forked from osmocom/wireshark
![Guy Harris](/assets/img/avatar_default.png)
It's not tied to the frame_data structure any more, so it belongs by itself. Clean up some #includes while we're at it; in particular, frame_data.h doesn't use anything related to tvbuffs, so don't have it gratuitiously include tvbuff.h. Change-Id: Ic32922d4a3840bac47007c5d4c546b8842245e0c Reviewed-on: https://code.wireshark.org/review/13518 Reviewed-by: Guy Harris <guy@alum.mit.edu>
2039 lines
88 KiB
C
2039 lines
88 KiB
C
/* packet-mbtcp.c
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* Routines for Modbus/TCP and Modbus/UDP 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 http://www.modbus.org/ for information on Modbus/TCP.
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*
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* Updated to v1.1b of the Modbus Application Protocol specification
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* Michael Mann * Copyright 2011
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*
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*****************************************************************************************************
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* A brief explanation of the distinction between Modbus/TCP and Modbus RTU over TCP:
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*
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* Consider a Modbus poll message: Unit 01, Scan Holding Register Address 0 for 30 Registers
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*
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* The Modbus/TCP message structure will follow the pattern below:
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* 00 00 00 00 00 06 01 03 00 00 00 1E
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* AA AA BB BB CC CC DD EE FF FF GG GG
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*
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* A = 16-bit Transaction Identifier (typically increments, or is locked at zero)
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* B = 16-bit Protocol Identifier (typically zero)
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* C = 16-bit Length of data payload following (and inclusive of) the length byte
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* D = 8-bit Unit / Slave ID
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* E = 8-bit Modbus Function Code
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* F = 16-bit Reference Number / Register Base Address
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* G = 16-bit Word Count / Number of Registers to scan
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*
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* A identical Modbus RTU (or Modbus RTU over TCP) message will overlay partially with the msg above
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* and contain 16-bit CRC at the end:
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* 00 00 00 00 00 06 01 03 00 00 00 1E -- -- (Modbus/TCP message, repeated from above)
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* -- -- -- -- -- -- 01 03 00 00 00 1E C5 C2 (Modbus RTU over TCP message, includes 16-bit CRC footer)
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* AA AA BB BB CC CC DD EE FF FF GG GG HH HH
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*
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* A = Not present in Modbus RTU message
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* B = Not present in Modbus RTU message
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* C = Not present in Modbus RTU message
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* D = 8-bit Unit / Slave ID
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* E = 8-bit Modbus Function Code
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* F = 16-bit Reference Number / Register Base Address
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* G = 16-bit Word Count / Number of Registers to scan
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* H = 16-bit CRC
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*
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*****************************************************************************************************
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <epan/packet.h>
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#include "packet-tcp.h"
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#include "packet-mbtcp.h"
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#include <epan/prefs.h>
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#include <epan/expert.h>
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#include <epan/crc16-tvb.h> /* For CRC verification */
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#include <epan/proto_data.h>
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void proto_register_modbus(void);
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void proto_reg_handoff_mbtcp(void);
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void proto_reg_handoff_mbrtu(void);
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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 proto_mbrtu = -1;
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static int proto_modbus = -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_modbus_request_frame = -1;
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static int hf_modbus_functioncode = -1;
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static int hf_modbus_reference = -1;
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static int hf_modbus_padding = -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_diag_sf = -1;
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static int hf_modbus_diag_return_query_data_request = -1;
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static int hf_modbus_diag_return_query_data_echo = -1;
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static int hf_modbus_diag_restart_communication_option = -1;
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static int hf_modbus_diag_return_diag_register = -1;
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static int hf_modbus_diag_ascii_input_delimiter = -1;
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static int hf_modbus_diag_clear_ctr_diag_reg = -1;
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static int hf_modbus_diag_return_bus_message_count = -1;
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static int hf_modbus_diag_return_bus_comm_error_count = -1;
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static int hf_modbus_diag_return_bus_exception_error_count = -1;
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static int hf_modbus_diag_return_slave_message_count = -1;
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static int hf_modbus_diag_return_no_slave_response_count = -1;
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static int hf_modbus_diag_return_slave_nak_count = -1;
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static int hf_modbus_diag_return_slave_busy_count = -1;
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static int hf_modbus_diag_return_bus_char_overrun_count = -1;
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static int hf_modbus_status = -1;
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static int hf_modbus_event = -1;
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static int hf_modbus_event_count = -1;
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static int hf_modbus_message_count = -1;
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static int hf_modbus_event_recv_comm_err = -1;
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static int hf_modbus_event_recv_char_over = -1;
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static int hf_modbus_event_recv_lo_mode = -1;
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static int hf_modbus_event_recv_broadcast = -1;
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static int hf_modbus_event_send_read_ex = -1;
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static int hf_modbus_event_send_slave_abort_ex = -1;
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static int hf_modbus_event_send_slave_busy_ex = -1;
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static int hf_modbus_event_send_slave_nak_ex = -1;
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static int hf_modbus_event_send_write_timeout = -1;
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static int hf_modbus_event_send_lo_mode = -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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static int hf_modbus_data = -1;
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static int hf_modbus_mei = -1;
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static int hf_modbus_read_device_id = -1;
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static int hf_modbus_object_id = -1;
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static int hf_modbus_num_objects = -1;
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static int hf_modbus_list_object_len = -1;
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static int hf_modbus_conformity_level = -1;
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static int hf_modbus_more_follows = -1;
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static int hf_modbus_next_object_id = -1;
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static int hf_modbus_object_str_value = -1;
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static int hf_modbus_object_value = -1;
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static int hf_modbus_reg16 = -1;
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static int hf_modbus_reg32 = -1;
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static int hf_mbrtu_unitid = -1;
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static int hf_mbrtu_crc16 = -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_mbrtu = -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 gint ett_events = -1;
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static gint ett_events_recv = -1;
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static gint ett_events_send = -1;
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static gint ett_device_id_objects = -1;
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static gint ett_device_id_object_items = -1;
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static expert_field ei_mbrtu_crc16_incorrect = EI_INIT;
