关于smartconfig的研究

Posted 2020-11-18 roysphoneblog

           smartconfig 实际就是 手机端发送多播一串经过处理的数据，然后接收端，接受到这个数据之后，解析到wifi密码，连接上wifi,在实现过程中可能遇到的问题如下：

           1.  send socket的设置 

          

 SOCKET sendSock = socket(AF_INET,SOCK_DGRAM,0);
    if (sendSock == INVALID_SOCKET)
    {
        printf("socket error
");
        return -1;
    }
    int n = 1;
    ret = setsockopt(sendSock, IPPROTO_IP, IP_MULTICAST_TTL, (char*)&n, sizeof(n));
    if (0 != ret)
    {
        printf("setsockopt error
");
        return -1;
    }

 

需要将sock设置为广播模式,在 将数据组装以后，发送数据时：

 ssize_t ret = sendto(sendSock, buf, strlen(buf) + 1, 0, (sockaddr*)&addr, sizeof(sockaddr));
                if (ret == SOCKET_ERROR)
                {
                    printf("sendto error!
");
                }

其中地址，为你多播的地址，不同的协议发送的地址，不一样，看你的芯片。

 

           2.  手机接受返回数据如下:

           

  SOCKET recvSock = socket(AF_INET, SOCK_DGRAM, 0);
    if (INVALID_SOCKET == recvSock)
    {
        printf("socket error
");
        return -1;
    }
    
    sockaddr_in recvAddr;
    recvAddr.sin_family = AF_INET;
    recvAddr.sin_addr.s_addr = INADDR_ANY;
    recvAddr.sin_port = htons(8068);
    
    int ret = bind(recvSock, (sockaddr*)&recvAddr, sizeof(recvAddr));
    if (ret != 0)
    {
        printf("bind error
");
        return -1;
    }
    
    // o”???è≤??≤
    ip_mreq multiCast;
    multiCast.imr_interface.s_addr = INADDR_ANY;
    multiCast.imr_multiaddr.s_addr = inet_addr("236.236.238.50");
    ret = setsockopt(recvSock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&multiCast, sizeof(multiCast));
    if (0 != ret)
    {
        printf("setsockopt error
");
        return -1;
    }

socket的创建；

socket接受时的处理:

 do
    {
        timeout.tv_sec=0;
        timeout.tv_usec=500000;
        
        FD_ZERO(&readset);
        FD_SET(recvSock,&readset);
        int result=select(recvSock+1,&readset,NULL,NULL,&timeout);
        printf("the result is %d
",result);
        
        if(FD_ISSET(recvSock,&readset)>0)
        {
            socklen_t len = sizeof(sockaddr);
            
            char buf[100] = {0};
            printf("start recv
");
            ssize_t ret = recvfrom(recvSock, buf, sizeof(buf) - 1, 0, (sockaddr*)&recvAddr, &len);
            
            if (ret == SOCKET_ERROR)
            {
                printf("recvfrom error!
");
                return -1;
            }
            printf("recv len is %d
,the data is %s
 the strlen is %ld",len,buf,strlen(buf));
　　//处理数据
            }while(1)