2003-11-20 02:46:44 +00:00
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.\" Copyright (c) 2000, 2003 Robert N. M. Watson
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2011-06-17 16:21:03 +00:00
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.\" Copyright (c) 2008-2011 James Gritton
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2001-12-14 10:18:15 +00:00
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.\" All rights reserved.
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2000-02-20 02:51:11 +00:00
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.\"
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2001-12-14 10:18:15 +00:00
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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2000-02-20 02:51:11 +00:00
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.\"
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2001-12-14 10:18:15 +00:00
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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2000-02-20 02:51:11 +00:00
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.\"
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2001-12-14 10:18:15 +00:00
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.\" $FreeBSD$
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1999-05-04 18:20:53 +00:00
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.\"
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2010-10-20 20:42:33 +00:00
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.Dd October 20, 2010
|
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/
1999-04-28 11:38:52 +00:00
|
|
|
.Dt JAIL 8
|
2001-07-10 15:12:08 +00:00
|
|
|
.Os
|
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/
1999-04-28 11:38:52 +00:00
|
|
|
.Sh NAME
|
|
|
|
.Nm jail
|
2010-10-20 20:42:33 +00:00
|
|
|
.Nd "manage system jails"
|
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/
1999-04-28 11:38:52 +00:00
|
|
|
.Sh SYNOPSIS
|
2000-11-20 20:10:44 +00:00
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.Nm
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2010-10-20 20:42:33 +00:00
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.Op Fl dhilqv
|
2009-05-27 14:30:26 +00:00
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.Op Fl J Ar jid_file
|
2010-10-20 20:42:33 +00:00
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.Op Fl u Ar username
|
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.Op Fl U Ar username
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.Op Fl cmr
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.Ar param Ns = Ns Ar value ...
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.Op Cm command Ns = Ns Ar command ...
|
2009-05-27 14:30:26 +00:00
|
|
|
.Nm
|
2010-10-20 20:42:33 +00:00
|
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.Op Fl dqv
|
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.Op Fl f Ar conf_file
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|
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|
.Op Fl p Ar limit
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.Op Fl cmr
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.Op Ar jail
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.Nm
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.Op Fl qv
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.Op Fl f Ar conf_file
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.Op Fl rR
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.Op Cm * | Ar jail ...
|
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.Nm
|
|
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.Op Fl dhilqv
|
2005-12-03 17:32:39 +00:00
|
|
|
.Op Fl J Ar jid_file
|
2010-10-20 20:42:33 +00:00
|
|
|
.Op Fl u Ar username
|
|
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|
.Op Fl U Ar username
|
|
|
|
.Op Fl n Ar jailname
|
2006-05-11 13:04:23 +00:00
|
|
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.Op Fl s Ar securelevel
|
2010-10-20 20:42:33 +00:00
|
|
|
.Op Ar path hostname [ Ar ip Ns [ Ns Ar ,... Ns ]] Ar command ...
|
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/
1999-04-28 11:38:52 +00:00
|
|
|
.Sh DESCRIPTION
|
|
|
|
The
|
|
|
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.Nm
|
2010-10-20 20:42:33 +00:00
|
|
|
utility creates new jails, or modifies or removes existing jails.
|
|
|
|
A jail is specified via parameters on the command line, or in the
|
|
|
|
.Xr jail.conf 5
|
|
|
|
file.
|
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/
1999-04-28 11:38:52 +00:00
|
|
|
.Pp
|
2010-10-20 20:42:33 +00:00
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At least one of the options
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.Fl c ,
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.Fl m
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or
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.Fl r
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must be specified.
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These options are used alone or in combination describe the operation to
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perform:
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.Bl -tag -width indent
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.It Fl c
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Create a new jail.
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The jail
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.Va jid
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and
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.Va name
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parameters (if specified) on the command line,
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or any jails
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must not refer to an existing jail.
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.It Fl m
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Modify an existing jail.
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One of the
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.Va jid
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or
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.Va name
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parameters must exist and refer to an existing jail.
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Some parameters may not be changed on a running jail.
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.It Fl r
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Remove the
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.Ar jail
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specified by jid or name.
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All jailed processes are killed, and all children of this jail are also
|
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removed.
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.It Fl rc
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Restart an existing jail.
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The jail is first removed and then re-created, as if
|
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.Dq Nm Fl c
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and
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.Dq Nm Fl r
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were run in succession.
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.It Fl cm
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Create a jail if it does not exist, or modify the jail if it does exist.
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.It Fl mr
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Modify an existing jail.
|
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The jail may be restarted if necessary to modify parameters than could
|
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|
not otherwise be changed.
|
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.It Fl cmr
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Create a jail if it doesn't exist, or modify (and possibly restart) the
|
|
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jail if it does exist.
|
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.El
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.Pp
|
|
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|
Other available options are:
|
2009-05-27 14:30:26 +00:00
|
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.Bl -tag -width indent
|
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.It Fl d
|
2010-10-20 20:42:33 +00:00
|
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|
Allow making changes to a dying jail, equivalent to the
|
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.Va allow.dying
|
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|
parameter.
|
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.It Fl f Ar conf_file
|
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Use configuration file
|
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.Ar conf_file
|
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|
instead of the default
|
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|
.Pa /etc/jail.conf .
|
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
2008-11-29 14:32:14 +00:00
|
|
|
.It Fl h
|
2009-05-27 14:30:26 +00:00
|
|
|
Resolve the
|
|
|
|
.Va host.hostname
|
|
|
|
parameter (or
|
|
|
|
.Va hostname )
|
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
2008-11-29 14:32:14 +00:00
|
|
|
and add all IP addresses returned by the resolver
|
2010-10-20 20:42:33 +00:00
|
|
|
to the list of addresses for this prison.
|
|
|
|
This is equivalent to the
|
|
|
|
.Va ip_hostname
|
2009-05-27 14:30:26 +00:00
|
|
|
parameter.
|
2010-10-20 20:42:33 +00:00
|
|
|
.It Fl i
|
|
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|
Output (only) the jail identifier of the newly created jail(s).
|
|
|
|
This implies the
|
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.Fl q
|
|
|
|
option.
|
2005-12-03 17:32:39 +00:00
|
|
|
.It Fl J Ar jid_file
|
2006-09-29 17:57:04 +00:00
|
|
|
Write a
|
|
|
|
.Ar jid_file
|
2010-10-20 20:42:33 +00:00
|
|
|
file, containing parameters used to start the jail.
|
2004-08-15 08:21:50 +00:00
|
|
|
.It Fl l
|
2010-10-20 20:42:33 +00:00
|
|
|
Run commands in a clean environment.
|
|
|
|
This is deprecated and is equivalent to the exec.clean parameter.
|
|
|
|
.It Fl n Ar jailname
|
|
|
|
Set the jail's name.
|
|
|
|
This is deprecated and is equivalent to the
|
|
|
|
.Va name
|
|
|
|
parameter.
|
|
|
|
.It Fl p Ar limit
|
|
|
|
Limit the number of commands from
|
|
|
|
.Va exec.*
|
|
|
|
that can run simultaneously.
|
|
|
|
.It Fl q
|
|
|
|
Suppress the message printed whenever a jail is created, modified or removed.
|
|
|
|
Only error messages will be printed.
|
|
|
|
.It Fl R
|
|
|
|
A variation of the
|
|
|
|
.Fl r
|
|
|
|
option that removes an existing jail without using the configuration file.
|
|
|
|
No removal-related parameters for this jail will be used - the jail will
|
|
|
|
simply be removed.
|
2006-05-11 13:04:23 +00:00
|
|
|
.It Fl s Ar securelevel
|
2009-05-27 14:30:26 +00:00
|
|
|
Set the
|
2006-09-29 17:57:04 +00:00
|
|
|
.Va kern.securelevel
|
2009-05-27 14:30:26 +00:00
|
|
|
MIB entry to the specified value inside the newly created jail.
|
2010-10-20 20:42:33 +00:00
|
|
|
This is deprecated and is equivalent to the
|
2009-05-27 14:30:26 +00:00
|
|
|
.Va securelevel
|
|
|
|
parameter.
|
2003-03-27 12:16:58 +00:00
|
|
|
.It Fl u Ar username
|
2010-10-20 20:42:33 +00:00
|
|
|
The user name from host environment as whom jailed commands should run.
|
|
|
|
This is deprecated and is equivalent to the
|
|
|
|
.Va exec.jail_user
|
2009-05-27 14:30:26 +00:00
|
|
|
and
|
2010-10-20 20:42:33 +00:00
|
|
|
.Va exec.system_jail_user
|
|
|
|
parameters.
|
|
|
|
.It Fl U Ar username
|
|
|
|
The user name from jailed environment as whom jailed commands should run.
|
|
|
|
This is deprecated and is equivalent to the
|
|
|
|
.Va exec.jail_user
|
|
|
|
parameter.
|
|
|
|
.It Fl v
|
|
|
|
Print a message on every operation, such as running commands and
|
|
|
|
mounting filesystems.
|
2009-05-27 14:30:26 +00:00
|
|
|
.El
|
|
|
|
.Pp
|
2010-10-20 20:42:33 +00:00
|
|
|
If no arguments are given after the options, the operation (except
|
|
|
|
remove) will be performed on all jails specified in the
|
|
|
|
.Xr jail.conf 5
|
|
|
|
file.
|
|
|
|
A single argument of a jail name will operate only on the specified jail.
|
|
|
|
The
|
2009-05-27 14:30:26 +00:00
|
|
|
.Fl r
|
2010-10-20 20:42:33 +00:00
|
|
|
and
|
|
|
|
.Fl R
|
|
|
|
options can also remove running jails that aren't in the
|
|
|
|
.Xr jail.conf 5
|
|
|
|
file, specified by name or jid.
|
|
|
|
.P
|
|
|
|
An argument of
|
|
|
|
.Dq *
|
2012-01-31 19:45:32 +00:00
|
|
|
is a wildcard that will operate on all jails, regardless of whether
|
|
|
|
they appear in
|
|
|
|
.Xr jail.conf 5 ;
|
|
|
|
this is the surest way for
|
2010-10-20 20:42:33 +00:00
|
|
|
.Fl r
|
|
|
|
to remove all jails.
|
|
|
|
If hierarchical jails exist, a partial-matching wildcard definition may
|
|
|
|
be specified.
|
|
|
|
For example, an argument of
|
|
|
|
.Dq foo.*
|
|
|
|
would apply to jails with names like
|
|
|
|
.Dq foo.bar
|
|
|
|
and
|
|
|
|
.Dq foo.bar.baz .
|
2009-05-27 14:30:26 +00:00
|
|
|
.Pp
|
2010-10-20 20:42:33 +00:00
|
|
|
A jail may be specified with parameters directly on the command line.
|
|
|
|
In this case, the
|
|
|
|
.Xr jail.conf 5
|
|
|
|
file will not be used.
|
|
|
|
For backward compatibility, the command line may also have four fixed
|
|
|
|
parameters, without names:
|
2009-05-27 14:30:26 +00:00
|
|
|
.Ar path ,
|
|
|
|
.Ar hostname ,
|
|
|
|
.Ar ip ,
|
|
|
|
and
|
|
|
|
.Ar command .
|
2010-10-20 20:42:33 +00:00
|
|
|
This mode will always create a new jail, and the
|
2009-05-27 14:30:26 +00:00
|
|
|
.Fl c
|
|
|
|
and
|
2009-05-29 21:17:22 +00:00
|
|
|
.Fl m
|
2009-05-27 14:30:26 +00:00
|
|
|
options don't apply (and must not exist).
|
2010-10-20 20:42:33 +00:00
|
|
|
.Ss Jail Parameters
|
|
|
|
Parameters in the
|
|
|
|
.Xr jail.conf 5
|
|
|
|
file, or on the command line, are generally in
|
|
|
|
.Dq name=value
|
|
|
|
form.
|
|
|
|
Some parameters are boolean, and do not have a value but are set by the
|
|
|
|
name alone with or without a
|
|
|
|
.Dq no
|
|
|
|
prefix, e.g.
|
|
|
|
.Va persist
|
|
|
|
or
|
|
|
|
.Va nopersist .
|
|
|
|
They can also be given the values
|
|
|
|
.Dq true
|
|
|
|
and
|
|
|
|
.Dq false .
|
|
|
|
Other partameters may have more than one value, specified as a
|
|
|
|
comma-separated list or with
|
|
|
|
.Dq +=
|
|
|
|
in the configuration file (see
|
|
|
|
.Xr jail.conf 5
|
|
|
|
for details).
|
2009-05-27 14:30:26 +00:00
|
|
|
.Pp
|
2010-10-20 20:42:33 +00:00
|
|
|
The
|
|
|
|
.Nm
|
|
|
|
utility recognizes two classes of parameters. There are the true jail
|
|
|
|
parameters that are passed to the kernel when the jail is created,
|
|
|
|
can be seen with
|
|
|
|
.Xr jls 8 ,
|
|
|
|
and can (usually) be changed with
|
|
|
|
.Dq Nm Fl m.
|
|
|
|
Then there are pseudo-parameters that are only used by
|
|
|
|
.Nm
|
|
|
|
itself.
|
|
|
|
.Pp
|
|
|
|
Jails have a set a core parameters, and kernel modules can add their own
|
|
|
|
jail parameters.
|
2009-05-27 14:30:26 +00:00
|
|
|
The current set of available parameters can be retrieved via
|
|
|
|
.Dq Nm sysctl Fl d Va security.jail.param .
|
2010-10-20 20:42:33 +00:00
|
|
|
Any parameters not set will be given default values, often based on the
|
|
|
|
current environment.
|
2009-05-27 14:30:26 +00:00
|
|
|
The core parameters are:
|
|
|
|
.Bl -tag -width indent
|
|
|
|
.It Va jid
|
|
|
|
The jail identifier.
|
|
|
|
This will be assigned automatically to a new jail (or can be explicitly
|
|
|
|
set), and can be used to identify the jail for later modification, or
|
|
|
|
for such commands as
|
|
|
|
.Xr jls 8
|
|
|
|
or
|
|
|
|
.Xr jexec 8 .
|
|
|
|
.It Va name
|
|
|
|
The jail name.
|
|
|
|
This is an arbitrary string that identifies a jail (except it may not
|
|
|
|
contain a
|
|
|
|
.Sq \&. ) .
|
|
|
|
Like the
|
|
|
|
.Va jid ,
|
|
|
|
it can be passed to later
|
|
|
|
.Nm
|
|
|
|
commands, or to
|
|
|
|
.Xr jls 8
|
|
|
|
or
|
|
|
|
.Xr jexec 8 .
|
|
|
|
If no
|
|
|
|
.Va name
|
|
|
|
is supplied, a default is assumed that is the same as the
|
|
|
|
.Va jid .
|
|
|
|
The
|
2010-10-20 20:42:33 +00:00
|
|
|
.Va name
|
|
|
|
parameter is implied by the
|
|
|
|
.Xr jail.conf 5
|
|
|
|
file format, and need not be explicitly set when using the configuration
|
|
|
|
file.
|
|
|
|
.It Va path
|
|
|
|
The directory which is to be the root of the prison.
|
|
|
|
Any commands run inside the prison, either by
|
|
|
|
.Nm
|
|
|
|
or from
|
|
|
|
.Xr jexec 8 ,
|
|
|
|
are run from this directory.
|
2009-05-27 14:30:26 +00:00
|
|
|
.It Va ip4.addr
|
2010-10-20 20:42:33 +00:00
|
|
|
A list of IPv4 addresses assigned to the prison.
|
2010-05-05 08:43:47 +00:00
|
|
|
If this is set, the jail is restricted to using only these addresses.
|
2009-05-27 14:30:26 +00:00
|
|
|
Any attempts to use other addresses fail, and attempts to use wildcard
|
|
|
|
addresses silently use the jailed address instead.
|
|
|
|
For IPv4 the first address given will be kept used as the source address
|
|
|
|
in case source address selection on unbound sockets cannot find a better
|
|
|
|
match.
|
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
2008-11-29 14:32:14 +00:00
|
|
|
It is only possible to start multiple jails with the same IP address,
|
|
|
|
if none of the jails has more than this single overlapping IP address
|
2009-05-27 14:30:26 +00:00
|
|
|
assigned to itself.
|
2010-01-17 12:57:11 +00:00
|
|
|
.It Va ip4.saddrsel
|
|
|
|
A boolean option to change the formerly mentioned behaviour and disable
|
|
|
|
IPv4 source address selection for the prison in favour of the primary
|
|
|
|
IPv4 address of the jail.
|
2010-10-20 20:42:33 +00:00
|
|
|
Source address selection is enabled by default for all jails and the
|
2010-01-17 12:57:11 +00:00
|
|
|
.Va ip4.nosaddrsel
|
|
|
|
setting of a parent jail is not inherited for any child jails.
|
2009-07-25 14:48:57 +00:00
|
|
|
.It Va ip4
|
2010-08-01 09:37:36 +00:00
|
|
|
Control the availability of IPv4 addresses.
|
2009-07-25 14:48:57 +00:00
|
|
|
Possible values are
|
|
|
|
.Dq inherit
|
|
|
|
to allow unrestricted access to all system addresses,
|
|
|
|
.Dq new
|
|
|
|
to restrict addresses via
|
|
|
|
.Va ip4.addr
|
|
|
|
above, and
|
|
|
|
.Dq disable
|
|
|
|
to stop the jail from using IPv4 entirely.
|
|
|
|
Setting the
|
|
|
|
.Va ip4.addr
|
|
|
|
parameter implies a value of
|
|
|
|
.Dq new .
|
2010-01-17 12:57:11 +00:00
|
|
|
.It Va ip6.addr , Va ip6.saddrsel , Va ip6
|
|
|
|
A set of IPv6 options for the prison, the counterparts to
|
|
|
|
.Va ip4.addr ,
|
|
|
|
.Va ip4.saddrsel
|
2009-07-25 14:48:57 +00:00
|
|
|
and
|
|
|
|
.Va ip4
|
2009-05-27 14:30:26 +00:00
|
|
|
above.
|
2010-10-20 20:42:33 +00:00
|
|
|
.It vnet
|
|
|
|
Create the prison with its own virtual network stack,
|
|
|
|
with its own network interfaces, addresses, routing table, etc.
|
|
|
|
The kernel must have been compiled with the
|
|
|
|
.Sy VIMAGE option
|
|
|
|
for this to be available.
|
|
|
|
Possible values are
|
|
|
|
.Dq inherit
|
|
|
|
to use the system network stack, possibly with restricted IP addresses,
|
|
|
|
and
|
|
|
|
.Dq new
|
|
|
|
to create a new network stack.
|
2009-05-27 14:30:26 +00:00
|
|
|
.It Va host.hostname
|
2010-10-20 20:42:33 +00:00
|
|
|
The hostname of the prison.
|
2009-05-29 21:27:12 +00:00
|
|
|
Other similar parameters are
|
|
|
|
.Va host.domainname ,
|
|
|
|
.Va host.hostuuid
|
|
|
|
and
|
|
|
|
.Va host.hostid .
|
2009-07-25 14:48:57 +00:00
|
|
|
.It Va host
|
|
|
|
Set the origin of hostname and related information.
|
|
|
|
Possible values are
|
|
|
|
.Dq inherit
|
|
|
|
to use the system information and
|
|
|
|
.Dq new
|
|
|
|
for the jail to use the information from the above fields.
|
|
|
|
Setting any of the above fields implies a value of
|
|
|
|
.Dq new .
|
2009-05-27 14:30:26 +00:00
|
|
|
.It Va securelevel
|
|
|
|
The value of the jail's
|
|
|
|
.Va kern.securelevel
|
|
|
|
sysctl.
|
|
|
|
A jail never has a lower securelevel than the default system, but by
|
|
|
|
setting this parameter it may have a higher one.
|
|
|
|
If the system securelevel is changed, any jail securelevels will be at
|
|
|
|
least as secure.
|
2009-06-23 20:35:51 +00:00
|
|
|
.It Va children.max
|
|
|
|
The number of child jails allowed to be created by this jail (or by
|
|
|
|
other jails under this jail).
|
|
|
|
This limit is zero by default, indicating the jail is not allowed to
|
|
|
|
create child jails.
|
|
|
|
See the
|
2010-10-20 20:42:33 +00:00
|
|
|
.Sx "Hierarchical Jails"
|
2009-06-23 20:35:51 +00:00
|
|
|
section for more information.
|
|
|
|
.It Va children.cur
|
|
|
|
The number of descendents of this jail, including its own child jails
|
|
|
|
and any jails created under them.
|
2009-05-27 14:30:26 +00:00
|
|
|
.It Va enforce_statfs
|
|
|
|
This determines which information processes in a jail are able to get
|
|
|
|
about mount points.
|
|
|
|
It affects the behaviour of the following syscalls:
|
|
|
|
.Xr statfs 2 ,
|
|
|
|
.Xr fstatfs 2 ,
|
|
|
|
.Xr getfsstat 2
|
|
|
|
and
|
|
|
|
.Xr fhstatfs 2
|
|
|
|
(as well as similar compatibility syscalls).
|
|
|
|
When set to 0, all mount points are available without any restrictions.
|
|
|
|
When set to 1, only mount points below the jail's chroot directory are
|
|
|
|
visible.
|
|
|
|
In addition to that, the path to the jail's chroot directory is removed
|
|
|
|
from the front of their pathnames.
|
|
|
|
When set to 2 (default), above syscalls can operate only on a mount-point
|
|
|
|
where the jail's chroot directory is located.
|
|
|
|
.It Va persist
|
|
|
|
Setting this boolean parameter allows a jail to exist without any
|
|
|
|
processes.
|
2010-10-20 20:42:33 +00:00
|
|
|
Normally, a command is run as part of jail creation, and then the jail
|
|
|
|
is destroyed as its last process exits.
|
2010-08-08 23:24:23 +00:00
|
|
|
A new jail must have either the
|
2010-08-06 22:06:12 +00:00
|
|
|
.Va persist
|
2010-08-08 23:24:23 +00:00
|
|
|
parameter or
|
2010-10-20 20:42:33 +00:00
|
|
|
.Va exec.start
|
|
|
|
or
|
2010-08-08 23:24:23 +00:00
|
|
|
.Va command
|
|
|
|
pseudo-parameter set.
|
2009-05-29 21:17:22 +00:00
|
|
|
.It Va cpuset.id
|
2009-05-27 14:30:26 +00:00
|
|
|
The ID of the cpuset associated with this jail (read-only).
|
|
|
|
.It Va dying
|
|
|
|
This is true if the jail is in the process of shutting down (read-only).
|
|
|
|
.It Va parent
|
|
|
|
The
|
|
|
|
.Va jid
|
|
|
|
of the parent of this jail, or zero if this is a top-level jail
|
|
|
|
(read-only).
|
|
|
|
.It Va allow.*
|
|
|
|
Some restrictions of the jail environment may be set on a per-jail
|
|
|
|
basis.
|
|
|
|
With the exception of
|
|
|
|
.Va allow.set_hostname ,
|
|
|
|
these boolean parameters are off by default.
|
|
|
|
.Bl -tag -width indent
|
|
|
|
.It Va allow.set_hostname
|
|
|
|
The jail's hostname may be changed via
|
|
|
|
.Xr hostname 1
|
|
|
|
or
|
|
|
|
.Xr sethostname 3 .
|
|
|
|
.It Va allow.sysvipc
|
|
|
|
A process within the jail has access to System V IPC primitives.
|
|
|
|
In the current jail implementation, System V primitives share a single
|
|
|
|
namespace across the host and jail environments, meaning that processes
|
|
|
|
within a jail would be able to communicate with (and potentially interfere
|
|
|
|
with) processes outside of the jail, and in other jails.
|
|
|
|
.It Va allow.raw_sockets
|
|
|
|
The prison root is allowed to create raw sockets.
|
|
|
|
Setting this parameter allows utilities like
|
|
|
|
.Xr ping 8
|
|
|
|
and
|
|
|
|
.Xr traceroute 8
|
|
|
|
to operate inside the prison.
|
|
|
|
If this is set, the source IP addresses are enforced to comply
|
|
|
|
with the IP address bound to the jail, regardless of whether or not
|
|
|
|
the
|
|
|
|
.Dv IP_HDRINCL
|
|
|
|
flag has been set on the socket.
|
|
|
|
Since raw sockets can be used to configure and interact with various
|
|
|
|
network subsystems, extra caution should be used where privileged access
|
|
|
|
to jails is given out to untrusted parties.
|
|
|
|
.It Va allow.chflags
|
2009-10-18 19:50:15 +00:00
|
|
|
Normally, privileged users inside a jail are treated as unprivileged by
|
2009-05-27 14:30:26 +00:00
|
|
|
.Xr chflags 2 .
