![Michael Mann](/assets/img/avatar_default.png)
The main driving force for this was my new Decode As functionality (https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=9450) that wants a dissector/subdissector table relationship for all dissectors wanting to use Decode As functionality. The ethertype() function provides the value to the "ethertype" subdissector table, so I think it should be matched to a dissector. Only odd side effect is the display filter of "ethertype" returns no packets because there is no "item" associated with the dissector. svn path=/trunk/; revision=53443
196 lines
5.8 KiB
C
196 lines
5.8 KiB
C
/* packet-tte.c
|
|
* Routines for Time Triggered Ethernet dissection
|
|
*
|
|
* Author: Valentin Ecker, valentin.ecker (AT) tttech.com
|
|
* Author: Benjamin Roch, benjamin.roch (AT) tttech.com
|
|
*
|
|
* TTTech Computertechnik AG, Austria.
|
|
* http://www.tttech.com/solutions/ttethernet/
|
|
*
|
|
* $Id$
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <glib.h>
|
|
|
|
#include <epan/packet.h>
|
|
#include <epan/prefs.h>
|
|
#include <epan/etypes.h>
|
|
|
|
#include "packet-tte.h"
|
|
|
|
static dissector_handle_t ethertype_handle;
|
|
|
|
/* Initialize the protocol and registered fields */
|
|
static int proto_tte = -1;
|
|
|
|
static int hf_eth_dst = -1;
|
|
static int hf_tte_dst_cf = -1;
|
|
static int hf_tte_ctid = -1;
|
|
static int hf_eth_src = -1;
|
|
static int hf_eth_type = -1;
|
|
|
|
/* preference value pointers */
|
|
static guint32 tte_pref_ct_marker = 0xFFFFFFFF;
|
|
static guint32 tte_pref_ct_mask = 0x0;
|
|
|
|
/* Initialize the subtree pointers */
|
|
static gint ett_tte = -1;
|
|
static gint ett_tte_macdest = -1;
|
|
|
|
|
|
/* Code to actually dissect the packets */
|
|
static int
|
|
dissect_tte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
|
|
{
|
|
int is_frame_pcf;
|
|
ethertype_data_t ethertype_data;
|
|
|
|
/* Set up structures needed to add the protocol subtree and manage it */
|
|
proto_item *tte_root_item, *tte_macdest_item;
|
|
proto_tree *tte_tree, *tte_macdest_tree;
|
|
|
|
/* Check that there's enough data */
|
|
if (tvb_length(tvb) < TTE_HEADER_LENGTH)
|
|
return 0;
|
|
|
|
/* check if data of pcf frame */
|
|
is_frame_pcf =
|
|
(tvb_get_ntohs(tvb, TTE_MAC_LENGTH * 2) == ETHERTYPE_TTE_PCF);
|
|
|
|
/* return if no valid constant field is found */
|
|
if (!is_frame_pcf)
|
|
{
|
|
if ( (tvb_get_ntohl(tvb, 0) & tte_pref_ct_mask) != tte_pref_ct_marker)
|
|
return 0;
|
|
}
|
|
|
|
/* Make entries in Protocol column and Info column on summary display */
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "TTE ");
|
|
|
|
col_set_str(pinfo->cinfo, COL_INFO, "Bogus TTEthernet Frame");
|
|
|
|
if (tree) {
|
|
|
|
/* create display subtree for the protocol */
|
|
tte_root_item = proto_tree_add_item(tree, proto_tte, tvb, 0,
|
|
TTE_HEADER_LENGTH, ENC_NA);
|
|
|
|
tte_tree = proto_item_add_subtree(tte_root_item, ett_tte);
|
|
|
|
tte_macdest_item = proto_tree_add_item(tte_tree,
|
|
hf_eth_dst, tvb, 0, TTE_MAC_LENGTH, ENC_NA);
|
|
|
|
proto_tree_add_item(tte_tree,
|
|
hf_eth_src, tvb, TTE_MAC_LENGTH, TTE_MAC_LENGTH, ENC_NA);
|
|
|
|
proto_tree_add_item(tte_tree,
|
|
hf_eth_type, tvb, TTE_MAC_LENGTH*2, TTE_ETHERTYPE_LENGTH,
|
|
ENC_BIG_ENDIAN);
|
|
|
|
tte_macdest_tree = proto_item_add_subtree(tte_macdest_item,
|
|
ett_tte_macdest);
|
|
|
|
proto_tree_add_item(tte_macdest_tree,
|
|
hf_tte_dst_cf, tvb, 0, TTE_MACDEST_CF_LENGTH, ENC_BIG_ENDIAN);
|
|
|
|
proto_tree_add_item(tte_macdest_tree,
|
|
hf_tte_ctid, tvb, TTE_MACDEST_CF_LENGTH,
|
|
TTE_MACDEST_CTID_LENGTH, ENC_BIG_ENDIAN);
|
|
}
|
|
|
|
/* prevent clearing the Columns...appending cannot be prevented */
|
|
col_set_fence(pinfo->cinfo, COL_PROTOCOL);
|
|
|
|
/* call std Ethernet dissector */
|
|
ethertype_data.etype = tvb_get_ntohs(tvb, TTE_MAC_LENGTH * 2);
|
|
ethertype_data.offset_after_ethertype = 14;
|
|
ethertype_data.fh_tree = NULL;
|
|
ethertype_data.etype_id = hf_eth_type;
|
|
ethertype_data.trailer_id = 0;
|
|
ethertype_data.fcs_len = 0;
|
|
|
|
call_dissector_with_data(ethertype_handle, tvb, pinfo, tree, ðertype_data);
|
|
return tvb_length(tvb);
|
|
}
|
|
|
|
|
|
void
|
|
proto_register_tte(void)
|
|
{
|
|
module_t *tte_module;
|
|
|
|
static hf_register_info hf[] = {
|
|
{ &hf_tte_dst_cf,
|
|
{ "Constant Field", "tte.cf",
|
|
FT_UINT32, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_tte_ctid,
|
|
{ "Critical Traffic Identifier", "tte.ctid",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
}
|
|
};
|
|
|
|
/* Setup protocol subtree array */
|
|
static gint *ett[] = {
|
|
&ett_tte,
|
|
&ett_tte_macdest
|
|
};
|
|
|
|
/* Register the protocol name and description */
|
|
proto_tte = proto_register_protocol("TTEthernet", "TTE", "tte");
|
|
|
|
/* Required function calls to register header fields and subtrees used */
|
|
proto_register_field_array(proto_tte, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
|
|
/* Register preferences module */
|
|
tte_module = prefs_register_protocol(proto_tte, NULL);
|
|
|
|
/* Register preferences */
|
|
prefs_register_uint_preference(tte_module, "ct_mask_value",
|
|
"CT Mask (in hex)",
|
|
"Critical Traffic Mask (base hex)",
|
|
16, &tte_pref_ct_mask);
|
|
|
|
prefs_register_uint_preference(tte_module, "ct_marker_value",
|
|
"CT Marker (in hex)",
|
|
"Critical Traffic Marker (base hex)",
|
|
16, &tte_pref_ct_marker);
|
|
}
|
|
|
|
|
|
void
|
|
proto_reg_handoff_tte(void)
|
|
{
|
|
heur_dissector_add("eth", dissect_tte, proto_tte);
|
|
|
|
hf_eth_dst = proto_registrar_get_id_byname ("eth.dst");
|
|
hf_eth_src = proto_registrar_get_id_byname ("eth.src");
|
|
hf_eth_type = proto_registrar_get_id_byname ("eth.type");
|
|
|
|
ethertype_handle = find_dissector("ethertype");
|
|
}
|