sal socket 不能接收UDP广播包

发布于 2021-06-09 14:07:51 浏览：1028 订阅该版

相关组件：sal
bug说明：sal socket 不能接收广播包，而将sal socket全部替换lwip自带socket 正常接收
lwip 版本：2.0.2
lwip 配置： rthread studio生成的默认配置
sal 使用协议：AF_INET
rtthread版本：3.1.4
MAC+PHY   :  STM32F407VG + DP83848

代码片段：

```c
static char khons_get_ip[32]; 
void ota_find_thread(void*p)
{
    int str_len;
    unsigned int addr_len = sizeof(struct sockaddr_in);
    int receiver_socket;
    struct sockaddr_in receiver_addr;
    int optval = 1;

//初始化receiver_socket
    memset(&receiver_addr,0,sizeof(receiver_addr));
    receiver_addr.sin_family = AF_INET;
    receiver_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    receiver_addr.sin_port = htons(6667);
    memset(&(receiver_addr.sin_zero),0,8);
    
    
    while(1)
    {
        receiver_socket = sal_socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
        
        sal_setsockopt(receiver_socket,SOL_SOCKET,SO_BROADCAST,
            ( void *)&optval,sizeof(optval));
            
        if(receiver_socket < 0)
        {
            rt_thread_mdelay(1000);
            continue;
        }
        
        if(sal_bind(receiver_socket,(struct sockaddr *)&receiver_addr,
            sizeof(struct sockaddr_in)) == -1)
        {
            LOG_E("UDP bind error!");
            sal_closesocket(receiver_socket);
            continue;
        }
        
        while(1)
        {
        
            str_len = sal_recvfrom(receiver_socket,khons_get_ip,30,0,
                (struct sockaddr *)&receiver_addr, &addr_len);
                
            if(str_len < 0)
            {
                LOG_E("UDP bind error!");
                sal_closesocket(receiver_socket);
                break;
            }
            
            khons_get_ip[str_len] = 0;
            LOG_I("broadcast receive:%s",khons_get_ip);
            
            if( sal_sendto(receiver_socket, khons_get_ip, str_len, 0,
                (struct sockaddr*)&receiver_addr, addr_len) < 0)
            {
                LOG_E("udp send msg error: %s(errno: %d)\n", 
                    strerror(errno), errno);
                sal_closesocket(receiver_socket);
                break;
            }

}
    }

}
```

将上述代码中的sal socket函数全部换成lwip socket 函数，则能够正常接收数据包。