What is /sbin/ujail? What does it do exactly?


{dnsmasq} /sbin/ujail -t 5 -n dnsmasq -u -l -r (..)
{ntpd} /sbin/ujail -t 5 -n ntpd -U ntp (..)
{wpa_supplicant} /sbin/ujail -t 5 -n wpa_supplicant -U network (..)

Is this the project site https://launchpad.net/ujail ?

ujail is intended to be a system for sandboxing processes in userspace. Its main purpose is to provide security through controlling the syscalls made by a process and possibly emulating some calls. Using this technique ujail provides means to do various security-related things, like creating a syscall-level firewall or containing a process in a single directory, but still allowing selective access to files outside this directory. ujail is being designed to provide a library which can be embedded in other programs.

I not find docs...

The article is quite outdated, but it will give you a general idea.