/* packet-pdc.c

 * Routines for PDC dissection

 * Copyright 2014, Antony Bridle <antony.bridle@nats.co.uk>

 *

 * 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-tcp.h"

void proto_register_pdc(void);

void proto_reg_handoff_pdc(void);

/* PDC version */

#define PDC_VERSION 2

#define SIMPDU  1

#define RSMPDU  2

#define DRMPDU  3

#define DTMPDU  4

#define ADMPDU  5

#define EDMPDU  6

#define AKMPDU  8

/*Variable length Parameter Codes*/

#define PARAM_CODE_VERSION  2

#define PARAM_CODE_REFERENCES 3

#define PARAM_CODE_TRANSPORT  4

/* required for the TCP split packet combining */

#define PDC_MSG_SIZE_FIELD_LENGTH 2 /* minimum amount of data to find out how big the split packet should be when recombined */

#define FRAME_HEADER_LEN 8

/* global handle for our dissector */

static dissector_handle_t pdc_tcp_handle;

/* global handle for calling asterix decoder if required */

static dissector_handle_t asterix_handle;

static int      proto_pdc;

/*HF Declarations*/

static int hf_pdc_len;

static int hf_pdc_mpdu_code;

static int hf_pdc_credit;

static int hf_pdc_simpdu_state;

static int hf_pdc_yr_admu_nr;

static int hf_pdc_akmpdu_mns;

static int hf_pdc_akmpdu_cdt;

static int hf_pdc_simpdu_var;

static int hf_pdc_simpdu_var_len;

static int hf_pdc_simpdu_param;

static int hf_pdc_simpdu_var_version;

static int hf_pdc_simpdu_var_REFSRC;

static int hf_pdc_simpdu_var_REFDEST;

static int hf_pdc_simpdu_var_TSEL;

static int hf_pdc_drmpdu_abort;

static int hf_pdc_drmpdu_reason;

static int hf_pdc_drmpdu_mode;

static int hf_pdc_drmpdu_init;

static int hf_pdc_dtmpdu_user_size;

static int hf_pdc_admpdu_admpdunr;

static int hf_pdc_admpdu_size;

/*Tree Declarations*/

static int ett_pdc;

static int ett_pdc_simpdu_var;

/*Value String Declarations*/

static const value_string valstr_simpdu_state[] = {

  { 1, "Operational" },

  { 2, "Standby" },

  { 3, "Master" },

  { 4, "Slave" },

  { 5, "Single" },

  { 0, NULL }

};

static const value_string valstr_simpdu_param[] = {

  { 2, "Version Number" },

  { 3, "References" },

  { 4, "Transport Selector" },

  { 0, NULL }

};

static const value_string valstr_mpdus[] = {

  { 1, "State Information" },

  { 2, "Request State" },

  { 3, "Disconnect Request" },

  { 4, "Data" },

  { 5, "Acknowledged Data" },

  { 6, "Expedited Data" },

  { 8, "Data Acknowledgement" },

  { 0, NULL }

};

static const value_string valstr_drmpdu_abort[] = {

  { 0, "Orderly Release" },

  { 1, "Abortive Release" },

  { 0, NULL }

};

static const value_string valstr_drmpdu_mode[] = {

  { 0, "Node Shutdown" },

  { 7, "PDC Release"},

  { 0, NULL }

};

static const value_string valstr_drmpdu_initatior[] = {

  { 0, "Server" },

  { 15, "Client"},

  { 0, NULL }

};

static const value_string valstr_drmpdu_reason[] = {

  { 0, "Reason Not Specified" },

  { 1, "Normal Disconnect Initiated by the MS-User" },

  { 2, "Protocol Error" },

  { 3, "Connection Request Refused" },

  { 4, "The Remote Operational MS Entity Does Not Respond" },

  { 5, "The Protocol Version Is Not Supported" },

  { 6, "Mismatched References" },

  { 0, NULL }

};

/* start of functions here */

static int dissect_simpdu(tvbuff_t *tvb, proto_tree *tree, uint16_t offset, uint8_t lenIndicator)

{

  int     bytesProcessed;

  uint8_t     paramCode;

  proto_item *simpduItem;

  proto_tree *simpduVarTree;

  proto_tree *simpduVarTree1;

  bytesProcessed = 0;

