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packet-gtp.c

/* packet-gtp.c
 *
 * Routines for GTP dissection
 * Copyright 2001, Michal Melerowicz <michal.melerowicz@nokia.com>
 *                 Nicolas Balkota <balkota@mac.com>
 *
 * $Id: packet-gtp.c 12835 2004-12-26 00:22:16Z guy $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 1998 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <glib.h>

#include <epan/packet.h>
#include <epan/prefs.h>
#include "packet-gtp.h"
#include "packet-ipv6.h"
#include "packet-ppp.h"

static dissector_table_t ppp_subdissector_table;

#define GTPv0_PORT 3386
#define GTPv1C_PORT 2123                  /* 3G Control PDU */
#define GTPv1U_PORT 2152                  /* 3G T-PDU */

#define GTPv0_HDR_LENGTH 20
#define GTPv1_HDR_LENGTH 12
#define GTP_PRIME_HDR_LENGTH 6

/* to check compliance with ETSI  */
#define GTP_MANDATORY   1
#define GTP_OPTIONAL    2
#define GTP_CONDITIONAL 4

static int g_gtpv0_port       = GTPv0_PORT;
static int g_gtpv1c_port      = GTPv1C_PORT;
static int g_gtpv1u_port      = GTPv1U_PORT;

void proto_reg_handoff_gtp(void);

static int proto_gtp          = -1;

static int hf_gtp_apn               = -1;
static int hf_gtp_cause             = -1;
static int hf_gtp_chrg_char         = -1;
static int hf_gtp_chrg_char_s       = -1;
static int hf_gtp_chrg_char_n       = -1;
static int hf_gtp_chrg_char_p       = -1;
static int hf_gtp_chrg_char_f       = -1;
static int hf_gtp_chrg_char_h       = -1;
static int hf_gtp_chrg_char_r       = -1;
static int hf_gtp_chrg_id           = -1;
static int hf_gtp_chrg_ipv4         = -1;
static int hf_gtp_chrg_ipv6         = -1;
static int hf_gtp_ext_flow_label    = -1;
static int hf_gtp_ext_id            = -1;
static int hf_gtp_ext_val           = -1;
static int hf_gtp_flags             = -1;
static int hf_gtp_flags_ver         = -1;
static int hf_gtp_flags_pt          = -1;
static int hf_gtp_flags_spare1            = -1;
static int hf_gtp_flags_snn         = -1;
static int hf_gtp_flags_spare2            = -1;
static int hf_gtp_flags_e           = -1;
static int hf_gtp_flags_s           = -1;
static int hf_gtp_flags_pn          = -1;
static int hf_gtp_flow_ii           = -1;
static int hf_gtp_flow_label        = -1;
static int hf_gtp_flow_sig          = -1;
static int hf_gtp_gsn_addr_len            = -1;
static int hf_gtp_gsn_addr_type           = -1;
static int hf_gtp_gsn_ipv4          = -1;
static int hf_gtp_gsn_ipv6          = -1;
static int hf_gtp_imsi              = -1;
static int hf_gtp_length            = -1;
static int hf_gtp_map_cause         = -1;
static int hf_gtp_message_type            = -1;
static int hf_gtp_ms_reason         = -1;
static int hf_gtp_ms_valid          = -1;
static int hf_gtp_msisdn            = -1;
static int hf_gtp_next              = -1;
static int hf_gtp_npdu_number       = -1;
static int hf_gtp_node_ipv4         = -1;
static int hf_gtp_node_ipv6         = -1;
static int hf_gtp_nsapi             = -1;
static int hf_gtp_ptmsi             = -1;
static int hf_gtp_ptmsi_sig         = -1;
static int hf_gtp_qos_version       = -1;
static int hf_gtp_qos_spare1        = -1;
static int hf_gtp_qos_delay         = -1;
static int hf_gtp_qos_mean          = -1;
static int hf_gtp_qos_peak          = -1;
static int hf_gtp_qos_spare2        = -1;
static int hf_gtp_qos_precedence    = -1;
static int hf_gtp_qos_spare3        = -1;
static int hf_gtp_qos_reliability   = -1;
static int hf_gtp_qos_al_ret_priority     = -1;
static int hf_gtp_qos_traf_class    = -1;
static int hf_gtp_qos_del_order           = -1;
static int hf_gtp_qos_del_err_sdu   = -1;
static int hf_gtp_qos_max_sdu_size  = -1;
static int hf_gtp_qos_max_ul        = -1;
static int hf_gtp_qos_max_dl        = -1;
static int hf_gtp_qos_res_ber       = -1;
static int hf_gtp_qos_sdu_err_ratio = -1;
static int hf_gtp_qos_trans_delay   = -1;
static int hf_gtp_qos_traf_handl_prio     = -1;
static int hf_gtp_qos_guar_ul       = -1;
static int hf_gtp_qos_guar_dl       = -1;
static int hf_gtp_pkt_flow_id       = -1;
static int hf_gtp_rab_gtpu_dn       = -1;
static int hf_gtp_rab_gtpu_up       = -1;
static int hf_gtp_rab_pdu_dn        = -1;
static int hf_gtp_rab_pdu_up        = -1;
static int hf_gtp_rai_mcc           = -1;
static int hf_gtp_rai_mnc           = -1;
static int hf_gtp_rai_rac           = -1;
static int hf_gtp_rai_lac           = -1;
static int hf_gtp_ranap_cause       = -1;
static int hf_gtp_recovery          = -1;
static int hf_gtp_reorder           = -1;
static int hf_gtp_rnc_ipv4          = -1;
static int hf_gtp_rnc_ipv6          = -1;
static int hf_gtp_rp                = -1;
static int hf_gtp_rp_nsapi          = -1;
static int hf_gtp_rp_sms            = -1;
static int hf_gtp_rp_spare          = -1;
static int hf_gtp_sel_mode          = -1;
static int hf_gtp_seq_number        = -1;
static int hf_gtp_sndcp_number            = -1;
static int hf_gtp_tear_ind          = -1;
static int hf_gtp_teid              = -1;
static int hf_gtp_teid_cp           = -1;
static int hf_gtp_teid_data         = -1;
static int hf_gtp_teid_ii           = -1;
static int hf_gtp_tft_code          = -1;
static int hf_gtp_tft_spare         = -1;
static int hf_gtp_tft_number        = -1;
static int hf_gtp_tft_eval          = -1;
static int hf_gtp_tid               = -1;
static int hf_gtp_tlli              = -1;
static int hf_gtp_tr_comm           = -1;
static int hf_gtp_trace_ref         = -1;
static int hf_gtp_trace_type        = -1;
static int hf_gtp_unknown           = -1;
static int hf_gtp_user_addr_pdp_org = -1;
static int hf_gtp_user_addr_pdp_type      = -1;
static int hf_gtp_user_ipv4         = -1;
static int hf_gtp_user_ipv6         = -1;

/* Initialize the subtree pointers */
static gint ett_gtp                 = -1;
static gint ett_gtp_flags           = -1;
static gint ett_gtp_ext             = -1;
static gint ett_gtp_rai             = -1;
static gint ett_gtp_qos             = -1;
static gint ett_gtp_auth_tri        = -1;
static gint ett_gtp_flow_ii         = -1;
static gint ett_gtp_rab_cntxt       = -1;
static gint ett_gtp_rp              = -1;
static gint ett_gtp_pkt_flow_id           = -1;
static gint ett_gtp_chrg_char       = -1;
static gint ett_gtp_user            = -1;
static gint ett_gtp_mm              = -1;
static gint ett_gtp_trip            = -1;
static gint ett_gtp_quint           = -1;
static gint ett_gtp_pdp             = -1;
static gint ett_gtp_apn             = -1;
static gint ett_gtp_proto           = -1;
static gint ett_gtp_gsn_addr        = -1;
static gint ett_gtp_tft             = -1;
static gint ett_gtp_tft_pf          = -1;
static gint ett_gtp_tft_flags       = -1;
static gint ett_gtp_rab_setup       = -1;
static gint ett_gtp_hdr_list        = -1;
static gint ett_gtp_chrg_addr       = -1;
static gint ett_gtp_node_addr       = -1;
static gint ett_gtp_rel_pack        = -1;
static gint ett_gtp_can_pack        = -1;
static gint ett_gtp_data_resp       = -1;
static gint ett_gtp_priv_ext        = -1;

static gboolean   gtp_tpdu          = TRUE;
static gboolean   gtp_etsi_order          = FALSE;
static int  gtpv0_port        = 0;
static int  gtpv1c_port       = 0;
static int  gtpv1u_port       = 0;

/* Definition of flags masks */
#define GTP_VER_MASK 0xE0

static const value_string ver_types[] = {
      { 0, "GTP release 97/98 version" },
      { 1, "GTP release 99 version" },
      { 2, "None" },
      { 3, "None" },
      { 4, "None" },
      { 5, "None" },
      { 6, "None" },
      { 7, "None" },
      { 0, NULL }
};

#define GTP_PT_MASK           0x10
#define GTP_SPARE1_MASK       0x0E
#define GTP_SPARE2_MASK       0x08
#define GTP_E_MASK            0x04
#define GTP_S_MASK            0x02
#define GTP_SNN_MASK          0x01
#define GTP_PN_MASK           0x01

/* Definition of 3G charging characteristics masks */
#define GTP_MASK_CHRG_CHAR_S  0xF000
#define GTP_MASK_CHRG_CHAR_N  0x0800
#define GTP_MASK_CHRG_CHAR_P  0x0400
#define GTP_MASK_CHRG_CHAR_F  0x0200
#define GTP_MASK_CHRG_CHAR_H  0x0100
#define GTP_MASK_CHRG_CHAR_R  0x00FF

/* Traffic Flow Templates  mask */
#define GTPv1_TFT_CODE_MASK   0xE0
#define GTPv1_TFT_SPARE_MASK  0x10
#define GTPv1_TFT_NUMBER_MASK 0x0F

/* Definition of GSN Address masks */
#define GTP_EXT_GSN_ADDR_TYPE_MASK        0xC0
#define GTP_EXT_GSN_ADDR_LEN_MASK         0x3F

/* Definition of QoS masks */
#define GTP_EXT_QOS_SPARE1_MASK                 0xC0
#define GTP_EXT_QOS_DELAY_MASK                  0x38
#define GTP_EXT_QOS_RELIABILITY_MASK            0x07
#define GTP_EXT_QOS_PEAK_MASK             0xF0
#define GTP_EXT_QOS_SPARE2_MASK                 0x08
#define GTP_EXT_QOS_PRECEDENCE_MASK       0x07
#define GTP_EXT_QOS_SPARE3_MASK                 0xE0
#define GTP_EXT_QOS_MEAN_MASK             0x1F
#define GTP_EXT_QOS_TRAF_CLASS_MASK       0xE0
#define GTP_EXT_QOS_DEL_ORDER_MASK        0x18
#define GTP_EXT_QOS_DEL_ERR_SDU_MASK            0x07
#define GTP_EXT_QOS_RES_BER_MASK          0xF0
#define GTP_EXT_QOS_SDU_ERR_RATIO_MASK          0x0F
#define GTP_EXT_QOS_TRANS_DELAY_MASK            0xFC
#define GTP_EXT_QOS_TRAF_HANDL_PRIORITY_MASK    0x03

/* Definition of Radio Priority's masks */
#define GTPv1_EXT_RP_NSAPI_MASK                 0xF0
#define GTPv1_EXT_RP_SPARE_MASK                 0x08
#define GTPv1_EXT_RP_MASK                 0x07

/* definitions of GTP messages */
#define GTP_MSG_UNKNOWN             0x00
#define GTP_MSG_ECHO_REQ            0x01
#define GTP_MSG_ECHO_RESP           0x02
#define GTP_MSG_VER_NOT_SUPP        0x03
#define GTP_MSG_NODE_ALIVE_REQ            0x04
#define GTP_MSG_NODE_ALIVE_RESP           0x05
#define GTP_MSG_REDIR_REQ           0x06
#define GTP_MSG_REDIR_RESP          0x07
#define GTP_MSG_CREATE_PDP_REQ            0x10
#define GTP_MSG_CREATE_PDP_RESP           0x11
#define GTP_MSG_UPDATE_PDP_REQ            0x12
#define GTP_MSG_UPDATE_PDP_RESP           0x13
#define GTP_MSG_DELETE_PDP_REQ            0x14
#define GTP_MSG_DELETE_PDP_RESP           0x15
#define GTP_MSG_CREATE_AA_PDP_REQ   0x16  /* 2G */
#define GTP_MSG_CREATE_AA_PDP_RESP  0x17  /* 2G */
#define GTP_MSG_DELETE_AA_PDP_REQ   0x18  /* 2G */
#define GTP_MSG_DELETE_AA_PDP_RESP  0x19  /* 2G */
#define GTP_MSG_ERR_IND             0x1A
#define GTP_MSG_PDU_NOTIFY_REQ            0x1B
#define GTP_MSG_PDU_NOTIFY_RESP           0x1C
#define GTP_MSG_PDU_NOTIFY_REJ_REQ  0x1D
#define GTP_MSG_PDU_NOTIFY_REJ_RESP 0x1E
#define GTP_MSG_SUPP_EXT_HDR        0x1F
#define GTP_MSG_SEND_ROUT_INFO_REQ  0x20
#define GTP_MSG_SEND_ROUT_INFO_RESP 0x21
#define GTP_MSG_FAIL_REP_REQ        0x22
#define GTP_MSG_FAIL_REP_RESP       0x23
#define GTP_MSG_MS_PRESENT_REQ            0x24
#define GTP_MSG_MS_PRESENT_RESP           0x25
#define GTP_MSG_IDENT_REQ           0x30
#define GTP_MSG_IDENT_RESP          0x31
#define GTP_MSG_SGSN_CNTXT_REQ            0x32
#define GTP_MSG_SGSN_CNTXT_RESP           0x33
#define GTP_MSG_SGSN_CNTXT_ACK            0x34
#define GTP_MSG_FORW_RELOC_REQ            0x35
#define GTP_MSG_FORW_RELOC_RESP           0x36
#define GTP_MSG_FORW_RELOC_COMP           0x37
#define GTP_MSG_RELOC_CANCEL_REQ    0x38
#define GTP_MSG_RELOC_CANCEL_RESP   0x39
#define GTP_MSG_FORW_SRNS_CNTXT           0x3A
#define GTP_MSG_FORW_RELOC_ACK            0x3B
#define GTP_MSG_FORW_SRNS_CNTXT_ACK 0x3C
#define GTP_MSG_DATA_TRANSF_REQ           0xF0
#define GTP_MSG_DATA_TRANSF_RESP    0xF1
#define GTP_MSG_TPDU                0xFF

static const value_string message_type[] = {
      { GTP_MSG_UNKNOWN,            "For future use" },
      { GTP_MSG_ECHO_REQ,           "Echo request" },
      { GTP_MSG_ECHO_RESP,          "Echo response" },
      { GTP_MSG_VER_NOT_SUPP,       "Version not supported" },
      { GTP_MSG_NODE_ALIVE_REQ,     "Node alive request" },
      { GTP_MSG_NODE_ALIVE_RESP,    "Node alive response" },
      { GTP_MSG_REDIR_REQ,          "Redirection request" },
      { GTP_MSG_REDIR_RESP,         "Redirection response" },
      { GTP_MSG_CREATE_PDP_REQ,     "Create PDP context request" },
      { GTP_MSG_CREATE_PDP_RESP,    "Create PDP context response" },
      { GTP_MSG_UPDATE_PDP_REQ,     "Update PDP context request" },
      { GTP_MSG_UPDATE_PDP_RESP,    "Update PDP context response" },
      { GTP_MSG_DELETE_PDP_REQ,     "Delete PDP context request" },
      { GTP_MSG_DELETE_PDP_RESP,    "Delete PDP context response" },
      { GTP_MSG_CREATE_AA_PDP_REQ,  "Create AA PDP Context Request" },
      { GTP_MSG_CREATE_AA_PDP_RESP, "Create AA PDP Context Response" },
      { GTP_MSG_DELETE_AA_PDP_REQ,  "Delete AA PDP Context Request" },
      { GTP_MSG_DELETE_AA_PDP_RESP, "Delete AA PDP Context Response" },
      { GTP_MSG_ERR_IND,            "Error indication" },
      { GTP_MSG_PDU_NOTIFY_REQ,     "PDU notification request" },
      { GTP_MSG_PDU_NOTIFY_RESP,    "PDU notification response" },
      { GTP_MSG_PDU_NOTIFY_REJ_REQ, "PDU notification reject request" },
      { GTP_MSG_PDU_NOTIFY_REJ_RESP,      "PDU notification reject response" },
      { GTP_MSG_SUPP_EXT_HDR,       "Supported extension header notification" },
      { GTP_MSG_SEND_ROUT_INFO_REQ, "Send routing information for GPRS request" },
      { GTP_MSG_SEND_ROUT_INFO_RESP,      "Send routing information for GPRS response" },
      { GTP_MSG_FAIL_REP_REQ,       "Failure report request" },
      { GTP_MSG_FAIL_REP_RESP,      "Failure report response" },
      { GTP_MSG_MS_PRESENT_REQ,     "Note MS GPRS present request" },
      { GTP_MSG_MS_PRESENT_RESP,    "Note MS GPRS present response" },
      { GTP_MSG_IDENT_REQ,          "Identification request" },
      { GTP_MSG_IDENT_RESP,         "Identification response" },
      { GTP_MSG_SGSN_CNTXT_REQ,     "SGSN context request" },
      { GTP_MSG_SGSN_CNTXT_RESP,    "SGSN context response" },
      { GTP_MSG_SGSN_CNTXT_ACK,     "SGSN context acknowledgement" },
      { GTP_MSG_FORW_RELOC_REQ,     "Forward relocation request" },
      { GTP_MSG_FORW_RELOC_RESP,    "Forward relocation response" },
      { GTP_MSG_FORW_RELOC_COMP,    "Forward relocation complete" },
      { GTP_MSG_RELOC_CANCEL_REQ,   "Relocation cancel request" },
      { GTP_MSG_RELOC_CANCEL_RESP,  "Relocation cancel response" },
      { GTP_MSG_FORW_SRNS_CNTXT,    "Forward SRNS context" },
      { GTP_MSG_FORW_RELOC_ACK,     "Forward relocation complete acknowledge" },
      { GTP_MSG_FORW_SRNS_CNTXT_ACK,      "Forward SRNS context acknowledge" },
      { GTP_MSG_DATA_TRANSF_REQ,    "Data record transfer request" },
      { GTP_MSG_DATA_TRANSF_RESP,   "Data record transfer response" },
      { GTP_MSG_TPDU,               "T-PDU" },
      { 0, NULL }
};

/* definitions of fields in extension header */
#define GTP_EXT_CAUSE         0x01
#define GTP_EXT_IMSI          0x02
#define GTP_EXT_RAI           0x03
#define GTP_EXT_TLLI          0x04
#define GTP_EXT_PTMSI         0x05
#define GTP_EXT_QOS_GPRS      0x06
#define GTP_EXT_REORDER       0x08
#define GTP_EXT_AUTH_TRI      0x09
#define GTP_EXT_MAP_CAUSE     0x0B
#define GTP_EXT_PTMSI_SIG     0x0C
#define GTP_EXT_MS_VALID      0x0D
#define GTP_EXT_RECOVER       0x0E
#define GTP_EXT_SEL_MODE      0x0F

#define GTP_EXT_16            0x10
#define GTP_EXT_FLOW_LABEL    0x10
#define GTP_EXT_TEID          0x10  /* 0xFF10 3G */

#define GTP_EXT_17            0x11
#define GTP_EXT_FLOW_SIG      0x11
#define GTP_EXT_TEID_CP       0x11  /* 0xFF11 3G */

#define GTP_EXT_18            0x12
#define GTP_EXT_FLOW_II       0x12
#define GTP_EXT_TEID_II       0x12  /* 0xFF12 3G*/

#define GTP_EXT_19            0x13
#define GTP_EXT_MS_REASON     0x13  /* same as 0x1D GTPv1_EXT_MS_REASON */
#define GTP_EXT_TEAR_IND      0x13  /* 0xFF13 3G*/

#define GTP_EXT_NSAPI         0x14  /* 3G */
#define GTP_EXT_RANAP_CAUSE   0x15  /* 3G */
#define GTP_EXT_RAB_CNTXT     0x16  /* 3G */
#define GTP_EXT_RP_SMS        0x17  /* 3G */
#define GTP_EXT_RP            0x18  /* 3G */
#define GTP_EXT_PKT_FLOW_ID   0x19  /* 3G */
#define GTP_EXT_CHRG_CHAR     0x1A  /* 3G */
#define GTP_EXT_TRACE_REF     0x1B  /* 3G */
#define GTP_EXT_TRACE_TYPE    0x1C  /* 3G */
#define GTPv1_EXT_MS_REASON   0x1D  /* 3G */
#define GTP_EXT_TR_COMM       0x7E  /* charging */
#define GTP_EXT_CHRG_ID       0x7F
#define GTP_EXT_USER_ADDR     0x80
#define GTP_EXT_MM_CNTXT      0x81
#define GTP_EXT_PDP_CNTXT     0x82
#define GTP_EXT_APN           0x83
#define GTP_EXT_PROTO_CONF    0x84
#define GTP_EXT_GSN_ADDR      0x85
#define GTP_EXT_MSISDN        0x86
#define GTP_EXT_QOS_UMTS      0x87  /* 3G */
#define GTP_EXT_AUTH_QUI      0x88  /* 3G */
#define GTP_EXT_TFT           0x89  /* 3G */
#define GTP_EXT_TARGET_ID     0x8A  /* 3G */
#define GTP_EXT_UTRAN_CONT    0x8B  /* 3G */
#define GTP_EXT_RAB_SETUP     0x8C  /* 3G */
#define GTP_EXT_HDR_LIST      0x8D  /* 3G */
#define GTP_EXT_TRIGGER_ID    0x8E  /* 3G */
#define GTP_EXT_OMC_ID        0x8F  /* 3G */
#define GTP_EXT_C1            0xC1
#define GTP_EXT_C2            0xC2
#define GTP_EXT_REL_PACK      0xF9  /* charging */
#define GTP_EXT_CAN_PACK      0xFA  /* charging */
#define GTP_EXT_CHRG_ADDR     0xFB
#define GTP_EXT_DATA_REQ      0xFC  /* charging */
#define GTP_EXT_DATA_RESP     0xFD  /* charging */
#define GTP_EXT_NODE_ADDR     0xFE  /* charging */
#define GTP_EXT_PRIV_EXT      0xFF

static const value_string gtp_val[] = {
      { GTP_EXT_CAUSE,  "Cause of operation" },
      { GTP_EXT_IMSI,         "IMSI" },
      { GTP_EXT_RAI,          "Routing Area Identity" },
      { GTP_EXT_TLLI,         "Temporary Logical Link Identity" },
      { GTP_EXT_PTMSI,  "Packet TMSI" },
      { GTP_EXT_QOS_GPRS,     "Quality of Service" },
      { GTP_EXT_REORDER,      "Reorder required" },
      { GTP_EXT_AUTH_TRI,     "Authentication triplets" },
      { GTP_EXT_MAP_CAUSE,    "MAP cause" },
      { GTP_EXT_PTMSI_SIG,    "P-TMSI signature" },
      { GTP_EXT_MS_VALID,     "MS validated" },
      { GTP_EXT_RECOVER,      "Recovery" },
      { GTP_EXT_SEL_MODE,     "Selection mode" },

      { GTP_EXT_16,           "Flow label data I" },
      { GTP_EXT_FLOW_LABEL,   "Flow label data I" },
      { GTP_EXT_TEID,         "Tunnel Endpoint Identifier Data I" },          /* 3G */

      { GTP_EXT_17,           "Flow label signalling" },
      { GTP_EXT_FLOW_SIG,     "Flow label signalling" },
      { GTP_EXT_TEID_CP,      "Tunnel Endpoint Identifier Data Control Plane" },    /* 3G */

      { GTP_EXT_18,           "Flow label data II" },
      { GTP_EXT_FLOW_II,      "Flow label data II" },
      { GTP_EXT_TEID_II,      "Tunnel Endpoint Identifier Data II" },         /* 3G */

      { GTP_EXT_19,           "MS not reachable reason" },
      { GTP_EXT_MS_REASON,    "MS not reachable reason" },
      { GTP_EXT_TEAR_IND,     "Teardown ID" },                          /* 3G */

