SCTP multihoming: Source address selection based on destination route entry

[sriramy]

Hi,

When a SCTP association has multiple local and remote addresses, it would be nice if usrsctplib picks source address based on the outgoing interface the packet is configured to be sent on. Today, it looks like the first address with the correct scope is used, but that can lead to problems if the chosen source address is not routable back on the interface.

If I understand correctly, I am looking to fix this TODO: https://github.com/sctplab/usrsctp/blob/master/usrsctplib/netinet/sctp_os_userspace.h#L863.
I can contribute if this is not being worked on by someone already.

BR,
/Sriram