Commit Graph

273 Commits

Author SHA1 Message Date
Jamie Gritton
babbbb9c57 Allow a jail's name to be the same as its jid (which is the default if no
name is specified), but still disallow other numeric names.

Reviewed by:	zec
Approved by:	bz (mentor)
MFC after:	3 days
2009-09-04 19:00:48 +00:00
Jamie Gritton
c4884ffa6f Fix a LOR between allprison_lock and vnode locks by releasing
allprison_lock before releasing a prison's root vnode.

PR:		kern/138004
Reviewed by:	kib
Approved by:	bz (mentor)
MFC after:	3 days
2009-08-27 16:15:51 +00:00
Marko Zec
0cb8b6a9b7 When "jail -c vnet" request fails, the current code actually creates and
leaves behind an orphaned vnet.  This change ensures that such vnets get
released.

This change affects only options VIMAGE builds.

Submitted by:	jamie
Discussed with:	bz
Approved by:	re (rwatson), julian (mentor)
MFC after:	3 days
2009-08-24 10:16:19 +00:00
Bjoern A. Zeeb
eb79e1c76e Make it possible to change the vnet sysctl variables on jails
with their own virtual network stack. Jails only inheriting a
network stack cannot change anything that cannot be changed from
within a prison.

Reviewed by:	rwatson, zec
Approved by:	re (kib)
2009-08-13 10:26:34 +00:00
Bjoern A. Zeeb
57aea6dfb8 Make the kernel compile without IP networking by moving
a variable under a proper #ifdef.

Approved by:	re (rwatson)
2009-08-12 12:12:23 +00:00
Robert Watson
530c006014 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00
Jamie Gritton
42bebd8205 Make the "enforce_statfs" default 2 (most restrictive) in jail_set(2),
instead of whatever the parent/system has (which is generally 0).  This
mirrors the old-style default used for jail(2) in conjunction with the
security.jail.enforce_statfs sysctl.

Approved by:	re (kib), bz (mentor)
2009-07-31 16:00:41 +00:00
Jamie Gritton
2b0d6f815e Remove a LOR, where the the sleepable allprison_lock was being obtained
in prison_equal_ip4/6 while an inp mutex was held.  Locking allprison_lock
can be avoided by making a restriction on the IP addresses associated with
jails:

Don't allow the "ip4" and "ip6" parameters to be changed after a jail is
created.  Setting the "ip4.addr" and "ip6.addr" parameters is allowed,
but only if the jail was already created with either ip4/6=new or
ip4/6=disable.  With this restriction, the prison flags in question
(PR_IP4_USER and PR_IP6_USER) become read-only and can be checked
without locking.

This also allows the simplification of a messy code path that was needed
to handle an existing prison gaining an IP address list.

PR:		kern/136899
Reported by:	Dirk Meyer
Approved by:	re (kib), bz (mentor)
2009-07-30 14:28:56 +00:00
Jamie Gritton
bdfc8cc4cd Don't allow mixing the "vnet" and "ip4/6" jail parameters, since vnet
jails have their own IP stack and don't have access to the parent IP
addresses anyway.  Note that a virtual network stack forms a break
between prisons with regard to the list of allowed IP addresses.

Approved by:	re (kib), bz (mentor)
2009-07-29 16:46:59 +00:00
Jamie Gritton
8986e3a023 Change the default value of the "ip4" and "ip6" jail parameters to
"disable", which only allows access to the parent/physical system's
IP addresses when specifically directed.  Change the default value of
"host" to "new", and don't copy the parent host values, to insulate
jails from the parent hostname et al.

Approved by:	re (kib), bz (mentor)
2009-07-29 16:41:02 +00:00
Jamie Gritton
7cbf72137f Some jail parameters (in particular, "ip4" and "ip6" for IP address
restrictions) were found to be inadequately described by a boolean.
Define a new parameter type with three values (disable, new, inherit)
to handle these and future cases.

Approved by:	re (kib), bz (mentor)
Discussed with:	rwatson
2009-07-25 14:48:57 +00:00
Jamie Gritton
7afcbc18b3 Remove the interim vimage containers, struct vimage and struct procg,
and the ioctl-based interface that supported them.

Approved by:	re (kib), bz (mentor)
2009-07-17 14:48:21 +00:00
Jamie Gritton
499650a033 Wrap a PR_VNET inside "#ifdef VIMAGE" since that the only place it applies.
bz wants the blame for this.

Noticed by:	rwatson
Approved by:	bz (mentor)
2009-06-24 22:06:56 +00:00
Jamie Gritton
6bb795633c In case of prisons with their own network stack, permit
additional privileges as well as not restricting the type of
sockets a user can open.

Note: the VIMAGE/vnet fetaure of of jails is still considered
      experimental and cannot guarantee that privileged users
      can be kept imprisoned if enabled.

Reviewed by:	rwatson
Approved by:	bz (mentor)
2009-06-24 21:39:50 +00:00
Jamie Gritton
b97457e2e6 Add a limit for child jails via the "children.cur" and "children.max"
parameters.  This replaces the simple "allow.jails" permission.

Approved by:	bz (mentor)
2009-06-23 20:35:51 +00:00
Jamie Gritton
679e13901c Manage vnets via the jail system. If a jail is given the boolean
parameter "vnet" when it is created, a new vnet instance will be created
along with the jail.  Networks interfaces can be moved between prisons
with an ioctl similar to the one that moves them between vimages.
For now vnets will co-exist under both jails and vimages, but soon
struct vimage will be going away.

