Commit Graph

66 Commits

Author SHA1 Message Date
Robert Watson
2220907b6e Introduce a temporary mutex, mac_ifnet_mtx, to lock MAC labels on
network interfaces.  This global mutex will protect all ifnet labels.
Acquire the mutex across various MAC activities on interfaces, such
as security checks, propagating interface labels to mbufs generated
from the interface, retrieving and setting the interface label.

Introduce mpo_copy_ifnet_label MAC policy entry point to copy the
value of an interface label from one label to another.  Use this
to avoid performing a label externalize while holding mac_ifnet_mtx;
copy the label to a temporary ifnet label and then externalize that.

Implement mpo_copy_ifnet_label for various MAC policies that
implement interface labeling using generic label copying routines.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, McAfee Research
2004-06-24 03:34:46 +00:00
Poul-Henning Kamp
89c9c53da0 Do the dreaded s/dev_t/struct cdev */
Bump __FreeBSD_version accordingly.
2004-06-16 09:47:26 +00:00
Robert Watson
f6a4109212 Update my personal copyrights and NETA copyrights in the kernel
to use the "year1-year3" format, as opposed to "year1, year2, year3".
This seems to make lawyers more happy, but also prevents the
lines from getting excessively long as the years start to add up.

Suggested by:	imp
2004-02-22 00:33:12 +00:00
Robert Watson
4795b82c13 Coalesce pipe allocations and frees. Previously, the pipe code
would allocate two 'struct pipe's from the pipe zone, and malloc a
mutex.

- Create a new "struct pipepair" object holding the two 'struct
  pipe' instances, struct mutex, and struct label reference.  Pipe
  structures now have a back-pointer to the pipe pair, and a
  'pipe_present' flag to indicate whether the half has been
  closed.

- Perform mutex init/destroy in zone init/destroy, avoiding
  reallocating the mutex for each pipe.  Perform most pipe structure
  setup in zone constructor.

- VM memory mappings for pageable buffers are still done outside of
  the UMA zone.

- Change MAC API to speak 'struct pipepair' instead of 'struct pipe',
  update many policies.  MAC labels are also handled outside of the
  UMA zone for now.  Label-only policy modules don't have to be
  recompiled, but if a module is recompiled, its pipe entry points
  will need to be updated.  If a module actually reached into the
  pipe structures (unlikely), that would also need to be modified.

These changes substantially simplify failure handling in the pipe
code as there are many fewer possible failure modes.

On half-close, pipes no longer free the 'struct pipe' for the closed
half until a full-close takes place.  However, VM mapped buffers
are still released on half-close.

Some code refactoring is now possible to clean up some of the back
references, etc; this patch attempts not to change the structure
of most of the pipe implementation, only allocation/free code
paths, so as to avoid introducing bugs (hopefully).

This cuts about 8%-9% off the cost of sequential pipe allocation
and free in system call tests on UP and SMP in my micro-benchmarks.
May or may not make a difference in macro-benchmarks, but doing
less work is good.

Reviewed by:	juli, tjr
Testing help:	dwhite, fenestro, scottl, et al
2004-02-01 05:56:51 +00:00
Robert Watson
2d92ec9858 Switch TCP over to using the inpcb label when responding in timed
wait, rather than the socket label.  This avoids reaching up to
the socket layer during connection close, which requires locking
changes.  To do this, introduce MAC Framework entry point
mac_create_mbuf_from_inpcb(), which is called from tcp_twrespond()
instead of calling mac_create_mbuf_from_socket() or
mac_create_mbuf_netlayer().  Introduce MAC Policy entry point
mpo_create_mbuf_from_inpcb(), and implementations for various
policies, which generally just copy label data from the inpcb to
the mbuf.  Assert the inpcb lock in the entry point since we
require consistency for the inpcb label reference.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-12-17 14:55:11 +00:00
Robert Watson
56d9e93207 Rename mac_create_cred() MAC Framework entry point to mac_copy_cred(),
and the mpo_create_cred() MAC policy entry point to
mpo_copy_cred_label().  This is more consistent with similar entry
points for creation and label copying, as mac_create_cred() was
called from crdup() as opposed to during process creation.  For
a number of policies, this removes the requirement for special
handling when copying credential labels, and improves consistency.

