| from django.utils.http import http_date |
| |
| class ConditionalGetMiddleware(object): |
| """ |
| Handles conditional GET operations. If the response has a ETag or |
| Last-Modified header, and the request has If-None-Match or |
| If-Modified-Since, the response is replaced by an HttpNotModified. |
| |
| Also sets the Date and Content-Length response-headers. |
| """ |
| def process_response(self, request, response): |
| response['Date'] = http_date() |
| if not response.has_header('Content-Length'): |
| response['Content-Length'] = str(len(response.content)) |
| |
| if response.has_header('ETag'): |
| if_none_match = request.META.get('HTTP_IF_NONE_MATCH', None) |
| if if_none_match == response['ETag']: |
| # Setting the status is enough here. The response handling path |
| # automatically removes content for this status code (in |
| # http.conditional_content_removal()). |
| response.status_code = 304 |
| |
| if response.has_header('Last-Modified'): |
| if_modified_since = request.META.get('HTTP_IF_MODIFIED_SINCE', None) |
| if if_modified_since == response['Last-Modified']: |
| # Setting the status code is enough here (same reasons as |
| # above). |
| response.status_code = 304 |
| |
| return response |
| |
| class SetRemoteAddrFromForwardedFor(object): |
| """ |
| Middleware that sets REMOTE_ADDR based on HTTP_X_FORWARDED_FOR, if the |
| latter is set. This is useful if you're sitting behind a reverse proxy that |
| causes each request's REMOTE_ADDR to be set to 127.0.0.1. |
| |
| Note that this does NOT validate HTTP_X_FORWARDED_FOR. If you're not behind |
| a reverse proxy that sets HTTP_X_FORWARDED_FOR automatically, do not use |
| this middleware. Anybody can spoof the value of HTTP_X_FORWARDED_FOR, and |
| because this sets REMOTE_ADDR based on HTTP_X_FORWARDED_FOR, that means |
| anybody can "fake" their IP address. Only use this when you can absolutely |
| trust the value of HTTP_X_FORWARDED_FOR. |
| """ |
| def process_request(self, request): |
| try: |
| real_ip = request.META['HTTP_X_FORWARDED_FOR'] |
| except KeyError: |
| return None |
| else: |
| # HTTP_X_FORWARDED_FOR can be a comma-separated list of IPs. The |
| # client's IP will be the first one. |
| real_ip = real_ip.split(",")[0].strip() |
| request.META['REMOTE_ADDR'] = real_ip |