Reviewed by:	zec, julian
Approved by:	bz (mentor)
2009-06-15 18:59:29 +00:00
Jamie Gritton
c1f192193d Rename the host-related prison fields to be the same as the host.*
parameters they represent, and the variables they replaced, instead of
abbreviated versions of them.

Approved by:	bz (mentor)
2009-06-13 15:39:12 +00:00
Jamie Gritton
7455b100af Add counterparts to getcredhostname:
getcreddomainname, getcredhostuuid, getcredhostid

Suggested by:	rmacklem
Approved by:	bz
2009-06-13 00:12:02 +00:00
Jamie Gritton
e92e0574f9 Fix some overflow errors: a signed allocation and an insufficiant
array size.

Reported by:	pho
Tested by:	pho
Approved by:	bz (mentor)
2009-06-09 22:09:29 +00:00
Robert Watson
bcf11e8d00 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
Jamie Gritton
76ca6f88da Place hostnames and similar information fully under the prison system.
The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex.  Jails may
have their own host information, or they may inherit it from the
parent/system.  The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL.  The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.

The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.

Approved by:	bz (mentor)
2009-05-29 21:27:12 +00:00
Jamie Gritton
0304c73163 Add hierarchical jails. A jail may further virtualize its environment
by creating a child jail, which is visible to that jail and to any
parent jails.  Child jails may be restricted more than their parents,
but never less.  Jail names reflect this hierarchy, being MIB-style
dot-separated strings.

Every thread now points to a jail, the default being prison0, which
contains information about the physical system.  Prison0's root
directory is the same as rootvnode; its hostname is the same as the
global hostname, and its securelevel replaces the global securelevel.
Note that the variable "securelevel" has actually gone away, which
should not cause any problems for code that properly uses
securelevel_gt() and securelevel_ge().

Some jail-related permissions that were kept in global variables and
set via sysctls are now per-jail settings.  The sysctls still exist for
backward compatibility, used only by the now-deprecated jail(2) system
call.

Approved by:	bz (mentor)
2009-05-27 14:11:23 +00:00
Jamie Gritton
1e2a13e62a Delay an error message until the variable it uses gets initialized.
Found with:	Coverity Prevent(tm)
CID:		4316
Reported by:	trasz
Approved by:	bz (mentor)
2009-05-23 16:13:26 +00:00
Marko Zec
29b02909eb Introduce a new virtualization container, provisionally named vprocg, to hold
virtualized instances of hostname and domainname, as well as a new top-level
virtualization struct vimage, which holds pointers to struct vnet and struct
vprocg.  Struct vprocg is likely to become replaced in the near future with
a new jail management API import.

As a consequence of this change, change struct ucred to point to a struct
vimage, instead of directly pointing to a vnet.

Merge vnet / vimage / ucred refcounting infrastructure from p4 / vimage
branch.

Permit kldload / kldunload operations to be executed only from the default
vimage context.

This change should have no functional impact on nooptions VIMAGE kernel
builds.

Reviewed by:	bz
Approved by:	julian (mentor)
2009-05-08 14:11:06 +00:00
Jamie Gritton
7ae27ff49f Move the per-prison Linux MIB from a private one-off pointer to the new
OSD-based jail extensions.  This allows the Linux MIB to accessed via
jail_set and jail_get, and serves as a demonstration of adding jail support
to a module.

Reviewed by:	dchagin, kib
Approved by:	bz (mentor)
2009-05-07 18:36:47 +00:00
Jamie Gritton
b38ff370e4 Introduce the extensible jail framework, using the same "name=value"
interface as nmount(2).  Three new system calls are added:
* jail_set, to create jails and change the parameters of existing jails.
  This replaces jail(2).
* jail_get, to read the parameters of existing jails.  This replaces the
  security.jail.list sysctl.
* jail_remove to kill off a jail's processes and remove the jail.
Most jail parameters may now be changed after creation, and jails may be
set to exist without any attached processes.  The current jail(2) system
call still exists, though it is now a stub to jail_set(2).

Approved by:	bz (mentor)
2009-04-29 21:14:15 +00:00
Jamie Gritton
af7bd9a4f4 Some non-functional changes: whitespace, KASSERT strings, declaration order.
Approved by:	bz (mentor)
2009-04-29 18:41:08 +00:00
Jamie Gritton
8571af59e5 Whitespace/spelling fixes in advance of upcoming functional changes.
Approved by:	bz (mentor)
2009-03-27 13:13:59 +00:00
Jamie Gritton
ca04ba6430 Don't allow creating a socket with a protocol family that the current
jail doesn't support.  This involves a new function prison_check_af,
like prison_check_ip[46] but that checks only the family.

With this change, most of the errors generated by jailed sockets
shouldn't ever occur, at least until jails are changeable.

Approved by:	bz (mentor)
2009-02-05 14:15:18 +00:00
Jamie Gritton
b89e82dd87 Standardize the various prison_foo_ip[46] functions and prison_if to
return zero on success and an error code otherwise.  The possible errors
are EADDRNOTAVAIL if an address being checked for doesn't match the
prison, and EAFNOSUPPORT if the prison doesn't have any addresses in
that address family.  For most callers of these functions, use the
returned error code instead of e.g. a hard-coded EADDRNOTAVAIL or
EINVAL.

