title: Where is udp header added to data in the kernel code
body: <p>I'm coding a new UDP based protocol in the kernel so I just forked the UDP code to get a head start. I need some new fields in the header struct other than the existing ones. I created a new struct for this but I'm at a loss regarding where this struct is initialized to prepend to the data while sending out a udp frame by the udp_sendmsg function(which I copied from the udp code).</p>
  
  <p>To be clear, I just want to change the header that udp_sendmsg() places before the data. So it should be enough to know where in the kernel code the header and data are combined.</p>
  
  <p>Thank you.</p>