/* packet-bofl.c

 * Routines for Wellfleet BOFL dissection

 * Wellfleet -> Baynetworks -> Nortel -> Avaya -> Extremenetworks

 * Protocol is now called Simple Loop Protection Protocol (SLPP)

 * Author: Endoh Akira (endoh@netmarks.co.jp)

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@unicom.net>

 * Copyright 1998 Gerald Combs

 *

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

 *

 * The following information was copied from

 * http://web.archive.org/web/20150608035209/http://www.protocols.com/pbook/bridge.htm#WellfleetBOFL

 *

 * The Wellfleet Breath of Life (BOFL) protocol is used as a line sensing

 * protocol on:

 *

 * - Ethernet LANs to detect transmitter jams.

 * - Synchronous lines running WFLT STD protocols to determine if the line

 *   is up.

 * - Dial backup PPP lines.

 *

 * The frame format of Wellfleet BOFL is shown following the Ethernet header

 * in the following illustration:

 *

 *  Destination   Source    8102    PDU   Sequence   Padding

 *       6           6        2      4       4       n bytes

 */

/* From the above link:

 *

 * Wellfleet BOFL

 *

 * The Wellfleet Breath of Life (BOFL) protocol is used as a line sensing protocol on:

 *

 * Ethernet LANs to detect transmitter jams.

 * Synchronous lines running WFLT STD protocols to determine if the line is up.

 * Dial backup PPP lines.

 * The frame format of Wellfleet BOFL is shown following the Ethernet header in the following illustration:

 *

 * Destination | Source |8102 | PDU | Sequence | Padding

 *  6          |  6     | 2   |  4  |  4       | n bytes

 * <-------------------------->

 *       Ethernet Header

 *

 * 8102

 * EtherType (0x8102 for Wellfleet BOFL frames).

 *

 * PDU

 * PDU field normally equals 0x01010000, but may equal 0x01011111 in some new releases on synchronous links.

 *

 * Sequence

 * 4-byte sequence field is an incremental counter.

 *

 * Padding

 * Padding to fill out the frame to 64 bytes.

 */

#include "config.h"

#include <epan/packet.h>

#define ETHER_TYPE_SLPP 0x8102

#define BOFL_MIN_LEN    8

void proto_register_bofl(void);

void proto_reg_handoff_bofl(void);

static dissector_handle_t bofl_handle;

/* Initialize the protocol and registered fields */

static int proto_bofl;

static int hf_bofl_pdu;

static int hf_bofl_sequence;

static int hf_bofl_padding;

/* Initialize the subtree pointers */

static int ett_bofl;

/* Code to actually dissect the packets */

static int

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

{

    proto_item  *ti;

    proto_tree  *bofl_tree;

    int         len;

    uint32_t    pdu, sequence;

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

    col_clear(pinfo->cinfo, COL_INFO);

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

    bofl_tree = proto_item_add_subtree(ti, ett_bofl);

    pdu = tvb_get_ntohl(tvb, 0);

    col_add_fstr(pinfo->cinfo, COL_INFO,

        "PDU: 0x%08x", pdu);

    proto_tree_add_uint(bofl_tree, hf_bofl_pdu, tvb, 0, 4, pdu);

    sequence = tvb_get_ntohl(tvb, 4);

    col_append_fstr(pinfo->cinfo, COL_INFO,

        " Sequence: %u", sequence);

    proto_tree_add_uint(bofl_tree, hf_bofl_sequence, tvb, 4, 4, sequence);

    len = tvb_reported_length_remaining(tvb, 8);

    if (len > 0)

        proto_tree_add_item(bofl_tree, hf_bofl_padding, tvb, 8, -1, ENC_NA);

    return tvb_captured_length(tvb);

}

void

proto_register_bofl(void)

{

    static hf_register_info hf[] = {

        { &hf_bofl_pdu,

          { "PDU", "bofl.pdu",

            FT_UINT32, BASE_HEX, NULL, 0,

            "PDU; normally equals 0x01010000 or 0x01011111", HFILL }

        },

        { &hf_bofl_sequence,

          { "Sequence", "bofl.sequence",

            FT_UINT32, BASE_DEC, NULL, 0,

            "incremental counter", HFILL }

        },

        { &hf_bofl_padding,

          { "Padding", "bofl.padding",

            FT_BYTES, BASE_NONE, NULL, 0,

            NULL, HFILL }

        }

    };

    static int *ett[] = {

        &ett_bofl,

    };

    proto_bofl = proto_register_protocol("Wellfleet Breath of Life",

                                         "BOFL", "bofl");

    proto_register_field_array(proto_bofl, hf, array_length(hf));

    proto_register_subtree_array(ett, array_length(ett));

    bofl_handle = register_dissector("bofl", dissect_bofl, proto_bofl);

}

void

proto_reg_handoff_bofl(void)

{

    dissector_add_uint("ethertype", ETHER_TYPE_SLPP, bofl_handle);

}

/*

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

 *

 * Local variables:

 * c-basic-offset: 4

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

 * vi: set shiftwidth=4 tabstop=8 expandtab:

 * :indentSize=4:tabSize=8:noTabs=true:

 */