2001-04-24 19:29:14 +00:00
|
|
|
/* packet-mbtcp.c
|
|
|
|
* Routines for Modbus/TCP dissection
|
|
|
|
* By Riaan Swart <rswart@cs.sun.ac.za>
|
|
|
|
* Copyright 2001, Institute for Applied Computer Science
|
|
|
|
* University of Stellenbosch
|
|
|
|
*
|
|
|
|
* See
|
|
|
|
*
|
2001-04-24 19:31:33 +00:00
|
|
|
* http://www.modicon.com/openmbus/
|
2001-04-24 19:29:14 +00:00
|
|
|
*
|
|
|
|
* for information on Modbus/TCP.
|
|
|
|
*
|
2003-04-18 04:45:00 +00:00
|
|
|
* $Id: packet-mbtcp.c,v 1.13 2003/04/18 04:45:00 guy Exp $
|
2001-04-24 19:29:14 +00:00
|
|
|
*
|
|
|
|
* Ethereal - Network traffic analyzer
|
2001-04-24 19:31:33 +00:00
|
|
|
* By Gerald Combs <gerald@ethereal.com>
|
2001-04-24 19:29:14 +00:00
|
|
|
* Copyright 1998 Gerald Combs
|
2002-08-28 21:04:11 +00:00
|
|
|
*
|
2001-04-24 19:29:14 +00:00
|
|
|
* 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.
|
2002-08-28 21:04:11 +00:00
|
|
|
*
|
2001-04-24 19:29:14 +00:00
|
|
|
* 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.
|
2002-08-28 21:04:11 +00:00
|
|
|
*
|
2001-04-24 19:29:14 +00:00
|
|
|
* 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 <stdio.h>
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include <string.h>
|
|
|
|
|
|
|
|
#include <glib.h>
|
|
|
|
|
2002-01-21 07:37:49 +00:00
|
|
|
#include <epan/packet.h>
|
2001-04-24 19:29:14 +00:00
|
|
|
|
2002-08-28 21:04:11 +00:00
|
|
|
#define DEBUG
|
2001-04-24 19:29:14 +00:00
|
|
|
|
|
|
|
#define TCP_PORT_MBTCP 502 /* Modbus/TCP located on TCP port 502 */
|
|
|
|
|
|
|
|
/* Modbus protocol function codes */
|
2003-04-16 06:57:38 +00:00
|
|
|
#define read_coils 1
|
2001-04-24 19:29:14 +00:00
|
|
|
#define read_input_discretes 2
|
2003-04-16 06:57:38 +00:00
|
|
|
#define read_mult_regs 3
|
|
|
|
#define read_input_regs 4
|
|
|
|
#define write_coil 5
|
|
|
|
#define write_single_reg 6
|
|
|
|
#define read_except_stat 7
|
|
|
|
#define diagnostics 8
|
|
|
|
#define program_484 9
|
|
|
|
#define poll_484 10
|
2001-04-24 19:29:14 +00:00
|
|
|
#define get_comm_event_ctrs 11
|
2003-04-16 06:57:38 +00:00
|
|
|
#define get_comm_event_log 12
|
|
|
|
#define program_584_984 13
|
|
|
|
#define poll_584_984 14
|
|
|
|
#define force_mult_coils 15
|
|
|
|
#define write_mult_regs 16
|
|
|
|
#define report_slave_id 17
|
|
|
|
#define program_884_u84 18
|
|
|
|
#define reset_comm_link 19
|
|
|
|
#define read_genl_ref 20
|
|
|
|
#define write_genl_ref 21
|
|
|
|
#define mask_write_reg 22
|
|
|
|
#define read_write_reg 23
|
|
|
|
#define read_fifo_queue 24
|
|
|
|
#define program_ConCept 40
|
|
|
|
#define firmware_replace 125
|
|
|
|
#define program_584_984_2 126
|
2001-04-24 19:29:14 +00:00
|
|
|
#define report_local_addr_mb 127
|
|
|
|
|
|
|
|
/* Modbus protocol exception codes */
|
2003-04-16 06:57:38 +00:00
|
|
|
#define illegal_function 0x01
|
|
|
|
#define illegal_address 0x02
|
|
|
|
#define illegal_value 0x03
|
|
|
|
#define illegal_response 0x04
|
|
|
|
#define acknowledge 0x05
|
|
|
|
#define slave_busy 0x06
|
|
|
|
#define negative_ack 0x07
|
|
|
|
#define memory_err 0x08
|
2001-04-24 19:29:14 +00:00
|
|
|
#define gateway_unavailable 0x0a
|
2003-04-16 06:57:38 +00:00
|
|
|
#define gateway_trgt_fail 0x0b
|
2001-04-24 19:29:14 +00:00
|
|
|
|
|
|
|
/* return codes of function classifying packets as query/response */
|
2003-04-16 06:57:38 +00:00
|
|
|
#define query_packet 0
|
|
|
|
#define response_packet 1
|
|
|
|
#define cannot_classify 2
|
2001-04-24 19:29:14 +00:00
|
|
|
|
|
|
|
/* Modbus header */
