tcpser.c

linux系统下面实现modbustcp协议的通讯

/*******************************************************************************
File name:	tcps1.c

  Description:
  This program demo 
  how to use socket lib coding TCP Server program on UC7000/DA-600 series.
  
	The Hardware connection is following:
	[UC7000/DA-600 series]--- ~~LAN~~ ---PC Host Example (Windows platform)
	
	  If data received from Ethernet,send them all back to the LAN port.
	  1. Create TCP/IP socket. 
	  2. Socket Listen on TCP Port 4001.
	  3. If TCP connection is established, R/W data.
	  
		Usage:
		1. Make downloading file (tcps1-release or tcps1-debug) for UC7000/DA-600 series 
		1.1 Create executable file from source code(*.c) 
		1.1.1 Modify tcps1.c: 
		change "TCPPORT" if needed.
		1.1.2 Compiler and link to make tcps1-release (no debug message) or tcps1-debug (with debug message) 
		2. Download executable file to UC7000/DA-600 series 
		3. Run Application on UC7000/DA-600 series 
		4. Execute TCP Client example for PC.[tcpclient.exe or frmClient.exe]
    	   input the TCP Port number equal to "TCPPORT"
		   UC7000/DA-600 series Server ip equal to UC7000/DA-600 series IP adddress.
		   5. user can check if the sended data received back. 
		   
			 History:    
			 Version		Author		Date		Comment
			 1.0		Victor Yu.	01-15-2004      Wrote it.
*******************************************************************************/
#include        <stdio.h>
#include        <stdlib.h>
#include        <sys/types.h>
#include        <sys/socket.h>
#include        <netinet/in.h>
#include        <errno.h>
#include"comlib.h"
#include"comlib.c"

#define TCPPORT	502

#define TESTLEN	1024

char buf[TESTLEN]; 
unsigned short ReadBuff[1024];
unsigned short WriteBuff[1024];
unsigned char TxBuff[400];

struct ModTcpRecv
{
	unsigned char transaction_identifier[2];
	unsigned char protocol_identifier[2];
	unsigned char length_field_hi;
	unsigned char length_field_lo;
	unsigned char unit_identifier;
	unsigned char function_code;
	unsigned char ptr_hi;
	unsigned char ptr_lo;
	unsigned char len_hi;
	unsigned char len_lo;
}*pModTcpRecv;

struct ModTcpSend
{
	unsigned char transaction_identifier[2];
	unsigned char protocol_identifier[2];
	unsigned char length_field_hi;
	unsigned char length_field_lo;
	unsigned char unit_identifier;
	unsigned char function_code;
	unsigned char byte_count;
	unsigned char buff[300];
}*pModTcpSend;

struct ModTcpWrite
{
	unsigned char transaction_identifier[2];
	unsigned char protocol_identifier[2];
	unsigned char length_field_hi;
	unsigned char length_field_lo;
	unsigned char unit_identifier;
	unsigned char function_code;
	unsigned char ptr_hi;
	unsigned char ptr_lo;
	unsigned char nData_hi;
	unsigned char nData_lo;
}*pModTcpWrite;

int ChangeHiLo(unsigned short *ptr,unsigned int len)  //change unsigned data high byte and low byte to modscan look easy
{
    int i;
    unsigned char temp[2];
    unsigned short old,new1;
    for(i=0;i<len;i++)
    {  old=*ptr;
       temp[0]=(old & 0xff00) >>8;
       temp[1]=(old & 0xff);
       new1=temp[1]*256+temp[0];
       *ptr=new1;
       ptr++;
    }
    return(0);
}

int ModTcpDeal(unsigned char *pInBuff,unsigned char *pOutBuff)
{
	unsigned char *pByte;
	int i;
	pModTcpRecv=(struct ModTcpRecv *)pInBuff;
	pModTcpSend=(struct ModTcpSend *)pOutBuff;
	pModTcpSend->transaction_identifier [0]=pModTcpRecv->transaction_identifier [0];	
	pModTcpSend->transaction_identifier [1]=pModTcpRecv->transaction_identifier [1];
	pModTcpSend->protocol_identifier [0]=pModTcpRecv->protocol_identifier [0];
	pModTcpSend->protocol_identifier [1]=pModTcpRecv->protocol_identifier [1];
	pModTcpSend->length_field_hi =0x00;
	pModTcpSend->length_field_lo =(unsigned char)(3+pModTcpRecv->len_lo *2) ;
	if(0x03==pModTcpRecv->function_code )
	{
		pByte=(unsigned char *)WriteBuff+(pModTcpRecv->ptr_hi *256+pModTcpRecv->ptr_lo)*2 ;
		pModTcpSend->unit_identifier =pModTcpRecv->unit_identifier ;
		pModTcpSend->function_code =pModTcpRecv->function_code ;
		pModTcpSend->byte_count =pModTcpRecv->len_lo *2;
		for(i=0;i<pModTcpRecv->len_lo *2;i++)
		{
			pModTcpSend->buff [i]=*pByte;
			pByte++;
		}
		ChangeHiLo((unsigned short *)pModTcpSend->buff,pModTcpRecv->len_lo);
		return (sizeof(struct ModTcpSend)-300+i);
	}
	if(0x04==pModTcpRecv->function_code )
	{
		pByte=(unsigned char *)ReadBuff+(pModTcpRecv->ptr_hi *256+pModTcpRecv->ptr_lo)*2 ;
		pModTcpSend->unit_identifier =pModTcpRecv->unit_identifier ;
		pModTcpSend->function_code =pModTcpRecv->function_code ;
		pModTcpSend->byte_count =pModTcpRecv->len_lo *2;
		for(i=0;i<pModTcpRecv->len_lo *2;i++)
		{
			pModTcpSend->buff [i]=*pByte;
			pByte++;
		}
		ChangeHiLo((unsigned short *)pModTcpSend->buff,pModTcpRecv->len_lo);
		return (sizeof(struct ModTcpSend)-300+i);
	}