|
|
|
|
When this parameter is set, such users are treated as privileged, and
|
|
|
|
may manipulate system file flags subject to the usual constraints on
|
|
|
|
.Va kern.securelevel .
|
|
|
|
.It Va allow.mount
|
|
|
|
privileged users inside the jail will be able to mount and unmount file
|
|
|
|
system types marked as jail-friendly.
|
|
|
|
The
|
|
|
|
.Xr lsvfs 1
|
|
|
|
command can be used to find file system types available for mount from
|
|
|
|
within a jail.
|
|
|
|
.It Va allow.quotas
|
|
|
|
The prison root may administer quotas on the jail's filesystem(s).
|
|
|
|
This includes filesystems that the jail may share with other jails or
|
|
|
|
with non-jailed parts of the system.
|
|
|
|
.It Va allow.socket_af
|
|
|
|
Sockets within a jail are normally restricted to IPv4, IPv6, local
|
|
|
|
(UNIX), and route. This allows access to other protocol stacks that
|
|
|
|
have not had jail functionality added to them.
|
|
|
|
.El
|
2003-03-27 12:16:58 +00:00
|
|
|
.El
|
|
|
|
.Pp
|
2010-10-20 20:42:33 +00:00
|
|
|
There are pseudo-parameters that aren't passed to the kernel, but are
|
|
|
|
used by
|
|
|
|
.Nm
|
|
|
|
to set up the prison environment, often by running specified commands
|
|
|
|
when jails are created or removed.
|
|
|
|
The
|
|
|
|
.Va exec.*
|
|
|
|
command parameters are
|
|
|
|
.Xr sh 1
|
|
|
|
command lines that are run in either the system or prison environment.
|
|
|
|
They may be given multiple values, which run would the specified
|
|
|
|
commands in sequence.
|
|
|
|
All commands must succed (return a zero exit status), or the jail will
|
|
|
|
not be created or removed.
|
|
|
|
.Pp
|
|
|
|
The pseudo-parameters are:
|
|
|
|
.Bl -tag -width indent
|
|
|
|
.It Va exec.prestart
|
|
|
|
Command(s) to run in the system environment before a prison is created.
|
|
|
|
.It Va exec.start
|
|
|
|
Command(s) to run in the prison environment when a jail is created.
|
|
|
|
A typical command to run is
|
|
|
|
.Dq sh /etc/rc .
|
|
|
|
.It Va command
|
|
|
|
A synonym for
|
|
|
|
.Va exec.start
|
|
|
|
for use when specifying a prison directly on the command line.
|
|
|
|
Unlike other parameters whose value is a single string,
|
|
|
|
.Va command
|
|
|
|
uses the remainder of the
|
|
|
|
.Nm
|
|
|
|
command line as its own arguments.
|
|
|
|
.It Va exec.poststart
|
|
|
|
Command(s) to run in the system environment after a jail is created,
|
|
|
|
and after any
|
|
|
|
.Va exec.start
|
|
|
|
commands have completed.
|
|
|
|
.It Va exec.prestop
|
|
|
|
Command(s) to run in the system environment before a jail is removed.
|
|
|
|
.It Va exec.stop
|
|
|
|
Command(s) to run in the prison environment before a jail is removed,
|
|
|
|
and after any
|
|
|
|
.Va exec.prestop
|
|
|
|
commands have completed.
|
|
|
|
A typical command to run is
|
|
|
|
.Dq sh /etc/rc.shutdown .
|
|
|
|
.It Va exec.poststop
|
|
|
|
Command(s) to run in the system environment after a jail is removed.
|
|
|
|
.It Va exec.clean
|
|
|
|
Run commands in a clean environment.
|
|
|
|
The environment is discarded except for
|
|
|
|
.Ev HOME , SHELL , TERM
|
|
|
|
and
|
|
|
|
.Ev USER .
|
|
|
|
.Ev HOME
|
|
|
|
and
|
|
|
|
.Ev SHELL
|
|
|
|
are set to the target login's default values.
|
|
|
|
.Ev USER
|
|
|
|
is set to the target login.
|
|
|
|
.Ev TERM
|
|
|
|
is imported from the current environment.
|
|
|
|
The environment variables from the login class capability database for the
|
|
|
|
target login are also set.
|
|
|
|
.It Va exec.jail_user
|
|
|
|
The user to run commands as, when running in the prison environment.
|
|
|
|
The default is to run the commands as the current user.
|
|
|
|
.It Va exec.system_jail_user
|
|
|
|
This boolean option looks for the
|
|
|
|
.Va exec.jail_user
|
|
|
|
in the system
|
|
|
|
.Xr passwd 5
|
|
|
|
file, instead of in the prison's file.
|
|
|
|
.It Va exec.system_user
|
|
|
|
The user to run commands as, when running in the system environment.
|
|
|
|
The default is to run the commands as the current user.
|
|
|
|
.It Va exec.timeout
|
|
|
|
The maximum amount of time to wait for a command to complete.
|
|
|
|
If a command is still running after this many seconds have passed,
|
|
|
|
the jail not be created or removed.
|
|
|
|
.It Va exec.consolelog
|
|
|
|
A file to direct command output (stdout and stderr) to.
|
|
|
|
.It Va exec.fib
|
|
|
|
The FIB (routing table) to set when running commands inside the prison.
|
|
|
|
.It Va stop.timeout
|
|
|
|
The maximum amount of time to wait for a prison's processes to exit
|
|
|
|
after sending them a
|
|
|
|
.Dv SIGTERM
|
|
|
|
signal (which happens after the
|
|
|
|
.Va exec.stop commands have completed).
|
|
|
|
After this many seconds have passed, the prison will be removed, which
|
|
|
|
will kill any remaining processes.
|
|
|
|
If this is set to zero, no
|
|
|
|
.Dv SIGTERM
|
|
|
|
is sent and the prison is immediately removed.
|
|
|
|
The default is 10 seconds.
|
|
|
|
.It Va interface
|
|
|
|
A network interface to add the prison's IP addresses
|
|
|
|
.Va ( ip4.addr
|
|
|
|
and
|
|
|
|
.Va ip6.addr )
|
|
|
|
to.
|
|
|
|
An alias for each address will be added to the interface before the
|
|
|
|
prison is created, and will be removed from the interface after the
|
|
|
|
prison is removed.
|
|
|
|
.It Op Va ip4.addr
|
|
|
|
In addition to the IP addresses that are passed to the kernel, and
|
|
|
|
interface and/or a netmask may also be specified, in the form
|
|
|
|
.Dq Ar interface Ns | Ns Ar ip-address Ns / Ns Ar netmask .
|
|
|
|
If an interface is given before the IP address, an alias for the address
|
|
|
|
will be added to that interface, as it is with the
|
|
|
|
.Va interface
|
|
|
|
parameter. If a netmask in either dotted-quad or CIDR form is given
|
|
|
|
after IP address, it will be used when adding the IP alias.
|
|
|
|
.It Op Va ip6.addr
|
|
|
|
In addition to the IP addresses that are passed to the kernel,
|
|
|
|
and interface and/or a prefix may also be specified, in the form
|
|
|
|
.Dq Ar interface Ns | Ns Ar ip-address Ns / Ns Ar prefix .
|
|
|
|
.It Va vnet.interface
|
|
|
|
A network interface to give to a vnet-enabled jail after is it created.
|
|
|
|
The interface will automatically be returned when the jail is removed.
|
|
|
|
.It Va ip_hostname
|
|
|
|
Resolve the
|
|
|
|
.Va host.hostname
|
|
|
|
parameter and add all IP addresses returned by the resolver
|
|
|
|
to the list of addresses
|
|
|
|
.Va ( ip4.addr
|
|
|
|
or
|
|
|
|
.Va ip6.addr )
|
|
|
|
for this prison.
|
|
|
|
This may affect default address selection for outgoing IPv4 connections
|
|
|
|
of prisons.
|
|
|
|
The address first returned by the resolver for each address family
|
|
|
|
will be used as primary address.
|
|
|
|
.It Va mount
|
|
|
|
A filesystem to mount before creating the jail (and to unmount after
|
|
|
|
removing it), given as a single
|
|
|
|
.Xr fstab 5
|
|
|
|
line.
|
|
|
|
.It Va mount.fstab
|
|
|
|
An
|
|
|
|
.Xr fstab 5
|
|
|
|
format file containing filesystems to mount before creating a jail.