|
|
|
|
typedef struct _modbus_hdr {
|
2003-04-16 06:57:38 +00:00
|
|
|
gchar unit_id; /* unit identifier (previously slave addr) */
|
|
|
|
gchar function_code; /* Modbus function code */
|
2001-04-24 19:29:14 +00:00
|
|
|
} modbus_hdr;
|
|
|
|
|
|
|
|
/* Modbus/TCP header, containing the Modbus header */
|
|
|
|
typedef struct _mbtcp_hdr {
|
2003-04-16 06:57:38 +00:00
|
|
|
guint16 transaction_id; /* copied by svr, usually 0 */
|
|
|
|
guint16 protocol_id; /* always 0 */
|
|
|
|
guint16 len; /* len of data that follows */
|
|
|
|
modbus_hdr mdbs_hdr; /* mdbus hdr directly after mdbs/tcp hdr *
|
|
|
|
* in packet */
|
2001-04-24 19:29:14 +00:00
|
|
|
} mbtcp_hdr;
|
|
|
|
|
|
|
|
/* Initialize the protocol and registered fields */
|
|
|
|
static int proto_mbtcp = -1;
|
|
|
|
static int hf_mbtcp_transid = -1;
|
|
|
|
static int hf_mbtcp_protid = -1;
|
|
|
|
static int hf_mbtcp_len = -1;
|
|
|
|
static int hf_mbtcp_unitid = -1;
|
|
|
|
static int hf_mbtcp_functioncode = -1;
|
2003-04-16 06:57:38 +00:00
|
|
|
static int hf_modbus_reference = -1;
|
|
|
|
static int hf_modbus_lreference = -1;
|
|
|
|
static int hf_modbus_reftype = -1;
|
|
|
|
static int hf_modbus_readref = -1;
|
|
|
|
static int hf_modbus_writeref = -1;
|
|
|
|
static int hf_modbus_wordcnt = -1;
|
|
|
|
static int hf_modbus_readwordcnt = -1;
|
|
|
|
static int hf_modbus_writewordcnt = -1;
|
|
|
|
static int hf_modbus_bytecnt = -1;
|
|
|
|
static int hf_modbus_lbytecnt = -1;
|
|
|
|
static int hf_modbus_bitcnt = -1;
|
|
|
|
static int hf_modbus_exceptioncode = -1;
|
|
|
|
static int hf_modbus_andmask = -1;
|
|
|
|
static int hf_modbus_ormask = -1;
|
2001-04-24 19:29:14 +00:00
|
|
|
|
|
|
|
/* Initialize the subtree pointers */
|
|
|
|
static gint ett_mbtcp = -1;
|
|
|
|
static gint ett_modbus_hdr = -1;
|
2003-04-16 06:57:38 +00:00
|
|
|
static gint ett_group_hdr = -1;
|
2002-08-28 21:04:11 +00:00
|
|
|
|
2001-04-24 19:29:14 +00:00
|
|
|
static int
|
|
|
|
classify_packet(packet_info *pinfo)
|
|
|
|
{
|
|
|
|
/* see if nature of packets can be derived from src/dst ports */
|
|
|
|
/* if so, return as found */
|
|
|
|
if ( ( 502 == pinfo->srcport && 502 != pinfo->destport ) ||
|
2003-04-16 06:57:38 +00:00
|
|
|
( 502 != pinfo->srcport && 502 == pinfo->destport ) ) {
|
2001-04-24 19:29:14 +00:00
|
|
|
/* the slave is receiving queries on port 502 */
|
2002-08-28 21:04:11 +00:00
|
|
|
if ( 502 == pinfo->srcport )
|
2001-04-24 19:29:14 +00:00
|
|
|
return response_packet;
|
2002-08-28 21:04:11 +00:00
|
|
|
else if ( 502 == pinfo->destport )
|
2001-04-24 19:29:14 +00:00
|
|
|
return query_packet;
|
|
|
|
}
|
|
|
|
/* else, cannot classify */
|
|
|
|
return cannot_classify;
|
|
|
|
}
|
|
|
|
|
2003-04-16 06:57:38 +00:00
|
|
|
/* Translate function to string, as given on p6 of
|
2001-04-24 19:29:14 +00:00
|
|
|
* "Open Modbus/TCP Specification", release 1 by Andy Swales. */
|
2003-04-16 06:57:38 +00:00
|
|
|
static const value_string function_code_vals[] = {
|
|
|
|
{ read_coils, "Read coils" },
|
|
|
|
{ read_input_discretes, "Read input discretes" },
|
|
|
|
{ read_mult_regs, "Read multiple registers" },
|
|
|
|
{ read_input_regs, "Read input registers" },
|
|
|
|
{ write_coil, "Write coil" },
|
|
|
|
{ write_single_reg, "Write single register" },
|
|
|
|
{ read_except_stat, "Read exception status" },
|
|
|
|
{ diagnostics, "Diagnostics" },
|
|
|
|
{ program_484, "Program (484)" },
|
|
|
|
{ poll_484, "Poll (484)" },
|
|
|
|
{ get_comm_event_ctrs, "Get Comm. Event Counters" },
