/* packet-ziop.c

 * Routines for CORBA ZIOP packet disassembly

 * Significantly based on packet-giop.c

 * Copyright 2009 Alvaro Vega Garcia <avega at tid dot es>

 *

 * According with GIOP Compression RFP revised submission

 * OMG mars/2008-12-20

 * https://www.omg.org/spec/ZIOP/1.0/Beta1/PDF

 *

 * 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 <epan/expert.h>

#include "packet-ziop.h"

#include "packet-giop.h"

#include "packet-tcp.h"

/*

 * Set to 1 for DEBUG output - TODO make this a runtime option

 */

#define DEBUG   0

void proto_reg_handoff_ziop(void);

void proto_register_ziop(void);

/*

 * ------------------------------------------------------------------------------------------+

 *                                 Data/Variables/Structs

 * ------------------------------------------------------------------------------------------+

 */

static int proto_ziop;

/*

 * (sub)Tree declares

 */

static int hf_ziop_magic;

static int hf_ziop_giop_version_major;

static int hf_ziop_giop_version_minor;

static int hf_ziop_flags;

static int hf_ziop_message_type;

static int hf_ziop_message_size;

static int hf_ziop_compressor_id;

static int hf_ziop_original_length;

static int ett_ziop;

static expert_field ei_ziop_version;

static dissector_handle_t ziop_tcp_handle;

static const value_string ziop_compressor_ids[] = {

  { 0, "None" },

  { 1, "GZIP"},

  { 2, "PKZIP"},

  { 3, "BZIP2"},

  { 4, "ZLIB"},

  { 5, "LZMA"},

  { 6, "LZOP"},

  { 7, "RZIP"},

  { 8, "7X"},

  { 9, "XAR"},

  { 0, NULL}

};

static const value_string giop_message_types[] = {

  { 0x0, "Request" },

  { 0x1, "Reply"},

  { 0x2, "CancelRequest"},

  { 0x3, "LocateRequest"},

  { 0x4, "LocateReply"},

  { 0x5, "CloseConnection"},

  { 0x6, "MessageError"},

  { 0x7, "Fragment"},

  { 0, NULL}

};

static bool ziop_desegment = true;

/* Main entry point */

static int

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

  unsigned offset = 0;

  uint8_t giop_version_major, giop_version_minor, message_type;

  proto_tree *ziop_tree = NULL;

  proto_item *ti;

  uint8_t flags;

  unsigned byte_order;

  const char *label = "none";

  if (tvb_reported_length(tvb) < 7)

      return 0;

  col_set_str (pinfo->cinfo, COL_PROTOCOL, ZIOP_MAGIC);

  /* Clear out stuff in the info column */

  col_clear(pinfo->cinfo, COL_INFO);

  ti = proto_tree_add_item (tree, proto_ziop, tvb, 0, -1, ENC_NA);

  ziop_tree = proto_item_add_subtree (ti, ett_ziop);

  proto_tree_add_item(ziop_tree, hf_ziop_magic, tvb, offset, 4, ENC_ASCII);

  offset += 4;

  proto_tree_add_item(ziop_tree, hf_ziop_giop_version_major, tvb, offset, 1, ENC_BIG_ENDIAN);

  giop_version_major = tvb_get_uint8(tvb, offset);

  offset++;

  proto_tree_add_item(ziop_tree, hf_ziop_giop_version_minor, tvb, offset, 1, ENC_BIG_ENDIAN);

  giop_version_minor = tvb_get_uint8(tvb, offset);

  offset++;

  if ( (giop_version_major < 1) ||

       (giop_version_minor < 2) )  /* earlier than GIOP 1.2 */

  {

      col_add_fstr (pinfo->cinfo, COL_INFO, "Version %u.%u",

                    giop_version_major, giop_version_minor);

      expert_add_info_format(pinfo, ti, &ei_ziop_version,

                               "Version %u.%u not supported",

                               giop_version_major,

                               giop_version_minor);

      call_data_dissector(tvb, pinfo, tree);

      return tvb_reported_length(tvb);

  }

  flags = tvb_get_uint8(tvb, offset);

  byte_order = (flags & 0x01) ? ENC_LITTLE_ENDIAN : ENC_BIG_ENDIAN;

  if (flags & 0x01) {

    label = "little-endian";

  }

  proto_tree_add_uint_format_value(ziop_tree, hf_ziop_flags, tvb, offset, 1,

                                        flags, "0x%02x (%s)", flags, label);

  offset++;

  proto_tree_add_item(ziop_tree, hf_ziop_message_type, tvb, offset, 1, ENC_BIG_ENDIAN);

  message_type = tvb_get_uint8(tvb, offset);

  offset++;

  col_add_fstr (pinfo->cinfo, COL_INFO, "ZIOP %u.%u %s",

                giop_version_major,

                giop_version_minor,

                val_to_str(message_type, giop_message_types,

                           "Unknown message type (0x%02x)")

                );

  proto_tree_add_item(ziop_tree, hf_ziop_message_size, tvb, offset, 4, byte_order);

  offset += 4;

  proto_tree_add_item(ziop_tree, hf_ziop_compressor_id, tvb, offset, 2, byte_order);

  offset += 4;

  proto_tree_add_item(ziop_tree, hf_ziop_original_length, tvb, offset, 4, byte_order);

  return tvb_reported_length(tvb);

}

static unsigned

get_ziop_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)

