Ported fixes and improvements from Wireshark for RLC/MAC control block decoding. Part 1.

Generic improvements to the csn.1 dissector include:
• Added a flag to the type descriptor structure so that any type can (potentially) flagged as xxx_OR_NULL.  This was specifically needed for UINT_OR_NULL for the ms capabilities struct.
• Changed the CSN_SERIALIZE so that the length of the length field can be specified.
• For CSN_NEXT_EXIST removed the requirement that the next type be CSN_END, to allow truncation of multiple IEs.
• For CSN_LEFT_ALIGNED_VAR_BITMAP corrected the handling of bit_offset.
• Added a new type CSN_PADDING_BITS to make inspection of padding bits more convenient.
• Improved the CSN_RECURSIVE_TARRAY_1 to show the array index.

Improvements to the gsm_rlcmac dissector include:
• Rework the definition of EGPRS Ack/Nack Description so that the length IE (and absence thereof) is handled correctly.
• Added Padding Bits definitions to all PDUs
• Change the Multislot_capability_t and Content_t definitions to allow truncation at any IE

1 files changed, 135 insertions, 57 deletions

diff --git a/src/gsm_rlcmac.cpp b/src/gsm_rlcmac.cpp
index e4afd7b9..a39a5c06 100644
--- a/src/gsm_rlcmac.cpp
+++ b/src/gsm_rlcmac.cpp
@@ -166,22 +166,47 @@ CSN_DESCR_BEGIN(Channel_Quality_Report_t)
   M_UINT       (Channel_Quality_Report_t,  Slot[7].I_LEVEL_TN,  4),
 CSN_DESCR_END  (Channel_Quality_Report_t)
 
-/*< EGPRS Ack/Nack Description >*/
+/*< EGPRS Ack/Nack Description struct >*/
 static const
-CSN_DESCR_BEGIN   (EGPRS_AckNack_t)
-  M_NEXT_EXIST    (EGPRS_AckNack_t, Exist_LENGTH, 1),
-  M_UINT          (EGPRS_AckNack_t,  LENGTH,  8),
+CSN_DESCR_BEGIN   (EGPRS_AckNack_Desc_t)
+  M_UINT          (EGPRS_AckNack_Desc_t,  FINAL_ACK_INDICATION,  1),
+  M_UINT          (EGPRS_AckNack_Desc_t,  BEGINNING_OF_WINDOW,  1),
+  M_UINT          (EGPRS_AckNack_Desc_t,  END_OF_WINDOW,  1),
+  M_UINT          (EGPRS_AckNack_Desc_t,  STARTING_SEQUENCE_NUMBER,  11),
 
-  M_UINT          (EGPRS_AckNack_t,  FINAL_ACK_INDICATION,  1),
-  M_UINT          (EGPRS_AckNack_t,  BEGINNING_OF_WINDOW,  1),
-  M_UINT          (EGPRS_AckNack_t,  END_OF_WINDOW,  1),
-  M_UINT          (EGPRS_AckNack_t,  STARTING_SEQUENCE_NUMBER,  11),
+  M_NEXT_EXIST    (EGPRS_AckNack_Desc_t,  Exist_CRBB, 3),
+  M_UINT          (EGPRS_AckNack_Desc_t,  CRBB_LENGTH,  7),
+  M_UINT          (EGPRS_AckNack_Desc_t,  CRBB_STARTING_COLOR_CODE,  1),
+  M_LEFT_VAR_BMP  (EGPRS_AckNack_Desc_t,  CRBB, CRBB_LENGTH, 0),
 
-  M_NEXT_EXIST    (EGPRS_AckNack_t, Exist_CRBB, 3),
-  M_UINT          (EGPRS_AckNack_t,  CRBB_LENGTH,  7),
-  M_UINT          (EGPRS_AckNack_t,  CRBB_STARTING_COLOR_CODE,  1),
-  M_LEFT_VAR_BMP  (EGPRS_AckNack_t, CRBB, CRBB_LENGTH, 0),
-CSN_DESCR_END     (EGPRS_AckNack_t)
+  M_LEFT_VAR_BMP_1(EGPRS_AckNack_Desc_t,  URBB, URBB_LENGTH, 0),
+CSN_DESCR_END     (EGPRS_AckNack_Desc_t)
+
+/*< EGPRS Ack/Nack Description IE >*/
+gint16 Egprs_Ack_Nack_Desc_w_len_Dissector(csnStream_t* ar, bitvec *vector, unsigned& readIndex, void* data)
+{
+  if (ar->direction == 0)
+  {
+    return csnStreamEncoder(ar, CSNDESCR(EGPRS_AckNack_Desc_t), vector, readIndex, data);
+  }
+  else
+  {
+    return csnStreamDecoder(ar, CSNDESCR(EGPRS_AckNack_Desc_t), vector, readIndex, data);
+  }
+}
+
+/* this intermediate structure is only required because M_SERIALIZE cannot be used as a member of M_UNION */
+static const
+CSN_DESCR_BEGIN(EGPRS_AckNack_w_len_t)
+  M_SERIALIZE  (EGPRS_AckNack_w_len_t, Desc, 8, Egprs_Ack_Nack_Desc_w_len_Dissector),
+CSN_DESCR_END  (EGPRS_AckNack_w_len_t)
+
+static const
+CSN_DESCR_BEGIN(EGPRS_AckNack_t)
+  M_UNION      (EGPRS_AckNack_t,  2),
+  M_TYPE       (EGPRS_AckNack_t, Desc, EGPRS_AckNack_Desc_t),
+  M_TYPE       (EGPRS_AckNack_t, Desc, EGPRS_AckNack_w_len_t),
+CSN_DESCR_END  (EGPRS_AckNack_t)
 
