H2: Should there be a limit to tolerance ?

In RFC7540, 5.5 we have:

   Implementations MUST ignore unknown or unsupported values in all
   extensible protocol elements.  Implementations MUST discard frames
   that have unknown or unsupported types.  This means that any of these
   extension points can be safely used by extensions without prior
   arrangement or negotiation.

Such unlimited tolerance for what might be plain garbage seems unwise.

We have covered the trivial case of an endless stream of zero bytes
(DATA on stream=0 is CONN::PROTOCOL_ERROR) but a surprisingly large
percentage of random garbage runs straight through the clause above
and into /dev/null.

Has anybody else implemented limits to patience in this area, and if
so should we try to coordinate our criteria ?

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

Received on Friday, 17 February 2017 09:52:29 UTC