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# IVLE - Informatics Virtual Learning Environment
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# Copyright (C) 2007-2009 The University of Melbourne
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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# Author: Matt Giuca, Will Grant
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This is a mod_python handler program. The correct way to call it is to have
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Apache send all requests to be handled by the module 'dispatch'.
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Top-level handler. Handles all requests to all pages in IVLE.
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Handles authentication and delegates to views for authorization,
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then passes the request along to the appropriate view.
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from ivle.dispatch.request import Request
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import ivle.webapp.security
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from ivle.webapp.base.plugins import ViewPlugin, PublicViewPlugin
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from ivle.webapp.base.xhtml import XHTMLView, XHTMLErrorView
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from ivle.webapp.errors import BadRequest, HTTPError, NotFound, Unauthorized
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from ivle.webapp.publisher import Publisher, PublishingError
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from ivle.webapp import ApplicationRoot
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config = ivle.config.Config()
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class ObjectPermissionCheckingPublisher(Publisher):
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"""A specialised publisher that checks object permissions.
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This publisher verifies that the user holds any permission at all
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on the model objects through which the resolution path passes. If
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no permission is held, resolution is aborted with an Unauthorized
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IMPORTANT: This does NOT check view permissions. It only checks
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the objects in between the root and the view, exclusive!
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def traversed_to_object(self, obj):
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"""Check that the user has any permission at all over the object."""
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if (hasattr(obj, 'get_permissions') and
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len(obj.get_permissions(self.root.user, config)) == 0):
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# Indicate the forbidden object if this is an admin.
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if self.root.user and self.root.user.admin:
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raise Unauthorized('Unauthorized: %s' % obj)
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def generate_publisher(view_plugins, root, publicmode=False):
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Build a Mapper object for doing URL matching using 'routes', based on the
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given plugin registry.
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r = ObjectPermissionCheckingPublisher(root=root)
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r.add_set_switch('api', 'api')
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view_attr = 'public_views'
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forward_route_attr = 'public_forward_routes'
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reverse_route_attr = 'public_reverse_routes'
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forward_route_attr = 'forward_routes'
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reverse_route_attr = 'reverse_routes'
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for plugin in view_plugins:
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if hasattr(plugin, forward_route_attr):
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for fr in getattr(plugin, forward_route_attr):
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# An annotated function can also be passed in directly.
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if hasattr(fr, '_forward_route_meta'):
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r.add_forward_func(fr)
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if hasattr(plugin, reverse_route_attr):
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for rr in getattr(plugin, reverse_route_attr):
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# An annotated function can also be passed in directly.
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if hasattr(rr, '_reverse_route_src'):
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r.add_reverse_func(rr)
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if hasattr(plugin, view_attr):
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for v in getattr(plugin, view_attr):
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def handler(apachereq):
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"""Handles an HTTP request.
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Intended to be called by mod_python, as a handler.
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@param apachereq: An Apache request object.
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# Make the request object into an IVLE request which can be given to views
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req = Request(apachereq, config)
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req.publisher = generate_publisher(
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config.plugin_index[ViewPlugin], ApplicationRoot(req),
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publicmode=req.publicmode)
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obj, viewcls, subpath = req.publisher.resolve(req.uri.decode('utf-8'))
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# We 404 if we have a subpath but the view forbids it.
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if not viewcls.subpath_allowed and subpath:
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# Instantiate the view, which should be a BaseView class
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view = viewcls(req, obj, subpath)
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# Check that the request (mainly the user) is permitted to access
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if not view.authorize(req):
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# Indicate the forbidden object if this is an admin.
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if req.user and req.user.admin:
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raise Unauthorized('Unauthorized: %s' % view)
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# Non-GET requests from other sites leave us vulnerable to
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referer = req.headers_in.get('Referer')
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if (referer is None or
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urlparse.urlparse(req.headers_in.get('Referer')).netloc !=
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if req.method != 'GET' and not view.offsite_posts_allowed:
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"Non-GET requests from external sites are forbidden "
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"for security reasons.")
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# A view explicitly raised an HTTP error. Respect it.
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# Try to find a custom error view.
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if hasattr(viewcls, 'get_error_view'):
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errviewcls = viewcls.get_error_view(e)
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errviewcls = XHTMLView.get_error_view(e)
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errview = errviewcls(req, e, obj)
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except mod_python.apache.SERVER_RETURN:
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# A mod_python-specific Apache error.
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# XXX: We need to raise these because req.throw_error() uses them.
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# Remove this after Google Code issue 117 is fixed.
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# A non-HTTPError appeared. We have an unknown exception. Panic.
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handle_unknown_exception(req, *sys.exc_info())
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# Commit the transaction if we have a store open.
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except Unauthorized, e:
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# Resolution failed due to a permission check. Display a pretty
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# error, or maybe a login page.
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XHTMLView.get_error_view(e)(req, e, req.publisher.root).render(req)
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except PublishingError, e:
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if req.user and req.user.admin:
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XHTMLErrorView(req, NotFound('Not found: ' +
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str(e.args)), e[0]).render(req)
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XHTMLErrorView(req, NotFound(), e[0]).render(req)
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# Make sure we close the store.
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def handle_unknown_exception(req, exc_type, exc_value, exc_traceback):
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Given an exception that has just been thrown from IVLE, print its details
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This is a full handler. It assumes nothing has been written, and writes a
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req: May be EITHER an IVLE req or an Apache req.
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The handler code may pass an apache req if an exception occurs before
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the IVLE request is created.
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req.content_type = "text/html"
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logfile = os.path.join(config['paths']['logs'], 'ivle_error.log')
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req.status = mod_python.apache.HTTP_INTERNAL_SERVER_ERROR
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publicmode = req.publicmode
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except AttributeError:
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login = req.user.login
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except AttributeError:
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for h in logging.getLogger().handlers:
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logging.getLogger().removeHandler(h)
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logging.basicConfig(level=logging.INFO,
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format='%(asctime)s %(levelname)s: ' +
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'(HTTP: ' + str(req.status) +
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', Ref: ' + str(login) + '@' +
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str(socket.gethostname()) + str(req.uri) +
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# A "bad" error message. We shouldn't get here unless IVLE
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# misbehaves (which is currently very easy, if things aren't set up
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# Write the traceback.
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# We need to special-case IVLEJailError, as we can get another
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# almost-exception out of it.
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if exc_type is util.IVLEJailError:
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tb = 'Exception information extracted from IVLEJailError:\n'
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tb += urllib.unquote(exc_value.info)
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tb = ''.join(traceback.format_exception(exc_type, exc_value,
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logging.error('\n' + tb)
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# Error messages are only displayed is the user is NOT a student,
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# or if there has been a problem logging the error message
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show_errors = (not publicmode) and ((login and req.user.admin) or logfail)
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req.write("""<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head><title>IVLE Internal Server Error</title></head>
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<h1>IVLE Internal Server Error</h1>
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<p>An error has occured which is the fault of the IVLE developers or
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req.write("Please report this issue to the server administrators, "
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"along with the following information.")
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req.write("Details have been logged for further examination.")
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req.write("<h2>Debugging information</h2>")
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req.write("<pre>\n%s\n</pre>\n"%cgi.escape(tb))
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req.write("</body></html>")
added
removed
ivle/dispatch/__init__.py
