LinuxDriver mixes in ListeningSocketsMixin (napalm-device-types 2.4.0) and
supplies its transport: privileged readings go through _run_privileged --
as they are for a root login, through sudo with a password, sudo -n
without one -- and the rest through _send. The command arrives as one
sh -c argument, so sudo covers the whole script; when sudo refuses, the
mixin reads again without it.
OpenMediaVault and QNAP QTS inherit it; a host without ss raises
ListeningSocketsUnavailable.
For netOrk#658.
Christian Manivong