Missing libbsd functions

When looking in various header files in the libbsd package, there are prototypes for various functions but there doesn’t seem to be any source code to go with those functions. Some examples are below:

In the file rtems_bsdnet.h:

All, or nearly all, functions that start with “rtems_bsdnet_”
Are these deprecated? Is the header file itself to be deprecated?

In the file rtems_pppd.h:

rtems_ppp_driver_attach() is declared but not implemented anywhere that I can find.

These are just a few of the items that have me confused as I try to make use of the libbsd package on a new board.

Thanks,
David