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static expert_field ei_modbus_data_decode = EI_INIT;
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static dissector_handle_t modbus_handle;
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static dissector_handle_t mbtcp_handle;
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static dissector_handle_t mbrtu_handle;
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static dissector_table_t modbus_data_dissector_table;
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static dissector_table_t modbus_dissector_table;
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/* Globals for Modbus/TCP Preferences */
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static gboolean mbtcp_desegment = TRUE;
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static guint global_mbus_tcp_port = PORT_MBTCP; /* Port 502, by default */
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/* Globals for Modbus RTU over TCP Preferences */
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static gboolean mbrtu_desegment = TRUE;
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static guint global_mbus_rtu_port = PORT_MBRTU; /* 0, by default */
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static gboolean mbrtu_crc = FALSE;
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/* Globals for Modbus Preferences */
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static gint global_mbus_register_format = MODBUS_PREF_REGISTER_FORMAT_UINT16;
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static int
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classify_mbtcp_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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/* */
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/* XXX Update Oct 2012 - It can be difficult to determine if a packet is a query or response; some way to track */
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/* the Modbus/TCP transaction ID for each pair of messages would allow for detection based on a new seq. number. */
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/* Otherwise, we can stick with this method; a configurable port option has been added to allow for usage of */
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/* user ports either than the default of 502. */
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if (( pinfo->srcport == global_mbus_tcp_port ) && ( pinfo->destport != global_mbus_tcp_port ))
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return RESPONSE_PACKET;
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if (( pinfo->srcport != global_mbus_tcp_port ) && ( pinfo->destport == global_mbus_tcp_port ))
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return QUERY_PACKET;
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/* else, cannot classify */
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return CANNOT_CLASSIFY;
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}
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static int
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classify_mbrtu_packet(packet_info *pinfo, tvbuff_t *tvb)
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{
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guint8 func, len;
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func = tvb_get_guint8(tvb, 1);
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len = tvb_reported_length(tvb);
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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 (( pinfo->srcport == global_mbus_rtu_port ) && ( pinfo->destport != global_mbus_rtu_port ))
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return RESPONSE_PACKET;
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if (( pinfo->srcport != global_mbus_rtu_port ) && ( pinfo->destport == global_mbus_rtu_port ))
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return QUERY_PACKET;
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/* Special case for serial-captured packets that don't have an Ethernet header */
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/* Dig into these a little deeper to try to guess the message type */
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if (!pinfo->srcport) {
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/* The 'exception' bit is set, so this is a response */
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if (func & 0x80) {
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return RESPONSE_PACKET;
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}
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switch (func) {
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case READ_COILS:
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case READ_DISCRETE_INPUTS:
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/* Only possible to get a response message of 8 bytes with Discrete or Coils */
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if (len == 8) {
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/* If this is, in fact, a response then the data byte count will be 3 */
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/* This will correctly identify all messages except for those that are discrete or coil polls */
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/* where the base address range happens to have 0x03 in the upper 16-bit address register */
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if (tvb_get_guint8(tvb, 2) == 3) {
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return RESPONSE_PACKET;
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}
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else {
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return QUERY_PACKET;
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}
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}
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else {
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return RESPONSE_PACKET;
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}
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break;
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case READ_HOLDING_REGS:
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case READ_INPUT_REGS:
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case WRITE_SINGLE_COIL:
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case WRITE_SINGLE_REG:
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if (len == 8) {
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return QUERY_PACKET;
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}
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else {
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return RESPONSE_PACKET;
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}
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break;
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case WRITE_MULT_REGS:
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case WRITE_MULT_COILS:
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if (len == 8) {
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return RESPONSE_PACKET;
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}
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else {
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return QUERY_PACKET;
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}
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break;
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default:
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return CANNOT_CLASSIFY;
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break;
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}
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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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*/
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static const value_string function_code_vals[] = {
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{ READ_COILS, "Read Coils" },
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{ READ_DISCRETE_INPUTS, "Read Discrete Inputs" },
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{ READ_HOLDING_REGS, "Read Holding Registers" },
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{ READ_INPUT_REGS, "Read Input Registers" },
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{ WRITE_SINGLE_COIL, "Write Single 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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{ GET_COMM_EVENT_CTRS, "Get Comm. Event Counters" },
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{ GET_COMM_EVENT_LOG, "Get Comm. Event Log" },
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{ WRITE_MULT_COILS, "Write 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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{ READ_FILE_RECORD, "Read File Record" },
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{ WRITE_FILE_RECORD, "Write File Record" },
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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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{ ENCAP_INTERFACE_TRANSP, "Encapsulated Interface Transport" },
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{ UNITY_SCHNEIDER, "Unity (Schneider)" },
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{ 0, NULL }
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};
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/* Translate exception code to string */
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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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{ SLAVE_FAILURE, "Slave device failure" },
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{ ACKNOWLEDGE, "Acknowledge" },
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{ SLAVE_BUSY, "Slave device busy" },
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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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/* Translate Modbus Encapsulation Interface (MEI) code to string */
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static const value_string encap_interface_code_vals[] = {
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{ CANOPEN_REQ_RESP, "CANopen Request/Response " },
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{ READ_DEVICE_ID, "Read Device Identification" },
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{ 0, NULL }
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};
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/* Translate Modbus Diagnostic subfunction code to string */
