handling bad priority parameters

Matthew Kerwin <matthew@kerwin.net.au> Fri, 22 August 2014 03:34 UTC

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From: Matthew Kerwin <matthew@kerwin.net.au>
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Subject: handling bad priority parameters
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I'm currently working through stream prioritisation in draft-14, and I have
two questions. Sorry if they've been discussed already, I searched the
mailing list archives but couldn't find anything (at least back to around
the draft-10 era).

1. What's the appropriate reaction if a HEADERS or PRIORITY frame includes
an invalid stream dependency? i.e. too large, odd when it should be even,
etc? I can see a case for allowing future IDs into the tree, completely
ignoring bad priority data, or for throwing a stream error. Which should it
be?

​2. What do we do if we receive a trailing HEADERS ​frame that contains
priority info? §5.3 says: "A client can assign a priority for a new stream
by including prioritization information in the HEADERS frame that opens the
stream.  For an existing stream, the PRIORITY frame can be used to change
the priority." But nothing explicitly says what to do if the HEADERS frame
with the priority info isn't the HEADERS frame that opens the stream. I
would appreciate a bit of text either there or in §6.2 that clarifies the
point.

Cheers
-- 
  Matthew Kerwin
  http://matthew.kerwin.net.au/