Diff: mbtcp.cpp

Revision:

1:a3ee8cb24540

diff -r 0453a0a7e500 -r a3ee8cb24540 mbtcp.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbtcp.cpp	Mon Jul 02 14:36:46 2018 +0000
@@ -0,0 +1,159 @@
+/* 
+ * FreeModbus Libary: 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.
+ *
+ * File: $Id: mbtcp.c,v 1.3 2006/12/07 22:10:34 wolti Exp $
+ */
+
+/* ----------------------- System includes ----------------------------------*/
+#include "stdlib.h"
+#include "string.h"
+
+/* ----------------------- Platform includes --------------------------------*/
+#include "port.h"
+
+/* ----------------------- Modbus includes ----------------------------------*/
+#include "mb.h"
+#include "mbconfig.h"
+#include "mbtcp.h"
+#include "mbframe.h"
+#include "mbport.h"
+
+#if MB_TCP_ENABLED > 0
+
+/* ----------------------- Defines ------------------------------------------*/
+
+/* ----------------------- 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 */
+
+
+/* ----------------------- Start implementation -----------------------------*/
+eMBErrorCode
+eMBTCPDoInit( USHORT 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( UCHAR * pucRcvAddress, UCHAR ** ppucFrame, USHORT * pusLength )
+{
+    eMBErrorCode    eStatus = MB_EIO;
+    UCHAR          *pucMBTCPFrame;
+    USHORT          usLength;
+    USHORT          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( UCHAR _unused, const UCHAR * pucFrame, USHORT usLength )
+{
+    eMBErrorCode    eStatus = MB_ENOERR;
+    UCHAR          *pucMBTCPFrame = ( UCHAR * ) pucFrame - MB_TCP_FUNC;
+    USHORT          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
+