Always include a jailed() check in these functions, where a non-jailed
cred always returns success (and makes no changes).  Remove the explicit
jailed() checks that preceded many of the function calls.

Approved by:	bz (mentor)
2009-02-05 14:06:09 +00:00
Ed Schouten
f3b86a5fd7 Mark most often used sysctl's as MPSAFE.
After running a `make buildkernel', I noticed most of the Giant locks in
sysctl are only caused by a very small amount of sysctl's:

- sysctl.name2oid. This one is locked by SYSCTL_LOCK, just like
  sysctl.oidfmt.

- kern.ident, kern.osrelease, kern.version, etc. These are just constant
  strings.

- kern.arandom, used by the stack protector. It is already protected by
  arc4_mtx.

I also saw the following sysctl's show up. Not as often as the ones
above, but still quite often:

- security.jail.jailed. Also mark security.jail.list as MPSAFE. They
  don't need locking or already use allprison_lock.

- kern.devname, used by devname(3), ttyname(3), etc.

This seems to reduce Giant locking inside sysctl by ~75% in my primitive
test setup.
2009-01-28 19:58:05 +00:00
Bjoern A. Zeeb
1cecba0fcd For consistency with prison_{local,remote,check}_ipN rename
prison_getipN to prison_get_ipN.

Submitted by:	jamie (as part of a larger patch)
MFC after:	1 week
2009-01-25 10:11:58 +00:00
Bjoern A. Zeeb
eb76156548 Back out r186615; the sanitizing of the pointers in the error case
is not needed and seems that it will not be needed either.

Pointy hat:	mine, mine, mine and not pho's
2009-01-04 12:18:18 +00:00
Peter Holm
1d347f061f Added missing second part of cleaning j->ip[46] as requested by bz
Approved by:	kib (mentor)
Pointy hat:	pho
2008-12-30 20:39:47 +00:00
Peter Holm
bc971b2c82 Make sure that unused j->ip[46] are cleared
Reviewed by:	bz
Approved by:	kib (mentor)
2008-12-30 17:54:25 +00:00
Bjoern A. Zeeb
0f1fe22db5 Correctly check the number of prison states to not access anything
outside the prison_states array.
When checking if there is a name configured for the prison, check the
first character to not be '\0' instead of checking if the char array
is present, which it always is. Note, that this is different for the
*jailname in the syscall.

Found with:	Coverity Prevent(tm)
CID:		4156, 4155
MFC after:	4 weeks (just that I get the mail)
2008-12-11 01:04:25 +00:00
Bjoern A. Zeeb
d465a41d3b Unbreak the no-networks (no INET/6) build that I broke with
the commit in r185435.

Pointyhat:	no, but I could need a ski cap for the winter
2008-11-29 16:17:39 +00:00
Bjoern A. Zeeb
413628a7e3 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
Bjoern A. Zeeb
b9f0b66c75 With the permissions of phk@ change the license on kern_jail.c
to a 2 clause BSD license.
2008-11-28 19:23:46 +00:00
Pawel Jakub Dawidek
1ba4a712dd Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes.
This bring huge amount of changes, I'll enumerate only user-visible changes:

- Delegated Administration

	Allows regular users to perform ZFS operations, like file system
	creation, snapshot creation, etc.

- L2ARC

	Level 2 cache for ZFS - allows to use additional disks for cache.
	Huge performance improvements mostly for random read of mostly
	static content.

- slog

	Allow to use additional disks for ZFS Intent Log to speed up
	operations like fsync(2).

- vfs.zfs.super_owner

	Allows regular users to perform privileged operations on files stored
	on ZFS file systems owned by him. Very careful with this one.

- chflags(2)

	Not all the flags are supported. This still needs work.

- ZFSBoot

	Support to boot off of ZFS pool. Not finished, AFAIK.

	Submitted by:	dfr

- Snapshot properties

- New failure modes

	Before if write requested failed, system paniced. Now one
	can select from one of three failure modes:
	- panic - panic on write error
	- wait - wait for disk to reappear
	- continue - serve read requests if possible, block write requests

- Refquota, refreservation properties

	Just quota and reservation properties, but don't count space consumed
	by children file systems, clones and snapshots.

- Sparse volumes

	ZVOLs that don't reserve space in the pool.

- External attributes

	Compatible with extattr(2).

- NFSv4-ACLs

	Not sure about the status, might not be complete yet.

	Submitted by:	trasz

- Creation-time properties

- Regression tests for zpool(8) command.

Obtained from:	OpenSolaris
2008-11-17 20:49:29 +00:00
Dag-Erling Smørgrav
1ede983cc9 Retire the MALLOC and FREE macros. They are an abomination unto style(9).
MFC after:	3 months
2008-10-23 15:53:51 +00:00
Marko Zec
8b615593fc Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by:	julian, bz, brooks, zec
Reviewed by:	julian, bz, brooks, kris, rwatson, ...
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-10-02 15:37:58 +00:00
Bjoern A. Zeeb
603724d3ab Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from:	//depot/projects/vimage-commit2/...
Reviewed by:	brooks, des, ed, mav, julian,
		jamie, kris, rwatson, zec, ...
		(various people I forgot, different versions)
		md5 (with a bit of help)
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
X-MFC after:	never
V_Commit_Message_Reviewed_By:	more people than the patch
2008-08-17 23:27:27 +00:00
Bjoern A. Zeeb
45e48455cd MFp4 144659:
Plug a memory leak with jail services.

