| /**************************************************************************** |
| * apps/modbus/tcp/mbtcp.c |
| * |
| * FreeModbus Library: A portable Modbus implementation for Modbus ASCII/RTU. |
| * Copyright (c) 2006 Christian Walter <wolti@sil.at> |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| #include <nuttx/config.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "modbus/mb.h" |
| |
| #include "port.h" |
| #include "mbtcp.h" |
| |
| #ifdef CONFIG_MB_TCP_ENABLED |
| |
| /**************************************************************************** |
| * Pre-processor Definitions |
| ****************************************************************************/ |
| |
| /* ----------------------- MBAP Header --------------------------------------*/ |
| /* |
| * |
| * <------------------------ MODBUS TCP/IP ADU(1) -------------------------> |
| * <----------- MODBUS PDU (1') ----------------> |
| * +-----------+---------------+------------------------------------------+ |
| * | TID | PID | Length | UID |Code | Data | |
| * +-----------+---------------+------------------------------------------+ |
| * | | | | | |
| * (2) (3) (4) (5) (6) |
| * |
| * (2) ... MB_TCP_TID = 0 (Transaction Identifier - 2 Byte) |
| * (3) ... MB_TCP_PID = 2 (Protocol Identifier - 2 Byte) |
| * (4) ... MB_TCP_LEN = 4 (Number of bytes - 2 Byte) |
| * (5) ... MB_TCP_UID = 6 (Unit Identifier - 1 Byte) |
| * (6) ... MB_TCP_FUNC = 7 (Modbus Function Code) |
| * |
| * (1) ... Modbus TCP/IP Application Data Unit |
| * (1') ... Modbus Protocol Data Unit |
| */ |
| |
| #define MB_TCP_TID 0 |
| #define MB_TCP_PID 2 |
| #define MB_TCP_LEN 4 |
| #define MB_TCP_UID 6 |
| #define MB_TCP_FUNC 7 |
| |
| #define MB_TCP_PROTOCOL_ID 0 /* 0 = Modbus Protocol */ |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| eMBErrorCode eMBTCPDoInit(uint16_t ucTCPPort) |
| { |
| eMBErrorCode eStatus = MB_ENOERR; |
| |
| if (xMBTCPPortInit(ucTCPPort) == false) |
| { |
| eStatus = MB_EPORTERR; |
| } |
| |
| return eStatus; |
| } |
| |
| void eMBTCPStart(void) |
| { |
| } |
| |
| void eMBTCPStop(void) |
| { |
| /* Make sure that no more clients are connected. */ |
| |
| vMBTCPPortDisable(); |
| } |
| |
| eMBErrorCode eMBTCPReceive(uint8_t *pucRcvAddress, uint8_t **ppucFrame, uint16_t *pusLength) |
| { |
| eMBErrorCode eStatus = MB_EIO; |
| uint8_t *pucMBTCPFrame; |
| uint16_t usLength; |
| uint16_t usPID; |
| |
| if (xMBTCPPortGetRequest(&pucMBTCPFrame, &usLength) != false) |
| { |
| usPID = pucMBTCPFrame[MB_TCP_PID] << 8U; |
| usPID |= pucMBTCPFrame[MB_TCP_PID + 1]; |
| |
| if (usPID == MB_TCP_PROTOCOL_ID) |
| { |
| *ppucFrame = &pucMBTCPFrame[MB_TCP_FUNC]; |
| *pusLength = usLength - MB_TCP_FUNC; |
| eStatus = MB_ENOERR; |
| |
| /* Modbus TCP does not use any addresses. Fake the source address such |
| * that the processing part deals with this frame. |
| */ |
| |
| *pucRcvAddress = MB_TCP_PSEUDO_ADDRESS; |
| } |
| } |
| else |
| { |
| eStatus = MB_EIO; |
| } |
| |
| return eStatus; |
| } |
| |
| eMBErrorCode eMBTCPSend(uint8_t _unused, const uint8_t * pucFrame, uint16_t usLength) |
| { |
| eMBErrorCode eStatus = MB_ENOERR; |
| uint8_t *pucMBTCPFrame = (uint8_t *) pucFrame - MB_TCP_FUNC; |
| uint16_t usTCPLength = usLength + MB_TCP_FUNC; |
| |
| /* The MBAP header is already initialized because the caller calls this |
| * function with the buffer returned by the previous call. Therefore we |
| * only have to update the length in the header. Note that the length |
| * header includes the size of the Modbus PDU and the UID Byte. Therefore |
| * the length is usLength plus one. |
| */ |
| |
| pucMBTCPFrame[MB_TCP_LEN] = (usLength + 1) >> 8U; |
| pucMBTCPFrame[MB_TCP_LEN + 1] = (usLength + 1) & 0xFF; |
| if (xMBTCPPortSendResponse(pucMBTCPFrame, usTCPLength) == false) |
| { |
| eStatus = MB_EIO; |
| } |
| |
| return eStatus; |
| } |
| |
| #endif /* CONFIG_MB_TCP_ENABLED */ |