Approved by:	re (scottl)
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-12-06 21:48:03 +00:00
Robert Watson
2e8c6b2654 Use UMA zone allocator for Biba and MLS labels rather than MALLOC(9).
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-11-18 04:11:52 +00:00
Robert Watson
a557af222b Introduce a MAC label reference in 'struct inpcb', which caches
the   MAC label referenced from 'struct socket' in the IPv4 and
IPv6-based protocols.  This permits MAC labels to be checked during
network delivery operations without dereferencing inp->inp_socket
to get to so->so_label, which will eventually avoid our having to
grab the socket lock during delivery at the network layer.

This change introduces 'struct inpcb' as a labeled object to the
MAC Framework, along with the normal circus of entry points:
initialization, creation from socket, destruction, as well as a
delivery access control check.

For most policies, the inpcb label will simply be a cache of the
socket label, so a new protocol switch method is introduced,
pr_sosetlabel() to notify protocols that the socket layer label
has been updated so that the cache can be updated while holding
appropriate locks.  Most protocols implement this using
pru_sosetlabel_null(), but IPv4/IPv6 protocols using inpcbs use
the the worker function in_pcbsosetlabel(), which calls into the
MAC Framework to perform a cache update.

Biba, LOMAC, and MLS implement these entry points, as do the stub
policy, and test policy.

Reviewed by:	sam, bms
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-11-18 00:39:07 +00:00
Robert Watson
6afba1a91f Don't implement mpo_destroy() for Biba, LOMAC, and MLS, as they
aren't allowed to be unloaded.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-11-17 01:04:07 +00:00
Robert Watson
b0323ea3aa Implement sockets support for __mac_get_fd() and __mac_set_fd()
system calls, and prefer these calls over getsockopt()/setsockopt()
for ABI reasons.  When addressing UNIX domain sockets, these calls
retrieve and modify the socket label, not the label of the
rendezvous vnode.

- Create mac_copy_socket_label() entry point based on
  mac_copy_pipe_label() entry point, intended to copy the socket
  label into temporary storage that doesn't require a socket lock
  to be held (currently Giant).

- Implement mac_copy_socket_label() for various policies.

- Expose socket label allocation, free, internalize, externalize
  entry points as non-static from mac_net.c.

- Use mac_socket_label_set() in __mac_set_fd().

MAC-aware applications may now use mac_get_fd(), mac_set_fd(), and
mac_get_peer() to retrieve and set various socket labels without
directly invoking the getsockopt() interface.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-11-16 23:31:45 +00:00
Robert Watson
4af32bd8a0 Remove extraneous fullpath variable, which broke lint build. This
extra argument to the devfs MAC policy entry points was accidentally
merged from the MAC branch during my earlier commit to these policies,
and is not scheduled to be merged just yet.
2003-11-12 15:09:39 +00:00
Robert Watson
eca8a663d4 Modify the MAC Framework so that instead of embedding a (struct label)
in various kernel objects to represent security data, we embed a
(struct label *) pointer, which now references labels allocated using
a UMA zone (mac_label.c).  This allows the size and shape of struct
label to be varied without changing the size and shape of these kernel
objects, which become part of the frozen ABI with 5-STABLE.  This opens
the door for boot-time selection of the number of label slots, and hence
changes to the bound on the number of simultaneous labeled policies
at boot-time instead of compile-time.  This also makes it easier to
embed label references in new objects as required for locking/caching
with fine-grained network stack locking, such as inpcb structures.

This change also moves us further in the direction of hiding the
structure of kernel objects from MAC policy modules, not to mention
dramatically reducing the number of '&' symbols appearing in both the
MAC Framework and MAC policy modules, and improving readability.

While this results in minimal performance change with MAC enabled, it
will observably shrink the size of a number of critical kernel data
structures for the !MAC case, and should have a small (but measurable)
performance benefit (i.e., struct vnode, struct socket) do to memory
conservation and reduced cost of zeroing memory.

NOTE: Users of MAC must recompile their kernel and all MAC modules as a
result of this change.  Because this is an API change, third party
MAC modules will also need to be updated to make less use of the '&'
symbol.

