/* packet-ieee802a.c

 * Routines for IEEE 802a

 *

 * 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/addr_resolv.h>

#include <epan/etypes.h>

#include "packet-ieee802a.h"

void proto_register_ieee802a(void);

void proto_reg_handoff_ieee802a(void);

static dissector_handle_t ieee802a_handle;

static int proto_ieee802a;

static int hf_ieee802a_oui;

static int hf_ieee802a_pid;

static int ett_ieee802a;

/*

 * Hash table for translating OUIs to a dissector table/field info pair;

 * the dissector table maps PID values to dissectors, and the field

 * corresponds to the PID for that OUI.

 */

typedef struct {

  dissector_table_t table;

  hf_register_info *field_info;

} oui_info_t;

static GHashTable *oui_info_table;

/*

 * Add an entry for a new OUI.

 */

void

ieee802a_add_oui(uint32_t oui, const char *table_name, const char *table_ui_name,

     hf_register_info *hf_item, const int proto)

{

  oui_info_t *new_info;

  new_info = g_new(oui_info_t, 1);

  new_info->table = register_dissector_table(table_name,

      table_ui_name, proto, FT_UINT16, BASE_HEX);

  new_info->field_info = hf_item;

  /*

   * Create the hash table for OUI information, if it doesn't

   * already exist.

   */

  if (oui_info_table == NULL) {

    oui_info_table = g_hash_table_new_full(g_direct_hash,

        g_direct_equal, NULL, g_free);

  }

  g_hash_table_insert(oui_info_table, GUINT_TO_POINTER(oui), new_info);

}

static int

dissect_ieee802a(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)

{

  proto_tree  *ieee802a_tree;

  proto_item  *ti;

  tvbuff_t  *next_tvb;

  const char  *manuf;

  uint32_t    oui32;

  uint16_t    pid;

  oui_info_t  *oui_info;

  dissector_table_t subdissector_table;

  int   hf;

  col_set_str(pinfo->cinfo, COL_PROTOCOL, "IEEE802a");

  col_clear(pinfo->cinfo, COL_INFO);

  ti = proto_tree_add_item(tree, proto_ieee802a, tvb, 0, 5, ENC_NA);

  ieee802a_tree = proto_item_add_subtree(ti, ett_ieee802a);

  proto_tree_add_item_ret_uint(ieee802a_tree, hf_ieee802a_oui, tvb, 0, 3, ENC_BIG_ENDIAN, &oui32);

  manuf = uint_get_manuf_name_if_known(oui32);

  pid = tvb_get_ntohs(tvb, 3);

  col_add_fstr(pinfo->cinfo, COL_INFO, "OUI %s (%s), PID 0x%04X",

    tvb_bytes_to_str_punct(pinfo->pool, tvb, 0, 3, ':'),

    manuf ? manuf : "Unknown", pid);

  /*

   * Do we have information for this OUI?

   */

  if (oui_info_table != NULL &&

      (oui_info = (oui_info_t *)g_hash_table_lookup(oui_info_table,

        GUINT_TO_POINTER(oui32))) != NULL) {

    /*

     * Yes - use it.

     */

    hf = *oui_info->field_info->p_id;

    subdissector_table = oui_info->table;

  } else {

    /*

     * No, use hf_ieee802a_pid for the PID and just dissect

     * the payload as data.

     */

    hf = hf_ieee802a_pid;

    subdissector_table = NULL;

  }

  proto_tree_add_uint(ieee802a_tree, hf, tvb, 3, 2, pid);

  next_tvb = tvb_new_subset_remaining(tvb, 5);

  if ((subdissector_table == NULL) ||

    /* do lookup with the subdissector table */

    (!dissector_try_uint(subdissector_table, pid, next_tvb, pinfo, tree))) {

      call_data_dissector(next_tvb, pinfo, tree);

  }

  return tvb_captured_length(tvb);

}

static void

ieee802a_shutdown(void)

{

  g_hash_table_destroy(oui_info_table);

}

void

proto_register_ieee802a(void)

{

  static hf_register_info hf[] = {

    { &hf_ieee802a_oui,

      { "Organization Code",  "ieee802a.oui", FT_UINT24, BASE_OUI,

        NULL, 0x0, NULL, HFILL }},

    { &hf_ieee802a_pid,

      { "Protocol ID", "ieee802a.pid", FT_UINT16, BASE_HEX,

        NULL, 0x0, NULL, HFILL }}

  };

  static int *ett[] = {

    &ett_ieee802a,

  };

  proto_ieee802a = proto_register_protocol("IEEE802a OUI Extended Ethertype", "IEEE802a", "ieee802a");

  proto_register_field_array(proto_ieee802a, hf, array_length(hf));

  proto_register_subtree_array(ett, array_length(ett));

  register_shutdown_routine(ieee802a_shutdown);

  ieee802a_handle = register_dissector("ieee802a", dissect_ieee802a, proto_ieee802a);

}

static void

register_hf(void *key _U_, void *value, void *user_data _U_)

{

  oui_info_t *info = (oui_info_t *)value;

  proto_register_field_array(proto_ieee802a, info->field_info, 1);

}

void

proto_reg_handoff_ieee802a(void)

{

  dissector_add_uint("ethertype", ETHERTYPE_IEEE802_OUI_EXTENDED,

      ieee802a_handle);

  /*

   * Register all the fields for PIDs for various OUIs.

   */

  if (oui_info_table != NULL)

    g_hash_table_foreach(oui_info_table, register_hf, NULL);

}

/*

 * 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:

 */