Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC 256385:

- Add mount.fdescfs parameter to jail(8). This is similar to
mount.devfs but mounts fdescfs. The mount happens just after
mount.devfs.

- rc.d/jail now displays whole error message from jail(8) when a jail
fails to start.

Approved by: re (gjb)

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Reverse the order of some implicit commands (FS mounts and ifconfigs)
when stopping jails. This matters particularly for nested filesystem
mounts.

PR: kern/177325
Submitted by: Harald Schmalzbauer
MFC after: 3 days

When writing the jid via the -i flag, do it right when the jail is created,
before any commands run. /etc/rc.d/jail depends on this.

Fix world after byacc import:
- old yacc(1) use to magicially append stdlib.h, while new one don't
- new yacc(1) do declare yyparse by itself, fix redundant declaration of
'yyparse'

Approved by: des (mentor)

Add a meta-parameter IP__NULL to enum intparam, instead of mixing
enum values and zeroes. This keeps clang happy (and is just good form).

Submitted by: dim

A new jail(8) with a configuration file, ultimately to replace the work
currently done by /etc/rc.d/jail.

MFC after: 3 months

Use the defvs_ruleset paramater when mounting a jail's /dev,
instead of a mount.devfs.ruleset pseudo-parameter.

Improvements in error messages:

Some errors printed the jail name for unnamed (command line) jails.

Attempting to create an already-existing jail from the command line
returned with no error (even for non-root) due to bad logic in
start_state.

Ignore kvm_proc errors, which are typically caused by permission
problems. Instead, stop ignoring permission errors when removing
a jail (but continue to silently ignore other errors, i.e. the
jail no longer existing). This makes non-root attempts at removing
a jail give a clearer error message.

Following r222465:

Check for IPv4 or IPv6 to be available by the kernel to not
provoke errors trying to query options not available.
Make it possible to compile out INET or INET6 only parts.

Move the actual create/remove (IP__OP) handling into run_command,
and the cost of an ugly single-use global variable.

Update copyright dates and other whitespacey stuff.

Split run_command up into an outer function (next_command) that chooses
a single command string to run, and an inner function (run_command) that
runs that single string.
Move the list of start/stop commands to run from a switch statement into
an array, with a new placeholder parameter IP__OP for actually creating
or removing the jail.
When jail creation fails, revert all non-exec commands in reverse order.

Change cfstrings from an STAILQ into a TAILQ to allow commands to be
traversed in reverse order.

run_command (mostly) cleanup:

Make the parallelism limit a global instead of always passing it
to run_command and finish_command.
In the case of an empty command string, try to run any other strings
the command may have.
Replace JF_BACKGROUND with its sort-of opposite JF_SLEEPQ.
Change j->comstring earlier to render JF_RUNQ unncessary.
Change the if-else series to a more readable switch statement.
Treat IP_STOP_TIMEOUT like a command, calling run_command which then
calls term_procs.
When the IP_STOP_TIMEOUT "command" finishes, it shouldn't mess with
the parallelism limit.
Make sufficient checks in finish_command and run_command so that
the nonintuitive j->comstring null check isn't necessary to run them.
Rename the "waiting" queue to "depend", because the "sleeping" and
"runnable" queues are also used to wait for something.

Reads the mount.fstab file, and put its lines separately into the
IP__MOUNT_FROM_FSTAB internal parameter.

Combine check_intparams() and ip_params(), JF_CHECKINT and JF_IPPARAMS.

Keep all internal/known parameter names in one place, and use
enum constants everywhere else.

Initial work on the new jail(8). There are more features to add, and some
cleaning up to do on existing features, but this is pretty much what the
final product will look like.