fix bug: frame data read from network was potentially being moved inside buffer (lb_normalize()) before it was processed by caller to read_frame()
/*
* Copyright (c) 2001,2016 Mario de Sousa (msousa@fe.up.pt)
*
* This file is part of the Modbus library for Beremiz and matiec.
*
* This Modbus library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this Modbus library. If not, see <http://www.gnu.org/licenses/>.
*
* This code is made available on the understanding that it will not be
* used in safety-critical situations without a full and competent review.
*/
#ifndef MODBUS_RTU_PRIVATE_H
#define MODBUS_RTU_PRIVATE_H
#include "mb_types.h" /* get the data types */
#include "mb_util.h"
/* serial port default configuration... */
#define DEF_DATA_BITS 8
#define DEF_STOP_BITS_PAR 1 /* default stop bits if parity is used */
#define DEF_STOP_BITS_NOP 2 /* default stop bits if parity is not used */
#define DEF_BAUD_RATE 9600
/* Send retries of rtu frames... */
#define RTU_FRAME_SEND_RETRY 1
/* NOTES:
* - the above are the retries at the layer1 level,
* higher layers may decide to retry for themselves!
*/
/* Buffer sizes... */
/* We use double the maximum frame length for the read buffer,
* due to the algorithm used to work around aborted frames.
*/
#define RECV_BUFFER_SIZE_SMALL (MAX_RTU_FRAME_LENGTH + 10)
#define RECV_BUFFER_SIZE_LARGE (2 * (MAX_RTU_FRAME_LENGTH))
/* Frame lengths... */
/* The number of bytes in each frame format, excluding CRC.
*
* BYTE_COUNT_3 denotes that third byte of frame contains the number of bytes;
* - total number of bytes in frame is
* BYTE_COUNT_3_HEADER + byte_count
* BYTE_COUNT_34 denotes that third+fourth bytes of frame contain the number of bytes;
* - total number of bytes in frame is
* BYTE_COUNT_34_HEADER + byte_count
* BYTE_COUNT_7 denotes that seventh byte of frame contain the number of bytes;
* - total number of bytes in frame is
* BYTE_COUNT_7_HEADER + byte_count
* BYTE_COUNT_11 denotes that eleventh byte of frame contain the number of bytes;
* - total number of bytes in frame is
* BYTE_COUNT_11_HEADER + byte_count
* BYTE_COUNT_U denotes unknown number of bytes;
*/
#define BYTE_COUNT_3_HEADER 3
#define BYTE_COUNT_34_HEADER 4
#define BYTE_COUNT_7_HEADER 7
#define BYTE_COUNT_11_HEADER 11
#define BYTE_COUNT_3 (-3)
#define BYTE_COUNT_34 (-34)
#define BYTE_COUNT_7 (-7)
#define BYTE_COUNT_11 (-11)
#define BYTE_COUNT_U (-128)
#define MAX_FUNCTION_CODE 0x18
#define MIN_FRAME_LENGTH 3
#define EXCEPTION_FRAME_LENGTH 3
static i8 query_frame_lengths[MAX_FUNCTION_CODE+1] = {
/* 0x00 */ 0, /* unused */
/* 0x01 */ 6, /* Read Coil Status */
/* 0x02 */ 6, /* Read Input Status */
/* 0x03 */ 6, /* Read Holding Registers */
/* 0x04 */ 6, /* Read Input Registers */
/* 0x05 */ 6, /* Force Single Coil */
/* 0x06 */ 6, /* Preset Single Register */
/* 0x07 */ 2, /* Read Exception Status */
/* 0x08 */ 4, /* Diagnostics */
/* 0x09 */ BYTE_COUNT_U, /* Program 484 */
/* 0x0A */ BYTE_COUNT_U, /* Poll 484 */
/* 0x0B */ 2, /* Fetch Comm. Event Counter */
/* 0x0C */ 2, /* Fetch Comm. Event Log */
/* 0x0D */ BYTE_COUNT_U, /* Program Controller */
/* 0x0E */ BYTE_COUNT_U, /* Poll Controller */
/* 0x0F */ BYTE_COUNT_7, /* Force Multiple Coils */
/* 0x10 */ BYTE_COUNT_7, /* Preset Multiple Registers */
/* 0x11 */ 2, /* Report Slave ID */
/* 0x12 */ BYTE_COUNT_U, /* Program 884/M84 */
/* 0x13 */ BYTE_COUNT_U, /* Reset. Comm. Link */
/* 0x14 */ BYTE_COUNT_3, /* Read General Reference */
/* 0x15 */ BYTE_COUNT_3, /* Write General Reference */
/* 0x16 */ 8, /* Mask Write 4X Register */
/* 0x17 */ BYTE_COUNT_11, /* Read/Write 4x Register */
/* 0x18 */ 4 /* Read FIFO Queue */
};
static i8 response_frame_lengths[MAX_FUNCTION_CODE+1] = {
/* 0x00 */ 0, /* unused */
/* 0x01 */ BYTE_COUNT_3, /* Read Coil Status */
/* 0x02 */ BYTE_COUNT_3, /* Read Input Status */
/* 0x03 */ BYTE_COUNT_3, /* Read Holding Registers */
/* 0x04 */ BYTE_COUNT_3, /* Read Input Registers */
/* 0x05 */ 6, /* Force Single Coil */
/* 0x06 */ 6, /* Preset Single Register */
/* 0x07 */ 3, /* Read Exception Status */
/* 0x08 */ 6,/*see (1)*/ /* Diagnostics */
/* 0x09 */ BYTE_COUNT_U, /* Program 484 */
/* 0x0A */ BYTE_COUNT_U, /* Poll 484 */
/* 0x0B */ 6, /* Fetch Comm. Event Counter */
/* 0x0C */ BYTE_COUNT_3, /* Fetch Comm. Event Log */
/* 0x0D */ BYTE_COUNT_U, /* Program Controller */
/* 0x0E */ BYTE_COUNT_U, /* Poll Controller */
/* 0x0F */ 6, /* Force Multiple Coils */
/* 0x10 */ 6, /* Preset Multiple Registers */
/* 0x11 */ BYTE_COUNT_3, /* Report Slave ID */
/* 0x12 */ BYTE_COUNT_U, /* Program 884/M84 */
/* 0x13 */ BYTE_COUNT_U, /* Reset. Comm. Link */
/* 0x14 */ BYTE_COUNT_3, /* Read General Reference */
/* 0x15 */ BYTE_COUNT_3, /* Write General Reference */
/* 0x16 */ 8, /* Mask Write 4X Register */
/* 0x17 */ BYTE_COUNT_3, /* Read/Write 4x Register */
/* 0x18 */ BYTE_COUNT_34 /* Read FIFO Queue */
};
/* NOTE (1):
* The diagnostic function (0x08) has sub-functions. In particular,
* sub-function 21 (0x15) has two sub-sub-functions. In the very
* particular case of *one* of these sub-sub-functions, the reply
* frame does *not* have a size of 4, but is variable in length
* and includes a byte counter.
* To take this into account in the table would require an extra two
* tables.
* The above length has been hardcoded into the frame_length() function
* (in file modbus_rtu.c)
*/
#define FALSE 0
#define TRUE 1
#endif /* MODBUS_RTU_PRIVATE_H */