{

  uint8_t flags;

  unsigned message_size;

  bool stream_is_big_endian;

  if ( tvb_memeql(tvb, 0, (const uint8_t *)ZIOP_MAGIC, 4) != 0)

    return 0;

  flags = tvb_get_uint8(tvb, offset + 6);

  stream_is_big_endian =  ((flags & 0x1) == 0);

  if (stream_is_big_endian)

    message_size = tvb_get_ntohl(tvb, offset + 8);

  else

    message_size = tvb_get_letohl(tvb, offset + 8);

  return message_size + ZIOP_HEADER_SIZE;

}

static int

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

{

  if ( tvb_memeql(tvb, 0, (const uint8_t *)ZIOP_MAGIC, 4) != 0)

    {

      if (tvb_get_ntohl(tvb, 0) == GIOP_MAGIC_NUMBER)

        {

          dissect_giop(tvb, pinfo, tree);

          return tvb_captured_length(tvb);

        }

      return 0;

    }

  tcp_dissect_pdus(tvb, pinfo, tree, ziop_desegment, ZIOP_HEADER_SIZE,

                   get_ziop_pdu_len, dissect_ziop, data);

  return tvb_captured_length(tvb);

}

bool

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

{

  unsigned tot_len;

  conversation_t *conversation;

  /* check magic number and version */

  tot_len = tvb_captured_length(tvb);

  if (tot_len < ZIOP_HEADER_SIZE) /* tot_len < 12 */

    {

      /* Not enough data captured to hold the ZIOP header; don't try

         to interpret it as GIOP. */

      return false;

    }

  if ( tvb_memeql(tvb, 0, (const uint8_t *)ZIOP_MAGIC, 4) != 0)

    {

      return false;

    }

  if ( pinfo->ptype == PT_TCP )

    {

      /*

       * Make the ZIOP dissector the dissector for this conversation.

       *

       * If this isn't the first time this packet has been processed,

       * we've already done this work, so we don't need to do it

       * again.

       */

      if (!pinfo->fd->visited)

        {

          conversation = find_or_create_conversation(pinfo);

          /* Set dissector */

          conversation_set_dissector(conversation, ziop_tcp_handle);

        }

      dissect_ziop_tcp (tvb, pinfo, tree, data);

    }

  else

    {

      dissect_ziop (tvb, pinfo, tree, data);

    }

  return true;

}

void

proto_register_ziop (void)

{

  /* A header field is something you can search/filter on.

   *

   * We create a structure to register our fields. It consists of an

   * array of hf_register_info structures, each of which are of the format

   * {&(field id), {name, abbrev, type, display, strings, bitmask, blurb, HFILL}}.

   */

  static hf_register_info hf[] = {

    { &hf_ziop_magic,

      { "Header magic", "ziop.magic", FT_STRING, BASE_NONE, NULL, 0x0,

        "ZIOPHeader magic", HFILL }},

    { &hf_ziop_giop_version_major,

      { "Header major version", "ziop.giop_version_major", FT_UINT8, BASE_OCT, NULL, 0x0,

        "ZIOPHeader giop_major_version", HFILL }},

    { &hf_ziop_giop_version_minor,

      { "Header minor version", "ziop.giop_version_minor", FT_UINT8, BASE_OCT, NULL, 0x0,

        "ZIOPHeader giop_minor_version", HFILL }},

    { &hf_ziop_flags,

      { "Header flags", "ziop.flags", FT_UINT8, BASE_OCT, NULL, 0x0,

        "ZIOPHeader flags", HFILL }},

    { &hf_ziop_message_type,

      { "Header type", "ziop.message_type", FT_UINT8, BASE_OCT, VALS(giop_message_types), 0x0,

        "ZIOPHeader message_type", HFILL }},

    { &hf_ziop_message_size,

      { "Header size", "ziop.message_size",  FT_UINT32, BASE_DEC, NULL, 0x0,

        "ZIOPHeader message_size", HFILL }},

    { &hf_ziop_compressor_id,

      { "Header compressor id", "ziop.compressor_id", FT_UINT16, BASE_DEC, VALS(ziop_compressor_ids), 0x0,

        "ZIOPHeader compressor_id", HFILL }},

    { &hf_ziop_original_length,

      { "Header original length", "ziop.original_length", FT_UINT32, BASE_DEC, NULL, 0x0,

        "ZIOP original_length", HFILL }}

  };

  static int *ett[] = {

    &ett_ziop

  };

  static ei_register_info ei[] = {

    { &ei_ziop_version, { "ziop.version_not_supported", PI_PROTOCOL, PI_WARN, "Version not supported", EXPFILL }},

  };

  expert_module_t* expert_ziop;

  proto_ziop = proto_register_protocol("Zipped Inter-ORB Protocol", "ZIOP", "ziop");

  proto_register_field_array (proto_ziop, hf, array_length (hf));

  proto_register_subtree_array (ett, array_length (ett));

  expert_ziop = expert_register_protocol(proto_ziop);

  expert_register_field_array(expert_ziop, ei, array_length(ei));

  register_dissector("ziop", dissect_ziop, proto_ziop);

  ziop_tcp_handle = register_dissector("ziop.tcp", dissect_ziop_tcp, proto_ziop);

}

void

proto_reg_handoff_ziop (void)

{

  dissector_add_for_decode_as_with_preference("udp.port", ziop_tcp_handle);

  heur_dissector_add("tcp", dissect_ziop_heur, "ZIOP over TCP", "ziop_tcp", proto_ziop, HEURISTIC_ENABLE);

}

/*

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

 *

 * Local variables:

 * c-basic-offset: 2

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

 * vi: set shiftwidth=2 tabstop=8 expandtab:

 * :indentSize=2:tabSize=8:noTabs=true:

 */