  /*Add the Credit allocation*/

  proto_tree_add_item(tree, hf_pdc_credit, tvb, offset, 1, ENC_BIG_ENDIAN);

  bytesProcessed += 1;

  /*Add the State*/

  proto_tree_add_item(tree, hf_pdc_simpdu_state, tvb, offset + bytesProcessed , 1, ENC_BIG_ENDIAN);

  bytesProcessed += 1;

  /*Add the YR-ADMU-NR*/

  proto_tree_add_item(tree, hf_pdc_yr_admu_nr, tvb, offset + bytesProcessed , 4, ENC_BIG_ENDIAN);

  bytesProcessed += 4;

  /*Determine what's in the variable part*/

  if (lenIndicator > 7)

  {

    /*Add the Variable Length Tree*/

    simpduItem = proto_tree_add_item (tree, hf_pdc_simpdu_var, tvb, offset + bytesProcessed, lenIndicator - 7, ENC_NA);

    simpduVarTree = proto_item_add_subtree (simpduItem, ett_pdc_simpdu_var);

    while ((offset + bytesProcessed) < ( lenIndicator + 1 ))

    {

      /*Get the parameter code*/

      paramCode  = tvb_get_uint8(tvb, offset + bytesProcessed);

      simpduItem = proto_tree_add_item (simpduVarTree, hf_pdc_simpdu_param, tvb, offset + bytesProcessed,      1, ENC_BIG_ENDIAN);

      simpduVarTree1 = proto_item_add_subtree (simpduItem, ett_pdc_simpdu_var);

      bytesProcessed += 1;

      switch (paramCode)

      {

      case PARAM_CODE_VERSION:

        proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_len,     tvb, offset + bytesProcessed,     1, ENC_BIG_ENDIAN);

        proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_version, tvb, offset + bytesProcessed + 1, 1, ENC_BIG_ENDIAN);

        bytesProcessed += 2;

        break;

      case PARAM_CODE_REFERENCES:

        proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_len,     tvb, offset + bytesProcessed,     1, ENC_BIG_ENDIAN);

        proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_REFSRC,  tvb, offset + bytesProcessed + 1, 2, ENC_BIG_ENDIAN);

        proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_REFDEST, tvb, offset + bytesProcessed + 3, 2, ENC_BIG_ENDIAN);

        bytesProcessed += 5;

        break;

      case PARAM_CODE_TRANSPORT:

        proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_len,     tvb, offset + bytesProcessed,     1, ENC_BIG_ENDIAN);

        proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_TSEL,    tvb, offset + bytesProcessed + 1, 2, ENC_BIG_ENDIAN);

        bytesProcessed += 3;

        break;

      }

    } /* end of whileloop */

  }

  return (bytesProcessed);

}

static int dissect_rsmpdu(void)

{

  return 0;

}

static int dissect_drmpdu(tvbuff_t *tvb, proto_tree *tree, uint16_t offset)

{

  /*DR-MPDU*/

  proto_tree_add_item(tree, hf_pdc_drmpdu_abort,  tvb, offset,     1, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_pdc_drmpdu_mode,   tvb, offset,     1, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_pdc_drmpdu_init,   tvb, offset,     1, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_pdc_drmpdu_reason, tvb, offset + 1, 1, ENC_BIG_ENDIAN);

  return 2;

}

#if (PDC_VERSION == 2)

static int dissect_admpdu(tvbuff_t *tvb, proto_tree *parent_tree, proto_tree *tree, uint16_t offset, packet_info *pinfo)

{

  uint16_t    userDataLen;

  uint16_t    returnLen;

  tvbuff_t *asterixTVB;

  /*Add the ad*/

  proto_tree_add_item(tree, hf_pdc_admpdu_admpdunr, tvb, offset, 4, ENC_BIG_ENDIAN);

  offset += 4;

  proto_tree_add_item(tree, hf_pdc_admpdu_size, tvb, offset, 2, ENC_BIG_ENDIAN);

  /* length of user data field */

  userDataLen = tvb_get_ntohs(tvb, offset);

  offset += 2;

  returnLen = userDataLen + 6;

  asterixTVB = tvb_new_subset_length(tvb, offset, userDataLen);

  if (asterix_handle != NULL)

    call_dissector(asterix_handle, asterixTVB, pinfo, parent_tree);

  return (returnLen);