|
|
|
|
{ get_comm_event_log, "Get Comm. Event Log" },
|
|
|
|
{ program_584_984, "Program (584/984)" },
|
|
|
|
{ poll_584_984, "Poll (584/984)" },
|
|
|
|
{ force_mult_coils, "Force Multiple Coils" },
|
|
|
|
{ write_mult_regs, "Write Multiple Registers" },
|
|
|
|
{ report_slave_id, "Report Slave ID" },
|
|
|
|
{ program_884_u84, "Program 884/u84" },
|
|
|
|
{ reset_comm_link, "Reset Comm. Link (884/u84)" },
|
|
|
|
{ read_genl_ref, "Read General Reference" },
|
|
|
|
{ write_genl_ref, "Write General Reference" },
|
|
|
|
{ mask_write_reg, "Mask Write Register" },
|
|
|
|
{ read_write_reg, "Read Write Register" },
|
|
|
|
{ read_fifo_queue, "Read FIFO Queue" },
|
|
|
|
{ program_ConCept, "Program (ConCept)" },
|
|
|
|
{ firmware_replace, "Firmware replacement" },
|
|
|
|
{ program_584_984_2, "Program (584/984)" },
|
|
|
|
{ report_local_addr_mb, "Report local address (Modbus)" },
|
|
|
|
{ 0, NULL }
|
|
|
|
};
|
|
|
|
|
|
|
|
static const value_string exception_code_vals[] = {
|
|
|
|
{ illegal_function, "Illegal function" },
|
|
|
|
{ illegal_address, "Illegal data address" },
|
|
|
|
{ illegal_value, "Illegal data value" },
|
|
|
|
{ illegal_response, "Illegal response length" },
|
|
|
|
{ acknowledge, "Acknowledge" },
|
|
|
|
{ slave_busy, "Slave device busy" },
|
|
|
|
{ negative_ack, "Negative acknowledge" },
|
|
|
|
{ memory_err, "Memory parity error" },
|
|
|
|
{ gateway_unavailable, "Gateway path unavailable" },
|
|
|
|
{ gateway_trgt_fail, "Gateway target device failed to respond" },
|
|
|
|
{ 0, NULL }
|
|
|
|
};
|
2001-04-24 19:29:14 +00:00
|
|
|
|
|
|
|
/* Code to actually dissect the packets */
|
|
|
|
static void
|
|
|
|
dissect_mbtcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
|
|
{
|
|
|
|
/* Set up structures needed to add the protocol subtree and manage it */
|
|
|
|
mbtcp_hdr mh;
|
|
|
|
proto_item *mi, *mf;
|
2003-04-16 06:57:38 +00:00
|
|
|
proto_tree *mbtcp_tree, *modbus_tree, *group_tree;
|
|
|
|
int offset, group_offset, packet_type;
|
|
|
|
guint i;
|
|
|
|
gint packet_len, payload_start, payload_len;
|
|
|
|
char *func_string = "", pkt_type_str[9] = "";
|
|
|
|
char err_str[100] = "";
|
|
|
|
guint32 byte_cnt, group_byte_cnt, group_word_cnt;
|
|
|
|
guint32 packet_num; /* num to uniquely identify different mbtcp
|
|
|
|
* packets in one TCP packet */
|
|
|
|
guint8 exception_code;
|
|
|
|
gboolean exception_returned;
|
2002-08-28 21:04:11 +00:00
|
|
|
|
2001-04-24 19:29:14 +00:00
|
|
|
/* Make entries in Protocol column on summary display */
|
2002-08-28 21:04:11 +00:00
|
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
2001-12-10 00:26:21 +00:00
|
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Modbus/TCP");
|
2001-04-24 19:29:14 +00:00
|
|
|
|
2001-12-10 00:26:21 +00:00
|
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
2001-04-24 23:22:03 +00:00
|
|
|
|
2003-04-16 06:57:38 +00:00
|
|
|
/* Make entries in Info column on summary display */
|
|
|
|
offset = 0;
|
2001-04-24 19:29:14 +00:00
|
|
|
tvb_memcpy(tvb, (guint8 *)&mh, offset, sizeof(mbtcp_hdr));
|
2002-08-02 23:36:07 +00:00
|
|
|
mh.transaction_id = g_ntohs(mh.transaction_id);
|
|
|
|
mh.protocol_id = g_ntohs(mh.protocol_id);
|
|
|
|
mh.len = g_ntohs(mh.len);
|
2001-04-24 19:29:14 +00:00
|
|
|
if ( mh.mdbs_hdr.function_code & 0x80 ) {
|
2003-04-16 06:57:38 +00:00
|
|
|
exception_code = tvb_get_guint8(tvb, offset + sizeof(mbtcp_hdr));
|
2001-04-24 19:29:14 +00:00
|
|
|
mh.mdbs_hdr.function_code ^= 0x80;