 /*<P1 Rest Octets>*/
 /*<P2 Rest Octets>*/
@@ -517,6 +542,7 @@ CSN_DESCR_BEGIN(Packet_Polling_Request_t)
   M_UINT       (Packet_Polling_Request_t,  PAGE_MODE,  2),
   M_TYPE       (Packet_Polling_Request_t, ID, PacketPollingID_t),
   M_BIT        (Packet_Polling_Request_t,  TYPE_OF_ACK),
+  M_PADDING_BITS(Packet_Polling_Request_t),
 CSN_DESCR_END  (Packet_Polling_Request_t)
 
 static const
@@ -652,6 +678,7 @@ CSN_DESCR_BEGIN(Packet_TBF_Release_t)
   M_BIT        (Packet_TBF_Release_t,  UPLINK_RELEASE),
   M_BIT        (Packet_TBF_Release_t,  DOWNLINK_RELEASE),
   M_UINT       (Packet_TBF_Release_t,  TBF_RELEASE_CAUSE,  4),
+  M_PADDING_BITS(Packet_TBF_Release_t ),
 CSN_DESCR_END  (Packet_TBF_Release_t)
 
 /*< Packet Control Acknowledgement message content >*/
@@ -684,6 +711,7 @@ CSN_DESCR_BEGIN        (Packet_Control_Acknowledgement_t)
   M_UINT               (Packet_Control_Acknowledgement_t,  CTRL_ACK,  2),
   M_NEXT_EXIST_OR_NULL (Packet_Control_Acknowledgement_t, Exist_AdditionsR5, 1),
   M_TYPE               (Packet_Control_Acknowledgement_t, AdditionsR5, Packet_Control_Acknowledgement_AdditionsR5_t),
+  M_PADDING_BITS       (Packet_Control_Acknowledgement_t),
 CSN_DESCR_END  (Packet_Control_Acknowledgement_t)
 
 /*< Packet Downlink Dummy Control Block message content >*/
@@ -694,6 +722,7 @@ CSN_DESCR_BEGIN(Packet_Downlink_Dummy_Control_Block_t)
 
   M_NEXT_EXIST (Packet_Downlink_Dummy_Control_Block_t, Exist_PERSISTENCE_LEVEL, 1),
   M_UINT_ARRAY (Packet_Downlink_Dummy_Control_Block_t, PERSISTENCE_LEVEL, 4, 4),
+  M_PADDING_BITS(Packet_Downlink_Dummy_Control_Block_t ),
 CSN_DESCR_END  (Packet_Downlink_Dummy_Control_Block_t)
 
 /*< Packet Uplink Dummy Control Block message content >*/
@@ -706,6 +735,7 @@ CSN_DESCR_BEGIN(Packet_Uplink_Dummy_Control_Block_t)
   M_UINT       (Packet_Uplink_Dummy_Control_Block_t,  MESSAGE_TYPE,  6),
   M_UINT       (Packet_Uplink_Dummy_Control_Block_t,  TLLI,  32),
 /*M_FIXED      (Packet_Uplink_Dummy_Control_Block_t, 1, 0),*/
+  M_PADDING_BITS(Packet_Uplink_Dummy_Control_Block_t),
 CSN_DESCR_END  (Packet_Uplink_Dummy_Control_Block_t)
 
 static const
@@ -728,7 +758,7 @@ gint16 Receive_N_PDU_Number_list_Dissector(csnStream_t* ar, bitvec *vector, unsi
 
 static const
 CSN_DESCR_BEGIN(Receive_N_PDU_Number_list_t)
-  M_SERIALIZE  (Receive_N_PDU_Number_list_t, IEI, Receive_N_PDU_Number_list_Dissector),
+  M_SERIALIZE  (Receive_N_PDU_Number_list_t, IEI, 7, Receive_N_PDU_Number_list_Dissector),
   M_VAR_TARRAY (Receive_N_PDU_Number_list_t, Receive_N_PDU_Number, Receive_N_PDU_Number_t, Count_Receive_N_PDU_Number),
 CSN_DESCR_END  (Receive_N_PDU_Number_list_t)
 
@@ -747,25 +777,25 @@ CSN_DESCR_END         (DTM_EGPRS_HighMultislotClass_t)
 
 static const
 CSN_DESCR_BEGIN       (Multislot_capability_t)
-  M_NEXT_EXIST        (Multislot_capability_t, Exist_HSCSD_multislot_class, 1),
+  M_NEXT_EXIST_OR_NULL(Multislot_capability_t, Exist_HSCSD_multislot_class, 1),
   M_UINT              (Multislot_capability_t,  HSCSD_multislot_class,  5),
 
-  M_NEXT_EXIST        (Multislot_capability_t, Exist_GPRS_multislot_class, 2),
+  M_NEXT_EXIST_OR_NULL(Multislot_capability_t, Exist_GPRS_multislot_class, 2),
   M_UINT              (Multislot_capability_t,  GPRS_multislot_class,  5),
   M_UINT              (Multislot_capability_t,  GPRS_Extended_Dynamic_Allocation_Capability,  1),
 
