智能家居服务发现实现

服务设备软件架构设计

代码复用

将网络通信框架移植到开发板，之后，可以使用框架中的组件实现 Response Task 和 Service Task。

框架移植注意事项

LWIP 是微型 TCP/IP 协议栈 (并非完整 TCP/IP 协议栈)

支持 socket 接口，但一些功能未实现

socket 接口所在头文件不同于 Linux 和 Windows 平台

完成可移植性测试，对测试中出现的问题及时修复

可移植性测试

通过网络调试助手验证 TCP 数据收发

• 设备端运行服务端，客户端连接，数据收发功能

通过网络调试助手验证 UDP 数据收发

• 设备接收广播，并回复数据

Service Task 关键实现

Response Task 关键实现

网络通信框架移植

main_entry.c

#include 
#include "ohos_init.h"
#include "cmsis_os2.h"
#include "wifi_connect.h"
#include "response_task.h"
#include "service_task.h"
 
static void* Task_Init(const char* arg)
{
	Wifi_Init();
    Wifi_Connect("wifi_test", "12345678");
    Wifi_Start();
 
    if(Wifi_IsOk)
    {
        osThreadAttr_t attr = {0};

        printf("connect wifi success! ip = %s\n", Wifi_IpAddr());
 
        attr.name = "Response Task";
        attr.stack_size = 4 * 1024;
        attr.priority = 20;

        if(osThreadNew((osThreadFunc_t)Response_Task, NULL, &attr) == NULL)
        {
            printf("failed to create response task!\n");
        }

        attr.name = "Service Task";
        attr.stack_size = 4 * 1024;
        attr.priority = 20;

        if(osThreadNew((osThreadFunc_t)Service_Task, NULL, &attr) == NULL)
        {
            printf("failed to create service task!\n");
        }
    }
	
	return arg;
}
 
static void Main_Entry(void)
{
    osThreadAttr_t attr = {0};
 
    attr.name = "Task_Iniit";
    attr.stack_size = 4 * 1024;
    attr.priority = 20;
 
    if(osThreadNew((osThreadFunc_t)Task_Init, NULL, &attr) == NULL)
	{
		printf("failed to create task!\n");
	}
}
 
SYS_RUN(Main_Entry);

response_task.h

#ifndef RESPONSE_TASK
#define RESPONSE_TASK

void* Response_Task(const char* arg);

#endif

response_task.c

#include 
#include "response_task.h"
#include "udp_point.h"

void* Response_Task(const char* arg)
{
    UdpPoint* point = NULL;
    Message* msg = NULL;
    char remote[16] = {0};
    int port = 0;

    point = UdpPoint_New(9999);

    if(point)
    {
        printf("point = 0x%X\n", point);

        while(1)
        {
            msg = UdpPoint_RecvMsg(point, remote, &port);

            if(msg != NULL)
            {
                printf("msg = 0x%X\n", msg);
                printf("receive a message, ip = %s, port = %d\n", remote, port);
                printf("type = %d, cmd = %d, index = %d, total = %d, lengh = %d\n", msg->type, msg->cmd,msg->index, msg->total, msg->length);

                if(msg->length > 0)
                {
                    printf("data: %s\n", msg->payload);
                }

                free(msg);
            }
        }

        UdpPoint_Del(point);
    }

    return NULL;
}

service_task.h

#ifndef SERVICE_TASK_H
#define SERVICE_TASK_H

void* Service_Task(const char* arg);

#endif

service_task.c

#include 
#include "service_task.h"
#include "tcp_server.h"

static void Server_Listener_Handler(TcpClient* client, int evt)
{
    if(evt == EVT_COON)
    {
        printf("a client connect\n");
    }
    else if(evt == EVT_DATA)
    {
        Message* msg = NULL;

        msg = TcpClient_RecvMsg(client);

        if(msg)
        {
            printf("msg = 0x%X\n", msg);
            printf("type = %d, cmd = %d, index = %d, total = %d, lengh = %d\n", msg->type, msg->cmd,msg->index, msg->total, msg->length);

            if(msg->length > 0)
            {
                printf("data: %s\n", msg->payload);
            }

            free(msg);
        }
    }
    else if(evt == EVT_CLOSE)
    {
        printf("a client left\n");
    }

    return NULL;
}

void* Service_Task(const char* arg)
{
    TcpServer* server = NULL;

    server = TcpServer_New();

    if(server)
    {
        printf("server = 0x%X\n", server);

        TcpServer_SetListener(server, Server_Listener_Handler);
        TcpServer_Start(server, 8888, 5);
        TcpServer_DoWork(server);

        TcpServer_Del(server);
    }

    return NULL;
}

问题及原因

LWIP 未实现选项组合 IPPORTO_TCP，TCP_INFO

int TcpClient_IsValid(TcpClient* client); 总是返回假，导致服务端逻辑错误

MParser 从内存解析数据且内存中的协议消息无 payload (length == 0)

Mparser 无法将解析状态推到最终态，导致解析结果为 NULL

实验结果

我们使用 UdpPoint 能够成功地收发数据

 

 TCP 通信框架我们也成功的移植了过来，测试了并没有问题。

课后思考

Response Task 和 Service Task 的业务逻辑如何实现？客户端如何实现？