|
2003-04-16 06:57:38 +00:00
|
|
|
exception_returned = TRUE;
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
exception_code = 0;
|
|
|
|
exception_returned = FALSE;
|
2001-04-24 19:29:14 +00:00
|
|
|
}
|
2003-04-16 06:57:38 +00:00
|
|
|
func_string = val_to_str(mh.mdbs_hdr.function_code, function_code_vals,
|
|
|
|
"Unknown function (%u)");
|
2001-12-10 00:26:21 +00:00
|
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
2001-04-24 23:22:03 +00:00
|
|
|
{
|
2001-04-24 19:29:14 +00:00
|
|
|
packet_type = classify_packet(pinfo);
|
|
|
|
switch ( packet_type ) {
|
2003-04-16 06:57:38 +00:00
|
|
|
case query_packet : strcpy(pkt_type_str, "query");
|
2001-04-24 19:29:14 +00:00
|
|
|
break;
|
2003-04-16 06:57:38 +00:00
|
|
|
case response_packet : strcpy(pkt_type_str, "response");
|
2001-04-24 19:29:14 +00:00
|
|
|
break;
|
|
|
|
case cannot_classify : strcpy(err_str, "Unable to classify as query or response.");
|
2003-04-16 06:57:38 +00:00
|
|
|
strcpy(pkt_type_str, "unknown");
|
2001-04-24 19:29:14 +00:00
|
|
|
break;
|
|
|
|
default :
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
if ( exception_returned )
|
|
|
|
strcpy(err_str, "Exception returned ");
|
2002-08-28 21:04:11 +00:00
|
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
|
|
"%8s [%2u pkt(s)]: trans: %5u; unit: %3u, func: %3u: %s. %s",
|
|
|
|
pkt_type_str, 1, mh.transaction_id, (unsigned char) mh.mdbs_hdr.unit_id,
|
2001-04-24 19:29:14 +00:00
|
|
|
(unsigned char) mh.mdbs_hdr.function_code, func_string, err_str);
|
2002-08-28 21:04:11 +00:00
|
|
|
}
|
2001-04-24 19:29:14 +00:00
|
|
|
|
2003-04-16 06:57:38 +00:00
|
|
|
/* build up protocol tree and iterate over multiple packets */
|
|
|
|
packet_num = 0;
|
|
|
|
while (1) {
|
2001-04-24 19:29:14 +00:00
|
|
|
packet_type = classify_packet(pinfo);
|
2003-04-16 06:57:38 +00:00
|
|
|
packet_len = sizeof(mbtcp_hdr) - sizeof(modbus_hdr) + mh.len;
|
2002-08-28 21:04:11 +00:00
|
|
|
|
2001-04-24 19:29:14 +00:00
|
|
|
/* if a tree exists, perform operations to add fields to it */
|
|
|
|
if (tree) {
|
2002-08-28 21:04:11 +00:00
|
|
|
mi = proto_tree_add_protocol_format(tree, proto_mbtcp, tvb, offset,
|
2001-04-24 19:29:14 +00:00
|
|
|
packet_len, "Modbus/TCP");
|
|
|
|
mbtcp_tree = proto_item_add_subtree(mi, ett_mbtcp);
|
2002-08-28 21:04:11 +00:00
|
|
|
|
2003-04-16 06:57:38 +00:00
|
|
|
/* Add items to protocol tree specific to Modbus/TCP Modbus/TCP */
|
2002-08-28 21:04:11 +00:00
|
|
|
proto_tree_add_uint(mbtcp_tree, hf_mbtcp_transid, tvb, offset, 2,
|
2001-04-24 19:29:14 +00:00
|
|
|
mh.transaction_id);
|
2002-08-28 21:04:11 +00:00
|
|
|
proto_tree_add_uint(mbtcp_tree, hf_mbtcp_protid, tvb, offset + 2, 2,
|
2001-04-24 19:29:14 +00:00
|
|
|
mh.protocol_id);
|
2002-08-28 21:04:11 +00:00
|
|
|
proto_tree_add_uint(mbtcp_tree, hf_mbtcp_len, tvb, offset + 4, 2,
|
2001-04-24 19:29:14 +00:00
|
|
|
mh.len);
|
2003-04-16 06:57:38 +00:00
|
|
|
|
|
|
|
/* Add items to protocol tree specific to Modbus generic */
|
|
|
|
mf = proto_tree_add_text(mbtcp_tree, tvb, offset + 6, mh.len,
|
2001-04-24 19:29:14 +00:00
|
|
|
"Modbus");
|
2002-08-28 21:04:11 +00:00
|
|
|
modbus_tree = proto_item_add_subtree(mf, ett_modbus_hdr);
|
2003-04-16 06:57:38 +00:00
|
|
|
proto_tree_add_uint(modbus_tree, hf_mbtcp_unitid, tvb, offset + 6, 1,
|
2001-04-24 19:29:14 +00:00
|
|
|
mh.mdbs_hdr.unit_id);
|
2003-04-16 06:57:38 +00:00
|
|
|
mi = proto_tree_add_uint(modbus_tree, hf_mbtcp_functioncode, tvb, offset + 7, 1,
|
2001-04-24 19:29:14 +00:00