-  M_NEXT_EXIST        (Multislot_capability_t, Exist_SM, 2),
+  M_NEXT_EXIST_OR_NULL(Multislot_capability_t, Exist_SM, 2),
   M_UINT              (Multislot_capability_t,  SMS_VALUE,  4),
   M_UINT              (Multislot_capability_t,  SM_VALUE,  4),
 
-  M_NEXT_EXIST        (Multislot_capability_t, Exist_ECSD_multislot_class, 1),
+  M_NEXT_EXIST_OR_NULL(Multislot_capability_t, Exist_ECSD_multislot_class, 1),
   M_UINT              (Multislot_capability_t,  ECSD_multislot_class,  5),
 
-  M_NEXT_EXIST        (Multislot_capability_t, Exist_EGPRS_multislot_class, 2),
+  M_NEXT_EXIST_OR_NULL(Multislot_capability_t, Exist_EGPRS_multislot_class, 2),
   M_UINT              (Multislot_capability_t,  EGPRS_multislot_class,  5),
   M_UINT              (Multislot_capability_t,  EGPRS_Extended_Dynamic_Allocation_Capability,  1),
 
-  M_NEXT_EXIST        (Multislot_capability_t, Exist_DTM_GPRS_multislot_class, 3),
+  M_NEXT_EXIST_OR_NULL(Multislot_capability_t, Exist_DTM_GPRS_multislot_class, 3),
   M_UINT              (Multislot_capability_t,  DTM_GPRS_multislot_class,  2),
   M_UINT              (Multislot_capability_t,  Single_Slot_DTM,  1),
   M_TYPE              (Multislot_capability_t, DTM_EGPRS_Params, DTM_EGPRS_t),
@@ -775,54 +805,54 @@ static const
 CSN_DESCR_BEGIN       (Content_t)
   M_UINT              (Content_t,  RF_Power_Capability,  3),
 
-  M_NEXT_EXIST        (Content_t, Exist_A5_bits, 1),
-  M_UINT              (Content_t,  A5_bits,  7),
+  M_NEXT_EXIST_OR_NULL(Content_t, Exist_A5_bits, 1),
+  M_UINT_OR_NULL      (Content_t,  A5_bits,  7),
 
-  M_UINT              (Content_t,  ES_IND,  1),
-  M_UINT              (Content_t,  PS,  1),
-  M_UINT              (Content_t,  VGCS,  1),
-  M_UINT              (Content_t,  VBS,  1),
+  M_UINT_OR_NULL      (Content_t,  ES_IND,  1),
+  M_UINT_OR_NULL      (Content_t,  PS,  1),
+  M_UINT_OR_NULL      (Content_t,  VGCS,  1),
+  M_UINT_OR_NULL      (Content_t,  VBS,  1),
 
   M_NEXT_EXIST_OR_NULL(Content_t, Exist_Multislot_capability, 1),
   M_TYPE              (Content_t, Multislot_capability, Multislot_capability_t),
 
-  M_NEXT_EXIST        (Content_t, Exist_Eight_PSK_Power_Capability, 1),
+  M_NEXT_EXIST_OR_NULL(Content_t,  Exist_Eight_PSK_Power_Capability, 1),
   M_UINT              (Content_t,  Eight_PSK_Power_Capability,  2),
 
-  M_UINT              (Content_t,  COMPACT_Interference_Measurement_Capability,  1),
-  M_UINT              (Content_t,  Revision_Level_Indicator,  1),
-  M_UINT              (Content_t,  UMTS_FDD_Radio_Access_Technology_Capability,  1),
-  M_UINT              (Content_t,  UMTS_384_TDD_Radio_Access_Technology_Capability,  1),
-  M_UINT              (Content_t,  CDMA2000_Radio_Access_Technology_Capability,  1),
+  M_UINT_OR_NULL      (Content_t,  COMPACT_Interference_Measurement_Capability,  1),
+  M_UINT_OR_NULL      (Content_t,  Revision_Level_Indicator,  1),
+  M_UINT_OR_NULL      (Content_t,  UMTS_FDD_Radio_Access_Technology_Capability,  1),
+  M_UINT_OR_NULL      (Content_t,  UMTS_384_TDD_Radio_Access_Technology_Capability,  1),
+  M_UINT_OR_NULL      (Content_t,  CDMA2000_Radio_Access_Technology_Capability,  1),
 
-  M_UINT              (Content_t,  UMTS_128_TDD_Radio_Access_Technology_Capability,  1),
-  M_UINT              (Content_t,  GERAN_Feature_Package_1,  1),
+  M_UINT_OR_NULL      (Content_t,  UMTS_128_TDD_Radio_Access_Technology_Capability,  1),
+  M_UINT_OR_NULL      (Content_t,  GERAN_Feature_Package_1,  1),
 
-  M_NEXT_EXIST        (Content_t, Exist_Extended_DTM_multislot_class, 2),
+  M_NEXT_EXIST_OR_NULL(Content_t,  Exist_Extended_DTM_multislot_class, 2),
   M_UINT              (Content_t,  Extended_DTM_GPRS_multislot_class,  2),
   M_UINT              (Content_t,  Extended_DTM_EGPRS_multislot_class,  2),
 
-  M_UINT              (Content_t,  Modulation_based_multislot_class_support,  1),
+  M_UINT_OR_NULL      (Content_t,  Modulation_based_multislot_class_support,  1),
 
-  M_NEXT_EXIST        (Content_t, Exist_HighMultislotCapability, 1),
+  M_NEXT_EXIST_OR_NULL(Content_t,  Exist_HighMultislotCapability, 1),
   M_UINT              (Content_t,  HighMultislotCapability,  2),
 
