![Guy Harris](/assets/img/avatar_default.png)
header are unsigned - make them so. While we're at it, make them "guint8" rather than "guchar", to make it explicit that they're one byte long. svn path=/trunk/; revision=7650
693 lines
25 KiB
C
693 lines
25 KiB
C
/* packet-mbtcp.c
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* Routines for Modbus/TCP dissection
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* By Riaan Swart <rswart@cs.sun.ac.za>
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* Copyright 2001, Institute for Applied Computer Science
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* University of Stellenbosch
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*
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* See
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*
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* http://www.modicon.com/openmbus/
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*
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* for information on Modbus/TCP.
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*
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* $Id: packet-mbtcp.c,v 1.14 2003/05/08 00:42:28 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <glib.h>
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#include <epan/packet.h>
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#define DEBUG
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#define TCP_PORT_MBTCP 502 /* Modbus/TCP located on TCP port 502 */
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/* Modbus protocol function codes */
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#define read_coils 1
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#define read_input_discretes 2
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#define read_mult_regs 3
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#define read_input_regs 4
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#define write_coil 5
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#define write_single_reg 6
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#define read_except_stat 7
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#define diagnostics 8
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#define program_484 9
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#define poll_484 10
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#define get_comm_event_ctrs 11
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#define get_comm_event_log 12
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#define program_584_984 13
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#define poll_584_984 14
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#define force_mult_coils 15
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#define write_mult_regs 16
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#define report_slave_id 17
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#define program_884_u84 18
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#define reset_comm_link 19
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#define read_genl_ref 20
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#define write_genl_ref 21
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#define mask_write_reg 22
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#define read_write_reg 23
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#define read_fifo_queue 24
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#define program_ConCept 40
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#define firmware_replace 125
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#define program_584_984_2 126
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#define report_local_addr_mb 127
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/* Modbus protocol exception codes */
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#define illegal_function 0x01
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#define illegal_address 0x02
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#define illegal_value 0x03
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#define illegal_response 0x04
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#define acknowledge 0x05
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#define slave_busy 0x06
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#define negative_ack 0x07
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#define memory_err 0x08
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#define gateway_unavailable 0x0a
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#define gateway_trgt_fail 0x0b
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/* return codes of function classifying packets as query/response */
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#define query_packet 0
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#define response_packet 1
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#define cannot_classify 2
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/* Modbus header */
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typedef struct _modbus_hdr {
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guint8 unit_id; /* unit identifier (previously slave addr) */
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guint8 function_code; /* Modbus function code */
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} modbus_hdr;
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/* Modbus/TCP header, containing the Modbus header */
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typedef struct _mbtcp_hdr {
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guint16 transaction_id; /* copied by svr, usually 0 */
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guint16 protocol_id; /* always 0 */
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guint16 len; /* len of data that follows */
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modbus_hdr mdbs_hdr; /* mdbus hdr directly after mdbs/tcp hdr *
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* in packet */
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} mbtcp_hdr;
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/* Initialize the protocol and registered fields */
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static int proto_mbtcp = -1;
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static int hf_mbtcp_transid = -1;
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static int hf_mbtcp_protid = -1;
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static int hf_mbtcp_len = -1;
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static int hf_mbtcp_unitid = -1;
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static int hf_mbtcp_functioncode = -1;
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static int hf_modbus_reference = -1;
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static int hf_modbus_lreference = -1;
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static int hf_modbus_reftype = -1;
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static int hf_modbus_readref = -1;
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static int hf_modbus_writeref = -1;
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static int hf_modbus_wordcnt = -1;
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static int hf_modbus_readwordcnt = -1;
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static int hf_modbus_writewordcnt = -1;
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static int hf_modbus_bytecnt = -1;
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static int hf_modbus_lbytecnt = -1;
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static int hf_modbus_bitcnt = -1;
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static int hf_modbus_exceptioncode = -1;
