[网络协议]HarmonyOS无线联网开发（WIFI AP热点，STA联网，UDP客户端）

HarmonyOS无线联网开发

WIFI AP热点

API介绍

wifi_hotspot.h接口简介

AP热点案例

#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include "cmsis_os2.h"
#include "ohos_init.h"

#include "wifi_device.h"
#include "wifi_hotspot.h"
#include "wifi_error_code.h"
#include "lwip/netifapi.h"


#define AP_SSID "BearPi"
#define AP_PSK  "0987654321"

#define ONE_SECOND 1
#define DEF_TIMEOUT 15

static void OnHotspotStaJoinHandler(StationInfo *info);
static void OnHotspotStateChangedHandler(int state);
static void OnHotspotStaLeaveHandler(StationInfo *info);

static struct netif *g_lwip_netif = NULL;
static int g_apEnableSuccess = 0;
WifiEvent g_wifiEventHandler = {0};
WifiErrorCode error;

static BOOL WifiAPTask(void)
{
    //延时2S便于查看日志
    osDelay(200);

    //注册wifi事件的回调函数
    g_wifiEventHandler.OnHotspotStaJoin = OnHotspotStaJoinHandler;
    g_wifiEventHandler.OnHotspotStaLeave = OnHotspotStaLeaveHandler;
    g_wifiEventHandler.OnHotspotStateChanged = OnHotspotStateChangedHandler;
    error = RegisterWifiEvent(&g_wifiEventHandler);
    if (error != WIFI_SUCCESS)
    {
        printf("RegisterWifiEvent failed, error = %d.\r\n",error);
        return -1;
    }
    printf("RegisterWifiEvent succeed!\r\n");
    //设置指定的热点配置
    HotspotConfig config = {0};

    strcpy(config.ssid, AP_SSID);
    strcpy(config.preSharedKey, AP_PSK);
    config.securityType = WIFI_SEC_TYPE_PSK;
    config.band = HOTSPOT_BAND_TYPE_2G;
    config.channelNum = 7;

    error = SetHotspotConfig(&config);
    if (error != WIFI_SUCCESS)
    {
        printf("SetHotspotConfig failed, error = %d.\r\n", error);
        return -1;
    }
    printf("SetHotspotConfig succeed!\r\n");

    //启动wifi热点模式
    error = EnableHotspot(); 
    if (error != WIFI_SUCCESS)
    {
        printf("EnableHotspot failed, error = %d.\r\n", error);
        return -1;
    }
    printf("EnableHotspot succeed!\r\n");

    //检查热点模式是否使能
    if (IsHotspotActive() == WIFI_HOTSPOT_NOT_ACTIVE)
    {
        printf("Wifi station is not actived.\r\n");
        return -1;
    }
    printf("Wifi station is actived!\r\n");

    //启动dhcp
    g_lwip_netif = netifapi_netif_find("ap0");
    if (g_lwip_netif) 
    {
        ip4_addr_t bp_gw;
        ip4_addr_t bp_ipaddr;
        ip4_addr_t bp_netmask;

        IP4_ADDR(&bp_gw, 192, 168, 1, 1);           /* input your gateway for example: 192.168.1.1 */
        IP4_ADDR(&bp_ipaddr, 192, 168, 1, 1);       /* input your IP for example: 192.168.1.1 */
        IP4_ADDR(&bp_netmask, 255, 255, 255, 0);    /* input your netmask for example: 255.255.255.0 */

        err_t ret = netifapi_netif_set_addr(g_lwip_netif, &bp_ipaddr, &bp_netmask, &bp_gw);
        if(ret != ERR_OK)
        {
            printf("netifapi_netif_set_addr failed, error = %d.\r\n", ret);
            return -1;
        }
        printf("netifapi_netif_set_addr succeed!\r\n");

        ret = netifapi_dhcps_start(g_lwip_netif, 0, 0);
        if(ret != ERR_OK)
        { 
            printf("netifapi_dhcp_start failed, error = %d.\r\n", ret);
            return -1;
        }
        printf("netifapi_dhcps_start succeed!\r\n");