|
|
|
mh.mdbs_hdr.function_code);
|
2003-04-16 06:57:38 +00:00
|
|
|
|
|
|
|
/** detail payload as a function of exception/function code */
|
|
|
|
func_string = val_to_str(mh.mdbs_hdr.function_code,
|
|
|
|
function_code_vals, "Unknown function");
|
|
|
|
payload_start = offset + 8;
|
|
|
|
payload_len = mh.len - sizeof(modbus_hdr);
|
|
|
|
if (exception_returned) {
|
|
|
|
proto_item_set_text(mi, "function %u: %s. Exception: %s",
|
|
|
|
mh.mdbs_hdr.function_code,
|
|
|
|
func_string,
|
|
|
|
val_to_str(exception_code,
|
|
|
|
exception_code_vals,
|
|
|
|
"Unknown exception code (%u)"));
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_exceptioncode, tvb, payload_start, 1,
|
|
|
|
exception_code);
|
|
|
|
}
|
|
|
|
else {
|
2002-08-28 21:04:11 +00:00
|
|
|
proto_item_set_text(mi, "function %u: %s", mh.mdbs_hdr.function_code,
|
2001-04-24 19:29:14 +00:00
|
|
|
func_string);
|
2003-04-16 06:57:38 +00:00
|
|
|
switch (mh.mdbs_hdr.function_code) {
|
|
|
|
|
|
|
|
case read_coils:
|
|
|
|
case read_input_discretes:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1, byte_cnt);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 1, byte_cnt, "Data");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case read_mult_regs:
|
|
|
|
case read_input_regs:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1, byte_cnt);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 1, byte_cnt, "Data");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case write_coil:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 1, "Data");
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 3, 1, "Padding");
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 1, "Data");
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 3, 1, "Padding");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case write_single_reg:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 2, "Data");
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 2, "Data");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case read_except_stat:
|
|
|
|
if (packet_type == response_packet)
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start, 1, "Data");
|
|
|
|
break;
|
|
|
|
|
|
|
|
case force_mult_coils:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start + 4);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start + 4, 1,
|
|
|
|
byte_cnt);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 5, byte_cnt, "Data");
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case write_mult_regs:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start + 4);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start + 4, 1,
|
|
|
|
byte_cnt);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 5, byte_cnt, "Data");
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case read_genl_ref:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1,
|
|
|
|
byte_cnt);
|
|
|
|
|
|
|
|
/* add subtrees to describe each group of packet */
|
|
|
|
group_offset = payload_start + 1;
|
|
|
|
for (i = 0; i < byte_cnt / 7; i++) {
|
|
|
|
mi = proto_tree_add_text( modbus_tree, tvb, group_offset, 7,
|
|
|
|
"Group %u", i);
|
|
|
|
group_tree = proto_item_add_subtree(mi, ett_group_hdr);
|
|
|
|
proto_tree_add_item(group_tree, hf_modbus_reftype, tvb, group_offset, 1, FALSE);
|
|
|
|
proto_tree_add_item(group_tree, hf_modbus_lreference, tvb, group_offset + 1, 4, FALSE);
|
|
|
|
proto_tree_add_item(group_tree, hf_modbus_wordcnt, tvb, group_offset + 5, 2, FALSE);