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static const value_string diagnostic_code_vals[] = {
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{ RETURN_QUERY_DATA, "Return Query Data" },
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{ RESTART_COMMUNICATION_OPTION, "Restart Communications Option" },
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{ RETURN_DIAGNOSTIC_REGISTER, "Return Diagnostic Register" },
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{ CHANGE_ASCII_INPUT_DELIMITER, "Change ASCII Input Delimiter" },
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{ FORCE_LISTEN_ONLY_MODE, "Force Listen Only Mode" },
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{ CLEAR_COUNTERS_AND_DIAG_REG, "Clear Counters and Diagnostic Register" },
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{ RETURN_BUS_MESSAGE_COUNT, "Return Bus Message Count" },
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{ RETURN_BUS_COMM_ERROR_COUNT, "Return Bus Communication Error Count" },
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{ RETURN_BUS_EXCEPTION_ERROR_COUNT, "Return Bus Exception Error Count" },
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{ RETURN_SLAVE_MESSAGE_COUNT, "Return Slave Message Count" },
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{ RETURN_SLAVE_NO_RESPONSE_COUNT, "Return Slave No Response Count" },
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{ RETURN_SLAVE_NAK_COUNT, "Return Slave NAK Count" },
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{ RETURN_SLAVE_BUSY_COUNT, "Return Slave Busy Count" },
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{ RETURN_BUS_CHAR_OVERRUN_COUNT, "Return Bus Character Overrun Count" },
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{ CLEAR_OVERRUN_COUNTER_AND_FLAG, "Clear Overrun Counter and Flag" },
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{ 0, NULL }
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};
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static const value_string diagnostic_restart_communication_option_vals[] = {
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{ 0, "Leave Log" },
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{ 0xFF, "Clear Log" },
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{ 0, NULL }
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};
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/* Translate read device code to string */
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static const value_string read_device_id_vals[] = {
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{ 1, "Basic Device Identification" },
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{ 2, "Regular Device Identification" },
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{ 3, "Extended Device Identification" },
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{ 4, "Specific Identification Object" },
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{ 0, NULL }
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};
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/* Translate read device code to string */
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static const value_string object_id_vals[] = {
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{ 0, "VendorName" },
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{ 1, "ProductCode" },
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{ 2, "MajorMinorRevision" },
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{ 3, "VendorURL" },
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{ 4, "ProductName" },
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{ 5, "ModelName" },
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{ 6, "UserApplicationName" },
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{ 0, NULL }
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};
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static const value_string conformity_level_vals[] = {
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{ 0x01, "Basic Device Identification (stream)" },
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{ 0x02, "Regular Device Identification (stream)" },
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{ 0x03, "Extended Device Identification (stream)" },
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{ 0x81, "Basic Device Identification (stream and individual)" },
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{ 0x82, "Regular Device Identification (stream and individual)" },
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{ 0x83, "Extended Device Identification (stream and individual)" },
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{ 0, NULL }
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};
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static const enum_val_t mbus_register_format[] = {
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{ "UINT16 ", "UINT16 ", MODBUS_PREF_REGISTER_FORMAT_UINT16 },
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{ "INT16 ", "INT16 ", MODBUS_PREF_REGISTER_FORMAT_INT16 },
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{ "UINT32 ", "UINT32 ", MODBUS_PREF_REGISTER_FORMAT_UINT32 },
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{ "INT32 ", "INT32 ", MODBUS_PREF_REGISTER_FORMAT_INT32 },
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{ "IEEE FLT ", "IEEE FLT ", MODBUS_PREF_REGISTER_FORMAT_IEEE_FLOAT },
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{ "MODICON FLT", "MODICON FLT", MODBUS_PREF_REGISTER_FORMAT_MODICON_FLOAT },
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{ NULL, NULL, 0 }
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};
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/* Code to dissect Modbus/TCP packets */
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static int
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dissect_mbtcp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
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{
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/* Set up structures needed to add the protocol subtree and manage it */
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proto_item *mi;
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proto_tree *mbtcp_tree;
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int offset, packet_type;
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tvbuff_t *next_tvb;
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const char *func_string = "";
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const char *pkt_type_str = "";
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const char *err_str = "";
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guint16 transaction_id, protocol_id, len;
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guint8 unit_id, function_code, exception_code, subfunction_code;
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/* Make entries in Protocol column on summary display */
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "Modbus/TCP");
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col_clear(pinfo->cinfo, COL_INFO);
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transaction_id = tvb_get_ntohs(tvb, 0);
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protocol_id = tvb_get_ntohs(tvb, 2);
|
|
len = tvb_get_ntohs(tvb, 4);
|
|
|
|
unit_id = tvb_get_guint8(tvb, 6);
|
|
function_code = tvb_get_guint8(tvb, 7) & 0x7F;
|
|
|
|
offset = 0;
|
|
|
|
/* "Request" or "Response" */
|
|
packet_type = classify_mbtcp_packet(pinfo);
|
|
|
|
switch ( packet_type ) {
|
|
case QUERY_PACKET :
|
|
pkt_type_str="Query";
|
|
break;
|
|
case RESPONSE_PACKET :
|
|
pkt_type_str="Response";
|
|
break;
|
|
case CANNOT_CLASSIFY :
|
|
err_str="Unable to classify as query or response.";
|
|
pkt_type_str="unknown";
|
|
break;
|
|
default :
|
|
break;
|
|
}
|
|
|
|
/* Find exception - last bit set in function code */
|
|
if (tvb_get_guint8(tvb, 7) & 0x80) {
|
|
exception_code = tvb_get_guint8(tvb, offset + 8);
|
|
}
|
|
else {
|
|
exception_code = 0;
|
|
}
|
|
|
|
if ((function_code == ENCAP_INTERFACE_TRANSP) && (exception_code == 0)) {
|
|
func_string = val_to_str_const(tvb_get_guint8(tvb, offset + 8), encap_interface_code_vals, "Encapsulated Interface Transport");
|
|
subfunction_code = 1;
|
|
}
|
|
else if ((function_code == DIAGNOSTICS) && (exception_code == 0)) {
|
|
func_string = val_to_str_const(tvb_get_ntohs(tvb, offset + 8), diagnostic_code_vals, "Diagnostics");
|
|
subfunction_code = 1;
|
|
}
|
|
else {
|
|
func_string = val_to_str(function_code, function_code_vals, "Unknown function (%d)");
|
|
subfunction_code = 0;
|
|
}
|
|
|
|
if ( exception_code != 0 )
|
|
err_str="Exception returned ";
|
|
|
|
/* Make entries in Info column on summary display */
|
|
if (subfunction_code == 0) {
|
|
if (strlen(err_str) > 0) {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Trans: %5u; Unit: %3u, Func: %3u: %s. %s",
|
|
pkt_type_str, transaction_id, unit_id,
|
|
function_code, func_string, err_str);
|
|
}
|
|
else {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Trans: %5u; Unit: %3u, Func: %3u: %s",
|
|
pkt_type_str, transaction_id, unit_id,
|
|
function_code, func_string);
|
|
}
|
|
}
|
|
else {
|
|
if (strlen(err_str) > 0) {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Trans: %5u; Unit: %3u, Func: %3u/%3u: %s. %s",
|
|
pkt_type_str, transaction_id, unit_id,
|
|
function_code, subfunction_code, func_string, err_str);
|
|
}
|
|
else {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Trans: %5u; Unit: %3u, Func: %3u/%3u: %s",
|
|
pkt_type_str, transaction_id, unit_id,
|
|
function_code, subfunction_code, func_string);
|
|
}
|
|
}
|
|
|
|
/* Create protocol tree */
|
|
mi = proto_tree_add_protocol_format(tree, proto_mbtcp, tvb, offset,
|
|
len+6, "Modbus/TCP");
|
|
mbtcp_tree = proto_item_add_subtree(mi, ett_mbtcp);
|
|
|
|
/* Add items to protocol tree specific to Modbus/TCP */
|
|
proto_tree_add_uint(mbtcp_tree, hf_mbtcp_transid, tvb, offset, 2, transaction_id);
|
|
proto_tree_add_uint(mbtcp_tree, hf_mbtcp_protid, tvb, offset + 2, 2, protocol_id);
|
|
proto_tree_add_uint(mbtcp_tree, hf_mbtcp_len, tvb, offset + 4, 2, len);
|
|
proto_tree_add_uint(mbtcp_tree, hf_mbtcp_unitid, tvb, offset + 6, 1, unit_id);
|
|
|
|
/* dissect the Modbus PDU */
|
|
next_tvb = tvb_new_subset_length( tvb, offset+7, len-1);
|
|
|
|
/* Continue with dissection of Modbus data payload following Modbus/TCP frame */
|
|
if( tvb_reported_length_remaining(tvb, offset) > 0 )
|
|
call_dissector_with_data(modbus_handle, next_tvb, pinfo, tree, &packet_type);
|
|
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
