介绍

tcp作为服务端，监听端口8888，实现串口透传，这里是使用select监听tcp的receive和串口的read，单工通信

-p 指定tcp端口

-s 指定串口

-b 指定波特率 支持4800 9600 115200

-? 打印具体用法

##程序

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

void Test_err(int flg)

{

if(flg<0)

{

perror(strerror(errno));

exit(1);

}

}

int main(int argc, char** argv)

{

printf("usage : %s ?\n",argv[0]);

short listenPort=8888;

unsigned char uart_port[100]={"/dev/ttyS2"};

int bps=0;

unsigned int baudRate= B9600;

int opt;

while ((opt=getopt(argc,argv,"p:s:b:?")) != -1)

{

switch (opt)

{

case 'p':

listenPort = atoi(optarg);

break;

case 's':

memset(uart_port,0,sizeof(uart_port));

strncpy(uart_port,optarg,99);

break;

case 'b':

bps = atoi(optarg);

break;

default: /* '?' */

fprintf(stderr, "Usage: %s [-p port -s serial port -b baund] \n",

argv[0]);

exit(EXIT_FAILURE);

}

}

switch(bps)

{

case 4800:

baudRate=B4800;

break;

case 19200:

baudRate=B19200;

break;

case 38400:

baudRate=B38400;

break;

case 57600:

baudRate=B57600;

break;

case 115200:

baudRate=B115200;

break;

default:

baudRate=B9600;

bps=9600;

break;

}

printf("tcp-server...enter\n");

printf("set uartport is %d\n",bps);

printf("set uartspeed is %s\n",uart_port);

printf("set tcpport is %d\n",listenPort);

// uart--------------------------------------------------------

int uart_fd=open(uart_port, O_RDWR | O_NOCTTY | O_NDELAY);

struct termios newtio;

memset(&newtio,0, sizeof( newtio ));

newtio.c_cflag=0;

newtio.c_iflag=0;

newtio.c_cflag |= CLOCAL | CREAD;

newtio.c_cflag &= ~CSIZE;

newtio.c_cflag |= CS8;

newtio.c_cflag &= ~PARENB;

newtio.c_cflag &= ~CSTOPB;

newtio.c_cc[VTIME] = 0;

newtio.c_cc[VMIN] = 0;

cfsetispeed(&newtio, baudRate);

cfsetispeed(&newtio, baudRate);

tcflush(uart_fd,TCIFLUSH);

if((tcsetattr(uart_fd,TCSANOW,&newtio))!=0)

{

perror("uart open error\n");

return -1;

}

int portfd;

#if (__GNUC__ == 4 && __GNUC_MINOR__ == 3)

struct my_serial_rs485 rs485conf;

struct my_serial_rs485 rs485conf_bak;

#else

struct serial_rs485 rs485conf;

struct serial_rs485 rs485conf_bak;

#endif

portfd=uart_fd;

/* Driver-specific ioctls: ...\linux-3.10.x\include\uapi\asm-generic\ioctls.h */

#define TIOCGRS485 0x542E

#define TIOCSRS485 0x542F

if (ioctl (portfd, TIOCGRS485, &rs485conf) < 0)

{

/* Error handling.*/

// Log::Inf("ioctl TIOCGRS485 error.\n");

printf( "[ERR] ioctl TIOCGRS485 error.\n");

}

/* Enable RS485 mode: */

rs485conf.flags |= SER_RS485_ENABLED;

/* Set logical level for RTS pin equal to 1 when sending: */

rs485conf.flags |= SER_RS485_RTS_ON_SEND;

//rs485conf.flags |= SER_RS485_RTS_AFTER_SEND;

/* set logical level for RTS pin equal to 0 after sending: */

rs485conf.flags &= ~(SER_RS485_RTS_AFTER_SEND);

//rs485conf.flags &= ~(SER_RS485_RTS_ON_SEND);

/* Set rts delay after send, if needed: */

rs485conf.delay_rts_after_send = 0x80;

if (ioctl (portfd, TIOCSRS485, &rs485conf) < 0)

{

/* Error handling.*/

printf("ioctl TIOCSRS485 error.\n");

}

if (ioctl (portfd, TIOCGRS485, &rs485conf_bak) < 0)

{

/* Error handling.*/

printf("ioctl TIOCGRS485 error.\n");

}

/*----------------------------------------------------*/

unsigned char test_msg[]="this is send by uart\n";

int uart_sent_cnt = write(uart_fd, test_msg, sizeof(test_msg));

// tcp--------------------------------------------------------

int listen_fd=-1;

int accept_fd=-1;

int flags;

int max_listen_num=10;

unsigned char r_buf[255];

int n;

struct sockaddr_in server_addr;

struct sockaddr_in clinet_addr;

listen_fd=socket(AF_INET, SOCK_STREAM, 0);

Test_err(listen_fd);

memset(&server_addr,0,sizeof(server_addr));

server_addr.sin_family = AF_INET;

server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

server_addr.sin_port = htons(listenPort);

int i = 1;/* 允许重复使用本地地址与套接字进行绑定 */

setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));

flags=bind(listen_fd, (struct sockaddr *)&server_addr,sizeof(struct sockaddr));

Test_err(flags);

flags= listen(listen_fd, max_listen_num);

Test_err(flags);

int clinet_addr_len=sizeof(clinet_addr);

__ACCEPT_AGAIN__:

accept_fd= accept(listen_fd, (struct sockaddr *)&clinet_addr, &clinet_addr_len);

// show clinet message

printf("accept_fd is %d \n",accept_fd);

printf("port=%d\n",ntohs(clinet_addr.sin_port));

unsigned char strbuf[20];

inet_ntop(AF_INET,&clinet_addr.sin_addr,strbuf,sizeof(strbuf));

printf("ip=%s\n",strbuf);

memset(r_buf , 0, sizeof(r_buf));

int maxfd;

fd_set rset, allset;

struct timeval tv;

FD_ZERO(&allset);

FD_SET(uart_fd, &allset);

FD_SET(accept_fd, &allset);

memset(&tv, 0, sizeof(tv));

tv.tv_usec = 1000 * 1000;

int len=0;

while (accept_fd)

{

rset=allset;

maxfd=(accept_fd>uart_fd?accept_fd:uart_fd);

flags=select(maxfd + 1, &rset, NULL, NULL, &tv);

Test_err(flags);

// get from tcp>>>>>uart

if (FD_ISSET(accept_fd, &rset))

{

n = recv(accept_fd, r_buf, 100, 0);

Test_err(n);

if(n)

{

//write(0,r_buf,n);

printf("Get from tcp %d\n",n);

write(uart_fd,r_buf,n);

}

else

{

printf("socket is disconnect\n");

goto __ACCEPT_AGAIN__;

}

}

// get from uart>>>>tcp

else if (FD_ISSET(uart_fd, &rset))

{

usleep(100000);//100ms 这里等待接受多一点的数据

int ret = read(uart_fd, (char*)r_buf,sizeof(r_buf));

if (ret < 0)

{

if ((errno == EAGAIN) ||

(errno == EWOULDBLOCK) ||

(errno == EINTR))

{

printf("Serial,read timeout error:%s. ignore ti!!!", strerror(errno));

ret = 0;

}

}

else

{

printf("Get from uart %d\n",ret);

send(accept_fd, r_buf, ret, 0);

}

}

}

printf("tcp-server...exit\n");

return 0;

}