My linux application port is taken by another service when it's stopped

Question

I developed an application which contains a small http server.

my application is launched in the boot. If I kill it (with kill -9 for example), the http server port will be taken directly by another daemon(acsd from broadcom).

I tried the same behavior with drop-bear, but the problem is not reproduced. If I kill drop-bear the acsd does not take its port.

here after the code of my server:

void http_server_init(void)
{
    struct sockaddr_in server;
    int cr_port;

    for(;;) {
        cr_port = conf.port;
        int i = (DEFAULT_PORT == cr_port)? 1 : 0;
        //Create socket
        cr_socket_desc = socket(AF_INET , SOCK_STREAM , 0);
        if (cr_socket_desc == -1)
        {
            LOG (ERROR,"Could not open server socket, Error no is : %d, Error description is : %s", errno, strerror(errno));
            sleep(1);
            continue;
        }

        /* enable SO_REUSEADDR */
        int reusaddr = 1;
        if (setsockopt(cr_socket_desc, SOL_SOCKET, SO_REUSEADDR, &reusaddr, sizeof(int)) < 0) {
            LOG (WARNING,"setsockopt(SO_REUSEADDR) failed");
        }

        //Prepare the sockaddr_in structure
        server.sin_family = AF_INET;
        server.sin_addr.s_addr = INADDR_ANY;
        for(;;i++) {
            server.sin_port = htons(cr_port);
            //Bind
            if( bind(cr_socket_desc,(struct sockaddr *)&server , sizeof(server)) < 0)
            {
                //print the error message
                LOG (ERROR,"Could not bind server socket on the port %d, Error no is : %d, Error description is : %s", cr_port, errno, strerror(errno));
                cr_port = DEFAULT_PORT + i;
                LOG (INFO,"Trying to use another port: %d", cr_port);
                continue;
            }
            break;
        }
        break;
    }
    LOG (INFO,"server initiated with the port: %d", cr_port);
}

What I'm doing wrong in my http server?

Answer 1

since I don't have response for my question. I would like to share with you the response for that problem.

The acsd service take the port because the socket is not closed and the option SO_REUSEADDR is set