- From: Alan Egerton <eggyal@gmail.com>
- Date: Tue, 22 Sep 2020 21:42:17 +0100
- To: Lucas Pardue <lucaspardue.24.7@gmail.com>
- Cc: HTTP Working Group <ietf-http-wg@w3.org>
- Message-ID: <CA+phaec3g5YdyY29OAjSg4QXh62EPRsf3FpdQ09DLU+Ufytb3A@mail.gmail.com>
Hi Lucas, The situations I've described are absolutely illegal PUSH_PROMISE frames—but sections 5.1 and 6.6 appear to disagree over what error handling is appropriate in those situations. -- Alan On Tue, Sep 22, 2020 at 9:09 PM Lucas Pardue <lucaspardue.24.7@gmail.com> wrote: > > > On Tue, Sep 22, 2020 at 8:38 PM Alan Egerton <eggyal@gmail.com> wrote: > >> Thanks Lucas, but I don't think either of those reports are quite the >> same: they both appear to concern the state transition from "idle" state on >> sending a PUSH_PROMISE (and that the spec can be misread as describing >> transitions from that state on receiving such frames); whereas I am >> concerned with the correct error handling on receiving an erroneous >> PUSH_PROMISE in the "half-closed(remote)" or "closed" states. >> >> -- Alan >> >> > oops I meant to say "possibly related" because this is about the handling > of push promises with respect to stream lifecycle. My 2c: > > I might be squinting at the state machine wrong but I don't think it is > practically possible for the client to have a request stream in a > half-closed (remote) and receive a PUSH_PROMISE. Because the only way to > get a stream in that state is for a server to respond to a request with > END_STREAM set, before the client has sent END_STREAM or RST_STREAM. This > is an early response, which is allowed. But the server shouldn't be trying > to promise things after it closed the stream, that's a plain error. > Similarly, a server sending PUSH_PROMISE after RST_STREAM is also an error. > > The odd case is when a client and server have a race about the stream > being closed due to the client sending RST_STREAM in the open state. > "Closed because I said so" is a bit different to "Closed because you said > so". The statement in 6.6 about "MUST handle PUSH_PROMISES" is trying to > wiggle out of the race condition. > > Cheers > Lucas >
Received on Tuesday, 22 September 2020 20:42:41 UTC