    }

    /****************以下为UDP服务器代码***************/
	//在sock_fd 进行监听
    int sock_fd;
    //服务端地址信息
	struct sockaddr_in server_sock;

    //创建socket
	if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
	{
		perror("socket is error.\r\n");
		return -1;
	}

	bzero(&server_sock, sizeof(server_sock));
	server_sock.sin_family = AF_INET;
	server_sock.sin_addr.s_addr = htonl(INADDR_ANY);
	server_sock.sin_port = htons(8888);

	//调用bind函数绑定socket和地址
	if (bind(sock_fd, (struct sockaddr *)&server_sock, sizeof(struct sockaddr)) == -1)
	{
		perror("bind is error.\r\n");
		return -1;
	}

    int ret;
    char recvBuf[512] = {0};
    //客户端地址信息
    struct sockaddr_in client_addr;
    int size_client_addr= sizeof(struct sockaddr_in);
    while (1)
    {
        
        printf("Waiting to receive data...\r\n");
        memset(recvBuf, 0, sizeof(recvBuf));
        ret = recvfrom(sock_fd, recvBuf, sizeof(recvBuf), 0, (struct sockaddr*)&client_addr,(socklen_t*)&size_client_addr);
        if(ret < 0)
        {
            printf("UDP server receive failed!\r\n");
            return -1;
        }
        printf("receive %d bytes of data from ipaddr = %s, port = %d.\r\n", ret, inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
        printf("data is %s\r\n",recvBuf);
        ret = sendto(sock_fd, recvBuf, strlen(recvBuf), 0, (struct sockaddr *)&client_addr, sizeof(client_addr));
        if (ret < 0)
        {
            printf("UDP server send failed!\r\n");
            return -1;
        }
    }
    /*********************END********************/
}

static void HotspotStaJoinTask(void)
{
    static char macAddress[32] = {0};
    StationInfo stainfo[WIFI_MAX_STA_NUM] = {0};
    StationInfo *sta_list_node = NULL;
    unsigned int size = WIFI_MAX_STA_NUM;

    error = GetStationList(stainfo, &size);
    if (error != WIFI_SUCCESS) {
        printf("HotspotStaJoin:get list fail, error is %d.\r\n", error);
        return;
    }
    sta_list_node = stainfo;
    for (uint32_t i = 0; i < size; i++, sta_list_node++) {
    unsigned char* mac = sta_list_node->macAddress;
    snprintf(macAddress, sizeof(macAddress), "%02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
    printf("HotspotSta[%d]: macAddress=%s.\r\n",i, macAddress);
    }
    g_apEnableSuccess++;
}
static void OnHotspotStaJoinHandler(StationInfo *info)
{
    if (info == NULL) {
    printf("HotspotStaJoin:info is null.\r\n");
    } 
    else {
        printf("New Sta Join\n");
        osThreadAttr_t attr;
        attr.name = "HotspotStaJoinTask";
        attr.attr_bits = 0U;
        attr.cb_mem = NULL;
        attr.cb_size = 0U;
        attr.stack_mem = NULL;
        attr.stack_size = 2048;
        attr.priority = 24;
        if (osThreadNew((osThreadFunc_t)HotspotStaJoinTask, NULL, &attr) == NULL) {
            printf("HotspotStaJoin:create task fail!\r\n");
        }
    }
    return;
}

static void OnHotspotStaLeaveHandler(StationInfo *info)
{
    if (info == NULL) {
        printf("HotspotStaLeave:info is null.\r\n");
    } 
    else {
        static char macAddress[32] = {0};
        unsigned char* mac = info->macAddress;
        snprintf(macAddress, sizeof(macAddress), "%02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
        printf("HotspotStaLeave: macAddress=%s, reason=%d.\r\n", macAddress, info->disconnectedReason);
        g_apEnableSuccess--;
    }
    return;
}

static void OnHotspotStateChangedHandler(int state)
{
    printf("HotspotStateChanged:state is %d.\r\n", state);
    if (state == WIFI_HOTSPOT_ACTIVE) {
        printf("wifi hotspot active.\r\n");
    } else {
        printf("wifi hotspot noactive.\r\n");
    }
}

static void Wifi_AP_Demo(void)
{
    osThreadAttr_t attr;

    attr.name = "WifiAPTask";
    attr.attr_bits = 0U;
    attr.cb_mem = NULL;
    attr.cb_size = 0U;
    attr.stack_mem = NULL;
    attr.stack_size = 10240;
    attr.priority = 25;

    if (osThreadNew((osThreadFunc_t)WifiAPTask, NULL, &attr) == NULL)
    {
        printf("Falied to create WifiAPTask!\r\n");
    }
}

