path: root/epan/dissectors/packet-prp.c

/* packet-prp.c
 * Routines for PRP (Parallel Redundancy Protocol; IEC62439 Part 3) dissection
 * Copyright 2007, Sven Meier <msv[AT]zhwin.ch>
 *
 * $Id$
 *
 * Revisions:
 * -
 *
 * A plugin for:
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald[AT]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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdlib.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/etypes.h>
#include <epan/prefs.h>

/**********************************************************/
/* Offsets of fields within a PRP packet.          */
/**********************************************************/
#define    PRP_VERSION_OFFSET                      0
#define    PRP_TYPE_OFFSET                         2
#define    PRP_LENGTH_OFFSET                       3
#define    PRP_SOURCEMACADDRESSA_OFFSET            4
#define    PRP_SOURCEMACADDRESSB_OFFSET            10
#define    PRP_TYPE2_OFFSET                        16
#define    PRP_LENGTH2_OFFSET                      17
#define    PRP_REDBOXVDANMACADDRESS_OFFSET         18

/**********************************************************/
/* Lengths of fields within a PRP packet.          */
/**********************************************************/
#define    PRP_VERSION_LENGTH                      2
#define    PRP_TYPE_LENGTH                         1
#define    PRP_LENGTH_LENGTH                       1
#define    PRP_SOURCE_LENGTH                       6
#define    PRP_TOTAL_LENGTH                        24

/**********************************************************/
/* Channel values for the PRP_TYPE field          */
/**********************************************************/
#define    PRP_TYPE_DUPLICATE_ACCEPT               21
#define    PRP_TYPE_DUPLICATE_DISCARD              20
#define    PRP_TYPE_REDBOX                         30
#define    PRP_TYPE_VDAN                           31

static const value_string prp_type_vals[] = {
  {PRP_TYPE_DUPLICATE_ACCEPT,     "Duplicate Accept"},
  {PRP_TYPE_DUPLICATE_DISCARD,    "Duplicate Discard"},
  {PRP_TYPE_REDBOX,               "Redundancy Box"},
  {PRP_TYPE_VDAN,                 "Virtual Dual Attached Node"},
  {0,                NULL          } };


#define    PRP_LAN_A                               10
#define    PRP_LAN_B                               11

static const value_string prp_lan_vals[] = {
  {PRP_LAN_A,    "LAN A"},
  {PRP_LAN_B,    "LAN B"},
  {0,        NULL } };

/**********************************************************/
/* Initialize the protocol and registered fields      */
/**********************************************************/

void proto_reg_handoff_prp(void);
static int proto_prp = -1;
static module_t *prp_module;

/* Initialize supervision frame fields */
static int hf_prp_supervision_frame_version = -1;
static int hf_prp_supervision_frame_type = -1;
static int hf_prp_supervision_frame_length = -1;
static int hf_prp_supervision_frame_source_mac_address_A = -1;
static int hf_prp_supervision_frame_source_mac_address_B = -1;
static int hf_prp_supervision_frame_type2 = -1;
static int hf_prp_supervision_frame_length2 = -1;
static int hf_prp_supervision_frame_red_box_mac_address = -1;
static int hf_prp_supervision_frame_vdan_mac_address = -1;

/* Initialize trailer fields */
static int hf_prp_redundancy_control_trailer_sequence_nr = -1;
static int hf_prp_redundancy_control_trailer_lan = -1;
static int hf_prp_redundancy_control_trailer_size = -1;


/* Initialize the subtree pointers */
static gint ett_prp_supervision_frame = -1;
static gint ett_prp_redundancy_control_trailer = -1;


/*  Post dissectors (such as the trailer dissector for this protocol)
 *  get called for every single frame anyone loads into Wireshark.
 *  Since this protocol is not of general interest we disable this
 *  protocol by default.
 *
 *  This is done separately from the disabled protocols list mainly so
 *  we can disable it by default.  XXX Maybe there's a better way.
 */
static gboolean prp_enable_dissector = FALSE;


/* Code to actually dissect the packets */
static void
dissect_prp_supervision_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    proto_item *ti;
    proto_tree *prp_tree;
    guint16 tlv2;

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

    col_set_str(pinfo->cinfo, COL_INFO, "Supervision Frame");

    if (!tree)
        return;

