Error after some accept and close (tcpip socket, multiple connections)

[FalkoJahn]

I'm new in the Forum and i want so Hi and a happy new year first
Now my question...


I want to build a wifi to Rs485 modbus konverter. I'm using tcp-ip socket. After i get a connection from a new client i want to close a old connection. This works fine for some time. I can connect from one client, then connect from a another client and it automatically closes the connection from the first client... and so on... but after about 10 times, i get the error 23 at accept().

It looks like this problem https://github.com/espressif/esp-idf/issues/2454
But i have already the latest version from the idf . The changes from f2d3efd in sockets.c are already in the file.
git describe gives me this Version number: v3.3-beta1-220-gdbca85f96


So maybe i do something wrong:

Here my Code

Code: Select all

static void connectionTask(void *arg )
{
	// arg enthält einen Zeiger auf eine Verbindung
	int *temp = (int*) arg;
	int conn = *temp;
    char rx_buffer[256];
    int i;

connectionCount++;

    while (1)
    {

        int len = recv(conn, rx_buffer, sizeof(rx_buffer), 0);
        // Error occured during receiving

        if (len < 0)
        {
            ESP_LOGE(TAG, "recv failed: errno %d", errno);
            break;
        }

        // Connection closed
        else if (len == 0)
        {
            ESP_LOGI(TAG, "Connection closed");
            break;
        }

        // Data received
        else
        {
            rs485_write(rx_buffer,len);
        }
    }

    //Dieser Punkt wird erreicht, wenn die Verbindung beendet wurde, oder ein Fehler aufgetreten ist.

    //Verbindung schließen
    shutdown(conn,2);
    close(conn);
    connectionCount--;

    //Prüfe ob diese Verbindung die letzte noch offene war
    if (connectionCount == 0)
    {
    	//wenn ja, dann link led abschalten
        LED_link_off();
    }


    //suche meinen Task und meine Verbindung in der Liste und setzte Sie auf 0
    for (i = 0; i < MAX_CONNECTIONS; i++)
    {
    	ESP_LOGI(TAG, "Found id %d in list position %d", conn,i);
    	if (connectionlist[i] == conn)
    	{
    		connectionlist[i]  = 0;
    		tasklist[i]  = 0;
    		break;
    	}
    }

    //Task wird beendet
    vTaskDelete(NULL);

}




void tcp_server_task(void *pvParameters)
{


	memset(connectionlist, 0, MAX_CONNECTIONS);
	memset(tasklist, 0, MAX_CONNECTIONS);

    char addr_str[128];

    int addr_family;

    int ip_protocol;

    int listen_sock;

    struct sockaddr_in6 destAddr;

    int res;





#ifdef CONFIG_EXAMPLE_IPV4


	destAddr.sin_addr.s_addr = htonl(INADDR_ANY);

	destAddr.sin_family = AF_INET;

	destAddr.sin_port = htons(PORT);

	addr_family = AF_INET;

	ip_protocol = IPPROTO_IP;

	inet_ntoa_r(destAddr.sin_addr, addr_str, sizeof(addr_str) - 1);

#else // IPV6


	bzero(&destAddr.sin6_addr.un, sizeof(destAddr.sin6_addr.un));

	destAddr.sin6_family = AF_INET6;

	destAddr.sin6_port = htons(CONFIG_rs485Port);

	addr_family = AF_INET6;

	ip_protocol = IPPROTO_IPV6;

	inet6_ntoa_r(destAddr.sin6_addr, addr_str, sizeof(addr_str) - 1);

#endif



	listen_sock = socket(addr_family, SOCK_STREAM, ip_protocol);

	if (listen_sock < 0) {

		ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
		vTaskDelete(NULL);
		return;

	}

	ESP_LOGI(TAG, "Socket created");

	int err = bind(listen_sock, (struct sockaddr *)&destAddr, sizeof(destAddr));

	if (err != 0) {

		ESP_LOGE(TAG, "Socket unable to bind: errno %d", errno);
		vTaskDelete(NULL);
		return;

	}

	ESP_LOGI(TAG, "Socket binded");



	err = listen(listen_sock, 1);

	if (err != 0) {

		ESP_LOGE(TAG, "Error occured during listen: errno %d", errno);
		vTaskDelete(NULL);
		return;

	}

	ESP_LOGI(TAG, "Socket listening");



	struct sockaddr_in6 sourceAddr; // Large enough for both IPv4 or IPv6
    uint addrLen = sizeof(sourceAddr);

	while (1)
	{
        connectionlist[i]  = accept(listen_sock, (struct sockaddr *)&sourceAddr, &addrLen);


        if (connectionlist[i] < 0) {

            ESP_LOGE(TAG, "Unable to accept connection: errno %d", errno);
            continue;

        }

        ESP_LOGI(TAG, "New connection %d accepted, connection %d", connectionlist[i], i );

        //neuen task starten
        tasklist[i] =  sys_thread_new("MODBUS CONNECTIONS TASK", connectionTask,  ( void * ) &connectionlist[i], 2048, 5);
        LED_link_on();


        //nächste Verbindung auf der nächsten Position in der Verbindungslistelegen
        i++;

        ///wenn maximale Verbindungsanzahl erreicht, dann wieder bei 0 anfangen,
        //alte Verbindungen werden dann geschlossen
        if (i >= MAX_CONNECTIONS)
        {
        	i=0;
        }

        //falls auf der Verbindungsliste am Platz i bereits eine alte Verbindung besteht, diese Verbindung beenden und task löschen
        if (connectionlist[i] != 0)
        {
        	ESP_LOGI(TAG, "Close old connection number %d, connection id %d",i, connectionlist[i] );

        	vTaskDelete(tasklist[i]);
            shutdown(connectionlist[i],2);;
        	res = close(connectionlist[i]);
        	if (res != 0)
        	{
        		ESP_LOGE(TAG, "Error closing old connection number %d, connection id %d",i, connectionlist[i] );
        	}



        	connectionlist[i] = 0;
        	tasklist[i] = 0;
        }

	}


    vTaskDelete(NULL);

}