JIRA issue TS-4698 and pull request https://github.com/apache/trafficserver/pull/822 propose to add a TS API function to determine whether the current client request represents a websocket connection attempt.
The motivation: I’ve been working on a C++ API intercept plugin which, among other things, is able to terminate websocket connections. I thought it might be of interest to contribute a websocket termination example (see TS-4699 and the associated pull request https://github.com/apache/trafficserver/pull/824). In order for such a plugin to determine whether the incoming connection is a websocket connection it seems appropriate that * it use the same test that TS already uses internally to make this decision, and that * the ‘official correct way’ to make this decision be exposed through an API function. For this purpose I’m proposing to add a function called TSHttpTxnIsWebsocket. It takes a TSHttpTxn and returns a C int, to be interpreted as a bool in the standard C way, namely non-zero means true. The test checks whether the HttpSM state is_upgrade_request flag is set with an upgrade_token_wks of MIME_VALUE_WEBSOCKET. IIUC this is equivalent to the incoming request having an upgrade header with a value of `websocket`. Documentation for this very simple function is in TSHttpTxnIsWebsocket.en.rst in the PR. Cheers, Oliver