    /* create display subtree for the protocol */
    ti = proto_tree_add_item(tree, proto_prp, tvb, 0, PRP_TOTAL_LENGTH,
                 FALSE);

    prp_tree = proto_item_add_subtree(ti, ett_prp_supervision_frame);

    proto_tree_add_item(prp_tree, hf_prp_supervision_frame_version,
                        tvb, PRP_VERSION_OFFSET, PRP_VERSION_LENGTH, ENC_BIG_ENDIAN);

    proto_tree_add_item(prp_tree, hf_prp_supervision_frame_type,
                        tvb, PRP_TYPE_OFFSET, PRP_TYPE_LENGTH, ENC_BIG_ENDIAN);

    proto_tree_add_item(prp_tree, hf_prp_supervision_frame_length,
                        tvb, PRP_LENGTH_OFFSET, PRP_LENGTH_LENGTH, ENC_BIG_ENDIAN);

    proto_tree_add_item(prp_tree, hf_prp_supervision_frame_source_mac_address_A,
                        tvb, PRP_SOURCEMACADDRESSA_OFFSET, PRP_SOURCE_LENGTH,
                       FALSE);

    proto_tree_add_item(prp_tree, hf_prp_supervision_frame_source_mac_address_B,
                        tvb, PRP_SOURCEMACADDRESSB_OFFSET, PRP_SOURCE_LENGTH,
                        FALSE);


    tlv2 = tvb_get_ntohs(tvb, PRP_TYPE2_OFFSET);

    if((tlv2 == 0x1e06) || (tlv2 == 0x1f06))
    {
        proto_tree_add_item(prp_tree, hf_prp_supervision_frame_type2,
                            tvb, PRP_TYPE2_OFFSET, PRP_TYPE_LENGTH, ENC_BIG_ENDIAN);

        proto_tree_add_item(prp_tree, hf_prp_supervision_frame_length2,
                            tvb, PRP_LENGTH2_OFFSET, PRP_LENGTH_LENGTH, ENC_BIG_ENDIAN);

        if(tlv2 == 0x1e06)
        {
            proto_tree_add_item(prp_tree, hf_prp_supervision_frame_red_box_mac_address,
                                tvb, PRP_REDBOXVDANMACADDRESS_OFFSET, PRP_SOURCE_LENGTH,
                                FALSE);
        }
        else
        {
            proto_tree_add_item(prp_tree, hf_prp_supervision_frame_vdan_mac_address,
                                tvb, PRP_REDBOXVDANMACADDRESS_OFFSET, PRP_SOURCE_LENGTH,
                                FALSE);
        }

     }
}

static void
dissect_prp_redundancy_control_trailer(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
    proto_item *ti;
    proto_tree *prp_tree;
    guint i;
    guint length;
    guint offset;
    guint16 lan_size;
    guint trailer_offset;

    if (!tree)
        return;

    trailer_offset = 0;
    length = tvb_reported_length(tvb);

    if(length < 14)
    {
        return;
    }

    if(ETHERTYPE_VLAN == tvb_get_ntohs(tvb, 12)) /* tagged frame */
    {
        offset = 18;
    }
    else /* untagged */
    {
        offset = 14;
    }

    if(length <= 64)
    {
        for(i=length; i>=(offset+4); i--)  /* search trailer */
        {
            lan_size = tvb_get_ntohs(tvb, (i-2));
            if((lan_size == (0xa000 | ((i-offset) & 0x0fff)))
               || (lan_size == (0xb000 | ((i-offset) & 0x0fff))))
            {
                trailer_offset = i;
            }
        }
    }
    else if(length > 64)
    {
        lan_size = tvb_get_ntohs(tvb, (length-2));
        if((lan_size == (0xa000 | ((length-offset) & 0x0fff)))
            || (lan_size == (0xb000 | ((length-offset) & 0x0fff))))
        {
            trailer_offset = length;
        }
    }

    if(trailer_offset != 0)
    {
        /* create display subtree for the protocol */
        ti = proto_tree_add_item(tree, proto_prp, tvb, trailer_offset - 4,
                     trailer_offset, FALSE);

        prp_tree = proto_item_add_subtree(ti, ett_prp_redundancy_control_trailer);

        proto_tree_add_item(prp_tree, hf_prp_redundancy_control_trailer_sequence_nr,
                            tvb, (trailer_offset-4), 2, ENC_BIG_ENDIAN);

        proto_tree_add_item(prp_tree, hf_prp_redundancy_control_trailer_lan,
                            tvb, (trailer_offset-2), 2, ENC_BIG_ENDIAN);

        proto_tree_add_item(prp_tree, hf_prp_redundancy_control_trailer_size,
                            tvb, (trailer_offset-2), 2, ENC_BIG_ENDIAN);
    }
}

