蓝牙插座未收到数据包

Question

过去 10 天我一直在研究蓝牙插座。我必须在客户端和服务器模式之间切换。我写了一段代码。我能够很好地发送数据包，但是当我在监听模式下工作时，我遇到了两个问题。 1.接受处于块模式，因此无法返回发送模式。 2.我使用 FNCTL() 将套接字设置为非阻塞，

但现在问题来了，即在两种模式之间完美切换，但它没有接收任何数据包。我的代码如下：-

#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include <bluetooth/l2cap.h>
#define MAXPROFILES  2


int SetTimer(struct timeval *tv, time_t sec)
{
    gettimeofday(tv,NULL);
    tv->tv_sec+=sec;
    return 1;
}

void start_scan()
{   
    struct sockaddr_l2 addr1 = { 0 };
    int s=0,h, status,f,contacted;
    int search=1;
    char *message = "hello!";
    char dest[18] = "01:23:45:67:89:AB";
    struct neighbor
    {
    char peer[19];
    }   p[h];

    unsigned char buf[1024];
    inquiry_info *devices = NULL;
    int max_rsp, num_rsp;
    int dev_id, sock, len, flags,cmp;
    int x=0,i;
    char addr[19] = { 0 };
    char name[248] = { 0 };


    dev_id = hci_get_route(NULL);
    sock = hci_open_dev( dev_id );
    if (dev_id < 0 || sock < 0) 
    {
        perror("opening socket");
        exit(1);
    }


    len  = 3;
    max_rsp = 255;
    flags = IREQ_CACHE_FLUSH;
    devices = (inquiry_info*)malloc(max_rsp * sizeof(inquiry_info));
    struct timeval tv;
    SetTimer(&tv,15);
    while(search == 1)
    {   //fprintf(stderr,"\t%d \n", time);
        num_rsp = hci_inquiry(dev_id, len, max_rsp, NULL, &devices, flags);
        fprintf(stderr,"%s (%d) %d\n", "done scanning, found ", j, num_rsp);
        if( num_rsp < 0 ) perror("hci_inquiry");

        for (i = 0; i < num_rsp; i++)
        {
        ba2str(&(devices+i)->bdaddr, addr);
        fprintf(stderr,"\t%s \n", addr);
        cmp= strncmp(addr,"10:2E:AF:EB:33:BD",8);
        if(cmp==0)
        {
         fprintf(stderr,"\t%s \t%d\n", addr,cmp);
            for(f=0;f<=h;f++)
            {
                if(p[f].peer[18]==addr[19])
                contacted=1;
            }
                if(contacted==1)
                {
                contacted=0;
                continue;
                }

            s = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);

            // set the connection parameters (who to connect to)
            addr1.l2_family = AF_BLUETOOTH;
            addr1.l2_psm = htobs(0x1001);
            strncpy(dest, addr, 18);

            str2ba( dest, &addr1.l2_bdaddr );

// connect to server
            status = connect(s, (struct sockaddr *)&addr1, sizeof(addr1));

// send a message
            if( status == 0 )
            {

            status = write(s, "hello", 10);
            h++;
            p[h].peer[18]=addr[19];

            }

            if( status < 0 )
            {
            perror("uh oh");
            }
        }
      }  // for
     x++;
     if(!(x%2))
        flags = IREQ_CACHE_FLUSH;
     else
        flags = 0x00;
    if (CheckTimer(&tv,5)==1)
        {   //close(sock);
            fprintf(stderr,"listen....\n");



        start_listen(s);
        }
    }
}
    int start_listen(int s)     
    { struct sockaddr_l2 addr1 = { 0 },rem_addr = { 0 };;
     fd_set fds;
    int client, bytes_read,sock_flags;
    char buf1[1024] = {0};
    socklen_t opt = sizeof(rem_addr);
    struct timeval tv;


    addr1.l2_family = AF_BLUETOOTH;
    addr1.l2_bdaddr = *BDADDR_ANY;
    addr1.l2_psm = htobs(0x1001);
    sock_flags=fcntl(s,F_GETFL,0);
    fcntl(s,F_SETFL,sock_flags | O_NONBLOCK);
    bind(s, (struct sockaddr *)&addr1, sizeof(addr1));
    SetTimer(&tv,15);
    // put socket into listening mode
    while(!0)
        {
                listen(s, 1);
                //fprintf(stderr,"I am listening....\n");


    // accept one connection
                client = accept(s, (struct sockaddr *)&rem_addr, &opt);
                //fprintf(stderr,"I failed....\n");
                FD_ZERO(&fds);
                FD_SET(s,&fds);             
                ba2str( &rem_addr.l2_bdaddr, buf1 );

                memset(buf1, 0, sizeof(buf1));

    // read data from the client
                bytes_read = read(client, buf1, sizeof(buf1));
                    if( bytes_read > 0 ){
                        printf("received [%s]\n", buf1);
                    fprintf(stderr, "accepted connection from %s\n", buf1);
                    }
                close(client);

                    if (CheckTimer(&tv,5)==1)
                        {fprintf(stderr,"done listening...");

                        SetTimer(&tv,15);
                        return 1;
                        }
            }//while of the listening mode

} 


int CheckTimer(struct timeval *tv, time_t sec)
{
    struct timeval ctv;
    gettimeofday(&ctv,NULL);
    if((ctv.tv_sec > tv->tv_sec))
    {   
        gettimeofday(tv,NULL);
        tv->tv_sec+=sec;
        return 1;
    }
    else return 0;
}

int main(int argc, char **argv)
{start_scan();
}

Answer 1

在绑定之前，我可以通过在侦听模式下再次输入以下命令来解决该问题。

s = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);

但现在的问题是我的 close(client) 不起作用。我无法关闭客户端并收听新客户端。有谁知道为什么？

Answer 2

根本不需要打开服务器套接字！ （除非您的远程设备正在做一些非常奇怪的事情！！）套接字可用于发送和接收-- 无论是客户端套接字还是服务器套接字。

删除所有执行侦听+接受等操作的代码，然后写入和读取原始（客户端）套接字。（使用以下代码完成的代码：“connect(s,...”）

如果您的远程设备确实需要使用一个新变量来保存套接字句柄，并且不要让服务器套接字句柄覆盖原始客户端句柄。