	if(0x06==pModTcpRecv->function_code )
	{
		pByte=(unsigned char *)WriteBuff+(pModTcpRecv->ptr_hi *256+pModTcpRecv->ptr_lo)*2 ;
		pModTcpWrite=(struct ModTcpWrite *)pInBuff;
		*(pByte+0)=pModTcpWrite->nData_lo ;
		*(pByte+1)=pModTcpWrite->nData_hi;
		for(i=0;i<sizeof(struct ModTcpWrite);i++)
		{
			*(pOutBuff+i)=*(pInBuff+i);
		}

		return sizeof(struct ModTcpWrite);
	}
	return 0;



	//return 0;
}


int main()
{
	int			sListen, sClient;
	int 			size,len,nRet,i;	
	struct sockaddr_in	local, client;
	
	//printf("sizeof(short)=%d\n",sizeof(short));
	for(i=0;i<1024;i++) ReadBuff[i]=i+1;
	for(i=0;i<1024;i++) WriteBuff[i]=i;
	//ChangeHiLo(ReadBuff,i);

	printf("create socket......");
	if ( (sListen=socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0 )
	{
		printf("fail [%d]\n", errno);
		return 0;
	} else 
		printf("OK\n");
	
	local.sin_addr.s_addr = htonl(INADDR_ANY);
	local.sin_family = AF_INET;
	local.sin_port = htons(TCPPORT);
	
	printf("socket bind......");
	if ( bind(sListen, (struct sockaddr *)&local, sizeof(local)) < 0 ) 
	{
		printf("fail [%d]\n", errno);
		return 0;
	} else
		printf("OK\n");
	
	printf("socket listen......");
	if (listen(sListen,1) < 0)
	{
		printf("fail [%d]\n", errno);
		return 0;
	} else
		printf("OK\n");
	
	size = sizeof(client);
	printf("accept......");
	if ( (sClient=accept(sListen, (struct sockaddr *)&client, &size)) < 0 )
	{
		printf("fail [%d]", errno);
		return 0;
	} else 
		printf("OK\n");
	
	printf("ready to recv & write data\n");
	while(1) 
	{
		len = recv(sClient, buf, TESTLEN, 0);
		if ( len > 0 ) 
		{	
			PrintHexLog(stderr,buf,len);
			//
			nRet=ModTcpDeal((unsigned char *)buf,TxBuff);
			if(nRet>0)
			{
				PrintHexLog(stderr,TxBuff,nRet);
				/*
				pModTcpRecv=(struct ModTcpRecv *)buf;
				//pModTcpRecv->unit_identifier 
				printf("pModTcpRecv->unit_identifier  =%X\n",pModTcpRecv->unit_identifier   );
				printf("pModTcpRecv->function_code=%X\n",pModTcpRecv->function_code);
				printf("pModTcpRecv->ptr_hi =%X\n",pModTcpRecv->ptr_hi );
				printf("pModTcpRecv->ptr_lo =%X\n",pModTcpRecv->ptr_lo );
				printf("pModTcpRecv->len_hi  =%X\n",pModTcpRecv->len_hi  );
				printf("pModTcpRecv->len_lo  =%X\n",pModTcpRecv->len_lo  );*/
				//if (send(sClient,buf,len,0) <= 0) 
				if (send(sClient,TxBuff,nRet,0) <= 0) 
				{
					printf("send fail [%d]\n", errno);
					break;
				}
			}
		} 
		else if ( len == 0 )
		{
			printf("disconnect\n");
			break;
		} 
		else if ( len < 0 ) 
		{
			printf("recv fail [%d]", errno);
			break;
		} 
	}
	
	printf("close socket\n");	
	close(sListen);
	close(sClient);
	
	return 0;
}