/* Code to dissect Modbus RTU over TCP packets */
|
|
static int
|
|
dissect_mbrtu_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
|
|
{
|
|
/* Set up structures needed to add the protocol subtree and manage it */
|
|
proto_item *mi, *crc_item;
|
|
proto_tree *mbrtu_tree;
|
|
int offset, packet_type;
|
|
tvbuff_t *next_tvb;
|
|
const char *func_string = "";
|
|
const char *pkt_type_str = "";
|
|
const char *err_str = "";
|
|
guint16 len, crc16, calc_crc16;
|
|
guint8 unit_id, function_code, exception_code, subfunction_code;
|
|
|
|
/* Make entries in Protocol column on summary display */
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Modbus RTU");
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
|
|
len = tvb_reported_length(tvb);
|
|
|
|
unit_id = tvb_get_guint8(tvb, 0);
|
|
function_code = tvb_get_guint8(tvb, 1) & 0x7F;
|
|
crc16 = tvb_get_ntohs(tvb, len-2);
|
|
|
|
offset = 0;
|
|
|
|
/* "Request" or "Response" */
|
|
packet_type = classify_mbrtu_packet(pinfo, tvb);
|
|
|
|
switch ( packet_type ) {
|
|
case QUERY_PACKET :
|
|
pkt_type_str="Query";
|
|
break;
|
|
case RESPONSE_PACKET :
|
|
pkt_type_str="Response";
|
|
break;
|
|
case CANNOT_CLASSIFY :
|
|
err_str="Unable to classify as query or response.";
|
|
pkt_type_str="unknown";
|
|
break;
|
|
default :
|
|
break;
|
|
}
|
|
|
|
/* Find exception - last bit set in function code */
|
|
if (tvb_get_guint8(tvb, 1) & 0x80) {
|
|
exception_code = tvb_get_guint8(tvb, offset + 2);
|
|
}
|
|
else {
|
|
exception_code = 0;
|
|
}
|
|
|
|
if ((function_code == ENCAP_INTERFACE_TRANSP) && (exception_code == 0)) {
|
|
func_string = val_to_str_const(tvb_get_guint8(tvb, offset + 2), encap_interface_code_vals, "Encapsulated Interface Transport");
|
|
subfunction_code = 1;
|
|
}
|
|
else if ((function_code == DIAGNOSTICS) && (exception_code == 0)) {
|
|
func_string = val_to_str_const(tvb_get_ntohs(tvb, offset + 2), diagnostic_code_vals, "Diagnostics");
|
|
subfunction_code = 1;
|
|
}
|
|
else {
|
|
func_string = val_to_str(function_code, function_code_vals, "Unknown function (%d)");
|
|
subfunction_code = 0;
|
|
}
|
|
|
|
if ( exception_code != 0 )
|
|
err_str="Exception returned ";
|
|
|
|
/* Make entries in Info column on summary display */
|
|
if (subfunction_code == 0) {
|
|
if (strlen(err_str) > 0) {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Unit: %3u, Func: %3u: %s. %s",
|
|
pkt_type_str, unit_id,
|
|
function_code, func_string, err_str);
|
|
}
|
|
else {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Unit: %3u, Func: %3u: %s",
|
|
pkt_type_str, unit_id,
|
|
function_code, func_string);
|
|
}
|
|
}
|
|
else {
|
|
if (strlen(err_str) > 0) {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Unit: %3u, Func: %3u/%3u: %s. %s",
|
|
pkt_type_str, unit_id,
|
|
function_code, subfunction_code, func_string, err_str);
|
|
}
|
|
else {
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"%8s: Unit: %3u, Func: %3u/%3u: %s",
|
|
pkt_type_str, unit_id,
|
|
function_code, subfunction_code, func_string);
|
|
}
|
|
}
|
|
|
|
/* Create protocol tree */
|
|
mi = proto_tree_add_protocol_format(tree, proto_mbrtu, tvb, offset,
|
|
len, "Modbus RTU");
|
|
mbrtu_tree = proto_item_add_subtree(mi, ett_mbrtu);
|
|
|
|
/* Add items to protocol tree specific to Modbus RTU */
|
|
proto_tree_add_uint(mbrtu_tree, hf_mbrtu_unitid, tvb, offset, 1, unit_id);
|
|
crc_item = proto_tree_add_uint(mbrtu_tree, hf_mbrtu_crc16, tvb, len-2, 2, crc16);
|
|
|
|
/* CRC validation */
|
|
if (mbrtu_crc)
|
|
{
|
|
calc_crc16 = crc16_plain_tvb_offset_seed(tvb, offset, len-2, 0xFFFF);
|
|
if (g_htons(calc_crc16) != crc16)
|
|
expert_add_info_format(pinfo, crc_item, &ei_mbrtu_crc16_incorrect, "Incorrect CRC - should be 0x%04x", g_htons(calc_crc16));
|
|
}
|
|
|
|
/* when determining payload length, make sure to ignore the unit ID header & CRC-16 footer bytes */
|
|
len = len - 3;
|
|
|
|
/* dissect the Modbus PDU */
|
|
next_tvb = tvb_new_subset_length( tvb, offset+1, len);
|
|
|
|
/* Continue with dissection of Modbus data payload following Modbus RTU frame */
|
|
if( tvb_reported_length_remaining(tvb, offset) > 0 )
|
|
call_dissector_with_data(modbus_handle, next_tvb, pinfo, tree, &packet_type);
|
|
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
|
|
/* Return length of Modbus/TCP message */
|
|
static guint
|
|
get_mbtcp_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
|
|
{
|
|
guint16 plen;
|
|
|
|
/*
|
|
* Get the length of the data from the encapsulation header.
|
|
*/
|
|
plen = tvb_get_ntohs(tvb, offset + 4);
|
|
|
|
/*
|
|
* That length doesn't include the encapsulation header itself;
|
|
* add that in.
|
|
*/
|
|
return plen + 6;
|
|
}
|
|
|
|
/* Return length of Modbus RTU over TCP message */
|
|
static guint
|
|
get_mbrtu_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb,
|
|
int offset _U_, void *data _U_)
|
|
{
|
|
int packet_type;
|
|
guint8 function_code;
|
|
|
|
function_code = tvb_get_guint8(tvb, 1);
|
|
|
|
/* Modbus RTU requests do not contain a length field but they are typically a consistent size.
|
|
Responses do contain a usable 'length' byte at offset 2
|
|
XXX - Note that only some function codes are supported by this lookup function;
|
|
the rest can be added as pcap examples are made available */
|
|
|
|
/* Determine "Query" or "Response" */
|
|
packet_type = classify_mbrtu_packet(pinfo, tvb);
|
|
|
|
switch ( packet_type ) {
|
|
case QUERY_PACKET :
|
|
switch (function_code) {
|
|
case READ_COILS: /* Query messages of these types are always 8 bytes */
|
|
case READ_DISCRETE_INPUTS:
|
|
case READ_HOLDING_REGS:
|
|
case READ_INPUT_REGS:
|
|
case WRITE_SINGLE_COIL:
|
|
case WRITE_SINGLE_REG:
|
|
return 8;
|
|
break;
|
|
case WRITE_MULT_REGS:
|
|
case WRITE_MULT_COILS:
|
|
return tvb_get_guint8(tvb, 6) + 9; /* Reported size does not include 2 header, 4 FC15/16-specific, 1 size byte or 2 CRC16 bytes */
|
|
break;
|
|
default :
|
|
return tvb_captured_length(tvb); /* Fall back on tvb length */
|
|
break;
|
|
}
|
|
case RESPONSE_PACKET :
|
|
/* The 'exception' bit is set, so this is a 5-byte response */
|
|
if (function_code & 0x80) {
|
|
return 5;
|
|
}
|
|
|
|
switch (function_code) {
|
|
case READ_COILS:
|
|
case READ_DISCRETE_INPUTS:
|
|
case READ_HOLDING_REGS:
|
|
case READ_INPUT_REGS:
|
|
case WRITE_SINGLE_COIL:
|
|
case WRITE_SINGLE_REG:
|
|
return tvb_get_guint8(tvb, 2) + 5; /* Reported size does not include 2 header, 1 size byte, 2 CRC16 bytes */
|
|
break;
|
|
case WRITE_MULT_REGS: /* Response messages of FC15/16 are always 8 bytes */
|
|
case WRITE_MULT_COILS:
|
|
return 8;
|
|
break;
|
|
default :
|
|
return tvb_captured_length(tvb); /* Fall back on tvb length */
|
|
break;
|
|
}
|
|
case CANNOT_CLASSIFY :
|
|
default :
|
|
return tvb_captured_length(tvb); /* Fall back on tvb length */
|
|
break;
|
|
}
|
|
|
|
}
|
|
|
|
|
|
/* Code to dissect Modbus/TCP messages */
|
|
static int
|
|
dissect_mbtcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
|
|
{
|
|
|
|
/* Make sure there's at least enough data to determine it's a Modbus TCP packet */
|
|
if (!tvb_bytes_exist(tvb, 0, 8))
|
|
return 0;
|
|
|
|
/* check that it actually looks like Modbus/TCP */
|
|
/* protocol id == 0 */
|
|
if(tvb_get_ntohs(tvb, 2) != 0 ){
|
|
return 0;
|
|
}
|
|
/* length is at least 2 (unit_id + function_code) */
|
|
if(tvb_get_ntohs(tvb, 4) < 2 ){
|
|
return 0;
|
|
}
|
|
|
|
/* build up protocol tree and iterate over multiple packets */
|
|
tcp_dissect_pdus(tvb, pinfo, tree, mbtcp_desegment, 6,
|
|
get_mbtcp_pdu_len, dissect_mbtcp_pdu, data);
|
|
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
/* Code to dissect Modbus RTU over TCP messages */
|
|
static int
|
|
dissect_mbrtu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
|
|
{
|
|
|
|
/* Make sure there's at least enough data to determine it's a Modbus packet */
|
|
/* 5 bytes is the smallest possible valid message (exception response) */
|
|
if (!tvb_bytes_exist(tvb, 0, 5))
|
|
return 0;
|
|
|
|
/* For Modbus RTU mode, confirm that the first byte is a valid address (non-zero), */
|
|
/* so we can eliminate false-posititves on Modbus TCP messages loaded as RTU */
|
|
if(tvb_get_guint8(tvb, 0) == 0 )
|
|
return 0;
|
|
|
|
/* build up protocol tree and iterate over multiple packets */
|
|
tcp_dissect_pdus(tvb, pinfo, tree, mbrtu_desegment, 5,
|
|
get_mbrtu_pdu_len, dissect_mbrtu_pdu, data);
|
|
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
|
|
/* Code to allow further dissection of Modbus data payload */
|
|
/* Common to both Modbus/TCP and Modbus RTU dissectors */
|
|
static void
|
|
dissect_modbus_data(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint8 function_code,
|
|
gint payload_start, gint payload_len, gint register_format, guint16 reg_base)
|
|
{
|
|
gint reported_len, data_offset;
|
|
gint16 data16s;
|
|
gint32 data32s;
|
|
guint16 data16, modflt_lo, modflt_hi, reg_num=reg_base;
|
|
guint32 data32, modflt_comb;
|
|
gfloat data_float, modfloat;
|
|
proto_item *register_item = NULL;
|
|
tvbuff_t *next_tvb;
|
|
|
|
reported_len = tvb_reported_length_remaining(tvb, payload_start);
|
|
data_offset = 0;
|
|
|
|
if ( payload_start < 0 || ( payload_len + payload_start ) == 0 )
|
|
return;
|
|
|
|
/* If calculated length from remaining tvb data != bytes in packet, do not attempt to decode */
|
|
if ( payload_len != reported_len ) {
|
|
proto_tree_add_item(tree, hf_modbus_data, tvb, payload_start, reported_len, ENC_NA);
|
|
return;
|
|
}
|
|
|
|
/* If data type of payload is Holding or Input registers */
|
|
/* AND */
|
|
/* if payload length is not a multiple of 4, don't attempt to decode anything in 32-bit format */
|
|
if ((function_code == READ_HOLDING_REGS) || (function_code == READ_INPUT_REGS) || (function_code == WRITE_MULT_REGS)) {
|
|
if ((payload_len % 4 != 0) && ( (register_format == MODBUS_PREF_REGISTER_FORMAT_UINT32) ||
|
|
(register_format == MODBUS_PREF_REGISTER_FORMAT_IEEE_FLOAT) ||
|
|
(register_format == MODBUS_PREF_REGISTER_FORMAT_MODICON_FLOAT) ) ) {
|
|
register_item = proto_tree_add_item(tree, hf_modbus_data, tvb, payload_start, payload_len, ENC_NA);
|
|
expert_add_info(pinfo, register_item, &ei_modbus_data_decode);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Build a new tvb containing just the data payload */
|
|
next_tvb = tvb_new_subset(tvb, payload_start, payload_len, reported_len);
|
|
|
|
switch ( function_code ) {
|
|
|
|
case READ_HOLDING_REGS:
|
|
case READ_INPUT_REGS:
|
|
case WRITE_MULT_REGS:
|
|
while (data_offset < payload_len) {
|
|
/* Use "Preferences" options to determine decoding format of register data, as no format is implied by the protocol itself. */
|
|
/* Based on a standard register size of 16-bits, use decoding format preference to step through each register and display */
|
|
/* it in an appropriate fashion. */