      { GTP_EXT_NSAPI,  "NSAPI" },                                /* 3G */
      { GTP_EXT_RANAP_CAUSE,  "RANAP cause" },                          /* 3G */
      { GTP_EXT_RAB_CNTXT,    "RAB context" },                          /* 3G */
      { GTP_EXT_RP_SMS, "Radio Priority for MO SMS" },                  /* 3G */
      { GTP_EXT_RP,           "Radio Priority" },                             /* 3G */
      { GTP_EXT_PKT_FLOW_ID,  "Packet Flow ID" },                             /* 3G */
      { GTP_EXT_CHRG_CHAR,    "Charging characteristics" },                   /* 3G */
      { GTP_EXT_TRACE_REF,    "Trace references" },                           /* 3G */
      { GTP_EXT_TRACE_TYPE,   "Trace type" },                           /* 3G */
      { GTPv1_EXT_MS_REASON,  "MS not reachable reason" },                    /* 3G */
      { GTP_EXT_TR_COMM,      "Packet transfer command" },                    /* charging */
      { GTP_EXT_CHRG_ID,      "Charging ID" },
      { GTP_EXT_USER_ADDR,    "End user address" },
      { GTP_EXT_MM_CNTXT,     "MM context" },
      { GTP_EXT_PDP_CNTXT,    "PDP context" },
      { GTP_EXT_APN,          "Access Point Name" },
      { GTP_EXT_PROTO_CONF,   "Protocol configuration options" },
      { GTP_EXT_GSN_ADDR,     "GSN address" },
      { GTP_EXT_MSISDN, "MS international PSTN/ISDN number" },
      { GTP_EXT_QOS_UMTS,     "Quality of service (UMTS)" },                  /* 3G */
      { GTP_EXT_AUTH_QUI,     "Authentication quintuplets" },                 /* 3G */
      { GTP_EXT_TFT,          "Traffic Flow Template (TFT)" },                /* 3G */
      { GTP_EXT_TARGET_ID,    "Target (RNC) identification" },                /* 3G */
      { GTP_EXT_UTRAN_CONT,   "UTRAN transparent field" },                    /* 3G */
      { GTP_EXT_RAB_SETUP,    "RAB setup information" },                      /* 3G */
      { GTP_EXT_HDR_LIST,     "Extension Header Types List" },                /* 3G */
      { GTP_EXT_TRIGGER_ID,   "Trigger Id" },                           /* 3G */
      { GTP_EXT_OMC_ID, "OMC Identity" },                         /* 3G */
      { GTP_EXT_REL_PACK,     "Sequence numbers of released packets IE" },          /* charging */
      { GTP_EXT_CAN_PACK,     "Sequence numbers of canceled packets IE" },          /* charging */
      { GTP_EXT_CHRG_ADDR,    "Charging Gateway address" },
      { GTP_EXT_DATA_REQ,     "Data record packet" },                   /* charging */
      { GTP_EXT_DATA_RESP,    "Requests responded" },                   /* charging */
      { GTP_EXT_NODE_ADDR,    "Address of recommended node" },                /* charging */
      { GTP_EXT_PRIV_EXT,     "Private Extension" },
      { 0, NULL }
};

/* GPRS:    9.60 v7.6.0, page 37
 * UMTS:    29.060 v4.0, page 45
 */
static const value_string cause_type[] = {
      { 0,  "Request IMSI" },
      { 1,  "Request IMEI" },
      { 2,  "Request IMSI and IMEI" },
      { 3,  "No identity needed" },
      { 4,  "MS refuses" },
      { 5,  "MS is not GPRS responding" },
      { 59, "System failure" },     /* charging */
      { 60, "The transmit buffers are becoming full" },     /* charging */
      { 61, "The receive buffers are becoming full" },      /* charging */
      { 62, "Another node is about to go down" },     /* charging */
      { 63, "This node is about to go down" },  /* charging */
      { 128,      "Request accepted" },
      { 192,      "Non-existent" },
      { 193,      "Invalid message format" },
      { 194,      "IMSI not known" },
      { 195,      "MS is GPRS detached" },
      { 196,      "MS is not GPRS responding" },
      { 197,      "MS refuses" },
      { 198,      "Version not supported" },
      { 199,      "No resource available" },
      { 200,      "Service not supported" },
      { 201,      "Mandatory IE incorrect" },
      { 202,      "Mandatory IE missing" },
      { 203,      "Optional IE incorrect" },
      { 204,      "System failure" },
      { 205,      "Roaming restriction" },
      { 206,      "P-TMSI signature mismatch" },
      { 207,      "GPRS connection suspended" },
      { 208,      "Authentication failure" },
      { 209,      "User authentication failed" },
      { 210,      "Context not found" },
      { 211,      "All PDP dynamic addresses are occupied" },
      { 212,      "No memory is available" },
      { 213,      "Relocation failure" },
      { 214,      "Unknown mandatory extension header" },
      { 215,      "Semantic error in the TFT operation" },
      { 216,      "Syntactic error in the TFT operation" },
      { 217,      "Semantic errors in packet filter(s)" },
      { 218,      "Syntactic errors in packet filter(s)" },
      { 219,      "Missing or unknown APN" },
      { 220,      "Unknown PDP address or PDP type" },
      { 252,      "Request related to possibly duplicated packets already fulfilled" },   /* charging */
      { 253,      "Request already fulfilled" },      /* charging */
      { 254,      "Sequence numbers of released/cancelled packets IE incorrect" },  /* charging */
      { 255,      "Request not fulfilled" },    /* charging */
      { 0, NULL }
};

/* GPRS:    9.02 v7.7.0
 * UMTS:    29.002 v4.2.1, chapter 17.5, page 268
 * TODO: Check if all map_cause values are included
 */
static const value_string map_cause_type[] = {
      { 1, "Unknown subscriber" },
      { 8, "Roaming not allowed" },
      { 10, "Bearer service not provisioned" },
      { 11, "Teleservice not provisioned" },
      { 13, "Call barred" },
      { 21, "Facility not supported" },
      { 23, "Update GPRS location" },
      { 24, "Send routing info for GPRS" },
      { 26, "Note MS present for GPRS" },
      { 27, "Absent subscriber" },
      { 34, "System failure" },
      { 35, "Data missing" },
      { 36, "Unexpected data value" },
      { 44, "Number chenged" },
      { 45, "Busy subscriber" },
      { 46, "No subscriber reply" },
      { 48, "Facility not allowed" },
      { 0, NULL }
};

static const value_string gsn_addr_type[] = {
      { 0x00, "IPv4" },
      { 0x01, "IPv6" },
      { 0,  NULL },
};

static const value_string pdp_type[] = {
      { 0x00, "X.25" },
      { 0x01, "PPP" },
      { 0x02, "OSP:IHOSS" },
      { 0x21, "IPv4" },
      { 0x57, "IPv6" },
      { 0, NULL }
};

static const value_string pdp_org_type[] = {
      { 0, "ETSI" },
      { 1, "IETF" },
      { 0, NULL }
};

static const value_string qos_delay_type[] = {
      { 0x00, "Subsribed delay class (in MS to network direction)" },
      { 0x01, "Delay class 1" },
      { 0x02, "Delay class 2" },
      { 0x03, "Delay class 3" },
      { 0x04, "Delay class 4 (best effort)" },
      { 0x07,     "Reserved" },
      { 0, NULL }
};

static const value_string qos_reliability_type[] = {
      { 0x00, "Subscribed reliability class (in MS to network direction)" },
      { 0x01, "Ack GTP/LLC/RLC, Protected data" },
      { 0x02, "Unack GTP, Ack LLC/RLC, Protected data" },
      { 0x03, "Unack GTP/LLC, Ack RLC, Protected data" },
      { 0x04, "Unack GTP/LLC/RLC, Protected data" },
      { 0x05, "Unack GTP/LLC/RLC, Unprotected data" },
      { 0x07, "Reserved" },
      { 0, NULL }
};

static const value_string qos_peak_type[] = {
      { 0x00, "Subscribed peak throughput (in MS to network direction)" },
      { 0x01, "Up to 1 000 oct/s" },
      { 0x02, "Up to 2 000 oct/s" },
      { 0x03, "Up to 4 000 oct/s" },
      { 0x04, "Up to 8 000 oct/s" },
      { 0x05, "Up to 16 000 oct/s" },
      { 0x06, "Up to 32 000 oct/s" },
      { 0x07, "Up to 64 000 oct/s" },
      { 0x08, "Up to 128 000 oct/s" },
      { 0x09, "Up to 256 000 oct/s" },
/* QoS Peak throughput classes from 0x0A to 0x0F (from 10 to 15) are subscribed */
      { 0x0A,     "Reserved" },
      { 0x0B,     "Reserved" },
      { 0x0C,     "Reserved" },
      { 0x0D,     "Reserved" },
      { 0x0E,     "Reserved" },
      { 0x0F,     "Reserved" },
      { 0, NULL }
};

static const value_string qos_precedence_type[] = {
      { 0x00, "Subscribed precedence (in MS to network direction)" },
      { 0x01, "High priority" },
      { 0x02, "Normal priority" },
      { 0x03, "Low priority" },
      { 0x07, "Reserved" },
      { 0, NULL }
};

static const value_string qos_mean_type[] = {
      { 0x00, "Subscribed mean throughput (in MS to network direction)" },
      { 0x01, "100 oct/h" },        /* Class 2 */
      { 0x02, "200 oct/h" },        /* Class 3 */
      { 0x03, "500 oct/h" },        /* Class 4 */
      { 0x04, "1 000 oct/h" },      /* Class 5 */
      { 0x05, "2 000 oct/h" },      /* Class 6 */
      { 0x06, "5 000 oct/h" },      /* Class 7 */
      { 0x07, "10 000 oct/h" },     /* Class 8 */
      { 0x08, "20 000 oct/h" },     /* Class 9 */
      { 0x09, "50 000 oct/h" },     /* Class 10 */
      { 0x0A, "100 000 oct/h" },    /* Class 11 */
      { 0x0B, "200 000 oct/h" },    /* Class 12 */
      { 0x0C, "500 000 oct/h" },    /* Class 13 */
      { 0x0D, "1 000 000 oct/h" },  /* Class 14 */
      { 0x0E, "2 000 000 oct/h" },  /* Class 15 */
      { 0x0F, "5 000 000 oct/h" },  /* Class 16 */
      { 0x10, "10 000 000 oct/h" }, /* Class 17 */
      { 0x11, "20 000 000 oct/h" }, /* Class 18 */
      { 0x12, "50 000 000 oct/h" }, /* Class 19 */
/* QoS Mean throughput classes from 0x13 to 0x1E (from 19 to 30) are subscribed */
      { 0x13, "Reserved" },
      { 0x14, "Reserved" },
      { 0x15, "Reserved" },
      { 0x16, "Reserved" },
      { 0x17, "Reserved" },
      { 0x18, "Reserved" },
      { 0x19, "Reserved" },
      { 0x1A, "Reserved" },
      { 0x1B, "Reserved" },
      { 0x1C, "Reserved" },
      { 0x1D, "Reserved" },
      { 0x1E, "Reserved" },
      { 0x1F, "Best effort" },      /* Class 1 */
      { 0, NULL }
};

static const value_string qos_del_err_sdu[] = {
      { 0x00, "Subscribed delivery of erroneous SDUs (in MS to network direction)" },
      { 0x01, "No detect ('-')" },
      { 0x02, "Erroneous SDUs are delivered ('yes')" },
      { 0x03, "Erroneous SDUs are not delivered ('no')" },
      { 0x07, "Reserved" },         /* All other values are reserved */
      { 0, NULL }
};

static const value_string qos_del_order[] = {
      { 0x00, "Subscribed delivery order (in MS to network direction)" },
      { 0x01, "With delivery order ('yes')" },
      { 0x02, "Without delivery order ('no')" },
      { 0x03, "Reserved" },         /* All other values are reserved */
      { 0, NULL }
};

static const value_string qos_traf_class[] = {
      { 0x00, "Subscribed traffic class (in MS to network direction)" },
      { 0x01, "Conversational class" },
      { 0x02, "Streaming class" },
      { 0x03, "Interactive class" },
      { 0x04, "Background class" },
      { 0x07, "Reserved" },         /* All other values are reserved */
      { 0, NULL }
};

static const value_string qos_max_sdu_size[] = {
      { 0x00, "Subscribed maximum SDU size (in MS to network direction" },
      /* For values from 0x01 to 0x96 (from 1 to 150), use a granularity of 10 octets */
      { 0x97, "1502 octets" },
      { 0x98, "1510 octets" },
      { 0x99, "1520 octets" },
      { 0, NULL }                         /* All other values are reserved */
};

static const value_string qos_max_ul[] = {
      { 0x00, "Subscribed maximum bit rate for uplink (in MS to network direction)" },
      /* For values from 0x01 to 0x3F (from 1 to 63), use a granularity of 1 kbps */
      /* For values from 0x40 to 0x7F, value = 64 kbps + (value - 0x40) * 8 kbps */
      /* For values from 0x80 to 0xFE, value = 576 kbps + (value - 0x80) * 64 kbps */
      { 0xFF, "0 kbps" },
      { 0, NULL }
};

static const value_string qos_max_dl[] = {
      { 0x00, "Subscribed maximum bit rate for downlink (in MS to network direction)" },
      /* For values from 0x01 to 0x3F (from 1 to 63), use a granularity of 1 kbps */
      /* For values from 0x40 to 0x7F, value = 64 kbps + (value - 0x40) * 8 kbps */
      /* For values from 0x80 to 0xFE, value = 576 kbps + (value - 0x80) * 64 kbps */
      { 0xFF, "0 kbps" },
      { 0, NULL }
};

static const value_string qos_res_ber[] = {
      { 0x00, "Subscribed residual BER (in MS to network direction)" },
      { 0x01, "1/20 = 5x10^-2" },
      { 0x02, "1/100 = 1x10^-2" },
      { 0x03, "1/200 = 5x10^-3" },
      { 0x04, "1/250 = 4x10^-3" },
      { 0x05, "1/1 000 = 1x10^-3" },
      { 0x06, "1/10 000 = 1x10^-4" },
      { 0x07, "1/100 000 = 1x10^-5" },
      { 0x08, "1/1 000 000 = 1x10^-6" },
      { 0x09, "3/50 000 000 = 6x10^-8" },
      { 0x0F, "Reserved" },         /* All other values are reserved */
      { 0, NULL }
};

static const value_string qos_sdu_err_ratio[] = {
      { 0x00, "Subscribed SDU error ratio (in MS to network direction)" },
      { 0x01, "1/100 = 1x10^-2" },
      { 0x02, "7/1000 = 7x10^-3" },
      { 0x03, "1/1 000 = 1x10^-3" },
      { 0x04, "1/10 000 = 1x10^-4" },
      { 0x05, "1/100 000 = 1x10^-5" },
      { 0x06, "1/1 000 000 = 1x10^-6" },
      { 0x07, "1/10 = 1x10^-1" },
      { 0x0F, "Reserved" },         /* All other values are reserved */
      { 0, NULL }
};

static const value_string qos_traf_handl_prio[] = {
      { 0x00, "Subscribed traffic handling priority (in MS to network direction)" },
      { 0x01, "Priority level 1" },
      { 0x02, "Priority level 2" },
      { 0x03, "Priority level 3" },
      { 0, NULL }
};

static const value_string qos_trans_delay[] = {
      { 0x00, "Subscribed Transfer Delay (in MS to network direction)" },
      { 0x01, "10 ms" },      /* Using a granularity of 10 ms */
      { 0x02, "20 ms" },
      { 0x03, "30 ms" },
      { 0x04, "40 ms" },
      { 0x05, "50 ms" },
      { 0x06, "60 ms" },
      { 0x07, "70 ms" },
      { 0x08, "80 ms" },
      { 0x09, "90 ms" },
      { 0x0A, "100 ms" },
      { 0x0B, "110 ms" },
      { 0x0C, "120 ms" },
      { 0x0D, "130 ms" },
      { 0x0E, "140 ms" },
      { 0x0F, "150 ms" },
      { 0x10, "200 ms" },     /* (For values from 0x10 to 0x1F, value = 200 ms + (value - 0x10) * 50 ms */
      { 0x11, "250 ms" },
      { 0x12, "300 ms" },
      { 0x13, "350 ms" },
      { 0x14, "400 ms" },
      { 0x15, "450 ms" },
      { 0x16, "500 ms" },
      { 0x17, "550 ms" },
      { 0x18, "600 ms" },
      { 0x19, "650 ms" },
      { 0x1A, "700 ms" },
      { 0x1B, "750 ms" },
      { 0x1C, "800 ms" },
      { 0x1D, "850 ms" },
      { 0x1E, "900 ms" },
      { 0x1F, "950 ms" },
      { 0x20, "1000 ms" },    /* For values from 0x20 to 0x3E, value = 1000 ms + (value - 0x20) * 100 ms */
      { 0x21, "1100 ms" },
      { 0x22, "1200 ms" },
      { 0x23, "1300 ms" },
      { 0x24, "1400 ms" },
      { 0x25, "1500 ms" },
      { 0x26, "1600 ms" },
      { 0x27, "1700 ms" },
      { 0x28, "1800 ms" },
      { 0x29, "1900 ms" },
      { 0x2A, "2000 ms" },
      { 0x2B, "2100 ms" },
      { 0x2C, "2200 ms" },
      { 0x2D, "2300 ms" },
      { 0x2E, "2400 ms" },
      { 0x2F, "2500 ms" },
      { 0x30, "2600 ms" },
      { 0x31, "2700 ms" },
      { 0x32, "2800 ms" },
      { 0x33, "2900 ms" },
      { 0x34, "3000 ms" },
      { 0x35, "3100 ms" },
      { 0x36, "3200 ms" },
      { 0x37, "3300 ms" },
      { 0x38, "3400 ms" },
      { 0x39, "3500 ms" },
      { 0x3A, "3600 ms" },
      { 0x3B, "3700 ms" },
      { 0x3C, "3800 ms" },
      { 0x3D, "3900 ms" },
      { 0x3E, "4000 ms" },
      { 0x3F, "Reserved"},
      { 0, NULL }
};

static const value_string qos_guar_ul[] = {
      { 0x00, "Subscribed guaranteed bit rate for uplink (in MS to network direction)" },
      /* For values from 0x01 to 0x3F (from 1 to 63), use a granularity of 1 kbps */
      /* For values from 0x40 to 0x7F, value = 64 kbps + (value - 0x40) * 8 kbps */
      /* For values from 0x80 to 0xFE, value = 576 kbps + (value - 0x80) * 64 kbps */
      { 0xFF, "0 kbps" },
      { 0, NULL }
};

static const value_string qos_guar_dl[] = {
      { 0x00, "Subscribed guaranteed bit rate for downlink (in MS to network direction)" },
      /* For values from 0x01 to 0x3F (from 1 to 63), use a granularity of 1 kbps */
      /* For values from 0x40 to 0x7F, value = 64 kbps + (value - 0x40) * 8 kbps */
      /* For values from 0x80 to 0xFE, value = 576 kbps + (value - 0x80) * 64 kbps */
      { 0xFF, "0 kbps" },
      { 0, NULL }
};

static const value_string sel_mode_type[] = {
      { 0,  "MS or network provided APN, subscribed verified" },
      { 1,  "MS provided APN, subscription not verified" },
      { 2,  "Network provided APN, subscription not verified" },
      { 3,  "For future use (Network provided APN, subscription not verified" },/* Shall not be sent. If received, shall be sent as value 2 */
      { 0,  NULL }
};

static const value_string tr_comm_type[] = {
      { 1,  "Send data record packet" },
      { 2,  "Send possibly duplicated data record packet" },
      { 3,  "Cancel data record packet" },
      { 4,  "Release data record packet"},
      { 0,  NULL }
};

/* TODO: CHeck if all ms_reasons are included */
static const value_string ms_not_reachable_type[] = {
      { 0,  "No paging response via the MSC" },
      { 1,  "IMSI detached" },
      { 2,  "Roaming restriction" },
      { 3,  "Deregistered in the HLR for non GPRS" },
      { 4,  "MS purge for non GPRS" },
      { 5,  "No paging response via the SGSN" },
      { 6,  "GPRS detached" },
      { 7,  "Deregistered in the HLR for non GPRS" },
      { 8,  "MS purged for GPRS" },
      { 9,  "Unidentified subscriber via the MSC" },
      { 10, "Unidentified subscriber via the SGSN" },
      { 0,  NULL }
};

/* UMTS:    25.413 v3.4.0, chapter 9.2.1.4, page 80
 */
static const value_string ranap_cause_type[] = {
/* Radio Network Layer Cause (1-->64) */
      { 1, "RAB preempted" },
      { 2, "Trelocoverall Expiry" },
      { 3, "Trelocprep Expiry" },
      { 4, "Treloccomplete Expiry" },
      { 5, "Tqueing Expiry" },
      { 6, "Relocation Triggered" },
      { 7, "TRELOCalloc Expiry" },
      { 8, "Unable to Estabish During Relocation" },
      { 9, "Unknown Target RNC" },
      { 10, "Relocation Cancelled" },
      { 11, "Successful Relocation" },
      { 12, "Requested Ciphering and/or Integrity Protection Algorithms not Supported" },
      { 13, "Change of Ciphering and/or Integrity Protection is not supported" },
      { 14, "Failure in the Radio Interface Procedure" },
      { 15, "Release due to UTRAN Generated Reason" },
      { 16, "User Inactivity" },
      { 17, "Time Critical Relocation" },
      { 18, "Requested Traffic Class not Available" },
      { 19, "Invalid RAB Parameters Value" },
      { 20, "Requested Maximum Bit Rate not Available" },
      { 21, "Requested Guaranteed Bit Rate not Available" },
      { 22, "Requested Transfer Delay not Achievable" },
      { 23, "Invalid RAB Parameters Combination" },
      { 24, "Condition Violation for SDU Parameters" },
      { 25, "Condition Violation for Traffic Handling Priority" },
      { 26, "Condition Violation for Guaranteed Bit Rate" },
      { 27, "User Plane Versions not Supported" },
      { 28, "Iu UP Failure" },
      { 29, "Relocation Failure in Target CN/RNC or Target System" },
      { 30, "Invalid RAB ID" },
      { 31, "No Remaining RAB" },
      { 32, "Interaction with other procedure" },
      { 33, "Requested Maximum Bit Rate for DL not Available" },
      { 34, "Requested Maximum Bit Rate for UL not Available" },
      { 35, "Requested Guaranteed Bit Rate for DL not Available" },
      { 36, "Requested Guaranteed Bit Rate for UL not Available" },
      { 37, "Repeated Integrity Checking Failure" },
      { 38, "Requested Report Type not supported" },
      { 39, "Request superseded" },
      { 40, "Release due to UE generated signalling connection release" },
      { 41, "Resource Optimisation Relocation" },
      { 42, "Requested Information Not Available" },
      { 43, "Relocation desirable for radio reasons" },
      { 44, "Relocation not supported in Target RNC or Target System" },
      { 45, "Directed Retry" },
      { 46, "Radio Connection With UE Lost" },
/* Transport Layer Cause (65-->80) */
      { 65, "Signalling Transport Resource Failure" },
      { 66, "Iu Transport Connection Failed to Establish" },
/* NAS Cause (81-->96) */
      { 81, "User Restriction Start Indication" },
      { 82, "User Restriction End Indication" },
      { 83, "Normal Release" },
/* Protocol Cause (97-->112) */
      { 97, "Transfer Syntax Error" },
      { 98, "Semantic Error" },
      { 99, "Message not compatible with receiver state" },
      { 100, "Abstract Syntax Error (Reject)" },
      { 101, "Abstract Syntax Error (Ignore and Notify)" },
      { 102, "Abstract Syntax Error (Falsely Constructed Message" },
/* Miscellaneous Cause (113-->128) */
      { 113, "O & M Intervention" },
      { 114, "No Resource Available" },
      { 115, "Unspecified Failure" },
      { 116, "Network Opimisation" },
/* Non-standard Cause (129-->255) */
      { 0, NULL }
};

static const value_string mm_sec_modep[] = {
      { 0,  "Used cipher value, UMTS keys and Quintuplets" },
      { 1,  "GSM key and triplets" },
      { 2,  "UMTS key and quintuplets" },
      { 3,  "GSM key and quintuplets" },
      { 0,  NULL }
};

#define MM_PROTO_GROUP_CALL_CONTROL 0x00
#define MM_PROTO_BROADCAST_CALL_CONTROL   0x01
#define MM_PROTO_PDSS1              0x02
#define MM_PROTO_CALL_CONTROL       0x03
#define MM_PROTO_PDSS2              0x04
#define MM_PROTO_MM_NON_GPRS        0x05
#define MM_PROTO_RR_MGMT            0x06
#define MM_PROTO_MM_GPRS            0x08
#define MM_PROTO_SMS                0x09
#define MM_PROTO_SESSION_MGMT       0x0A
#define MM_PROTO_NON_CALL_RELATED   0x0B

static const value_string mm_proto_disc[] = {
      { MM_PROTO_GROUP_CALL_CONTROL,            "Group call control" },
      { MM_PROTO_BROADCAST_CALL_CONTROL,  "Broadcast call control" },
      { MM_PROTO_PDSS1,             "PDSS1" },
      { MM_PROTO_CALL_CONTROL,            "Call control; call related SS messages" },
      { MM_PROTO_PDSS2,             "PDSS2" },
      { MM_PROTO_MM_NON_GPRS,             "Mobility Management messages for non-GPRS services" },
      { MM_PROTO_RR_MGMT,                 "Radio Resource management messages" },
      { MM_PROTO_MM_GPRS,                 "Mobility Management messages for GPRS services" },
      { MM_PROTO_SMS,                     "SMS" },
      { MM_PROTO_SESSION_MGMT,            "Session Management messages" },
      { MM_PROTO_NON_CALL_RELATED,        "Non-call related SS messages" },
      { 0,                          NULL }
};

static const value_string mm_rr_mess[] = {
      { 0x3C, "RR initialization request" },
      { 0x3B, "Additional assignment" },
      { 0x3F, "Immediate assignment" },
      { 0x39, "Immediate assignment extended" },
      { 0x3A, "Immediate assignment reject" },

      { 0x35, "Ciphering mode command" },
      { 0x32, "Ciphering mode complete" },

      { 0x30, "Configuration change command" },
      { 0x31, "Configuration change ack" },
      { 0x33, "Configuration change reject" },