-  M_NEXT_EXIST        (Content_t, Exist_GERAN_lu_ModeCapability, 1),
+  M_NEXT_EXIST_OR_NULL(Content_t,  Exist_GERAN_lu_ModeCapability, 1),
   M_UINT              (Content_t,  GERAN_lu_ModeCapability,  4),
 
-  M_UINT              (Content_t,  GMSK_MultislotPowerProfile,  2),
-  M_UINT              (Content_t,  EightPSK_MultislotProfile,  2),
+  M_UINT_OR_NULL      (Content_t,  GMSK_MultislotPowerProfile,  2),
+  M_UINT_OR_NULL      (Content_t,  EightPSK_MultislotProfile,  2),
 
-  M_UINT              (Content_t,  MultipleTBF_Capability,  1),
-  M_UINT              (Content_t,  DownlinkAdvancedReceiverPerformance,  2),
-  M_UINT              (Content_t,  ExtendedRLC_MAC_ControlMessageSegmentionsCapability,  1),
-  M_UINT              (Content_t,  DTM_EnhancementsCapability,  1),
+  M_UINT_OR_NULL      (Content_t,  MultipleTBF_Capability,  1),
+  M_UINT_OR_NULL      (Content_t,  DownlinkAdvancedReceiverPerformance,  2),
+  M_UINT_OR_NULL      (Content_t,  ExtendedRLC_MAC_ControlMessageSegmentionsCapability,  1),
+  M_UINT_OR_NULL      (Content_t,  DTM_EnhancementsCapability,  1),
 
-  M_NEXT_EXIST        (Content_t, Exist_DTM_GPRS_HighMultislotClass, 2),
+  M_NEXT_EXIST_OR_NULL(Content_t, Exist_DTM_GPRS_HighMultislotClass, 2),
   M_UINT              (Content_t,  DTM_GPRS_HighMultislotClass,  3),
   M_TYPE              (Content_t, DTM_EGPRS_HighMultislotClass, DTM_EGPRS_HighMultislotClass_t),
 
-  M_UINT              (Content_t,  PS_HandoverCapability,  1),
+  M_UINT_OR_NULL      (Content_t,  PS_HandoverCapability,  1),
 CSN_DESCR_END         (Content_t)
 
 gint16 Content_Dissector(csnStream_t* ar, bitvec *vector, unsigned& readIndex, void* data)
@@ -864,12 +894,12 @@ gint16 Additional_access_technologies_Dissector(csnStream_t* ar, bitvec* vector,
 static const
 CSN_ChoiceElement_t MS_RA_capability_value_Choice[] =
 {
-  {4, AccTech_GSMP,     M_SERIALIZE (MS_RA_capability_value_t, u.Content, Content_Dissector)}, /* Long Form */
-  {4, AccTech_GSME,     M_SERIALIZE (MS_RA_capability_value_t, u.Content, Content_Dissector)}, /* Long Form */
-  {4, AccTech_GSM1800,  M_SERIALIZE (MS_RA_capability_value_t, u.Content, Content_Dissector)}, /* Long Form */
-  {4, AccTech_GSM1900,  M_SERIALIZE (MS_RA_capability_value_t, u.Content, Content_Dissector)}, /* Long Form */
-  {4, AccTech_GSM850,   M_SERIALIZE (MS_RA_capability_value_t, u.Content, Content_Dissector)}, /* Long Form */
-  {4, AccTech_GSMOther, M_SERIALIZE (MS_RA_capability_value_t, u.Additional_access_technologies, Additional_access_technologies_Dissector)}, /* Short Form */
+  {4, AccTech_GSMP,     M_SERIALIZE (MS_RA_capability_value_t, u.Content, 7, Content_Dissector)}, /* Long Form */
+  {4, AccTech_GSME,     M_SERIALIZE (MS_RA_capability_value_t, u.Content, 7, Content_Dissector)}, /* Long Form */
+  {4, AccTech_GSM1800,  M_SERIALIZE (MS_RA_capability_value_t, u.Content, 7, Content_Dissector)}, /* Long Form */
+  {4, AccTech_GSM1900,  M_SERIALIZE (MS_RA_capability_value_t, u.Content, 7, Content_Dissector)}, /* Long Form */
+  {4, AccTech_GSM850,   M_SERIALIZE (MS_RA_capability_value_t, u.Content, 7, Content_Dissector)}, /* Long Form */
+  {4, AccTech_GSMOther, M_SERIALIZE (MS_RA_capability_value_t, u.Additional_access_technologies, 7, Additional_access_technologies_Dissector)}, /* Short Form */
 };
 
 static const
@@ -883,7 +913,7 @@ CSN_DESCR_BEGIN (MS_Radio_Access_capability_t)
 /*M_UINT        (MS_Radio_Access_capability_t,  IEI,  8),*/
 /*M_UINT        (MS_Radio_Access_capability_t,  Length,  8),*/
 
-  M_REC_TARRAY_1(MS_Radio_Access_capability_t, MS_RA_capability_value[0], MS_RA_capability_value_t, Count_MS_RA_capability_value),
+  M_REC_TARRAY_1(MS_Radio_Access_capability_t, MS_RA_capability_value, MS_RA_capability_value_t, Count_MS_RA_capability_value),
 CSN_DESCR_END   (MS_Radio_Access_capability_t)
 
 /*< MS Classmark 3 IE >*/
@@ -1111,6 +1141,7 @@ CSN_DESCR_BEGIN       (Packet_Resource_Request_t)
 
   M_NEXT_EXIST_OR_NULL(Packet_Resource_Request_t, Exist_AdditionsR99, 1),
   M_TYPE              (Packet_Resource_Request_t, AdditionsR99, PRR_AdditionsR99_t),
+  M_PADDING_BITS     (Packet_Resource_Request_t),
 CSN_DESCR_END         (Packet_Resource_Request_t)
 
 /*< Packet Mobile TBF Status message content > */
@@ -1128,6 +1159,7 @@ CSN_DESCR_BEGIN(Packet_Mobile_TBF_Status_t)
 
   M_NEXT_EXIST (Packet_Mobile_TBF_Status_t, Exist_STATUS_MESSAGE_TYPE, 1),
   M_UINT       (Packet_Mobile_TBF_Status_t,  STATUS_MESSAGE_TYPE,  6),
+  M_PADDING_BITS(Packet_Mobile_TBF_Status_t),
 CSN_DESCR_END  (Packet_Mobile_TBF_Status_t)
 
 /*< Packet PSI Status message content > */
@@ -1166,6 +1198,7 @@ CSN_DESCR_BEGIN(Packet_PSI_Status_t)
   M_UINT       (Packet_PSI_Status_t,  PBCCH_CHANGE_MARK,  3),
   M_TYPE       (Packet_PSI_Status_t, PSI_Message_List, PSI_Message_List_t),
   M_TYPE       (Packet_PSI_Status_t, Unknown_PSI_Message_List, Unknown_PSI_Message_List_t),
+  M_PADDING_BITS(Packet_PSI_Status_t),
 CSN_DESCR_END  (Packet_PSI_Status_t)
 
 /* < Packet SI Status message content > */
@@ -1202,6 +1235,7 @@ CSN_DESCR_BEGIN(Packet_SI_Status_t)
   M_UINT       (Packet_SI_Status_t,  BCCH_CHANGE_MARK,  3),
   M_TYPE       (Packet_SI_Status_t, SI_Message_List, SI_Message_List_t),
   M_TYPE       (Packet_SI_Status_t, Unknown_SI_Message_List, Unknown_SI_Message_List_t),
+  M_PADDING_BITS(Packet_SI_Status_t),
 CSN_DESCR_END  (Packet_SI_Status_t)
 
 /* < Packet Downlink Ack/Nack message content > */
@@ -1227,6 +1261,7 @@ CSN_DESCR_BEGIN       (Packet_Downlink_Ack_Nack_t)
 
   M_NEXT_EXIST_OR_NULL(Packet_Downlink_Ack_Nack_t, Exist_AdditionsR99, 1),
   M_TYPE              (Packet_Downlink_Ack_Nack_t, AdditionsR99, PD_AckNack_AdditionsR99_t),
+  M_PADDING_BITS      (Packet_Downlink_Ack_Nack_t),
 CSN_DESCR_END         (Packet_Downlink_Ack_Nack_t)
 
 
@@ -1263,7 +1298,7 @@ CSN_DESCR_BEGIN(EGPRS_PD_AckNack_t)
 
   M_TYPE       (EGPRS_PD_AckNack_t, EGPRS_AckNack, EGPRS_AckNack_t),
 /*  M_CALLBACK   (EGPRS_PD_AckNack_t, (void*)24, EGPRS_AckNack, EGPRS_AckNack),  */
-  M_LEFT_VAR_BMP (EGPRS_PD_AckNack_t, EGPRS_AckNack.URBB, EGPRS_AckNack.URBB_LENGTH, 0),
+  M_PADDING_BITS(EGPRS_PD_AckNack_t),
 
 CSN_DESCR_END  (EGPRS_PD_AckNack_t)
 
@@ -1360,6 +1395,8 @@ CSN_DESCR_BEGIN(Packet_Cell_Change_Failure_t)
 
   M_NEXT_EXIST_OR_NULL (Packet_Cell_Change_Failure_t, Exist_AdditionsR99, 1),
   M_TYPE               (Packet_Cell_Change_Failure_t, AdditionsR99, PCCF_AdditionsR99_t),
+
+  M_PADDING_BITS       (Packet_Cell_Change_Failure_t),
 CSN_DESCR_END          (Packet_Cell_Change_Failure_t)
 
 /*< Packet Uplink Ack/Nack message content > */
@@ -1452,7 +1489,6 @@ CSN_DESCR_BEGIN(PU_AckNack_EGPRS_00_t)
 
   M_TYPE       (PU_AckNack_EGPRS_00_t, EGPRS_AckNack, EGPRS_AckNack_t),
 /*  M_CALLBACK   (PU_AckNack_EGPRS_00_t, (void*)24, EGPRS_AckNack, EGPRS_AckNack),  */
-  M_LEFT_VAR_BMP (PU_AckNack_EGPRS_00_t, EGPRS_AckNack.URBB, EGPRS_AckNack.URBB_LENGTH, 0),
 CSN_DESCR_END  (PU_AckNack_EGPRS_00_t)
 
 static const
@@ -1475,6 +1511,7 @@ CSN_DESCR_BEGIN(Packet_Uplink_Ack_Nack_t)
   M_UNION      (Packet_Uplink_Ack_Nack_t, 2),
   M_TYPE       (Packet_Uplink_Ack_Nack_t, u.PU_AckNack_GPRS_Struct, PU_AckNack_GPRS_t),
   M_TYPE       (Packet_Uplink_Ack_Nack_t, u.PU_AckNack_EGPRS_Struct, PU_AckNack_EGPRS_t),
+  M_PADDING_BITS(Packet_Uplink_Ack_Nack_t ),
 CSN_DESCR_END  (Packet_Uplink_Ack_Nack_t)
 
