/* packet-msgpack.c

 *

 * Routines for MsgPack dissection

 * References:

 *   https://github.com/msgpack/msgpack/

 *

 * Copyright 2018, Dario Lombardo <lomato@gmail.com>

 *

 * 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 <wsutil/array.h>

#include <epan/packet.h>

#include <epan/expert.h>

#include <epan/to_str.h>

void proto_register_msgpack(void);

void proto_reg_handoff_msgpack(void);

dissector_handle_t msgpack_handle;

static int proto_msgpack;

static int hf_msgpack_string;

static int hf_msgpack_type;

static int hf_msgpack_string_len;

static int hf_msgpack_uint_8;

static int hf_msgpack_uint_16;

static int hf_msgpack_uint_32;

static int hf_msgpack_uint_64;

static int hf_msgpack_int_8;

static int hf_msgpack_int_16;

static int hf_msgpack_int_32;

static int hf_msgpack_int_64;

static int hf_msgpack_bool;

static int hf_msgpack_float;

static int hf_msgpack_ext_fixext;

static int hf_msgpack_ext_type;

static int hf_msgpack_ext_bytes;

static int ett_msgpack;

static int ett_msgpack_string;

static int ett_msgpack_array;

static int ett_msgpack_map;

static int ett_msgpack_map_elem;

static int ett_msgpack_ext;

static expert_field ei_msgpack_unsupported;

static const value_string msgpack_ext_fixtexts[] = {

  { 0xd4, "fixext 1" },

  { 0xd5, "fixext 2" },

  { 0xd6, "fixext 4" },

  { 0xd7, "fixext 8" },

  { 0xd8, "fixext 16" },

  { 0, NULL }

};

static void dissect_msgpack_object(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, void* data, int* offset, char** value);

static void dissect_msgpack_integer(tvbuff_t* tvb, packet_info *pinfo, proto_tree* tree, uint8_t type, void* data, int* offset, char** value)

{

  uint8_t uint8;

  uint16_t uint16;

  uint32_t uint32;

  uint64_t uint64;

  int8_t int8;

  int16_t int16;

  int32_t int32;

  int64_t int64;

  char* label;

  label = (data ? (char*)data : "MsgPack Integer");

  if (type >> 7 == 0) {

    proto_tree_add_uint_format(tree, hf_msgpack_uint_8, tvb, *offset, 1, type, "%s: %u", label, type);

    if (value)

      *value = wmem_strdup_printf(pinfo->pool, "%u", type);

    *offset += 1;

    return;

  }

  if (type >> 5 == 7) {

    proto_tree_add_int_format(tree, hf_msgpack_int_8, tvb, *offset, 1, type, "%s: %u", label, type);

    if (value)

      *value = wmem_strdup_printf(pinfo->pool, "%d", type);

    *offset += 1;

    return;

  }

  switch (type) {

    case 0xcc:

      uint8 = tvb_get_uint8(tvb, *offset + 1);

      proto_tree_add_uint_format(tree, hf_msgpack_uint_8, tvb, *offset, 2, uint8, "%s: %u", label, uint8);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%u", uint8);

      *offset += 2;

      break;

    case 0xcd:

      uint16 = tvb_get_ntohs(tvb, *offset + 1);

      proto_tree_add_uint(tree, hf_msgpack_uint_16, tvb, *offset, 3, uint16);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%u", uint16);

      *offset += 3;

      break;

    case 0xce:

      uint32 = tvb_get_ntohl(tvb, *offset + 1);

      proto_tree_add_uint(tree, hf_msgpack_uint_32, tvb, *offset, 5, uint32);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%u", uint32);

      *offset += 5;

      break;

    case 0xcf:

      uint64 = tvb_get_ntoh64(tvb, *offset + 1);

      proto_tree_add_uint64(tree, hf_msgpack_uint_64, tvb, *offset, 9, uint64);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%" PRIu64, uint64);

      *offset += 9;

      break;

    case 0xd0:

      int8 = tvb_get_int8(tvb, *offset + 1);

      proto_tree_add_int(tree, hf_msgpack_int_8, tvb, *offset, 2, int8);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%d", int8);

      *offset += 2;

      break;

    case 0xd1:

      int16 = tvb_get_ntohs(tvb, *offset + 1);

      proto_tree_add_int(tree, hf_msgpack_int_16, tvb, *offset, 3, int16);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%d", int16);

