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wireshark/epan/dissectors/packet-macsec.c
Michael Mann 1e60d63c8c Create call_data_dissector() to call data dissector. 
This saves many dissectors the need to find the data dissector and store a handle to it.

There were also some that were finding it, but not using it.
For others this was the only reason for their handoff function, so it could be eliminated.

Change-Id: I5d3f951ee1daa3d30c060d21bd12bbc881a8027b
Reviewed-on: https://code.wireshark.org/review/14530
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-03-20 17:38:03 +00:00

210 lines
8.1 KiB
C
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/* packet-macsec.c
* Routines for MACSEC dissection
* Copyright 2013, Allan W. Nielsen <anielsen@vitesse.com>
*
* 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 <epan/packet.h>
#include <epan/etypes.h>
void proto_register_macsec(void);
void proto_reg_handoff_macsec(void);
#define TCI_V_MASK 0x80
#define TCI_ES_MASK 0x40
#define TCI_SC_MASK 0x20
#define TCI_SCB_MASK 0x10
#define TCI_E_MASK 0x08
#define TCI_C_MASK 0x04
#define TCI_AN_MASK 0x03
static int proto_macsec = -1;
static int hf_macsec_TCI = -1;
static int hf_macsec_TCI_V = -1;
static int hf_macsec_TCI_ES = -1;
static int hf_macsec_TCI_SC = -1;
static int hf_macsec_TCI_SCB = -1;
static int hf_macsec_TCI_E = -1;
static int hf_macsec_TCI_C = -1;
static int hf_macsec_AN = -1;
static int hf_macsec_SL = -1;
static int hf_macsec_PN = -1;
static int hf_macsec_SCI_System_identifier = -1;
static int hf_macsec_SCI_port_number = -1;
static int hf_macsec_ICV = -1;
/* Initialize the subtree pointers */
static gint ett_macsec = -1;
static gint ett_macsec_tci = -1;
/* Code to actually dissect the packets */
static int dissect_macsec(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
unsigned sectag_length, data_length, icv_length = 16;
unsigned sectag_offset = 0, data_offset, icv_offset;
guint8 tci_an_field;
proto_item *macsec_item, *tci_item;
proto_tree *macsec_tree, *tci_tree;
tvbuff_t *next_tvb;
tci_an_field = tvb_get_guint8(tvb, 0);
if ((tci_an_field & TCI_V_MASK) != 0) { /* version must be zero */
return 0;
}
if (tci_an_field & TCI_SC_MASK) {
sectag_length = 14;
} else {
sectag_length = 6;
}
/* Check for short length */
if (tvb_captured_length(tvb) <= (sectag_length + icv_length)) {
return 0;
}
data_offset = sectag_length;
data_length = tvb_captured_length(tvb) - sectag_length - icv_length;
icv_offset = data_length + data_offset;
next_tvb = tvb_new_subset_length(tvb, data_offset, data_length);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MACSEC");
col_set_str(pinfo->cinfo, COL_INFO, "MACsec frame");
if (tree) {
macsec_item = proto_tree_add_item(tree,
proto_macsec, tvb, 0, sectag_length, ENC_NA);
macsec_tree = proto_item_add_subtree(macsec_item, ett_macsec);
tci_item = proto_tree_add_uint_format(macsec_tree, hf_macsec_TCI, tvb,
sectag_offset, 1, tci_an_field,
"TCI=0x%02x: V=%d, ES=%d, SC=%d, SCB=%d, E=%d, C=%d, AN=%d",
tci_an_field,
((TCI_V_MASK & tci_an_field) ? 1:0),
((TCI_ES_MASK & tci_an_field) ? 1:0),
((TCI_SC_MASK & tci_an_field) ? 1:0),
((TCI_SCB_MASK & tci_an_field) ? 1:0),
((TCI_E_MASK & tci_an_field) ? 1:0),
((TCI_C_MASK & tci_an_field) ? 1:0),
(TCI_AN_MASK & tci_an_field));