}

#else

static int dissect_admpdu(tvbuff_t *tvb, proto_tree *parent_tree _U_, proto_tree *tree, uint16_t offset, packet_info *pinfo _U_)

{

  /*Add the ad*/

  proto_tree_add_item(tree, hf_pdc_admpdu_admpdunr, tvb, offset, 4, ENC_BIG_ENDIAN);

  return 2;

}

#endif

#if (PDC_VERSION == 2)

static int dissect_dtmpdu(tvbuff_t *tvb, proto_tree *parent_tree, proto_tree *tree, uint16_t offset, packet_info *pinfo)

{

  uint16_t    userDataLen;

  uint16_t    returnLen;

  tvbuff_t *asterixTVB;

  proto_tree_add_item(tree, hf_pdc_dtmpdu_user_size, tvb, offset, 2, ENC_BIG_ENDIAN);

  /* length of user data field */

  userDataLen = tvb_get_ntohs(tvb, 2);

  returnLen  = userDataLen + 2;

  asterixTVB = tvb_new_subset_length(tvb, offset + 2, userDataLen);

  if (asterix_handle != NULL)

    call_dissector(asterix_handle, asterixTVB, pinfo, parent_tree);

  return (returnLen);

}

#else

static int dissect_dtmpdu(tvbuff_t *tvb _U_, proto_tree *parent_tree _U_, proto_tree *tree _U_, uint16_t offset _U_, packet_info *pinfo _U_)

{

  return 2;

}

#endif

#if (PDC_VERSION == 2)

static int dissect_edmpdu(tvbuff_t *tvb, proto_tree *parent_tree, proto_tree *tree, uint16_t offset, packet_info *pinfo)

{

  uint16_t    userDataLen;

  uint16_t    returnLen;

  tvbuff_t *asterixTVB;

  proto_tree_add_item(tree, hf_pdc_dtmpdu_user_size, tvb, offset, 2, ENC_BIG_ENDIAN);

  /* length of user data field */

  userDataLen = tvb_get_ntohs(tvb, 2);

  returnLen   = userDataLen + 2;

  asterixTVB  = tvb_new_subset_length(tvb, offset + 2, userDataLen);

  if (asterix_handle != NULL)

    call_dissector(asterix_handle, asterixTVB, pinfo, parent_tree);

  return (returnLen);

}

#else

static int dissect_edmpdu(tvbuff_t *tvb _U_, proto_tree *parent_tree _U_, proto_tree *tree _U_, uint16_t offset _U_, packet_info *pinfo _U_)

{

  return 2;

}

#endif

static int dissect_akmpdu(tvbuff_t *tvb, proto_tree *tree, uint16_t offset)

{

  proto_tree_add_item(tree, hf_pdc_akmpdu_mns, tvb, offset,     2, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_pdc_akmpdu_cdt, tvb, offset,     2, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_pdc_yr_admu_nr, tvb, offset + 2, 4, ENC_BIG_ENDIAN);

  return (6);

}

static int dissect_pdc_packet(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo)

{

  unsigned      i = 0;

  uint8_t     len_indicator;

  uint8_t     mpduCode;

  uint16_t      length;

  proto_item *pdcPacketItem;

  proto_tree *pdcPacketTree;

  length = 0;

  /*Get the length indictor and the MPDU Code*/

  len_indicator  = tvb_get_uint8 (tvb, i);

  mpduCode       = tvb_get_uint8 (tvb, i + 1);

  length        += 2;

  /*Add the PDC Tree*/

  pdcPacketItem = proto_tree_add_item (tree, proto_pdc, tvb, i, len_indicator + 1, ENC_NA);

  pdcPacketTree = proto_item_add_subtree (pdcPacketItem, ett_pdc);

  /*Add the Length and packet type*/

  proto_tree_add_item(pdcPacketTree, hf_pdc_len, tvb, i, 1, ENC_BIG_ENDIAN);

  proto_tree_add_item(pdcPacketTree, hf_pdc_mpdu_code, tvb, i + 1, 1, ENC_BIG_ENDIAN);

  /*Call the correct dissecting function*/

  switch (mpduCode)

