises
HTTP_FORBIDDEN on failure.
"""
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)
else:
# Private mode authorization: standard (only logged in user can access
# their own files, and can access all of them).
studpath.authorize(req)
def serve_file(req, owner, filename, 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.
filename: Filename in the local file system.
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.
authorize(req)
# Jump into the jail
interp_object = interpret.interpreter_objects["cgi-python"]
if download:
req.headers_out["Content-Disposition"] = "attachment"
interpret.interpret_file(req, owner, user_jail_dir,
serveservice_path, interp_object, gentle=False)
else:
interpret.interpret_file(req, owner, user_jail_dir,
interpretservice_path, interp_object, gentle=True)
def serve_file_direct(req, filename, type):
"""Serves a file by directly writing it out to the response.
req: An IVLE request object.
filename: Filename in the local file system.
type: String. Mime type to serve the file with.
"""
if not os.access(filename, os.R_OK):
req.throw_error(req.HTTP_NOT_FOUND,
"The specified file does not exist.")
req.content_type = type
req.sendfile(filename)
|