Guy Harris wrote:
On Sep 24, 2009, at 1:08 PM, Bill Meier wrote:
What are the cases where the use of tvb_length... in a dissctors is
valid ?
Off the top of my head, I'd say it's valid if:
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).
...you're doing a check of some sort before you start dissecting, such
as a heuristic dissector test, and you need to know how much data is
actually available so you don't throw an exception and abort the
dissection or...
Schwoo, Bill's email had me worrying that what I put in README.developer
wasn't right (I think I copied the behavior from some new-style
dissector without putting a lot of thought into it). I'll see about
adding some words to the effect of "please be careful not to throw an
exception while doing these heuristics."