 /*< Packet Uplink Assignment message content > */
@@ -1813,6 +1850,8 @@ CSN_DESCR_BEGIN(Packet_Uplink_Assignment_t)
   M_UNION      (Packet_Uplink_Assignment_t, 2),
   M_TYPE       (Packet_Uplink_Assignment_t, u.PUA_GPRS_Struct, PUA_GPRS_t),
   M_TYPE       (Packet_Uplink_Assignment_t, u.PUA_EGPRS_Struct, PUA_EGPRS_t),
+
+  M_PADDING_BITS(Packet_Uplink_Assignment_t ),
 CSN_DESCR_END  (Packet_Uplink_Assignment_t)
 
 /*< Packet Downlink Assignment message content > */
@@ -1890,6 +1929,8 @@ CSN_DESCR_BEGIN       (Packet_Downlink_Assignment_t)
 
   M_NEXT_EXIST_OR_NULL(Packet_Downlink_Assignment_t, Exist_AdditionsR99, 1),
   M_TYPE              (Packet_Downlink_Assignment_t, AdditionsR99, PDA_AdditionsR99_t),
+
+  M_PADDING_BITS    (Packet_Downlink_Assignment_t),
 CSN_DESCR_END         (Packet_Downlink_Assignment_t)
 
 typedef Packet_Downlink_Assignment_t pdlaCheck_t;
@@ -2034,6 +2075,7 @@ CSN_DESCR_BEGIN(Packet_Paging_Request_t)
   M_UINT       (Packet_Paging_Request_t,  NLN,  2),
 
   M_REC_TARRAY (Packet_Paging_Request_t, Repeated_Page_info, Repeated_Page_info_t, Count_Repeated_Page_info),
+  M_PADDING_BITS(Packet_Paging_Request_t),
 CSN_DESCR_END  (Packet_Paging_Request_t)
 
 static const
@@ -2043,6 +2085,7 @@ CSN_DESCR_BEGIN(Packet_PDCH_Release_t)
 
   M_FIXED      (Packet_PDCH_Release_t, 1, 0x01),
   M_UINT       (Packet_PDCH_Release_t,  TIMESLOTS_AVAILABLE,  8),
+  M_PADDING_BITS(Packet_PDCH_Release_t),
 CSN_DESCR_END  (Packet_PDCH_Release_t)
 
 /*< Packet Power Control/Timing Advance message content >*/
@@ -2088,6 +2131,8 @@ CSN_DESCR_BEGIN(Packet_Power_Control_Timing_Advance_t)
   M_UNION      (Packet_Power_Control_Timing_Advance_t, 2),
   M_TYPE       (Packet_Power_Control_Timing_Advance_t, u.GlobalTimingAndPower, GlobalTimingAndPower_t),
   M_TYPE       (Packet_Power_Control_Timing_Advance_t, u.GlobalTimingOrPower, GlobalTimingOrPower_t),
+
+  M_PADDING_BITS(Packet_Power_Control_Timing_Advance_t),
 CSN_DESCR_END  (Packet_Power_Control_Timing_Advance_t)
 
 /*< Packet Queueing Notification message content > */
@@ -2100,6 +2145,7 @@ CSN_DESCR_BEGIN(Packet_Queueing_Notification_t)
   M_TYPE       (Packet_Queueing_Notification_t, Packet_Request_Reference, Packet_Request_Reference_t),
 
   M_UINT       (Packet_Queueing_Notification_t,  TQI,  16),
+  M_PADDING_BITS(Packet_Queueing_Notification_t),
 CSN_DESCR_END  (Packet_Queueing_Notification_t)
 
 /* USED in Packet Timeslot Reconfigure message content
@@ -2220,6 +2266,8 @@ CSN_DESCR_BEGIN(Packet_Timeslot_Reconfigure_t)
   M_UNION      (Packet_Timeslot_Reconfigure_t, 2),
   M_TYPE       (Packet_Timeslot_Reconfigure_t, u.PTR_GPRS_Struct, PTR_GPRS_t),
   M_TYPE       (Packet_Timeslot_Reconfigure_t, u.PTR_EGPRS_Struct, PTR_EGPRS_t),
+
+  M_PADDING_BITS(Packet_Timeslot_Reconfigure_t),
 CSN_DESCR_END  (Packet_Timeslot_Reconfigure_t)
 
 typedef Packet_Timeslot_Reconfigure_t PTRCheck_t;
@@ -2332,6 +2380,7 @@ CSN_DESCR_BEGIN(Packet_PRACH_Parameters_t)
   M_UINT       (Packet_PRACH_Parameters_t,  PAGE_MODE,  2),
 
   M_TYPE       (Packet_PRACH_Parameters_t, PRACH_Control, PRACH_Control_t),
+  M_PADDING_BITS(Packet_PRACH_Parameters_t),
 CSN_DESCR_END  (Packet_PRACH_Parameters_t)
 
 /* < Packet Access Reject message content > */
@@ -2364,6 +2413,7 @@ CSN_DESCR_BEGIN(Packet_Access_Reject_t)
 