Suggestions from:	bmilekic
Obtained from:		TrustedBSD Project
Sponsored by:		DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
Robert Watson
54e2c147b1 Implementations of mpo_check_vnode_deleteextattr() and
mpo_check_vnode_listextattr() for Biba, MLS, and BSD Extended.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-08-21 14:34:54 +00:00
Robert Watson
130316479a Improve consistency with the Biba policy -- rename
mac_mls_subject_equal_ok() to mac_mls_subject_privileged(),
which more consistently reflects the fact that this is really
about our notion of privilege in the MLS policy.

Since we don't use suser() for privilege in MLS, remove
the suser check from the ifnet relabel ioctl, and replace it
with an MLS privilege check.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-07-31 20:00:06 +00:00
Robert Watson
f51e58036e Redesign the externalization APIs from the MAC Framework to
the MAC policy modules to improve robustness against C string
bugs and vulnerabilities.  Following these revisions, all
string construction of labels for export to userspace (or
elsewhere) is performed using the sbuf API, which prevents
the consumer from having to perform laborious and intricate
pointer and buffer checks.  This substantially simplifies
the externalization logic, both at the MAC Framework level,
and in individual policies; this becomes especially useful
when policies export more complex label data, such as with
compartments in Biba and MLS.

Bundled in here are some other minor fixes associated with
externalization: including avoiding malloc while holding the
process mutex in mac_lomac, and hence avoid a failure mode
when printing labels during a downgrade operation due to
the removal of the M_NOWAIT case.

This has been running in the MAC development tree for about
three weeks without problems.

Obtained from:	TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
2003-06-23 01:26:34 +00:00
Robert Watson
f32bb0529b Use mac_biba_label_copy() and mac_mls_label_copy() to implement the
mpo_copy_mbuf_label() entry point for Biba and MLS, respectively.
Otherwise, labels in m_tags may not be properly propagated across
some classes of mbuf operations.  This problem caused these policies
to fail-stop the system with a panic.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-06-02 17:21:38 +00:00
Robert Watson
05e830f1e7 Rewrite Biba and MLS label externalization code to use sbufs instead
of C strings internally; C strings require a lot of return value
checking that (a) takes a lot of space, and (b) is difficult to get
right.  Prior to the advent of compartment support, modeling APIs
for helper functions on snprintf worked fine; with the additional
complexity, the sbuf_printf() API makes a lot more sense.

While doing this, break out the printing of sequential compartment
lists into a helper function, mac_{biba,mls}_compartment_to_string().
This permits the main body of mac_{biba,mls}_element_to_string()
to be concerned only with identifying sequential ranges rather
than rendering.

At a less disruptive moment, we'll push the move from snprintf()-like
interface to sbuf()-like interface up into the MAC Framework layer.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-05-31 19:01:44 +00:00
Robert Watson
c2ea1fec5b Make sure all character pointers are properly initialized; this was
mismerged from the MAC tree, and didn't get picked up because warnings
are not normally fatal in per-module builds, only when they are linked
into a kernel (such as LINT).

Reported by:	des and the technicolor tinderbox
Approved by:	re (scottl)
2003-05-30 17:02:36 +00:00
Robert Watson
7792fe5719 Use strsep() in preference to manual string parsing for Biba and MLS
label internalization.  Use sensible variable names.  Include comments.
Doesn't fix any known bugs, but may fix unknown ones.

Approved by:	re (scottl)
2003-05-29 22:51:52 +00:00
Robert Watson
9a1b0237a7 Enable the MAC_ALWAYS_LABEL_MBUF flag for the Biba, LOMAC, MLS, and Test
policies.  Missed in earlier merge.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-04-15 20:51:18 +00:00
Robert Watson
78183ac2d2 Trim "trustedbsd_" from the front of the policy module "short names";
the vendor is only included in the long name currently, reducing
verbosity when modules are registered and unregistered.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-03-27 19:26:39 +00:00
Robert Watson
5e7ce4785f Modify the mac_init_ipq() MAC Framework entry point to accept an
additional flags argument to indicate blocking disposition, and
pass in M_NOWAIT from the IP reassembly code to indicate that
blocking is not OK when labeling a new IP fragment reassembly
queue.  This should eliminate some of the WITNESS warnings that
have started popping up since fine-grained IP stack locking
started going in; if memory allocation fails, the creation of
the fragment queue will be aborted.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-03-26 15:12:03 +00:00
Robert Watson
4c64787a5b Expand scope of the MLS policy to include a new entry point available
for enforcement:

  mac_mls_check_system_swapon() - Require that the subject and the
  swapfile target vnode labels dominate one another.  An additional
  check is probably needed here to require that the swapfile target
  has a label of mls/high to prevent information leakage through
  swapfiles.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-03-25 01:16:10 +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
Robert Watson
12613c76cc Place more stringent checks on process credential relabeling for the Biba
and MLS policies: as we support both an effective (single) element and
range (available) elements, require that the single be in the range if
both the single and range are defined in the update.  Remove comments
suggesting that such a check might be a good idea.

