MFC jail: fix jail(8) synposis and usage message to match reality.

Reported by: yuri
PR: 254741
MFC after: 5 days

(cherry picked from commit 8c1d956ffa0355ece3b63ea8587938176f87f072)

Git Hash: 73b04801b3163417cff33b279f1bc42451f20009
Git Author: jamie@FreeBSD.org

MFC r360040: jail(8): improve manual and usage information
with more clear description for "jail -e" mode
to show that it does not take additional jail name argument.

Reported by: David Marec <david.marec@davenulle.org>

MFC r340319: jail(8): introduce new command option -e to exhibit
a list of configured non-wildcard jails with their parameters,
no matter running or not.

The option -e takes separator argument that is used
to separate printed parameters. It will be used with following
additions to system periodic scripts to differentiate parts
of directory tree belonging jails as opposed to host's.

MFC r337867:

Don't let clobber jailparam values when checking for modification of
init-only parameters.

PR: 230487
Submitted by: Jason Mader

MFC r326276:

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

MFC r310614: Don't assign rtjp twice.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Add mount.procfs jail parameter, so procfs can be mounted when a prison's
root is in its fstab.

Also fix a typo while I'm at it.

PR: 197237 197066
MFC after: 3 days

In preparation for using clang's -Wcast-qual:

Use __DECONST (instead of my own attempted re-invention) for the iov
parameters to jail_get/set(2). Similarly remove the decost-ish hack
from execvp's argv, except the __DECONST is only added at very end.

While I'm at it, remove an unused variable and fix a comment typo.

- 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)

- Update rc.d/jail to use a jail(8) configuration file instead of
command line options. The "jail_<jname>_*" rc.conf(5) variables for
per-jail configuration are automatically converted to
/var/run/jail.<jname>.conf before the jail(8) utility is invoked.
This is transparently backward compatible.

- Fix a minor bug in jail(8) which prevented it from returning false
when jail -r failed.

Approved by: re (glebius)

Pre-separate IP addresses passed on the command line, so they can be
properly parsed for interface prefixes and netmask suffixes. This was
already done for the old-style (fixed) command line, but missed for
the new-style.

MFC after: 1 week

o Restore -u <username> getopt(3) flag somehow killed in r234712.

PR: bin/169490
Submitted by: amdmi3
MFC after: 2 weeks

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.

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

Try resolving jail path with realpath(3).

jail(8) does a chdir(2) to the given path argument. Kernel evaluates the
jail path from the new cwd and not from the original cwd, which leads to
undesired behavior if given a relative path.

Reviewed by: jamie
MFC after: 2 weeks

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.

Reviewed by: jamie
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
MFC after: 10 days

Change the current working directory to be inside the jail created by
the jail(8) command. [10:04]

Fix a one-NUL-byte buffer overflow in libopie. [10:05]

Correctly sanity-check a buffer length in nfs mount. [10:06]

Approved by: so (cperciva)
Approved by: re (kensmith)
Security: FreeBSD-SA-10:04.jail
Security: FreeBSD-SA-10:05.opie
Security: FreeBSD-SA-10:06.nfsclient

Handle kernels that don't have IPv6 by not sending an "ip6.addr"
parameter unless a (numeric) IPv6 address is given. Even the default
binaries built with -DINET6 will work with IPv6-less kernels. With an
eye to the future, similarly handle the possibility of an IPv4-less kernel.

Approved by: re (kib), bz (mentor)

Add libjail, a (somewhat) simpler interface to the jail_set and jail_get
system calls and the security.jail.param sysctls.

Approved by: bz (mentor)

Remove obsolete comment describing how the command line is
no longer parsed.

Approved by: bz (mentor)

In preparation for raising NGROUPS and NGROUPS_MAX, change base
system callers of getgroups(), getgrouplist(), and setgroups() to
allocate buffers dynamically. Specifically, allocate a buffer of size
sysconf(_SC_NGROUPS_MAX)+1 (+2 in a few cases to allow for overflow).

This (or similar gymnastics) is required for the code to actually follow
the POSIX.1-2008 specification where {NGROUPS_MAX} may differ at runtime
and where getgroups may return {NGROUPS_MAX}+1 results on systems like
FreeBSD which include the primary group.

In id(1), don't pointlessly add the primary group to the list of all
groups, it is always the first result from getgroups(). In principle
the old code was more portable, but this was only done in one of the two
places where getgroups() was called to the overall effect was pointless.

Document the actual POSIX requirements in the getgroups(2) and
setgroups(2) manpages. We do not yet support a dynamic NGROUPS, but we
may in the future.

MFC after: 2 weeks

In the old-style jail command line, explicitly set parameters from the
security.jail.* sysctls since jail_set(2) doesn't do it implicitly.

Approved by: bz (mentor)

Add support for the arbitrary named jail parameters used by jail_set(2)
and jail_get(2). Jail(8) can now create jails using a "name=value"
format instead of just specifying a limited set of fixed parameters; it
can also modify parameters of existing jails. Jls(8) can display all
parameters of jails, or a specified set of parameters. The available
parameters are gathered from the kernel, and not hard-coded into these
programs.

Small patches on killall(1) and jexec(8) to support jail names with
jail_get(2).

Approved by: bz (mentor)

With the permission of phk@ change the license on remaining jail code
to a 2 clause BSD license.

Approved by: phk
Approved by: bz (mentor)

MFp4:
Bring in updated jail support from bz_jail branch.

This enhances the current jail implementation to permit multiple
addresses per jail. In addtion to IPv4, IPv6 is supported as well.
Due to updated checks it is even possible to have jails without
an IP address at all, which basically gives one a chroot with
restricted process view, no networking,..