|
|
|
|
.It Va mount.devfs
|
|
|
|
Mount a
|
|
|
|
.Xr devfs
|
|
|
|
filesystem on the chrooted /dev directory, and run
|
|
|
|
.Xr devfs 8
|
|
|
|
to restrict the devices visible inside the prison.
|
|
|
|
.It Va mount.devfs.ruleset
|
|
|
|
The ruleset from
|
|
|
|
.Xr devfs.rules 5
|
|
|
|
to use when mounting a devfs filesystem.
|
|
|
|
The default ruleset is
|
|
|
|
.Dq devfsrules_jail .
|
|
|
|
.It Va allow.dying
|
|
|
|
Allow making changes to a
|
|
|
|
.Va dying
|
|
|
|
jail.
|
|
|
|
.It Va depend
|
|
|
|
Specify a jail (or jails) that this jail depends on.
|
|
|
|
Any such jails must be fully created, up to the last
|
|
|
|
.Va exec.poststart
|
|
|
|
command, before any action will taken to create this jail.
|
|
|
|
When jails are removed the opposite is true:
|
|
|
|
this jail must be fully removed, up to the last
|
|
|
|
.Va exec.poststop
|
|
|
|
command, before the jail(s) it depends on are stopped.
|
|
|
|
.El
|
|
|
|
.Sh EXAMPLES
|
2003-11-20 03:47:50 +00:00
|
|
|
Jails are typically set up using one of two philosophies: either to
|
|
|
|
constrain a specific application (possibly running with privilege), or
|
2004-06-05 20:27:10 +00:00
|
|
|
to create a
|
|
|
|
.Dq "virtual system image"
|
|
|
|
running a variety of daemons and services.
|
|
|
|
In both cases, a fairly complete file system install of
|
|
|
|
.Fx
|
|
|
|
is
|
2003-11-20 03:47:50 +00:00
|
|
|
required, so as to provide the necessary command line tools, daemons,
|
2004-05-20 06:37:44 +00:00
|
|
|
libraries, application configuration files, etc.
|
2003-11-20 03:47:50 +00:00
|
|
|
However, for a virtual server configuration, a fair amount of
|
2004-06-05 20:27:10 +00:00
|
|
|
additional work is required so as to configure the
|
|
|
|
.Dq boot
|
|
|
|
process.
|
2004-05-20 06:37:44 +00:00
|
|
|
This manual page documents the configuration steps necessary to support
|
2004-02-06 21:05:42 +00:00
|
|
|
either of these steps, although the configuration steps may be
|
2003-11-20 03:47:50 +00:00
|
|
|
refined based on local requirements.
|
2001-12-14 10:18:15 +00:00
|
|
|
.Ss "Setting up a Jail Directory Tree"
|
2005-10-26 20:19:39 +00:00
|
|
|
To set up a jail directory tree containing an entire
|
2002-01-10 15:14:22 +00:00
|
|
|
.Fx
|
2005-10-26 20:19:39 +00:00
|
|
|
distribution, the following
|
|
|
|
.Xr sh 1
|
|
|
|
command script can be used:
|
2001-07-15 08:06:20 +00:00
|
|
|
.Bd -literal
|
1999-07-09 21:35:50 +00:00
|
|
|
D=/here/is/the/jail
|
|
|
|
cd /usr/src
|
2001-12-14 20:20:50 +00:00
|
|
|
mkdir -p $D
|
2001-03-11 20:37:11 +00:00
|
|
|
make world DESTDIR=$D
|
2002-10-22 15:03:51 +00:00
|
|
|
make distribution DESTDIR=$D
|
1999-07-09 21:35:50 +00:00
|
|
|
.Ed
|
2001-12-14 20:20:50 +00:00
|
|
|
.Pp
|
2004-05-20 06:37:44 +00:00
|
|
|
In many cases this example would put far more in the jail than needed.
|
|
|
|
In the other extreme case a jail might contain only one file:
|
2001-12-14 20:20:50 +00:00
|
|
|
the executable to be run in the jail.
|
|
|
|
.Pp
|
|
|
|
We recommend experimentation and caution that it is a lot easier to
|
2002-01-10 15:14:22 +00:00
|
|
|
start with a
|
|
|
|
.Dq fat
|
|
|
|
jail and remove things until it stops working,
|
|
|
|
than it is to start with a
|
|
|
|
.Dq thin
|
|
|
|
jail and add things until it works.
|
2001-12-14 10:18:15 +00:00
|
|
|
.Ss "Setting Up a Jail"
|
2000-02-13 05:15:29 +00:00
|
|
|
Do what was described in
|
2001-12-14 10:18:15 +00:00
|
|
|
.Sx "Setting Up a Jail Directory Tree"
|
|
|
|
to build the jail directory tree.
|
|
|
|
For the sake of this example, we will
|
2000-02-13 05:15:29 +00:00
|
|
|
assume you built it in
|
2010-10-20 20:42:33 +00:00
|
|
|
.Pa /data/jail/testjail ,
|
|
|
|
for a jail named
|
|
|
|
.Dq testjail .
|
2001-12-14 10:18:15 +00:00
|
|
|
Substitute below as needed with your
|
2000-02-13 05:15:29 +00:00
|
|
|
own directory, IP address, and hostname.
|
2003-11-20 03:47:50 +00:00
|
|
|
.Ss "Setting up the Host Environment"
|
2000-02-13 05:15:29 +00:00
|
|
|
First, you will want to set up your real system's environment to be
|
2001-02-01 16:44:04 +00:00
|
|
|
.Dq jail-friendly .
|
2000-02-13 05:15:29 +00:00
|
|
|
For consistency, we will refer to the parent box as the
|
2001-12-14 10:18:15 +00:00
|
|
|
.Dq "host environment" ,
|
2000-02-13 05:15:29 +00:00
|
|
|
and to the jailed virtual machine as the
|
2001-12-14 10:18:15 +00:00
|
|
|
.Dq "jail environment" .
|
2004-06-01 20:32:44 +00:00
|
|
|
Since jail is implemented using IP aliases, one of the first things to do
|
2000-02-13 05:15:29 +00:00
|
|
|
is to disable IP services on the host system that listen on all local
|
2001-12-14 10:18:15 +00:00
|
|
|
IP addresses for a service.
|
2003-11-20 03:47:50 +00:00
|
|
|
If a network service is present in the host environment that binds all
|
|
|
|
available IP addresses rather than specific IP addresses, it may service
|
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
2008-11-29 14:32:14 +00:00
|
|
|
requests sent to jail IP addresses if the jail did not bind the port.
|
2001-12-14 10:18:15 +00:00
|
|
|
This means changing
|
2000-03-24 02:05:54 +00:00
|
|
|
.Xr inetd 8
|
|
|
|
to only listen on the
|
2001-12-14 10:18:15 +00:00
|
|
|
appropriate IP address, and so forth.
|
|
|
|
Add the following to
|
2000-02-13 05:15:29 +00:00
|
|
|
.Pa /etc/rc.conf
|
|
|
|
in the host environment:
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
sendmail_enable="NO"
|
2006-06-11 12:57:41 +00:00
|
|
|
inetd_flags="-wW -a 192.0.2.23"
|
2003-03-18 14:01:02 +00:00
|
|
|
rpcbind_enable="NO"
|
2000-02-13 05:15:29 +00:00
|
|
|
.Ed
|
|
|
|
.Pp
|
2006-06-11 12:57:41 +00:00
|
|
|
.Li 192.0.2.23
|
2001-12-14 10:18:15 +00:00
|
|
|
is the native IP address for the host system, in this example.
|
|
|
|
Daemons that run out of
|
2000-02-18 19:02:22 +00:00
|
|
|
.Xr inetd 8
|
2001-12-14 10:18:15 +00:00
|
|
|
can be easily set to use only the specified host IP address.
|
|
|
|
Other daemons
|
|
|
|
will need to be manually configured\(emfor some this is possible through
|
2000-02-18 19:02:22 +00:00
|
|
|
the
|
|
|
|
.Xr rc.conf 5
|
2004-05-20 06:37:44 +00:00
|
|
|
flags entries; for others it is necessary to modify per-application
|
|
|
|
configuration files, or to recompile the applications.