/* Register the protocol with Wireshark */
void proto_register_prp(void)
{
    static hf_register_info hf[] = {

        /*supervision frame*/
        { &hf_prp_supervision_frame_version,
            { "version", "prp.supervision_frame.version",
            FT_UINT16, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_prp_supervision_frame_type,
            { "type", "prp.supervision_frame.type",
            FT_UINT8, BASE_DEC, VALS(prp_type_vals), 0x00,
            NULL, HFILL }
        },
        { &hf_prp_supervision_frame_length,
            { "length", "prp.supervision_frame.length",
            FT_UINT8, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_prp_supervision_frame_source_mac_address_A,
            { "sourceMacAddressA", "prp.supervision_frame.prp_source_mac_address_A",
            FT_ETHER, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_prp_supervision_frame_source_mac_address_B,
            { "sourceMacAddressB", "prp.supervision_frame.prp_source_mac_address_B",
            FT_ETHER, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
	{ &hf_prp_supervision_frame_type2,
            { "type2", "prp.supervision_frame.type2",
            FT_UINT8, BASE_DEC, VALS(prp_type_vals), 0x00,
            NULL, HFILL }
        },
        { &hf_prp_supervision_frame_length2,
            { "length2", "prp.supervision_frame.length2",
            FT_UINT8, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_prp_supervision_frame_red_box_mac_address,
            { "redBoxMacAddress", "prp.supervision_frame.prp_red_box_mac_address",
            FT_ETHER, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_prp_supervision_frame_vdan_mac_address,
            { "vdanMacAddress", "prp.supervision_frame.prp_vdan_mac_address",
            FT_ETHER, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },

        /*trailer*/
        { &hf_prp_redundancy_control_trailer_sequence_nr,
            { "sequenceNr", "prp.trailer.prp_sequence_nr",
            FT_UINT16, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },

        { &hf_prp_redundancy_control_trailer_lan,
            { "lan", "prp.trailer.prp_lan",
            FT_UINT16, BASE_DEC, VALS(prp_lan_vals), 0xf000,
            NULL, HFILL }
        },

        { &hf_prp_redundancy_control_trailer_size,
            { "size", "prp.trailer.prp_size",
            FT_UINT16, BASE_DEC, NULL, 0x0fff,
            NULL, HFILL }
        }
    };

    static gint *ett[] = {
        &ett_prp_supervision_frame,
        &ett_prp_redundancy_control_trailer,
    };


    /* Register the protocol name and description */
    proto_prp = proto_register_protocol("Parallel Redundancy Protocol (IEC62439 Part 3)",
                        "PRP", "prp");
    prp_module = prefs_register_protocol(proto_prp, proto_reg_handoff_prp);

    prefs_register_bool_preference(prp_module, "enable", "Enable dissector",
                       "Enable this dissector (default is false)",
                       &prp_enable_dissector);

    /* Required function calls to register the header fields and subtree used */
    proto_register_field_array(proto_prp, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));

}

void proto_reg_handoff_prp(void)
{
    static gboolean prefs_initialized = FALSE;

    if (!prefs_initialized) {
        dissector_handle_t prp_supervision_frame_handle;
        dissector_handle_t prp_redundancy_control_trailer_handle;

        prp_supervision_frame_handle = create_dissector_handle(dissect_prp_supervision_frame, proto_prp);
        dissector_add_uint("ethertype", ETHERTYPE_PRP, prp_supervision_frame_handle);

        prp_redundancy_control_trailer_handle = create_dissector_handle(dissect_prp_redundancy_control_trailer, proto_prp);
        register_postdissector(prp_redundancy_control_trailer_handle);

        prefs_initialized = TRUE;
    }

      proto_set_decoding(proto_prp, prp_enable_dissector);
}