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static int hf_modbus_andmask = -1;
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static int hf_modbus_ormask = -1;
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/* Initialize the subtree pointers */
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static gint ett_mbtcp = -1;
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static gint ett_modbus_hdr = -1;
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static gint ett_group_hdr = -1;
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static int
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classify_packet(packet_info *pinfo)
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{
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/* see if nature of packets can be derived from src/dst ports */
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/* if so, return as found */
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if ( ( 502 == pinfo->srcport && 502 != pinfo->destport ) ||
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( 502 != pinfo->srcport && 502 == pinfo->destport ) ) {
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/* the slave is receiving queries on port 502 */
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if ( 502 == pinfo->srcport )
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return response_packet;
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else if ( 502 == pinfo->destport )
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return query_packet;
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}
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/* else, cannot classify */
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return cannot_classify;
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}
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/* Translate function to string, as given on p6 of
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* "Open Modbus/TCP Specification", release 1 by Andy Swales. */
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static const value_string function_code_vals[] = {
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{ read_coils, "Read coils" },
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{ read_input_discretes, "Read input discretes" },
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{ read_mult_regs, "Read multiple registers" },
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{ read_input_regs, "Read input registers" },
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{ write_coil, "Write coil" },
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{ write_single_reg, "Write single register" },
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{ read_except_stat, "Read exception status" },
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{ diagnostics, "Diagnostics" },
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{ program_484, "Program (484)" },
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{ poll_484, "Poll (484)" },
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{ get_comm_event_ctrs, "Get Comm. Event Counters" },
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{ get_comm_event_log, "Get Comm. Event Log" },
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{ program_584_984, "Program (584/984)" },
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{ poll_584_984, "Poll (584/984)" },
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{ force_mult_coils, "Force Multiple Coils" },
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{ write_mult_regs, "Write Multiple Registers" },
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{ report_slave_id, "Report Slave ID" },
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{ program_884_u84, "Program 884/u84" },
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{ reset_comm_link, "Reset Comm. Link (884/u84)" },
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{ read_genl_ref, "Read General Reference" },
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{ write_genl_ref, "Write General Reference" },
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{ mask_write_reg, "Mask Write Register" },
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{ read_write_reg, "Read Write Register" },
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{ read_fifo_queue, "Read FIFO Queue" },
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{ program_ConCept, "Program (ConCept)" },
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{ firmware_replace, "Firmware replacement" },
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{ program_584_984_2, "Program (584/984)" },
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{ report_local_addr_mb, "Report local address (Modbus)" },
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{ 0, NULL }
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};
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static const value_string exception_code_vals[] = {
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{ illegal_function, "Illegal function" },
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{ illegal_address, "Illegal data address" },
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{ illegal_value, "Illegal data value" },
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{ illegal_response, "Illegal response length" },
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{ acknowledge, "Acknowledge" },
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{ slave_busy, "Slave device busy" },
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{ negative_ack, "Negative acknowledge" },
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{ memory_err, "Memory parity error" },
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{ gateway_unavailable, "Gateway path unavailable" },
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{ gateway_trgt_fail, "Gateway target device failed to respond" },
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{ 0, NULL }
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};
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/* Code to actually dissect the packets */
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static void
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dissect_mbtcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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/* Set up structures needed to add the protocol subtree and manage it */
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mbtcp_hdr mh;
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proto_item *mi, *mf;
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proto_tree *mbtcp_tree, *modbus_tree, *group_tree;
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int offset, group_offset, packet_type;
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guint i;
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gint packet_len, payload_start, payload_len;
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char *func_string = "", pkt_type_str[9] = "";
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char err_str[100] = "";
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guint32 byte_cnt, group_byte_cnt, group_word_cnt;
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guint32 packet_num; /* num to uniquely identify different mbtcp
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* packets in one TCP packet */
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guint8 exception_code;
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gboolean exception_returned;
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/* Make entries in Protocol column on summary display */
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "Modbus/TCP");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_clear(pinfo->cinfo, COL_INFO);
