/* packet-v5ef.c

 * Routines for V5 envelope function frame disassembly

 * Rolf Fiedler <rolf.fiedler@innoventif.de>

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

/*

 * V5 bitstream over HDLC handling

 *

 * V5 references:

 *

 * ETS 300 324-1

 * ETS 300 347-1

 */

#include "config.h"

#include <epan/packet.h>

#include <wiretap/wtap.h>

void proto_register_v5ef(void);

void proto_reg_handoff_v5ef(void);

static int proto_v5ef;

static int hf_v5ef_direction;

static int hf_v5ef_address;

static int hf_v5ef_eah;

static int hf_v5ef_ea1;

static int hf_v5ef_eal;

static int hf_v5ef_ea2;

static int ett_v5ef;

static int ett_v5ef_address;

static dissector_handle_t v5dl_handle, lapd_phdr_handle, v5ef_handle;

/*

 * Bits in the address field.

 */

#define V5EF_EAH    0xfc00  /* Service Access Point Identifier */

#define V5EF_EAH_SHIFT    10

#define V5EF_EA1    0x0100  /* First Address Extension bit */

#define V5EF_EAL    0x00fe  /* Terminal Endpoint Identifier */

#define V5EF_EAL_SHIFT    1

#define V5EF_EA2    0x0001  /* Second Address Extension bit */

static const value_string v5ef_direction_vals[] = {

  { 0,    "AN->LE"},

  { 1,    "LE->AN"},

  { 0,    NULL }

};

#define MAX_V5EF_PACKET_LEN 1024

static int

dissect_v5ef(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)

{

  struct isdn_phdr *isdn = (struct isdn_phdr *)data;

  proto_tree  *v5ef_tree, *addr_tree;

  proto_item  *v5ef_ti, *addr_ti;

  int    direction;

  int    v5ef_header_len;

  uint16_t     addr, eah, eal, efaddr;

  tvbuff_t  *next_tvb;

  const char  *srcname = "src";

  const char  *dstname = "dst";

  col_set_str(pinfo->cinfo, COL_PROTOCOL, "V5-EF");

  col_clear(pinfo->cinfo, COL_INFO);

  addr    = tvb_get_ntohs(tvb, 0);

  eah   = (addr & V5EF_EAH) >> V5EF_EAH_SHIFT;

  eal   = (addr & V5EF_EAL) >> V5EF_EAL_SHIFT;

  efaddr    = (eah << 7) + eal;

  v5ef_header_len = 2;  /* addr */

  direction = isdn->uton;

  if (direction==0) {

          srcname = "LE";

          dstname = "AN";

   } else if (direction > 0) {

          srcname = "AN";

          dstname = "LE";

  }

  col_set_str(pinfo->cinfo, COL_RES_DL_SRC, srcname);

  col_set_str(pinfo->cinfo, COL_RES_DL_DST, dstname);

  if (tree) {

    proto_item *direction_ti;

    v5ef_ti = proto_tree_add_item(tree, proto_v5ef, tvb, 0, -1,

        ENC_NA);

    v5ef_tree = proto_item_add_subtree(v5ef_ti, ett_v5ef);

    /*

     * Don't show the direction if we don't know it.

     */

    if (direction != P2P_DIR_UNKNOWN) {

      direction_ti = proto_tree_add_uint(v5ef_tree, hf_v5ef_direction,

                                         tvb, 0, 0, direction);

      proto_item_set_generated(direction_ti);

    }

    addr_ti = proto_tree_add_uint(v5ef_tree, hf_v5ef_address, tvb,

        0, 2, addr);

    addr_tree = proto_item_add_subtree(addr_ti, ett_v5ef_address);

    proto_tree_add_uint(addr_tree, hf_v5ef_eah,  tvb, 0, 1, addr);

    proto_tree_add_uint(addr_tree, hf_v5ef_ea1, tvb, 0, 1, addr);

    proto_tree_add_uint(addr_tree, hf_v5ef_eal, tvb, 1, 1, addr);

    proto_tree_add_uint(addr_tree, hf_v5ef_ea2, tvb, 1, 1, addr);

  }

  else {

    v5ef_ti   = NULL;

    v5ef_tree = NULL;

  }

  if (tree)

    proto_item_set_len(v5ef_ti, v5ef_header_len);

  next_tvb = tvb_new_subset_remaining(tvb, v5ef_header_len);

  if (efaddr>8175)

    call_dissector(v5dl_handle,next_tvb, pinfo, tree);

  else

    call_dissector_with_data(lapd_phdr_handle, next_tvb, pinfo, tree, isdn);

  return tvb_captured_length(tvb);

}

void

proto_register_v5ef(void)

{

  static hf_register_info hf[] = {

  { &hf_v5ef_direction,

    { "Direction", "v5ef.direction", FT_UINT8, BASE_DEC, VALS(v5ef_direction_vals), 0x0,

      NULL, HFILL }},

  { &hf_v5ef_address,

    { "Address Field", "v5ef.address", FT_UINT16, BASE_HEX, NULL, 0x0,

    NULL, HFILL }},

  { &hf_v5ef_eah,

    { "EAH", "v5ef.eah", FT_UINT16, BASE_DEC, NULL, V5EF_EAH,

      "Envelope Address High Part", HFILL }},

  { &hf_v5ef_ea1,

    { "EA1", "v5ef.ea1", FT_UINT16, BASE_DEC, NULL, V5EF_EA1,

      "First Address Extension bit", HFILL }},

  { &hf_v5ef_eal,

    { "EAL", "v5ef.eal", FT_UINT16, BASE_DEC, NULL, V5EF_EAL,

      "Envelope Address Low Part", HFILL }},

  { &hf_v5ef_ea2,

    { "EA2", "v5ef.ea2", FT_UINT16, BASE_DEC, NULL, V5EF_EA2,

      "Second Address Extension bit", HFILL }},

  };

  static int *ett[] = {

    &ett_v5ef,

    &ett_v5ef_address,

  };

  proto_v5ef = proto_register_protocol("V5 Envelope Function (v5ef)",

           "v5ef", "v5ef");

  proto_register_field_array (proto_v5ef, hf, array_length(hf));

  proto_register_subtree_array(ett, array_length(ett));

  v5ef_handle = register_dissector("v5ef", dissect_v5ef, proto_v5ef);

}

void

proto_reg_handoff_v5ef(void)

{

  dissector_add_uint("wtap_encap", WTAP_ENCAP_V5_EF, v5ef_handle);

  lapd_phdr_handle = find_dissector_add_dependency("lapd-phdr", proto_v5ef);

  v5dl_handle = find_dissector_add_dependency("v5dl", proto_v5ef);

}

/*

 * 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:

 */