[lwip-users] Cannot write to Server using lwIP

[Teckinal Greek]

Hi,

I have successfully implemented Client-Server model using lwIP Raw API, I can connect to my Server which is my PC( a small server program is running so that i can use telnet command to get connected to it from normal PC and can write to it by typing from the key board). In the same way I have made my FPGA to work as client. With my code I can connect it to the server, which i can see on the server side that my client is connected. Now my problem is that I could not write to the server. Here is the piece of code which does the job of writing to the server......

static err_t client_connected(void *arg, struct tcp_pcb *tpcb, err_t err)

{

    char string[] = "Hello!";

    LWIP_UNUSED_ARG(arg);

    err_t ret_val;

    if(err != ERR_OK)

    printf("\n client connected(): err argument not set to ERR_OK, but the value is %d\n", err);

     else

    {

        tcp_sent(tpcb, client_sent);

        printf("Sucess\n");

        ret_val = tcp_write(tpcb, &string, sizeof(string), 1);

        printf("ret_val = %d", ret_val); 

        tcp_output(tpcb);

    }

    return err;

}

I am getting the value of ret_val = 0.

But the problem is that I could not print the string "Hello!" to the server. Where am I making my mistake.

Regards,

TG