/*

 * Copyright (c) 2003 Markus Friedl.  All rights reserved.

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include "config.h"

#include <epan/packet.h>

#include <epan/ipproto.h>

#include <epan/expert.h>

void proto_register_etherip(void);

void proto_reg_handoff_etherip(void);

static int proto_etherip;

static int hf_etherip_ver;

static int hf_etherip_reserved;

static int ett_etherip;

static expert_field ei_etherip_ver_3;

static expert_field ei_etherip_reserved_0;

static dissector_handle_t eth_withoutfcs_handle;

static dissector_handle_t etherip_handle;

/*

 * RFC 3378: EtherIP: Tunneling Ethernet Frames in IP Datagrams

 *

 *      Bits 0-3:  Protocol version

 *      Bits 4-15: Reserved for future use

 */

#define ETHERIP_VERS_MASK    0xF000

#define ETHERIP_RESERVE_MASK 0x0FFF

static int

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

{

  tvbuff_t *next_tvb;

  proto_tree *etherip_tree;

  proto_item *ti;

  uint16_t field, version;

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

  field = tvb_get_ntohs(tvb, 0);

  version = (field & ETHERIP_VERS_MASK) >> 12;

  if (tree) {

    ti = proto_tree_add_protocol_format(tree, proto_etherip, tvb, 0,

             2,

             "EtherIP, Version %d",

             version

             );

    etherip_tree = proto_item_add_subtree(ti, ett_etherip);

    ti = proto_tree_add_item(etherip_tree, hf_etherip_ver, tvb,

             0, 2, ENC_BIG_ENDIAN);

    if (version != 3) {

      expert_add_info(pinfo, ti, &ei_etherip_ver_3);

    }

    ti = proto_tree_add_item(etherip_tree, hf_etherip_reserved, tvb,

             0, 2, ENC_BIG_ENDIAN);

    if ((field & ETHERIP_RESERVE_MASK) != 0) {

      expert_add_info(pinfo, ti, &ei_etherip_reserved_0);

    }

  }

  /* Set the tvbuff for the payload after the header */

  next_tvb = tvb_new_subset_remaining(tvb, 2);

  call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree);

  return tvb_captured_length(tvb);

}

void

proto_register_etherip(void)

{

  static hf_register_info hf_etherip[] = {

    { &hf_etherip_ver,

      { "Version", "etherip.ver", FT_UINT16, BASE_DEC, NULL, ETHERIP_VERS_MASK,

        NULL, HFILL }},

    { &hf_etherip_reserved,

      { "Reserved", "etherip.reserved", FT_UINT16, BASE_HEX, NULL, ETHERIP_RESERVE_MASK,

        "Reserved (must be 0)", HFILL }},

  };

  static int *ett[] = {

    &ett_etherip,

  };

  static ei_register_info ei[] = {

     { &ei_etherip_ver_3, { "etherip.ver.not3", PI_PROTOCOL, PI_WARN, "Version must be 3", EXPFILL }},

     { &ei_etherip_reserved_0, { "etherip.reserved.not0", PI_PROTOCOL, PI_WARN, "Reserved field must be 0", EXPFILL }},

  };

  expert_module_t* expert_etherip;

  proto_etherip = proto_register_protocol("Ethernet over IP",

                                          "ETHERIP", "etherip");

  proto_register_field_array(proto_etherip, hf_etherip, array_length(hf_etherip));

  proto_register_subtree_array(ett, array_length(ett));

  expert_etherip = expert_register_protocol(proto_etherip);

  expert_register_field_array(expert_etherip, ei, array_length(ei));

  etherip_handle = register_dissector("etherip", dissect_etherip, proto_etherip);

}

void

proto_reg_handoff_etherip(void)

{

  eth_withoutfcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_etherip);

  dissector_add_uint("ip.proto", IP_PROTO_ETHERIP, etherip_handle);

}

/*

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

 *

 * Local Variables:

 * c-basic-offset: 2

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

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

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

 */