APP_FEATURE_INIT(Wifi_AP_Demo);

WIFI STA联网

API

wifi_device.h中包括声明STA联网相关接口函数

STA联网案例

#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include "lwip/netif.h"
#include "lwip/netifapi.h"
#include "lwip/ip4_addr.h"
#include "lwip/api_shell.h"

#include "cmsis_os2.h"
#include "hos_types.h"
#include "wifi_device.h"
#include "wifiiot_errno.h"
#include "ohos_init.h"

#define DEF_TIMEOUT 15
#define ONE_SECOND 1

static void WiFiInit(void);
static void WaitSacnResult(void);
static int WaitConnectResult(void);
static void OnWifiScanStateChangedHandler(int state, int size);
static void OnWifiConnectionChangedHandler(int state, WifiLinkedInfo *info);
static void OnHotspotStaJoinHandler(StationInfo *info);
static void OnHotspotStateChangedHandler(int state);
static void OnHotspotStaLeaveHandler(StationInfo *info);

static int g_staScanSuccess = 0;
static int g_ConnectSuccess = 0;
static int ssid_count = 0;
WifiEvent g_wifiEventHandler = {0};
WifiErrorCode error;

#define SELECT_WLAN_PORT "wlan0"

#define SELECT_WIFI_SSID "BearPi"
#define SELECT_WIFI_PASSWORD "0987654321"
#define SELECT_WIFI_SECURITYTYPE WIFI_SEC_TYPE_PSK

static BOOL WifiSTATask(void)
{
    WifiScanInfo *info = NULL;
    unsigned int size = WIFI_SCAN_HOTSPOT_LIMIT;
    static struct netif *g_lwip_netif = NULL;
    WifiDeviceConfig select_ap_config = {0};

    osDelay(200);
    printf("<--System Init-->\r\n");

    //初始化WIFI
    WiFiInit();

    //使能WIFI
    if (EnableWifi() != WIFI_SUCCESS)
    {
        printf("EnableWifi failed, error = %d\n", error);
        return -1;
    }

    //判断WIFI是否激活
    if (IsWifiActive() == 0)
    {
        printf("Wifi station is not actived.\n");
        return -1;
    }

    //分配空间，保存WiFi信息
    info = malloc(sizeof(WifiScanInfo) * WIFI_SCAN_HOTSPOT_LIMIT);
    if (info == NULL)
    {
        return -1;
    }

    //轮询查找WiFi列表
    do{
        //重置标志位
        ssid_count = 0;
        g_staScanSuccess = 0;

        //开始扫描
        Scan();

        //等待扫描结果
        WaitSacnResult();

        //获取扫描列表
        error = GetScanInfoList(info, &size);

    }while(g_staScanSuccess != 1);

    //打印WiFi列表
    printf("********************\r\n");
    for(uint8_t i = 0; i < ssid_count; i++)
    {
        printf("no:%03d, ssid:%-30s, rssi:%5d\r\n", i+1, info[i].ssid, info[i].rssi/100);
    }
    printf("********************\r\n");

    
    //连接指定的WiFi热点
    for(uint8_t i = 0; i < ssid_count; i++)
    {
        if (strcmp(SELECT_WIFI_SSID, info[i].ssid) == 0)
        {
            int result;

            printf("Select:%3d wireless, Waiting...\r\n", i+1);

