[lwip-users] Sending UDP

[Julian Gardner [RSD]]

I am sending data via UDP, but for every block of data i send which is 1324 bytes i do the following

  while( bytesToSend)
  {
    newBuf = pbuf_alloc( PBUF_TRANSPORT, 1324, PBUF_RAM);
    memcpy( newBuf->payload, currentBufferPointer, 1324);
    udp_send( outUdp, newBuf);
    pbuf_free( newBuf);
    currentBufferPointer += 1324;
    bytesToSend -= 1324;
  }

if i do the allocate outside of the send loop and the delete after sending all , my code fails!

  newBuf = pbuf_alloc( PBUF_TRANSPORT, 1324, PBUF_RAM);
  while( bytesToSend)
  {
    memcpy( newBuf->payload, currentBufferPointer, 1324);
    udp_send( outUdp, newBuf);
    currentBufferPointer += 1324;
    bytesToSend -= 1324;
  }
  pbuf_free( newBuf);

Also i have to copy the data from its original place to the newBuf->payload every time

What is the best way, pbuf_chain to do the same but just point the newBuf->payload at the data without copying it!!

eg
  newBuf = pbuf_alloc( PBUF_TRANSPORT, 1324, PBUF_RAM);
  while( bytesToSend)
  {
    newBuf->payload = currentBufferPointer;
    udp_send( outUdp, newBuf);
    currentBufferPointer += 1324;
    bytesToSend -= 1324;
  }
  pbuf_free( newBuf);

joolz