/* packet-gmr1_dtap.c

 *

 * Routines for GMR-1 DTAP dissection in wireshark.

 * Copyright (c) 2011 Sylvain Munaut <tnt@246tNt.com>

 *

 * References:

 *  [1] ETSI TS 101 376-4-8 V1.3.1 - GMR-1 04.008

 *  [2] ETSI TS 101 376-4-8 V2.2.1 - GMPRS-1 04.008

 *  [3] ETSI TS 101 376-4-8 V3.1.1 - GMR-1 3G 44.008

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

#include "config.h"

#include <epan/packet.h>

#include "packet-gmr1_common.h"

void proto_register_gmr1_dtap(void);

void proto_reg_handoff_gmr1_dtap(void);

/* GMR-1 DTAP proto */

static int proto_gmr1_dtap;

static int hf_gmr1_dtap_protocol_discriminator;

static int hf_gmr1_dtap_message_elements;

/* GMR-1 DTAP sub tree */

static int ett_gmr1_dtap;

static int ett_gmr1_pd;

/* Handoffs */

static dissector_handle_t gsm_dtap_handle;

static dissector_handle_t dtap_handle;

static int

dissect_gmr1_dtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)

{

  uint32_t len, offset;

  gmr1_msg_func_t msg_func;

  const char *msg_str;

  int ett_tree;

  int hf_idx;

  proto_item *dtap_item = NULL/*, *pd_item = NULL*/;

  proto_tree *dtap_tree = NULL/*, *pd_tree = NULL*/;

  uint32_t oct[2];

  uint8_t pd;

  /* Scan init */

  len = tvb_captured_length(tvb);

  offset = 0;

  /* Protocol descriptor */

  oct[0] = tvb_get_uint8(tvb, offset++);

  if ((oct[0] & GMR1_PD_EXT_MSK) == GMR1_PD_EXT_VAL)

    pd = oct[0] & 0xff;

  else

    pd = oct[0] & 0x0f;

  /* HACK: Quick delegation hack to GSM */

  if (pd != GMR1_PD_RR) {

    call_dissector(gsm_dtap_handle, tvb, pinfo, tree);

    return tvb_captured_length(tvb);

  }

  /* Fill up some info */

  col_append_str(pinfo->cinfo, COL_INFO, " (DTAP) ");

  col_append_fstr(pinfo->cinfo, COL_INFO, "(%s) ",

    val_to_str(pinfo->pool, pd, gmr1_pd_short_vals, "Unknown (%u)"));

  /* Get message parameters */

  oct[1] = tvb_get_uint8(tvb, offset);

  gmr1_get_msg_params((gmr1_pd_e)pd, oct[1], &msg_str, &ett_tree, &hf_idx, &msg_func);

  /* Create protocol tree */

  if (msg_str == NULL)

  {

    dtap_item = proto_tree_add_protocol_format(

      tree, proto_gmr1_dtap, tvb, 0, len,

      "GMR-1 DTAP - Message Type (0x%02x)", oct[1]);

    dtap_tree = proto_item_add_subtree(dtap_item, ett_gmr1_dtap);

    col_append_fstr(pinfo->cinfo, COL_INFO, "Message Type (0x%02x) ", oct[1]);

  }

  else

  {

    dtap_item = proto_tree_add_protocol_format(

      tree, proto_gmr1_dtap, tvb, 0, -1,

      "GMR-1 DTAP - %s", msg_str);

    dtap_tree = proto_item_add_subtree(dtap_item, ett_gmr1_dtap);

    col_append_fstr(pinfo->cinfo, COL_INFO, "%s ", msg_str);

  }

  /* Start over */

  offset = 0;

  /* Protocol discriminator item */

  /*pd_item =*/ proto_tree_add_uint(

    dtap_tree, hf_gmr1_dtap_protocol_discriminator, tvb, 0, 1, pd);

  /*pd_tree = proto_item_add_subtree(pd_item, ett_gmr1_pd);*/

    /* Move on */

  offset++;

  /* Message type - [1] 11.4 */

  proto_tree_add_uint_format(

    dtap_tree, hf_idx, tvb, offset, 1, oct[1],

    "Message Type: %s", msg_str ? msg_str : "(Unknown)"

  );

  offset++;

  /* Decode elements */

  if (msg_func) {

    (*msg_func)(tvb, dtap_tree, pinfo, offset, len - offset);

  } else {

    proto_tree_add_item(dtap_tree, hf_gmr1_dtap_message_elements, tvb, offset, len - offset, ENC_NA);

  }

  /* Done ! */

  return tvb_captured_length(tvb);

}

void

proto_register_gmr1_dtap(void)

{

  static hf_register_info hf[] = {

    { &hf_gmr1_dtap_protocol_discriminator,

      { "Protocol Discriminator", "gmr1.dtap.protocol_discriminator",

      FT_UINT8, BASE_DEC, VALS(gmr1_pd_vals), 0x0,

      NULL, HFILL }

    },

    { &hf_gmr1_dtap_message_elements,

      { "Message elements", "gmr1.dtap.message_elements",

      FT_BYTES, BASE_NONE, NULL, 0x0,

      NULL, HFILL }

    },

  };

  static int *ett[] = {

    &ett_gmr1_dtap,

    &ett_gmr1_pd,

  };

  /* Setup protocol subtree array */

  proto_register_subtree_array(ett, array_length(ett));

  /* Register the protocol name and field description */

  proto_gmr1_dtap = proto_register_protocol("GEO-Mobile Radio (1) DTAP", "GMR-1 DTAP", "gmr1.dtap");

  proto_register_field_array(proto_gmr1_dtap, hf, array_length(hf));

  /* Register dissector */

  dtap_handle = register_dissector("gmr1_dtap", dissect_gmr1_dtap, proto_gmr1_dtap);

}

void

proto_reg_handoff_gmr1_dtap(void)

{

  dissector_add_uint("lapsat.sapi", 0 , dtap_handle); /* LAPSat: CC/RR/MM */

  dissector_add_uint("lapsat.sapi", 3 , dtap_handle); /* LAPSat: SMS/SS */

  gsm_dtap_handle = find_dissector_add_dependency("gsm_a_dtap", proto_gmr1_dtap);

}

/*

 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html

 *

 * Local variables:

 * c-basic-offset: 8

 * tab-width: 8

 * indent-tabs-mode: t

 * End:

 *

 * vi: set shiftwidth=8 tabstop=8 noexpandtab:

 * :indentSize=8:tabSize=8:noTabs=false:

 */