[lwip-users] Problem trying to recieve an UDP packet

[Víctor Mateo]

Hi all

 

I´m stuck trying to recieve an UDP packet from a host (192.168.10.10) to a LWIP on 192.168.10.11 and send it back to the host as a simple echo.

I'm sending the UDP packet (a simple character or string) trough port 31 from a C# Console I've programmed and checked that it actually sends right.

 

This are the functions I'm using in the NIOS II IDE enviroment:

 

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void udp_echo_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port)
{
 struct ip_addr adr;
 IP4_ADDR(&adr, 192, 168, 10, 11);
 udp_connect(pcb, &adr,  31);
 //udp_send(pcb, p);
    
    
   if (p != NULL) {
    /* FIXME: possibly use udp_connect() and udp_disconnect()
                  instead of manipulating the pcb directly */
        pcb->remote_ip = *addr;
        pcb->remote_port = port;
        udp_send(pcb, p);
        /* FIXME: udp_disconnect() ? */
    }
    /* free the pbuf */
    pbuf_free(p);
    printf("udp_echo OK!\n");
}

void udp_echo_init(void)
{
      struct ip_addr adr;
//    IP4_ADDR(&adr, 192, 168, 10, 10);
//    udp_connect(pcb, &adr,  31);
//    udp_send(pcb, p);
    udp_remove(pcb); //Elimino el pcb anterior (el de transmision)  
    err_t retval;
    struct udp_pcb * pcb; 

    pcb = udp_new();
    if (pcb == NULL) printf("udp_new failed!\n");

    retval = udp_bind(pcb, IP_ADDR_ANY, 31);
    //retval = udp_bind(pcb, IP_ADDR_ANY, 31);
    if (retval != ERR_OK) printf("udp_bind failed!\n");
    IP4_ADDR(&adr, 192, 168, 10, 11);
    udp_connect(pcb, &adr,  31);
    //udp_bind(pcb, IP_ADDR_ANY, 31);
    
    udp_recv(pcb, udp_echo_recv, NULL );
    
    printf("udp_rcv OK!\n");
    //udp_disconnect(pcb);  
}
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and I call udd_echo_init() from the main.c as an infinite listen circle:
 
-------------------------------
while(1)
{
udp_echo_init();
}
-------------------------------
 
NIOS II compiles and runs the program fine, the message "udp_recv OK" is shown but "udp_echo OK" doesn't. I don't know but it seems that udp_echo_recv() is not working.
Can anybody help me with this?
 
Thank you

--

Víctor Mateo Gómez