      { 0x2E, "Assignment command" },
      { 0x29, "Assignment complete" },
      { 0x2F, "Assigment failure" },
      { 0x2B, "Handover command" },
      { 0x2C, "Handover complete" },
      { 0x28, "Handover failure" },
      { 0x2D, "Physical information" },

      { 0x08, "RR-cell change order" },
      { 0x23, "PDCH assignment command" },

      { 0x0D, "Channel release" },
      { 0x0A, "Partial release" },
      { 0x0F, "PArtial release complete" },

      { 0x21, "Paging request type 1" },
      { 0x22, "Paging request type 2" },
      { 0x24, "Paging request type 3" },
      { 0x27, "Paging response" },
      { 0x20, "Notification/NCH" },
      { 0x25, "Notification/FACCH" },
      { 0x26, "Reserved" },
      { 0x0B, "Reserved" },

      { 0x18, "System information type 8" },
      { 0x19, "System information type 1" },
      { 0x1A, "System information type 2" },
      { 0x1B, "System information type 3" },
      { 0x1C, "System information type 4" },
      { 0x1D, "System information type 5" },
      { 0x1E, "System information type 6" },
      { 0x1F, "System information type 7" },

      { 0x02, "System information type 2bis" },
      { 0x03, "System information type 2ter" },
      { 0x05, "System information type 5bis" },
      { 0x06, "System information type 5ter" },
      { 0x04, "System information 9" },
      { 0x00, "System information 13" },
      { 0x01, "System information 14" },

      { 0x3D, "System information type 16" },
      { 0x3E, "System information type 17" },

      { 0x10, "Channel mode modify" },
      { 0x12, "RR status" },
      { 0x17, "Channel mode modify ack" },
      { 0x14, "Frequency redefinition" },
      { 0x15, "Measurement report" },
      { 0x16, "Classmark change" },
      { 0x13, "Classmark enquiry" },
      { 0x36, "Extended measurement report" },
      { 0x37, "Extended measurement order" },
      { 0x34, "GPRS suspension request" },

      { 0x09, "VGCS uplink grant" },
      { 0x0E, "Uplink release" },
      { 0x0C, "Uplink free" },
      { 0x2A, "Uplink busy" },
      { 0x11, "Talker indication" },

      { 0, NULL }
};

static const value_string mm_mm_mess[] = {
      { 0x01, "IMSI DETACH INDICATION" },
      { 0x02, "LOCATION UPDATING ACCEPT" },
      { 0x04, "LOCATION UPDATING REJECT" },
      { 0x08, "LOCATION UPDATING REQUEST" },
      { 0x11, "AUTHENTICATION REJECT" },
      { 0x12, "AUTHENTICATION REQUEST" },
      { 0x14, "AUTHENTICATION RESPONSE" },
      { 0x18, "IDENTITY REQUEST" },
      { 0x19, "IDENTITY RESPONSE" },
      { 0x1A, "TMSI REALLOCATION COMMAND" },
      { 0x1B, "TMSI REALLOCATION COMPLETE" },
      { 0x21, "CM SERVICE ACCEPT" },
      { 0x22, "CM SERVICE REJECT" },
      { 0x23, "CM SERVICE ABORT" },
      { 0x24, "CM SERVICE REQUEST" },
      { 0x25, "CM SERVICE PROMPT" },
      { 0x26, "NOTIFICATION RESPONSE" },
      { 0x28, "CM RE-ESTABLISHMENT REQUEST" },
      { 0x29, "ABORT" },
      { 0x30, "MM NULL" },
      { 0x31, "MM STATUS" },
      { 0x32, "MM INFORMATION" },
      { 0, NULL }
};

static const value_string mm_cc_mess[] = {
      { 0x00, "escape to nationally specific" },
/*{ 0 x 0 0, "- - - Call establishment messages:" },*/
      { 0x01, "ALERTING" },
      { 0x08, "CALL CONFIRMED" },
      { 0x02, "CALL PROCEEDING" },
      { 0x07, "CONNECT" },
      { 0x0F, "CONNECT ACKNOWLEDGE" },
      { 0x0E, "EMERGENCY SETUP" },
      { 0x03, "PROGRESS" },
      { 0x04, "CC-ESTABLISHMENT" },
      { 0x06, "CC-ESTABLISHMENT CONFIRMED" },
      { 0x0B, "RECALL" },
      { 0x09, "START CC" },
      { 0x05, "SETUP" },
/*{ 0 x 0 1, "- - - Call information phase messages:" },*/
      { 0x17, "MODIFY" },
      { 0x1F, "MODIFY COMPLETE" },
      { 0x13, "MODIFY REJECT" },
      { 0x10, "USER INFORMATION" },
      { 0x18, "HOLD" },
      { 0x19, "HOLD ACKNOWLEDGE" },
      { 0x1A, "HOLD REJECT" },
      { 0x1C, "RETRIEVE" },
      { 0x1D, "RETRIEVE ACKNOWLEDGE" },
      { 0x1E, "RETRIEVE REJECT" },
/*{ 0 x 1 0, "- - - Call clearing messages:" },*/
      { 0x25, "DISCONNECT" },
      { 0x2D, "RELEASE" },
      { 0x2A, "RELEASE COMPLETE" },
/*{ 0 x 1 1, "- - - Miscellaneous messages:" },*/
      { 0x39, "CONGESTION CONTROL" },
      { 0x3E, "NOTIFY" },
      { 0x3D, "STATUS" },
      { 0x34, "STATUS ENQUIRY" },
      { 0x35, "START DTMF" },
      { 0x31, "STOP DTMF" },
      { 0x32, "STOP DTMF ACKNOWLEDGE" },
      { 0x36, "START DTMF ACKNOWLEDGE" },
      { 0x37, "START DTMF REJECT" },
      { 0x3A, "FACILITY" },
      { 0, NULL }
};

static const value_string mm_gprs_mess[] = {
      { 0x01, "Attach request" },
      { 0x02, "Attach accept" },
      { 0x03, "Attach complete" },
      { 0x04, "Attach reject" },
      { 0x05, "Detach request" },
      { 0x06, "Detach accept" },
      { 0x08, "Routing area update request" },
      { 0x09, "Routing area update accept" },
      { 0x0A, "Routing area update complete" },
      { 0x0B, "Routing area update reject" },
      { 0x10, "P-TMSI reallocation command" },
      { 0x11, "P-TMSI reallocation complete" },
      { 0x12, "Authentication and ciphering req" },
      { 0x13, "Authentication and ciphering resp" },
      { 0x14, "Authentication and ciphering rej" },
      { 0x15, "Identity request" },
      { 0x16, "Identity response" },
      { 0x20, "GMM status" },
      { 0x21, "GMM information" },
      { 0, NULL }
};

static const value_string tft_code_type[] = {
      { 0, "Spare" },
      { 1, "Create new TFT" },
      { 2, "Delete existing TFT" },
      { 3, "Add packet filters to existing TFT" },
      { 4, "Replace packet filters in existing TFT" },
      { 5, "Delete packet filters from existing TFT" },
      { 6, "Reserved" },
      { 7, "Reserved" },
      { 0, NULL }
};


static dissector_handle_t ip_handle;
static dissector_handle_t ipv6_handle;
static dissector_handle_t ppp_handle;
static dissector_handle_t data_handle;
static dissector_handle_t gtpcdr_handle;

static int decode_gtp_cause         (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_imsi          (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_rai           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_tlli          (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_ptmsi         (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_qos_gprs            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_reorder       (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_auth_tri            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_map_cause           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_ptmsi_sig           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_ms_valid            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_recovery            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_sel_mode            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_16            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_17            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_18            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_19            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_nsapi         (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_ranap_cause   (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_rab_cntxt           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_rp_sms        (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_rp            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_pkt_flow_id   (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_chrg_char           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_trace_ref           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_trace_type    (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_ms_reason           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_tr_comm       (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_chrg_id       (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_user_addr           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_mm_cntxt            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_pdp_cntxt           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_apn           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_gsn_addr            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_proto_conf    (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_msisdn        (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_qos_umts            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_auth_qui            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_tft           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_target_id           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_utran_cont    (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_rab_setup           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_hdr_list            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_trigger_id    (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_omc_id        (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_chrg_addr           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_rel_pack            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_can_pack            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_data_req            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_data_resp           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_node_addr           (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_priv_ext            (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
static int decode_gtp_unknown       (tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);

typedef struct _gtp_opt {
      int   optcode;
      int  (*decode)(tvbuff_t  *, int, packet_info *, proto_tree *);
} gtp_opt_t;

static const gtp_opt_t gtpopt[] = {
      { GTP_EXT_CAUSE,  decode_gtp_cause },
      { GTP_EXT_IMSI,         decode_gtp_imsi },
      { GTP_EXT_RAI,          decode_gtp_rai },
      { GTP_EXT_TLLI,         decode_gtp_tlli },
      { GTP_EXT_PTMSI,  decode_gtp_ptmsi },
      { GTP_EXT_QOS_GPRS,     decode_gtp_qos_gprs },
      { GTP_EXT_REORDER,      decode_gtp_reorder },
      { GTP_EXT_AUTH_TRI,     decode_gtp_auth_tri },
      { GTP_EXT_MAP_CAUSE,    decode_gtp_map_cause },
      { GTP_EXT_PTMSI_SIG,    decode_gtp_ptmsi_sig },
      { GTP_EXT_MS_VALID,     decode_gtp_ms_valid },
      { GTP_EXT_RECOVER,      decode_gtp_recovery },
      { GTP_EXT_SEL_MODE,     decode_gtp_sel_mode },
      { GTP_EXT_16,           decode_gtp_16 },
      { GTP_EXT_17,           decode_gtp_17 },
      { GTP_EXT_18,           decode_gtp_18 },
      { GTP_EXT_19,           decode_gtp_19 },
      { GTP_EXT_NSAPI,  decode_gtp_nsapi },
      { GTP_EXT_RANAP_CAUSE,  decode_gtp_ranap_cause },
      { GTP_EXT_RAB_CNTXT,    decode_gtp_rab_cntxt },
      { GTP_EXT_RP_SMS, decode_gtp_rp_sms },
      { GTP_EXT_RP,           decode_gtp_rp },
      { GTP_EXT_PKT_FLOW_ID,  decode_gtp_pkt_flow_id },
      { GTP_EXT_CHRG_CHAR,    decode_gtp_chrg_char },
      { GTP_EXT_TRACE_REF,    decode_gtp_trace_ref },
      { GTP_EXT_TRACE_TYPE,   decode_gtp_trace_type },
      { GTPv1_EXT_MS_REASON,  decode_gtp_ms_reason },
      { GTP_EXT_TR_COMM,      decode_gtp_tr_comm },
      { GTP_EXT_CHRG_ID,      decode_gtp_chrg_id },
      { GTP_EXT_USER_ADDR,    decode_gtp_user_addr },
      { GTP_EXT_MM_CNTXT,     decode_gtp_mm_cntxt },
      { GTP_EXT_PDP_CNTXT,    decode_gtp_pdp_cntxt },
      { GTP_EXT_APN,          decode_gtp_apn },
      { GTP_EXT_PROTO_CONF,   decode_gtp_proto_conf },
      { GTP_EXT_GSN_ADDR,     decode_gtp_gsn_addr },
      { GTP_EXT_MSISDN, decode_gtp_msisdn },
      { GTP_EXT_QOS_UMTS,     decode_gtp_qos_umts },                    /* 3G */
      { GTP_EXT_AUTH_QUI,     decode_gtp_auth_qui },                    /* 3G */
      { GTP_EXT_TFT,          decode_gtp_tft },                   /* 3G */
      { GTP_EXT_TARGET_ID,    decode_gtp_target_id },             /* 3G */
      { GTP_EXT_UTRAN_CONT,   decode_gtp_utran_cont },                  /* 3G */
      { GTP_EXT_RAB_SETUP,    decode_gtp_rab_setup },             /* 3G */
      { GTP_EXT_HDR_LIST,     decode_gtp_hdr_list },                    /* 3G */
      { GTP_EXT_TRIGGER_ID,   decode_gtp_trigger_id },                  /* 3G */
      { GTP_EXT_OMC_ID, decode_gtp_omc_id },                      /* 3G */
      { GTP_EXT_REL_PACK,     decode_gtp_rel_pack },                    /* charging */
      { GTP_EXT_CAN_PACK,     decode_gtp_can_pack },              /* charging */
      { GTP_EXT_CHRG_ADDR,    decode_gtp_chrg_addr },
      { GTP_EXT_DATA_REQ,     decode_gtp_data_req },                    /* charging */
      { GTP_EXT_DATA_RESP,    decode_gtp_data_resp },             /* charging */
      { GTP_EXT_NODE_ADDR,    decode_gtp_node_addr },
      { GTP_EXT_PRIV_EXT,     decode_gtp_priv_ext },
      { 0,              decode_gtp_unknown }
};

struct _gtp_hdr {
      guint8            flags;
      guint8            message;
      guint16           length;
};

static      guint8            gtp_version = 0;
static      char        *yesno[] = { "no", "yes" };

static void
col_append_str_gtp(column_info *cinfo, gint el, gchar *proto_name) {

      int   i;
      int   max_len;
      gchar _tmp[COL_MAX_LEN];

      max_len = COL_MAX_LEN;

      for (i = 0; i < cinfo->num_cols; i++) {
            if (cinfo->fmt_matx[i][el]) {
                  if (cinfo->col_data[i] != cinfo->col_buf[i]) {

                        strncpy(cinfo->col_buf[i], cinfo->col_data[i], max_len);
                        cinfo->col_buf[i][max_len - 1] = '\0';
                        }

                  _tmp[0] = '\0';
                  strcat(_tmp, proto_name);
                  strcat(_tmp, " <");
                  strcat(_tmp, cinfo->col_buf[i]);
                  strcat(_tmp, ">");
                  cinfo->col_buf[i][0] = '\0';
                  strcat(cinfo->col_buf[i], _tmp);
                  cinfo->col_data[i] = cinfo->col_buf[i];
            }
      }
}

static gchar *
id_to_str(const guint8 *ad) {

      static gchar      str[17] = "                ";
      guint8            bits8to5, bits4to1;
      int         i, j = 0;
      static const      gchar hex_digits[10] = "0123456789";

      for (i = 0; i < 8; i++) {
            bits8to5 = (ad[i] >> 4) & 0x0F;
            bits4to1 = ad[i] & 0x0F;
            if (bits8to5 < 0xA) 
                  str[j++] = hex_digits[bits4to1];
            if (bits4to1 < 0xA) 
                  str[j++] = hex_digits[bits8to5];
      }
      str[j] = '\0';
      return str;
}

static gchar *
imsi_to_str(const guint8 *ad) {

      static gchar      str[17] = "                ";
      int         i, j = 0;

      for (i = 0; i < 8; i++) {
            if ((ad[i] & 0x0F) <= 9) str[j++] = (ad[i] & 0x0F) + 0x30;
            if (((ad[i] >> 4) & 0x0F) <= 9) str[j++] = ((ad[i] >> 4) & 0x0F) + 0x30;
      }
      str[j] = '\0';

      return str;
}

static gchar *
msisdn_to_str(const guint8 *ad, int len) {

      static gchar      str[18] = "+                ";
      guint8            bits8to5, bits4to1;
      int         i, j = 1;
      static const      gchar hex_digits[10] = "0123456789";

      for (i = 1; i < len && i < 9; i++) {
            bits8to5 = (ad[i] >> 4) & 0x0F;
            bits4to1 = ad[i] & 0x0F;
            if (bits4to1 < 0xA) 
                  str[j++] = hex_digits[bits4to1];
            if (bits8to5 < 0xA) 
                  str[j++] = hex_digits[bits8to5];
      }
      str[j] = '\0';
      
      return str;
}

/* Next definitions and function check_field_presence checks if given field
 * in GTP packet is compliant with ETSI
 */
typedef struct _header {
      guint8            code;
      guint8            presence;
} ext_header;

typedef struct _message {
      guint8            code;
      ext_header  fields[32];
} _gtp_mess_items;

/* ---------------------
 * GPRS messages
 * ---------------------*/
static _gtp_mess_items gprs_mess_items[] = {

{
      GTP_MSG_ECHO_REQ, {
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_ECHO_RESP, {
            { GTP_EXT_RECOVER,      GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_VER_NOT_SUPP, {
            { 0,              0 }
      }
},
{
      GTP_MSG_NODE_ALIVE_REQ, {
            { GTP_EXT_NODE_ADDR,    GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_NODE_ALIVE_RESP, {
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_REDIR_REQ, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_NODE_ADDR,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_REDIR_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_CREATE_PDP_REQ, {
            { GTP_EXT_QOS_GPRS,     GTP_MANDATORY },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_SEL_MODE,     GTP_MANDATORY },
            { GTP_EXT_FLOW_LABEL,   GTP_MANDATORY },
            { GTP_EXT_FLOW_SIG,     GTP_MANDATORY },
            { GTP_EXT_MSISDN, GTP_MANDATORY },
            { GTP_EXT_USER_ADDR,    GTP_MANDATORY },
            { GTP_EXT_APN,          GTP_MANDATORY },
            { GTP_EXT_PROTO_CONF,   GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_CREATE_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_QOS_GPRS,     GTP_CONDITIONAL },
            { GTP_EXT_REORDER,      GTP_CONDITIONAL },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_FLOW_LABEL,   GTP_CONDITIONAL },
            { GTP_EXT_FLOW_SIG,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ID,      GTP_CONDITIONAL },
            { GTP_EXT_USER_ADDR,    GTP_CONDITIONAL },
            { GTP_EXT_PROTO_CONF,   GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ADDR,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_UPDATE_PDP_REQ, {
            { GTP_EXT_QOS_GPRS,     GTP_MANDATORY },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_FLOW_LABEL,   GTP_MANDATORY },
            { GTP_EXT_FLOW_SIG,     GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 },
      }
},
{
      GTP_MSG_UPDATE_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_QOS_GPRS,     GTP_CONDITIONAL },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_FLOW_LABEL,   GTP_CONDITIONAL },
            { GTP_EXT_FLOW_SIG,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ID,      GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ADDR,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DELETE_PDP_REQ, {
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DELETE_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 },
      }
},
{
      GTP_MSG_CREATE_AA_PDP_REQ, {
            { GTP_EXT_QOS_GPRS,     GTP_MANDATORY },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_SEL_MODE,     GTP_MANDATORY },
            { GTP_EXT_FLOW_LABEL,   GTP_MANDATORY },
            { GTP_EXT_FLOW_SIG,     GTP_MANDATORY },
            { GTP_EXT_USER_ADDR,    GTP_MANDATORY },
            { GTP_EXT_APN,          GTP_MANDATORY },
            { GTP_EXT_PROTO_CONF,   GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_CREATE_AA_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_QOS_GPRS,     GTP_CONDITIONAL },
            { GTP_EXT_REORDER,      GTP_CONDITIONAL },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_FLOW_LABEL,   GTP_CONDITIONAL },
            { GTP_EXT_FLOW_SIG,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ID,      GTP_CONDITIONAL },
            { GTP_EXT_USER_ADDR,    GTP_CONDITIONAL },
            { GTP_EXT_PROTO_CONF,   GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ADDR,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DELETE_AA_PDP_REQ, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DELETE_AA_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_ERR_IND, {
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_REQ, {
            { GTP_EXT_USER_ADDR,    GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_REJ_REQ, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_USER_ADDR,    GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_REJ_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SEND_ROUT_INFO_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SEND_ROUT_INFO_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_MAP_CAUSE,    GTP_OPTIONAL },
            { GTP_EXT_MS_REASON,    GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FAIL_REP_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FAIL_REP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_MAP_CAUSE,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_MS_PRESENT_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_MS_PRESENT_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_IDENT_REQ, {
            { GTP_EXT_RAI,          GTP_MANDATORY },
            { GTP_EXT_PTMSI,  GTP_MANDATORY },
            { GTP_EXT_PTMSI_SIG,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_IDENT_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_AUTH_TRI,     GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SGSN_CNTXT_REQ, {
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_RAI,          GTP_MANDATORY },
            { GTP_EXT_TLLI,         GTP_MANDATORY },
            { GTP_EXT_PTMSI_SIG,    GTP_OPTIONAL },
            { GTP_EXT_MS_VALID,     GTP_OPTIONAL },
            { GTP_EXT_FLOW_SIG,     GTP_MANDATORY },
            { 0,              0 }
      }
},
{
      GTP_MSG_SGSN_CNTXT_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_FLOW_SIG,     GTP_CONDITIONAL },
            { GTP_EXT_MM_CNTXT,     GTP_CONDITIONAL },
            { GTP_EXT_PDP_CNTXT,    GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SGSN_CNTXT_ACK, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_FLOW_II,      GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DATA_TRANSF_REQ, {
            { GTP_EXT_TR_COMM,      GTP_MANDATORY },
            { GTP_EXT_DATA_REQ,     GTP_CONDITIONAL },
            { GTP_EXT_REL_PACK,     GTP_CONDITIONAL },
            { GTP_EXT_CAN_PACK,     GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DATA_TRANSF_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_DATA_RESP,    GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      0, {
            { 0,              0 }
      }
}
};

/* -----------------------------
 * UMTS messages
 * -----------------------------*/
static _gtp_mess_items umts_mess_items[] = {

{
      GTP_MSG_ECHO_REQ, {
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_ECHO_RESP, {
            { GTP_EXT_RECOVER,      GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_VER_NOT_SUPP, {
            { 0,              0 }
      }
},
{
      GTP_MSG_NODE_ALIVE_REQ, {
            { GTP_EXT_NODE_ADDR,    GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_NODE_ALIVE_RESP, {
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_REDIR_REQ, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_NODE_ADDR,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_REDIR_REQ, {
            { 0,              0 }
      }
},
{
      GTP_MSG_CREATE_PDP_REQ, {
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_SEL_MODE,     GTP_CONDITIONAL },
            { GTP_EXT_TEID,         GTP_MANDATORY },
            { GTP_EXT_TEID_CP,      GTP_CONDITIONAL },
            { GTP_EXT_NSAPI,  GTP_MANDATORY },
            { GTP_EXT_NSAPI,  GTP_CONDITIONAL },
            { GTP_EXT_CHRG_CHAR,    GTP_OPTIONAL },
            { GTP_EXT_TRACE_REF,    GTP_OPTIONAL },
            { GTP_EXT_TRACE_TYPE,   GTP_OPTIONAL },
            { GTP_EXT_USER_ADDR,    GTP_CONDITIONAL },
            { GTP_EXT_APN,          GTP_CONDITIONAL },
            { GTP_EXT_PROTO_CONF,   GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_MSISDN, GTP_CONDITIONAL },
            { GTP_EXT_QOS_UMTS,     GTP_MANDATORY },
            { GTP_EXT_TFT,          GTP_CONDITIONAL },
            { GTP_EXT_TRIGGER_ID,   GTP_OPTIONAL },
            { GTP_EXT_OMC_ID, GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_CREATE_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_REORDER,      GTP_CONDITIONAL },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_TEID,         GTP_CONDITIONAL },
            { GTP_EXT_TEID_CP,      GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ID,      GTP_CONDITIONAL },
            { GTP_EXT_USER_ADDR,    GTP_CONDITIONAL },
            { GTP_EXT_PROTO_CONF,   GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_QOS_UMTS,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ADDR,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{     /* checked, SGSN -> GGSN */
      GTP_MSG_UPDATE_PDP_REQ, {
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_TEID,         GTP_MANDATORY },
            { GTP_EXT_TEID_CP,      GTP_CONDITIONAL },
            { GTP_EXT_NSAPI,  GTP_MANDATORY },
            { GTP_EXT_TRACE_REF,    GTP_OPTIONAL },
            { GTP_EXT_TRACE_TYPE,   GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_QOS_UMTS,     GTP_MANDATORY },
            { GTP_EXT_TFT,          GTP_OPTIONAL },
            { GTP_EXT_TRIGGER_ID,   GTP_OPTIONAL },
            { GTP_EXT_OMC_ID, GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{     /* checked, GGSN -> SGSN */
      GTP_MSG_UPDATE_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_RECOVER,      GTP_OPTIONAL },
            { GTP_EXT_TEID,         GTP_CONDITIONAL },
            { GTP_EXT_TEID_CP,      GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ID,      GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_QOS_UMTS,     GTP_CONDITIONAL },
            { GTP_EXT_CHRG_ADDR,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DELETE_PDP_REQ, {
            { GTP_EXT_TEAR_IND,     GTP_CONDITIONAL },
            { GTP_EXT_NSAPI,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_DELETE_PDP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_ERR_IND, {
            { GTP_EXT_TEID,         GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_TEID_CP,      GTP_MANDATORY },
            { GTP_EXT_USER_ADDR,    GTP_MANDATORY },
            { GTP_EXT_APN,          GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_REJ_REQ, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_TEID_CP,      GTP_MANDATORY },
            { GTP_EXT_USER_ADDR,    GTP_MANDATORY },
            { GTP_EXT_APN,          GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_PDU_NOTIFY_REJ_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SUPP_EXT_HDR, {
            { GTP_EXT_HDR_LIST,     GTP_MANDATORY },
            { 0,              0 }
      }
},
{
      GTP_MSG_SEND_ROUT_INFO_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SEND_ROUT_INFO_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_MAP_CAUSE,    GTP_OPTIONAL },
            { GTPv1_EXT_MS_REASON,  GTP_OPTIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FAIL_REP_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FAIL_REP_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_MAP_CAUSE,    GTP_OPTIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_MS_PRESENT_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_MS_PRESENT_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_IDENT_REQ, {
            { GTP_EXT_RAI,          GTP_MANDATORY },
            { GTP_EXT_PTMSI,  GTP_MANDATORY },
            { GTP_EXT_PTMSI_SIG,    GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_IDENT_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_AUTH_TRI,     GTP_CONDITIONAL },
            { GTP_EXT_AUTH_QUI,     GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SGSN_CNTXT_REQ, {
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_RAI,          GTP_MANDATORY },
            { GTP_EXT_TLLI,         GTP_CONDITIONAL },
            { GTP_EXT_PTMSI,  GTP_CONDITIONAL },
            { GTP_EXT_PTMSI_SIG,    GTP_CONDITIONAL },
            { GTP_EXT_MS_VALID,     GTP_OPTIONAL },
            { GTP_EXT_TEID_CP,      GTP_MANDATORY },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SGSN_CNTXT_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_IMSI,         GTP_CONDITIONAL },
            { GTP_EXT_TEID_CP,      GTP_CONDITIONAL },
            { GTP_EXT_RP_SMS, GTP_OPTIONAL },
            { GTP_EXT_RP,           GTP_OPTIONAL },
            { GTP_EXT_PKT_FLOW_ID,  GTP_OPTIONAL },
            { GTP_EXT_MM_CNTXT,     GTP_CONDITIONAL },
            { GTP_EXT_PDP_CNTXT,    GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_SGSN_CNTXT_ACK, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_TEID_II,      GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FORW_RELOC_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_TEID_CP,      GTP_MANDATORY },
            { GTP_EXT_RANAP_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_MM_CNTXT,     GTP_MANDATORY },
            { GTP_EXT_PDP_CNTXT,    GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_MANDATORY },
            { GTP_EXT_TARGET_ID,    GTP_MANDATORY },
            { GTP_EXT_UTRAN_CONT,   GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FORW_RELOC_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_TEID_CP,      GTP_CONDITIONAL },
            { GTP_EXT_RANAP_CAUSE,  GTP_CONDITIONAL },
            { GTP_EXT_GSN_ADDR,     GTP_CONDITIONAL },
            { GTP_EXT_UTRAN_CONT,   GTP_OPTIONAL },
            { GTP_EXT_RAB_SETUP,    GTP_CONDITIONAL },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FORW_RELOC_COMP, {
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_RELOC_CANCEL_REQ, {
            { GTP_EXT_IMSI,         GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_RELOC_CANCEL_RESP, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FORW_RELOC_ACK, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FORW_SRNS_CNTXT, {
            { GTP_EXT_RAB_CNTXT,    GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      GTP_MSG_FORW_SRNS_CNTXT_ACK, {
            { GTP_EXT_CAUSE,  GTP_MANDATORY },
            { GTP_EXT_PRIV_EXT,     GTP_OPTIONAL },
            { 0,              0 }
      }
},
{
      0, {
            { 0,              0 }
      }
}
};