SCTP support was updated and supports IPv6 in jails as well.

Cpuset support permits jails to be bound to specific processor
sets after creation.

Jails can have an unrestricted (no duplicate protection, etc.) name
in addition to the hostname. The jail name cannot be changed from
within a jail and is considered to be used for management purposes
or as audit-token in the future.

DDB 'show jails' command was added to aid debugging.

Proper compat support permits 32bit jail binaries to be used on 64bit
systems to manage jails. Also backward compatibility was preserved where
possible: for jail v1 syscalls, as well as with user space management
utilities.

Both jail as well as prison version were updated for the new features.
A gap was intentionally left as the intermediate versions had been
used by various patches floating around the last years.

Bump __FreeBSD_version for the afore mentioned and in kernel changes.

Special thanks to:
- Pawel Jakub Dawidek (pjd) for his multi-IPv4 patches
and Olivier Houchard (cognet) for initial single-IPv6 patches.
- Jeff Roberson (jeff) and Randall Stewart (rrs) for their
help, ideas and review on cpuset and SCTP support.
- Robert Watson (rwatson) for lots and lots of help, discussions,
suggestions and review of most of the patch at various stages.
- John Baldwin (jhb) for his help.
- Simon L. Nielsen (simon) as early adopter testing changes
on cluster machines as well as all the testers and people
who provided feedback the last months on freebsd-jail and
other channels.
- My employer, CK Software GmbH, for the support so I could work on this.

Reviewed by: (see above)
MFC after: 3 months (this is just so that I get the mail)
X-MFC Before: 7.2-RELEASE if possible

correct strtol(3) usage and style(9)

Reviewed by: maxim
MFC after: 2 weeks

o Style(9) the previous commit a bit.

Add the -s option to set jail's securelevel. This is useful for jails run with non-root privileges.

PR: bin/80242
MFC after: 2 weeks

o Do not mangle current session user login name with jail -u|-U.

PR: bin/94730
Submitted by: Frank Behrens
MFC after: 1 month

Add [-J jid_file] option to write out a JidFile, similar to a PidFile,
containing the jailid, path, hostname, ip and the command used to start
the jail.

PR: misc/89883
Submitted by: L. Jason Godsey <lannygodsey -at- yahoo.com>
Reviewed by: phk
MFC after: 1 week

Initialize lcap and pwd to NULL. This allows a WARNS=6 clean build,
hence bump it to 6.

Note that the last commit message was not quite accurate. While the
assumption exists in the code, it's not possible to have an
uninitialized p there because if lflag is set when username is NULL
then execution would be terminated earlier.

The code path in main() dealing with lflag assumes that p was
initialized with NULL, while it is not. So let's initialize
it.

Pass an array of gid_t rather than an array of int to getgroups().

PR: 56646

o Add -l option to jail(8) similar to su(1): before running jail'ed
program under specific user's credentials, clean the environment and
set only a few variables.

PR: bin/70024
Submitted by: demon
MFC after: 1 month

Prepare jail(8) utility for new functionality which will limit
seeing status of mounted file system for jailed processes.
Pass full path of jail's root directory to the kernel. mount(8) utility is
doing the same thing already.

o Implement -U flag: run command as user which exists only in jail.
o getpwnam(3) returns NULL and does not set errno when the user does
not exist. Bail out with "no such user" instead of "Unknown error: 0".

PR: bin/67262
Submitted by: demon (-U flag)
MFC after: 3 weeks

add FBSDID

Force output of jail ID (if necessary) before excuting the command,
otherwise redirection of stdout to a file using block buffering will
not complete in time.

o Add jls(8) for listing active jails.
o Add jexec(8) to execute a command in an existing jail.
o Add -j option for killall(1) to kill all processes in a specified
jail.
o Add -i option to jail(8) to output jail ID of newly created jail.

Free login_cap(3) resources after usage.

Submitted by: demon

o Fix error messages formatting, style.

Prodded by: bde
Reviewed by: bde

o Add -u <username> flag to jail(8): set user context before exec.

PR: bin/44320
Submitted by: Mike Matsnev <mike@po.cs.msu.su>
Reviewed by: -current
MFC after: 6 weeks

Usage style sweep: spell "usage" with a small 'u'.
Also change one case of blatant __progname abuse (several more remain)
This commit does not touch anything in src/{contrib,crypto,gnu}/.

Add missing includes and sort includes.

Include missing header files which define functions for which gcc has
builtints (e.g., exit, strcmp).

Add a version number field to the jail(2) argument so that future changes
can be handled intelligently.

WARNING: you will need to reinstall #includes and recompile jail(8).

$Id$ -> $FreeBSD$

Various cosmetics.

Submitted by: Rudolf Cejka <cejkar@dcse.fee.vutbr.cz>
Reviewed by: phk

Fix various bogons.

Submitted by: Rudolf Cejka <cejkar@dcse.fee.vutbr.cz>
Reviewed by: phk

This Implements the mumbled about "Jail" feature.

This is a seriously beefed up chroot kind of thing. The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.

For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact: "real virtual servers".

Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.

Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.

It generally does what one would expect, but setting up a jail
still takes a little knowledge.

A few notes:

I have no scripts for setting up a jail, don't ask me for them.

The IP number should be an alias on one of the interfaces.

mount a /proc in each jail, it will make ps more useable.

/proc/<pid>/status tells the hostname of the prison for
jailed processes.

Quotas are only sensible if you have a mountpoint per prison.

There are no privisions for stopping resource-hogging.

Some "#ifdef INET" and similar may be missing (send patches!)

If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!

Tools, comments, patches & documentation most welcome.

Have fun...

Sponsored by: http://www.rndassociates.com/
Run for almost a year by: http://www.servetheweb.com/