Receiving UDP data from Arduino

When any packet is received it is keep in burref.

So after function who read pakets we need to check is packet received is UDP.

Some information:

IP_PROTO_P = HEX 0x17 (DEC 23)

IP_PROTO_UDP_V =  HEX 0x11 (DEC 17)

We must check if in buffer possition 23 we have 17

Code:

    // read packet, handle ping and wait for a tcp packet:
    dat_p=es.ES_packetloop_icmp_tcp(buf,es.ES_enc28j60PacketReceive(BUFFER_SIZE, buf));
    
  
    if (buf[IP_PROTO_P]==IP_PROTO_UDP_V){   // ==     if (buf[23]==17)

     // We have UDP paket received

   }

Exsample UDP packet, buffer positions and values: