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|
/* packet-esl.c
* Routines for EtherCAT Switch Link disassembly
*
* Copyright (c) 2007 by Beckhoff Automation GmbH
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1999 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/prefs.h>
void proto_register_esl(void);
#if 0
/* XXX: using bitfields is compiler dependent: See README.developer */
typedef union _EslFlagsUnion
{
struct
{
guint16 port7 : 1;
guint16 port6 : 1;
guint16 port5 : 1;
guint16 port4 : 1;
guint16 port3 : 1;
guint16 port2 : 1;
guint16 port1 : 1;
guint16 port0 : 1;
guint16 extended : 1;
guint16 port11 : 1;
guint16 port10 : 1;
guint16 alignError : 1;
guint16 crcError : 1;
guint16 timeStampEna : 1;
guint16 port9 : 1;
guint16 port8 : 1;
}d;
struct
{
guint8 loPorts : 1;
guint8 flagsHiPorts : 1;
}lo_hi_flags;
guint flags;
} EslFlagsUnion;
#endif
#define esl_port7_bitmask 0x0001
#define esl_port6_bitmask 0x0002
#define esl_port5_bitmask 0x0004
#define esl_port4_bitmask 0x0008
#define esl_port3_bitmask 0x0010
#define esl_port2_bitmask 0x0020
#define esl_port1_bitmask 0x0040
#define esl_port0_bitmask 0x0080
#define esl_extended_bitmask 0x0100
#define esl_port11_bitmask 0x0200
#define esl_port10_bitmask 0x0400
#define esl_alignError_bitmask 0x0800
#define esl_crcError_bitmask 0x1000
#define esl_timeStampEna_bitmask 0x2000
#define esl_port9_bitmask 0x4000
#define esl_port8_bitmask 0x8000
#if 0
typedef struct _EslHeader
{
guint8 eslCookie[6]; /* 01 01 05 10 00 00 */
EslFlagsUnion flags;
guint64 timeStamp;
} EslHeader, *PEslHeader;
#endif
#define SIZEOF_ESLHEADER 16
static dissector_handle_t eth_withoutfcs_handle;
void proto_reg_handoff_esl(void);
/* Define the esl proto */
int proto_esl = -1;
static int ett_esl = -1;
static int hf_esl_timestamp = -1;
static int hf_esl_port = -1;
static int hf_esl_crcerror = -1;
static int hf_esl_alignerror = -1;
/* Note: using external tfs strings apparently doesn't work in a plugin */
static const true_false_string flags_yes_no = {
"yes",
"no"
};
#if 0
/* XXX: using bitfields is compiler dependent: See README.developer */
static guint16 flags_to_port(guint16 flagsValue) {
EslFlagsUnion flagsUnion;
flagsUnion.flags = flagsValue;
if ( flagsUnion.d.port0 )
return 0;
else if ( flagsUnion.d.port1 )
return 1;
else if ( flagsUnion.d.port2 )
return 2;
else if ( flagsUnion.d.port3 )
return 3;
else if ( flagsUnion.d.port4 )
return 4;
else if ( flagsUnion.d.port5 )
return 5;
else if ( flagsUnion.d.port6 )
return 6;
else if ( flagsUnion.d.port7 )
return 7;
else if ( flagsUnion.d.port8 )
return 8;
else if ( flagsUnion.d.port9 )
return 9;
return -1;
}
#endif
static guint16 flags_to_port(guint16 flagsValue) {
if ( (flagsValue & esl_port0_bitmask) != 0 )
return 0;
else if ( (flagsValue & esl_port1_bitmask) != 0 )
return 1;
else if ( (flagsValue & esl_port2_bitmask) != 0 )
return 2;
else if ( (flagsValue & esl_port3_bitmask) != 0 )
return 3;
else if ( (flagsValue & esl_port4_bitmask) != 0 )
return 4;
else if ( (flagsValue & esl_port5_bitmask) != 0 )
return 5;
else if ( (flagsValue & esl_port6_bitmask) != 0 )
return 6;
else if ( (flagsValue & esl_port7_bitmask) != 0 )
return 7;
else if ( (flagsValue & esl_port8_bitmask) != 0 )
return 8;
else if ( (flagsValue & esl_port9_bitmask) != 0 )
return 9;
else if ( (flagsValue & esl_port10_bitmask) != 0 )
return 10;
else if ( (flagsValue & esl_port11_bitmask) != 0 )
return 11;
return -1;
}
/*esl*/
static int
dissect_esl_header(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void* data _U_) {
proto_item *ti = NULL;
proto_tree *esl_header_tree;
gint offset = 0;
guint esl_length = tvb_reported_length(tvb);
if ( esl_length >= SIZEOF_ESLHEADER )
{
if (tree)
{
guint16 flags;
ti = proto_tree_add_item(tree, proto_esl, tvb, 0, SIZEOF_ESLHEADER, ENC_NA);
esl_header_tree = proto_item_add_subtree(ti, ett_esl);
offset+=6;
flags = tvb_get_letohs(tvb, offset);
proto_tree_add_uint(esl_header_tree, hf_esl_port, tvb, offset, 2, flags_to_port(flags));
proto_tree_add_item(esl_header_tree, hf_esl_alignerror, tvb, offset, 2, ENC_LITTLE_ENDIAN);
proto_tree_add_item(esl_header_tree, hf_esl_crcerror, tvb, offset, 2, ENC_LITTLE_ENDIAN);
