Wireshark · Wireshark-dev: Re: [Wireshark-dev] tvb_reported_length() vs tvb_length()

[Bill Meier <wmeier@xxxxxxxxxxx>]

Jeff Morriss wrote:
> After having made many a comment (on new dissectors) about using the 
> wrong function, I start to wonder:
>
> Should we rename tvb_length() to, say, tvb_captured_length() and 
> tvb_reported_length() to tvb_length()?
>
> Looking at it from the point of the TVB API it doesn't make much sense, 
> but since [it appears that] many dissector writers tend to not think of 
> snapshot lengths when dealing with TVBs, it might be the best way to 
> prevent this problem going forward.

Or maybe just rename tvb_length() to tvb_captured_length() ?

Actually: I guess I should take a step back ?

I see that there are over 400 dissectors which use tvb_length... (> 2400 
usages).

What are the cases where the use of tvb_length... in a dissctors is valid ?

Looking at README.developer in detrail I see that:

1. tvb_length is shown as being used before doing a heuristics check in
   new-style (and presumably heuristics) dissectors.
   In fact: I now see that the return is shown as
   tvb_length not tvb_reported_length.
   (Given this, I made an incorrect commit in a recent commit).

2. When calling tvb_new-subset.

Others ?

Bill