      *offset += 3;

      break;

    case 0xd2:

      int32 = tvb_get_ntohl(tvb, *offset + 1);

      proto_tree_add_int(tree, hf_msgpack_int_32, tvb, *offset, 5, int32);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%d", int32);

      *offset += 5;

      break;

    case 0xd3:

      int64 = tvb_get_ntoh64(tvb, *offset + 1);

      proto_tree_add_int64(tree, hf_msgpack_int_64, tvb, *offset, 9, int64);

      if (value)

        *value = wmem_strdup_printf(pinfo->pool, "%" PRId64, int64);

      *offset += 9;

      break;

    default:

      DISSECTOR_ASSERT_NOT_REACHED();

  }

}

// NOLINTNEXTLINE(misc-no-recursion)

static void dissect_msgpack_map(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, uint8_t type, void* data, int* offset, char** value)

{

  proto_tree* subtree;

  proto_tree* map_subtree;

  proto_item* ti;

  uint8_t len;

  char* label;

  unsigned i;

  len = type & 0x0F;

  label = wmem_strdup_printf(pinfo->pool, "%s: %u element%s", data ? (char*)data : "MsgPack Map", len, len > 1 ? "s" : "");

  ti = proto_tree_add_string_format(tree, hf_msgpack_string, tvb, *offset, 1 + len, NULL, "%s", label);

  subtree = proto_item_add_subtree(ti, ett_msgpack_map);

  *offset += 1;

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

    map_subtree = proto_tree_add_subtree(subtree, tvb, *offset, 0, ett_msgpack_map_elem, NULL, "");

    dissect_msgpack_object(tvb, pinfo, map_subtree, "Key", offset, value);

    if (value)

      proto_item_append_text(map_subtree, " %s:", *value);

    // We recurse here, but we'll run out of packet before we run out of stack.

    dissect_msgpack_object(tvb, pinfo, map_subtree, "Value", offset, value);

    if (value)

      proto_item_append_text(map_subtree, " %s", *value);

  }

  if (value)

    *value = label;

}

// NOLINTNEXTLINE(misc-no-recursion)

static void dissect_msgpack_array(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, uint8_t type, void* data, int* offset, char** value)

{

  proto_tree* subtree;

  proto_item* ti;

  uint32_t len;

  uint32_t lensize = UINT32_MAX;

  char* label;

  unsigned i;

  if (type >> 4 == 0x9) {

    len = type & 0x0F;

    lensize = 0;

  }

  if (type == 0xdc) {

    len = tvb_get_ntohs(tvb, *offset + 1);

    lensize = 2;

  }

  if (type == 0xdd) {

    len = tvb_get_ntohl(tvb, *offset + 1);

    lensize = 4;

  }

  DISSECTOR_ASSERT(lensize != UINT32_MAX);

  label = wmem_strdup_printf(pinfo->pool, "%s %u element%s", data ? (char*)data : "MsgPack Array", len, len > 1 ? "s" : "");

  ti = proto_tree_add_string_format(tree, hf_msgpack_string, tvb, *offset, 1 + len, NULL, "%s", label);

  subtree = proto_item_add_subtree(ti, ett_msgpack_array);

  *offset += lensize + 1;

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

    // We recurse here, but we'll run out of packet before we run out of stack.

    dissect_msgpack_object(tvb, pinfo, subtree, data, offset, value);

  }

  if (value)

    *value = label;

}

static void dissect_msgpack_string(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, int type, void* data, int* offset, char** value)

{

  uint32_t len = 0;

  uint32_t lensize = 0;

  char* label;

  proto_item* ti;

  proto_tree* subtree;

  char* lvalue;

  if (type >> 5 == 0x5) {

    len = type & 0x1F;

    lensize = 0;

  }

  if (type == 0xd9) {

    len = tvb_get_uint8(tvb, *offset + 1);

    lensize = 1;

  }

  if (type == 0xda) {

    len = tvb_get_ntohs(tvb, *offset + 1);

    lensize = 2;

  }

  if (type == 0xdb) {

    len = tvb_get_ntohl(tvb, *offset + 1);

    lensize = 4;

  }

  lvalue = (char*)tvb_get_string_enc(pinfo->pool, tvb, *offset + 1 + lensize, len, ENC_NA);

  label = (data ? (char*)data : "MsgPack String");

  ti = proto_tree_add_string_format(tree, hf_msgpack_string, tvb, *offset, 1 + lensize + len, lvalue, "%s: %s", label, lvalue);

  subtree = proto_item_add_subtree(ti, ett_msgpack_string);

  if (lensize == 0) {

    proto_tree_add_uint_format(subtree, hf_msgpack_type, tvb, *offset, 1, type, "Type: String");

    proto_tree_add_uint_format(subtree, hf_msgpack_string_len, tvb, *offset, 1, lensize, "Length: 1");

    proto_tree_add_item(subtree, hf_msgpack_string, tvb, *offset + 1 + lensize, len, ENC_ASCII);

  } else {

    proto_tree_add_item(subtree, hf_msgpack_type, tvb, *offset, 1, ENC_NA);

    proto_tree_add_item(subtree, hf_msgpack_string_len, tvb, *offset + 1, lensize, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_msgpack_string, tvb, *offset + 1 + lensize, len, ENC_ASCII);

  }

  *offset += 1 + lensize + len;

  if (value)

    *value = lvalue;

}

static void dissect_msgpack_float(tvbuff_t* tvb, packet_info *pinfo, proto_tree* tree, int type, void* data, int* offset, char** value)

{

  char* label;

  char* lvalue;

  label = (data ? (char*)data : "Float");

  *offset += 1;

  if (type == 0xca) {

    float f = tvb_get_ntohieee_float(tvb, *offset);

    lvalue = wmem_strdup_printf(pinfo->pool, "%f", f);

    proto_tree_add_string_format(tree, hf_msgpack_float, tvb, *offset, 4, lvalue, "%s: %f", label, f);

    if (value)

      *value = lvalue;

    *offset += 4;

  } else {

    double d = tvb_get_ntohieee_double(tvb, *offset);

    lvalue = wmem_strdup_printf(pinfo->pool, "%f", d);

    proto_tree_add_string_format(tree, hf_msgpack_float, tvb, *offset, 8, lvalue, "%s: %f", label, d);

    if (value)

      *value = lvalue;

    *offset += 8;

  }

}

static void dissect_msgpack_ext(tvbuff_t* tvb, proto_tree* tree, int type, void* data, int* offset, char** value)

{

  char* label;

  int bytes;

  const uint8_t* start;

  proto_tree* ext_tree;

  unsigned offset_start = *offset;

  label = (data ? (char*)data : "Ext");

  ext_tree = proto_tree_add_subtree(tree, tvb, *offset, 0, ett_msgpack_ext, NULL, label);

  proto_tree_add_item(ext_tree, hf_msgpack_ext_fixext, tvb, *offset, 1, ENC_NA);

  *offset += 1;

  if (type >= 0xd4 && type <= 0xd8) {

    proto_tree_add_item(ext_tree, hf_msgpack_ext_type, tvb, *offset, 1, ENC_NA);

    *offset += 1;

    bytes = 1 << (type - 0xd4);

    start = (const uint8_t*)tvb_get_ptr(tvb, *offset, bytes);

    proto_tree_add_bytes(ext_tree, hf_msgpack_ext_bytes, tvb, *offset, bytes, start);

    if (value)

      *value = bytes_to_hexstr(*value, start, bytes);

    *offset += bytes;

  }

  proto_item_set_len(ext_tree, *offset - offset_start);

}

// NOLINTNEXTLINE(misc-no-recursion)

static void dissect_msgpack_object(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, void* data, int* offset, char** value)

{

  uint8_t type;

  type = tvb_get_uint8(tvb, *offset);

  // Nil

  if (type == 0xc0) {

    proto_tree_add_string_format(tree, hf_msgpack_string, tvb, *offset, 1, "nil", "nil");

    if (value)

      *value = "nil";

    *offset += 1;

    return;

  }

  // True/False

  if (type == 0xc2 || type == 0xc3) {

    proto_tree_add_boolean(tree, hf_msgpack_bool, tvb, *offset, 1, type - 0xc2);

    if (value)

      *value = (type - 0xc2) ? "True" : "False";

    *offset += 1;

    return;

  }

  // Integer

  if (type >= 0xe0 || type <= 0x7f || (type >= 0xcc && type <= 0xd3)) {

    dissect_msgpack_integer(tvb, pinfo, tree, type, data, offset, value);

    return;

