mipext-advapi-04: sending HAO

Hi,

Quoting section 3:

   For sending Home Address destination option, ancillary data can be 
   used to specify the option content for a single datagram. This
   only applies to datagram and raw sockets; not to TCP sockets.
   Advanced API [1] document restricts one IPV6_xxx ancillary data
   object for a particular extension header in the control buffer.
   Thus there would be a single ancillary data object for Home address
   destination option in a ancillary data buffer. If the kernel
   implementation supports this API, it is responsible for extracting
   the Home address destination option data object and placing it as
   destination option extension header in compliance with section
   6.3 of Mobile IPv6 [2] base specification.

I believe there is one assumption that should be explicitly written - when 
a system supports mip advanced api, then the kernel is in charge of swapping source
address and HAO content before sending the packet.

I would like to be sure that my MIP6 application behaves the same across all 
systems,
which sets HoA as source address and care-of address as HAO before the call to 
sendmsg().

Regards,

Jean-Mickael