|
2003-11-20 03:47:50 +00:00
|
|
|
The following frequently deployed services must have their individual
|
|
|
|
configuration files modified to limit the application to listening
|
|
|
|
to a specific IP address:
|
|
|
|
.Pp
|
|
|
|
To configure
|
|
|
|
.Xr sshd 8 ,
|
|
|
|
it is necessary to modify
|
|
|
|
.Pa /etc/ssh/sshd_config .
|
2000-02-18 19:02:22 +00:00
|
|
|
.Pp
|
2003-11-20 03:47:50 +00:00
|
|
|
To configure
|
2000-02-18 19:02:22 +00:00
|
|
|
.Xr sendmail 8 ,
|
2003-11-20 03:47:50 +00:00
|
|
|
it is necessary to modify
|
|
|
|
.Pa /etc/mail/sendmail.cf .
|
|
|
|
.Pp
|
|
|
|
For
|
2000-02-18 19:02:22 +00:00
|
|
|
.Xr named 8 ,
|
2003-11-20 03:47:50 +00:00
|
|
|
it is necessary to modify
|
|
|
|
.Pa /etc/namedb/named.conf .
|
|
|
|
.Pp
|
|
|
|
In addition, a number of services must be recompiled in order to run
|
|
|
|
them in the host environment.
|
|
|
|
This includes most applications providing services using
|
|
|
|
.Xr rpc 3 ,
|
|
|
|
such as
|
2005-01-21 20:48:00 +00:00
|
|
|
.Xr rpcbind 8 ,
|
2003-11-20 03:47:50 +00:00
|
|
|
.Xr nfsd 8 ,
|
2000-02-18 19:02:22 +00:00
|
|
|
and
|
2003-11-20 03:47:50 +00:00
|
|
|
.Xr mountd 8 .
|
|
|
|
In general, applications for which it is not possible to specify which
|
|
|
|
IP address to bind should not be run in the host environment unless they
|
|
|
|
should also service requests sent to jail IP addresses.
|
2001-09-03 15:42:10 +00:00
|
|
|
Attempting to serve
|
2000-02-18 19:02:22 +00:00
|
|
|
NFS from the host environment may also cause confusion, and cannot be
|
|
|
|
easily reconfigured to use only specific IPs, as some NFS services are
|
2001-12-14 10:18:15 +00:00
|
|
|
hosted directly from the kernel.
|
2004-05-20 06:37:44 +00:00
|
|
|
Any third-party network software running
|
2000-02-18 19:02:22 +00:00
|
|
|
in the host environment should also be checked and configured so that it
|
2004-05-20 06:37:44 +00:00
|
|
|
does not bind all IP addresses, which would result in those services' also
|
2000-02-18 19:02:22 +00:00
|
|
|
appearing to be offered by the jail environments.
|
|
|
|
.Pp
|
|
|
|
Once
|
|
|
|
these daemons have been disabled or fixed in the host environment, it is
|
|
|
|
best to reboot so that all daemons are in a known state, to reduce the
|
|
|
|
potential for confusion later (such as finding that when you send mail
|
|
|
|
to a jail, and its sendmail is down, the mail is delivered to the host,
|
2004-06-05 20:27:10 +00:00
|
|
|
etc.).
|
|
|
|
.Ss "Configuring the Jail"
|
2004-05-20 06:37:44 +00:00
|
|
|
Start any jail for the first time without configuring the network
|
2001-12-14 10:18:15 +00:00
|
|
|
interface so that you can clean it up a little and set up accounts.
|
|
|
|
As
|
2000-02-13 05:15:29 +00:00
|
|
|
with any machine (virtual or not) you will need to set a root password, time
|
2001-12-14 10:18:15 +00:00
|
|
|
zone, etc.
|
2003-11-20 03:47:50 +00:00
|
|
|
Some of these steps apply only if you intend to run a full virtual server
|
2004-05-20 06:37:44 +00:00
|
|
|
inside the jail; others apply both for constraining a particular application
|
|
|
|
or for running a virtual server.
|
2000-02-13 05:15:29 +00:00
|
|
|
.Pp
|
2003-11-20 02:46:44 +00:00
|
|
|
Start a shell in the jail:
|
2010-10-20 20:42:33 +00:00
|
|
|
.Pp
|
2009-05-27 14:30:26 +00:00
|
|
|
.Bd -literal -offset indent
|
2010-10-20 20:42:33 +00:00
|
|
|
jail -c path=/data/jail/testjail mount.devfs host.hostname=testhostname \\
|
2009-05-27 14:30:26 +00:00
|
|
|
ip4.addr=192.0.2.100 command=/bin/sh
|
|
|
|
.Ed
|
2001-12-14 10:18:15 +00:00
|
|
|
.Pp
|
2004-05-20 06:37:44 +00:00
|
|
|
Assuming no errors, you will end up with a shell prompt within the jail.
|
2001-12-14 10:18:15 +00:00
|
|
|
You can now run
|
2003-11-20 03:47:50 +00:00
|
|
|
.Pa /usr/sbin/sysinstall
|
2000-02-13 05:15:29 +00:00
|
|
|
and do the post-install configuration to set various configuration options,
|
2001-12-14 10:18:15 +00:00
|
|
|
or perform these actions manually by editing
|
|
|
|
.Pa /etc/rc.conf ,
|
|
|
|
etc.
|
2000-02-13 05:15:29 +00:00
|
|
|
.Pp
|
|
|
|
.Bl -bullet -offset indent -compact
|
|
|
|
.It
|
2005-07-25 16:04:30 +00:00
|
|
|
Configure
|
|
|
|
.Pa /etc/resolv.conf
|
|
|
|
so that name resolution within the jail will work correctly
|
|
|
|
.It
|
2000-02-20 02:51:11 +00:00
|
|
|
Run
|
|
|
|
.Xr newaliases 1
|
2001-12-14 10:18:15 +00:00
|
|
|
to quell
|
|
|
|
.Xr sendmail 8
|
|
|
|
warnings.
|
2000-02-20 02:51:11 +00:00
|
|
|
.It
|
2000-02-13 05:15:29 +00:00
|
|
|
Set a root password, probably different from the real host system
|
|
|
|
.It
|
|
|
|
Set the timezone
|
|
|
|
.It
|
|
|
|
Add accounts for users in the jail environment
|
|
|
|
.It
|
2003-11-20 03:47:50 +00:00
|
|
|
Install any packages the environment requires
|
2000-02-13 05:15:29 +00:00
|
|
|
.El
|
|
|
|
.Pp
|
2000-02-18 19:02:22 +00:00
|
|
|
You may also want to perform any package-specific configuration (web servers,
|
2001-12-14 10:18:15 +00:00
|
|
|
SSH servers, etc), patch up
|
|
|
|
.Pa /etc/syslog.conf
|
|
|
|
so it logs as you would like, etc.
|
2003-11-20 03:47:50 +00:00
|
|
|
If you are not using a virtual server, you may wish to modify
|
|
|
|
.Xr syslogd 8
|
|
|
|
in the host environment to listen on the syslog socket in the jail
|
|
|
|
environment; in this example, the syslog socket would be stored in
|
2010-10-20 20:42:33 +00:00
|
|
|
.Pa /data/jail/testjail/var/run/log .
|
2000-02-13 05:15:29 +00:00
|
|
|
.Pp
|
|
|
|
Exit from the shell, and the jail will be shut down.
|
2001-12-14 10:18:15 +00:00
|
|
|
.Ss "Starting the Jail"
|
2000-02-13 05:15:29 +00:00
|
|
|
You are now ready to restart the jail and bring up the environment with
|
2001-12-14 10:18:15 +00:00
|
|
|
all of its daemons and other programs.
|
2010-10-20 20:42:33 +00:00
|
|
|
Create an entry for the jail in
|
|
|
|
.Pa /etc/jail.conf :
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
testjail {
|
|
|
|
path = /tmp/jail/testjail;
|
|
|
|
mount.devfs;
|
|
|
|
host.hostname = testhostname;
|
|
|
|
ip4.addr = 192.0.2.100;
|
|
|
|
interface = ed0;
|
|
|
|
exec.start = "/bin/sh /etc/rc";
|
|
|
|
exec.stop = "/bin/sh /etc/rc.shutdown";
|
|
|
|
}
|
|
|
|
.Ed
|
|
|
|
.Pp
|
2003-11-20 03:47:50 +00:00
|
|
|
To start a virtual server environment,
|
|
|
|
.Pa /etc/rc
|
2010-10-20 20:42:33 +00:00
|
|
|
is run to launch various daemons and services, and
|
|
|
|
.Pa /etc/rc.shutdown
|
|
|
|
is run to shut them down when the jail is removed.
