[Swan-dev] question from IRC: does IKEv1 do auto-fill of NP?

[D. Hugh Redelmeier]

IKEv1 packet.h routines will fill in the next payload field automatically.  
This was done by extending what Andrew had already done for v2.

It is intended for this to be set up correctly but removing the 
pre-computing code might expose flaws.  I don't expect any since the 
automatic code checks that any already-filled-in next payload field 
checks to see that the field is either unfilled or is already 
filled with what it would have used.

This should be visible in the debug output.

One known flaw: in one routine ID payloads are just echoed from the input 
payload into the output payload.  The appropriate packet.h routines for 
payload emission are not called.  The proper next payload values are 
jammed directly into the output buffer.  Ugly, but it seems to work.  I 
haven't taken the time to rework that code.