            //拷贝要连接的热点信息
            strcpy(select_ap_config.ssid, info[i].ssid);
            strcpy(select_ap_config.preSharedKey, SELECT_WIFI_PASSWORD);
            select_ap_config.securityType = SELECT_WIFI_SECURITYTYPE;

            if (AddDeviceConfig(&select_ap_config, &result) == WIFI_SUCCESS)
            {
                if (ConnectTo(result) == WIFI_SUCCESS && WaitConnectResult() == 1)
                {
                    printf("WiFi connect succeed!\r\n");
                    g_lwip_netif = netifapi_netif_find(SELECT_WLAN_PORT);
                    break;
                }
            }
        }

        if(i == ssid_count-1)
        {
            printf("ERROR: No wifi as expected\r\n");
            while(1) osDelay(100);
        }
    }

    //启动DHCP
    if (g_lwip_netif)
    {
        dhcp_start(g_lwip_netif);
        printf("begain to dhcp");
    }


    //等待DHCP
    for(;;)
    {
        if(dhcp_is_bound(g_lwip_netif) == ERR_OK)
        {
            printf("<-- DHCP state:OK -->\r\n");

            //打印获取到的IP信息
            netifapi_netif_common(g_lwip_netif, dhcp_clients_info_show, NULL);
            break;
        }

        printf("<-- DHCP state:Inprogress -->\r\n");
        osDelay(100);
    }

    //执行其他操作
    for(;;)
    {
        osDelay(100);
    }

}

static void WiFiInit(void)
{
    printf("<--Wifi Init-->\r\n");
    g_wifiEventHandler.OnWifiScanStateChanged = OnWifiScanStateChangedHandler;
    g_wifiEventHandler.OnWifiConnectionChanged = OnWifiConnectionChangedHandler;
    g_wifiEventHandler.OnHotspotStaJoin = OnHotspotStaJoinHandler;
    g_wifiEventHandler.OnHotspotStaLeave = OnHotspotStaLeaveHandler;
    g_wifiEventHandler.OnHotspotStateChanged = OnHotspotStateChangedHandler;
    error = RegisterWifiEvent(&g_wifiEventHandler);
    if (error != WIFI_SUCCESS)
    {
        printf("register wifi event fail!\r\n");
    }
    else
    {
        printf("register wifi event succeed!\r\n");
    }
}

static void OnWifiScanStateChangedHandler(int state, int size)
{
    (void)state;
    if (size > 0)
    {
        ssid_count = size;
        g_staScanSuccess = 1;
    }
    return;
}

static void OnWifiConnectionChangedHandler(int state, WifiLinkedInfo *info)
{
    (void)info;

    if (state > 0)
    {
        g_ConnectSuccess = 1;
        printf("callback function for wifi connect\r\n");
    }
    else
    {
        printf("connect error,please check password\r\n");
    }
    return;
}

static void OnHotspotStaJoinHandler(StationInfo *info)
{
    (void)info;
    printf("STA join AP\n");
    return;
}

static void OnHotspotStaLeaveHandler(StationInfo *info)
{
    (void)info;
    printf("HotspotStaLeave:info is null.\n");
    return;
}

static void OnHotspotStateChangedHandler(int state)
{
    printf("HotspotStateChanged:state is %d.\n", state);
    return;
}

static void WaitSacnResult(void)
{
    int scanTimeout = DEF_TIMEOUT;
    while (scanTimeout > 0)
    {
        sleep(ONE_SECOND);
        scanTimeout--;
        if (g_staScanSuccess == 1)
        {
            printf("WaitSacnResult:wait success[%d]s\n", (DEF_TIMEOUT - scanTimeout));
            break;
        }
    }
    if (scanTimeout <= 0)
    {
        printf("WaitSacnResult:timeout!\n");
    }
}

static int WaitConnectResult(void)
{
    int ConnectTimeout = DEF_TIMEOUT;
    while (ConnectTimeout > 0)
    {
        sleep(1);
        ConnectTimeout--;
        if (g_ConnectSuccess == 1)
        {
            printf("WaitConnectResult:wait success[%d]s\n", (DEF_TIMEOUT - ConnectTimeout));
            break;
        }
    }
    if (ConnectTimeout <= 0)
    {
        printf("WaitConnectResult:timeout!\n");
        return 0;
    }

    return 1;
}

static void WifiClientSTA(void)
{
    osThreadAttr_t attr;

    attr.name = "WifiSTATask";
    attr.attr_bits = 0U;
    attr.cb_mem = NULL;
    attr.cb_size = 0U;
    attr.stack_mem = NULL;
    attr.stack_size = 10240;
    attr.priority = 24;

    if (osThreadNew((osThreadFunc_t)WifiSTATask, NULL, &attr) == NULL)
    {
        printf("Falied to create WifiSTATask!\n");
    }
}