|
|
|
|
If you are running a single application in the jail,
|
|
|
|
substitute the command used to start the application for
|
|
|
|
.Dq /bin/sh /etc/rc ;
|
|
|
|
there may be some script available to cleanly shut down the application,
|
|
|
|
or it may be sufficient to go without a stop command, and have
|
|
|
|
.Nm
|
|
|
|
send
|
|
|
|
.Dv SIGTERM
|
|
|
|
to the application.
|
|
|
|
.Pp
|
|
|
|
Start the jail by running:
|
2000-02-13 05:15:29 +00:00
|
|
|
.Bd -literal -offset indent
|
2010-10-20 20:42:33 +00:00
|
|
|
jail -c testjail
|
2000-02-13 05:15:29 +00:00
|
|
|
.Ed
|
|
|
|
.Pp
|
2010-10-20 20:42:33 +00:00
|
|
|
A few warnings may be produced; however, it should all work properly.
|
2000-03-01 14:09:25 +00:00
|
|
|
You should be able to see
|
2000-02-13 05:15:29 +00:00
|
|
|
.Xr inetd 8 ,
|
|
|
|
.Xr syslogd 8 ,
|
|
|
|
and other processes running within the jail using
|
|
|
|
.Xr ps 1 ,
|
|
|
|
with the
|
2001-12-14 10:18:15 +00:00
|
|
|
.Ql J
|
|
|
|
flag appearing beside jailed processes.
|
2003-04-09 03:04:12 +00:00
|
|
|
To see an active list of jails, use the
|
|
|
|
.Xr jls 8
|
|
|
|
utility.
|
2001-12-14 10:18:15 +00:00
|
|
|
You should also be able to
|
|
|
|
.Xr telnet 1
|
|
|
|
to the hostname or IP address of the jailed environment, and log
|
2000-03-24 02:05:54 +00:00
|
|
|
in using the accounts you created previously.
|
2005-08-07 20:53:29 +00:00
|
|
|
.Pp
|
|
|
|
It is possible to have jails started at boot time.
|
|
|
|
Please refer to the
|
|
|
|
.Dq jail_*
|
|
|
|
variables in
|
|
|
|
.Xr rc.conf 5
|
|
|
|
for more information.
|
2001-12-14 10:18:15 +00:00
|
|
|
.Ss "Managing the Jail"
|
2000-02-13 05:15:29 +00:00
|
|
|
Normal machine shutdown commands, such as
|
|
|
|
.Xr halt 8 ,
|
|
|
|
.Xr reboot 8 ,
|
|
|
|
and
|
|
|
|
.Xr shutdown 8 ,
|
2001-12-14 10:18:15 +00:00
|
|
|
cannot be used successfully within the jail.
|
2010-10-20 20:42:33 +00:00
|
|
|
To kill all processes from within a jail, you may use one of the
|
|
|
|
following commands, depending on what you want to accomplish:
|
|
|
|
.Pp
|
2001-12-14 10:18:15 +00:00
|
|
|
.Bd -literal -offset indent
|
|
|
|
kill -TERM -1
|
|
|
|
kill -KILL -1
|
|
|
|
.Ed
|
2000-02-13 05:15:29 +00:00
|
|
|
.Pp
|
|
|
|
This will send the
|
2001-12-14 10:18:15 +00:00
|
|
|
.Dv SIGTERM
|
2000-02-13 05:15:29 +00:00
|
|
|
or
|
2001-12-14 10:18:15 +00:00
|
|
|
.Dv SIGKILL
|
2010-10-20 20:42:33 +00:00
|
|
|
signals to all processes in the jail - be careful not to run this from
|
|
|
|
the host environment!
|
|
|
|
Once all of the jail's processes have died, unless the jail was created
|
|
|
|
with the
|
|
|
|
.Va persist
|
|
|
|
parameter, the jail will be removed.
|
2001-12-14 10:18:15 +00:00
|
|
|
Depending on
|
2000-02-13 05:15:29 +00:00
|
|
|
the intended use of the jail, you may also want to run
|
|
|
|
.Pa /etc/rc.shutdown
|
2001-12-14 10:18:15 +00:00
|
|
|
from within the jail.
|
2010-10-20 20:42:33 +00:00
|
|
|
.Pp
|
|
|
|
To shut down the jail from the outside, simply remove it with
|
2009-05-27 14:30:26 +00:00
|
|
|
.Nm
|
|
|
|
.Ar -r ,
|
2010-10-20 20:42:33 +00:00
|
|
|
which will run any commands specified by
|
|
|
|
.Va exec.stop ,
|
|
|
|
and then send
|
|
|
|
.Dv SIGTERM
|
|
|
|
and eventually
|
|
|
|
.Dv SIGKILL
|
|
|
|
to any remaining jailed processes.
|
2000-02-13 05:15:29 +00:00
|
|
|
.Pp
|
2001-12-14 10:18:15 +00:00
|
|
|
The
|
|
|
|
.Pa /proc/ Ns Ar pid Ns Pa /status
|
2009-05-27 14:30:26 +00:00
|
|
|
file contains, as its last field, the name of the jail in which the
|
2000-02-13 05:15:29 +00:00
|
|
|
process runs, or
|
2001-12-14 10:18:15 +00:00
|
|
|
.Dq Li -
|
|
|
|
to indicate that the process is not running within a jail.
|
|
|
|
The
|
2000-02-13 05:15:29 +00:00
|
|
|
.Xr ps 1
|
|
|
|
command also shows a
|
2001-12-14 10:18:15 +00:00
|
|
|
.Ql J
|
|
|
|
flag for processes in a jail.
|
2005-05-28 16:23:29 +00:00
|
|
|
.Pp
|
|
|
|
You can also list/kill processes based on their jail ID.
|
2005-06-14 12:26:36 +00:00
|
|
|
To show processes and their jail ID, use the following command:
|
2005-05-28 16:23:29 +00:00
|
|
|
.Pp
|
2005-06-14 12:26:36 +00:00
|
|
|
.Dl "ps ax -o pid,jid,args"
|
2005-05-28 16:23:29 +00:00
|
|
|
.Pp
|
|
|
|
To show and then kill processes in jail number 3 use the following commands:
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
pgrep -lfj 3
|
|
|
|
pkill -j 3
|
|
|
|
.Ed
|
2005-06-14 12:26:36 +00:00
|
|
|
or:
|
2005-05-28 16:23:29 +00:00
|
|
|
.Pp
|
2005-06-14 12:26:36 +00:00
|
|
|
.Dl "killall -j 3"
|
2009-01-11 18:40:56 +00:00
|
|
|
.Ss "Jails and File Systems"
|
|
|
|
It is not possible to
|
|
|
|
.Xr mount 8
|
|
|
|
or
|
2009-01-17 14:52:26 +00:00
|
|
|
.Xr umount 8
|
2009-01-11 18:40:56 +00:00
|
|
|
any file system inside a jail unless the file system is marked
|
2009-05-27 14:30:26 +00:00
|
|
|
jail-friendly and the jail's
|
|
|
|
.Va allow.mount
|
|
|
|
parameter is set.
|
2009-01-11 18:40:56 +00:00
|
|
|
.Pp
|
|
|
|
Multiple jails sharing the same file system can influence each other.
|
|
|
|
For example a user in one jail can fill the file system also
|
|
|
|
leaving no space for processes in the other jail.
|
|
|
|
Trying to use
|
|
|
|
.Xr quota 1
|
|
|
|
to prevent this will not work either as the file system quotas
|
|
|
|
are not aware of jails but only look at the user and group IDs.
|
|
|
|
This means the same user ID in two jails share the same file
|
|
|
|
system quota.
|
2009-06-08 03:37:25 +00:00
|
|
|
One would need to use one file system per jail to make this work.
|
2001-12-14 10:18:15 +00:00
|
|
|
.Ss "Sysctl MIB Entries"
|
2009-05-27 14:30:26 +00:00
|
|
|
The read-only entry
|
2006-05-03 20:13:33 +00:00
|
|
|
.Va security.jail.jailed
|
2006-09-29 17:57:04 +00:00
|
|
|
can be used to determine if a process is running inside a jail (value
|
2006-05-03 20:13:33 +00:00
|
|
|
is one) or not (value is zero).
