From Pascal Quantin:

The decoder expects to do not have any extra byte after the RAR bodies.

But according to 3GPP 36.321 8.8.0 chapter 6.1.5, the eNodeB is allowed to put padding at the end of the RAR PDU:

" A MAC PDU consists of a MAC header and zero or more MAC Random Access Responses (MAC RAR) and optionally padding as described in figure 6.1.5-4.
[...]

Padding may occur after the last MAC RAR. Presence and length of padding is implicit based on TB size, size of MAC header and number of RARs."

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@33783 f5534014-38df-0310-8fa8-9805f1628bb7

diff --git a/epan/dissectors/packet-mac-lte.c b/epan/dissectors/packet-mac-lte.c
index 5d336cad2a6c0b07200cd5891049421d0ce88858..e4ad3006789f25432f8e335880d62542716da1cd 100644 (file)
--- a/epan/dissectors/packet-mac-lte.c
+++ b/epan/dissectors/packet-mac-lte.c
@@ -1194,6 +1194,7 @@ static void dissect_rar(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, pro
     proto_tree *rar_headers_tree;
     proto_item *ti;
     proto_item *rar_headers_ti;
+    proto_item *padding_length_ti;
     int        start_headers_offset = offset;
 
     write_pdu_label_and_info(pdu_ti, NULL, pinfo,
@@ -1312,12 +1313,18 @@ static void dissect_rar(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, pro
     /* Update TAP info */
     tap_info->number_of_rars += number_of_rars;
 
-    /* Warn if we don't seem to have reached the end of the frame yet */
-    if (tvb_length_remaining(tvb, offset) != 0) {
-           expert_add_info_format(pinfo, pdu_ti, PI_MALFORMED, PI_ERROR,
-                                  "%u bytes remaining after RAR PDU dissected",
-                                  tvb_length_remaining(tvb, offset));
+    /* Padding may follow */
+    if (tvb_length_remaining(tvb, offset) > 0) {
+        proto_tree_add_item(tree, hf_mac_lte_padding_data,
+                            tvb, offset, -1, FALSE);
     }
+    padding_length_ti = proto_tree_add_int(tree, hf_mac_lte_padding_length,
+                                           tvb, offset, 0,
+                                           p_mac_lte_info->length - offset);
+    PROTO_ITEM_SET_GENERATED(padding_length_ti);
+
+    /* Update padding bytes in stats */
+    tap_info->padding_bytes += (p_mac_lte_info->length - offset);
 }