   M_TYPE       (Packet_Access_Reject_t, Reject, Reject_t),
   M_REC_TARRAY (Packet_Access_Reject_t, Reject[1], Reject_t, Count_Reject),
+  M_PADDING_BITS(Packet_Access_Reject_t),
 CSN_DESCR_END  (Packet_Access_Reject_t)
 
 /* < Packet Cell Change Order message content > */
@@ -3273,6 +3323,8 @@ CSN_DESCR_BEGIN(Packet_Cell_Change_Order_t)
   M_UNION      (Packet_Cell_Change_Order_t, 2),
   M_TYPE       (Packet_Cell_Change_Order_t, u.Target_Cell_GSM, Target_Cell_GSM_t),
   M_TYPE       (Packet_Cell_Change_Order_t, u.Target_Cell_3G, Target_Cell_3G_t),
+
+  M_PADDING_BITS(Packet_Cell_Change_Order_t),
 CSN_DESCR_END  (Packet_Cell_Change_Order_t)
 
 /*< Packet (Enhanced) Measurement Report message contents > */
@@ -3496,6 +3548,8 @@ CSN_DESCR_BEGIN       (Packet_Measurement_Report_t)
 
   M_NEXT_EXIST_OR_NULL(Packet_Measurement_Report_t, Exist_AdditionsR99, 1),
   M_TYPE              (Packet_Measurement_Report_t, AdditionsR99, PMR_AdditionsR99_t),
+
+  M_PADDING_BITS      (Packet_Measurement_Report_t),
 CSN_DESCR_END         (Packet_Measurement_Report_t)
 
 static const
@@ -3546,6 +3600,8 @@ CSN_DESCR_BEGIN       (Packet_Enh_Measurement_Report_t)
 
   M_NEXT_EXIST_OR_NULL(Packet_Enh_Measurement_Report_t, Exist_AdditionsR5, 1),
   M_TYPE              (Packet_Enh_Measurement_Report_t, AdditionsR5, PEMR_AdditionsR5_t),
+
+  M_PADDING_BITS(Packet_Enh_Measurement_Report_t),
 CSN_DESCR_END         (Packet_Enh_Measurement_Report_t)
 
 /*< Packet Measurement Order message contents >*/
@@ -3579,6 +3635,8 @@ CSN_DESCR_BEGIN        (Packet_Measurement_Order_t)
 
   M_NEXT_EXIST_OR_NULL (Packet_Measurement_Order_t, Exist_AdditionsR98, 1),
   M_TYPE               (Packet_Measurement_Order_t, AdditionsR98, PMO_AdditionsR98_t),
+
+  M_PADDING_BITS       (Packet_Measurement_Order_t),
 CSN_DESCR_END          (Packet_Measurement_Order_t)
 
 static const
@@ -3724,6 +3782,8 @@ CSN_DESCR_BEGIN(Packet_Cell_Change_Notification_t)
 
   M_NEXT_EXIST_OR_NULL(Packet_Cell_Change_Notification_t, Exist_AdditionsR6, 1),
   M_TYPE              (Packet_Cell_Change_Notification_t, AdditionsR6, PCCN_AdditionsR6_t),
+
+  M_PADDING_BITS(Packet_Cell_Change_Notification_t),
 CSN_DESCR_END  (Packet_Cell_Change_Notification_t)
 
 /*< Packet Cell Change Continue message contents > */
@@ -3738,6 +3798,8 @@ CSN_DESCR_BEGIN(Packet_Cell_Change_Continue_t)
   M_UINT       (Packet_Cell_Change_Continue_t,  ARFCN, 10),
   M_UINT       (Packet_Cell_Change_Continue_t,  BSIC,  6),
   M_UINT       (Packet_Cell_Change_Continue_t,  CONTAINER_ID,  2),
+
+  M_PADDING_BITS(Packet_Cell_Change_Continue_t),
 CSN_DESCR_END  (Packet_Cell_Change_Continue_t)
 
 /*< Packet Neighbour Cell Data message contents > */
@@ -3777,6 +3839,7 @@ CSN_DESCR_BEGIN(Packet_Neighbour_Cell_Data_t)
   M_UINT       (Packet_Neighbour_Cell_Data_t,  CONTAINER_INDEX,  5),
 
   M_TYPE       (Packet_Neighbour_Cell_Data_t, Container, PNCDContainer_t),
+  M_PADDING_BITS(Packet_Neighbour_Cell_Data_t),
 CSN_DESCR_END  (Packet_Neighbour_Cell_Data_t)
 
 /*< Packet Serving Cell Data message contents > */
@@ -3790,6 +3853,7 @@ CSN_DESCR_BEGIN(Packet_Serving_Cell_Data_t)
   M_UINT       (Packet_Serving_Cell_Data_t,  spare,  4),
   M_UINT       (Packet_Serving_Cell_Data_t,  CONTAINER_INDEX,  5),
   M_UINT_ARRAY (Packet_Serving_Cell_Data_t, CONTAINER, 8, 19),/* 8*19 bits */
+  M_PADDING_BITS(Packet_Serving_Cell_Data_t),
 CSN_DESCR_END  (Packet_Serving_Cell_Data_t)
 
 
@@ -4033,6 +4097,8 @@ CSN_DESCR_BEGIN(Packet_Handover_Command_t)
   M_TYPE       (Packet_Handover_Command_t, u.PS_HandoverTo_UTRAN_Payload, PS_HandoverTo_UTRAN_Payload_t),
   CSN_ERROR    (Packet_Handover_Command_t, "10 <extension> not implemented", CSN_ERROR_STREAM_NOT_SUPPORTED),
   CSN_ERROR    (Packet_Handover_Command_t, "11 <extension> not implemented", CSN_ERROR_STREAM_NOT_SUPPORTED),
+
+  M_PADDING_BITS(Packet_Handover_Command_t),
 CSN_DESCR_END  (Packet_Handover_Command_t)
 