|
|
switch (register_format) {
|
|
case MODBUS_PREF_REGISTER_FORMAT_UINT16: /* Standard-size unsigned integer 16-bit register */
|
|
data16 = tvb_get_ntohs(next_tvb, data_offset);
|
|
proto_tree_add_uint_format(tree, hf_modbus_reg16, next_tvb, data_offset, 2, reg_num,
|
|
"Register %u (UINT16): %u", reg_num, data16);
|
|
data_offset += 2;
|
|
reg_num += 1;
|
|
break;
|
|
case MODBUS_PREF_REGISTER_FORMAT_INT16: /* Standard-size signed integer 16-bit register */
|
|
data16s = tvb_get_ntohs(next_tvb, data_offset);
|
|
proto_tree_add_uint_format(tree, hf_modbus_reg16, next_tvb, data_offset, 2, reg_num,
|
|
"Register %u (INT16): %d", reg_num, data16s);
|
|
data_offset += 2;
|
|
reg_num += 1;
|
|
break;
|
|
case MODBUS_PREF_REGISTER_FORMAT_UINT32: /* Double-size unsigned integer 2 x 16-bit registers */
|
|
data32 = tvb_get_ntohl(next_tvb, data_offset);
|
|
proto_tree_add_uint_format(tree, hf_modbus_reg32, next_tvb, data_offset, 4, reg_num,
|
|
"Register %u (UINT32): %u", reg_num, data32);
|
|
data_offset += 4;
|
|
reg_num += 2;
|
|
break;
|
|
case MODBUS_PREF_REGISTER_FORMAT_INT32: /* Double-size signed integer 2 x 16-bit registers */
|
|
data32s = tvb_get_ntohl(next_tvb, data_offset);
|
|
proto_tree_add_uint_format(tree, hf_modbus_reg32, next_tvb, data_offset, 4, reg_num,
|
|
"Register %u (INT32): %d", reg_num, data32s);
|
|
data_offset += 4;
|
|
reg_num += 2;
|
|
break;
|
|
case MODBUS_PREF_REGISTER_FORMAT_IEEE_FLOAT: /* IEEE Floating Point, 2 x 16-bit registers */
|
|
data_float = tvb_get_ntohieee_float(next_tvb, data_offset);
|
|
|
|
proto_tree_add_uint_format(tree, hf_modbus_reg32, next_tvb, data_offset, 4, reg_num,
|
|
"Register %u (IEEE Float): %f", reg_num, data_float);
|
|
data_offset += 4;
|
|
reg_num += 2;
|
|
break;
|
|
case MODBUS_PREF_REGISTER_FORMAT_MODICON_FLOAT: /* Modicon Floating Point (word-swap), 2 x 16-bit registers */
|
|
/* Modicon-style Floating Point values are stored in reverse-word order. */
|
|
/* ie: a standard IEEE float value 59.991459 is equal to 0x426ff741 */
|
|
/* while the Modicon equivalent to this value is 0xf741426f */
|
|
/* To re-assemble a proper IEEE float, we must retrieve the 2 x 16-bit words, bit-shift the */
|
|
/* "hi" component by 16-bits and then OR them together into a combined 32-bit int. */
|
|
/* Following that operation, use some memcpy magic to copy the 4 raw data bytes from the */
|
|
/* 32-bit integer into a standard float. Not sure if there is a cleaner way possible using */
|
|
/* the Wireshark libraries, but this seems to work OK. */
|
|
|
|
modflt_lo = tvb_get_ntohs(next_tvb, data_offset);
|
|
modflt_hi = tvb_get_ntohs(next_tvb, data_offset+2);
|
|
modflt_comb = (guint32)(modflt_hi<<16) | modflt_lo;
|
|
memcpy(&modfloat, &modflt_comb, 4);
|
|
|
|
proto_tree_add_uint_format(tree, hf_modbus_reg32, next_tvb, data_offset, 4, reg_num,
|
|
"Register %u (Modicon Float): %f", reg_num, modfloat);
|
|
data_offset += 4;
|
|
reg_num += 2;
|
|
break;
|
|
default:
|
|
/* Avoid any chance of an infinite loop */
|
|
data_offset = payload_len;
|
|
break;
|
|
} /* register format switch */
|
|
|
|
} /* while loop */
|
|
|
|
break;
|
|
|
|
default:
|
|
if ( ! dissector_try_string(modbus_data_dissector_table, "data", next_tvb, pinfo, tree, NULL) )
|
|
proto_tree_add_item(tree, hf_modbus_data, tvb, payload_start, payload_len, ENC_NA);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Code to dissect Modbus request message */
|
|
static int
|
|
dissect_modbus_request(tvbuff_t *tvb, packet_info *pinfo, proto_tree *modbus_tree, guint8 function_code, gint payload_start, gint payload_len)
|
|
{
|
|
proto_tree *group_tree;
|
|
gint byte_cnt, group_offset, ii;
|
|
gint register_format = MODBUS_PREF_REGISTER_FORMAT_UINT16; /* Default value for register formatting.. */
|
|
guint8 mei_code;
|
|
guint16 reg_base=0, diagnostic_code;
|
|
guint32 group_byte_cnt, group_word_cnt;
|
|
|
|
modbus_conversation *conv;
|
|
|
|
/* See if we have any context */
|
|
conv = (modbus_conversation *)p_get_proto_data(wmem_file_scope(), pinfo, proto_modbus, 0);
|
|
|
|
if (conv) {
|
|
register_format = conv->register_format;
|
|
}
|
|
|
|
switch (function_code) {
|
|
|
|
case READ_COILS:
|
|
case READ_DISCRETE_INPUTS:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case READ_HOLDING_REGS:
|
|
case READ_INPUT_REGS:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case WRITE_SINGLE_COIL:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 2, 1, register_format, reg_base);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_padding, tvb, payload_start + 3, 1, ENC_NA);
|
|
break;
|
|
|
|
case WRITE_SINGLE_REG:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 2, 2, register_format, reg_base);
|
|
break;
|
|
|
|
case READ_EXCEPT_STAT:
|
|
/* Do Nothing */
|
|
break;
|
|
|
|
case DIAGNOSTICS:
|
|
diagnostic_code = tvb_get_ntohs(tvb, payload_start);
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_diag_sf, tvb, payload_start, 2, diagnostic_code);
|
|
switch(diagnostic_code)
|
|
{
|
|
case RETURN_QUERY_DATA:
|
|
if (payload_len > 2)
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_query_data_request, tvb, payload_start+2, payload_len-2, ENC_NA);
|
|
break;
|
|
case RESTART_COMMUNICATION_OPTION:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_restart_communication_option, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case CHANGE_ASCII_INPUT_DELIMITER:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_ascii_input_delimiter, tvb, payload_start+2, 1, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_DIAGNOSTIC_REGISTER: /* 00 00 Data Field */
|
|
case FORCE_LISTEN_ONLY_MODE: /* 00 00 Data Field */
|
|
case CLEAR_COUNTERS_AND_DIAG_REG: /* 00 00 Data Field */
|
|
case RETURN_BUS_MESSAGE_COUNT: /* 00 00 Data Field */
|
|
case RETURN_BUS_COMM_ERROR_COUNT: /* 00 00 Data Field */
|
|
case RETURN_BUS_EXCEPTION_ERROR_COUNT: /* 00 00 Data Field */
|
|
case RETURN_SLAVE_MESSAGE_COUNT: /* 00 00 Data Field */
|
|
case RETURN_SLAVE_NO_RESPONSE_COUNT: /* 00 00 Data Field */
|
|
case RETURN_SLAVE_NAK_COUNT: /* 00 00 Data Field */
|
|
case RETURN_SLAVE_BUSY_COUNT: /* 00 00 Data Field */
|
|
case RETURN_BUS_CHAR_OVERRUN_COUNT: /* 00 00 Data Field */
|
|
case CLEAR_OVERRUN_COUNTER_AND_FLAG:
|
|
default:
|
|
if (payload_len > 2)
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start+2, payload_len-2, register_format, reg_base);
|
|
break;
|
|
}
|
|
break;
|
|
case WRITE_MULT_COILS:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
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);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 5, byte_cnt, register_format, reg_base);
|
|
break;
|
|
|
|
case WRITE_MULT_REGS:
|
|
reg_base = tvb_get_ntohs(tvb, payload_start);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
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);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 5, byte_cnt, register_format, reg_base);
|
|
break;
|
|
|
|
case READ_FILE_RECORD:
|
|
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 (ii = 0; ii < byte_cnt / 7; ii++) {
|
|
group_tree = proto_tree_add_subtree_format( modbus_tree, tvb, group_offset, 7,
|
|
ett_group_hdr, NULL, "Group %u", ii);
|
|
proto_tree_add_item(group_tree, hf_modbus_reftype, tvb, group_offset, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(group_tree, hf_modbus_lreference, tvb, group_offset + 1, 4, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(group_tree, hf_modbus_wordcnt, tvb, group_offset + 5, 2, ENC_BIG_ENDIAN);
|
|
group_offset += 7;
|
|
}
|
|
break;
|
|
|
|
case WRITE_FILE_RECORD:
|
|
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;
|
|
ii = 0;
|
|
while (byte_cnt > 0) {
|
|
group_word_cnt = tvb_get_ntohs(tvb, group_offset + 5);
|
|
group_byte_cnt = (2 * group_word_cnt) + 7;
|
|
group_tree = proto_tree_add_subtree_format( modbus_tree, tvb, group_offset,
|
|
group_byte_cnt, ett_group_hdr, NULL, "Group %u", ii);
|
|
proto_tree_add_item(group_tree, hf_modbus_reftype, tvb, group_offset, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(group_tree, hf_modbus_lreference, tvb, group_offset + 1, 4, ENC_BIG_ENDIAN);
|
|
proto_tree_add_uint(group_tree, hf_modbus_wordcnt, tvb, group_offset + 5, 2, group_word_cnt);
|
|
dissect_modbus_data(tvb, pinfo, group_tree, function_code, group_offset + 7, group_byte_cnt - 7, register_format, reg_base);
|
|
group_offset += group_byte_cnt;
|
|
byte_cnt -= group_byte_cnt;
|
|
ii++;
|
|
}
|
|
break;
|
|
|
|
case MASK_WRITE_REG:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_andmask, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_ormask, tvb, payload_start + 4, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case READ_WRITE_REG:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_readref, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_readwordcnt, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_writeref, tvb, payload_start + 4, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_writewordcnt, tvb, payload_start + 6, 2, ENC_BIG_ENDIAN);
|
|
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);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 9, byte_cnt, register_format, reg_base);
|
|
break;
|
|
|
|
case READ_FIFO_QUEUE:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case ENCAP_INTERFACE_TRANSP:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_mei, tvb, payload_start, 1, ENC_BIG_ENDIAN);
|
|
mei_code = tvb_get_guint8(tvb, payload_start);
|
|
switch (mei_code)
|
|
{
|
|
case READ_DEVICE_ID:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_read_device_id, tvb, payload_start+1, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_object_id, tvb, payload_start+2, 1, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case CANOPEN_REQ_RESP:
|
|
/* CANopen protocol not part of the Modbus/TCP specification */
|
|
default:
|
|
if (payload_len > 1)
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start, payload_len-1, register_format, reg_base);
|
|
break;
|
|
}
|
|
|
|
break;
|
|
|
|
case REPORT_SLAVE_ID:
|
|
default:
|
|
if (payload_len > 0)
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start, payload_len, register_format, reg_base);
|
|
break;
|
|
|
|
} /* Function Code */
|
|
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
/* Code to dissect Modbus Response message */
|
|
static int
|
|
dissect_modbus_response(tvbuff_t *tvb, packet_info *pinfo, proto_tree *modbus_tree, guint8 function_code, gint payload_start, gint payload_len)
|
|
{
|
|
|
|
proto_tree *group_tree, *event_tree, *event_item_tree, *device_objects_tree, *device_objects_item_tree;
|
|
proto_item *mei;
|
|
gint byte_cnt, group_offset, event_index, object_index, object_len, num_objects, ii;
|
|
gint register_format = MODBUS_PREF_REGISTER_FORMAT_UINT16; /* Default value for register formatting.. */
