The ef_vi API has been extended to allow users to perform lookups of the Linux routing tables efficiently and with support for many of the advanced features of the Linux networking stack. The implementation of this feature uses the same infrastructure which supports Onload and TCPDirect, but presents an API which is optimised for usage outside of those products.
The documentation for this API can be found in src/include/cplane/api.h, and an example of how one might use this api can be found in the src/tests/ef_vi/efsend_cplane.c example application.