  }

  // Float

  if (type == 0xca || type == 0xcb) {

    dissect_msgpack_float(tvb, pinfo, tree, type, data, offset, value);

    return;

  }

  // String

  if (type >> 5 == 0x5 || type == 0xd9 || type == 0xda || type == 0xdb) {

    dissect_msgpack_string(tvb, pinfo, tree, type, data, offset, value);

    return;

  }

  // Array

  if (type >> 4 == 0x9 || type == 0xdc || type == 0xdd) {

    // We recurse here, but we'll run out of packet before we run out of stack.

    dissect_msgpack_array(tvb, pinfo, tree, type, data, offset, value);

    return;

  }

  // Map

  if (type >> 4 == 0x8) {

    // We recurse here, but we'll run out of packet before we run out of stack.

    dissect_msgpack_map(tvb, pinfo, tree, type, data, offset, value);

    return;

  }

  // Ext

  if ((type >= 0xd4 && type <= 0xd8) || (type >= 0xc7 && type <= 0xc9)) {

    dissect_msgpack_ext(tvb, tree, type, data, offset, value);

    return;

  }

  if (*offset == 0) {

    expert_add_info_format(pinfo, tree, &ei_msgpack_unsupported, "Type 0x%x is unsupported", type);

  }

}

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

{

  int offset = 0;

  dissect_msgpack_object(tvb, pinfo, tree, data, &offset, NULL);

  return offset;

}

void proto_register_msgpack(void)

{

  expert_module_t* expert_msgpack;

  static hf_register_info hf[] = {

    { &hf_msgpack_string,

      { "String", "msgpack.string", FT_STRING, BASE_NONE, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_type,

      { "Type", "msgpack.type", FT_UINT8, BASE_HEX, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_string_len,

      { "Length", "msgpack.string.len", FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_uint_8,

      { "Integer", "msgpack.integer.u8", FT_UINT8, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_uint_16,

      { "Integer", "msgpack.integer.u16", FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_uint_32,

      { "Integer", "msgpack.integer.u32", FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_uint_64,

      { "Integer", "msgpack.integer.u64", FT_UINT64, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_int_8,

      { "Integer", "msgpack.integer.8", FT_INT8, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_int_16,

      { "Integer", "msgpack.integer.16", FT_INT16, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_int_32,

      { "Integer", "msgpack.integer.32", FT_INT32, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_int_64,

      { "Integer", "msgpack.integer.64", FT_INT64, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_bool,

      { "Boolean", "msgpack.boolean", FT_BOOLEAN, BASE_NONE, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_float,

      { "Float", "msgpack.float", FT_STRING, BASE_NONE, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_ext_fixext,

      { "Ext fix text", "msgpack.ext.fixtext", FT_UINT8, BASE_HEX, VALS(msgpack_ext_fixtexts), 0x00, NULL, HFILL }

    },

    { &hf_msgpack_ext_type,

      { "Ext type", "msgpack.ext.type", FT_INT8, BASE_DEC, NULL, 0x00, NULL, HFILL }

    },

    { &hf_msgpack_ext_bytes,

      { "Ext", "msgpack.ext", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }

    }

  };

  static int* ett[] = {

    &ett_msgpack,

    &ett_msgpack_string,

    &ett_msgpack_array,

    &ett_msgpack_map,

    &ett_msgpack_map_elem,

    &ett_msgpack_ext

  };

  static ei_register_info ei[] = {

    { &ei_msgpack_unsupported, { "msgpack.unsupported", PI_UNDECODED, PI_WARN, "Unsupported type", EXPFILL }}

  };

  proto_msgpack = proto_register_protocol("Message Pack", "MsgPack", "msgpack");

  msgpack_handle = register_dissector("msgpack", dissect_msgpack, proto_msgpack);

  expert_msgpack = expert_register_protocol(proto_msgpack);

  expert_register_field_array(expert_msgpack, ei, array_length(ei));

  proto_register_field_array(proto_msgpack, hf, array_length(hf));

  proto_register_subtree_array(ett, array_length(ett));

}

void proto_reg_handoff_msgpack(void)

{

  // If this is ever streamed (transported over TCP) we need to add recursion checks

  dissector_add_for_decode_as("udp.port", msgpack_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:

 */