  {

  case SIMPDU:

    length += dissect_simpdu(tvb, pdcPacketTree, length, len_indicator);

    col_set_str(pinfo->cinfo, COL_INFO, "SIMPDU");

    break;

  case RSMPDU:

    length += dissect_rsmpdu();

    col_set_str(pinfo->cinfo, COL_INFO, "RSMPDU");

    break;

  case DRMPDU:

    length += dissect_drmpdu(tvb, pdcPacketTree, length);

    col_set_str(pinfo->cinfo, COL_INFO, "DRMPDU");

    break;

  case DTMPDU:

    length += dissect_dtmpdu(tvb, tree, pdcPacketTree, length, pinfo);

    col_set_str(pinfo->cinfo, COL_INFO, "DTMPDU");

    break;

  case ADMPDU:

    length += dissect_admpdu(tvb, tree, pdcPacketTree, length, pinfo);

    col_set_str(pinfo->cinfo, COL_INFO, "ADMPDU");

    break;

  case EDMPDU:

    length += dissect_edmpdu(tvb, tree, pdcPacketTree, length, pinfo);

    col_set_str(pinfo->cinfo, COL_INFO, "EDMPDU");

    break;

  case AKMPDU:

    length += dissect_akmpdu(tvb, pdcPacketTree, length);

    col_set_str(pinfo->cinfo, COL_INFO, "AKMPDU");

    break;

  default:

    break;

  };

  return (length);  /* XXX: returned length ignored by caller: Remove keeping track of data processed ?         */

        /*      col_set_str() could then be done separately with 'if (tree)' around the dissection */

}

/* Actual dissector bits and bytes done here */

static int dissect_pdc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)

{

  /*Set the Column*/

  col_set_str(pinfo->cinfo, COL_PROTOCOL, "PDC");

  col_clear(pinfo->cinfo, COL_INFO);

  dissect_pdc_packet(tvb, tree, pinfo);

  return tvb_reported_length(tvb);

}

/* function to provide TCP split packet combiner with size of packet */

static unsigned get_pdc_message_len(packet_info *pinfo _U_, tvbuff_t *tvb,

                                 int offset, void *data _U_)

{

  unsigned  size;

  unsigned  extra;

  uint8_t mpdu_type;

  mpdu_type = tvb_get_uint8(tvb, offset+1);

  switch (mpdu_type)

  {

  case SIMPDU:

    size  = tvb_get_uint8(tvb, offset);

    extra = 1;

    break;

  case RSMPDU:

    size  = tvb_get_uint8(tvb, offset);

    extra = 1;

    break;

  case DRMPDU:

    size  = tvb_get_uint8(tvb, offset);

    extra = 1;

    break;

  case DTMPDU:

    size  = tvb_get_ntohs(tvb, offset+2);

    extra = 4;

    break;

  case ADMPDU:

    size  = tvb_get_ntohs(tvb, offset+6);

    extra = 8;

    break;

  case EDMPDU:

    size  = tvb_get_uint8(tvb, offset);

    extra = 1;

    break;

  case AKMPDU:

    size  = tvb_get_uint8(tvb, offset)+1;

    extra = 0;

    break;

  default:

    size  = 0;

    extra = 0;

  }

  return size + extra;

}

/* top level call to recombine split tcp packets */

static int tcp_dissect_pdc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)

{

  uint8_t mpdu_type;

  uint8_t minimum_bytes;

  mpdu_type = tvb_get_uint8(tvb,1);

  switch (mpdu_type)

  {

  case SIMPDU:

    minimum_bytes = 2;

    break;

  case RSMPDU:

    minimum_bytes = 2;

    break;

  case DRMPDU:

    minimum_bytes = 2;

    break;

  case DTMPDU:

    minimum_bytes = 4;

    break;

  case ADMPDU:

    minimum_bytes = 8;

    break;

  case EDMPDU:

    minimum_bytes = 2;

    break;

  case AKMPDU:

    minimum_bytes = 2;

    break;

  default:

    minimum_bytes = 2;

    break;

  }

  tcp_dissect_pdus(tvb, pinfo, tree, true, minimum_bytes, get_pdc_message_len, dissect_pdc, NULL);

  return tvb_captured_length(tvb);

}

void proto_register_pdc(void)