|
|
guint8 object_type, mei_code, event_code;
|
|
guint16 reg_base=0, diagnostic_code;
|
|
guint32 group_byte_cnt, group_word_cnt;
|
|
|
|
/* Conversation tracking */
|
|
proto_item *request_frame_item;
|
|
modbus_conversation *conv;
|
|
guint8 req_function_code;
|
|
guint32 req_frame_num;
|
|
gboolean request_found = FALSE;
|
|
modbus_request_info_t *request_data;
|
|
|
|
/* See if we have any context */
|
|
conv = (modbus_conversation *)p_get_proto_data(wmem_file_scope(), pinfo, proto_modbus, 0);
|
|
|
|
if (conv) {
|
|
|
|
wmem_list_frame_t *frame = wmem_list_head(conv->modbus_request_frame_data);
|
|
/* Step backward through all logged instances of request frames, looking for a request frame number that
|
|
occurred immediately prior to current frame number that has a matching function code */
|
|
while (frame && !request_found) {
|
|
request_data = (modbus_request_info_t *)wmem_list_frame_data(frame);
|
|
req_frame_num = request_data->fnum;
|
|
req_function_code = request_data->function_code;
|
|
if ((pinfo->num > req_frame_num) && (req_function_code == function_code)) {
|
|
request_frame_item = proto_tree_add_uint(modbus_tree, hf_modbus_request_frame, tvb, 0, 0, req_frame_num);
|
|
reg_base = request_data->base_address;
|
|
PROTO_ITEM_SET_GENERATED(request_frame_item);
|
|
request_found = TRUE;
|
|
}
|
|
frame = wmem_list_frame_next(frame);
|
|
}
|
|
|
|
register_format = conv->register_format;
|
|
} /* conv */
|
|
|
|
switch (function_code) {
|
|
|
|
case READ_COILS:
|
|
case READ_DISCRETE_INPUTS:
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1, byte_cnt);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 1, byte_cnt, register_format, reg_base);
|
|
break;
|
|
|
|
case READ_HOLDING_REGS:
|
|
case READ_INPUT_REGS:
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1, byte_cnt);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 1, byte_cnt, register_format, reg_base);
|
|
break;
|
|
|
|
case WRITE_SINGLE_COIL:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 2, 1, register_format, reg_base);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_padding, tvb, payload_start + 3, 1, ENC_NA);
|
|
break;
|
|
|
|
case WRITE_SINGLE_REG:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 2, 2, register_format, reg_base);
|
|
break;
|
|
|
|
case READ_EXCEPT_STAT:
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start, 1, register_format, reg_base);
|
|
break;
|
|
|
|
case DIAGNOSTICS:
|
|
diagnostic_code = tvb_get_ntohs(tvb, payload_start);
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_diag_sf, tvb, payload_start, 2, diagnostic_code);
|
|
switch(diagnostic_code)
|
|
{
|
|
case RETURN_QUERY_DATA: /* Echo of Request */
|
|
if (payload_len > 2)
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_query_data_echo, tvb, payload_start+2, payload_len-2, ENC_NA);
|
|
break;
|
|
case RESTART_COMMUNICATION_OPTION: /* Echo of Request */
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_restart_communication_option, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_DIAGNOSTIC_REGISTER:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_diag_register, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case CHANGE_ASCII_INPUT_DELIMITER: /* XXX - Do we expect this to ever be a response? */
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_ascii_input_delimiter, tvb, payload_start+2, 1, ENC_BIG_ENDIAN);
|
|
break;
|
|
case CLEAR_COUNTERS_AND_DIAG_REG: /* Echo of Request */
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_clear_ctr_diag_reg, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_BUS_MESSAGE_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_bus_message_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_BUS_COMM_ERROR_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_bus_comm_error_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_BUS_EXCEPTION_ERROR_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_bus_exception_error_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_SLAVE_MESSAGE_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_slave_message_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_SLAVE_NO_RESPONSE_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_no_slave_response_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_SLAVE_NAK_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_slave_nak_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_SLAVE_BUSY_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_slave_busy_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case RETURN_BUS_CHAR_OVERRUN_COUNT:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_diag_return_bus_char_overrun_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
case CLEAR_OVERRUN_COUNTER_AND_FLAG: /* Echo of Request */
|
|
case FORCE_LISTEN_ONLY_MODE: /* No response anticipated */
|
|
default:
|
|
if (payload_len > 2)
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start+2, payload_len-2, register_format, reg_base);
|
|
break;
|
|
} /* diagnostic_code */
|
|
break;
|
|
|
|
case GET_COMM_EVENT_CTRS:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_status, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_event_count, tvb, payload_start+2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case GET_COMM_EVENT_LOG:
|
|
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_item(modbus_tree, hf_modbus_status, tvb, payload_start+1, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_event_count, tvb, payload_start+3, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_message_count, tvb, payload_start+5, 2, ENC_BIG_ENDIAN);
|
|
if (byte_cnt-6 > 0) {
|
|
byte_cnt -= 6;
|
|
event_index = 0;
|
|
event_tree = proto_tree_add_subtree(modbus_tree, tvb, payload_start+7, byte_cnt, ett_events, NULL, "Events");
|
|
while (byte_cnt > 0) {
|
|
event_code = tvb_get_guint8(tvb, payload_start+7+event_index);
|
|
if (event_code == 0) {
|
|
proto_tree_add_uint_format(event_tree, hf_modbus_event, tvb, payload_start+7+event_index, 1, event_code, "Initiated Communication Restart");
|
|
}
|
|
else if (event_code == 4) {
|
|
proto_tree_add_uint_format(event_tree, hf_modbus_event, tvb, payload_start+7+event_index, 1, event_code, "Entered Listen Only Mode");
|
|
}
|
|
else if (event_code & REMOTE_DEVICE_RECV_EVENT_MASK) {
|
|
mei = proto_tree_add_uint_format(event_tree, hf_modbus_event, tvb, payload_start+7+event_index, 1,
|
|
event_code, "Receive Event: 0x%02X", event_code);
|
|
event_item_tree = proto_item_add_subtree(mei, ett_events_recv);
|
|
|
|
/* add subtrees to describe each event bit */
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_recv_comm_err,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_recv_char_over,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_recv_lo_mode,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_recv_broadcast,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
}
|
|
else if ((event_code & REMOTE_DEVICE_SEND_EVENT_MASK) == REMOTE_DEVICE_SEND_EVENT_VALUE) {
|
|
mei = proto_tree_add_uint_format(event_tree, hf_modbus_event, tvb, payload_start+7+event_index, 1,
|
|
event_code, "Send Event: 0x%02X", event_code);
|
|
event_item_tree = proto_item_add_subtree(mei, ett_events_send);
|
|
|
|
/* add subtrees to describe each event bit */
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_send_read_ex,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_send_slave_abort_ex,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_send_slave_busy_ex,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_send_slave_nak_ex,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_send_write_timeout,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
proto_tree_add_item(event_item_tree, hf_modbus_event_send_lo_mode,
|
|
tvb, payload_start+7+event_index, 1, ENC_LITTLE_ENDIAN );
|
|
}
|
|
else {
|
|
proto_tree_add_uint_format(event_tree, hf_modbus_event, tvb, payload_start+7+event_index, 1, event_code, "Unknown Event");
|
|
}
|
|
|
|
byte_cnt--;
|
|
event_index++;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case WRITE_MULT_COILS:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_bitcnt, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case WRITE_MULT_REGS:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_wordcnt, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case READ_FILE_RECORD:
|
|
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;
|
|
ii = 0;
|
|
while (byte_cnt > 0) {
|
|
group_byte_cnt = (guint32)tvb_get_guint8(tvb, group_offset);
|
|
group_tree = proto_tree_add_subtree_format( modbus_tree, tvb, group_offset, group_byte_cnt + 1,
|
|
ett_group_hdr, NULL, "Group %u", ii);
|
|
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, ENC_BIG_ENDIAN);
|
|
dissect_modbus_data(tvb, pinfo, group_tree, function_code, group_offset + 2, group_byte_cnt - 1, register_format, reg_base);
|
|
group_offset += (group_byte_cnt + 1);
|
|
byte_cnt -= (group_byte_cnt + 1);
|
|
ii++;
|
|
}
|
|
break;
|
|
|
|
case WRITE_FILE_RECORD: /* Normal response is echo of request */
|
|
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;
|
|
ii = 0;
|
|
while (byte_cnt > 0) {
|
|
group_word_cnt = tvb_get_ntohs(tvb, group_offset + 5);
|
|
group_byte_cnt = (2 * group_word_cnt) + 7;
|
|
group_tree = proto_tree_add_subtree_format( modbus_tree, tvb, group_offset,
|
|
group_byte_cnt, ett_group_hdr, NULL, "Group %u", ii);
|
|
proto_tree_add_item(group_tree, hf_modbus_reftype, tvb, group_offset, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(group_tree, hf_modbus_lreference, tvb, group_offset + 1, 4, ENC_BIG_ENDIAN);
|
|
proto_tree_add_uint(group_tree, hf_modbus_wordcnt, tvb, group_offset + 5, 2, group_word_cnt);
|
|
dissect_modbus_data(tvb, pinfo, group_tree, function_code, group_offset + 7, group_byte_cnt - 7, register_format, reg_base);
|
|
group_offset += group_byte_cnt;
|
|
byte_cnt -= group_byte_cnt;
|
|
ii++;
|
|
}
|
|
break;
|
|
|
|
case MASK_WRITE_REG: /* Normal response is echo of request */
|
|
proto_tree_add_item(modbus_tree, hf_modbus_reference, tvb, payload_start, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_andmask, tvb, payload_start + 2, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_ormask, tvb, payload_start + 4, 2, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
case READ_WRITE_REG:
|
|
byte_cnt = (guint32)tvb_get_guint8(tvb, payload_start);
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_bytecnt, tvb, payload_start, 1, byte_cnt);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 1, byte_cnt, register_format, reg_base);
|
|
break;
|
|
|
|
case READ_FIFO_QUEUE:
|
|
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, ENC_BIG_ENDIAN);
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start + 4, byte_cnt - 2, register_format, reg_base);
|
|
break;
