wireshark/epan/dissectors/packet-elmi.c

/* packet-elmi.c
 * Routines for Ethernet Local Management Interface (E-LMI) dissection
 * Copyright 2014, Martin Kaiser <martin@kaiser.cx>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* E-LMI is defined in the MEF16 specification from Metro Ethernet Forum
   http://www.metroethernetforum.org/PDF_Documents/technical-specifications/MEF16.pdf */

#include "config.h"

#include <glib.h>
#include <epan/value_string.h>
#include <epan/etypes.h>
#include <epan/packet.h>


static int proto_elmi = -1;

void proto_register_elmi(void);
void proto_reg_handoff_elmi(void);

static gint ett_elmi = -1;

static int hf_elmi_ver = -1;
static int hf_elmi_msg_type = -1;

static const value_string elmi_msg_type[] = {
    { 0x75, "Status enquiry" },
    { 0x7C, "Status" },
    { 0, NULL }
};


static int
dissect_elmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
    proto_item *pi;
    proto_tree *elmi_tree;
    gint        offset=0;
    guint8      msg_type;

    col_clear(pinfo->cinfo, COL_INFO);
    col_set_str(pinfo->cinfo, COL_PROTOCOL, "E-LMI");

    pi = proto_tree_add_protocol_format(tree, proto_elmi,
            tvb, 0, tvb_captured_length(tvb),
            "Ethernet Local Management Interface (E-LMI)");
    elmi_tree = proto_item_add_subtree(pi, ett_elmi);

    proto_tree_add_item(elmi_tree, hf_elmi_ver, tvb, offset, 1, ENC_BIG_ENDIAN);
    offset++;

    msg_type = tvb_get_guint8(tvb, offset);
    proto_tree_add_item(elmi_tree, hf_elmi_msg_type,
            tvb, offset, 1, ENC_BIG_ENDIAN);
    col_append_fstr(pinfo->cinfo, COL_INFO, "%s",
            val_to_str(msg_type, elmi_msg_type, "unknown (0x%x)"));

    return tvb_captured_length(tvb);
}


void
proto_register_elmi(void)
{
    static hf_register_info hf[] = {
        { &hf_elmi_ver,
            { "Version", "elmi.version", FT_UINT8, BASE_DEC,
                NULL, 0, NULL, HFILL } },
        { &hf_elmi_msg_type,
            { "Message type", "elmi.message_type", FT_UINT8, BASE_HEX,
                VALS(elmi_msg_type), 0, NULL, HFILL } }
    };

    static gint *ett[] = {
        &ett_elmi
    };


    proto_elmi = proto_register_protocol(
            "Ethernet Local Management Interface", "E-LMI", "elmi");

    proto_register_field_array(proto_elmi, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
}


void
proto_reg_handoff_elmi(void)
{
    dissector_handle_t elmi_handle;

    elmi_handle = new_create_dissector_handle(dissect_elmi, proto_elmi);
    dissector_add_uint("ethertype", ETHERTYPE_ELMI, elmi_handle);
}

/*
 * Editor modelines  -  http://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:
 */