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/* Make entries in Info column on summary display */
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offset = 0;
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tvb_memcpy(tvb, (guint8 *)&mh, offset, sizeof(mbtcp_hdr));
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mh.transaction_id = g_ntohs(mh.transaction_id);
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mh.protocol_id = g_ntohs(mh.protocol_id);
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mh.len = g_ntohs(mh.len);
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if ( mh.mdbs_hdr.function_code & 0x80 ) {
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exception_code = tvb_get_guint8(tvb, offset + sizeof(mbtcp_hdr));
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mh.mdbs_hdr.function_code ^= 0x80;
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exception_returned = TRUE;
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}
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else {
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exception_code = 0;
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exception_returned = FALSE;
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}
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func_string = val_to_str(mh.mdbs_hdr.function_code, function_code_vals,
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"Unknown function (%u)");
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if (check_col(pinfo->cinfo, COL_INFO))
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{
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packet_type = classify_packet(pinfo);
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switch ( packet_type ) {
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case query_packet : strcpy(pkt_type_str, "query");
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break;
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case response_packet : strcpy(pkt_type_str, "response");
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break;
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case cannot_classify : strcpy(err_str, "Unable to classify as query or response.");
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strcpy(pkt_type_str, "unknown");
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break;
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default :
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break;
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}
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if ( exception_returned )
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strcpy(err_str, "Exception returned ");
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col_add_fstr(pinfo->cinfo, COL_INFO,
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"%8s [%2u pkt(s)]: trans: %5u; unit: %3u, func: %3u: %s. %s",
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pkt_type_str, 1, mh.transaction_id, (unsigned char) mh.mdbs_hdr.unit_id,
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(unsigned char) mh.mdbs_hdr.function_code, func_string, err_str);
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}
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/* build up protocol tree and iterate over multiple packets */
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packet_num = 0;
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while (1) {
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packet_type = classify_packet(pinfo);
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packet_len = sizeof(mbtcp_hdr) - sizeof(modbus_hdr) + mh.len;
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/* if a tree exists, perform operations to add fields to it */
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if (tree) {
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mi = proto_tree_add_protocol_format(tree, proto_mbtcp, tvb, offset,
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packet_len, "Modbus/TCP");
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mbtcp_tree = proto_item_add_subtree(mi, ett_mbtcp);
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/* Add items to protocol tree specific to Modbus/TCP Modbus/TCP */
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proto_tree_add_uint(mbtcp_tree, hf_mbtcp_transid, tvb, offset, 2,
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mh.transaction_id);
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proto_tree_add_uint(mbtcp_tree, hf_mbtcp_protid, tvb, offset + 2, 2,
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mh.protocol_id);
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proto_tree_add_uint(mbtcp_tree, hf_mbtcp_len, tvb, offset + 4, 2,
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mh.len);
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/* Add items to protocol tree specific to Modbus generic */
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mf = proto_tree_add_text(mbtcp_tree, tvb, offset + 6, mh.len,
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"Modbus");
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modbus_tree = proto_item_add_subtree(mf, ett_modbus_hdr);
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proto_tree_add_uint(modbus_tree, hf_mbtcp_unitid, tvb, offset + 6, 1,
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mh.mdbs_hdr.unit_id);
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mi = proto_tree_add_uint(modbus_tree, hf_mbtcp_functioncode, tvb, offset + 7, 1,
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mh.mdbs_hdr.function_code);
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/** detail payload as a function of exception/function code */
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func_string = val_to_str(mh.mdbs_hdr.function_code,
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function_code_vals, "Unknown function");
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payload_start = offset + 8;
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payload_len = mh.len - sizeof(modbus_hdr);
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if (exception_returned) {
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proto_item_set_text(mi, "function %u: %s. Exception: %s",
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mh.mdbs_hdr.function_code,
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func_string,
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val_to_str(exception_code,
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exception_code_vals,
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"Unknown exception code (%u)"));
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proto_tree_add_uint(modbus_tree, hf_modbus_exceptioncode, tvb, payload_start, 1,
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exception_code);
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}
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else {
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proto_item_set_text(mi, "function %u: %s", mh.mdbs_hdr.function_code,
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func_string);
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switch (mh.mdbs_hdr.function_code) {
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case read_coils:
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case read_input_discretes:
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if (packet_type == query_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, FALSE);
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}
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else if (packet_type == response_packet) {
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byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
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proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1, byte_cnt);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 1, byte_cnt, "Data");