|
|
|
|
.Pp
|
2009-05-27 14:30:26 +00:00
|
|
|
The variable
|
|
|
|
.Va security.jail.max_af_ips
|
|
|
|
determines how may address per address family a prison may have.
|
|
|
|
The default is 255.
|
2006-05-08 19:55:17 +00:00
|
|
|
.Pp
|
2009-05-29 21:27:12 +00:00
|
|
|
Some MIB variables have per-jail settings.
|
2003-11-11 18:34:29 +00:00
|
|
|
Changes to these variables by a jailed process do not effect the host
|
|
|
|
environment, only the jail environment.
|
2009-05-29 21:27:12 +00:00
|
|
|
These variables are
|
|
|
|
.Va kern.securelevel ,
|
|
|
|
.Va kern.hostname ,
|
|
|
|
.Va kern.domainname ,
|
|
|
|
.Va kern.hostid ,
|
2003-11-11 18:34:29 +00:00
|
|
|
and
|
2009-05-29 21:27:12 +00:00
|
|
|
.Va kern.hostuuid .
|
2009-05-27 14:30:26 +00:00
|
|
|
.Ss "Hierarchical Jails"
|
|
|
|
By setting a jail's
|
2009-06-23 20:35:51 +00:00
|
|
|
.Va children.max
|
2009-05-27 14:30:26 +00:00
|
|
|
parameter, processes within a jail may be able to create jails of their own.
|
|
|
|
These child jails are kept in a hierarchy, with jails only able to see and/or
|
|
|
|
modify the jails they created (or those jails' children).
|
|
|
|
Each jail has a read-only
|
|
|
|
.Va parent
|
|
|
|
parameter, containing the
|
|
|
|
.Va jid
|
|
|
|
of the jail that created it; a
|
|
|
|
.Va jid
|
|
|
|
of 0 indicates the jail is a child of the current jail (or is a top-level
|
|
|
|
jail if the current process isn't jailed).
|
|
|
|
.Pp
|
|
|
|
Jailed processes are not allowed to confer greater permissions than they
|
|
|
|
themselves are given, e.g. if a jail is created with
|
|
|
|
.Va allow.nomount ,
|
|
|
|
it is not able to create a jail with
|
|
|
|
.Va allow.mount
|
|
|
|
set.
|
|
|
|
Similarly, such restrictions as
|
|
|
|
.Va ip4.addr
|
|
|
|
and
|
|
|
|
.Va securelevel
|
|
|
|
may not be bypassed in child jails.
|
|
|
|
.Pp
|
|
|
|
A child jail may in turn create its own child jails if its own
|
2009-06-23 20:35:51 +00:00
|
|
|
.Va children.max
|
|
|
|
parameter is set (remember it is zero by default).
|
2009-05-27 14:30:26 +00:00
|
|
|
These jails are visible to and can be modified by their parent and all
|
|
|
|
ancestors.
|
|
|
|
.Pp
|
|
|
|
Jail names reflect this hierarchy, with a full name being an MIB-type string
|
|
|
|
separated by dots.
|
|
|
|
For example, if a base system process creates a jail
|
|
|
|
.Dq foo ,
|
|
|
|
and a process under that jail creates another jail
|
|
|
|
.Dq bar ,
|
|
|
|
then the second jail will be seen as
|
|
|
|
.Dq foo.bar
|
|
|
|
in the base system (though it is only seen as
|
|
|
|
.Dq bar
|
|
|
|
to any processes inside jail
|
|
|
|
.Dq foo ) .
|
|
|
|
Jids on the other hand exist in a single space, and each jail must have a
|
|
|
|
unique jid.
|
|
|
|
.Pp
|
|
|
|
Like the names, a child jail's
|
|
|
|
.Va path
|
2010-10-20 20:42:33 +00:00
|
|
|
appears relative to its creator's own
|
2009-05-27 14:30:26 +00:00
|
|
|
.Va path .
|
|
|
|
This is by virtue of the child jail being created in the chrooted
|
|
|
|
environment of the first jail.
|
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/
1999-04-28 11:38:52 +00:00
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.Sh SEE ALSO
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2003-04-09 03:04:12 +00:00
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.Xr killall 1 ,
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2007-04-05 21:03:05 +00:00
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.Xr lsvfs 1 ,
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2000-02-20 02:51:11 +00:00
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.Xr newaliases 1 ,
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2005-05-28 16:23:29 +00:00
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.Xr pgrep 1 ,
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.Xr pkill 1 ,
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2000-02-20 02:51:11 +00:00
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.Xr ps 1 ,
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2009-01-11 18:40:56 +00:00
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.Xr quota 1 ,
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2009-05-27 14:30:26 +00:00
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.Xr jail_set 2 ,
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2010-10-20 20:42:33 +00:00
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.Xr jail.conf 5 ,
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2000-02-20 02:51:11 +00:00
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.Xr procfs 5 ,
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.Xr rc.conf 5 ,
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.Xr sysctl.conf 5 ,
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2010-10-20 20:42:33 +00:00
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.Xr chroot 8 ,
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2003-06-26 19:04:15 +00:00
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.Xr devfs 8 ,
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2000-02-20 02:51:11 +00:00
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.Xr halt 8 ,
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.Xr inetd 8 ,
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2003-04-09 03:04:12 +00:00
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.Xr jexec 8 ,
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.Xr jls 8 ,
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2006-11-21 23:45:44 +00:00
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.Xr mount 8 ,
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2000-02-20 02:51:11 +00:00
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.Xr named 8 ,
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.Xr reboot 8 ,
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2001-07-05 08:13:03 +00:00
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.Xr rpcbind 8 ,
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2000-02-20 02:51:11 +00:00
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.Xr sendmail 8 ,
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.Xr shutdown 8 ,
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.Xr sysctl 8 ,
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2009-01-12 07:45:03 +00:00
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.Xr syslogd 8 ,
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2009-01-17 14:52:26 +00:00
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.Xr umount 8
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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/
1999-04-28 11:38:52 +00:00
|
|
|
.Sh HISTORY
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The
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2001-08-27 12:15:44 +00:00
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.Nm
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2002-07-14 14:47:15 +00:00
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utility appeared in
|
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/
1999-04-28 11:38:52 +00:00
|
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.Fx 4.0 .
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2009-05-27 14:30:26 +00:00
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Hierarchical/extensible jails were introduced in
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.Fx 8.0 .
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1999-12-21 11:25:10 +00:00
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.Sh AUTHORS
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2001-12-14 10:18:15 +00:00
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.An -nosplit
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2000-03-24 02:05:54 +00:00
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The jail feature was written by
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.An Poul-Henning Kamp
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for R&D Associates
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2001-12-14 10:18:15 +00:00
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.Pa http://www.rndassociates.com/
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2000-11-14 11:20:58 +00:00
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who contributed it to
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.Fx .
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2000-02-20 02:51:11 +00:00
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.Pp
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2001-12-14 10:18:15 +00:00
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.An Robert Watson
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wrote the extended documentation, found a few bugs, added
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2000-02-16 23:50:43 +00:00
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a few new features, and cleaned up the userland jail environment.
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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
2008-11-29 14:32:14 +00:00
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.Pp
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.An Bjoern A. Zeeb
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added multi-IP jail support for IPv4 and IPv6 based on a patch
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originally done by
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.An Pawel Jakub Dawidek
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for IPv4.
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2009-05-27 14:30:26 +00:00
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.Pp
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.An James Gritton
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2010-10-20 20:42:33 +00:00
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added the extensible jail parameters, hierarchical jails,
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and the configuration file.
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2000-02-18 19:02:22 +00:00
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.Sh BUGS
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2010-10-20 20:42:33 +00:00
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It might be a good idea to add an
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2001-12-14 10:18:15 +00:00
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address alias flag such that daemons listening on all IPs
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.Pq Dv INADDR_ANY
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2000-02-18 19:02:22 +00:00
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will not bind on that address, which would facilitate building a safe
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host environment such that host daemons do not impose on services offered
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2001-12-14 10:18:15 +00:00
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from within jails.
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2004-05-20 06:37:44 +00:00
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Currently, the simplest answer is to minimize services
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2000-03-24 02:05:54 +00:00
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offered on the host, possibly limiting it to services offered from
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.Xr inetd 8
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2000-02-18 19:02:22 +00:00
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which is easily configurable.
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