tci_tree = proto_item_add_subtree(tci_item, ett_macsec_tci);
proto_tree_add_item(tci_tree, hf_macsec_TCI_V, tvb, sectag_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tci_tree, hf_macsec_TCI_ES, tvb, sectag_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tci_tree, hf_macsec_TCI_SC, tvb, sectag_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tci_tree, hf_macsec_TCI_SCB, tvb, sectag_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tci_tree, hf_macsec_TCI_E, tvb, sectag_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tci_tree, hf_macsec_TCI_C, tvb, sectag_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tci_tree, hf_macsec_AN, tvb, sectag_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(macsec_tree, hf_macsec_SL, tvb, sectag_offset + 1, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(macsec_tree, hf_macsec_PN, tvb, sectag_offset + 2, 4, ENC_BIG_ENDIAN);
if (sectag_length == 14) {
proto_tree_add_item(macsec_tree, hf_macsec_SCI_System_identifier,
tvb, sectag_offset + 6, 6, ENC_NA);
proto_tree_add_item(macsec_tree, hf_macsec_SCI_port_number, tvb,
sectag_offset + 12, 2, ENC_BIG_ENDIAN);
}
call_data_dissector(next_tvb, pinfo, tree);
proto_tree_add_item(macsec_tree, hf_macsec_ICV, tvb, icv_offset,
icv_length, ENC_NA);
}
return tvb_captured_length(tvb);
}
void
proto_register_macsec(void)
{
static hf_register_info hf[] = {
{ &hf_macsec_TCI, { "TAG Control Information", "macsec.TCI",FT_UINT8,
BASE_HEX, NULL, 0xfc, NULL, HFILL} },
{ &hf_macsec_TCI_V, { "VER", "macsec.TCI.V", FT_UINT8, BASE_HEX,
NULL, 0x80, NULL, HFILL} },
{ &hf_macsec_TCI_ES, { "ES", "macsec.TCI.ES", FT_UINT8, BASE_HEX, NULL,
0x40, NULL, HFILL} },
{ &hf_macsec_TCI_SC, { "SC", "macsec.TCI.SC", FT_UINT8, BASE_HEX, NULL,
0x20, NULL, HFILL} },
{ &hf_macsec_TCI_SCB, { "SCB", "macsec.TCI.SCB", FT_UINT8, BASE_HEX,
NULL, 0x10, NULL, HFILL} },
{ &hf_macsec_TCI_E, { "E", "macsec.TCI.E", FT_UINT8, BASE_HEX, NULL,
0x08, NULL, HFILL} },
{ &hf_macsec_TCI_C, { "C", "macsec.TCI.C", FT_UINT8, BASE_HEX, NULL,
0x04, NULL, HFILL} },
{ &hf_macsec_AN, { "AN", "macsec.AN", FT_UINT8,
BASE_HEX, NULL, 0x03, NULL, HFILL} },
{ &hf_macsec_SL, { "Short length", "macsec.SL", FT_UINT8, BASE_DEC,
NULL, 0xFF, NULL, HFILL} },
{ &hf_macsec_PN, { "Packet number", "macsec.PN", FT_UINT32, BASE_DEC,
NULL, 0xFFFFFFFF, NULL, HFILL} },
{ &hf_macsec_SCI_System_identifier,
{ "System Identifier", "macsec.SCI.SytemIdentifier",
FT_ETHER, BASE_NONE, NULL, 0x00, NULL, HFILL} },
{ &hf_macsec_SCI_port_number,
{ "Port number", "macsec.SCI.port_number",
FT_UINT16, BASE_DEC, NULL, 0xFFFF, NULL, HFILL} },
{ &hf_macsec_ICV, { "ICV", "macsec.ICV",
FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL} }
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_macsec,
&ett_macsec_tci
};
/* Register the protocol name and description */
proto_macsec = proto_register_protocol("802.1AE Secure tag", "macsec", "macsec");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_macsec, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_macsec(void)
{
dissector_handle_t macsec_handle;
macsec_handle = create_dissector_handle(dissect_macsec, proto_macsec);
dissector_add_uint("ethertype", ETHERTYPE_MACSEC, macsec_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:
*/
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