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}
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break;
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case read_mult_regs:
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case read_input_regs:
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if (packet_type == query_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, FALSE);
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}
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else if (packet_type == response_packet) {
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byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
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proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1, byte_cnt);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 1, byte_cnt, "Data");
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}
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break;
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case write_coil:
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if (packet_type == query_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 1, "Data");
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proto_tree_add_text(modbus_tree, tvb, payload_start + 3, 1, "Padding");
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}
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else if (packet_type == response_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 1, "Data");
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proto_tree_add_text(modbus_tree, tvb, payload_start + 3, 1, "Padding");
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}
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break;
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case write_single_reg:
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if (packet_type == query_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 2, "Data");
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}
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else if (packet_type == response_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 2, 2, "Data");
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}
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break;
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case read_except_stat:
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if (packet_type == response_packet)
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proto_tree_add_text(modbus_tree, tvb, payload_start, 1, "Data");
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break;
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case force_mult_coils:
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if (packet_type == query_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, FALSE);
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byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start + 4);
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proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start + 4, 1,
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byte_cnt);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 5, byte_cnt, "Data");
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}
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else if (packet_type == response_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, FALSE);
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}
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break;
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case write_mult_regs:
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if (packet_type == query_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, FALSE);
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byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start + 4);
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proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start + 4, 1,
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byte_cnt);
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proto_tree_add_text(modbus_tree, tvb, payload_start + 5, byte_cnt, "Data");
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}
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else if (packet_type == response_packet) {
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proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, FALSE);
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proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, FALSE);
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}
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break;
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case read_genl_ref:
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if (packet_type == query_packet) {
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byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
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proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1,
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byte_cnt);
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/* add subtrees to describe each group of packet */
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group_offset = payload_start + 1;
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for (i = 0; i < byte_cnt / 7; i++) {
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mi = proto_tree_add_text( modbus_tree, tvb, group_offset, 7,
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"Group %u", i);
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group_tree = proto_item_add_subtree(mi, ett_group_hdr);
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proto_tree_add_item(group_tree, hf_modbus_reftype, tvb, group_offset, 1, FALSE);
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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;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* move onto next packet (if there) */
|
|
offset += packet_len;
|
|
packet_num++;
|
|
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;
|
|
}
|
|
else
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
/* Register the protocol with Ethereal */
|
|
|
|
void
|
|
proto_register_modbus(void)
|
|
{
|
|
|
|
/* Setup list of header fields See Section 1.6.1 for details*/
|
|
static hf_register_info hf[] = {
|
|
/* Modbus/TCP header fields */
|
|
{ &hf_mbtcp_transid,
|
|
{ "transaction identifier", "modbus_tcp.trans_id",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"", HFILL }
|
|
},
|
|
{ &hf_mbtcp_protid,
|
|
{ "protocol identifier", "modbus_tcp.prot_id",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"", HFILL }
|
|
},
|
|
{ &hf_mbtcp_len,
|
|
{ "length", "modbus_tcp.len",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"", HFILL }
|
|
},
|
|
/* Modbus header fields */
|
|
{ &hf_mbtcp_unitid,
|
|
{ "unit identifier", "modbus_tcp.unit_id",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"", HFILL }
|
|
},
|
|
{ &hf_mbtcp_functioncode,
|
|
{ "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",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"", HFILL }
|
|
},
|
|
{ &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 }
|
|
}
|
|
};
|
|
|
|
/* Setup protocol subtree array */
|
|
static gint *ett[] = {
|
|
&ett_mbtcp,
|
|
&ett_modbus_hdr,
|
|
&ett_group_hdr
|
|
};
|
|
|
|
/* Register the protocol name and description */
|
|
proto_mbtcp = proto_register_protocol("Modbus/TCP", "Modbus/TCP", "mbtcp");
|
|
|
|
/* Required function calls to register the header fields and subtrees used */
|
|
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)
|
|
{
|
|
dissector_handle_t mbtcp_handle;
|
|
|
|
mbtcp_handle = create_dissector_handle(dissect_mbtcp, proto_mbtcp);
|
|
dissector_add("tcp.port", TCP_PORT_MBTCP, mbtcp_handle);
|
|
}
|