tvbuff_t *
tvb_new_subset_length(tvbuff_t *backing, const gint backing_offset, const gint backing_length)
{
gint captured_length;
tvbuff_t *tvb;
guint subset_tvb_offset;
guint subset_tvb_length;
DISSECTOR_ASSERT(backing && backing->initialized);
THROW_ON(backing_length < 0, ReportedBoundsError);
/*
* Give the next dissector only captured_length bytes.
*/
captured_length = tvb_length_remaining(backing, backing_offset);
THROW_ON(captured_length < 0, BoundsError);
if (captured_length > backing_length)
captured_length = backing_length;
tvb_check_offset_length(backing, backing_offset, captured_length,
&subset_tvb_offset,
&subset_tvb_length);
tvb = tvb_new_with_subset(backing, backing_length,
subset_tvb_offset, subset_tvb_length);
tvb_add_to_chain(backing, tvb);
return tvb;
}
static void
dissect_mime_encap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_item* item;
guint len;
/* XXX, COL_INFO */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MIME_FILE");
item = proto_tree_add_item(tree, proto_mime_encap, tvb, 0, -1, ENC_NA);
/* frames with nsec >= 1000000000 means errors :) */
if (pinfo->fd->abs_ts.nsecs >= 1000000000) {
proto_item_append_text(item, " (Error)");
/* return; */ /* dissect what we have */
}
len = tvb_length(tvb);
if (!pinfo->fd->flags.visited) {
if (len) {
tvbuff_t *cloned_tvb = tvb_clone(tvb);
if (!file_tvbs) {
file_tvbs = cloned_tvb;
whole_tvb = tvb_new_composite();
} else
tvb_add_to_chain(file_tvbs, cloned_tvb);
tvb_composite_append(whole_tvb, cloned_tvb);
} else
tvb_composite_finalize(whole_tvb);
}
/* End of file? */
if (!len && whole_tvb) {
/*
* Here we're doing some trick.
*
* We don't want to call dissectors with composite tvb, cause dissectors can create subsets or real data child
* on it, which would append to whole_tvb chain and would be freed only in mime_encap_init.
*
* So we create some tvb which pass all calls to whole_tvb, but chain with tvb (which is freed in dissection cleanup)
*/
tvbuff_t *tmp_tvb = tvb_new_chain(tvb, whole_tvb);
proto_item_append_text(item, " (Final)");
add_new_data_source(pinfo, tmp_tvb, "Whole file");
if (!dissector_try_heuristic(heur_subdissector_list, tmp_tvb, pinfo, tree, NULL)) {
proto_item_append_text(item, " (Unhandled)");
call_dissector(data_handle, tmp_tvb, pinfo, tree);
}
}
}
tvbuff_t *
tvb_new_subset_remaining(tvbuff_t *backing, const gint backing_offset)
{
tvbuff_t *tvb;
guint subset_tvb_offset;
guint subset_tvb_length;
tvb_check_offset_length(backing, backing_offset, -1 /* backing_length */,
&subset_tvb_offset,
&subset_tvb_length);
tvb = tvb_new_with_subset(backing, -1 /* reported_length */,
subset_tvb_offset, subset_tvb_length);
tvb_add_to_chain(backing, tvb);
return tvb;
}
tvbuff_t *
tvb_new_subset(tvbuff_t *backing, const gint backing_offset, const gint backing_length, const gint reported_length)
{
tvbuff_t *tvb;
guint subset_tvb_offset;
guint subset_tvb_length;
DISSECTOR_ASSERT(backing && backing->initialized);
THROW_ON(reported_length < -1, ReportedBoundsError);
tvb_check_offset_length(backing, backing_offset, backing_length,
&subset_tvb_offset,
&subset_tvb_length);
tvb = tvb_new_with_subset(backing, reported_length,
subset_tvb_offset, subset_tvb_length);
tvb_add_to_chain(backing, tvb);
return tvb;
}
