In "fragment_add_seq_check()", handle short frames the same way

regardless of whether they're the first frame we see in a reassembly or
not - put all but the last fragment into the hash table (so subsequent
frames with the same reassembly ID don't get misdissected as
unfragmented frames), return the head of the fragment list for the first
fragment and NULL for all other fragments (so the first fragment gets
dissected as a fragmented packet), and unhash the fragment head from the
reassembly hash table when we see the last fragment.

svn path=/trunk/; revision=5189

1 files changed, 24 insertions, 49 deletions

diff --git a/reassemble.c b/reassemble.c
index ba2900cc95..7683a4df3f 100644
--- a/reassemble.c
+++ b/reassemble.c
@@ -1,7 +1,7 @@
 /* reassemble.c
  * Routines for {fragment,segment} reassembly
  *
- * $Id: reassemble.c,v 1.14 2002/04/17 10:07:57 guy Exp $
+ * $Id: reassemble.c,v 1.15 2002/04/17 10:59:58 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -1016,35 +1016,6 @@ fragment_add_seq_check(tvbuff_t *tvb, int offset, packet_info *pinfo,
 			return fd_head;
 		}
 
-		if (short_frame) {
-			/*
-			 * This is a short frame, so don't do
-			 * reassembly on it.  (We had to be called
-			 * even on short frames, so that we can
-			 * check for fragments that are both the
-			 * first and last fragment, and handle
-			 * them as unfragmented packets.)
-			 *
-			 * If it's the first frame (fragment number
-			 * is 0), handle it as an unfragmented
-			 * packet.
-			 *
-			 * If it's not the first frame, enter it
-			 * into the hash table, but *don't* do
-			 * any further reassembly work on it;
-			 * it'll just sit there in the hash table
-			 * as an indication that we started a
-			 * reassembly, so that when we see the
-			 * last fragment, we don't get confused and
-			 * think it's an unfragmented packet.
-			 */
-			if (frag_number == 0) {
-				fragment_reassembled(fd_head, pinfo,
-				       reassembled_table);
-				return fd_head;
-			}
-		}
-
 		/*
 		 * We're going to use the key to insert the fragment,
 		 * so allocate a structure for it, and copy the
@@ -1057,32 +1028,36 @@ fragment_add_seq_check(tvbuff_t *tvb, int offset, packet_info *pinfo,
 		new_key->id = key.id;
 		g_hash_table_insert(fragment_table, new_key, fd_head);
 
-		if (short_frame)
-			return NULL;
-
-		orig_key = NULL;	/* paranoia */
+		orig_key = new_key;	/* for unhashing it later */
 	} else {
 		/*
 		 * We found it.
 		 */
 		fd_head = value;
+	}
 
-		/*
-		 * If this is a short frame, then we can't, and don't,
-		 * do reassembly on it.  We just return NULL so
-		 * that it's shown as a fragment.
-		 *
-		 * However, if "more_frags" isn't set, we get rid of
-		 * the entry in the hash table for this reassembly,
-		 * as we don't need it any more.
-		 */
-		if (short_frame) {
-			if (!more_frags) {
-				old_key = orig_key;
-				fragment_unhash(fragment_table, old_key);
-			}
-			return NULL;
+	/*
+	 * If this is a short frame, then we can't, and don't, do
+	 * reassembly on it.
+	 *
+	 * If it's the first frame (fragment number is 0), handle it
+	 * as an unfragmented packet.  Otherwise, just handle it
+	 * as a fragment.
+	 *
+	 * If "more_frags" isn't set, we get rid of the entry in the
+	 * hash table for this reassembly, as we don't need it any more.
+	 */
+	if (short_frame) {
+		if (!more_frags) {
+			/*
+			 * Remove this from the table of in-progress
+			 * reassemblies, and free up any memory used for
+			 * it in that table.
+			 */
+			old_key = orig_key;
+			fragment_unhash(fragment_table, old_key);
 		}
+		return frag_number == 0 ? fd_head : NULL;
 	}
 
 	if (fragment_add_seq_work(fd_head, tvb, offset, pinfo, id,