|
|
|
|
group_offset += 7;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1,
|
|
|
|
byte_cnt);
|
|
|
|
|
|
|
|
/* add subtrees to describe each group of packet */
|
|
|
|
group_offset = payload_start + 1;
|
|
|
|
i = 0;
|
|
|
|
while (byte_cnt > 0) {
|
|
|
|
group_byte_cnt = (guint32)tvb_get_guint8(tvb, group_offset);
|
|
|
|
mi = proto_tree_add_text( modbus_tree, tvb, group_offset, group_byte_cnt + 1,
|
|
|
|
"Group %u", i);
|
|
|
|
group_tree = proto_item_add_subtree(mi, ett_group_hdr);
|
|
|
|
proto_tree_add_uint(group_tree, hf_modbus_bytecnt, tvb, group_offset, 1,
|
|
|
|
group_byte_cnt);
|
|
|
|
proto_tree_add_item(group_tree, hf_modbus_reftype, tvb, group_offset + 1, 1, FALSE);
|
|
|
|
proto_tree_add_text(group_tree, tvb, group_offset + 2, group_byte_cnt - 1, "Data");
|
|
|
|
group_offset += (group_byte_cnt + 1);
|
|
|
|
byte_cnt -= (group_byte_cnt + 1);
|
|
|
|
i++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case write_genl_ref:
|
|
|
|
if ((packet_type == query_packet) || (packet_type == response_packet)) {
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1,
|
|
|
|
byte_cnt);
|
|
|
|
|
|
|
|
/* add subtrees to describe each group of packet */
|
|
|
|
group_offset = payload_start + 1;
|
|
|
|
i = 0;
|
|
|
|
while (byte_cnt > 0) {
|
|
|
|
group_word_cnt = tvb_get_ntohs(tvb, group_offset + 5);
|
|
|
|
group_byte_cnt = (2 * group_word_cnt) + 7;
|
|
|
|
mi = proto_tree_add_text( modbus_tree, tvb, group_offset,
|
|
|
|
group_byte_cnt, "Group %u", i);
|
|
|
|
group_tree = proto_item_add_subtree(mi, ett_group_hdr);
|
|
|
|
proto_tree_add_item(group_tree, hf_modbus_reftype, tvb, group_offset, 1, FALSE);
|
|
|
|
proto_tree_add_item(group_tree, hf_modbus_lreference, tvb, group_offset + 1, 4, FALSE);
|
|
|
|
proto_tree_add_uint(group_tree, hf_modbus_wordcnt, tvb, group_offset + 5, 2,
|
|
|
|
group_word_cnt);
|
|
|
|
proto_tree_add_text(group_tree, tvb, group_offset + 7, group_byte_cnt - 7, "Data");
|
|
|
|
group_offset += group_byte_cnt;
|
|
|
|
byte_cnt -= group_byte_cnt;
|
|
|
|
i++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case mask_write_reg:
|
|
|
|
if ((packet_type == query_packet) || (packet_type == response_packet)) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_andmask, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_ormask, tvb, payload_start + 4, 2, FALSE);
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case read_write_reg:
|
|
|
|
if (packet_type == query_packet) {
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_readref, tvb, payload_start, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_readwordcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_writeref, tvb, payload_start + 4, 2, FALSE);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_writewordcnt, tvb, payload_start + 6, 2, FALSE);
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start + 8);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start + 8, 1,
|
|
|
|
byte_cnt);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 9, byte_cnt, "Data");
|
|
|
|
}
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1,
|
|
|
|
byte_cnt);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 1, byte_cnt, "Data");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case read_fifo_queue:
|
|
|
|
if (packet_type == query_packet)
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
|
|
|
|
else if (packet_type == response_packet) {
|
|
|
|
byte_cnt = (guint32)tvb_get_ntohs(tvb, payload_start);
|
|