PR:		125257
Submitted by:	Mateusz Guzik <mjguzik gmail.com>
MFC after:	6 days
2008-07-07 20:53:49 +00:00
Robert Watson
4f7d1876d5 Introduce a new lock, hostname_mtx, and use it to synchronize access
to global hostname and domainname variables.  Where necessary, copy
to or from a stack-local buffer before performing copyin() or
copyout().  A few uses, such as in cd9660 and daemon_saver, remain
under-synchronized and will require further updates.

Correct a bug in which a failed copyin() of domainname would leave
domainname potentially corrupted.

MFC after:	3 weeks
2008-07-05 13:10:10 +00:00
Xin LI
2110d913c0 Revert rev. 178124 as requested by kris@. Having jail id not being
reused too frequently is useful for script controlled environment.
2008-06-19 21:41:57 +00:00
Xin LI
31c50f53da Instead of rolling our own jail number allocation procedure, use
alloc_unr() to do it.

Submitted by:	Ed Schouten <ed 80386 nl>
PR:		kern/122270
MFC after:	1 month
2008-04-11 21:31:15 +00:00
Konstantin Belousov
57b4252e45 Add the support for the AT_FDCWD and fd-relative name lookups to the
namei(9).

Based on the submission by rdivacky,
	sponsored by Google Summer of Code 2007
Reviewed by:	rwatson, rdivacky
Tested by:	pho
2008-03-31 12:01:21 +00:00
Bjoern A. Zeeb
79ba395267 Replace the last susers calls in netinet6/ with privilege checks.
Introduce a new privilege allowing to set certain IP header options
(hop-by-hop, routing headers).

Leave a few comments to be addressed later.

Reviewed by:	rwatson (older version, before addressing his comments)
2008-01-24 08:25:59 +00:00
Attilio Rao
22db15c06f VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
Attilio Rao
cb05b60a89 vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by:	Diego Sardina <siarodx at gmail dot com>,
		Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
Robert Watson
30d239bc4c Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

  mac_<object>_<method/action>
  mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme.  Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier.  Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods.  Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by:	SPARTA (original patches against Mac OS X)
Obtained from:	TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
Robert Watson
e41966dc35 Add PRIV_VFS_STAT privilege, which will allow overriding policy limits on
the right to stat() a file, such as in mac_bsdextended.

Obtained from:	TrustedBSD Project
MFC after:	3 months
2007-10-21 22:50:11 +00:00
Pawel Jakub Dawidek
24b0502ee0 Fix jails and jail-friendly file systems handling:
- We need to allow for PRIV_VFS_MOUNT_OWNER inside a jail.
- Move security checks to vfs_suser() and deny unmounting and updating
  for jailed root from different jails, etc.

OK'ed by:	rwatson
2007-04-13 23:54:22 +00:00
Robert Watson
4b08405682 Allow PRIV_NETINET_REUSEPORT in jail. 2007-04-10 15:59:49 +00:00
Pawel Jakub Dawidek
c2cda60911 prison_free() can be called with a mutex held. This wasn't a problem until
I converted allprison_mtx mutex to allprison_lock sx lock. To fix this LOR,
move prison removal to prison_complete() entirely. To ensure that noone
will reference this prison before it's beeing removed from the list skip
prisons with 'pr_ref == 0' in prison_find() and assert that pr_ref has to
greater than 0 in prison_hold().

Reported by:	kris
OK'ed by:	rwatson
2007-04-08 10:46:23 +00:00
Pawel Jakub Dawidek
b63b0c6529 Only use prison mutex to protect the fields that need to be protected by it. 2007-04-08 10:21:38 +00:00
Pawel Jakub Dawidek
264de85e73 pr_list is protected by the allprison_lock. 2007-04-08 02:13:32 +00:00
Pawel Jakub Dawidek
dc68a63332 Implement functionality I called 'jail services'.
It may be used for external modules to attach some data to jail's in-kernel
structure.

- Change allprison_mtx mutex to allprison_sx sx(9) lock.
  We will need to call external functions while holding this lock, which may
  want to allocate memory.
  Make use of the fact that this is shared-exclusive lock and use shared
  version when possible.
- Implement the following functions:
  prison_service_register() - registers a service that wants to be noticed
	when a jail is created and destroyed
  prison_service_deregister() - deregisters service
  prison_service_data_add() - adds service-specific data to the jail structure
  prison_service_data_get() - takes service-specific data from the jail
	structure
  prison_service_data_del() - removes service-specific data from the jail
	structure

Reviewed by:	rwatson
2007-04-05 23:19:13 +00:00
Pawel Jakub Dawidek
54b369c1ae Make prison_find() globally accessible. 2007-04-05 21:34:54 +00:00
Pawel Jakub Dawidek
f3a8d2f93c Add security.jail.mount_allowed sysctl, which allows to mount and
unmount jail-friendly file systems from within a jail.
Precisely it grants PRIV_VFS_MOUNT, PRIV_VFS_UNMOUNT and
PRIV_VFS_MOUNT_NONUSER privileges for a jailed super-user.
It is turned off by default.

