bectl: use jail id as the default jail name for a boot environment
By default, bectl is setting the jail 'name' parameter to the boot
environment name, which causes an error when the boot environment name is
not a valid jail name. With the attached fix, when no name is supplied, the
default jail name will be the jail id - this is is the same behavior as the
jail command.
Additionally, this commit addresses two other bugs that prevented unjailing
in scenarios where the jail name does not match the boot environment name:
- In 'bectl_locate_jail', 'mountpoint' is used to resolve the boot environment path, but really 'mounted' should be used. 'mountpoint' is the path where the zfs dataset will be mounted. 'mounted' is the path where the dataset is actually mounted.
- in 'bectl_search_jail_paths', 'jail_getv' would fail after the first call. Which is fine, if the boot environment you're unjailing is the next one up. According to 'man jail_getv', it's expecting name and value strings. 'jail_getv' is being passed an integer for the lastjid, so amend that to use a string instead.
Test cases have been amended to reflect the bugs found.
PR: 233637
Submitted by: Rob <rob.fx907_gmail.com>
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D18607