LwIP接收数据出现Hard fault，求解决

发布于 2012-08-25 13:54:05 浏览：11751 订阅该版

CPU:LM3S9B92
系统版本：RT-Thread 1.0.2

1.在RTT上建立了一个TCP server线程，代码如下：
a.线程初始化源代码：
```
int rt_application_init()
{

rt_thread_t init_thread;

init_thread = rt_thread_create("init",
								rt_init_thread_entry, RT_NULL,
								1024, 21, 20);
	rt_thread_startup(init_thread);

#ifdef RT_USING_LWIP
	static struct rt_thread tcpserv_thread;
	rt_thread_init(&tcpserv_thread, 
				"tcpserv",
				tcpserv_thread_entry, RT_NULL,
				&tcpserv_thread_stack[0], sizeof(tcpserv_thread_stack),
				22, 20);
	rt_thread_startup(&tcpserv_thread);
#endif

return 0;
}
```

b.tcp server只是建立连接后一直等待接收，并把接收的字符串打印到串口,源代码如下，：
```#include <rtthread.h>
#include <lwip/sockets.h>

char tcpserv_thread_stack[512];

static const char send_data[] = "This is TCP Server from RT-Thread.";
static char recv_data[1024];

int init_tcpserver(rt_uint16_t port)
{
	int sock;
	struct sockaddr_in server_addr;

/* 一个socket在使用前，需要预先创建出来，指定SOCKSTREAM为TCP的socket */
	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
	{
   		/* 创建失败的错误处理*/
		rt_kprintf("Socket error
");
	   
		return -1;
	}

/* 初始化服务端地址*/
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(port);  /* 服务端工作的端口*/
	server_addr.sin_addr.s_addr = INADDR_ANY;
	rt_memset(&(server_addr.sin_zero),8, sizeof(server_addr.sin_zero));

/* 绑定socket到服务端地址*/
	if (bind(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1)
	{
		/* 绑定失败*/
		rt_kprintf("Unable to bind
");
	   
		return -1;
	}

/* 在socket上进行监听*/
	if (listen(sock, 5) == -1)
	{
		rt_kprintf("Listen error
");
	   
		return -1;
	}
	
	return sock;
}

void tcpserv_thread_entry(void* parameter)
{
	rt_uint32_t sin_size;
	int ret, bytes_received;	
	int sock, connected;
	struct sockaddr_in client_addr;
	fd_set readset;
	fd_set writeset;
	struct timeval timeout;

ret = -1;
	bytes_received = -1;
	timeout.tv_sec = 1;
	timeout.tv_usec = 0;

sock = init_tcpserver(5000);

while(1)
	{
		sin_size = sizeof(struct sockaddr_in);

connected = accept(sock, (struct sockaddr *)&client_addr, &sin_size);

rt_kprintf("I got a connection from (%s , %d)
",
                  inet_ntoa(client_addr.sin_addr),ntohs(client_addr.sin_port));

while( connected >= 0 )
		{
			FD_ZERO(&readset);
			FD_ZERO(&writeset); 
			FD_SET(connected, &readset);
			FD_SET(connected, &writeset);

ret = select(connected+1, &readset, &writeset, 0, &timeout);
			
			if( ret == -1 )
			{	
				lwip_close(connected);
				rt_kprintf("select error.
");
				break;
			}
			else if( ret == 0 )
			{
				/* timeout */
				rt_kprintf("select timeout.
");
			}
			else
			{
				if( FD_ISSET(connected, &readset) )  /* connected 是否可读 */
				{
					bytes_received = recv(connected, recv_data, 1024, 0);
		           	if (bytes_received <= 0)
		           	{
		            	lwip_close(connected);
		            	break;
		           	}
		           	else
		           	{
		           		recv_data[bytes_received] = '�';
		           		rt_kprintf("RECIEVED DATA = %s 
" , recv_data);
		           	}
				}
				
				if( FD_ISSET(connected, &writeset) ) /* connected 是否可写 */
				{
					//send(connected, send_data, strlen(send_data), 0);
				}
			}
		}
	}

lwip_close(sock);

return ;
}```

2.在PC上连接RTT上的tcp server,建立连接后，PC一直发送数据给tcp server.大约1分钟，出现hard fault，如下：
```
 pc: 0x0000f238
 lr: 0x000128dd
r12: 0x0000000a
r03: 0x0000a8c0
r02: 0xff00a8c0
r01: 0x20004c94
r00: 0x0000c068
hard fault on thread: tcpip
 thread  pri  status      sp     stack size max used   left tick  error
-------- ---- ------- ---------- ---------- ---------- ---------- ---
tcpip    0x0c ready   0x000000ac 0x00000400 0x000001e4 0x00000013 000
tidle    0x1f ready   0x0000004c 0x00000100 0x0000005c 0x00000004 000
tshell   0x14 suspend 0x00000070 0x00000800 0x00000070 0x0000000a 000
tcpserv  0x16 ready   0x000000a4 0x00000200 0x00000154 0x00000009 000
etx      0x0f suspend 0x00000084 0x00000200 0x00000084 0x00000010 000
erx      0x0f ready   0x000000a4 0x00000200 0x000000a4 0x00000010 000
```

根据出现hard fault时候的PC值，我找到发生错误的地方是在udp_input函数中，如下图：
![QQ截图20120825135317.png](/uploads/2828_48a57c68ced56fcef39da55d26dca771.png)

4.PC上的客户端软件，如下：
![QQ截图20120825135530.png](/uploads/2828_587fceab2ee8a57b86f215c6b9a0c832.png)