Don't introduce a similar check for network interfaces; due to different
interpretations of the single and range elements, it's not clear that
it's useful to do so.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-02-04 21:28:46 +00:00
Robert Watson
4d2ec8debb Rename the variable 'grade' to 'type' in interface parsing and
labeling for Biba.

Rename the variable 'level' to 'type' in interface parsing and
labeling for MLS.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-02-04 21:00:51 +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
Robert Watson
eba0370d90 Default policies to on: if you load them or compile them into your
kernel, you should expect them to do something, so now they do.  This
doesn't affect users who don't load or explicitly compile in the
policies.

Approved by:	re (jhb)
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-12-10 16:20:34 +00:00
Robert Watson
990b4b2dc5 Remove dm_root entry from struct devfs_mount. It's never set, and is
unused.  Replace it with a dm_mount back-pointer to the struct mount
that the devfs_mount is associated with.  Export that pointer to MAC
Framework entry points, where all current policies don't use the
pointer.  This permits the SEBSD port of SELinux's FLASK/TE to compile
out-of-the-box on 5.0-CURRENT with full file system labeling support.

Approved by:	re (murray)
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-12-09 03:44:28 +00:00
Robert Watson
63b6f478ec Garbage collect mac_create_devfs_vnode() -- it hasn't been used since
we brought in the new cache and locking model for vnode labels.  We
now rely on mac_associate_devfs_vnode().

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-12 04:20:36 +00:00
Robert Watson
ef5def596d Update MAC modules for changes in arguments for exec MAC policy
entry points to include an explicit execlabel.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-08 18:04:36 +00:00
Robert Watson
939b97cba6 Update policy modules for changes in arguments associated with support
for label access on the interpreter, not just the shell script.  No
policies currently present in the system rely on the new labels.
2002-11-05 17:52:42 +00:00
Robert Watson
b317d6f0aa Since neither the Biba policy nor the MLS policy make use of
transitioning, remove their transition entry points.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-05 16:44:29 +00:00
Robert Watson
dc858fcabe License and wording updates: NAI has authorized the removal of clause
three from their BSD-style license.  Also, s/NAI Labs/Network Associates
Laboratories/.
2002-11-04 01:53:12 +00:00
Maxime Henrion
e6faed4db0 Fix some warnings on 64 bit architectures. The vn_extattr_get()
function takes an int * parameter, not a size_t * parameter.

Arguably, it should rather take a size_t *, but that would
require changing the uio_resid field of struct uio to be a size_t
instead of an int, which I don't want to do that close to
5.0-RELEASE.

Reviewed by:	rwatson
2002-11-02 20:16:35 +00:00
Robert Watson
5c8dd34218 Move to C99 sparse structure initialization for the mac_policy_ops
structure definition, rather than using an operation vector
we translate into the structure.  Originally, we used a vector
for two reasons:

(1) We wanted to define the structure sparsely, which wasn't
    supported by the C compiler for structures.  For a policy
    with five entry points, you don't want to have to stick in
    a few hundred NULL function pointers.

(2) We thought it would improve ABI compatibility allowing modules
    to work with kernels that had a superset of the entry points
    defined in the module, even if the kernel had changed its
    entry point set.

Both of these no longer apply:

(1) C99 gives us a way to sparsely define a static structure.

(2) The ABI problems existed anyway, due to enumeration numbers,
    argument changes, and semantic mismatches.  Since the going
    rule for FreeBSD is that you really need your modules to
    pretty closely match your kernel, it's not worth the
    complexity.

