Use the reported length, not the captured length, as the fragment length

when doing reassembly.

In some additional places, use "tvb_bytes_exist()" to check whether we
have enough data to do reassembly, rather than checking to see if the
frame is short (it might be short but we might still have enough data to
do reassembly).

In DCE RPC, use the fragment length from the header as the number of
bytes of fragment data.

There's no need to check "pinfo->fragmented" before doing reassembly in
the DCERPC-over-SMB-pipes code - either we have all the data or we
don't.

In SNA and WTP reassembly, add a check to make sure we have all the data
to be reassembled.


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@7282 f5534014-38df-0310-8fa8-9805f1628bb7

1 files changed, 33 insertions, 27 deletions

diff --git a/packet-sna.c b/packet-sna.c
index 06d463c6b1..1fc5f6c729 100644
--- a/packet-sna.c
+++ b/packet-sna.c
@@ -3,7 +3,7 @@
  * Gilbert Ramirez <gram@alumni.rice.edu>
  * Jochen Friedrich <jochen@scram.de>
  *
- * $Id: packet-sna.c,v 1.45 2003/03/02 21:47:45 guy Exp $
+ * $Id: packet-sna.c,v 1.46 2003/03/05 07:17:50 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -1681,6 +1681,7 @@ defragment_by_sequence(packet_info *pinfo, tvbuff_t *tvb, int offset, int mpf,
 	int frag_number = -1;
 	int more_frags = TRUE;
 	tvbuff_t *rh_tvb = NULL;
+	gint frag_len;
 
 	/* Determine frag_number and more_frags */
 	switch(mpf) {
@@ -1703,34 +1704,39 @@ defragment_by_sequence(packet_info *pinfo, tvbuff_t *tvb, int offset, int mpf,
 
 	/* If sna_defragment is on, and this is a fragment.. */
 	if (frag_number > -1) {
-
 		/* XXX - check length ??? */
-		fd_head = fragment_add_seq(tvb, offset, pinfo, id,
-		    sna_fragment_table, frag_number,
-		    tvb_length_remaining(tvb, offset), more_frags);
-
-	/* We added the LAST segment and reassembly didn't complete. Insert
-	 * a zero-length MIDDLE segment to turn a 2-frame BIU-fragmentation
-         * into a 3-frame BIU-fragmentation (empty middle frag).
-         * See above long comment about this trickery. */
-
-		if (mpf == MPF_LAST_SEGMENT && !fd_head) {
+		frag_len = tvb_reported_length_remaining(tvb, offset);
+		if (tvb_bytes_exist(tvb, offset, frag_len)) {
 			fd_head = fragment_add_seq(tvb, offset, pinfo, id,
-			    sna_fragment_table, MIDDLE_FRAG_NUMBER, 0, TRUE);
-		}
-
-		if (fd_head != NULL) {
-			/* We have the complete reassembled payload. */
-			rh_tvb = tvb_new_real_data(fd_head->data,
-			    fd_head->len, fd_head->len);
-
-			/* Add the tvbuff to the chain of tvbuffs so that
-			 * it will get cleaned up too. */
-			tvb_set_child_real_data_tvbuff(tvb, rh_tvb);
-
-			/* Add the defragmented data to the data source list. */
-			add_new_data_source(pinfo, rh_tvb,
-			    "Reassembled SNA BIU");
+			    sna_fragment_table, frag_number, frag_len,
+			    more_frags);
+
+			/* We added the LAST segment and reassembly didn't
+			 * complete. Insert a zero-length MIDDLE segment to
+			 * turn a 2-frame BIU-fragmentation into a 3-frame
+			 * BIU-fragmentation (empty middle frag).
+		         * See above long comment about this trickery. */
+
+			if (mpf == MPF_LAST_SEGMENT && !fd_head) {
+				fd_head = fragment_add_seq(tvb, offset, pinfo,
+				    id, sna_fragment_table,
+				    MIDDLE_FRAG_NUMBER, 0, TRUE);
+			}
+
+			if (fd_head != NULL) {
+				/* We have the complete reassembled payload. */
+				rh_tvb = tvb_new_real_data(fd_head->data,
+				    fd_head->len, fd_head->len);
+
+				/* Add the tvbuff to the chain of tvbuffs
+				 * so that it will get cleaned up too. */
+				tvb_set_child_real_data_tvbuff(tvb, rh_tvb);
+
+				/* Add the defragmented data to the data
+				 * source list. */
+				add_new_data_source(pinfo, rh_tvb,
+				    "Reassembled SNA BIU");
+			}
 		}
 	}
 	return rh_tvb;