A jail-friendly file system is a file system which driver registers
itself with VFCF_JAIL flag via VFS_SET(9) API.
The lsvfs(1) command can be used to see which file systems are
jail-friendly ones.

There currently no jail-friendly file systems, ZFS will be the first one.
In the future we may consider marking file systems like nullfs as
jail-friendly.

Reviewed by:	rwatson
2007-04-05 21:03:05 +00:00
Pawel Jakub Dawidek
2709e8904f Minor simplification. 2007-03-09 05:22:10 +00:00
Pawel Jakub Dawidek
9e5dcf7b21 White space nits. 2007-03-07 21:24:51 +00:00
Robert Watson
0c14ff0eb5 Remove 'MPSAFE' annotations from the comments above most system calls: all
system calls now enter without Giant held, and then in some cases, acquire
Giant explicitly.

Remove a number of other MPSAFE annotations in the credential code and
tweak one or two other adjacent comments.
2007-03-04 22:36:48 +00:00
Pawel Jakub Dawidek
bb531912ff Rename PRIV_VFS_CLEARSUGID to PRIV_VFS_RETAINSUGID, which seems to better
describe the privilege.

OK'ed by:	rwatson
2007-03-01 20:47:42 +00:00
Robert Watson
95420afea4 Remove unused PRIV_IPC_EXEC. Renumbers System V IPC privilege. 2007-02-20 00:12:52 +00:00
Robert Watson
95b091d2f2 Rename three quota privileges from the UFS privilege namespace to the
VFS privilege namespace: exceedquota, getquota, and setquota.  Leave
UFS-specific quota configuration privileges in the UFS name space.

This renumbers VFS and UFS privileges, so requires rebuilding modules
if you are using security policies aware of privilege identifiers.
This is likely no one at this point since none of the committed MAC
policies use the privilege checks.
2007-02-19 13:33:10 +00:00
Robert Watson
e82d0201bd Limit quota privileges in jail to PRIV_UFS_GETQUOTA and
PRIV_UFS_SETQUOTA.
2007-02-19 13:26:39 +00:00
Robert Watson
c3c1b5e62a For now, reflect practical reality that Audit system calls aren't
allowed in Jail: return a privilege error.
2007-02-19 13:10:29 +00:00
Robert Watson
800c940832 Add a new priv(9) kernel interface for checking the availability of
privilege for threads and credentials.  Unlike the existing suser(9)
interface, priv(9) exposes a named privilege identifier to the privilege
checking code, allowing more complex policies regarding the granting of
privilege to be expressed.  Two interfaces are provided, replacing the
existing suser(9) interface:

suser(td)                 ->   priv_check(td, priv)
suser_cred(cred, flags)   ->   priv_check_cred(cred, priv, flags)

A comprehensive list of currently available kernel privileges may be
found in priv.h.  New privileges are easily added as required, but the
comments on adding privileges found in priv.h and priv(9) should be read
before doing so.

The new privilege interface exposed sufficient information to the
privilege checking routine that it will now be possible for jail to
determine whether a particular privilege is granted in the check routine,
rather than relying on hints from the calling context via the
SUSER_ALLOWJAIL flag.  For now, the flag is maintained, but a new jail
check function, prison_priv_check(), is exposed from kern_jail.c and used
by the privilege check routine to determine if the privilege is permitted
in jail.  As a result, a centralized list of privileges permitted in jail
is now present in kern_jail.c.

The MAC Framework is now also able to instrument privilege checks, both
to deny privileges otherwise granted (mac_priv_check()), and to grant
privileges otherwise denied (mac_priv_grant()), permitting MAC Policy
modules to implement privilege models, as well as control a much broader
range of system behavior in order to constrain processes running with
root privilege.

The suser() and suser_cred() functions remain implemented, now in terms
of priv_check() and the PRIV_ROOT privilege, for use during the transition
and possibly continuing use by third party kernel modules that have not
been updated.  The PRIV_DRIVER privilege exists to allow device drivers to
check privilege without adopting a more specific privilege identifier.

This change does not modify the actual security policy, rather, it
modifies the interface for privilege checks so changes to the security
policy become more feasible.

Sponsored by:		nCircle Network Security, Inc.
Obtained from:		TrustedBSD Project
Discussed on:		arch@
Reviewed (at least in part) by:	mlaier, jmg, pjd, bde, ceri,
			Alex Lyashkov <umka at sevcity dot net>,
			Skip Ford <skip dot ford at verizon dot net>,
			Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:37:19 +00:00
Robert Watson
aed5570872 Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h.  sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA
2006-10-22 11:52:19 +00:00
Robert Watson
5702e0965e Declare security and security.bsd sysctl hierarchies in sysctl.h along
with other commonly used sysctl name spaces, rather than declaring them
all over the place.

MFC after:	1 month
Sponsored by:	nCircle Network Security, Inc.
2006-09-17 20:00:36 +00:00
Christian S.J. Peron
453f7d5369 Push Giant down in jails. Pass the MPSAFE flag to NDINIT, and keep track
of whether or not Giant was picked up by the filesystem. Add VFS_LOCK_GIANT
macros around vrele as it's possible that this can call in the VOP_INACTIVE
filesystem specific code. Also while we are here, remove the Giant assertion.
from the sysctl handler,  we do not actually require Giant here so we
shouldn't assert it. Doing so will just complicate things when Giant is removed
from the sysctl framework.
2005-09-28 00:30:56 +00:00
Pawel Jakub Dawidek
06a137780b Actually only protect mount-point if security.jail.enforce_statfs is set to 2.
If we don't return statistics about requested file systems, system tools
may not work correctly or at all.