 /*< End Packet Handover Command >*/
@@ -4047,6 +4113,7 @@ CSN_DESCR_BEGIN(Packet_PhysicalInformation_t)
   M_TYPE       (Packet_PhysicalInformation_t, Global_TFI, Global_TFI_t),
 
   M_UINT       (Packet_PhysicalInformation_t,  TimingAdvance,  8),
+  M_PADDING_BITS(Packet_PhysicalInformation_t),
 CSN_DESCR_END  (Packet_PhysicalInformation_t)
 
 /*< End Packet Physical Information > */
@@ -4077,6 +4144,7 @@ CSN_DESCR_BEGIN       (Additional_MS_Rad_Access_Cap_t)
 
   M_TYPE              (Additional_MS_Rad_Access_Cap_t,  ID, AdditionalMsRadAccessCapID_t),
   M_TYPE              (Additional_MS_Rad_Access_Cap_t,  MS_Radio_Access_capability, MS_Radio_Access_capability_t),
+  M_PADDING_BITS      (Additional_MS_Rad_Access_Cap_t),
 CSN_DESCR_END         (Additional_MS_Rad_Access_Cap_t)
 
 
@@ -4090,6 +4158,7 @@ CSN_DESCR_BEGIN       (Packet_Pause_t)
   M_UINT              (Packet_Pause_t,  MESSAGE_TYPE,  2),
   M_UINT              (Packet_Pause_t,  TLLI, 32),
   M_BITMAP            (Packet_Pause_t,  RAI, 48),
+  M_PADDING_BITS      (Packet_Pause_t),
 CSN_DESCR_END         (Packet_Pause_t)
 
 
@@ -4135,6 +4204,8 @@ CSN_DESCR_BEGIN(PSI1_t)
 
   M_NEXT_EXIST (PSI1_t, Exist_AdditionsR99, 1),
   M_TYPE       (PSI1_t,  AdditionsR99, PSI1_AdditionsR99_t),
+
+  M_PADDING_BITS(PSI1_t),
 CSN_DESCR_END  (PSI1_t)
 /*< End Packet System Information Type 1 message content >*/
 
@@ -4240,6 +4311,7 @@ CSN_DESCR_BEGIN(PSI2_t)
   M_TYPE       (PSI2_t,  Cell_Allocation, Cell_Allocation_t),
   M_REC_TARRAY (PSI2_t, GPRS_MA[0], PSI2_MA_t, Count_GPRS_MA),
   M_REC_TARRAY (PSI2_t, PCCCH_Description[0], PCCCH_Description_t, Count_PCCCH_Description),
+  M_PADDING_BITS(PSI2_t),
 CSN_DESCR_END  (PSI2_t)
 /*< End Packet System Information Type 2 message content >*/
 
@@ -4364,6 +4436,8 @@ CSN_DESCR_BEGIN(PSI3_t)
   
   M_NEXT_EXIST (PSI3_t, Exist_AdditionR98, 1),
   M_TYPE       (PSI3_t,  AdditionR98, PSI3_AdditionR98_t),
+
+  M_PADDING_BITS(PSI3_t),
 CSN_DESCR_END  (PSI3_t)
 /*< End Packet System Information Type 3 message content >*/
 
@@ -4472,6 +4546,8 @@ CSN_DESCR_BEGIN(PSI5_t)
 
   M_NEXT_EXIST (PSI5_t, Exist_AdditionsR99, 1),
   M_TYPE       (PSI5_t,  AdditionsR99, PSI5_AdditionsR99),
+
+  M_PADDING_BITS(PSI5_t),
 CSN_DESCR_END  (PSI5_t)
 /*< End Packet System Information Type 5 message content >*/
 
@@ -4515,6 +4591,8 @@ CSN_DESCR_BEGIN(PSI13_t)
 
   M_NEXT_EXIST (PSI13_t, Exist_AdditionsR99, 1),
   M_TYPE       (PSI13_t,  AdditionsR99, PSI13_AdditionR99),
+
+  M_PADDING_BITS(PSI13_t),
 CSN_DESCR_END  (PSI13_t)
 /*< End Packet System Information Type 13 message content >*/
 
@@ -4732,7 +4810,7 @@ void decode_gsm_rlcmac_uplink(bitvec * vector, RlcMacUplink_t * data)
     LOGPC(DRLCMACDATA, LOGL_NOTICE, "Payload Type: RESERVED (3)");
     return;
   }
-  data->NrOfBits = (23 - 1) * 8;
+  data->NrOfBits = 23 * 8;
   csnStreamInit(&ar, 0, data->NrOfBits);
   readIndex += 6;
   data->u.MESSAGE_TYPE = bitvec_read_field(vector, readIndex, 6);
@@ -5017,7 +5095,7 @@ void encode_gsm_rlcmac_uplink(bitvec * vector, RlcMacUplink_t * data)
 {
   csnStream_t      ar;
   unsigned writeIndex = 0;
-  data->NrOfBits = (23 - 1) * 8;
+  data->NrOfBits = 23 * 8;
   csnStreamInit(&ar, 0, data->NrOfBits);
   writeIndex = 0;
   switch (data->u.MESSAGE_TYPE)