# -*- coding: utf-8 -*- # (c) 2009-2020 Martin Wendt and contributors; see WsgiDAV https://github.com/mar10/wsgidav # Original PyFileServer (c) 2005 Ho Chun Wei. # Licensed under the MIT license: # http://www.opensource.org/licenses/mit-license.php """ WSGI middleware that finds the registered mapped DAV-Provider, creates a new RequestServer instance, and dispatches the request. .. warning:: The following documentation was taken over from PyFileServer and is outdated. WsgiDAV file sharing -------------------- WsgiDAV allows the user to specify in wsgidav.conf a number of realms, and a number of users for each realm. Realms Each realm corresponds to a filestructure on disk to be stored, for example:: addShare('pubshare','/home/public/share') would allow the users to access using WebDAV the directory/file structure at /home/public/share from the url http:////pubshare The realm name is set as '/pubshare' e.g. /home/public/share/WsgiDAV/LICENSE becomes accessible as http:////pubshare/WsgiDAV/LICENSE Users A number of user_name/password pairs can be set for each realm:: adduser('pubshare', 'user_name', 'password', 'description/unused') would add a user_name/password pair to realm /pubshare. Note: if developers wish to maintain a separate users database, you can write your own domain controller for the HTTPAuthenticator. See http_authenticator.py and domain_controller.py for more details. Request Resolver ---------------- WSGI middleware for resolving Realm and Paths for the WsgiDAV application. Usage:: It *must* be configured as the last item on `middleware_stack` list. from wsgidav.request_resolver import RequestResolver config = { ..., 'middleware_stack': [ ..., RequestResolver, ], } The RequestResolver resolves the requested URL to the following values placed in the environ dictionary. First it resolves the corresponding realm:: url: http:////pubshare/WsgiDAV/LICENSE environ['wsgidav.mappedrealm'] = /pubshare Based on the configuration given, the resource abstraction layer for the realm is determined. if no configured abstraction layer is found, the default abstraction layer fileabstractionlayer.FilesystemAbstractionLayer() is used:: environ['wsgidav.resourceAL'] = fileabstractionlayer.MyOwnFilesystemAbstractionLayer() The path identifiers for the requested url are then resolved using the resource abstraction layer:: environ['wsgidav.mappedpath'] = /home/public/share/WsgiDAV/LICENSE environ['wsgidav.mappedURI'] = /pubshare/WsgiDAV/LICENSE in this case, FilesystemAbstractionLayer resolves any relative paths to its canonical absolute path The RequestResolver also resolves any value in the Destination request header, if present, to:: Destination: http:////pubshare/WsgiDAV/LICENSE-dest environ['wsgidav.destrealm'] = /pubshare environ['wsgidav.destpath'] = /home/public/share/WsgiDAV/LICENSE-dest environ['wsgidav.destURI'] = /pubshare/WsgiDAV/LICENSE environ['wsgidav.destresourceAL'] = fileabstractionlayer.MyOwnFilesystemAbstractionLayer() """ from wsgidav import util from wsgidav.dav_error import DAVError, HTTP_NOT_FOUND from wsgidav.middleware import BaseMiddleware from wsgidav.request_server import RequestServer __docformat__ = "reStructuredText" # NOTE (Martin Wendt, 2009-05): # The following remarks were made by Ian Bicking when reviewing PyFileServer in 2005. # I leave them here after my refactoring for reference. # # Remarks: # @@: If this were just generalized URL mapping, you'd map it like: # Incoming: # SCRIPT_NAME=; PATH_INFO=/pubshare/PyFileServer/LICENSE # After transforamtion: # SCRIPT_NAME=/pubshare; PATH_INFO=/PyFileServer/LICENSE # Then you dispatch to the application that serves '/home/public/share/' # # This uses SCRIPT_NAME and PATH_INFO exactly how they are intended to be # used -- they give context about where you are (SCRIPT_NAME) and what you # still have to handle (PATH_INFO) # # An example of an dispatcher that does this is paste.urlmap, and you use it # like: # # urlmap = paste.urlmap.URLMap() # # urlmap is a WSGI application # urlmap['/pubshare'] = PyFileServerForPath('/home/public/share') # # Now, that requires that you have a server that is easily # instantiated, but that's kind of a separate concern -- what you # really want is to do more general configuration at another level. E.g., # you might have:: # # app = config(urlmap, config_file) # # Which adds the configuration from that file to the request, and # PyFileServerForPath then fetches that configuration. paste.deploy # has another way of doing that at instantiation-time; either way # though you want to inherit configuration you can still use more general # dispatching. # # Incidentally some WebDAV servers do redirection based on the user # agent (Zope most notably). This is because of how WebDAV reuses # GET in an obnxious way, so that if you want to use WebDAV on pages # that also include dynamic content you have to mount the whole # thing at another point in the URL space, so you can GET the # content without rendering the dynamic parts. I don't actually # like using user agents -- I'd rather mount the same resources at # two different URLs -- but it's just an example of another kind of # dispatching that can be done at a higher level. # # ======================================================================== # RequestResolver # ======================================================================== class RequestResolver(BaseMiddleware): def __init__(self, wsgidav_app, next_app, config): super(RequestResolver, self).__init__(wsgidav_app, next_app, config) def __call__(self, environ, start_response): path = environ["PATH_INFO"] # We want to answer OPTIONS(*), even if no handler was registered for # the top-level realm (e.g. required to map drive letters). provider = environ["wsgidav.provider"] # Hotfix for WinXP / Vista: accept '/' for a '*' if environ["REQUEST_METHOD"] == "OPTIONS" and path in ("/", "*"): # Answer HTTP 'OPTIONS' method on server-level. # From RFC 2616: # If the Request-URI is an asterisk ("*"), the OPTIONS request is # intended to apply to the server in general rather than to a specific # resource. Since a server's communication options typically depend on # the resource, the "*" request is only useful as a "ping" or "no-op" # type of method; it does nothing beyond allowing the client to test the # capabilities of the server. For example, this can be used to test a # proxy for HTTP/1.1 compliance (or lack thereof). dav_compliance_level = "1,2" if ( provider is None or provider.is_readonly() or provider.lock_manager is None ): dav_compliance_level = "1" headers = [ ("Content-Type", "text/html"), ("Content-Length", "0"), ("DAV", dav_compliance_level), ("Date", util.get_rfc1123_time()), ] if environ["wsgidav.config"].get("add_header_MS_Author_Via", False): headers.append(("MS-Author-Via", "DAV")) start_response("200 OK", headers) yield b"" return if provider is None: raise DAVError( HTTP_NOT_FOUND, "Could not find resource provider for '{}'".format(path) ) # Let the appropriate resource provider for the realm handle the # request app = RequestServer(provider) app_iter = app(environ, start_response) for v in app_iter: yield v if hasattr(app_iter, "close"): app_iter.close() return