This implements part of RFC-2217
It's based off a patch originally written by Sujal Patel at Isilon, and
contributions from other Isilon employees.
PR: 173728
Phabric: D995
Reviewed by: markj, markm
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division
git-svn-id: http://svn0.us-east.freebsd.org/base/head/contrib/telnet@274364 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
