Wireshark-dev: Re: [Wireshark-dev] Undissected reserved fields
From: Guy Harris <[email protected]>
Date: Fri, 27 Feb 2015 13:06:04 -0800
On Feb 27, 2015, at 10:28 AM, Jeff Morriss <[email protected]> wrote:

> My opinion (which I've voiced on this list many times over the past ~10 years) is that such fields SHOULD be dissected.  Even better they should have an Expert Info if they are supposed to be 0 and aren't (Guy had suggested on a bug or somewhere that we should have an API with a name that includes "mbz"--for Must Be Zero--which would add the Expert Info automatically).

It was in the thread that started here:

	https://www.wireshark.org/lists/wireshark-dev/201402/msg00131.html

and I suggested both proto_tree_add_spare() (for fields that are spare and *not* required to be zero) and proto_tree_add_mbz() (for fields that *are* required to be zero) in

	https://www.wireshark.org/lists/wireshark-dev/201402/msg00135.html

Neither of those take an hf_ value as an argument, so they don't clutter the list of filterable fields with a bunch of individual values for each set of spare bits; to look for "must be zero but isn't", you'd look for the expert info.