Re: [lwip-users] lwip udp server

[Çağlar AKYÜZ]

Andrea Visinoni wrote:
> Hi all,
Hi,
> i'm trying to develop an udp server over an AT91SAM7X-EK board, and 
> i've some problems.
> First of all, tcp is working correctly, and if i ping my board it 
> replys, i've already done a tcp server and it works.
> Is there an example about udp server or udp usage?
> Thanks
> Andrea
Here is my working UDP server on SAM7X(on a FREERTOS port). After 
bringing up a mac interface you can init connection. In this example, 
only connections from a predefined IP address is accepted. This is not 
neccessary.

Regards
Caglar AKYUZ

void init()
{
   /* create a new UDP connection */
    listen_pc = netconn_new( NETCONN_UDP );
    
    /* set up the IP address of the remote host. This is one is 
192.168.2.7.
     * this is not that much neccessary.
     */    
   addr.addr = htonl(( 192 << 24 )  | ( 168 << 16 )  | ( 100 << 8 ) | ( 
7 << 0 ));
   
   /* connect the connection to the remote host */    
   netconn_connect(listen_pc, &addr, 15000 );
   
   /* Make datagram_recved callback function and bind to the local port
    * When there is a packet recved from the network our datagram_recved
    * function will be called.
    */        
   udp_recv( listen_pc->pcb.udp, datagram_recved, NULL );
   netconn_bind( listen_pc , NULL , 33333 );        
   
   /* create a new netbuf. This buffer is for referencing ethernet data. */
   buf = netbuf_new();
   /* Reference the request data into net_buf */
   netbuf_ref( buf , (int *)some_data_pointer , 
some_data_length_in_bytes );
  /* Then send the datagram */        
   netconn_send( listen_pc , buf );
}

void datagram_recved(void *arg, struct udp_pcb *pcb, struct pbuf *p, 
struct ip_addr *addr, u16_t port)
{
   
   /* Supress compiler warnings */
   ( void ) arg;
   ( void ) addr;
   ( void ) port;   
  
   /* Do something with the pbuf */
  
   /* Don't forget to free buffer */       
   pbuf_free(p);   
}