APP_FEATURE_INIT(WifiClientSTA);

UDP客户端

API

socket.h接口简介

socket()

sock_fd = socket(AF_INET, SOCK_STREAM, 0)) //AF_INT:ipv4, SOCK_STREAM:tcp协议

描述：

在网络编程中所需要进行的第一件事情就是创建一个socket，无论是客户端还是服务器端，都需要创建一个socket，该函数返回socket文件描述符，类似于文件描述符。socket是一个结构体，被创建在内核中。

sendto()

int sendto ( socket s , const void * msg, int len, unsigned int flags,
const struct sockaddr * to , int tolen ) ;

描述：

sendto() 用来将数据由指定的socket传给对方主机。参数s为已建好连线的socket。参数msg指向欲连线的数据内容，参数flags 一般设0，

recvfrom()

int recvfrom(int s, void *buf, int len, unsigned int flags, struct sockaddr *from, int *fromlen);

描述：
从指定地址接收UDP数据报。

参数：

UDP客户端案例

#include <stdio.h>
#include <unistd.h>

#include "ohos_init.h"
#include "cmsis_os2.h"

#include "wifi_device.h"
#include "lwip/netifapi.h"
#include "lwip/api_shell.h"
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include "lwip/sockets.h"
#include "wifi_connect.h"

#define _PROT_ 8888

//在sock_fd 进行监听，在 new_fd 接收新的链接
int sock_fd;

int addr_length;
static const char *send_data = "Hello! I'm BearPi-HM_Nano UDP Client!\r\n";

static void UDPClientTask(void)
{
    //服务器的地址信息
    struct sockaddr_in send_addr;
    socklen_t addr_length = sizeof(send_addr);
    char recvBuf[512];

    //连接Wifi
    WifiConnect("TP-LINK_65A8", "0987654321");

    //创建socket
    if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
    {
        perror("create socket failed!\r\n");
        exit(1);
    }

    //初始化预连接的服务端地址
    send_addr.sin_family = AF_INET;
    send_addr.sin_port = htons(_PROT_);
    send_addr.sin_addr.s_addr = inet_addr("192.168.0.175");
    addr_length = sizeof(send_addr);

    //总计发送 count 次数据
    while (1)
    {
        bzero(recvBuf, sizeof(recvBuf));

        //发送数据到服务远端
        sendto(sock_fd, send_data, strlen(send_data), 0, (struct sockaddr *)&send_addr, addr_length);

        //线程休眠一段时间
        sleep(10);

        //接收服务端返回的字符串
        recvfrom(sock_fd, recvBuf, sizeof(recvBuf), 0, (struct sockaddr *)&send_addr, &addr_length);
        printf("%s:%d=>%s\n", inet_ntoa(send_addr.sin_addr), ntohs(send_addr.sin_port), recvBuf);
    }

    //关闭这个 socket
    closesocket(sock_fd);
}

static void UDPClientDemo(void)
{
    osThreadAttr_t attr;

    attr.name = "UDPClientTask";
    attr.attr_bits = 0U;
    attr.cb_mem = NULL;
    attr.cb_size = 0U;
    attr.stack_mem = NULL;
    attr.stack_size = 10240;
    attr.priority = osPriorityNormal;

    if (osThreadNew((osThreadFunc_t)UDPClientTask, NULL, &attr) == NULL)
    {
        printf("[UDPClientDemo] Falied to create UDPClientTask!\n");
    }
}

APP_FEATURE_INIT(UDPClientDemo);