About LwIP: Socket communication with Localhost (127.0.0.1)

[Hari Kapparapu]

Posted on January 13, 2017 at 19:42

Hello All,

I am working on LwIP application with STM32F429 Nucleo Kit.

I am able to establish the connection and communicate with external client/server without any issues.

But now, I need it to be tested with socket communication within the same board using the same system IP or Localhost using IP address127.0.0.1. I tried with different options (1. starting both threads at same time, 2. starting client thread after kicking the server thread, as shown below) but no success.

Now, I got a fundamental doubt that, is LwIP with FreeRTOS can support with this feature or not. If yes, can someone suggest how to make it work please? A quick response is highly appreciated.

Below is the code snippet I am using for my testing:

Both of these are stuck at bold highlighted lines and timed out after 20seconds. Further debugging through the source code is failed at taking the semaphore at:

     TCPIP_APIMSG(&API_MSG_VAR_REF(msg), lwip_netconn_do_connect, err);

in function

     netconn_connect(struct netconn *conn, const ip_addr_t *addr, u16_t port)

Thank you!

Hari

------------------------------

#define SENDER_PORT_NUM 1000

#define SERVER_PORT_NUM 1000

#define SERVER_IP_ADDRESS '127.0.0.1'

char data_buffer1[80];

char data_buffer2[80];

void OSAL_ServerSocket(void *pvParameters)

{    int _socket_fd;    struct sockaddr_in client;    int clientFd;    socklen_t len = sizeof(client);    BaseType_t taskStatus;        vTaskDelay(1000);    printSerial (PRN_CYAN 'Server Socket - ' PRN_NORMAL 'Enter\n\r');    _socket_fd = lwip_socket(PF_INET, SOCK_STREAM, 0);    if(_socket_fd >= 0)    {        printSerial (PRN_CYAN 'Server Socket - ' PRN_NORMAL 'Server Socket created\n\r');        struct sockaddr_in myaddr;        memset((char*)&myaddr, 0, sizeof(myaddr));        memset(&myaddr, 0, sizeof(struct sockaddr_in));        myaddr.sin_family = AF_INET;        myaddr.sin_port = htons(SENDER_PORT_NUM);        myaddr.sin_addr.s_addr = inet_addr(SERVER_IP_ADDRESS);//htonl(INADDR_ANY);

        //Now bind to the port and listen

        if((lwip_bind(_socket_fd, (struct sockaddr*)&myaddr, sizeof(struct sockaddr)) < 0) ||            (lwip_listen(_socket_fd, 5) < 0))        {            printSerial(PRN_CYAN 'Server Socket - ' PRN_RED 'Error: ' PRN_NORMAL 'Failed to Bind\n\r');            lwip_close(_socket_fd);        }        else        {            printSerial(PRN_CYAN 'Server Socket - ' PRN_NORMAL 'Bind and listening to port (%d)\n\r', SENDER_PORT_NUM);        }    }        taskStatus = xTaskCreate (OSAL_ClientSocket, 'OSAL LWIP Client', configMINIMAL_STACK_SIZE*2, (void*)NULL, osPriorityNormal+1, NULL);    if (pdPASS == taskStatus) {    printSerial(PRN_NORMAL '[' PRN_GREEN ' ok ' PRN_NORMAL '] Task - 'OSAL LWIP Client' created\n\r');  }    else                      {    printSerial(PRN_NORMAL '[' PRN_RED   'fail' PRN_NORMAL '] Task - 'OSAL LWIP Client' created\n\r');  }

    while(1)

    {        printSerial(PRN_CYAN 'Server Socket - ' PRN_NORMAL 'Before accept\n\r');         clientFd = lwip_accept(_socket_fd, (struct sockaddr*)&client, &len); /////////////////////////////////        printSerial(PRN_CYAN 'Server Socket - ' PRN_NORMAL 'After accept\n\r');        if(clientFd < 0)        {            printSerial(PRN_CYAN 'Server Socket - ' PRN_RED 'Error: ' PRN_NORMAL 'accept failed\n');            lwip_close(_socket_fd);        }        else        {            printSerial(PRN_CYAN 'Server Socket - ' PRN_NORMAL 'accepted the request\n\r');            break;        }    }

    while(1)

    {        printSerial(PRN_CYAN 'Server Socket - ' PRN_NORMAL 'Waiting at Server Loop\r');        vTaskDelay(1000);     }}

void OSAL_ClientSocket(void *pvParameters)

{    printSerial(PRN_MAGENTA 'Client Socket - ' PRN_NORMAL 'Enter\n\r');    vTaskDelay(2000);    struct sockaddr_in server;

    printSerial(PRN_MAGENTA 'Client Socket - ' PRN_NORMAL 'Before Create\n\r');

    int sock_client_fd = lwip_socket(PF_INET, SOCK_STREAM, 0);    if(sock_client_fd < 0)    {        printSerial(PRN_MAGENTA 'Client Socket - ' PRN_RED 'Error: ' PRN_NORMAL 'SocketCreation\n\r');    }    {        printSerial(PRN_MAGENTA 'Client Socket - ' PRN_NORMAL 'Created\n\r');    }

    memset((char*)&server, 0, sizeof(server));

    server.sin_family = AF_INET;    server.sin_addr.s_addr = inet_addr(SERVER_IP_ADDRESS);    if (server.sin_addr.s_addr == INADDR_NONE)    {        //Couldnt translate the ip.. return failure        printSerial(PRN_MAGENTA 'Client Socket - ' PRN_RED 'Error: ' PRN_NORMAL 'IP Translation: ');    }    server.sin_port = htons(SERVER_PORT_NUM);    printSerial(PRN_MAGENTA 'Client Socket - ' PRN_NORMAL 'Before Connect\n\r');    if(lwip_connect(sock_client_fd, (struct sockaddr*)&server, sizeof(server)) < 0) ////////////////////////////////////////////    {        printSerial(PRN_MAGENTA 'Client Socket - ' PRN_RED 'Error: ' PRN_NORMAL 'Connect\n\r');    }    else    {        printSerial(PRN_MAGENTA 'Client Socket - ' PRN_NORMAL 'Connected\n\r');        while(1)        {            printSerial(PRN_MAGENTA 'Client Socket - ' PRN_NORMAL 'Waiting at Client Loop\n\r');            vTaskDelay(1000);         }    }        while(1)    {        vTaskDelay(100);    }}

[Hari Kapparapu]

Posted on January 13, 2017 at 19:49

Just to add to the question: The response with timeout I received was 'Connection aborted.' - ERR_ABRT.