Re: PRIORITY stream error?

[Kazuho Oku <[e-mail]>]

2019年3月7日(木) 7:43 Martin Thomson <[e-mail]>:
>
> This view (that the error is localized) is one that we took in HTTP/2.  In retrospect, I don't think that it has been used as much as you would think.  It is far easier to treat violations of spec brutally.  Indeed, this tends to make the problem more visible, which is a good thing.

I'm fine with changing the approach.

The other issue with using RST_STREAM in response to misbehaving peers
is that the frame does (did) not provide  a way to signal what has
actually been wrong. It has stream_id field, but does not have a
reason_phrase.

I'm supportive to handling all the misbehaviors as connection-level
errors in H3, using RESET_STREAM purely for communicating abrupt
termination of the request.

>
> On Thu, Mar 7, 2019, at 09:37, Kazuho Oku wrote:
> > 2019年3月7日(木) 5:59 Martin Duke <[e-mail]>:
> > >
> > > the very end of Section 4.2.3 of quic-http says:
> > >
> > >    PRIORITY frames received by a client MUST be treated as a stream
> > >    error of type HTTP_UNEXPECTED_FRAME.
> > >
> > >
> > > Elsewhere, this kind of thing is a connection error.
> >
> > I am not sure if I agree with the observation. IIUC, the general
> > approach is to use stream errors when the error does not affect the
> > entire connection.
> >
> > It is reasonable for a client to respond with a stream error when it
> > observes a PRIORITY frame on a *request* stream.
> >
> > That said, I agree that it should be a connection error when the
> > client receives a PRIORITY frame on a control frame. That's because we
> > cannot have a stream-level error for a control stream, because the
> > stream can never be closed. I think that's what is missing in the
> > text.
> >
> > FWIW, we do have this "if the error is X then it's a stream-level
> > error, or if the error is Y then it's a connection-level error" type
> > of handling. See section 3.2.2 for an example.
> >
> > > Making this a  stream error seems problematic; if otherwise valid, if this goes out on the control stream a stream error may bring everything down anyway?
> > >
> > > Should this be a connection error, or am I missing something?
> >
> >
> >
> > --
> > Kazuho Oku
> >
> >
>


-- 
Kazuho Oku