static int
check_field_presence(guint8 message, guint8 field, int *position) {

      guint             i = 0;
      _gtp_mess_items         *mess_items;

      switch(gtp_version) {
            case 0:
                  mess_items = gprs_mess_items;
                  break;
            case 1:
                  mess_items = umts_mess_items;
                  break;
            default:
                  return -2;
      }

      while (mess_items[i].code) {
            if (mess_items[i].code == message) {

                  while (mess_items[i].fields[*position].code) {
                        if (mess_items[i].fields[*position].code == field) {
                              (*position)++;
                              return 0;
                        } else {
                        if (mess_items[i].fields[*position].presence == GTP_MANDATORY) {
                              return mess_items[i].fields[(*position)++].code;
                        } else {
                              (*position)++;
                        }}
                  }
                  return -1;
            }
            i++;
      }

      return -2;
}

/* Decoders of fields in extension headers, each function returns no of bytes from field */

/* GPRS:    9.60 v7.6.0, chapter
 * UMTS:    29.060 v4.0, chapter
 */
static int
decode_gtp_cause(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      cause;

      cause = tvb_get_guint8(tvb, offset+1);

      proto_tree_add_uint(tree, hf_gtp_cause, tvb, offset, 2, cause);

      return 2;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.2
 * UMTS:    29.060 v4.0, chapter 7.7.2
 */
static int
decode_gtp_imsi(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      imsi_val[8];
      gchar *imsi_str;

      tvb_memcpy(tvb, imsi_val, offset+1, 8);
      imsi_str = imsi_to_str (imsi_val);

      proto_tree_add_string (tree, hf_gtp_imsi, tvb, offset, 9, imsi_str);

      return 9;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.3
 * UMTS:    29.060 v4.0, chapter 7.7.3
 */
static int
decode_gtp_rai(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      proto_tree  *ext_tree_rai;
      proto_item  *te;
      guint8            byte[3];
      guint16           mnc, mcc;

      te = proto_tree_add_text(tree, tvb, offset, 1, val_to_str(GTP_EXT_RAI, gtp_val, "Unknown message"));
      ext_tree_rai = proto_item_add_subtree(te, ett_gtp_rai);

      byte[0] = tvb_get_guint8 (tvb, offset + 1);
      byte[1] = tvb_get_guint8 (tvb, offset + 2);
      byte[2] = tvb_get_guint8 (tvb, offset + 3);
      mcc = (byte[0] & 0x0F) * 100 + ((byte[0] & 0xF0) >> 4) * 10  + (byte[1] & 0x0F );
      if ((byte[1] & 0xF0) == 0xF0)
            mnc = (byte[2] & 0x0F) * 10  + ((byte[2] & 0xF0) >> 4);
      else
            mnc = (byte[2] & 0x0F) * 100 + ((byte[2] & 0xF0) >> 4 ) * 10  + ((byte[1] & 0xF0) >> 4);

      proto_tree_add_uint(ext_tree_rai, hf_gtp_rai_mcc, tvb, offset+1, 2, mcc);
      proto_tree_add_uint(ext_tree_rai, hf_gtp_rai_mnc, tvb, offset+2, 2, mnc);
      proto_tree_add_uint(ext_tree_rai, hf_gtp_rai_lac, tvb, offset+4, 2, tvb_get_ntohs (tvb, offset+4));
      proto_tree_add_uint(ext_tree_rai, hf_gtp_rai_rac, tvb, offset+6, 1, tvb_get_guint8 (tvb, offset+6));

      return 7;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.4, page 39
 * UMTS:    29.060 v4.0, chapter 7.7.4, page 47
 */
static int
decode_gtp_tlli(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint32     tlli;

      tlli = tvb_get_ntohl(tvb, offset+1);
      proto_tree_add_uint(tree, hf_gtp_tlli, tvb, offset, 5, tlli);

      return 5;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.5, page 39
 * UMTS:    29.060 v4.0, chapter 7.7.5, page 47
 */
static int
decode_gtp_ptmsi(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint32     ptmsi;

      ptmsi = tvb_get_ntohl (tvb, offset+1);
      proto_tree_add_uint (tree, hf_gtp_ptmsi, tvb, offset, 5, ptmsi);

      return 5;
}

/* adjust - how many bytes before offset should be highlighted
 */
static int
decode_qos_gprs(tvbuff_t *tvb, int offset, proto_tree *tree, gchar* qos_str, guint8 adjust) {

      guint8            spare1, delay, reliability, peak, spare2,  precedence, spare3, mean;
      proto_tree  *ext_tree_qos;
      proto_item  *te;

      spare1 = tvb_get_guint8(tvb, offset) & 0xC0;
      delay = tvb_get_guint8(tvb, offset) & 0x38;
      reliability = tvb_get_guint8(tvb, offset) & 0x07;
      peak = tvb_get_guint8(tvb, offset+1) & 0xF0;
      spare2 = tvb_get_guint8(tvb, offset+1) & 0x08;
      precedence = tvb_get_guint8(tvb, offset+1) & 0x07;
      spare3 = tvb_get_guint8(tvb, offset+2) & 0xE0;
      mean = tvb_get_guint8(tvb, offset+2) & 0x1F;

      te = proto_tree_add_text(tree, tvb, offset-adjust, 3+adjust, "%s: delay: %u, reliability: %u, peak: %u, precedence: %u, mean: %u",
                                                                qos_str, (delay >> 3) & 0x07, reliability, (peak >> 4) & 0x0F, precedence, mean);
      ext_tree_qos = proto_item_add_subtree(te, ett_gtp_qos);

      if (adjust != 0) {
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_spare1, tvb, offset, 1, spare1);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_delay, tvb, offset, 1, delay);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_reliability, tvb, offset, 1, reliability);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_peak, tvb, offset+1, 1, peak);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_spare2, tvb, offset+1, 1, spare2);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_precedence, tvb, offset+1, 1, precedence);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_spare3, tvb, offset+2, 1, spare3);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_mean, tvb, offset+2, 1, mean);
      }

      return 3;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.6, page 39
 *          4.08
 *          3.60
 * UMTS:    not present
 * TODO:    check if length is included: ETSI 4.08 vs 9.60
 */
static int
decode_gtp_qos_gprs(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      return (1+decode_qos_gprs(tvb, offset+1, tree, "Quality of Service", 1));

}

/* GPRS:    9.60 v7.6.0, chapter 7.9.7, page 39
 * UMTS:    29.060 v4.0, chapter 7.7.6, page 47
 */
static int
decode_gtp_reorder(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      reorder;

      reorder = tvb_get_guint8(tvb, offset+1) & 0x01;
      proto_tree_add_boolean(tree, hf_gtp_reorder, tvb, offset, 2, reorder);

      return 2;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.8, page 40
 *          4.08 v7.1.2, chapter 10.5.3.1+
 * UMTS:    29.060 v4.0, chapter 7.7.7
 * TODO: Add blurb support by registering items in the protocol registration
 */
static int
decode_gtp_auth_tri(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      proto_tree  *ext_tree_auth_tri;
      proto_item  *te;

      te = proto_tree_add_text(tree, tvb, offset, 29, val_to_str(GTP_EXT_AUTH_TRI, gtp_val, "Unknown message"));
      ext_tree_auth_tri = proto_item_add_subtree(tree, ett_gtp_auth_tri);

      proto_tree_add_text(ext_tree_auth_tri, tvb, offset+1, 16, "RAND: %s", tvb_bytes_to_str(tvb, offset+1, 16));
      proto_tree_add_text(ext_tree_auth_tri, tvb, offset+17, 4, "SRES: %s", tvb_bytes_to_str(tvb, offset+17, 4));
      proto_tree_add_text(ext_tree_auth_tri, tvb, offset+21, 8, "Kc: %s", tvb_bytes_to_str(tvb, offset+21, 8));

      return 1+16+4+8;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.9, page 40
 *          9.02 v7.7.0, page 1090
 * UMTS:    29.060 v4.0, chapter 7.7.8, page 48
 *          29.002 v4.2.1, chapter 17.5, page 268
 */
static int
decode_gtp_map_cause(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      map_cause;

      map_cause = tvb_get_guint8(tvb, offset+1);
      proto_tree_add_uint (tree, hf_gtp_map_cause, tvb, offset, 2, map_cause);

      return 2;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.10, page 41
 * UMTS:    29.060 v4.0, chapter 7.7.9, page 48
 */
static int
decode_gtp_ptmsi_sig(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint32     ptmsi_sig;

      ptmsi_sig = tvb_get_ntoh24(tvb, offset+1);
      proto_tree_add_uint(tree, hf_gtp_ptmsi_sig, tvb, offset, 4, ptmsi_sig);

      return 4;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.11, page 41
 * UMTS:    29.060 v4.0, chapter 7.7.10, page 49
 */
static int
decode_gtp_ms_valid(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      ms_valid;

      ms_valid = tvb_get_guint8(tvb, offset+1) & 0x01;
      proto_tree_add_boolean (tree, hf_gtp_ms_valid, tvb, offset, 2, ms_valid);

      return 2;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.12, page 41
 * UMTS:    29.060 v4.0, chapter 7.7.11, page 49
 */
static int
decode_gtp_recovery(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      recovery;

      recovery = tvb_get_guint8(tvb, offset+1);
      proto_tree_add_uint (tree, hf_gtp_recovery, tvb, offset, 2, recovery);

      return 2;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.13, page 42
 * UMTS:    29.060 v4.0, chapter 7.7.12, page 49
 */
static int
decode_gtp_sel_mode(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      sel_mode;

      sel_mode = tvb_get_guint8(tvb, offset+1) & 0x03;
      proto_tree_add_uint(tree, hf_gtp_sel_mode, tvb, offset, 2, sel_mode);

      return 2;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.14, page 42
 * UMTS:    29.060 v4.0, chapter 7.7.13, page 50
 */
static int
decode_gtp_16(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16     ext_flow_label;
      guint32     teid_data;

      switch (gtp_version) {
            case 0:
                  ext_flow_label = tvb_get_ntohs(tvb, offset+1);
                  proto_tree_add_uint(tree, hf_gtp_ext_flow_label, tvb, offset, 3, ext_flow_label);

                  return 3;
            case 1:
                  teid_data = tvb_get_ntohl(tvb, offset+1);
                  proto_tree_add_uint(tree, hf_gtp_teid_data, tvb, offset, 5, teid_data);

                  return 5;
            default:
                  proto_tree_add_text(tree, tvb, offset, 1, "Flow label/TEID Data I : GTP version not supported");

                  return 3;
      }
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.15, page 42
 * UMTS:    29.060 v4.0, chapter 7.7.14, page 42
 */
static int
decode_gtp_17(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           flow_sig;
      guint32           teid_cp;

      switch (gtp_version) {
            case 0:
                  flow_sig = tvb_get_ntohs(tvb, offset+1);
                  proto_tree_add_uint (tree, hf_gtp_flow_sig, tvb, offset, 3, flow_sig);
                  return 3;
            case 1:
                  teid_cp = tvb_get_ntohl(tvb, offset+1);
                  proto_tree_add_uint (tree, hf_gtp_teid_cp, tvb, offset, 5, teid_cp);
                  return 5;
            default:
                  proto_tree_add_text(tree, tvb, offset, 1, "Flow label signalling/TEID control plane : GTP version not supported");
                  return 3;
      }
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.16, page 42
 * UMTS:    29.060 v4.0, chapter 7.7.15, page 51
 */
static int
decode_gtp_18(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           flow_ii;
      guint32           teid_ii;
      proto_tree  *ext_tree_flow_ii;
      proto_item  *te;

      switch (gtp_version) {
            case 0:
                  te = proto_tree_add_text(tree, tvb, offset, 4, val_to_str(GTP_EXT_FLOW_II, gtp_val, "Unknown message"));
                  ext_tree_flow_ii = proto_item_add_subtree (te, ett_gtp_flow_ii);

                  proto_tree_add_uint(ext_tree_flow_ii, hf_gtp_nsapi, tvb, offset+1, 1, tvb_get_guint8(tvb, offset+1) & 0x0F);

                  flow_ii = tvb_get_ntohs(tvb, offset+2);
                  proto_tree_add_uint(ext_tree_flow_ii, hf_gtp_flow_ii, tvb, offset+2, 2, flow_ii);

                  return 4;
            case 1:
                  te = proto_tree_add_text (tree, tvb, offset, 6, val_to_str(GTP_EXT_TEID_II, gtp_val, "Unknown message"));
                  ext_tree_flow_ii = proto_item_add_subtree(te, ett_gtp_flow_ii);

                  proto_tree_add_uint(ext_tree_flow_ii, hf_gtp_nsapi, tvb, offset+1, 1, tvb_get_guint8(tvb, offset+1) & 0x0F);


                  teid_ii = tvb_get_ntohl(tvb, offset+2);
                  proto_tree_add_uint(ext_tree_flow_ii, hf_gtp_teid_ii, tvb, offset+2, 4, teid_ii);

                  return 6;
            default:
                  proto_tree_add_text(tree, tvb, offset, 1, "Flow data II/TEID Data II : GTP Version not supported");

                  return 4;
      }
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.16A, page 43
 * UMTS:    29.060 v4.0, chapter 7.7.16, page 51
 * Check if all ms_reason types are included
 */
static int
decode_gtp_19(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            field19;

      field19 = tvb_get_guint8(tvb, offset+1);

      switch (gtp_version) {
            case 0:
                  proto_tree_add_uint(tree, hf_gtp_ms_reason, tvb, offset, 2, field19);
                  break;
            case 1:
                  proto_tree_add_boolean(tree, hf_gtp_tear_ind, tvb, offset, 2, field19 & 0x01);
                  break;
            default:
                  proto_tree_add_text(tree, tvb, offset, 1, "Information Element Type = 19 : GTP Version not supported");
                  break;
      }

      return 2;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.17, page 51
 */
static int
decode_gtp_nsapi(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            nsapi;

      nsapi = tvb_get_guint8(tvb, offset+1) & 0x0F;
      proto_tree_add_uint(tree, hf_gtp_nsapi, tvb, offset, 2, nsapi);

      return 2;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.18, page 52
 */
static int
decode_gtp_ranap_cause(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            ranap;

      ranap = tvb_get_guint8(tvb, offset+1);

      if(ranap > 0 && ranap <=64)
            proto_tree_add_uint_format(tree, hf_gtp_ranap_cause, tvb, offset, 2, 
                  ranap, "%s (Radio Network Layer Cause) : %s (%u)", 
                  val_to_str(GTP_EXT_RANAP_CAUSE, gtp_val, "Unknown"), 
                  val_to_str(ranap, ranap_cause_type, "Unknown RANAP Cause"), ranap);

      if(ranap > 64 && ranap <=80)
            proto_tree_add_uint_format(tree, hf_gtp_ranap_cause, tvb, offset, 2, 
                  ranap, "%s (Transport Layer Cause) : %s (%u)", 
                  val_to_str(GTP_EXT_RANAP_CAUSE, gtp_val, "Unknown"), 
                  val_to_str(ranap, ranap_cause_type, "Unknown RANAP Cause"), ranap);

      if(ranap > 80 && ranap <=96)
            proto_tree_add_uint_format(tree, hf_gtp_ranap_cause, tvb, offset, 2, 
                  ranap, "%s (NAS Cause) : %s (%u)", 
                  val_to_str(GTP_EXT_RANAP_CAUSE, gtp_val, "Unknown"), 
                  val_to_str(ranap, ranap_cause_type, "Unknown RANAP Cause"), ranap);

      if(ranap > 96 && ranap <=112)
            proto_tree_add_uint_format(tree, hf_gtp_ranap_cause, tvb, offset, 2, ranap, 
                  "%s (Protocol Cause) : %s (%u)", 
                  val_to_str(GTP_EXT_RANAP_CAUSE, gtp_val, "Unknown"), 
                  val_to_str(ranap, ranap_cause_type, "Unknown RANAP Cause"), ranap);

      if(ranap > 112 && ranap <=128)
            proto_tree_add_uint_format(tree, hf_gtp_ranap_cause, tvb, offset, 2, ranap, 
                  "%s (Miscellaneous Cause) : %s (%u)", 
                  val_to_str(GTP_EXT_RANAP_CAUSE, gtp_val, "Unknown"), 
                  val_to_str(ranap, ranap_cause_type, "Unknown RANAP Cause"), ranap);

      if(ranap > 128 /* && ranap <=255 */)
            proto_tree_add_uint_format(tree, hf_gtp_ranap_cause, tvb, offset, 2, ranap, 
                  "%s (Non-standard Cause) : %s (%u)", 
                  val_to_str(GTP_EXT_RANAP_CAUSE, gtp_val, "Unknown"), 
                  val_to_str(ranap, ranap_cause_type, "Unknown RANAP Cause"), ranap);

      return 2;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.19, page 52
 */
static int
decode_gtp_rab_cntxt(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            nsapi, dl_pdcp_seq, ul_pdcp_seq;
      guint16           dl_gtpu_seq, ul_gtpu_seq;
      proto_tree  *ext_tree_rab_cntxt;
      proto_item  *te;

      te = proto_tree_add_text(tree, tvb, offset, 8, val_to_str(GTP_EXT_RAB_CNTXT, gtp_val, "Unknown message"));
      ext_tree_rab_cntxt = proto_item_add_subtree(te, ett_gtp_rab_cntxt);

      nsapi = tvb_get_guint8(tvb, offset+1) & 0x0F;
      dl_gtpu_seq = tvb_get_ntohs(tvb, offset+2);
      ul_gtpu_seq = tvb_get_ntohs(tvb, offset+4);
      dl_pdcp_seq = tvb_get_guint8(tvb, offset+6);
      ul_pdcp_seq = tvb_get_guint8(tvb, offset+7);

      proto_tree_add_uint (ext_tree_rab_cntxt, hf_gtp_nsapi, tvb, offset+1, 1, nsapi);
      proto_tree_add_uint(ext_tree_rab_cntxt, hf_gtp_rab_gtpu_dn, tvb, offset+2, 2, dl_gtpu_seq);
      proto_tree_add_uint(ext_tree_rab_cntxt, hf_gtp_rab_gtpu_up, tvb, offset+4, 2, ul_gtpu_seq);
      proto_tree_add_uint(ext_tree_rab_cntxt, hf_gtp_rab_pdu_dn, tvb, offset+6, 1, dl_pdcp_seq);
      proto_tree_add_uint(ext_tree_rab_cntxt, hf_gtp_rab_pdu_up, tvb, offset+7, 1, ul_pdcp_seq);

      return 8;
}


/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.20, page 53
 */
static int
decode_gtp_rp_sms(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            rp_sms;

      rp_sms = tvb_get_guint8(tvb, offset+1) & 0x07;
      proto_tree_add_uint(tree, hf_gtp_rp_sms, tvb, offset, 2, rp_sms);

      return 2;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.21, page 53
 */
static int
decode_gtp_rp(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      proto_tree  *ext_tree_rp;
      proto_item  *te;
      guint8            nsapi, rp, spare;

      nsapi = tvb_get_guint8(tvb, offset+1) & 0xF0;
      spare = tvb_get_guint8(tvb, offset+1) & 0x08;
      rp = tvb_get_guint8(tvb, offset+1) & 0x07;

      te = proto_tree_add_uint_format(tree, hf_gtp_rp, tvb, offset, 2, rp, "Radio Priority for NSAPI(%u) : %u", nsapi, rp);
      ext_tree_rp = proto_item_add_subtree(tree, ett_gtp_rp);

      proto_tree_add_uint(ext_tree_rp, hf_gtp_rp_nsapi, tvb, offset+1, 1, nsapi);
      proto_tree_add_uint(ext_tree_rp, hf_gtp_rp_spare, tvb, offset+1, 1, spare);
      proto_tree_add_uint(ext_tree_rp, hf_gtp_rp, tvb, offset+1, 1, rp);

      return 2;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.22, page 53
 */
static int
decode_gtp_pkt_flow_id(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      proto_tree  *ext_tree_pkt_flow_id;
      proto_item  *te;
      guint8            nsapi, pkt_flow_id;

      nsapi = tvb_get_guint8(tvb, offset+1) & 0x0F;
      pkt_flow_id = tvb_get_guint8(tvb, offset+2);

      te = proto_tree_add_uint_format (tree, hf_gtp_pkt_flow_id, tvb, offset, 
            3, pkt_flow_id, "Packet Flow ID for NSAPI(%u) : %u", nsapi, 
            pkt_flow_id);
      ext_tree_pkt_flow_id = proto_item_add_subtree(tree, ett_gtp_pkt_flow_id);

      proto_tree_add_uint(ext_tree_pkt_flow_id, hf_gtp_nsapi, tvb, offset+1, 1, nsapi);
      proto_tree_add_uint_format(ext_tree_pkt_flow_id, hf_gtp_pkt_flow_id, tvb, 
            offset+2, 1, pkt_flow_id, "%s : %u", 
            val_to_str(GTP_EXT_PKT_FLOW_ID, gtp_val, "Unknown message"), 
            pkt_flow_id);

      return 3;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.23, page 53
 * TODO: Differenciate these uints?
 */
static int
decode_gtp_chrg_char(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           chrg_char;
      proto_item  *te;
      proto_tree  *ext_tree_chrg_char;

      chrg_char = tvb_get_ntohs(tvb, offset+1);

      te = proto_tree_add_uint (tree, hf_gtp_chrg_char, tvb, offset, 3, chrg_char);
      /*"%s: %x", val_to_str (GTP_EXT_CHRG_CHAR, gtp_val, "Unknown message"), chrg_char);*/
      ext_tree_chrg_char = proto_item_add_subtree(te, ett_gtp_chrg_char);

      proto_tree_add_uint (ext_tree_chrg_char, hf_gtp_chrg_char_s, tvb, offset+1, 2, chrg_char);
      proto_tree_add_uint (ext_tree_chrg_char, hf_gtp_chrg_char_n, tvb, offset+1, 2, chrg_char);
      proto_tree_add_uint (ext_tree_chrg_char, hf_gtp_chrg_char_p, tvb, offset+1, 2, chrg_char);
      proto_tree_add_uint (ext_tree_chrg_char, hf_gtp_chrg_char_f, tvb, offset+1, 2, chrg_char);
      proto_tree_add_uint (ext_tree_chrg_char, hf_gtp_chrg_char_h, tvb, offset+1, 2, chrg_char);
      proto_tree_add_uint (ext_tree_chrg_char, hf_gtp_chrg_char_r, tvb, offset+1, 2, chrg_char);