Approved by:	re (scottl)
2005-06-23 22:13:29 +00:00
Pawel Jakub Dawidek
820a0de9a9 Rename sysctl security.jail.getfsstatroot_only to security.jail.enforce_statfs
and extend its functionality:

value	policy
0	show all mount-points without any restrictions
1	show only mount-points below jail's chroot and show only part of the
	mount-point's path (if jail's chroot directory is /jails/foo and
	mount-point is /jails/foo/usr/home only /usr/home will be shown)
2	show only mount-point where jail's chroot directory is placed.

Default value is 2.

Discussed with:	rwatson
2005-06-09 18:49:19 +00:00
Jeff Roberson
22fdc83f93 - Use taskqueue_thread rather than taskqueue_swi since our task is going
to vrele, which may vop lock.  This is not safe in a software interrupt
   context.
2005-04-05 08:51:45 +00:00
John Baldwin
2945387fee Drop a bogus mp_fixme(). Adding a lock would do nothing to reduce userland
races regarding changing of jail-related sysctls.
2005-03-31 22:47:57 +00:00
Colin Percival
79653046d8 Add a new sysctl, "security.jail.chflags_allowed", which controls the
behaviour of chflags within a jail.  If set to 0 (the default), then a
jailed root user is treated as an unprivileged user; if set to 1, then
a jailed root user is treated the same as an unjailed root user.

This is necessary to allow "make installworld" to work inside a jail,
since it attempts to manipulate the system immutable flag on certain
files.

Discussed with:	csjp, rwatson
MFC after:	2 weeks
2005-02-08 21:31:11 +00:00
Warner Losh
9454b2d864 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
Pawel Jakub Dawidek
46e3b1cbe7 Add two missing includes and remove two uneeded.
This is quite serious fix, because even with MAC framework compiled in,
MAC entry points in those two files were simply ignored.
2004-06-27 09:03:22 +00:00
Pawel Jakub Dawidek
2ff8a3496f Fix sysctl name: security.jail.getfsstate_getfsstatroot_only ->
security.jail.getfsstatroot_only.

Approved by:	rwatson
2004-05-20 05:28:44 +00:00
Bosko Milekic
5a59cefcd1 Give jail(8) the feature to allow raw sockets from within a
jail, which is less restrictive but allows for more flexible
jail usage (for those who are willing to make the sacrifice).
The default is off, but allowing raw sockets within jails can
now be accomplished by tuning security.jail.allow_raw_sockets
to 1.

Turning this on will allow you to use things like ping(8)
or traceroute(8) from within a jail.

The patch being committed is not identical to the patch
in the PR.  The committed version is more friendly to
APIs which pjd is working on, so it should integrate
into his work quite nicely.  This change has also been
presented and addressed on the freebsd-hackers mailing
list.

Submitted by: Christian S.J. Peron <maneo@bsdpro.com>
PR: kern/65800
2004-04-26 19:46:52 +00:00
Pawel Jakub Dawidek
7f4704c01d Remove sysctl security.jail.list_allowed.
This functionality was a misfeature, sysctl was added and turned off by
default just to check if nobody complains.

Reviewed by:	rwatson
2004-03-15 12:10:34 +00:00
Jacques Vidrine
57f22bd4af Rework jail_attach(2) so that an already jailed process cannot hop
to another jail.

Submitted by:	rwatson
2004-02-19 21:03:20 +00:00
Pawel Jakub Dawidek
461167c289 Added sysctl security.jail.jailed.
It returns 1 is process is inside of jail and 0 if it is not.
Information if we are in jail or not is not a secret, there is plenty of
ways to discover it. Many people are using own hack to check this and
this will be a legal way from now on.

It will be great if our starting scripts will take advantage of this sysctl
to allow clean "boot" inside jail.

Approved by:	rwatson, scottl (mentor)
2004-02-19 14:29:14 +00:00
Robert Watson
679a106075 By default, don't allow processes in a jail to list the set of
jails in the system.  Previous behavior (allowed) may be restored
by setting security.jail.list_allowed=1.
2004-02-14 19:19:47 +00:00
Robert Watson
7e440242e5 Fix mismerge in last commit: check that cred->cr_prison is NULL
before dereferencing the prison pointer.
2004-02-14 18:52:43 +00:00
Robert Watson
f08df373a3 By default, when a process in jail calls getfsstat(), only return the
data for the file system on which the jail's root vnode is located.
Previous behavior (show data for all mountpoints) can be restored
by setting security.jail.getfsstatroot_only to 0.  Note: this also
has the effect of hiding other mounts inside a jail, such as /dev,
/tmp, and /proc, but errs on the side of leaking less information.
2004-02-14 18:31:11 +00:00
Robert Watson
b3059e09f6 Defer the vrele() on a jail's root vnode reference from prison_free()
to a new prison_complete() task run by a task queue.  This removes
a requirement for grabbing Giant in crfree().  Embed the 'struct task'
in 'struct prison' so that we don't have to allocate memory from
prison_free() (which means we also defer the FREE()).

