MFCr340141:

MFCr340141:
  libcasper: fix limitations in dns service

  The getaddrinfo(3) and gethostbyname(3) are used to return the address for a
  given hostname. The getnameinfo(3) and gethostbyaddr(3) are used to return
  hostname for a given address. Right now in casper, we have two limitations:
  - NAME which allows resolving DNS names.
  - ADDR which allows to do revert DNS lookups.

  Before this change the rights was mixed up:
  NAME - getnameinfo(3) and gethostbyname(3)
  ADDR - gethostbyaddr(3) and getaddrinfo(3)

  Which no matters on limitation allowed us to resolve DNS names and do DNS
  lookups basically by using a different set of functions.

  Now the NAME type allows getaddrinfo(3) and gethostbyname (3)functions,
  and the ADDR names allow to use gethostbyaddr(3) and getnameinfo(3) functions.

  Reviewed by:  pjd, bcr
  Discussed with:       hrs
  Differential Revision:        https://reviews.freebsd.org/D16930