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Diffstat (limited to 'websdk/werkzeug/contrib/fixers.py')
| -rw-r--r-- | websdk/werkzeug/contrib/fixers.py | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/websdk/werkzeug/contrib/fixers.py b/websdk/werkzeug/contrib/fixers.py new file mode 100644 index 0000000..6286e6c --- /dev/null +++ b/websdk/werkzeug/contrib/fixers.py @@ -0,0 +1,224 @@ +# -*- coding: utf-8 -*- +""" + werkzeug.contrib.fixers + ~~~~~~~~~~~~~~~~~~~~~~~ + + .. versionadded:: 0.5 + + This module includes various helpers that fix bugs in web servers. They may + be necessary for some versions of a buggy web server but not others. We try + to stay updated with the status of the bugs as good as possible but you have + to make sure whether they fix the problem you encounter. + + If you notice bugs in webservers not fixed in this module consider + contributing a patch. + + :copyright: Copyright 2009 by the Werkzeug Team, see AUTHORS for more details. + :license: BSD, see LICENSE for more details. +""" +from urllib import unquote +from werkzeug.http import parse_options_header, parse_cache_control_header, \ + parse_set_header +from werkzeug.useragents import UserAgent +from werkzeug.datastructures import Headers, ResponseCacheControl + + +class LighttpdCGIRootFix(object): + """Wrap the application in this middleware if you are using lighttpd + with FastCGI or CGI and the application is mounted on the URL root. + + :param app: the WSGI application + """ + + def __init__(self, app): + self.app = app + + def __call__(self, environ, start_response): + # only set PATH_INFO for older versions of Lighty or if no + # server software is provided. That's because the test was + # added in newer Werkzeug versions and we don't want to break + # people's code if they are using this fixer in a test that + # does not set the SERVER_SOFTWARE key. + if 'SERVER_SOFTWARE' not in environ or \ + environ['SERVER_SOFTWARE'] < 'lighttpd/1.4.28': + environ['PATH_INFO'] = environ.get('SCRIPT_NAME', '') + \ + environ.get('PATH_INFO', '') + environ['SCRIPT_NAME'] = '' + return self.app(environ, start_response) + + +class PathInfoFromRequestUriFix(object): + """On windows environment variables are limited to the system charset + which makes it impossible to store the `PATH_INFO` variable in the + environment without loss of information on some systems. + + This is for example a problem for CGI scripts on a Windows Apache. + + This fixer works by recreating the `PATH_INFO` from `REQUEST_URI`, + `REQUEST_URL`, or `UNENCODED_URL` (whatever is available). Thus the + fix can only be applied if the webserver supports either of these + variables. + + :param app: the WSGI application + """ + + def __init__(self, app): + self.app = app + + def __call__(self, environ, start_response): + for key in 'REQUEST_URL', 'REQUEST_URI', 'UNENCODED_URL': + if key not in environ: + continue + request_uri = unquote(environ[key]) + script_name = unquote(environ.get('SCRIPT_NAME', '')) + if request_uri.startswith(script_name): + environ['PATH_INFO'] = request_uri[len(script_name):] \ + .split('?', 1)[0] + break + return self.app(environ, start_response) + + +class ProxyFix(object): + """This middleware can be applied to add HTTP proxy support to an + application that was not designed with HTTP proxies in mind. It + sets `REMOTE_ADDR`, `HTTP_HOST` from `X-Forwarded` headers. + + Do not use this middleware in non-proxy setups for security reasons. + + The original values of `REMOTE_ADDR` and `HTTP_HOST` are stored in + the WSGI environment as `werkzeug.proxy_fix.orig_remote_addr` and + `werkzeug.proxy_fix.orig_http_host`. + + :param app: the WSGI application + """ + + def __init__(self, app): + self.app = app + + def get_remote_addr(self, forwarded_for): + """Selects the new remote addr from the given list of ips in + X-Forwarded-For. By default the first one is picked. + + .. versionadded:: 0.8 + """ + if forwarded_for: + return forwarded_for[0] + + def __call__(self, environ, start_response): + getter = environ.get + forwarded_proto = getter('HTTP_X_FORWARDED_PROTO', '') + forwarded_for = getter('HTTP_X_FORWARDED_FOR', '').split(',') + forwarded_host = getter('HTTP_X_FORWARDED_HOST', '') + environ.update({ + 'werkzeug.proxy_fix.orig_wsgi_url_scheme': getter('wsgi.url_scheme'), + 'werkzeug.proxy_fix.orig_remote_addr': getter('REMOTE_ADDR'), + 'werkzeug.proxy_fix.orig_http_host': getter('HTTP_HOST') + }) + forwarded_for = [x for x in [x.strip() for x in forwarded_for] if x] + remote_addr = self.get_remote_addr(forwarded_for) + if remote_addr is not None: + environ['REMOTE_ADDR'] = remote_addr + if forwarded_host: + environ['HTTP_HOST'] = forwarded_host + if forwarded_proto: + environ['wsgi.url_scheme'] = forwarded_proto + return self.app(environ, start_response) + + +class HeaderRewriterFix(object): + """This middleware can remove response headers and add others. This + is for example useful to remove the `Date` header from responses if you + are using a server that adds that header, no matter if it's present or + not or to add `X-Powered-By` headers:: + + app = HeaderRewriterFix(app, remove_headers=['Date'], + add_headers=[('X-Powered-By', 'WSGI')]) + + :param app: the WSGI application + :param remove_headers: a sequence of header keys that should be + removed. + :param add_headers: a sequence of ``(key, value)`` tuples that should + be added. + """ + + def __init__(self, app, remove_headers=None, add_headers=None): + self.app = app + self.remove_headers = set(x.lower() for x in (remove_headers or ())) + self.add_headers = list(add_headers or ()) + + def __call__(self, environ, start_response): + def rewriting_start_response(status, headers, exc_info=None): + new_headers = [] + for key, value in headers: + if key.lower() not in self.remove_headers: + new_headers.append((key, value)) + new_headers += self.add_headers + return start_response(status, new_headers, exc_info) + return self.app(environ, rewriting_start_response) + + +class InternetExplorerFix(object): + """This middleware fixes a couple of bugs with Microsoft Internet + Explorer. Currently the following fixes are applied: + + - removing of `Vary` headers for unsupported mimetypes which + causes troubles with caching. Can be disabled by passing + ``fix_vary=False`` to the constructor. + see: http://support.microsoft.com/kb/824847/en-us + + - removes offending headers to work around caching bugs in + Internet Explorer if `Content-Disposition` is set. Can be + disabled by passing ``fix_attach=False`` to the constructor. + + If it does not detect affected Internet Explorer versions it won't touch + the request / response. + """ + + # This code was inspired by Django fixers for the same bugs. The + # fix_vary and fix_attach fixers were originally implemented in Django + # by Michael Axiak and is available as part of the Django project: + # http://code.djangoproject.com/ticket/4148 + + def __init__(self, app, fix_vary=True, fix_attach=True): + self.app = app + self.fix_vary = fix_vary + self.fix_attach = fix_attach + + def fix_headers(self, environ, headers, status=None): + if self.fix_vary: + header = headers.get('content-type', '') + mimetype, options = parse_options_header(header) + if mimetype not in ('text/html', 'text/plain', 'text/sgml'): + headers.pop('vary', None) + + if self.fix_attach and 'content-disposition' in headers: + pragma = parse_set_header(headers.get('pragma', '')) + pragma.discard('no-cache') + header = pragma.to_header() + if not header: + headers.pop('pragma', '') + else: + headers['Pragma'] = header + header = headers.get('cache-control', '') + if header: + cc = parse_cache_control_header(header, + cls=ResponseCacheControl) + cc.no_cache = None + cc.no_store = False + header = cc.to_header() + if not header: + headers.pop('cache-control', '') + else: + headers['Cache-Control'] = header + + def run_fixed(self, environ, start_response): + def fixing_start_response(status, headers, exc_info=None): + self.fix_headers(environ, Headers.linked(headers), status) + return start_response(status, headers, exc_info) + return self.app(environ, fixing_start_response) + + def __call__(self, environ, start_response): + ua = UserAgent(environ) + if ua.browser != 'msie': + return self.app(environ, start_response) + return self.run_fixed(environ, start_response) |