offset+=2;
proto_tree_add_item(esl_header_tree, hf_esl_timestamp, tvb, offset, 8, ENC_LITTLE_ENDIAN);
}
}
return tvb_captured_length(tvb);
}
typedef struct _ref_time_frame_info
{
frame_data *fd;
guint64 esl_ts;
nstime_t abs_ts;
guint32 num;
} ref_time_frame_info;
static ref_time_frame_info ref_time_frame;
static gboolean is_esl_header(tvbuff_t *tvb, gint offset)
{
return tvb_get_guint8(tvb, offset) == 0x01 &&
tvb_get_guint8(tvb, offset+1) == 0x01 &&
tvb_get_guint8(tvb, offset+2) == 0x05 &&
(tvb_get_guint8(tvb, offset+3) == 0x10 ||tvb_get_guint8(tvb, offset+3) == 0x11)&&
tvb_get_guint8(tvb, offset+4) == 0x00 &&
tvb_get_guint8(tvb, offset+5) == 0x00;
}
static void modify_times(tvbuff_t *tvb, gint offset, packet_info *pinfo)
{
if ( ref_time_frame.fd == NULL )
{
ref_time_frame.esl_ts = tvb_get_letoh64(tvb, offset+8);
ref_time_frame.fd = pinfo->fd;
ref_time_frame.num = pinfo->num;
ref_time_frame.abs_ts = pinfo->abs_ts;
}
else if ( !pinfo->fd->visited )
{
guint64 nsecs = tvb_get_letoh64(tvb, offset+8) - ref_time_frame.esl_ts;
guint64 secs = nsecs/1000000000;
nstime_t ts;
nstime_t ts_delta;
ts.nsecs = ref_time_frame.abs_ts.nsecs + (int)(nsecs-(secs*1000000000));
if ( ts.nsecs > 1000000000 )
{
ts.nsecs-=1000000000;
secs++;
}
ts.secs = ref_time_frame.abs_ts.secs+(int)secs;
nstime_delta(&ts_delta, &ts, &pinfo->abs_ts);
pinfo->abs_ts = ts;
pinfo->fd->abs_ts = ts;
nstime_add(&pinfo->rel_ts, &ts_delta);
}
}
static gboolean
dissect_esl_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
static gboolean in_heur = FALSE;
gboolean result;
tvbuff_t *next_tvb;
guint esl_length = tvb_captured_length(tvb);
if ( in_heur )
return FALSE;
in_heur = TRUE;
/*TRY */
{
if ( ref_time_frame.fd != NULL && !pinfo->fd->visited && pinfo->num <= ref_time_frame.num )
ref_time_frame.fd = NULL;
/* Check that there's enough data */
if ( esl_length < SIZEOF_ESLHEADER )
return FALSE;
/* check for Esl frame, this has a unique destination MAC from Beckhoff range
First 6 bytes must be: 01 01 05 10 00 00 */
if ( is_esl_header(tvb, 0) )
{
dissect_esl_header(tvb, pinfo, tree, data);
if ( eth_withoutfcs_handle != NULL )
{
next_tvb = tvb_new_subset_remaining(tvb, SIZEOF_ESLHEADER);
call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree);
}
modify_times(tvb, 0, pinfo);
result = TRUE;
}
else if ( is_esl_header(tvb, esl_length-SIZEOF_ESLHEADER) )
{
if ( eth_withoutfcs_handle != NULL )
{
next_tvb = tvb_new_subset_length(tvb, 0, esl_length-SIZEOF_ESLHEADER);
call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree);
}
next_tvb = tvb_new_subset_length(tvb, esl_length-SIZEOF_ESLHEADER, SIZEOF_ESLHEADER);
dissect_esl_header(next_tvb, pinfo, tree, data);
modify_times(tvb, esl_length-SIZEOF_ESLHEADER, pinfo);
result = TRUE;
}
else
{
result = FALSE;
}
}
/*CATCH_ALL{
in_heur = FALSE;
RETHROW;
}ENDTRY;*/
in_heur = FALSE;
return result;
}
void
proto_register_esl(void) {
static hf_register_info hf[] = {
{ &hf_esl_port,
{ "Port", "esl.port",
FT_UINT16, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
{ &hf_esl_crcerror,
{ "Crc Error", "esl.crcerror",
FT_BOOLEAN, 16, TFS(&flags_yes_no), esl_crcError_bitmask,
NULL, HFILL }
},
{ &hf_esl_alignerror,
{ "Alignment Error", "esl.alignerror",
FT_BOOLEAN, 16, TFS(&flags_yes_no), esl_alignError_bitmask,
NULL, HFILL }
},
{ &hf_esl_timestamp,
{ "timestamp", "esl.timestamp",
FT_UINT64, BASE_HEX, NULL, 0x0,
NULL, HFILL }
},
};
static gint *ett[] = {
&ett_esl,
};
module_t *esl_module;
proto_esl = proto_register_protocol("EtherCAT Switch Link",
"ESL","esl");
esl_module = prefs_register_protocol_obsolete(proto_esl);
prefs_register_obsolete_preference(esl_module, "enable");
proto_register_field_array(proto_esl,hf,array_length(hf));
proto_register_subtree_array(ett,array_length(ett));
register_dissector("esl", dissect_esl_header, proto_esl);
}
void
proto_reg_handoff_esl(void) {
static gboolean initialized = FALSE;
if (!initialized) {
eth_withoutfcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_esl);
heur_dissector_add("eth", dissect_esl_heur, "EtherCAT over Ethernet", "esl_eth", proto_esl, HEURISTIC_DISABLE);
initialized = TRUE;
}
}
/*
* 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:
*/
|