|
|
|
|
case ENCAP_INTERFACE_TRANSP:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_mei, tvb, payload_start, 1, ENC_BIG_ENDIAN);
|
|
mei_code = tvb_get_guint8(tvb, payload_start);
|
|
switch (mei_code)
|
|
{
|
|
case READ_DEVICE_ID:
|
|
proto_tree_add_item(modbus_tree, hf_modbus_read_device_id, tvb, payload_start+1, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_conformity_level, tvb, payload_start+2, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_more_follows, tvb, payload_start+3, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(modbus_tree, hf_modbus_next_object_id, tvb, payload_start+4, 1, ENC_BIG_ENDIAN);
|
|
num_objects = tvb_get_guint8(tvb, payload_start+5);
|
|
proto_tree_add_uint(modbus_tree, hf_modbus_num_objects, tvb, payload_start+5, 1, num_objects);
|
|
device_objects_tree = proto_tree_add_subtree(modbus_tree, tvb, payload_start+6, payload_len-6,
|
|
ett_device_id_objects, NULL, "Objects");
|
|
|
|
object_index = 0;
|
|
for (ii = 0; ii < num_objects; ii++)
|
|
{
|
|
/* add each "object item" as its own subtree */
|
|
|
|
/* compute length of object */
|
|
object_type = tvb_get_guint8(tvb, payload_start+6+object_index);
|
|
object_len = tvb_get_guint8(tvb, payload_start+6+object_index+1);
|
|
|
|
device_objects_item_tree = proto_tree_add_subtree_format(device_objects_tree, tvb, payload_start+6+object_index, 2+object_len,
|
|
ett_device_id_object_items, NULL, "Object #%d", ii+1);
|
|
|
|
proto_tree_add_item(device_objects_item_tree, hf_modbus_object_id, tvb, payload_start+6+object_index, 1, ENC_BIG_ENDIAN);
|
|
object_index++;
|
|
|
|
proto_tree_add_uint(device_objects_item_tree, hf_modbus_list_object_len, tvb, payload_start+6+object_index, 1, object_len);
|
|
object_index++;
|
|
|
|
if (object_type < 7)
|
|
{
|
|
proto_tree_add_item(device_objects_item_tree, hf_modbus_object_str_value, tvb, payload_start+6+object_index, object_len, ENC_ASCII|ENC_NA);
|
|
}
|
|
else
|
|
{
|
|
if (object_len > 0)
|
|
proto_tree_add_item(device_objects_item_tree, hf_modbus_object_value, tvb, payload_start+6+object_index, object_len, ENC_NA);
|
|
}
|
|
object_index += object_len;
|
|
} /* for ii */
|
|
break;
|
|
|
|
case CANOPEN_REQ_RESP:
|
|
/* CANopen protocol not part of the Modbus/TCP specification */
|
|
default:
|
|
if (payload_len > 1)
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start, payload_len-1, register_format, reg_base);
|
|
break;
|
|
} /* mei_code */
|
|
break;
|
|
|
|
case REPORT_SLAVE_ID:
|
|
default:
|
|
if (payload_len > 0)
|
|
dissect_modbus_data(tvb, pinfo, modbus_tree, function_code, payload_start, payload_len, register_format, reg_base);
|
|
break;
|
|
|
|
} /* function code */
|
|
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
|
|
/* Dissect the Modbus Payload. Called from either Modbus/TCP or Modbus RTU Dissector */
|
|
static int
|
|
dissect_modbus(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
|
|
{
|
|
proto_tree *modbus_tree;
|
|
proto_item *mi;
|
|
int offset = 0;
|
|
int* packet_type = (int*)data;
|
|
gint payload_start, payload_len, len;
|
|
guint8 function_code, exception_code;
|
|
|
|
/* Reject the packet if data passed from the mbrtu or mbtcp dissector is NULL */
|
|
if (packet_type == NULL)
|
|
return 0;
|
|
|
|
len = tvb_captured_length(tvb);
|
|
|
|
/* If the packet is zero-length, we should not attempt to dissect any further */
|
|
if (len == 0)
|
|
return 0;
|
|
|
|
/* Add items to protocol tree specific to Modbus */
|
|
mi = proto_tree_add_protocol_format(tree, proto_modbus, tvb, offset, len, "Modbus");
|
|
modbus_tree = proto_item_add_subtree(mi, ett_modbus_hdr);
|
|
|
|
function_code = tvb_get_guint8(tvb, offset) & 0x7F;
|
|
proto_tree_add_item(modbus_tree, hf_modbus_functioncode, tvb, offset, 1, ENC_BIG_ENDIAN);
|
|
|
|
/* Conversation support */
|
|
if (!pinfo->fd->flags.visited) {
|
|
conversation_t *conversation = NULL;
|
|
modbus_conversation *modbus_conv_data = NULL;
|
|
|
|
/* Find a conversation, create a new if no one exists */
|
|
conversation = find_or_create_conversation(pinfo);
|
|
modbus_conv_data = (modbus_conversation *)conversation_get_proto_data(conversation, proto_modbus);
|
|
|
|
if (modbus_conv_data == NULL){
|
|
modbus_conv_data = wmem_new(wmem_file_scope(), modbus_conversation);
|
|
modbus_conv_data->modbus_request_frame_data = wmem_list_new(wmem_file_scope());
|
|
modbus_conv_data->register_format = global_mbus_register_format;
|
|
conversation_add_proto_data(conversation, proto_modbus, (void *)modbus_conv_data);
|
|
}
|
|
|
|
p_add_proto_data(wmem_file_scope(), pinfo, proto_modbus, 0, modbus_conv_data);
|
|
|
|
if (*packet_type == QUERY_PACKET) {
|
|
/*create the modbus_request frame. It holds the request information.*/
|
|
modbus_request_info_t *frame_ptr = wmem_new(wmem_file_scope(), modbus_request_info_t);
|
|
|
|
/* load information into the modbus request frame */
|
|
frame_ptr->fnum = pinfo->num;
|
|
frame_ptr->function_code = function_code;
|
|
frame_ptr->base_address = tvb_get_ntohs(tvb, 1);
|
|
frame_ptr->num_reg = tvb_get_ntohs(tvb, 3);
|
|
|
|
wmem_list_prepend(modbus_conv_data->modbus_request_frame_data, frame_ptr);
|
|
}
|
|
|
|
} /* !visited */
|
|
|
|
/* Find exception - last bit set in function code */
|
|
if (tvb_get_guint8(tvb, offset) & 0x80 ) {
|
|
exception_code = tvb_get_guint8(tvb, offset+1);
|
|
}
|
|
else {
|
|
exception_code = 0;
|
|
}
|
|
|
|
payload_start = offset + 1;
|
|
payload_len = len - 1;
|
|
|
|
if (exception_code != 0) {
|
|
proto_item_set_text(mi, "Function %u: %s. Exception: %s",
|
|
function_code,
|
|
val_to_str_const(function_code, function_code_vals, "Unknown Function"),
|
|
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 {
|
|
|
|
/* Follow different dissection path depending on whether packet is query or response */
|
|
if (*packet_type == QUERY_PACKET) {
|
|
dissect_modbus_request(tvb, pinfo, modbus_tree, function_code, payload_start, payload_len);
|
|
}
|
|
else if (*packet_type == RESPONSE_PACKET) {
|
|
dissect_modbus_response(tvb, pinfo, modbus_tree, function_code, payload_start, payload_len);
|
|
}
|
|
|
|
}
|
|
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
/* Register the protocol with Wireshark */
|
|
void
|
|
proto_register_modbus(void)
|
|
{
|
|
/* Modbus/TCP header fields */
|
|
static hf_register_info mbtcp_hf[] = {
|
|
{ &hf_mbtcp_transid,
|
|
{ "Transaction Identifier", "mbtcp.trans_id",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_mbtcp_protid,
|
|
{ "Protocol Identifier", "mbtcp.prot_id",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_mbtcp_len,
|
|
{ "Length", "mbtcp.len",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_mbtcp_unitid,
|
|
{ "Unit Identifier", "mbtcp.unit_id",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
};
|
|
|
|
/* Modbus RTU header fields */
|
|
static hf_register_info mbrtu_hf[] = {
|
|
{ &hf_mbrtu_unitid,
|
|
{ "Unit ID", "mbrtu.unit_id",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_mbrtu_crc16,
|
|
{ "CRC-16", "mbrtu.crc16",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
};
|
|
|
|
static ei_register_info mbrtu_ei[] = {
|
|
{ &ei_mbrtu_crc16_incorrect,
|
|
{ "mbrtu.crc16.incorrect", PI_CHECKSUM, PI_WARN,
|
|
"Incorrect CRC", EXPFILL }
|
|
},
|
|
};
|
|
|
|
/* Modbus header fields */
|
|
static hf_register_info hf[] = {
|
|
{ &hf_modbus_request_frame,
|
|
{ "Request Frame", "modbus.request_frame",
|
|
FT_FRAMENUM, BASE_NONE,
|
|
NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_functioncode,
|
|
{ "Function Code", "modbus.func_code",
|
|
FT_UINT8, BASE_DEC, VALS(function_code_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_reference,
|
|
{ "Reference Number", "modbus.reference_num",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_padding,
|
|
{ "Padding", "modbus.padding",
|
|
FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_lreference,
|
|
{ "Reference Number (32 bit)", "modbus.reference_num_32",
|
|
FT_UINT32, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_reftype,
|
|
{ "Reference Type", "modbus.reference_type",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_readref,
|
|
{ "Read Reference Number", "modbus.read_reference_num",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_writeref,
|
|
{ "Write Reference Number", "modbus.write_reference_num",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_wordcnt,
|
|
{ "Word Count", "modbus.word_cnt",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_readwordcnt,
|
|
{ "Read Word Count", "modbus.read_word_cnt",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_writewordcnt,
|
|
{ "Write Word Count", "modbus.write_word_cnt",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_bitcnt,
|
|
{ "Bit Count", "modbus.bit_cnt",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_bytecnt,
|
|
{ "Byte Count", "modbus.byte_cnt",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_lbytecnt,
|
|
{ "Byte Count (16-bit)", "modbus.byte_cnt_16",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_exceptioncode,
|
|
{ "Exception Code", "modbus.exception_code",
|
|
FT_UINT8, BASE_DEC, VALS(exception_code_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_sf,
|
|
{ "Diagnostic Code", "modbus.diagnostic_code",
|
|
FT_UINT16, BASE_DEC, VALS(diagnostic_code_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_query_data_request,
|
|
{ "Request Data", "modbus.diagnostic.return_query_data.request",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_query_data_echo,
|
|
{ "Echo Data", "modbus.diagnostic.return_query_data.echo",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_restart_communication_option,
|
|
{ "Restart Communication Option", "modbus.diagnostic.restart_communication_option",
|
|
FT_UINT16, BASE_HEX, VALS(diagnostic_restart_communication_option_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_diag_register,
|
|
{ "Diagnostic Register Contents", "modbus.diagnostic.return_diag_register",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_ascii_input_delimiter,
|
|
{ "CHAR", "modbus.diagnostic.ascii_input_delimiter",
|
|
FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_clear_ctr_diag_reg,
|
|
{ "Clear Counters & Diag Register Echo", "modbus.diagnostic.clear_ctr_diag_reg",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_bus_message_count,
|
|
{ "Total Message Count", "modbus.diagnostic.bus_message_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_bus_comm_error_count,
|
|
{ "CRC Error Count", "modbus.diagnostic.bus_comm_error_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_bus_exception_error_count,
|
|
{ "Exception Error Count", "modbus.diagnostic.bus_exception_error_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_slave_message_count,
|
|
{ "Slave Message Count", "modbus.diagnostic.slave_message_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_no_slave_response_count,
