haven't reassembled, we're probably moving sequentially through the
packet, which means that we'll run past the end of the fragment rather
than past the end of what would have been the reassembled packet had we
reassembled it.
I.e., there's little reason to care whether we're past the end of the
fragment but not past the end of the packet, or whether we're past the
end of the packet; in either case, we're past the end of the fragment,
and if somebody wants to know whether the packet is malformed by
stopping short of certain fields, they should enable reassembly.
So we get rid of the explicit fragment length in tvbuffs and, instead,
have a "this is a fragment" flag; if that flag is set, we throw
FragmentBoundsError rather than ReportedBoundsError if we run past the
end of the reported data.
(This also means we could flag the tvbuff even if we don't know how
large the reassembled packet will be, e.g. when doing IP reassembly.)
Replace tvb_new_subset_length_fragment() with tvb_new_subset_length()
and a new "set the "this is a fragment flag"" routine.
svn path=/trunk/; revision=48940
first fragment of a non-reassembled packet, and we know the length the
packet would have if it were reassembled, this field holds the length of
the fragment, and the "reported length" field shows the length the
packet would have if it were reassembled, so going past the end of the
fragment but staying within the length of the reassembled packet can be
reported as "dissection would have worked if the packet had been
reassembled" rather than "the packet is too short, so it was probably
malformed".
Add a FragmentBoundsError exception, thrown in the "dissection would
have worked if the packet had been reassembled" case.
Add a new tvb_new_subset_length_fragment() routine to create a new
subset tvb with specified fragment and reported lengths. Use it in the
CLNP dissector.
Add some more sanity checks in the CLNP dissector.
svn path=/trunk/; revision=48917
- Essentially no changes from current dissector de facto tvbuff usage;
- Do away with 'usage_counts' and with 'used_in' GSLists;
- Manage tvb chains via a simple doubly linked list.
- API changes:
a. tvb_increment_usage_count() and tvb_decrement_usage_count() no
longer exist;
b. tvb_free_chain() can only be called for the 'top-level' (initial)
tvb of a chain) or for a tvb not in a chain.
c. tvb_free() now just calls tvb_free_chain() [should have no impact
on existing dissectors].
svn path=/trunk/; revision=40264
Guy Harris