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_lbytecnt, tvb, payload_start, 2,
|
|
|
|
byte_cnt);
|
|
|
|
proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, FALSE);
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start + 4, byte_cnt - 2, "Data");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case diagnostics:
|
|
|
|
case program_484:
|
|
|
|
case poll_484:
|
|
|
|
case get_comm_event_ctrs:
|
|
|
|
case get_comm_event_log:
|
|
|
|
case program_584_984:
|
|
|
|
case poll_584_984:
|
|
|
|
case report_slave_id:
|
|
|
|
case program_884_u84:
|
|
|
|
case reset_comm_link:
|
|
|
|
case program_ConCept:
|
|
|
|
case firmware_replace:
|
|
|
|
case program_584_984_2:
|
|
|
|
case report_local_addr_mb:
|
|
|
|
/* these function codes are not part of the Modbus/TCP specification */
|
|
|
|
default:
|
|
|
|
if (payload_len > 0)
|
|
|
|
proto_tree_add_text(modbus_tree, tvb, payload_start, payload_len, "Data");
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
2001-04-24 19:29:14 +00:00
|
|
|
}
|
2003-04-16 06:57:38 +00:00
|
|
|
|
|
|
|
/* move onto next packet (if there) */
|
|
|
|
offset += packet_len;
|
2001-04-24 19:29:14 +00:00
|
|
|
packet_num++;
|
2003-04-16 06:57:38 +00:00
|
|
|
if (tvb_reported_length_remaining(tvb, offset) > 0) {
|
|
|
|
|
|
|
|
/* load header structure for next packet */
|
|
|
|
tvb_memcpy(tvb, (guint8 *)&mh, offset, sizeof(mbtcp_hdr));
|
|
|
|
mh.transaction_id = g_ntohs(mh.transaction_id);
|
|
|
|
mh.protocol_id = g_ntohs(mh.protocol_id);
|
|
|
|
mh.len = g_ntohs(mh.len);
|
|
|
|
|
|
|
|
if ( mh.mdbs_hdr.function_code & 0x80 ) {
|
|
|
|
exception_code = tvb_get_guint8(tvb, offset + sizeof(mbtcp_hdr));
|
|
|
|
mh.mdbs_hdr.function_code ^= 0x80;
|
|
|
|
exception_returned = TRUE;
|
|
|
|
} else
|
|
|
|
exception_returned = FALSE;
|
2001-04-24 19:29:14 +00:00
|
|
|
}
|
2003-04-16 06:57:38 +00:00
|
|
|
else
|
|
|
|
break;
|
2001-04-24 19:29:14 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Register the protocol with Ethereal */
|
|
|
|
|
|
|
|
void
|
|
|
|
proto_register_modbus(void)
|
2002-08-28 21:04:11 +00:00
|
|
|
{
|
2001-04-24 19:29:14 +00:00
|
|
|
|
|
|
|
/* Setup list of header fields See Section 1.6.1 for details*/
|
|
|
|
static hf_register_info hf[] = {
|
|
|
|
/* Modbus/TCP header fields */
|
|
|
|
{ &hf_mbtcp_transid,
|
2003-04-16 06:57:38 +00:00
|
|
|
{ "transaction identifier", "modbus_tcp.trans_id",
|
2002-08-28 21:04:11 +00:00
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
2001-06-18 02:18:27 +00:00
|
|
|
"", HFILL }
|
2001-04-24 19:29:14 +00:00
|
|
|
},
|
|
|
|
{ &hf_mbtcp_protid,
|
2003-04-16 06:57:38 +00:00
|
|
|
{ "protocol identifier", "modbus_tcp.prot_id",
|
2002-08-28 21:04:11 +00:00
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
2001-06-18 02:18:27 +00:00
|
|
|
"", HFILL }
|
2001-04-24 19:29:14 +00:00
|
|
|
},
|
|
|
|
{ &hf_mbtcp_len,
|
2003-04-16 06:57:38 +00:00
|
|
|
{ "length", "modbus_tcp.len",
|
2002-08-28 21:04:11 +00:00
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
2001-06-18 02:18:27 +00:00
|
|
|
"", HFILL }
|
2001-04-24 19:29:14 +00:00
|
|
|
},
|
|
|
|
/* Modbus header fields */
|
|
|
|
{ &hf_mbtcp_unitid,
|
2003-04-16 06:57:38 +00:00
|
|
|
{ "unit identifier", "modbus_tcp.unit_id",
|
2002-08-28 21:04:11 +00:00
|
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
2001-06-18 02:18:27 +00:00
|
|
|
"", HFILL }
|
2001-04-24 19:29:14 +00:00
|
|
|
},
|
|
|
|
{ &hf_mbtcp_functioncode,
|
2003-04-16 06:57:38 +00:00
|
|
|