With this change, I believe grabbing Giant from crfree() can now be
removed, but need to check the uidinfo code paths.

To avoid header pollution, move the definition of 'struct task'
to _task.h, and recursively include from taskqueue.h and jail.h; much
preferably to all files including jail.h picking up a requirement to
include taskqueue.h.

Bumped into by:	sam
Reviewed by:	bde, tjr
2004-01-23 20:44:26 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
Mike Barcroft
9ddb795450 style(9) 2003-04-28 18:32:19 +00:00
John Baldwin
69c4ee54ff - The prison mutex cannot possibly protect pointers to the prison it
protects, so don't bother locking it while we assign it to a ucred's
  cr_prison.
- Fully construct the new credential for a process before assigning it to
  p_ucred.
2003-04-17 22:26:53 +00:00
Mike Barcroft
fd7a8150fb o In struct prison, add an allprison linked list of prisons (protected
by allprison_mtx), a unique prison/jail identifier field, two path
  fields (pr_path for reporting and pr_root vnode instance) to store
  the chroot() point of each jail.
o Add jail_attach(2) to allow a process to bind to an existing jail.
o Add change_root() to perform the chroot operation on a specified
  vnode.
o Generalize change_dir() to accept a vnode, and move namei() calls
  to callers of change_dir().
o Add a new sysctl (security.jail.list) which is a group of
  struct xprison instances that represent a snapshot of active jails.

Reviewed by:	rwatson, tjr
2003-04-09 02:55:18 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Maxime Henrion
894db7b01f Don't forget to destroy the mutex if an error occurs
in the jail() system call.

Submitted by:	Pawel Jakub Dawidek <nick@garage.freebsd.pl>
2002-12-20 14:32:20 +00:00
Alfred Perlstein
b80521fee5 remove syscallarg().
Suggested by: peter
2002-12-14 02:07:32 +00:00
Robert Drehmel
e80fb43467 Use strlcpy() instead of strncpy() to copy NUL terminated strings
for safety and consistency.
2002-10-17 20:03:38 +00:00
Ian Dowse
f2f2285a6a The jail syscall calls chroot, which is not mpsafe, so put back a
mtx_lock(&Giant) around that call.

Reviewed by:	arr
2002-07-01 20:46:01 +00:00
Andrew R. Reiter
4e77f68011 - Alleviate jail() from having the burden of acquiring Giant by simply
removing.  We can do this since we no longer need Giant to safely
  execute jail().

Reviewed by:	rwatson, jhb
2002-06-26 00:29:01 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00
John Baldwin
44731cab3b Change the suser() API to take advantage of td_ucred as well as do a
general cleanup of the API.  The entire API now consists of two functions
similar to the pre-KSE API.  The suser() function takes a thread pointer
as its only argument.  The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0.  The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.

Discussed on:	smp@
2002-04-01 21:31:13 +00:00
Robert Drehmel
ad1ff0997e Make getcredhostname() take a buffer and the buffer's size
as arguments.  The correct hostname is copied into the buffer
while having the prison's lock acquired in a jailed process'
case.

Reviewed by:	jhb, rwatson
2002-02-27 16:43:20 +00:00
Robert Drehmel
9484d0c0e8 Add a function which returns the correct hostname for a given
credential.

Reviewed by:	phk
2002-02-27 14:58:32 +00:00
Andrew R. Reiter
d0615c64a5 - Attempt to help declutter kern. sysctl by moving security out from
beneath it.

Reviewed by: rwatson
2002-01-16 06:55:30 +00:00
Andrew R. Reiter
83aee5a8d5 - Move _jail sysctl node underneath _kern_security in order to standardize
where our security related sysctl tuneables are located.  Also, this
  will help if/when we move _security node out from under _kern as to help
  make _kern less cluttered.

Approved by:	rwatson
Review by:	rwatson
2001-12-12 05:23:20 +00:00
Robert Watson
011376308f o Introduce pr_mtx into struct prison, providing protection for the
mutable contents of struct prison (hostname, securelevel, refcount,
  pr_linux, ...)
o Generally introduce mtx_lock()/mtx_unlock() calls throughout kern/
  so as to enforce these protections, in particular, in kern_mib.c
  protection sysctl access to the hostname and securelevel, as well as
  kern_prot.c access to the securelevel for access control purposes.
o Rewrite linux emulator abstractions for accessing per-jail linux
  mib entries (osname, osrelease, osversion) so that they don't return
  a pointer to the text in the struct linux_prison, rather, a copy
  to an array passed into the calls.  Likewise, update linprocfs to
  use these primitives.
o Update in_pcb.c to always use prison_getip() rather than directly
  accessing struct prison.

Reviewed by:	jhb
2001-12-03 16:12:27 +00:00
Robert Watson
fc5d29ef7d o Move suser() calls in kern/ to using suser_xxx() with an explicit
credential selection, rather than reference via a thread or process
  pointer.  This is part of a gradual migration to suser() accepting
  a struct ucred instead of a struct proc, simplifying the reference
  and locking semantics of suser().

