Wireshark · Ethereal-dev: [Ethereal-dev] tvbuff questions and conclusions...

[Diwakar Shetty <diwakar@xxxxxxxxxxxxxx>]

hi

In order to transfer the existing code from 0.8.9 to 0.8.16......i went
through the tvbuff.c and tvbuff.h files to understand the working of
tvbuff. This had to be done because personally I found the documentation
about the interfaces to tvbuff (in tvbuff.h) to be not that thorough
which I expected...

so I have come to some conclusions and also some doubths....

please let me know if i am wrong in the conclusions....

Conclusion No. 1: traversal down the tvb tree is done by the "used_in"
field of "struct tvbuff"

Conclusion No. 2: traversal up the tvb tree is done by the "subset"
field of "struct tvbuff"

Doubth No.1  : Why two "len" fields are required (one of which is in
"struct tvbuff" and another in the "subset" field of "struct tvbuff") .
I am asking because both of them are set to the same value in the
function "tvb_set_subset()"

Doubth No. 2 : Why is  "used_in" field of "struct tvbuff" a pointer to a
list. Shouldn't it be just a pointer to "struct tvbuff". I am asking
because upon going through the code , one finds that "used_in" points
just to one entry i.e the "new_subset".

thanks

diwakar