Design Issue: Overlong Frames

[James M Snell <[e-mail]>]

In going through a number of issues relating to frame sizes, I note
that the spec currently does not deal with the issue of "overlong" or
padded frames. That is, what happens if a frame contains more data
than what is explicitly called for in it's definition.

For instance, the GOAWAY frame currently defines it's payload as a
32-bit error code. What happens if that frame contains more than
32-bits? .. e.g.

  00 40 07 00 00 00 00 00
  0A BC DE FF FF FF FF FF

An implementation that is not being careful could completely miss the
extra junk bytes here. For GOAWAY it's obviously not too much of a
concern, but the risk for abuse exists for all frames that define a
specific structure for the payload data.

Recommendation: Adding a short statement that a PROTOCOL_ERROR MUST be
returned if a frame contains more bytes than what is expressly
specified in the frame definition.

- James