      return 3;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.24, page
 */
static int
decode_gtp_trace_ref(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           trace_ref;

      trace_ref = tvb_get_ntohs(tvb, offset+1);

      proto_tree_add_uint (tree, hf_gtp_trace_ref, tvb, offset, 3, trace_ref);

      return 3;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.25, page
 */
static int
decode_gtp_trace_type(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           trace_type;

      trace_type = tvb_get_ntohs(tvb, offset+1);

      proto_tree_add_uint (tree, hf_gtp_trace_type, tvb, offset, 3, trace_type);

      return 3;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.16A
 * UMTS:    29.060 v4.0, chapter 7.7.25A, page
 */
static int
decode_gtp_ms_reason(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            reason;

      reason = tvb_get_guint8(tvb, offset+1);

      proto_tree_add_uint (tree, hf_gtp_ms_reason, tvb, offset, 2, reason);

      return 2;
}


/* GPRS:    12.15 v7.6.0, chapter 7.3.3, page 45
 * UMTS:    33.015
 */
static int
decode_gtp_tr_comm(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8      tr_command;

      tr_command = tvb_get_guint8(tvb, offset+1);

      proto_tree_add_uint (tree, hf_gtp_tr_comm, tvb, offset, 2, tr_command);

      return 2;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.17, page 43
 * UMTS:    29.060 v4.0, chapter 7.7.26, page 55
 */
static int
decode_gtp_chrg_id(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint32     chrg_id;

      chrg_id = tvb_get_ntohl(tvb, offset+1);
      proto_tree_add_uint (tree, hf_gtp_chrg_id, tvb, offset, 5, chrg_id);

      return 5;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.18, page 43
 * UMTS:    29.060 v4.0, chapter 7.7.27, page 55
 */
static int
decode_gtp_user_addr(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;
      guint8            pdp_typ, pdp_org;
      guint32           addr_ipv4;
      struct            e_in6_addr addr_ipv6;
      proto_tree  *ext_tree_user;
      proto_item  *te;


      length = tvb_get_ntohs(tvb, offset+1);
      pdp_org = tvb_get_guint8(tvb, offset+3) & 0x0F;
      pdp_typ = tvb_get_guint8(tvb, offset+4);

      te = proto_tree_add_text(tree, tvb, offset, 3+length, "%s (%s/%s)",
          val_to_str(GTP_EXT_USER_ADDR, gtp_val, "Unknown message"),
          val_to_str(pdp_org, pdp_org_type, "Unknown PDP Organization"),
          val_to_str(pdp_typ, pdp_type, "Unknown PDP Type"));
      ext_tree_user = proto_item_add_subtree(te, ett_gtp_user);

      proto_tree_add_text(ext_tree_user, tvb, offset+1, 2, "Length : %u", length);
      proto_tree_add_uint(ext_tree_user, hf_gtp_user_addr_pdp_org, tvb, offset+3, 1, pdp_org);
      proto_tree_add_uint(ext_tree_user, hf_gtp_user_addr_pdp_type, tvb, offset+4, 1, pdp_typ);

      if (length == 2) {
            if (pdp_org == 0 && pdp_typ == 1)
                  proto_item_append_text(te, " (Point to Point Protocol)");
            else if (pdp_typ == 2)
                  proto_item_append_text(te, " (Octet Stream Protocol)");
      } else if (length > 2) {
            switch (pdp_typ) {
                  case 0x21:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+5, sizeof addr_ipv4);
                        proto_tree_add_ipv4(ext_tree_user, hf_gtp_user_ipv4, tvb, offset+5, 4, addr_ipv4);
                        proto_item_append_text(te, " : %s", ip_to_str((guint8 *)&addr_ipv4));
                        break;
                  case 0x57:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+5, sizeof addr_ipv6);
                        proto_tree_add_ipv6 (ext_tree_user, hf_gtp_user_ipv6, tvb, offset+5, 16, (guint8 *)&addr_ipv6);
                        proto_item_append_text(te, " : %s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                        break;
            }
      } else
            proto_item_append_text(te, " : empty PDP Address");

      return 3+length;
}

static int
decode_triplet(tvbuff_t *tvb, int offset, proto_tree *tree, guint16 count) {

      proto_tree  *ext_tree_trip;
      proto_item  *te_trip;
      guint16           i;

      for (i=0;i<count;i++) {
            te_trip = proto_tree_add_text(tree, tvb, offset+i*28, 28, "Triplet no%x", i);
            ext_tree_trip = proto_item_add_subtree(te_trip, ett_gtp_trip);

            proto_tree_add_text(ext_tree_trip, tvb, offset+i*28, 16, "RAND: %s", tvb_bytes_to_str(tvb, offset+i*28, 16));
            proto_tree_add_text(ext_tree_trip, tvb, offset+i*28+16, 4, "SRES: %s", tvb_bytes_to_str(tvb, offset+i*28+16, 4));
            proto_tree_add_text(ext_tree_trip, tvb, offset+i*28+20, 8, "Kc: %s", tvb_bytes_to_str(tvb, offset+i*28+20, 8));
      }

      return count*28;
}

/* adjust - how many bytes before quintuplet should be highlighted
 */
static int
decode_quintuplet(tvbuff_t *tvb, int offset, proto_tree *tree, guint16 count, guint8 adjust) {

      proto_tree  *ext_tree_quint;
      proto_item  *te_quint;
      guint16           q_len, xres_len, auth_len, q_offset, i;

      q_offset = 0;

      for (i=0;i<count;i++) {

            offset = offset + q_offset;

            q_len = tvb_get_ntohs(tvb, offset);

            te_quint = proto_tree_add_text(tree, tvb, offset-adjust, q_len+adjust, "Quintuplet #%x", i);
            ext_tree_quint = proto_item_add_subtree(te_quint, ett_gtp_quint);

            proto_tree_add_text(ext_tree_quint, tvb, offset, 2, "Length: %x", q_len);
            proto_tree_add_text(ext_tree_quint, tvb, offset+2, 16, "RAND: %s", tvb_bytes_to_str(tvb, offset+2, 16));
            xres_len = tvb_get_ntohs(tvb, offset+18);
            proto_tree_add_text(ext_tree_quint, tvb, offset+18, 2, "XRES length: %u", xres_len);
            proto_tree_add_text(ext_tree_quint, tvb, offset+20, xres_len, "XRES: %s", tvb_bytes_to_str(tvb, offset+20, xres_len));
            proto_tree_add_text(ext_tree_quint, tvb, offset+20+xres_len, 16, "Quintuplet ciphering key: %s", tvb_bytes_to_str(tvb, offset+20+xres_len, 16));
            proto_tree_add_text(ext_tree_quint, tvb, offset+36+xres_len, 16, "Quintuplet integrity key: %s", tvb_bytes_to_str(tvb, offset+36+xres_len, 16));
            auth_len = tvb_get_ntohs(tvb, offset+52+xres_len);
            proto_tree_add_text(ext_tree_quint, tvb, offset+52+xres_len, 2, "Authentication length: %u", auth_len);
            proto_tree_add_text(ext_tree_quint, tvb, offset+54+xres_len, auth_len, "AUTH: %s", tvb_bytes_to_str(tvb, offset+54+xres_len, auth_len));

            q_offset = q_offset + q_len + 2;
      }

      return q_offset;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.19 page
 * UMTS:    29.060 v4.0, chapter 7.7.28 page 57
 * TODO:    - check if for quintuplets first 2 bytes are length, according to AuthQuint
 *          - finish displaying last 3 parameters
 */
static int
decode_gtp_mm_cntxt(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length, quint_len, net_cap, con_len;
      guint8            cksn, count, sec_mode, cipher, trans_id, proto_disc, message, drx_split, drx_len, drx_ccch, non_drx_timer;
      proto_tree  *ext_tree_mm;
      proto_item  *te;

      te = proto_tree_add_text(tree, tvb, offset, 1, val_to_str(GTP_EXT_MM_CNTXT, gtp_val, "Unknown message"));
      ext_tree_mm = proto_item_add_subtree(te, ett_gtp_mm);

      length = tvb_get_ntohs(tvb, offset+1);
      if (length < 1) return 3;

      cksn = tvb_get_guint8(tvb, offset+3) & 0x07;
      sec_mode = (tvb_get_guint8(tvb, offset+4) >> 6) & 0x03;
      count = (tvb_get_guint8(tvb, offset+4) >> 3) & 0x07;
      cipher = tvb_get_guint8(tvb, offset+4) & 0x07;

      proto_tree_add_text(ext_tree_mm, tvb, offset+1, 2, "Length: %x", length);
      proto_tree_add_text(ext_tree_mm, tvb, offset+3, 1, "Ciphering Key Sequence Number: %u", cksn);
      if (gtp_version != 0) {
            proto_tree_add_text(ext_tree_mm, tvb, offset+3, 1, "Security type: %u (%s)", sec_mode,
                                val_to_str(sec_mode, mm_sec_modep, "Unknown"));
      } else {
            sec_mode = 1;
      }

      proto_tree_add_text(ext_tree_mm, tvb, offset+4, 1, "No of triplets: %u", count);

      switch (sec_mode) {
            case 0:
                  if (cipher == 0) {
                        proto_tree_add_text(ext_tree_mm, tvb, offset+4, 1, "Ciphering: no ciphering");
                  } else {
                        proto_tree_add_text(ext_tree_mm, tvb, offset+4, 1, "Ciphering: GEA/%u", cipher);
                  }
                  proto_tree_add_text(ext_tree_mm, tvb, offset+5, 16, "Ciphering key CK: %s", tvb_bytes_to_str(tvb, offset+5, 16));
                  proto_tree_add_text(ext_tree_mm, tvb, offset+21, 16, "Integrity key CK: %s", tvb_bytes_to_str(tvb, offset+21, 16));
                  quint_len = tvb_get_ntohs(tvb, offset+37);
                  proto_tree_add_text(ext_tree_mm, tvb, offset+37, 2, "Quintuplets length: %x", quint_len);

                  offset = offset + decode_quintuplet(tvb, offset+39, ext_tree_mm, count, 0) + 39;


                  break;
            case 1:
                  if (cipher == 0) {
                        proto_tree_add_text(ext_tree_mm, tvb, offset+4, 1, "Ciphering: no ciphering");
                  } else {
                        proto_tree_add_text(ext_tree_mm, tvb, offset+4, 1, "Ciphering: GEA/%u", cipher);
                  }
                  proto_tree_add_text(ext_tree_mm, tvb, offset+5, 8, "Ciphering key Kc: %s", tvb_bytes_to_str(tvb, offset+5, 8));

                  offset = offset + decode_triplet(tvb, offset+13, ext_tree_mm, count) + 13;

                  break;
            case 2:
                  proto_tree_add_text(ext_tree_mm, tvb, offset+5, 16, "Ciphering key CK: %s", tvb_bytes_to_str(tvb, offset+5, 16));
                  proto_tree_add_text(ext_tree_mm, tvb, offset+21, 16, "Integrity key CK: %s", tvb_bytes_to_str(tvb, offset+21, 16));
                  quint_len = tvb_get_ntohs(tvb, offset+37);
                  proto_tree_add_text(ext_tree_mm, tvb, offset+37, 2, "Quintuplets length: %x", quint_len);

                  offset = offset + decode_quintuplet(tvb, offset+39, ext_tree_mm, count, 0) + 39;

                  break;
            case 3:
                  if (cipher == 0) {
                        proto_tree_add_text(ext_tree_mm, tvb, offset+4, 1, "Ciphering: no ciphering");
                  } else {
                        proto_tree_add_text(ext_tree_mm, tvb, offset+4, 1, "Ciphering: GEA/%u", cipher);
                  }
                  proto_tree_add_text(ext_tree_mm, tvb, offset+5, 8, "Ciphering key Kc: %s", tvb_bytes_to_str(tvb, offset+5, 8));
                  quint_len = tvb_get_ntohs(tvb, offset+13);
                  proto_tree_add_text(ext_tree_mm, tvb, offset+13, 2, "Quintuplets length: %x", quint_len);

                  offset = offset + decode_quintuplet(tvb, offset+15, ext_tree_mm, count, 0) + 15;

                  break;
            default:
                  break;
      }


      drx_split = tvb_get_guint8(tvb, offset);
      drx_len = (tvb_get_guint8(tvb, offset+1) >> 4) & 0x0F;
      drx_ccch = (tvb_get_guint8(tvb, offset+1) >> 3) & 0x01;
      non_drx_timer = tvb_get_guint8(tvb, offset+1) & 0x07;

      net_cap     = tvb_get_ntohs(tvb, offset+2);
      con_len = tvb_get_ntohs(tvb, offset+4);

      proto_tree_add_text(ext_tree_mm, tvb, offset, 1, "DRX: split PG cycle code: %u", drx_split);
      proto_tree_add_text(ext_tree_mm, tvb, offset+1, 1, "DRX: CN specific DRX cycle length coefficient: %u", drx_len);
      proto_tree_add_text(ext_tree_mm, tvb, offset+1, 1, "DRX: split PG cycle on CCCH supported by MS: %s", yesno[drx_ccch]);
      if (non_drx_timer == 0) {
            proto_tree_add_text(ext_tree_mm, tvb, offset+1, 1, "DRX: no non-DRX mode after transfer state");
      } else {
            proto_tree_add_text(ext_tree_mm, tvb, offset+1, 1, "DRX: max sec non-DRX mode after transfer state:  2^%u", non_drx_timer-1);
      }

      proto_tree_add_text(ext_tree_mm, tvb, offset+2, 2, "MS network capability: %u", net_cap);
      proto_tree_add_text(ext_tree_mm, tvb, offset+4, 2, "Container length: %u", con_len);

      if (con_len > 0) {
            trans_id = (tvb_get_guint8(tvb, offset+6) >> 4) & 0x0F;
            proto_tree_add_text(ext_tree_mm, tvb, offset+6, 1, "Transaction identifier: 0x%x", trans_id);
            proto_disc = tvb_get_guint8(tvb, offset+6) & 0x0F;
            proto_tree_add_text(ext_tree_mm, tvb, offset+6, 1, "Protocol discriminator: 0x%x (%s)", proto_disc,
                                val_to_str(proto_disc, mm_proto_disc, "Unknown"));
            message = tvb_get_guint8(tvb, offset+7);
            switch (message) {

            case MM_PROTO_RR_MGMT:
                  proto_tree_add_text(ext_tree_mm, tvb, offset+7, 1, "Message type: 0x%02x (%s)", message,
                                  val_to_str(message, mm_rr_mess, "Unknown"));
                  break;

            case MM_PROTO_MM_NON_GPRS:
                  proto_tree_add_text(ext_tree_mm, tvb, offset+7, 1, "Message type: 0x%02x (%s)", message,
                                  val_to_str(message, mm_mm_mess, "Unknown"));
                  break;

            case MM_PROTO_CALL_CONTROL:
            case MM_PROTO_GROUP_CALL_CONTROL:
            case MM_PROTO_BROADCAST_CALL_CONTROL:
                  proto_tree_add_text(ext_tree_mm, tvb, offset+7, 1, "Message type: 0x%02x (%s)", message,
                                  val_to_str(message, mm_cc_mess, "Unknown"));
                  break;

            case MM_PROTO_MM_GPRS:
                  proto_tree_add_text(ext_tree_mm, tvb, offset+7, 1, "Message type: 0x%02x (%s)", message,
                                  val_to_str(message, mm_gprs_mess, "Unknown"));
                  break;

            default:
                  proto_tree_add_text(ext_tree_mm, tvb, offset+7, 1, "Message type: 0x%02x", message);
                  break;
            }
            /* XXX - dissect additional IEs from GSM L3 message */
      }

      return 3+length;
}

/* Function to extract the value of an hexadecimal octet. Only the lower
 * nybble will be non-zero in the output.
 * */
static guint8 hex2dec (guint8 x)
{
      if ((x >= 'a') && (x <= 'f'))
            x = x - 'a' + 10;
      else if ((x >= 'A') && (x <= 'F'))
            x = x - 'A' + 10;
      else if ((x >= '0') && (x <= '9'))
            x = x - '0';
      else
            x = 0;
      return x;
}

/* Wrapper function to add UTF-8 decoding for QoS attributes in
 * RADIUS messages.
 * */
static guint8 wrapped_tvb_get_guint8( tvbuff_t *tvb, int offset, int type)
{
      if (type == 2)
            return (hex2dec(tvb_get_guint8(tvb, offset)) << 4
                              | hex2dec(tvb_get_guint8(tvb, offset + 1)));
      else
            return tvb_get_guint8(tvb, offset);
}

 /* WARNING : actually length is coded on 2 octets for QoS profile but on 1 octet for PDP Context!
  * so type means length of length :-)
  *
  * WARNING :) type does not mean length of length any more... see below for
  * type = 3!
 */
int
decode_qos_umts(tvbuff_t *tvb, int offset, proto_tree *tree, gchar* qos_str, guint8 type) {

      guint       length;
      guint8            al_ret_priority;
      guint8            delay, reliability, peak, precedence, mean, spare1, spare2, spare3;
      guint8            traf_class, del_order, del_err_sdu;
      guint8            max_sdu_size, max_ul, max_dl;
      guint8            res_ber, sdu_err_ratio;
      guint8            trans_delay, traf_handl_prio;
      guint8            guar_ul, guar_dl;
      proto_tree  *ext_tree_qos;
      proto_item  *te;
      int         mss, mu, md, gu, gd;

      /* Will keep if the input is UTF-8 encoded (as in RADIUS messages).
       * If 1, input is *not* UTF-8 encoded (i.e. each input octet corresponds
       * to one byte to be dissected).
       * If 2, input is UTF-8 encoded (i.e. each *couple* of input octets
       * corresponds to one byte to be dissected)
       * */
      guint8      utf8_type = 1;

      /* In RADIUS messages the QoS has a version field of two octets prepended.
       * As of 29.061 v.3.a.0, there is an hyphen between "Release Indicator" and
       * <release specific QoS IE UTF-8 encoding>. Even if it sounds rather
       * inconsistent and unuseful, I will check hyphen presence here and
       * will signal its presence.
       * */
      guint8      hyphen;

      /* Will keep the value that will be returned
       * */
      int         retval = 0;

      switch (type) {
            case 1:
                  length = tvb_get_guint8 (tvb, offset);
                  te = proto_tree_add_text (tree, tvb, offset, length + 1, "%s", qos_str);
                  ext_tree_qos = proto_item_add_subtree (te, ett_gtp_qos);
                  proto_tree_add_text (ext_tree_qos, tvb, offset, 1, "Length: %u", length);
                  offset++;
                  retval = length + 1;
                  break;
            case 2:
                  length = tvb_get_ntohs (tvb, offset + 1);
                  te = proto_tree_add_text(tree, tvb, offset, length + 3, "%s", qos_str);
                  ext_tree_qos = proto_item_add_subtree (te, ett_gtp_qos);
                  proto_tree_add_text (ext_tree_qos, tvb, offset + 1, 2, "Length: %u", length);
                  offset += 3;            /* +1 because of first 0x86 byte for UMTS QoS */
                  retval = length + 3;
                  break;
            case 3:
                  /* For QoS inside RADIUS Client messages from GGSN */
                  utf8_type = 2;

                  /* The field in the RADIUS message starts one byte before :) */
                  length = tvb_get_guint8 (tvb, offset);
                  te = proto_tree_add_text (tree, tvb, offset - 1, length, "%s", qos_str);

                  ext_tree_qos = proto_item_add_subtree (te, ett_gtp_qos);
                  
                  proto_tree_add_item (ext_tree_qos, hf_gtp_qos_version, tvb, offset + 1, 2, FALSE);

                  /* Hyphen handling */
                  hyphen = tvb_get_guint8(tvb, offset + 3);
                  if (hyphen == ((guint8) '-'))
                  {
                        /* Hyphen is present, put in protocol tree */
                        proto_tree_add_text (ext_tree_qos, tvb, offset + 3, 1, "Hyphen separator: -");
                        offset++; /* "Get rid" of hyphen */
                  }

                  /* Now, we modify offset here and in order to use type later
                   * effectively.*/
                  offset += 2;
                  retval = length + 3;      /* Actually, will be ignored. */
                  break;
            default:
                  /* XXX - what should we do with the length here? */
                  length = 0;
                  retval = 0;
                  ext_tree_qos = NULL;
                  break;
      }

      /* In RADIUS messages there is no allocation-retention priority
       * so I don't need to wrap the following call to tvb_get_guint8
       * */
      al_ret_priority = tvb_get_guint8 (tvb, offset);

      /* All calls are wrapped to take into account the possibility that the
       * input is UTF-8 encoded. If utf8_type is equal to 1, the final value
       * of the offset will be the same as in the previous version of this
       * dissector, and the wrapped function will serve as a dumb wrapper;
       * otherwise, if utf_8_type is 2, the offset is correctly shifted by
       * two bytes for needed shift, and the wrapped function will unencode
       * two values from the input.
       * */
      spare1 = wrapped_tvb_get_guint8(tvb, offset+(1 - 1) * utf8_type + 1, utf8_type) & 0xC0;
      delay = wrapped_tvb_get_guint8(tvb, offset+(1 - 1) * utf8_type + 1, utf8_type) & 0x38;
      reliability = wrapped_tvb_get_guint8(tvb, offset+(1 - 1) * utf8_type + 1, utf8_type) & 0x07;
      peak = wrapped_tvb_get_guint8(tvb, offset+(2 - 1) * utf8_type + 1, utf8_type) & 0xF0;
      spare2 = wrapped_tvb_get_guint8(tvb, offset+(2 - 1) * utf8_type + 1, utf8_type) & 0x08;
      precedence = wrapped_tvb_get_guint8(tvb, offset+(2 - 1) * utf8_type + 1, utf8_type) & 0x07;
      spare3 = wrapped_tvb_get_guint8(tvb, offset+(3 - 1) * utf8_type + 1, utf8_type) & 0xE0;
      mean = wrapped_tvb_get_guint8(tvb, offset+(3 - 1) * utf8_type + 1, utf8_type) & 0x1F;

      /* In RADIUS messages there is no allocation-retention priority */
      if (type != 3)
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_al_ret_priority, tvb, offset, 1, al_ret_priority);

      /* All additions must take care of the fact that QoS fields in RADIUS
       * messages are UTF-8 encoded, so we have to use the same trick as above.
       * */
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_spare1, tvb, offset+(1 - 1) * utf8_type + 1, utf8_type, spare1);
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_delay, tvb, offset+(1 - 1) * utf8_type + 1, utf8_type, delay);
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_reliability, tvb, offset+(1 - 1) * utf8_type + 1, utf8_type, reliability);
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_peak, tvb, offset+(2 - 1) * utf8_type + 1, utf8_type, peak);
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_spare2, tvb, offset+(2 - 1) * utf8_type + 1, utf8_type, spare2);
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_precedence, tvb, offset+(2 - 1) * utf8_type + 1, utf8_type, precedence);
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_spare3, tvb, offset+(3 - 1) * utf8_type + 1, utf8_type, spare3);
      proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_mean, tvb, offset+(3 - 1) * utf8_type + 1, utf8_type, mean);

      if (length > 4) {

            /* See above for the need of wrapping
             * */
            traf_class = wrapped_tvb_get_guint8(tvb, offset+(4 - 1) * utf8_type + 1, utf8_type) & 0xE0;
            del_order = wrapped_tvb_get_guint8(tvb, offset+(4 - 1) * utf8_type + 1, utf8_type) & 0x18;
            del_err_sdu = wrapped_tvb_get_guint8(tvb, offset+(4 - 1) * utf8_type + 1, utf8_type) & 0x07;
            max_sdu_size = wrapped_tvb_get_guint8(tvb, offset+(5 - 1) * utf8_type + 1, utf8_type);
            max_ul = wrapped_tvb_get_guint8(tvb, offset+(6 - 1) * utf8_type + 1, utf8_type);
            max_dl = wrapped_tvb_get_guint8(tvb, offset+(7 - 1) * utf8_type + 1, utf8_type);
            res_ber = wrapped_tvb_get_guint8(tvb, offset+(8 - 1) * utf8_type + 1, utf8_type) & 0xF0;
            sdu_err_ratio = wrapped_tvb_get_guint8(tvb, offset+(8 - 1) * utf8_type + 1, utf8_type) & 0x0F;
            trans_delay = wrapped_tvb_get_guint8(tvb, offset+(9 - 1) * utf8_type + 1, utf8_type) & 0xFC;
            traf_handl_prio = wrapped_tvb_get_guint8(tvb, offset+(9 - 1) * utf8_type + 1, utf8_type) & 0x03;
            guar_ul = wrapped_tvb_get_guint8(tvb, offset+(10 - 1) * utf8_type + 1, utf8_type);
            guar_dl = wrapped_tvb_get_guint8(tvb, offset+(11 - 1) * utf8_type + 1, utf8_type);

