[lwip-users] Need help to understand the pbuf_header function????

[Kelly Chan]

The function below shows the pbuf size by moving forward the payload ptr. I
understand we can strip of header by moving backward the payload ptr, I
don;t understand how can we expand the advance the payload ptr to accomdate
the new header. Will the memory corrupt by using this function??? Is it
memory safe?????

/* Make room for Ethernet header. */
if(pbuf_header(p, 14) != 0)
{
  ......
}

Looking forward to any explanation....


Kelly