{

  static hf_register_info hf[] =

  {

    { &hf_pdc_len,

      { "Length Indicator", "pdc.li",

        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_pdc_mpdu_code,

      { "MPDU code", "pdc.mpducode",

        FT_UINT8, BASE_DEC, VALS(valstr_mpdus), 0x0, NULL, HFILL }},

    { &hf_pdc_credit,

      { "Credit", "pdc.cdt",

        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_pdc_yr_admu_nr,

      { "YR-ADMU-NR", "pdc.yradmunr",

        FT_UINT32, BASE_DEC, NULL, 0x0, NULL , HFILL }},

    { &hf_pdc_simpdu_state,

      { "State", "pdc.state",

        FT_UINT8, BASE_DEC, VALS(valstr_simpdu_state), 0x0, NULL, HFILL }},

    { &hf_pdc_akmpdu_mns,

      { "MNS", "pdc.akmpdu.mns",

        FT_UINT16, BASE_DEC, NULL, 0x8000, NULL, HFILL }},

    { &hf_pdc_akmpdu_cdt,

      { "CDT", "pdc.akmpdu.cdt",

        FT_UINT16, BASE_DEC, NULL, 0x07FF, NULL, HFILL }},

    { &hf_pdc_simpdu_var,

      { "Variable Part", "pdc.simpdu.variable",

        FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }},

    { &hf_pdc_simpdu_param,

      { "Parameter", "pdc.simpdu.param",

        FT_UINT8, BASE_DEC, VALS(valstr_simpdu_param), 0x0, NULL, HFILL }},

    { &hf_pdc_simpdu_var_len,

      { "Length", "pdc.simpdu.variable.length",

        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_pdc_simpdu_var_version,

      { "PDC Version Number", "pdc.simpdu.variable.version",

        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_pdc_simpdu_var_REFSRC,

      { "Reference Source", "pdc.simpdu.variable.refsrc",

        FT_UINT32, BASE_DEC, NULL, 0x0,NULL, HFILL }},

    { &hf_pdc_simpdu_var_REFDEST,

      { "Reference Destination", "pdc.simpdu.variable.refdst",

        FT_UINT32, BASE_DEC, NULL, 0x0,NULL, HFILL }},

    { &hf_pdc_simpdu_var_TSEL,

      { "Transport Selector", "pdc.simpdu.tsel",

        FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_pdc_drmpdu_abort,

      { "Abort", "pdc.drmpdu.abort",

        FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_abort), 0x80, NULL, HFILL }},

    { &hf_pdc_drmpdu_reason,

      { "Reason", "pdc.drmpdu.reason",

        FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_reason), 0x0, NULL, HFILL }},

    { &hf_pdc_drmpdu_mode,

      { "Mode", "pdc.drmpdu.mode",

        FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_mode), 0x70, NULL, HFILL }},

    { &hf_pdc_drmpdu_init,

      { "Reason", "pdc.drmpdu.init",

        FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_initatior), 0x0F, NULL, HFILL }},

    { &hf_pdc_dtmpdu_user_size,

      { "User Data Length", "pdc.dtmpdu.usersize",

        FT_UINT16, BASE_DEC, NULL, 0x0, NULL , HFILL }},

    { &hf_pdc_admpdu_admpdunr,

      { "AD-MPDU-NR", "pdc.admpdu.admpdunr",

        FT_UINT32,  BASE_DEC, NULL, 0x0, NULL , HFILL }},

    { &hf_pdc_admpdu_size,

      { "User Data Size", "pdc.admpdu.usersize",

        FT_UINT16, BASE_DEC, NULL, 0x0, NULL , HFILL }},

  };

  /* Setup protocol subtree array */

  static int *ett[] = {

    &ett_pdc,

    &ett_pdc_simpdu_var

  };

  proto_pdc = proto_register_protocol ("PDC Protocol", "PDC", "pdc");

  /*Required Function Calls to register the header fields and subtrees used*/

  proto_register_field_array(proto_pdc, hf, array_length(hf));

  proto_register_subtree_array(ett, array_length(ett));

  /* Register our dissector handle */

  pdc_tcp_handle = register_dissector("pdc", tcp_dissect_pdc, proto_pdc);

}

/* Function to add pdc dissector to tcp.port dissector table and to get handle for asterix dissector */

void proto_reg_handoff_pdc(void)

{

  asterix_handle = find_dissector_add_dependency("asterix", proto_pdc);

  dissector_add_for_decode_as_with_preference("tcp.port", pdc_tcp_handle);

}

/*

 * 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:

 */