            /* See above comments for the changes
             * */
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_traf_class, tvb, offset+(4 - 1) * utf8_type + 1, utf8_type, traf_class);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_del_order, tvb, offset+(4 - 1) * utf8_type + 1, utf8_type, del_order);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_del_err_sdu, tvb, offset+(4 - 1) * utf8_type + 1, utf8_type, del_err_sdu);
            if (max_sdu_size == 0 || max_sdu_size > 150)
                  proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_max_sdu_size, tvb, offset+(5 - 1) * utf8_type + 1, utf8_type, max_sdu_size);
            if (max_sdu_size > 0 && max_sdu_size <= 150) {
                  mss = max_sdu_size*10;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_max_sdu_size, tvb, offset+(5 - 1) * utf8_type + 1, utf8_type, mss, "Maximum SDU size : %u octets", mss);
            }

            if(max_ul == 0 || max_ul == 255)
                  proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_max_ul, tvb, offset+(6 - 1) * utf8_type + 1, utf8_type, max_ul);
            if(max_ul > 0 && max_ul <= 63)
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_max_ul, tvb, offset+(6 - 1) * utf8_type + 1, utf8_type, max_ul, "Maximum bit rate for uplink : %u kbps", max_ul);
            if(max_ul > 63 && max_ul <=127) {
                  mu = 64 + ( max_ul - 64 ) * 8;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_max_ul, tvb, offset+(6 - 1) * utf8_type + 1, utf8_type, mu, "Maximum bit rate for uplink : %u kbps", mu);
            }

            if(max_ul > 127 && max_ul <=254) {
                  mu = 576 + ( max_ul - 128 ) * 64;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_max_ul, tvb, offset+(6 - 1) * utf8_type + 1, utf8_type, mu, "Maximum bit rate for uplink : %u kbps", mu);
            }

            if(max_dl == 0 || max_dl == 255)
                  proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_max_dl, tvb, offset+(7 - 1) * utf8_type + 1, utf8_type, max_dl);
            if(max_dl > 0 && max_dl <= 63)
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_max_dl, tvb, offset+(7 - 1) * utf8_type + 1, utf8_type, max_dl, "Maximum bit rate for downlink : %u kbps", max_dl);
            if(max_dl > 63 && max_dl <=127) {
                  md = 64 + ( max_dl - 64 ) * 8;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_max_dl, tvb, offset+(7 - 1) * utf8_type + 1, utf8_type, md, "Maximum bit rate for downlink : %u kbps", md);
            }
            if(max_dl > 127 && max_dl <=254) {
                  md = 576 + ( max_dl - 128 ) * 64;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_max_dl, tvb, offset+(7 - 1) * utf8_type + 1, utf8_type, md, "Maximum bit rate for downlink : %u kbps", md);
            }

            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_res_ber, tvb, offset+(8 - 1) * utf8_type + 1, utf8_type, res_ber);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_sdu_err_ratio, tvb, offset+(8 - 1) * utf8_type + 1, utf8_type, sdu_err_ratio);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_trans_delay, tvb, offset+(9 - 1) * utf8_type + 1, utf8_type, trans_delay);
            proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_traf_handl_prio, tvb, offset+(9 - 1) * utf8_type + 1, utf8_type, traf_handl_prio);

            if(guar_ul == 0 || guar_ul == 255)
                  proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_guar_ul, tvb, offset+(10 - 1) * utf8_type + 1, utf8_type, guar_ul);
            if(guar_ul > 0 && guar_ul <= 63)
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_guar_ul, tvb, offset+(10 - 1) * utf8_type + 1, utf8_type, guar_ul, "Guaranteed bit rate for uplink : %u kbps", guar_ul);
            if(guar_ul > 63 && guar_ul <=127) {
                  gu = 64 + ( guar_ul - 64 ) * 8;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_guar_ul, tvb, offset+(10 - 1) * utf8_type + 1, utf8_type, gu, "Guaranteed bit rate for uplink : %u kbps", gu);
            }
            if(guar_ul > 127 && guar_ul <=254) {
                  gu = 576 + ( guar_ul - 128 ) * 64;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_guar_ul, tvb, offset+(10 - 1) * utf8_type + 1, utf8_type, gu, "Guaranteed bit rate for uplink : %u kbps", gu);
            }

            if(guar_dl == 0 || guar_dl == 255)
                  proto_tree_add_uint(ext_tree_qos, hf_gtp_qos_guar_dl, tvb, offset+(11 - 1) * utf8_type + 1, utf8_type, guar_dl);
            if(guar_dl > 0 && guar_dl <= 63)
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_guar_dl, tvb, offset+(11 - 1) * utf8_type + 1, utf8_type, guar_dl, "Guaranteed bit rate for downlink : %u kbps", guar_dl);
            if(guar_dl > 63 && guar_dl <=127) {
                  gd = 64 + ( guar_dl - 64 ) * 8;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_guar_dl, tvb, offset+(11 - 1) * utf8_type + 1, utf8_type, gd, "Guaranteed bit rate for downlink : %u kbps", gd);
            }
            if(guar_dl > 127 && guar_dl <=254) {
                  gd = 576 + ( guar_dl - 128 ) * 64;
                  proto_tree_add_uint_format(ext_tree_qos, hf_gtp_qos_guar_dl, tvb, offset+(11 - 1) * utf8_type + 1, utf8_type, gd, "Guaranteed bit rate for downlink : %u kbps", gd);
            }

      }

      return retval;
}

static void
decode_apn(tvbuff_t *tvb, int offset, guint16 length, proto_tree *tree) {

      gchar *apn = NULL;
      guint8      name_len, tmp;

      if (length > 0) {
            name_len = tvb_get_guint8 (tvb, offset);

            if (name_len < 0x20) {
                  apn = tvb_get_string(tvb, offset + 1, length - 1);
                  for (;;) {
                        if (name_len >= length - 1) break;
                        tmp = name_len;
                        name_len = name_len + apn[tmp] + 1;
                        apn[tmp] = '.';
                  }
            } else
                  apn = tvb_get_string(tvb, offset, length);

            proto_tree_add_string (tree, hf_gtp_apn, tvb, offset, length, apn);
            g_free(apn);
      }
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.20
 * UMTS:    29.060 v4.0, chapter 7.7.29
 * TODO:    unify addr functions
 */
static int
decode_gtp_pdp_cntxt(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            ggsn_addr_len, apn_len, trans_id, vaa, order, nsapi, sapi, pdu_send_no, pdu_rec_no, pdp_cntxt_id,
                  pdp_type_org, pdp_type_num, pdp_addr_len;
      guint16           length, sn_down, sn_up, up_flow;
      guint32     addr_ipv4, up_teid, up_teid_cp;
      struct      e_in6_addr addr_ipv6;
      proto_tree  *ext_tree_pdp;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset+1);

      te = proto_tree_add_text(tree, tvb, offset, length+3, val_to_str(GTP_EXT_PDP_CNTXT, gtp_val, "Unknown message"));
      ext_tree_pdp = proto_item_add_subtree(te, ett_gtp_pdp);

      vaa = (tvb_get_guint8(tvb, offset+3) >> 6) & 0x01;
      order = (tvb_get_guint8(tvb, offset+3) >> 4) & 0x01;
      nsapi =  tvb_get_guint8(tvb, offset+3) & 0x0F;
      sapi = tvb_get_guint8(tvb, offset+4) & 0x0F;

      proto_tree_add_text(ext_tree_pdp, tvb, offset+3, 1, "VPLMN address allowed: %s", yesno[vaa]);
      proto_tree_add_text(ext_tree_pdp, tvb, offset+3, 1, "Reordering required: %s", yesno[order]);
      proto_tree_add_text(ext_tree_pdp, tvb, offset+3, 1, "NSAPI: %u", nsapi);
      proto_tree_add_text(ext_tree_pdp, tvb, offset+4, 1, "SAPI: %u", sapi);

      switch (gtp_version) {
            case 0:
                  decode_qos_gprs(tvb, offset+5, ext_tree_pdp, "QoS subscribed", 0);
                  decode_qos_gprs(tvb, offset+8, ext_tree_pdp, "QoS requested", 0);
                  decode_qos_gprs(tvb, offset+11, ext_tree_pdp, "QoS negotiated", 0);
                  offset = offset + 14;
                  break;
            case 1:
                  offset = offset + 5;
                  offset = offset + decode_qos_umts(tvb, offset, ext_tree_pdp, "QoS subscribed", 1);
                  offset = offset + decode_qos_umts(tvb, offset, ext_tree_pdp, "QoS requested", 1);
                  offset = offset + decode_qos_umts(tvb, offset, ext_tree_pdp, "QoS negotiated", 1);
                  break;
            default:
                  break;
      }

      sn_down = tvb_get_ntohs(tvb, offset);
      sn_up = tvb_get_ntohs(tvb, offset+2);
      pdu_send_no = tvb_get_guint8(tvb, offset+4);
      pdu_rec_no = tvb_get_guint8(tvb, offset+5);

      proto_tree_add_text(ext_tree_pdp, tvb, offset, 2, "Sequence number down: %u", sn_down);
      proto_tree_add_text(ext_tree_pdp, tvb, offset+2, 2, "Sequence number up: %u", sn_up);
      proto_tree_add_text(ext_tree_pdp, tvb, offset+4, 1, "Send N-PDU number: %u", pdu_send_no);
      proto_tree_add_text(ext_tree_pdp, tvb, offset+5, 1, "Receive N-PDU number: %u", pdu_rec_no);

      switch (gtp_version) {
            case 0:
                  up_flow = tvb_get_ntohs(tvb, offset+6);
                  proto_tree_add_text(ext_tree_pdp, tvb, offset+6, 2, "Uplink flow label signalling: %u", up_flow);
                  offset = offset + 8;
                  break;
            case 1:
                  up_teid = tvb_get_ntohl(tvb, offset+6);
                  up_teid_cp = tvb_get_ntohl(tvb, offset+10);
                  pdp_cntxt_id = tvb_get_guint8(tvb, offset+14);
                  proto_tree_add_text(ext_tree_pdp, tvb, offset+6, 4, "Uplink TEID: %x", up_teid);
                  proto_tree_add_text(ext_tree_pdp, tvb, offset+10, 4, "Uplink TEID control plane: %x", up_teid_cp);
                  proto_tree_add_text(ext_tree_pdp, tvb, offset+14, 1, "PDP context identifier: %u", pdp_cntxt_id);
                  offset = offset + 15;
                  break;
            default:
                  break;
      }

      pdp_type_org = tvb_get_guint8(tvb, offset) & 0x0F;
      pdp_type_num = tvb_get_guint8(tvb, offset+1);
      pdp_addr_len = tvb_get_guint8(tvb, offset+2);

      proto_tree_add_text(ext_tree_pdp, tvb, offset, 1, "PDP organization: %s", val_to_str(pdp_type_org, pdp_type, "Unknown PDP org"));
      proto_tree_add_text(ext_tree_pdp, tvb, offset+1, 1, "PDP type: %s", val_to_str(pdp_type_num, pdp_org_type, "Unknown PDP type"));
      proto_tree_add_text(ext_tree_pdp, tvb, offset+2, 1, "PDP address length: %u", pdp_addr_len);

      if (pdp_addr_len > 0) {
            switch (pdp_type_num) {
                  case 0x21:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+3, sizeof addr_ipv4);
                        proto_tree_add_text(ext_tree_pdp, tvb, offset+3, 4, "PDP address: %s", ip_to_str((guint8 *)&addr_ipv4));
                        break;
                  case 0x57:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+3, sizeof addr_ipv6);
                        proto_tree_add_text(ext_tree_pdp, tvb, offset+3, 16, "PDP address: %s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                        break;
                  default:
                        break;
            }
      }

      offset = offset + 3 + pdp_addr_len;

      ggsn_addr_len = tvb_get_guint8(tvb, offset);
      proto_tree_add_text(ext_tree_pdp, tvb, offset, 1, "GGSN address length: %u", ggsn_addr_len);

      switch (ggsn_addr_len) {
            case 4:
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+1, sizeof addr_ipv4);
                  proto_tree_add_text(ext_tree_pdp, tvb, offset+1, 4, "GGSN address: %s", ip_to_str((guint8 *)&addr_ipv4));
                  break;
            case 16:
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+1, sizeof addr_ipv6);
                  proto_tree_add_text(ext_tree_pdp, tvb, offset+1, 16, "GGSN address: %s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                  break;
            default:
                  break;
      }

      offset = offset + 1 + ggsn_addr_len;

      if (gtp_version == 1) {

            ggsn_addr_len = tvb_get_guint8(tvb, offset);
            proto_tree_add_text(ext_tree_pdp, tvb, offset, 1, "GGSN 2 address length: %u", ggsn_addr_len);

            switch (ggsn_addr_len) {
                  case 4:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+1, sizeof addr_ipv4);
                        proto_tree_add_text(ext_tree_pdp, tvb, offset+1, 4, "GGSN 2 address: %s", ip_to_str((guint8 *)&addr_ipv4));
                        break;
                  case 16:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+1, sizeof addr_ipv6);
                        proto_tree_add_text(ext_tree_pdp, tvb, offset+1, 16, "GGSN 2 address: %s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                        break;
                  default:
                        break;
            }
            offset = offset + 1 + ggsn_addr_len;

      }

      apn_len = tvb_get_guint8(tvb, offset);
      proto_tree_add_text(ext_tree_pdp, tvb, offset, 1, "APN length: %u", apn_len);
      decode_apn(tvb, offset+1, apn_len, ext_tree_pdp);

      offset = offset + 1 + apn_len;

      trans_id = tvb_get_guint8(tvb, offset);
      proto_tree_add_text(ext_tree_pdp, tvb, offset, 1, "Transaction identifier: %u", trans_id);

      return 3+length;
}

/* GPRS:    9.60, v7.6.0, chapter 7.9.21
 * UMTS:    29.060, v4.0, chapter 7.7.30
 */
static int
decode_gtp_apn(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;
      proto_tree  *ext_tree_apn;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset+1);

      te = proto_tree_add_text (tree, tvb, offset, length+3, val_to_str(GTP_EXT_APN, gtp_val, "Unknown field"));
      ext_tree_apn = proto_item_add_subtree(te, ett_gtp_apn);

      proto_tree_add_text (ext_tree_apn, tvb, offset+1, 2, "APN length : %u", length);
      decode_apn (tvb, offset+3, length, ext_tree_apn);

      return 3+length;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.22
 *          4.08 v. 7.1.2, chapter 10.5.6.3 (p.580)
 * UMTS:    29.060 v4.0, chapter 7.7.31
 *          24.008, v4.2, chapter 10.5.6.3
 */
int
decode_gtp_proto_conf(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree) {

      guint16         length, proto_offset;
      guint16           proto_id;
      guint8          conf, proto_len, cnt = 1;
      tvbuff_t        *next_tvb;
      proto_tree      *ext_tree_proto;
      proto_item      *te;
      gboolean    save_writable;

      length = tvb_get_ntohs(tvb, offset + 1);

      te = proto_tree_add_text(tree, tvb, offset, length + 3, val_to_str(GTP_EXT_PROTO_CONF, gtp_val, "Unknown message"));
      ext_tree_proto = proto_item_add_subtree(te, ett_gtp_proto);

      proto_tree_add_text(ext_tree_proto, tvb, offset + 1, 2, "Length: %u", length);

      if (length < 1) return 3;

      conf = tvb_get_guint8 (tvb, offset + 3) & 0x07;
      proto_tree_add_text (ext_tree_proto, tvb, offset + 3, 1, "Configuration protocol (00000xxx): %u", conf);

      proto_offset = 1;       /* ... 1st byte is conf */
      offset += 4;

      for (;;) {
            if (proto_offset >= length) break;
            proto_id = tvb_get_ntohs (tvb, offset);
            proto_len = tvb_get_guint8 (tvb, offset + 2);
            proto_offset += proto_len + 3;            /* 3 = proto id + length byte */

            if (proto_len > 0) {

                  proto_tree_add_text (ext_tree_proto, tvb, offset, 2, "Protocol %u ID: %s (0x%04x)",
                      cnt, val_to_str(proto_id, ppp_vals, "Unknown"),
                      proto_id);
                  proto_tree_add_text (ext_tree_proto, tvb, offset+2, 1, "Protocol %u length: %u", cnt, proto_len);

                  /*
                   * Don't allow the dissector for the configuration
                   * protocol in question to update the columns - this
                   * is GTP, not PPP.
                   */
                  save_writable = col_get_writable(pinfo->cinfo);
                  col_set_writable(pinfo->cinfo, FALSE);

                  /*
                   * XXX - should we have our own dissector table,
                   * solely for configuration protocols, so that bogus
                   * values don't cause us to dissect the protocol
                   * data as, for example, IP?
                   */
                  next_tvb = tvb_new_subset (tvb, offset + 3, proto_len, proto_len);
                  if (!dissector_try_port(ppp_subdissector_table,
                      proto_id, next_tvb, pinfo, ext_tree_proto)) {
                        call_dissector(data_handle, next_tvb, pinfo,
                            ext_tree_proto);
                  }

                  col_set_writable(pinfo->cinfo, save_writable);
            }

            offset += proto_len + 3;
            cnt++;
      }

      return 3 + length;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.23
 * UMTS:    29.060 v4.0, chapter 7.7.32
 */
static int
decode_gtp_gsn_addr(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint8            addr_type, addr_len;
      guint16           length;
      guint32           addr_ipv4;
      struct      e_in6_addr addr_ipv6;
      proto_tree  *ext_tree_gsn_addr;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset+1);

      te = proto_tree_add_text(tree, tvb, offset, 3+length, "GSN address : ");
      ext_tree_gsn_addr = proto_item_add_subtree(te, ett_gtp_gsn_addr);

      switch (length) {
            case 4:
                  proto_tree_add_text(ext_tree_gsn_addr, tvb, offset+1, 2, "GSN address length : %u", length);
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+3, sizeof addr_ipv4);
                  proto_item_append_text(te, "%s", ip_to_str((guint8 *)&addr_ipv4));
                  proto_tree_add_ipv4(ext_tree_gsn_addr, hf_gtp_gsn_ipv4, tvb, offset+3, 4, addr_ipv4);
                  break;
            case 5:
                  proto_tree_add_text(ext_tree_gsn_addr, tvb, offset+1, 2, "GSN address Information Element length : %u", length);
                  addr_type = tvb_get_guint8(tvb, offset+3) & 0xC0;
                  proto_tree_add_uint(ext_tree_gsn_addr, hf_gtp_gsn_addr_type, tvb, offset+3, 1, addr_type);
                  addr_len = tvb_get_guint8(tvb, offset+3) & 0x3F;
                  proto_tree_add_uint(ext_tree_gsn_addr, hf_gtp_gsn_addr_len, tvb, offset+3, 1, addr_len);
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+4, sizeof addr_ipv4);
                  proto_item_append_text(te, "%s", ip_to_str((guint8 *)&addr_ipv4));
                  proto_tree_add_ipv4(ext_tree_gsn_addr, hf_gtp_gsn_ipv4, tvb, offset+4, 4, addr_ipv4);
                  break;
            case 16:
                  proto_tree_add_text(ext_tree_gsn_addr, tvb, offset+1, 2, "GSN address length : %u", length);
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+3, sizeof addr_ipv6);
                  proto_item_append_text(te, "%s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                  proto_tree_add_ipv6(ext_tree_gsn_addr, hf_gtp_gsn_ipv6, tvb, offset+3, 16, (guint8*)&addr_ipv6);
                  break;
            case 17:
                  proto_tree_add_text(ext_tree_gsn_addr, tvb, offset+1, 2, "GSN address Information Element length : %u", length);
                  addr_type = tvb_get_guint8(tvb, offset+3) & 0xC0;
                  proto_tree_add_uint(ext_tree_gsn_addr, hf_gtp_gsn_addr_type, tvb, offset+3, 1, addr_type);
                  addr_len = tvb_get_guint8(tvb, offset+3) & 0x3F;
                  proto_tree_add_uint(ext_tree_gsn_addr, hf_gtp_gsn_addr_len, tvb, offset+3, 1, addr_len);
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+4, sizeof addr_ipv6);
                  proto_item_append_text(te, "%s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                  proto_tree_add_ipv6(ext_tree_gsn_addr, hf_gtp_gsn_ipv6, tvb, offset+4, 16, (guint8*)&addr_ipv6);
                  break;
            default:
                  proto_item_append_text(te, "unknown type or wrong length");
                  break;
      }

      return 3+length;
}

/* GPRS:    9.60 v7.6.0, chapter 7.9.24
 * UMTS:    29.060 v4.0, chapter 7.7.33
 */
static int
decode_gtp_msisdn(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      const guint8      *msisdn_val;
      gchar       *msisdn_str;
      guint16           length;

      length = tvb_get_ntohs(tvb, offset+1);

      if (length < 1) return 3;

      msisdn_val = tvb_get_ptr(tvb, offset+3, length);
      msisdn_str = msisdn_to_str(msisdn_val, length);

      proto_tree_add_string(tree, hf_gtp_msisdn, tvb, offset, 3+length, msisdn_str);

      return 3+length;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.34
 *          24.008 v4.2, chapter 10.5.6.5
 */
static int
decode_gtp_qos_umts(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      return decode_qos_umts(tvb, offset, tree, "Quality of Service", 2);
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.35
 */
static int
decode_gtp_auth_qui(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      return (1 + decode_quintuplet(tvb, offset+1, tree, 1, 1));

}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.36
 *          24.008 v4.2, chapter 10.5.6.12
 */
static int
decode_gtp_tft(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length, port1, port2, tos;
      guint8            tft_flags, tft_code, no_packet_filters, i, pf_id, pf_eval, pf_len, pf_content_id, proto, spare;
      guint       pf_offset;
      guint32           mask_ipv4, addr_ipv4, ipsec_id, label;
      struct      e_in6_addr addr_ipv6, mask_ipv6;
      proto_tree  *ext_tree_tft, *ext_tree_tft_pf, *ext_tree_tft_flags;
      proto_item  *te, *tee, *tef;

      length = tvb_get_ntohs(tvb, offset+1);

      te = proto_tree_add_text(tree, tvb, offset, 3+length, "Traffic flow template");
      ext_tree_tft = proto_item_add_subtree(te, ett_gtp_tft);

      tft_flags = tvb_get_guint8(tvb, offset+3);
      tft_code = (tft_flags >> 5) & 0x07;
      spare = (tft_flags >> 4) & 0x01;
      no_packet_filters = tft_flags & 0x0F;

      proto_tree_add_text(ext_tree_tft, tvb, offset+1, 2, "TFT length: %u", length);

      tef = proto_tree_add_text (ext_tree_tft, tvb, offset + 3, 1, "TFT flags");
      ext_tree_tft_flags = proto_item_add_subtree (tef, ett_gtp_tft_flags);
      proto_tree_add_uint (ext_tree_tft_flags, hf_gtp_tft_code, tvb, offset + 3, 1, tft_flags);
      proto_tree_add_uint (ext_tree_tft_flags, hf_gtp_tft_spare, tvb, offset + 3, 1, tft_flags);
      proto_tree_add_uint (ext_tree_tft_flags, hf_gtp_tft_number, tvb, offset + 3, 1, tft_flags);

      offset = offset + 4;

      for (i=0;i<no_packet_filters;i++) {

            pf_id = tvb_get_guint8(tvb, offset);

            tee = proto_tree_add_text (ext_tree_tft, tvb, offset, 1, "Packet filter id: %u", pf_id);
            ext_tree_tft_pf = proto_item_add_subtree (tee, ett_gtp_tft_pf);
            offset++;

            if (tft_code != 2) {

                  pf_eval = tvb_get_guint8(tvb, offset);
                  pf_len = tvb_get_guint8(tvb, offset + 1);

                  proto_tree_add_uint (ext_tree_tft_pf, hf_gtp_tft_eval, tvb, offset, 1, pf_eval);
                  proto_tree_add_text (ext_tree_tft_pf, tvb, offset+1, 1, "Content length: %u", pf_len);

                  offset = offset + 2;
                  pf_offset = 0;

                  while (pf_offset < pf_len) {

                        pf_content_id = tvb_get_guint8 (tvb, offset + pf_offset);