|
|
{ "Slave No Response Count", "modbus.diagnostic.no_slave_response_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_slave_nak_count,
|
|
{ "Slave NAK Count", "modbus.diagnostic.slave_nak_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_slave_busy_count,
|
|
{ "Slave Device Busy Count", "modbus.diagnostic.slave_busy_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_diag_return_bus_char_overrun_count,
|
|
{ "Slave Character Overrun Count", "modbus.diagnostic.bus_char_overrun_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_status,
|
|
{ "Status", "modbus.ev_status",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event,
|
|
{ "Event", "modbus.event",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_count,
|
|
{ "Event Count", "modbus.ev_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_message_count,
|
|
{ "Message Count", "modbus.ev_msg_count",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_recv_comm_err,
|
|
{ "Communication Error", "modbus.ev_recv_comm_err",
|
|
FT_UINT8, BASE_DEC, NULL, 0x02,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_recv_char_over,
|
|
{ "Character Overrun", "modbus.ev_recv_char_over",
|
|
FT_UINT8, BASE_DEC, NULL, 0x10,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_recv_lo_mode,
|
|
{ "Currently in Listen Only Mode", "modbus.ev_recv_lo_mode",
|
|
FT_UINT8, BASE_DEC, NULL, 0x20,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_recv_broadcast,
|
|
{ "Broadcast Received", "modbus.ev_recv_broadcast",
|
|
FT_UINT8, BASE_DEC, NULL, 0x40,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_send_read_ex,
|
|
{ "Read Exception Sent", "modbus.ev_send_read_ex",
|
|
FT_UINT8, BASE_DEC, NULL, 0x01,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_send_slave_abort_ex,
|
|
{ "Slave Abort Exception Sent", "modbus.ev_send_slave_abort_ex",
|
|
FT_UINT8, BASE_DEC, NULL, 0x02,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_send_slave_busy_ex,
|
|
{ "Slave Busy Exception Sent", "modbus.ev_send_slave_busy_ex",
|
|
FT_UINT8, BASE_DEC, NULL, 0x04,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_send_slave_nak_ex,
|
|
{ "Slave Program NAK Exception Sent", "modbus.ev_send_slave_nak_ex",
|
|
FT_UINT8, BASE_DEC, NULL, 0x08,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_send_write_timeout,
|
|
{ "Write Timeout Error Occurred", "modbus.ev_send_write_timeout",
|
|
FT_UINT8, BASE_DEC, NULL, 0x10,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_event_send_lo_mode,
|
|
{ "Currently in Listen Only Mode", "modbus.ev_send_lo_mode",
|
|
FT_UINT8, BASE_DEC, NULL, 0x20,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_andmask,
|
|
{ "AND mask", "modbus.and_mask",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_ormask,
|
|
{ "OR mask", "modbus.or_mask",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_data,
|
|
{ "Data", "modbus.data",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_mei,
|
|
{ "MEI type", "modbus.mei",
|
|
FT_UINT8, BASE_DEC, VALS(encap_interface_code_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_read_device_id,
|
|
{ "Read Device ID", "modbus.read_device_id",
|
|
FT_UINT8, BASE_DEC, VALS(read_device_id_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_object_id,
|
|
{ "Object ID", "modbus.object_id",
|
|
FT_UINT8, BASE_DEC, VALS(object_id_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_num_objects,
|
|
{ "Number of Objects", "modbus.num_objects",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_list_object_len,
|
|
{ "Object length", "modbus.objects_len",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_conformity_level,
|
|
{ "Conformity Level", "modbus.conformity_level",
|
|
FT_UINT8, BASE_HEX, VALS(conformity_level_vals), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_more_follows,
|
|
{ "More Follows", "modbus.more_follows",
|
|
FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_next_object_id,
|
|
{ "Next Object ID", "modbus.next_object_id",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_object_str_value,
|
|
{ "Object String Value", "modbus.object_str_value",
|
|
FT_STRING, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_object_value,
|
|
{ "Object Value", "modbus.object_value",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_reg16,
|
|
{ "Register Value (16-bit)", "modbus.reg16",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_modbus_reg32,
|
|
{ "Register Value (32-bit)", "modbus.reg32",
|
|
FT_UINT32, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
};
|
|
|
|
/* Setup protocol subtree array */
|
|
static gint *ett[] = {
|
|
&ett_mbtcp,
|
|
&ett_mbrtu,
|
|
&ett_modbus_hdr,
|
|
&ett_group_hdr,
|
|
&ett_events,
|
|
&ett_events_recv,
|
|
&ett_events_send,
|
|
&ett_device_id_objects,
|
|
&ett_device_id_object_items
|
|
};
|
|
|
|
static ei_register_info ei[] = {
|
|
{ &ei_modbus_data_decode,
|
|
{ "modbus.data.decode", PI_PROTOCOL, PI_WARN,
|
|
"Invalid decoding options, register data not a multiple of 4!", EXPFILL }
|
|
},
|
|
};
|
|
module_t *mbtcp_module;
|
|
module_t *mbrtu_module;
|
|
module_t *modbus_module;
|
|
expert_module_t* expert_mbrtu;
|
|
expert_module_t* expert_modbus;
|
|
|
|
/* Register the protocol name and description */
|
|
proto_mbtcp = proto_register_protocol("Modbus/TCP", "Modbus/TCP", "mbtcp");
|
|
proto_mbrtu = proto_register_protocol("Modbus RTU", "Modbus RTU", "mbrtu");
|
|
proto_modbus = proto_register_protocol("Modbus", "Modbus", "modbus");
|
|
|
|
/* Registering protocol to be called by another dissector */
|
|
modbus_handle = register_dissector("modbus", dissect_modbus, proto_modbus);
|
|
mbtcp_handle = register_dissector("mbtcp", dissect_mbtcp, proto_mbtcp);
|
|
mbrtu_handle = register_dissector("mbrtu", dissect_mbrtu, proto_mbrtu);
|
|
|
|
/* Registering subdissectors table */
|
|
modbus_data_dissector_table = register_dissector_table("modbus.data", "Modbus Data", FT_STRING, BASE_NONE, DISSECTOR_TABLE_NOT_ALLOW_DUPLICATE);
|
|
modbus_dissector_table = register_dissector_table("mbtcp.prot_id", "Modbus/TCP protocol identifier", FT_UINT16, BASE_DEC, DISSECTOR_TABLE_NOT_ALLOW_DUPLICATE);
|
|
|
|
/* Required function calls to register the header fields and subtrees used */
|
|
proto_register_field_array(proto_mbtcp, mbtcp_hf, array_length(mbtcp_hf));
|
|
proto_register_field_array(proto_mbrtu, mbrtu_hf, array_length(mbrtu_hf));
|
|
proto_register_field_array(proto_modbus, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
expert_mbrtu = expert_register_protocol(proto_mbrtu);
|
|
expert_register_field_array(expert_mbrtu, mbrtu_ei, array_length(mbrtu_ei));
|
|
expert_modbus = expert_register_protocol(proto_modbus);
|
|
expert_register_field_array(expert_modbus, ei, array_length(ei));
|
|
|
|
|
|
/* Register required preferences for Modbus Protocol variants */
|
|
mbtcp_module = prefs_register_protocol(proto_mbtcp, proto_reg_handoff_mbtcp);
|
|
mbrtu_module = prefs_register_protocol(proto_mbrtu, proto_reg_handoff_mbrtu);
|
|
modbus_module = prefs_register_protocol(proto_modbus, NULL);
|
|
|
|
/* Modbus RTU Preference - Desegment, defaults to TRUE for TCP desegmentation */
|
|
prefs_register_bool_preference(mbtcp_module, "desegment",
|
|
"Desegment all Modbus RTU packets spanning multiple TCP segments",
|
|
"Whether the Modbus RTU dissector should desegment all messages spanning multiple TCP segments",
|
|
&mbtcp_desegment);
|
|
|
|
/* Modbus/TCP Preference - Default TCP Port, allows for "user" port either than 502. */
|
|
prefs_register_uint_preference(mbtcp_module, "tcp.port", "Modbus/TCP Port",
|
|
"Set the TCP port for Modbus/TCP packets (if other"
|
|
" than the default of 502)",
|
|
10, &global_mbus_tcp_port);
|
|
|
|
/* Modbus RTU Preference - Desegment, defaults to TRUE for TCP desegmentation */
|
|
prefs_register_bool_preference(mbrtu_module, "desegment",
|
|
"Desegment all Modbus RTU packets spanning multiple TCP segments",
|
|
"Whether the Modbus RTU dissector should desegment all messages spanning multiple TCP segments",
|
|
&mbrtu_desegment);
|
|
|
|
/* Modbus RTU Preference - CRC verification, defaults to FALSE (no verification)*/
|
|
prefs_register_bool_preference(mbrtu_module, "crc_verification",
|
|
"Validate CRC",
|
|
"Whether to validate the CRC",
|
|
&mbrtu_crc);
|
|
|
|
/* Modbus RTU Preference - Default TCP Port, defaults to zero, allows custom user port. */
|
|
prefs_register_uint_preference(mbrtu_module, "tcp.port", "Modbus RTU Port",
|
|
"Set the TCP port for encapsulated Modbus RTU packets",
|
|
10, &global_mbus_rtu_port);
|
|
|
|
/* Modbus Preference - Holding/Input Register format, this allows for deeper dissection of response data */
|
|
prefs_register_enum_preference(modbus_module, "mbus_register_format",
|
|
"Holding/Input Register Format",
|
|
"Register Format",
|
|
&global_mbus_register_format,
|
|
mbus_register_format,
|
|
TRUE);
|
|
|
|
/* Obsolete Preferences */
|
|
prefs_register_obsolete_preference(mbtcp_module, "mbus_register_addr_type");
|
|
prefs_register_obsolete_preference(mbtcp_module, "mbus_register_format");
|
|
prefs_register_obsolete_preference(mbrtu_module, "mbus_register_addr_type");
|
|
prefs_register_obsolete_preference(mbrtu_module, "mbus_register_format");
|
|
|
|
}
|
|
|
|
|
|
/* 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)
|
|
{
|
|
static unsigned int mbtcp_port;
|
|
|
|
/* Make sure to use Modbus/TCP Preferences field to determine default TCP port */
|
|
|
|
if(mbtcp_port != 0 && mbtcp_port != global_mbus_tcp_port){
|
|
dissector_delete_uint("tcp.port", mbtcp_port, mbtcp_handle);
|
|
}
|
|
|
|
if(global_mbus_tcp_port != 0 && mbtcp_port != global_mbus_tcp_port) {
|
|
dissector_add_uint("tcp.port", global_mbus_tcp_port, mbtcp_handle);
|
|
}
|
|
|
|
mbtcp_port = global_mbus_tcp_port;
|
|
|
|
dissector_add_uint("mbtcp.prot_id", MODBUS_PROTOCOL_ID, modbus_handle);
|
|
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_mbrtu(void)
|
|
{
|
|
static unsigned int mbrtu_port = 0;
|
|
|
|
/* Make sure to use Modbus RTU Preferences field to determine default TCP port */
|
|
|
|
if(mbrtu_port != 0 && mbrtu_port != global_mbus_rtu_port){
|
|
dissector_delete_uint("tcp.port", mbrtu_port, mbrtu_handle);
|
|
}
|
|
|
|
if(global_mbus_rtu_port != 0 && mbrtu_port != global_mbus_rtu_port) {
|
|
dissector_add_uint("tcp.port", global_mbus_rtu_port, mbrtu_handle);
|
|
}
|
|
|
|
mbrtu_port = global_mbus_rtu_port;
|
|
|
|
dissector_add_uint("mbtcp.prot_id", MODBUS_PROTOCOL_ID, modbus_handle);
|
|
dissector_add_for_decode_as("rtacser.data", mbrtu_handle);
|
|
|
|
}
|
|
|
|
/*
|
|
* Editor modelines
|
|
*
|
|
* Local Variables:
|
|
* c-basic-offset: 4
|
|
* tab-width: 8
|
|
* indent-tabs-mode: nil
|
|
* End:
|
|
*
|
|
* ex: set shiftwidth=4 tabstop=8 expandtab:
|
|
* :indentSize=4:tabSize=8:noTabs=true:
|
|
*/
|