{ "function code", "modbus_tcp.func_code",
|
|
|
|
FT_UINT8, BASE_DEC, VALS(function_code_vals), 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_reference,
|
|
|
|
{ "reference number", "modbus_tcp.reference_num",
|
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_lreference,
|
|
|
|
{ "reference number (32 bit)", "modbus_tcp.reference_num_32",
|
|
|
|
FT_UINT32, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_reftype,
|
|
|
|
{ "reference type", "modbus_tcp.reference_type",
|
2002-08-28 21:04:11 +00:00
|
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
2001-06-18 02:18:27 +00:00
|
|
|
"", HFILL }
|
2003-04-16 06:57:38 +00:00
|
|
|
},
|
|
|
|
{ &hf_modbus_readref,
|
|
|
|
{ "read reference number", "modbus_tcp.read_reference_num",
|
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_writeref,
|
|
|
|
{ "write reference number", "modbus_tcp.write_reference_num",
|
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_wordcnt,
|
|
|
|
{ "word count", "modbus_tcp.word_cnt",
|
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_readwordcnt,
|
|
|
|
{ "read word count", "modbus_tcp.read_word_cnt",
|
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_writewordcnt,
|
|
|
|
{ "write word count", "modbus_tcp.write_word_cnt",
|
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_bitcnt,
|
|
|
|
{ "bit count", "modbus_tcp.bit_cnt",
|
|
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_bytecnt,
|
|
|
|
{ "byte count", "modbus_tcp.byte_cnt",
|
|
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_lbytecnt,
|
|
|
|
{ "byte count (16-bit)", "modbus_tcp.byte_cnt_16",
|
|
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_exceptioncode,
|
|
|
|
{ "exception code", "modbus_tcp.exception_code",
|
|
|
|
FT_UINT8, BASE_DEC, VALS(exception_code_vals), 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_andmask,
|
|
|
|
{ "AND mask", "modbus_tcp.and_mask",
|
|
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
|
|
"", HFILL }
|
|
|
|
},
|
|
|
|
{ &hf_modbus_ormask,
|
|
|
|
{ "OR mask", "modbus_tcp.or_mask",
|
|
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
|
|
"", HFILL }
|
2001-04-24 19:29:14 +00:00
|
|
|
}
|
|
|
|
};
|
|
|
|
|
2003-04-16 06:57:38 +00:00
|
|
|
/* Setup protocol subtree array */
|
2001-04-24 19:29:14 +00:00
|
|
|
static gint *ett[] = {
|
|
|
|
&ett_mbtcp,
|
2003-04-16 06:57:38 +00:00
|
|
|
&ett_modbus_hdr,
|
|
|
|
&ett_group_hdr
|
2001-04-24 19:29:14 +00:00
|
|
|
};
|
|
|
|
|
2003-04-16 06:57:38 +00:00
|
|
|
/* Register the protocol name and description */
|
|
|
|
proto_mbtcp = proto_register_protocol("Modbus/TCP", "Modbus/TCP", "mbtcp");
|
2001-04-24 19:29:14 +00:00
|
|
|
|
2003-04-16 06:57:38 +00:00
|
|
|
/* Required function calls to register the header fields and subtrees used */
|
2001-04-24 19:29:14 +00:00
|
|
|
proto_register_field_array(proto_mbtcp, hf, array_length(hf));
|
|
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* If this dissector uses sub-dissector registration add a registration routine.
|
|
|
|
This format is required because a script is used to find these routines and
|
|
|
|
create the code that calls these routines.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
proto_reg_handoff_mbtcp(void)
|
|
|
|
{
|
2001-12-03 04:00:26 +00:00
|
|
|
dissector_handle_t mbtcp_handle;
|
|
|
|
|
|
|
|
mbtcp_handle = create_dissector_handle(dissect_mbtcp, proto_mbtcp);
|
|
|
|
dissector_add("tcp.port", TCP_PORT_MBTCP, mbtcp_handle);
|
2001-04-24 19:29:14 +00:00
|
|
|
}
|