                        switch (pf_content_id) {
                              /* address IPv4 and mask = 8 bytes*/
                              case 0x10:
                                    tvb_memcpy (tvb, (guint8 *)&addr_ipv4, offset + pf_offset + 1, sizeof addr_ipv4);
                                    tvb_memcpy (tvb, (guint8 *)&mask_ipv4, offset + pf_offset + 5, sizeof mask_ipv4);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 9, "ID 0x10: IPv4/mask: %s/%s", ip_to_str ((guint8 *)&addr_ipv4), ip_to_str ((guint8 *)&mask_ipv4));
                                    pf_offset = pf_offset + 9;
                                    break;
                              /* address IPv6 and mask = 32 bytes*/
                              case 0x20:
                                    tvb_memcpy (tvb, (guint8 *)&addr_ipv6, offset+pf_offset+1, sizeof addr_ipv6);
                                    tvb_memcpy (tvb, (guint8 *)&mask_ipv6, offset+pf_offset+17, sizeof mask_ipv6);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset+pf_offset, 33, "ID 0x20: IPv6/mask: %s/%s", ip6_to_str ((struct e_in6_addr*)&addr_ipv6), ip6_to_str ((struct e_in6_addr*)&mask_ipv6));
                                    pf_offset = pf_offset + 33;
                                    break;
                              /* protocol identifier/next header type = 1 byte*/
                              case 0x30:
                                    proto = tvb_get_guint8 (tvb, offset + pf_offset + 1);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 2, "ID 0x30: IPv4 protocol identifier/IPv6 next header: %u (%x)", proto, proto);
                                    pf_offset = pf_offset + 2;
                                    break;
                              /* single destination port type = 2 bytes */
                              case 0x40:
                                    port1 = tvb_get_ntohs (tvb, offset + pf_offset + 1);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 3, "ID 0x40: destination port: %u", port1);
                                    pf_offset = pf_offset + 3;
                                    break;
                              /* destination port range type = 4 bytes */
                              case 0x41:
                                    port1 = tvb_get_ntohs (tvb, offset + pf_offset + 1);
                                    port2 = tvb_get_ntohs (tvb, offset + pf_offset + 3);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 5, "ID 0x41: destination port range: %u - %u", port1, port2);
                                    pf_offset = pf_offset + 5;
                                    break;
                              /* single source port type = 2 bytes */
                              case 0x50:
                                    port1 = tvb_get_ntohs (tvb, offset + pf_offset + 1);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 3, "ID 0x50: source port: %u", port1);
                                    pf_offset = pf_offset + 3;
                                    break;
                              /* source port range type = 4 bytes */
                              case 0x51:
                                    port1 = tvb_get_ntohs (tvb, offset + pf_offset + 1);
                                    port2 = tvb_get_ntohs (tvb, offset + pf_offset + 3);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 5, "ID 0x51: source port range: %u - %u", port1, port2);
                                    pf_offset = pf_offset + 5;
                                    break;
                              /* security parameter index type = 4 bytes */
                              case 0x60:
                                    ipsec_id = tvb_get_ntohl (tvb, offset + pf_offset + 1);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 5, "ID 0x60: security parameter index: %x", ipsec_id);
                                    pf_offset = pf_offset + 5;
                                    break;
                              /* type of service/traffic class type = 2 bytes */
                              case 0x70:
                                    tos = tvb_get_ntohs (tvb, offset + pf_offset + 1);
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 2, "ID 0x70: Type of Service/Traffic Class: %u (%x)", tos, tos);
                                    pf_offset = pf_offset + 3;
                                    break;
                              /* flow label type = 3 bytes */
                              case 0x80:
                                    label = tvb_get_ntoh24(tvb, offset + pf_offset + 1) & 0x0FFFFF;
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 4, "ID 0x80: Flow Label: %u (%x)", label, label);
                                    pf_offset = pf_offset + 4;
                                    break;

                              default:
                                    proto_tree_add_text (ext_tree_tft_pf, tvb, offset + pf_offset, 1, "Unknown value: %x ", pf_content_id);
                                    pf_offset++; /* to avoid infinite loop */
                                    break;
                        }
                  }

                  offset = offset + pf_offset;
            }
      }

      return 3 + length;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.37
 *          25.413 v3.4, chapter ???
 */
static int
decode_gtp_target_id(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;

      length = tvb_get_ntohs(tvb, offset + 1);

      proto_tree_add_text(tree, tvb, offset, 3 + length, "Targer Identification");

      return 3 + length;
}


/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.38
 */
static int
decode_gtp_utran_cont(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;

      length = tvb_get_ntohs(tvb, offset + 1);

      proto_tree_add_text(tree, tvb, offset, 3 + length, "UTRAN transparent field");

      return 3 + length;

}


/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.39
 */
static int
decode_gtp_rab_setup(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint32           teid, addr_ipv4;
      guint16           length;
      guint8            nsapi;
      struct      e_in6_addr addr_ipv6;
      proto_tree  *ext_tree_rab_setup;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset + 1);
      nsapi = tvb_get_guint8(tvb, offset + 3) & 0x0F;

      te = proto_tree_add_text(tree, tvb, offset, 3+length, "Radio Access Bearer Setup Information");
      ext_tree_rab_setup = proto_item_add_subtree(te, ett_gtp_rab_setup);

      proto_tree_add_text(ext_tree_rab_setup, tvb, offset+1, 2, "RAB setup length : %u", length);
      proto_tree_add_uint(ext_tree_rab_setup, hf_gtp_nsapi, tvb, offset+3, 1, nsapi);

      if (length > 1) {

            teid = tvb_get_ntohl(tvb, offset + 4);

            proto_tree_add_uint(ext_tree_rab_setup, hf_gtp_teid_data, tvb, offset+4, 4, teid);

            switch (length) {
                  case 12:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+8, sizeof addr_ipv4);
                        proto_tree_add_ipv4(ext_tree_rab_setup, hf_gtp_rnc_ipv4, tvb, offset+8, 4, addr_ipv4);
                        break;
                  case 24:
                        tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+8, sizeof addr_ipv6);
                        proto_tree_add_ipv6(ext_tree_rab_setup, hf_gtp_rnc_ipv6, tvb, offset+8, 16, (guint8 *)&addr_ipv6);
                        break;
                  default:
                        break;
            }
      }

      return 3 + length;
}


/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.40
 */
static int
decode_gtp_hdr_list(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      int         i;
      guint8            length, hdr;
      proto_tree  *ext_tree_hdr_list;
      proto_item  *te;

      length = tvb_get_guint8(tvb, offset + 1);

      te = proto_tree_add_text(tree, tvb, offset, 2+length, "%s", val_to_str(GTP_EXT_HDR_LIST, gtp_val, "Unknown"));
      ext_tree_hdr_list = proto_item_add_subtree(te, ett_gtp_hdr_list);

      proto_tree_add_text(ext_tree_hdr_list, tvb, offset+1, 1, "Number of Extension Header Types in list (i.e., length) : %u", length);

      for(i=0 ; i<length ; i++) {
            hdr = tvb_get_guint8(tvb, offset+2+i);

            proto_tree_add_text(ext_tree_hdr_list, tvb, offset+2+i, 1, "No. %u --> Extension Header Type value : %s (%u)", i+1, val_to_str(hdr, gtp_val, "Unknown Extension Header Type"), hdr);
      }

      return 2 + length;
}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.41
 * TODO:    find TriggerID description
 */
static int
decode_gtp_trigger_id(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;

      length = tvb_get_ntohs(tvb, offset + 1);

      proto_tree_add_text(tree, tvb, offset, 3+length, "%s length : %u", val_to_str(GTP_EXT_TRIGGER_ID, gtp_val, "Unknown"), length);

      return 3 + length;

}

/* GPRS:    not present
 * UMTS:    29.060 v4.0, chapter 7.7.42
 * TODO:    find OMC-ID description
 */
static int
decode_gtp_omc_id(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;

      length = tvb_get_ntohs(tvb, offset + 1);

      proto_tree_add_text(tree, tvb, offset, 3+length, "%s length : %u", val_to_str(GTP_EXT_OMC_ID, gtp_val, "Unknown"), length);

      return 3 + length;

}

/* GPRS:    9.60 v7.6.0, chapter 7.9.25
 * UMTS:    29.060 v4.0, chapter 7.7.43
 */
static int
decode_gtp_chrg_addr(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;
      guint32           addr_ipv4;
      struct      e_in6_addr addr_ipv6;
      proto_tree  *ext_tree_chrg_addr;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset+1);

      te = proto_tree_add_text(tree, tvb, offset, 3+length, "%s : ", val_to_str(GTP_EXT_CHRG_ADDR, gtp_val, "Unknown"));
      ext_tree_chrg_addr = proto_item_add_subtree(te, ett_gtp_chrg_addr);

      proto_tree_add_text(ext_tree_chrg_addr, tvb, offset+1, 2, "%s length : %u", val_to_str(GTP_EXT_CHRG_ADDR, gtp_val, "Unknown"), length);

      switch (length) {
            case 4:
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+3, sizeof addr_ipv4);
                  proto_item_append_text(te, "%s", ip_to_str((guint8 *)&addr_ipv4));
                  proto_tree_add_ipv4 (ext_tree_chrg_addr, hf_gtp_chrg_ipv4, tvb, offset+3, 4, addr_ipv4);
                  break;
            case 16:
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+3, sizeof addr_ipv6);
                  proto_item_append_text(te, "%s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                  proto_tree_add_ipv6 (ext_tree_chrg_addr, hf_gtp_chrg_ipv6, tvb, offset+3, 16, (guint8*)&addr_ipv6);
                  break;
            default:
                  proto_item_append_text(te, "unknown type or wrong length");
                  break;
      }

      return 3 + length;
}

/* GPRS:    12.15
 * UMTS:    33.015
 */
static int
decode_gtp_rel_pack(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length, n, number;
      proto_tree  *ext_tree_rel_pack;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset + 1);

      te = proto_tree_add_text(tree, tvb, offset, 3 + length, "Sequence numbers of released packets IE");
      ext_tree_rel_pack = proto_item_add_subtree(te, ett_gtp_rel_pack);

      n = 0;

      while (n < length) {

            number = tvb_get_ntohs(tvb, offset + 3 + n);
            proto_tree_add_text(ext_tree_rel_pack, tvb, offset + 3 + n, 2, "%u", number);
            n = n + 2;

      }

      return 3 + length;
}

/* GPRS:    12.15
 * UMTS:    33.015
 */
static int
decode_gtp_can_pack(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length, n, number;
      proto_tree  *ext_tree_can_pack;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset + 1);

      te = proto_tree_add_text(tree, tvb, offset, 3 + length, "Sequence numbers of cancelled  packets IE");
      ext_tree_can_pack = proto_item_add_subtree(te, ett_gtp_can_pack);

      n = 0;

      while (n < length) {

            number = tvb_get_ntohs(tvb, offset + 3 + n);
            proto_tree_add_text(ext_tree_can_pack, tvb, offset + 3 + n, 2, "%u", number);
            n = n + 2;
      }

      return 3 + length;
}

/* CDRs dissector */
static int
decode_gtp_data_req(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length, format_ver;
      guint8            no, format;
      proto_tree  *ext_tree;
      proto_item  *te;
      tvbuff_t    *next_tvb;

      te = proto_tree_add_text(tree, tvb, offset, 1, val_to_str(GTP_EXT_DATA_REQ, gtp_val, "Unknown message"));
      ext_tree = proto_item_add_subtree(te, ett_gtp_ext);

      length = tvb_get_ntohs(tvb, offset + 1);
      no = tvb_get_guint8(tvb, offset + 3);
      format = tvb_get_guint8(tvb, offset + 4);
      format_ver = tvb_get_ntohs(tvb, offset + 5);

      proto_tree_add_text(ext_tree, tvb, offset+1, 2, "Length: %u", length);
      proto_tree_add_text(ext_tree, tvb, offset+3, 1, "Number of data records: %u", no);
      proto_tree_add_text(ext_tree, tvb, offset+4, 1, "Data record format: %u", format);
      proto_tree_add_text(ext_tree, tvb, offset+5, 2, "Data record format version: %u", format_ver);
      
      if (gtpcdr_handle) {
            next_tvb = tvb_new_subset (tvb, offset, -1, -1);
            call_dissector (gtpcdr_handle, next_tvb, pinfo, tree);
      }
      else
            proto_tree_add_text (tree, tvb, offset, 0, "Data");

      return 3+length;
}

/* GPRS:    12.15
 * UMTS:    33.015
 */
static int
decode_gtp_data_resp(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length, n, number;
      proto_tree  *ext_tree_data_resp;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset + 1);

      te = proto_tree_add_text(tree, tvb, offset, 3 + length, "Requests responded");
      ext_tree_data_resp = proto_item_add_subtree(te, ett_gtp_data_resp);

      n = 0;

      while (n < length) {

            number = tvb_get_ntohs(tvb, offset + 3 + n);
            proto_tree_add_text(ext_tree_data_resp, tvb, offset + 3 + n, 2, "%u", number);
            n = n + 2;

      }

      return 3 + length;

}

/* GPRS:    12.15
 * UMTS:    33.015
 */
static int
decode_gtp_node_addr(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length;
      guint32           addr_ipv4;
      struct      e_in6_addr addr_ipv6;
      proto_tree  *ext_tree_node_addr;
      proto_item  *te;

      length = tvb_get_ntohs(tvb, offset+1);

      te = proto_tree_add_text(tree, tvb, offset, 3+length, "Node address: ");
      ext_tree_node_addr = proto_item_add_subtree(te, ett_gtp_node_addr);

      proto_tree_add_text (ext_tree_node_addr, tvb, offset+1, 2, "Node address length: %u", length);

      switch (length) {
            case 4:
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv4, offset+3, sizeof addr_ipv4);
                  proto_item_append_text(te, "%s", ip_to_str((guint8 *)&addr_ipv4));
                  proto_tree_add_ipv4 (ext_tree_node_addr, hf_gtp_node_ipv4, tvb, offset+3, 4, addr_ipv4);
                  break;
            case 16:
                  tvb_memcpy(tvb, (guint8 *)&addr_ipv6, offset+3, sizeof addr_ipv6);
                  proto_item_append_text(te, "%s", ip6_to_str((struct e_in6_addr*)&addr_ipv6));
                  proto_tree_add_ipv6 (ext_tree_node_addr, hf_gtp_node_ipv6, tvb, offset+3, 16, (guint8*)&addr_ipv6);
                  break;
            default:
                  proto_item_append_text(te, "unknown type or wrong length");
                  break;
      }

      return 3 + length;

}

/* GPRS:    9.60 v7.6.0, chapter 7.9.26
 * UMTS:    29.060 v4.0, chapter 7.7.44
 */
static int
decode_gtp_priv_ext(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      guint16           length, ext_id;
      proto_tree  *ext_tree_priv_ext;
      proto_item  *te;

      te = proto_tree_add_text(tree, tvb, offset, 1, val_to_str(GTP_EXT_PRIV_EXT, gtp_val, "Unknown message"));
      ext_tree_priv_ext = proto_item_add_subtree(te, ett_gtp_ext);

      length = tvb_get_ntohs(tvb, offset+1);
      if (length >= 2) {
            ext_id = tvb_get_ntohs(tvb, offset+3);
            proto_tree_add_uint(ext_tree_priv_ext, hf_gtp_ext_id, tvb, offset+3, 2, ext_id);

            /*
             * XXX - is this always a text string?  Or should it be
             * displayed as hex data?
             */
            if (length > 2)
                  proto_tree_add_item(ext_tree_priv_ext, hf_gtp_ext_val, tvb, offset+5, length-2, FALSE);
      }

      return 3+length;
}

static int
decode_gtp_unknown(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) {

      proto_tree_add_text(tree, tvb, offset, 1, "Unknown extension header");

      return tvb_length_remaining(tvb, offset);
}

static void
dissect_gtp (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
      struct _gtp_hdr   gtp_hdr;
      proto_tree  *gtp_tree, *flags_tree;
      proto_item  *ti, *tf;
      int         i, offset, length, gtp_prime, checked_field, mandatory;
      int         seq_no, flow_label;
      guint8            pdu_no, next_hdr = 0, ext_hdr_val;
      const guint8      *tid_val;
      gchar       *tid_str;
      guint32           teid;
      tvbuff_t    *next_tvb;
      guint8            sub_proto, acfield_len = 0, control_field;
      
      if (check_col(pinfo->cinfo, COL_PROTOCOL))
            col_set_str(pinfo->cinfo, COL_PROTOCOL, "GTP");
      if (check_col(pinfo->cinfo, COL_INFO))
            col_clear(pinfo->cinfo, COL_INFO);
      
      tvb_memcpy(tvb, (guint8 *)&gtp_hdr, 0, 4);
      
      if (!(gtp_hdr.flags & 0x10))
            gtp_prime = 1;
      else
            gtp_prime = 0;
      
      switch ((gtp_hdr.flags >> 5) & 0x07) {
            case 0: 
                  gtp_version = 0;
                  break;
            case 1: 
                  gtp_version = 1;
                  break;
            default: 
                  gtp_version = 1;
                  break;
      }

      if (check_col(pinfo->cinfo, COL_INFO))
            col_add_str(pinfo->cinfo, COL_INFO, val_to_str(gtp_hdr.message, message_type, "Unknown"));
      
      if (tree) {
            ti = proto_tree_add_item (tree, proto_gtp, tvb, 0, -1, FALSE);
            gtp_tree = proto_item_add_subtree(ti, ett_gtp);
            
            tf = proto_tree_add_uint (gtp_tree, hf_gtp_flags, tvb, 0, 1, gtp_hdr.flags);
            flags_tree = proto_item_add_subtree (tf, ett_gtp_flags);
            
            proto_tree_add_uint (flags_tree, hf_gtp_flags_ver, tvb, 0, 1, gtp_hdr.flags);
            proto_tree_add_uint (flags_tree, hf_gtp_flags_pt, tvb, 0, 1, gtp_hdr.flags);
            
            switch (gtp_version) {
                  case 0:
                        proto_tree_add_uint (flags_tree, hf_gtp_flags_spare1, tvb, 0, 1, gtp_hdr.flags);
                        proto_tree_add_boolean (flags_tree, hf_gtp_flags_snn, tvb, 0, 1, gtp_hdr.flags);
                        break;
                  case 1:
                        proto_tree_add_uint (flags_tree, hf_gtp_flags_spare2, tvb, 0, 1, gtp_hdr.flags);
                        proto_tree_add_boolean (flags_tree, hf_gtp_flags_e, tvb, 0, 1, gtp_hdr.flags);
                        proto_tree_add_boolean (flags_tree, hf_gtp_flags_s, tvb, 0, 1, gtp_hdr.flags);
                        proto_tree_add_boolean (flags_tree, hf_gtp_flags_pn, tvb, 0, 1, gtp_hdr.flags);
                        break;
                  default:
                        break;
            }
                        
            proto_tree_add_uint (gtp_tree, hf_gtp_message_type, tvb, 1, 1, gtp_hdr.message);
            
            gtp_hdr.length = g_ntohs (gtp_hdr.length);
            proto_tree_add_uint (gtp_tree, hf_gtp_length, tvb, 2, 2, gtp_hdr.length);
            
            offset = 4;
            
            if (gtp_prime) {
                  seq_no = tvb_get_ntohs (tvb, offset);
                  proto_tree_add_uint (gtp_tree, hf_gtp_seq_number, tvb, offset, 2, seq_no);
                  offset += 2;
            } else
            switch (gtp_version) {
                  case 0:
                        seq_no = tvb_get_ntohs (tvb, offset);
                        proto_tree_add_uint (gtp_tree, hf_gtp_seq_number, tvb, offset, 2, seq_no);
                        offset += 2;
                  
                        flow_label = tvb_get_ntohs (tvb, offset);
                        proto_tree_add_uint (gtp_tree, hf_gtp_flow_label, tvb, offset, 2, flow_label);
                        offset += 2;
                  
                        pdu_no = tvb_get_guint8 (tvb, offset);
                        proto_tree_add_uint (gtp_tree, hf_gtp_sndcp_number, tvb, offset, 1, pdu_no);
                        offset += 4;
                        
                        tid_val = tvb_get_ptr(tvb, offset, 8);
                        tid_str = id_to_str (tid_val);
                        proto_tree_add_string (gtp_tree, hf_gtp_tid, tvb, offset, 8, tid_str);
                        offset += 8;
                        break;                  
                  case 1:
                        teid = tvb_get_ntohl (tvb, offset);
                        proto_tree_add_uint (gtp_tree, hf_gtp_teid, tvb, offset, 4, teid);
                        offset += 4;

                        if (gtp_hdr.flags & 0x07) {
                              seq_no = tvb_get_ntohs (tvb, offset);
                              proto_tree_add_uint (gtp_tree, hf_gtp_seq_number, tvb, offset, 2, seq_no);
                              offset += 2;
                              
                              pdu_no = tvb_get_guint8 (tvb, offset);
                              proto_tree_add_uint (gtp_tree, hf_gtp_npdu_number, tvb, offset, 1, pdu_no);
                              offset++;
                              
                              next_hdr = tvb_get_guint8 (tvb, offset);
                              proto_tree_add_uint (gtp_tree, hf_gtp_next, tvb, offset, 1, next_hdr);
                              if (!next_hdr)
                                    offset++;
                        }
                        break;
                  default:
                        break;
            }
            
            
            if (gtp_hdr.message != GTP_MSG_TPDU) {
                  proto_tree_add_text(gtp_tree, tvb, 0, 0, "[--- end of GTP header, beginning of extension headers ---]");
                  length = tvb_length (tvb);
                  mandatory = 0;          /* check order of GTP fields against ETSI */
                  for (;;) {
                        if (offset >= length) 
                              break;
                        if (next_hdr) {
                              ext_hdr_val = next_hdr;
                              next_hdr = 0;
                        }
                        else
                              ext_hdr_val = tvb_get_guint8 (tvb, offset);
                        if (gtp_etsi_order) {
                              checked_field = check_field_presence (gtp_hdr.message, ext_hdr_val , (int *)&mandatory);
                              switch (checked_field) {
                                    case -2: proto_tree_add_text (gtp_tree, tvb, 0, 0, "[WARNING] message not found");
                                           break;
                                    case -1: proto_tree_add_text (gtp_tree, tvb, 0, 0, "[WARNING] field not present");
                                           break;
                                    case 0:  break;
                                    default: proto_tree_add_text (gtp_tree, tvb, offset, 1, "[WARNING] wrong next field, should be: %s", val_to_str(checked_field, gtp_val, "Unknown extension field"));
                                           break;
                              }
                        }

                        i = -1;
                        while (gtpopt[++i].optcode) 
                              if (gtpopt[i].optcode == ext_hdr_val) 
                                    break;
                        offset = offset + (*gtpopt[i].decode)(tvb, offset, pinfo, gtp_tree);
                  }
            }
      }
      
      if ((gtp_hdr.message == GTP_MSG_TPDU) && gtp_tpdu) {

            if (gtp_prime)
                  offset = 6;
            else
            if (gtp_version == 1) {
                  if (gtp_hdr.flags & 0x07)  {
                        offset = 11;
                        if (tvb_get_guint8 (tvb, offset) == 0)
                              offset++;
                  }
                  else 
                        offset = 8;
            }
            else
                  offset = 20;

            sub_proto = tvb_get_guint8 (tvb, offset);

            if ((sub_proto >= 0x45) &&  (sub_proto <= 0x4e)) {
                  /* this is most likely an IPv4 packet
                   * we can exclude 0x40 - 0x44 because the minimum header size is 20 octets
                   * 0x4f is excluded because PPP protocol type "IPv6 header compression"
                   * with protocol field compression is more likely than a plain IPv4 packet with 60 octet header size */
                  
                  next_tvb = tvb_new_subset (tvb, offset, -1, -1);
                  call_dissector(ip_handle, next_tvb, pinfo, tree);
                  