This submit eliminates the operation vector, dynamic allocation
of the operation structure, copying of the vector to the
structure, and redoes the vectors in each policy to direct
structure definitions.  One enourmous benefit of this change
is that we now get decent type checking on policy entry point
implementation arguments.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-30 18:48:51 +00:00
Robert Watson
b914de36c0 While 'mode_t' seemed like a good idea for the access mode argument for
MAC access() and open() checks, the argument actually has an int type
where it becomes available.  Switch to using 'int' for the mode argument
throughout the MAC Framework and policy modules.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-30 17:56:57 +00:00
Robert Watson
c4c30e32ac Correct a typo in a previously commented include entry that was made
visible in the recent commit.
2002-10-28 19:50:06 +00:00
Robert Watson
f30a9615fd Remove all reference to 'struct oldmac', since it's no longer required
with the new VFS/EA semantics in the MAC framework.  Move the per-policy
structures out to per-policy include files, removing all policy-specific
defines and structures out of the base framework includes and
implementation, making mac_biba and mac_mls entirely self-contained.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-28 19:44:05 +00:00
Robert Watson
763bbd2f4f Slightly change the semantics of vnode labels for MAC: rather than
"refreshing" the label on the vnode before use, just get the label
right from inception.  For single-label file systems, set the label
in the generic VFS getnewvnode() code; for multi-label file systems,
leave the labeling up to the file system.  With UFS1/2, this means
reading the extended attribute during vfs_vget() as the inode is
pulled off disk, rather than hitting the extended attributes
frequently during operations later, improving performance.  This
also corrects sematics for shared vnode locks, which were not
previously present in the system.  This chances the cache
coherrency properties WRT out-of-band access to label data, but in
an acceptable form.  With UFS1, there is a small race condition
during automatic extended attribute start -- this is not present
with UFS2, and occurs because EAs aren't available at vnode
inception.  We'll introduce a work around for this shortly.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-26 14:38:24 +00:00
Robert Watson
103bcded1d Style fix: space between 'switch' and '('. 2002-10-22 19:01:49 +00:00
Robert Watson
11f0df9ed0 s/mls/biba/ in a copy+paste error for a printf. 2002-10-22 18:36:47 +00:00
Robert Watson
24e8d0d07b Adapt MAC policies for the new user API changes; teach policies how
to parse their own label elements (some cleanup to occur here in the
future to use the newly added kernel strsep()).  Policies now
entirely encapsulate their notion of label in the policy module.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-22 14:31:34 +00:00
Robert Watson
36cf29fd8d Introduce mac_biba_copy() and mac_mls_copy(), which conditionally
copy elements of one Biba or MLS label to another based on the flags
on the source label element.  Use this instead of
mac_{biba,mls}_{single,range}() to simplify the existing code, as
well as support partial label updates (we don't update if none is
requested).

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-21 20:55:39 +00:00
Robert Watson
2a1c79af92 Add compartment support to Biba and MLS policies. The logic of the
policies remains the same: subjects and objects are labeled for
integrity or sensitivity, and a dominance operator determines whether
or not subject/object accesses are permitted to limit inappropriate
information flow.  Compartments are a non-hierarchal component to
the label, so add a bitfield to the label element for each, and a
set check as part of the dominance operator.  This permits the
implementation of "need to know" elements of MLS.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-21 18:42:01 +00:00
Robert Watson
b382fe8964 More in the way of minor consistency improvements: trim 'mac_mls_'
from another variable to line this up with mac_biba.c

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-21 18:14:30 +00:00
Robert Watson
2f7f04362b Demote sockets to single-label objects rather than maintaining a
range on them, leaving process credentials as the only kernel
objects with label ranges in the Biba and MLS policies.  We
weren't using the range in any access control decisions, so this
lets us garbage collect effectively unused code.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-21 18:05:12 +00:00
Robert Watson
5f9f912a3a White space nit the crept in during merge. 2002-10-21 17:01:30 +00:00
Robert Watson
b7c2a7f406 Since the Biba and MLS access checks are identical to the open checks,
collapse the two cases more cleanly: rather than wrapping an access
check around open, simply provide the open implementation for the
access vector entry.  No functional change.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-21 16:39:12 +00:00
Robert Watson
b5f072b5e1 Cleanup of relabel authorization checks -- almost identical logic,
we just break out some of the tests better.  Minor change in that
we now better support incremental update of labels.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-21 16:35:54 +00:00