Obtained from:	TrustedBSD Project
2001-11-01 20:56:57 +00:00
John Baldwin
a2f2b3afcd - Catch up to the new ucred API.
- Add proc locking to the jail() syscall.  This mostly involved shuffling
  a few things around so that blockable things like malloc and copyin
  were performed before acquiring the lock and checking the existing
  ucred and then updating the ucred as one "atomic" change under the proc
  lock.
2001-10-11 23:39:43 +00:00
Robert Watson
567931c8f6 o Initialize per-jail securelevel from global securelevel as part of
jail creation.

Obtained from:	TrustedBSD Project
2001-09-26 20:37:15 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
Matthew Dillon
116734c4d1 Pushdown Giant for acct(), kqueue(), kevent(), execve(), fork(),
vfork(), rfork(), jail().
2001-09-01 03:04:31 +00:00
Robert Watson
fd6aaf7fe1 Anton kindly pointed out (and fixed) a bug in the Jail handling of the
bind() call on IPv4 sockets:

  Currently, if one tries to bind a socket using INADDR_LOOPBACK inside a
  jail, it will fail because prison_ip() does not take this possibility
  into account.  On the other hand, when one tries to connect(), for
  example, to localhost, prison_remote_ip() will silently convert
  INADDR_LOOPBACK to the jail's IP address.  Therefore, it is desirable to
  make bind() to do this implicit conversion as well.

  Apart from this, the patch also replaces 0x7f000001 in
  prison_remote_ip() to a more correct INADDR_LOOPBACK.

This is a 4.4-RELEASE "during the freeze, thanks" MFC candidate.

Submitted by:	Anton Berezin <tobez@FreeBSD.org>
Discussed with at some point:	phk
MFC after:	3 days
2001-08-03 18:21:06 +00:00
Robert Watson
91421ba234 o Move per-process jail pointer (p->pr_prison) to inside of the subject
credential structure, ucred (cr->cr_prison).
o Allow jail inheritence to be a function of credential inheritence.
o Abstract prison structure reference counting behind pr_hold() and
  pr_free(), invoked by the similarly named credential reference
  management functions, removing this code from per-ABI fork/exit code.
o Modify various jail() functions to use struct ucred arguments instead
  of struct proc arguments.
o Introduce jailed() function to determine if a credential is jailed,
  rather than directly checking pointers all over the place.
o Convert PRISON_CHECK() macro to prison_check() function.
o Move jail() function prototypes to jail.h.
o Emulate the P_JAILED flag in fill_kinfo_proc() and no longer set the
  flag in the process flags field itself.
o Eliminate that "const" qualifier from suser/p_can/etc to reflect
  mutex use.

Notes:

o Some further cleanup of the linux/jail code is still required.
o It's now possible to consider resolving some of the process vs
  credential based permission checking confusion in the socket code.
o Mutex protection of struct prison is still not present, and is
  required to protect the reference count plus some fields in the
  structure.

Reviewed by:	freebsd-arch
Obtained from:	TrustedBSD Project
2001-02-21 06:39:57 +00:00
David Malone
7cc0979fd6 Convert more malloc+bzero to malloc+M_ZERO.
Submitted by:	josh@zipperup.org
Submitted by:	Robert Drehmel <robd@gmx.net>
2000-12-08 21:51:06 +00:00
Robert Watson
cb1f0db9db o Deny access to System V IPC from within jail by default, as in the
current implementation, jail neither virtualizes the Sys V IPC namespace,
  nor provides inter-jail protections on IPC objects.
o Support for System V IPC can be enabled by setting jail.sysvipc_allowed=1
  using sysctl.
o This is not the "real fix" which involves virtualizing the System V
  IPC namespace, but prevents processes within jail from influencing those
  outside of jail when not approved by the administrator.

Reported by:	Paulo Fragoso <paulo@nlink.com.br>
2000-10-31 01:34:00 +00:00
Robert Watson
7cadc2663e o Modify jail to limit creation of sockets to UNIX domain sockets,
TCP/IP (v4) sockets, and routing sockets.  Previously, interaction
  with IPv6 was not well-defined, and might be inappropriate for some
  environments.  Similarly, sysctl MIB entries providing interface
  information also give out only addresses from those protocol domains.

  For the time being, this functionality is enabled by default, and
  toggleable using the sysctl variable jail.socket_unixiproute_only.
  In the future, protocol domains will be able to determine whether or
  not they are ``jail aware''.

o Further limitations on process use of getpriority() and setpriority()
  by jailed processes.  Addresses problem described in kern/17878.

Reviewed by:	phk, jmg
2000-06-04 04:28:31 +00:00
Robert Watson
83f1e257e0 Yet-another-update: rename ``kern.prison'' to a new sysctl root entry,
``jail'', and move the set_hostname_allowed sysctl there, as well as
fixing a bug in the sysctl that resulted in jails being over-limited
(preventing them from reading as well as writing the hostname).  Also,
correct some formatting issues, courtesy bde :-).

Reviewed by:	phk
Approved by:	jkh
2000-02-12 13:41:56 +00:00
Poul-Henning Kamp
978f8d9300 Add a version number field to the jail(2) argument so that future changes
can be handled intelligently.
1999-09-19 08:36:03 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Poul-Henning Kamp
07901f227b Add beer-ware license and $Id$
Noticed by:	dillon
1999-04-30 06:51:51 +00:00
Poul-Henning Kamp
430210c00b Make BOOTP to work again.
Submitted by:	dillon
Reviewed by:	phk
1999-04-30 06:30:15 +00:00
Poul-Henning Kamp
75c1354190 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