            } else
                if ((sub_proto & 0xf0) == 0x60){
                  /* this is most likely an IPv6 packet */
                  next_tvb = tvb_new_subset (tvb, offset, -1, -1);
                  call_dissector (ipv6_handle, next_tvb, pinfo, tree);
            } else {
                  /* this seems to be a PPP packet */

                  if (sub_proto == 0xff) {
                        /* this might be an address field, even it shouldn't be here */
                        control_field = tvb_get_guint8 (tvb, offset + 1);
                        if (control_field == 0x03)
                              /* now we are pretty sure that address and control field are mistakenly inserted -> ignore it for PPP dissection */
                              acfield_len = 2;
                  }

                  next_tvb = tvb_new_subset (tvb, offset + acfield_len, -1, -1);
                  call_dissector (ppp_handle, next_tvb, pinfo, tree);
            }

            if (check_col(pinfo->cinfo, COL_PROTOCOL))
                  col_append_str_gtp(pinfo->cinfo, COL_PROTOCOL, "GTP");
      }
}

static const true_false_string yes_no_tfs = {
      "yes" ,
      "no"
};

void
proto_register_gtp(void)
{
      static hf_register_info hf_gtp[] = {
            { &hf_gtp_apn, { "APN", "gtp.apn", FT_STRING, BASE_DEC, NULL, 0, "Access Point Name", HFILL }},
            { &hf_gtp_cause, { "Cause ", "gtp.cause", FT_UINT8, BASE_DEC, VALS(cause_type), 0, "Cause of operation", HFILL }},
            { &hf_gtp_chrg_char, { "Charging characteristics", "gtp.chrg_char", FT_UINT16, BASE_DEC, NULL, 0, "Charging characteristics", HFILL }},
            { &hf_gtp_chrg_char_s, { "Spare", "gtp.chrg_char_s", FT_UINT16,   BASE_DEC, NULL, GTP_MASK_CHRG_CHAR_S, "Spare", HFILL }},
            { &hf_gtp_chrg_char_n, { "Normal charging", "gtp.chrg_char_n", FT_UINT16, BASE_DEC, NULL, GTP_MASK_CHRG_CHAR_N, "Normal charging", HFILL }},
            { &hf_gtp_chrg_char_p, { "Prepaid charging", "gtp.chrg_char_p", FT_UINT16, BASE_DEC, NULL, GTP_MASK_CHRG_CHAR_P, "Prepaid charging", HFILL }},
            { &hf_gtp_chrg_char_f, { "Flat rate charging", "gtp.chrg_char_f", FT_UINT16, BASE_DEC, NULL, GTP_MASK_CHRG_CHAR_F, "Flat rate charging", HFILL }},
            { &hf_gtp_chrg_char_h, { "Hot billing charging", "gtp.chrg_char_h", FT_UINT16, BASE_DEC, NULL, GTP_MASK_CHRG_CHAR_H, "Hot billing charging", HFILL }},
            { &hf_gtp_chrg_char_r, { "Reserved", "gtp.chrg_char_r", FT_UINT16, BASE_DEC, NULL, GTP_MASK_CHRG_CHAR_R, "Reserved", HFILL }},
            { &hf_gtp_chrg_id, { "Charging ID", "gtp.chrg_id", FT_UINT32, BASE_HEX, NULL, 0, "Charging ID", HFILL }},
            { &hf_gtp_chrg_ipv4, { "CG address IPv4", "gtp.chrg_ipv4", FT_IPv4, BASE_DEC, NULL, 0, "Charging Gateway address IPv4", HFILL }},
            { &hf_gtp_chrg_ipv6, { "CG address IPv6", "gtp.chrg_ipv6", FT_IPv6, BASE_HEX, NULL, 0, "Charging Gateway address IPv6", HFILL }},
            { &hf_gtp_ext_flow_label, { "Flow Label Data I", "gtp.ext_flow_label", FT_UINT16, BASE_HEX, NULL, 0, "Flow label data", HFILL }},
            { &hf_gtp_ext_id, { "Extension identifier", "gtp.ext_id", FT_UINT16, BASE_DEC, NULL, 0, "Extension Identifier", HFILL }},
            { &hf_gtp_ext_val, { "Extension value", "gtp.ext_val", FT_STRING, BASE_DEC, NULL, 0, "Extension Value", HFILL }},
            { &hf_gtp_flags, { "Flags", "gtp.flags", FT_UINT8, BASE_HEX, NULL, 0, "Ver/PT/Spare...", HFILL }},
            { &hf_gtp_flags_ver, { "Version", "gtp.flags.version", FT_UINT8, BASE_DEC, VALS(ver_types), GTP_VER_MASK, "GTP Version", HFILL }},
            { &hf_gtp_flags_pt, { "Protocol type",    "gtp.flags.payload", FT_UINT8, BASE_DEC, NULL, GTP_PT_MASK, "Protocol Type", HFILL }},
            { &hf_gtp_flags_spare1, { "Reserved", "gtp.flags.reserved", FT_UINT8, BASE_DEC, NULL, GTP_SPARE1_MASK, "Reserved (shall be sent as '111' )", HFILL }},
            { &hf_gtp_flags_snn, { "Is SNDCP N-PDU included?", "gtp.flags.snn", FT_BOOLEAN, 8, TFS(&yes_no_tfs), GTP_SNN_MASK, "Is SNDCP N-PDU LLC Number included? (1 = yes, 0 = no)", HFILL }},
            { &hf_gtp_flags_spare2, { "Reserved", "gtp.flags.reserved", FT_UINT8, BASE_DEC, NULL, GTP_SPARE2_MASK, "Reserved (shall be sent as '1' )", HFILL }},
            { &hf_gtp_flags_e, { "Is Next Extension Header present?", "gtp.flags.e", FT_BOOLEAN, 8, TFS(&yes_no_tfs), GTP_E_MASK, "Is Next Extension Header present? (1 = yes, 0 = no)", HFILL }},
            { &hf_gtp_flags_s, { "Is Sequence Number present?", "gtp.flags.s", FT_BOOLEAN, 8, TFS(&yes_no_tfs), GTP_S_MASK, "Is Sequence Number present? (1 = yes, 0 = no)", HFILL }},
            { &hf_gtp_flags_pn, { "Is N-PDU number present?", "gtp.flags.pn", FT_BOOLEAN, 8, TFS(&yes_no_tfs), GTP_PN_MASK, "Is N-PDU number present? (1 = yes, 0 = no)", HFILL }},
            { &hf_gtp_flow_ii, { "Flow Label Data II ", "gtp.flow_ii", FT_UINT16, BASE_DEC, NULL, 0, "Downlink flow label data", HFILL }},
            { &hf_gtp_flow_label, { "Flow label", "gtp.flow_label", FT_UINT16, BASE_HEX, NULL, 0, "Flow label", HFILL }},
            { &hf_gtp_flow_sig, { "Flow label Signalling", "gtp.flow_sig", FT_UINT16, BASE_HEX, NULL, 0, "Flow label signalling", HFILL }},
            { &hf_gtp_gsn_addr_len, { "GSN Address Length", "gtp.gsn_addr_len", FT_UINT8, BASE_DEC, NULL, GTP_EXT_GSN_ADDR_LEN_MASK, "GSN Address Length", HFILL }},
            { &hf_gtp_gsn_addr_type, { "GSN Address Type", "gtp.gsn_addr_type", FT_UINT8, BASE_DEC, VALS(gsn_addr_type), GTP_EXT_GSN_ADDR_TYPE_MASK, "GSN Address Type", HFILL }},
            { &hf_gtp_gsn_ipv4, { "GSN address IPv4", "gtp.gsn_ipv4", FT_IPv4, BASE_DEC, NULL, 0, "GSN address IPv4", HFILL }},
            { &hf_gtp_gsn_ipv6, { "GSN address IPv6", "gtp.gsn_ipv6", FT_IPv6, BASE_DEC, NULL, 0, "GSN address IPv6", HFILL }},     
            { &hf_gtp_imsi, { "IMSI", "gtp.imsi", FT_STRING, BASE_DEC, NULL, 0, "International Mobile Subscriber Identity number", HFILL }},
            { &hf_gtp_length, { "Length", "gtp.length", FT_UINT16, BASE_DEC, NULL, 0, "Length (i.e. number of octets after TID or TEID)", HFILL }},
            { &hf_gtp_map_cause, { "MAP cause", "gtp.map_cause", FT_UINT8, BASE_DEC, VALS(map_cause_type), 0, "MAP cause", HFILL }},
            { &hf_gtp_message_type, { "Message Type", "gtp.message", FT_UINT8, BASE_HEX, VALS(message_type), 0x0, "GTP Message Type", HFILL }},
            { &hf_gtp_ms_reason, { "MS not reachable reason", "gtp.ms_reason", FT_UINT8, BASE_DEC, VALS(ms_not_reachable_type), 0, "MS Not Reachable Reason", HFILL }},
            { &hf_gtp_ms_valid, { "MS validated", "gtp.ms_valid", FT_BOOLEAN, BASE_NONE,NULL, 0, "MS validated", HFILL }},
            { &hf_gtp_msisdn, { "MSISDN", "gtp.msisdn", FT_STRING, BASE_DEC, NULL, 0, "MS international PSTN/ISDN number", HFILL }},
            { &hf_gtp_next, { "Next extension header type", "gtp.next", FT_UINT8, BASE_HEX, NULL, 0, "Next Extension Header Type", HFILL }},
            { &hf_gtp_node_ipv4, { "Node address IPv4", "gtp.node_ipv4", FT_IPv4, BASE_DEC, NULL, 0, "Recommended node address IPv4", HFILL }},
            { &hf_gtp_node_ipv6, { "Node address IPv6", "gtp.node_ipv6", FT_IPv6, BASE_HEX, NULL, 0, "Recommended node address IPv6", HFILL }},
            { &hf_gtp_npdu_number, { "N-PDU Number", "gtp.npdu_number", FT_UINT8, BASE_HEX, NULL, 0, "N-PDU Number", HFILL }},
            { &hf_gtp_nsapi, { "NSAPI", "gtp.nsapi", FT_UINT8, BASE_DEC, NULL, 0, "Network layer Service Access Point Identifier", HFILL }},
            { &hf_gtp_qos_version, { "Version", "gtp.qos_version", FT_STRING, BASE_DEC, NULL, 0, "Version of the QoS Profile", HFILL }},
            { &hf_gtp_qos_spare1, { "Spare", "gtp.qos_spare1", FT_UINT8, BASE_DEC, NULL, GTP_EXT_QOS_SPARE1_MASK, "Spare (shall be sent as '00' )", HFILL }},
            { &hf_gtp_qos_delay, { "QoS delay", "gtp.qos_delay", FT_UINT8, BASE_DEC, VALS(qos_delay_type), GTP_EXT_QOS_DELAY_MASK, "Quality of Service Delay Class", HFILL }},
            { &hf_gtp_qos_reliability, { "QoS reliability", "gtp.qos_reliabilty", FT_UINT8, BASE_DEC, VALS(qos_reliability_type), GTP_EXT_QOS_RELIABILITY_MASK, "Quality of Service Reliability Class", HFILL }},
            { &hf_gtp_qos_peak, { "QoS peak", "gtp.qos_peak", FT_UINT8, BASE_DEC, VALS(qos_peak_type), GTP_EXT_QOS_PEAK_MASK, "Quality of Service Peak Throughput", HFILL }},
            { &hf_gtp_qos_spare2, { "Spare", "gtp.qos_spare2",FT_UINT8, BASE_DEC, NULL, GTP_EXT_QOS_SPARE2_MASK, "Spare (shall be sent as 0)", HFILL }},
            { &hf_gtp_qos_precedence, { "QoS precedence", "gtp.qos_precedence", FT_UINT8, BASE_DEC, VALS(qos_precedence_type), GTP_EXT_QOS_PRECEDENCE_MASK, "Quality of Service Precedence Class", HFILL }},
            { &hf_gtp_qos_spare3, { "Spare", "gtp.qos_spare3", FT_UINT8, BASE_DEC, NULL, GTP_EXT_QOS_SPARE3_MASK, "Spare (shall be sent as '000' )", HFILL }},
            { &hf_gtp_qos_mean, { "QoS mean", "gtp.qos_mean", FT_UINT8, BASE_DEC, VALS(qos_mean_type), GTP_EXT_QOS_MEAN_MASK, "Quality of Service Mean Throughput", HFILL }},
            { &hf_gtp_qos_al_ret_priority, { "Allocation/Retention priority ","gtp.qos_al_ret_priority", FT_UINT8, BASE_DEC, NULL, 0, "Allocation/Retention Priority", HFILL }},
            { &hf_gtp_qos_traf_class, { "Traffic class", "gtp.qos_traf_class", FT_UINT8, BASE_DEC, VALS(qos_traf_class), GTP_EXT_QOS_TRAF_CLASS_MASK, "Traffic Class", HFILL }},
            { &hf_gtp_qos_del_order, { "Delivery order", "gtp.qos_del_order", FT_UINT8, BASE_DEC, VALS(qos_del_order), GTP_EXT_QOS_DEL_ORDER_MASK, "Delivery Order", HFILL }},
            { &hf_gtp_qos_del_err_sdu, { "Delivery of erroneous SDU", "gtp.qos_del_err_sdu", FT_UINT8, BASE_DEC, VALS(qos_del_err_sdu), GTP_EXT_QOS_DEL_ERR_SDU_MASK, "Delivery of Erroneous SDU", HFILL }},
            { &hf_gtp_qos_max_sdu_size, { "Maximum SDU size", "gtp.qos_max_sdu_size", FT_UINT8, BASE_DEC, VALS(qos_max_sdu_size), 0, "Maximum SDU size", HFILL }},
            { &hf_gtp_qos_max_ul, { "Maximum bit rate for uplink",      "gtp.qos_max_ul", FT_UINT8, BASE_DEC, VALS(qos_max_ul), 0, "Maximum bit rate for uplink", HFILL }},
            { &hf_gtp_qos_max_dl, { "Maximum bit rate for downlink", "gtp.qos_max_dl", FT_UINT8, BASE_DEC, VALS(qos_max_dl), 0, "Maximum bit rate for downlink", HFILL }},
            { &hf_gtp_qos_res_ber, { "Residual BER", "gtp.qos_res_ber", FT_UINT8, BASE_DEC, VALS(qos_res_ber), GTP_EXT_QOS_RES_BER_MASK, "Residual Bit Error Rate", HFILL }},
            { &hf_gtp_qos_sdu_err_ratio, { "SDU Error ratio", "gtp.qos_sdu_err_ratio", FT_UINT8, BASE_DEC, VALS(qos_sdu_err_ratio), GTP_EXT_QOS_SDU_ERR_RATIO_MASK, "SDU Error Ratio", HFILL }},
            { &hf_gtp_qos_trans_delay, { "Transfer delay",  "gtp.qos_trans_delay", FT_UINT8, BASE_DEC, VALS(qos_trans_delay), GTP_EXT_QOS_TRANS_DELAY_MASK, "Transfer Delay", HFILL }},
            { &hf_gtp_qos_traf_handl_prio, { "Traffic handling priority", "gtp.qos_traf_handl_prio", FT_UINT8, BASE_DEC, VALS(qos_traf_handl_prio), GTP_EXT_QOS_TRAF_HANDL_PRIORITY_MASK, "Traffic Handling Priority", HFILL }},
            { &hf_gtp_qos_guar_ul, { "Guaranteed bit rate for uplink", "gtp.qos_guar_ul", FT_UINT8,   BASE_DEC, VALS(qos_guar_ul), 0, "Guaranteed bit rate for uplink", HFILL }},
            { &hf_gtp_qos_guar_dl, { "Guaranteed bit rate for downlink", "gtp.qos_guar_dl",     FT_UINT8, BASE_DEC, VALS(qos_guar_dl), 0, "Guaranteed bit rate for downlink", HFILL }},
            { &hf_gtp_pkt_flow_id, { "Packet Flow ID", "gtp.pkt_flow_id", FT_UINT8, BASE_DEC, NULL, 0, "Packet Flow ID", HFILL }},
            { &hf_gtp_ptmsi, { "P-TMSI", "gtp.ptmsi", FT_UINT32, BASE_HEX, NULL, 0, "Packet-Temporary Mobile Subscriber Identity", HFILL }},
            { &hf_gtp_ptmsi_sig, { "P-TMSI Signature", "gtp.ptmsi_sig", FT_UINT24, BASE_HEX, NULL, 0, "P-TMSI Signature", HFILL }},
            { &hf_gtp_rab_gtpu_dn, { "Downlink GTP-U seq number", "gtp.rab_gtp_dn", FT_UINT16, BASE_DEC, NULL, 0, "Downlink GTP-U sequence number", HFILL }},
            { &hf_gtp_rab_gtpu_up, { "Uplink GTP-U seq number", "gtp.rab_gtp_up", FT_UINT16, BASE_DEC, NULL, 0, "Uplink GTP-U sequence number", HFILL }},
            { &hf_gtp_rab_pdu_dn, { "Downlink next PDCP-PDU seq number", "gtp.rab_pdu_dn", FT_UINT8, BASE_DEC, NULL, 0, "Downlink next PDCP-PDU sequence number", HFILL }},
            { &hf_gtp_rab_pdu_up, { "Uplink next PDCP-PDU seq number", "gtp.rab_pdu_up", FT_UINT8, BASE_DEC, NULL, 0, "Uplink next PDCP-PDU sequence number", HFILL }},
            { &hf_gtp_rai_mcc, { "MCC", "gtp.mcc", FT_UINT16, BASE_DEC, NULL, 0, "Mobile Country Code", HFILL }},
            { &hf_gtp_rai_mnc, { "MNC", "gtp.mnc", FT_UINT8, BASE_DEC, NULL, 0, "Mobile Network Code", HFILL }},
            { &hf_gtp_rai_rac, { "RAC", "gtp.rac", FT_UINT8, BASE_DEC, NULL, 0, "Routing Area Code", HFILL }},
            { &hf_gtp_rai_lac, { "LAC", "gtp.lac", FT_UINT16, BASE_DEC, NULL, 0, "Location Area Code", HFILL }},
            { &hf_gtp_ranap_cause, { "RANAP cause", "gtp.ranap_cause", FT_UINT8, BASE_DEC, VALS(ranap_cause_type), 0, "RANAP cause", HFILL }},
            { &hf_gtp_recovery, { "Recovery", "gtp.recovery", FT_UINT8, BASE_DEC, NULL, 0, "Restart counter", HFILL }},
            { &hf_gtp_reorder, { "Reordering required","gtp.reorder", FT_BOOLEAN, BASE_NONE,NULL, 0, "Reordering required", HFILL }},
            { &hf_gtp_rnc_ipv4, { "RNC address IPv4", "gtp.rnc_ipv4", FT_IPv4, BASE_DEC, NULL, 0, "Radio Network Controller address IPv4", HFILL }},
            { &hf_gtp_rnc_ipv6, { "RNC address IPv6", "gtp.rnc_ipv6", FT_IPv6, BASE_HEX, NULL, 0, "Radio Network Controller address IPv6", HFILL }},
            { &hf_gtp_rp, { "Radio Priority", "gtp.rp", FT_UINT8, BASE_DEC, NULL, GTPv1_EXT_RP_MASK, "Radio Priority for uplink tx", HFILL }},
            { &hf_gtp_rp_nsapi, { "NSAPI in Radio Priority", "gtp.rp_nsapi", FT_UINT8, BASE_DEC, NULL, GTPv1_EXT_RP_NSAPI_MASK, "Network layer Service Access Point Identifier in Radio Priority", HFILL }},
            { &hf_gtp_rp_sms, { "Radio Priority SMS", "gtp.rp_sms",     FT_UINT8, BASE_DEC, NULL, 0, "Radio Priority for MO SMS", HFILL }},
            { &hf_gtp_rp_spare, { "Reserved", "gtp.rp_spare", FT_UINT8, BASE_DEC, NULL, GTPv1_EXT_RP_SPARE_MASK, "Spare bit", HFILL }},         
            { &hf_gtp_sel_mode, { "Selection mode", "gtp.sel_mode", FT_UINT8, BASE_DEC, VALS(sel_mode_type), 0, "Selection Mode", HFILL }},
            { &hf_gtp_seq_number, { "Sequence number", "gtp.seq_number", FT_UINT16, BASE_HEX, NULL, 0, "Sequence Number", HFILL }},
            { &hf_gtp_sndcp_number, { "SNDCP N-PDU LLC Number", "gtp.sndcp_number", FT_UINT8, BASE_HEX, NULL, 0, "SNDCP N-PDU LLC Number", HFILL }},
            { &hf_gtp_tear_ind, { "Teardown Indicator", "gtp.tear_ind", FT_BOOLEAN, BASE_NONE,NULL, 0, "Teardown Indicator", HFILL }},
            { &hf_gtp_teid, { "TEID", "gtp.teid", FT_UINT32, BASE_HEX, NULL, 0, "Tunnel Endpoint Identifier", HFILL }},
            { &hf_gtp_teid_cp, { "TEID Control Plane", "gtp.teid_cp", FT_UINT32, BASE_HEX, NULL, 0, "Tunnel Endpoint Identifier Control Plane", HFILL }},
            { &hf_gtp_teid_data, { "TEID Data I", "gtp.teid_data", FT_UINT32, BASE_HEX, NULL, 0, "Tunnel Endpoint Identifier Data I", HFILL }},
            { &hf_gtp_teid_ii, { "TEID Data II", "gtp.teid_ii", FT_UINT32, BASE_HEX, NULL, 0, "Tunnel Endpoint Identifier Data II", HFILL }},
            { &hf_gtp_tft_code, { "TFT operation code", "gtp.tft_code", FT_UINT8, BASE_DEC, VALS (tft_code_type), GTPv1_TFT_CODE_MASK, "TFT operation code", HFILL }},
            { &hf_gtp_tft_spare, { "TFT spare bit",   "gtp.tft_spare", FT_UINT8, BASE_DEC, NULL, GTPv1_TFT_SPARE_MASK, "TFT spare bit", HFILL }},
            { &hf_gtp_tft_number, { "Number of packet filters", "gtp.tft_number", FT_UINT8, BASE_DEC, NULL, GTPv1_TFT_NUMBER_MASK, "Number of packet filters", HFILL }},
            { &hf_gtp_tft_eval, { "Evaluation precedence", "gtp.tft_eval", FT_UINT8, BASE_DEC, NULL, 0, "Evaluation precedence", HFILL }},
            { &hf_gtp_tid, { "TID", "gtp.tid", FT_STRING, BASE_DEC, NULL, 0, "Tunnel Identifier", HFILL }},
            { &hf_gtp_tlli, { "TLLI", "gtp.tlli", FT_UINT32, BASE_HEX, NULL, 0, "Temporary Logical Link Identity", HFILL }},
            { &hf_gtp_tr_comm, { "Packet transfer command", "gtp.tr_comm", FT_UINT8, BASE_DEC, VALS (tr_comm_type), 0, "Packat transfer command", HFILL }},
            { &hf_gtp_trace_ref, { "Trace reference", "gtp.trace_ref", FT_UINT16, BASE_HEX, NULL, 0, "Trace reference", HFILL }},
            { &hf_gtp_trace_type, { "Trace type", "gtp.trace_type", FT_UINT16, BASE_HEX, NULL, 0, "Trace type", HFILL }},
            { &hf_gtp_unknown, { "Unknown data (length)",   "gtp.unknown", FT_UINT16, BASE_DEC, NULL, 0, "Unknown data", HFILL }},
            { &hf_gtp_user_addr_pdp_org, { "PDP type organization", "gtp.user_addr_pdp_org", FT_UINT8, BASE_DEC, VALS(pdp_org_type), 0, "PDP type organization", HFILL }},
            { &hf_gtp_user_addr_pdp_type, { "PDP type number", "gtp.user_addr_pdp_type", FT_UINT8, BASE_HEX, VALS (pdp_type), 0, "PDP type", HFILL }},
            { &hf_gtp_user_ipv4, { "End user address IPv4", "gtp.user_ipv4", FT_IPv4, BASE_DEC, NULL, 0, "End user address IPv4", HFILL }},
            { &hf_gtp_user_ipv6, { "End user address IPv6", "gtp.user_ipv6", FT_IPv6, BASE_HEX, NULL, 0, "End user address IPv6", HFILL }},           
      };
      
      static gint *ett_gtp_array[] = {
            &ett_gtp,
            &ett_gtp_flags,
            &ett_gtp_ext,
            &ett_gtp_rai,
            &ett_gtp_qos,
            &ett_gtp_auth_tri,
            &ett_gtp_flow_ii,
            &ett_gtp_rab_cntxt,
            &ett_gtp_rp,
            &ett_gtp_pkt_flow_id,
            &ett_gtp_chrg_char,
            &ett_gtp_user,
            &ett_gtp_mm,
            &ett_gtp_trip,
            &ett_gtp_quint,
            &ett_gtp_pdp,
            &ett_gtp_apn,
            &ett_gtp_proto,
            &ett_gtp_gsn_addr,
            &ett_gtp_tft,
            &ett_gtp_tft_pf,
            &ett_gtp_tft_flags,
            &ett_gtp_rab_setup,
            &ett_gtp_hdr_list,
            &ett_gtp_chrg_addr,
            &ett_gtp_node_addr,
            &ett_gtp_rel_pack,
            &ett_gtp_can_pack,
            &ett_gtp_data_resp,
            &ett_gtp_priv_ext,
      };

      module_t    *gtp_module;

      proto_gtp = proto_register_protocol ("GPRS Tunneling Protocol", "GTP", "gtp");
      proto_register_field_array (proto_gtp, hf_gtp, array_length (hf_gtp));
      proto_register_subtree_array (ett_gtp_array, array_length (ett_gtp_array));
      
      gtp_module = prefs_register_protocol(proto_gtp, proto_reg_handoff_gtp);

      prefs_register_uint_preference(gtp_module, "v0_port", "GTPv0 port", "GTPv0 port (default 3386)", 10, &g_gtpv0_port);
      prefs_register_uint_preference(gtp_module, "v1c_port", "GTPv1 control plane (GTP-C) port", "GTPv1 control plane port (default 2123)", 10, &g_gtpv1c_port);
      prefs_register_uint_preference(gtp_module, "v1u_port", "GTPv1 user plane (GTP-U) port", "GTPv1 user plane port (default 2152)", 10, &g_gtpv1u_port);
      prefs_register_bool_preference(gtp_module, "dissect_tpdu", "Dissect T-PDU", "Dissect T-PDU", &gtp_tpdu);
      prefs_register_obsolete_preference (gtp_module, "v0_dissect_cdr_as");
      prefs_register_obsolete_preference (gtp_module, "v0_check_etsi");
      prefs_register_obsolete_preference (gtp_module, "v1_check_etsi");
      prefs_register_bool_preference (gtp_module, "check_etsi", "Compare GTP order with ETSI", "GTP ETSI order", &gtp_etsi_order);
      prefs_register_obsolete_preference(gtp_module, "ppp_reorder");

      register_dissector("gtp", dissect_gtp, proto_gtp);
}

void
proto_reg_handoff_gtp(void)
{
      static int Initialized = FALSE;
      static dissector_handle_t gtp_handle;

      if (!Initialized) {
            gtp_handle = find_dissector("gtp");
            ppp_subdissector_table = find_dissector_table("ppp.protocol");
            Initialized = TRUE;
      } else {
            dissector_delete ("udp.port", gtpv0_port, gtp_handle);
            dissector_delete ("tcp.port", gtpv0_port, gtp_handle);
            dissector_delete ("udp.port", gtpv1c_port, gtp_handle);
            dissector_delete ("tcp.port", gtpv1c_port, gtp_handle);
            dissector_delete ("udp.port", gtpv1u_port, gtp_handle);
            dissector_delete ("tcp.port", gtpv1u_port, gtp_handle);
      }

      gtpv0_port = g_gtpv0_port;
      gtpv1c_port = g_gtpv1c_port;
      gtpv1u_port = g_gtpv1u_port;

      dissector_add ("udp.port", g_gtpv0_port, gtp_handle);
      dissector_add ("tcp.port", g_gtpv0_port, gtp_handle);
      dissector_add ("udp.port", g_gtpv1c_port, gtp_handle);
      dissector_add ("tcp.port", g_gtpv1c_port, gtp_handle);
      dissector_add ("udp.port", g_gtpv1u_port, gtp_handle);
      dissector_add ("tcp.port", g_gtpv1u_port, gtp_handle);

      ip_handle = find_dissector("ip");
        ipv6_handle = find_dissector("ipv6");
      ppp_handle = find_dissector("ppp");
      data_handle = find_dissector("data");
      gtpcdr_handle = find_dissector("gtpcdr");
}

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