基于LwIP socket的TCP服务器

上篇文章介绍了TCP客户端编写方法，这篇文章主要介绍TCP服务器的编写步骤方法，其流程如下所示

1、创建一个基于流的socket

2、设置本地服务器IP地址及端口号

3、绑定创建的socket和本地IP地址及端口信息

4、监听该socket（listen）

5、接受该socket（accept）

6、发送、接收数据

经过了以上几个步骤以后，一个简单的服务器就创建起来了，TCP服务器主要是多了监听和接受两个步骤，少了连接步骤，其源代码如下所示

#include 
#include 
#include 

#define	PORT			50000

RAW_U8 data_buffer[100];

static void tcp_server_thread(void *p_arg)
{
	struct sockaddr_in server_addr;
	struct sockaddr_in conn_addr;
	int sock_fd;				/* server socked */
	int sock_conn;			/* request socked */
	socklen_t addr_len;
	int err;
	int length;
	int count = 0;
	
	
	sock_fd = socket(AF_INET, SOCK_STREAM, 0);
	if (sock_fd == -1) {
		Uart_Printf("failed to create sock_fd!\n");
		RAW_ASSERT(0);
	}
	
	raw_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(PORT);
	
	err = bind(sock_fd, (struct sockaddr *)&server_addr, sizeof(server_addr));
	if (err < 0) {
		RAW_ASSERT(0);
	}
	
	err = listen(sock_fd, 1);
	if (err < 0) {
		RAW_ASSERT(0);
	}

	addr_len = sizeof(struct sockaddr_in);
	
	Uart_Printf("before accept!\n");
	sock_conn = accept(sock_fd, (struct sockaddr *)&conn_addr, &addr_len);
	Uart_Printf("after accept!\n");
	
	while (1) {
		raw_memset(data_buffer, 0, sizeof(data_buffer));
		
		length = recv(sock_conn, (unsigned int *)data_buffer, 20, 0);
		
		Uart_Printf("length received %d\n", length);
		Uart_Printf("received string: %s\n", data_buffer);
		Uart_Printf("received count: %d\n", count);

		send(sock_conn, "good", 5, 0);
	}
}

void tcp_server_init(void)
{
	sys_thread_new("tcp_server_thread",  tcp_server_thread, NULL, DEFAULT_THREAD_STACKSIZE, DEFAULT_THREAD_PRIO - 1);
}