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

Additional commits post-branch will follow.

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

- For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
version of the releasing functions for mutex, rwlock and sxlock.
Failing to do so skips the lockstat_probe_func invokation for
unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
kernel compiled without lock debugging options, potentially every
consumer must be compiled including opt_kdtrace.h.
Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested. As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while. Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by: EMC / Isilon storage division
Discussed with: rstone
[0] Reported by: rstone
[1] Discussed with: philip

Rename MAC Framework-internal macros used to invoke policy entry points:

MAC_BOOLEAN -> MAC_POLICY_BOOLEAN
MAC_BOOLEAN_NOSLEEP -> MAC_POLICY_BOOLEANN_NOSLEEP
MAC_CHECK -> MAC_POLICY_CHECK
MAC_CHECK_NOSLEEP -> MAC_POLICY_CHECK_NOSLEEP
MAC_EXTERNALIZE -> MAC_POLICY_EXTERNALIZE
MAC_GRANT -> MAC_POLICY_GRANT
MAC_GRANT_NOSLEEP -> MAC_POLICY_GRANT_NOSLEEP
MAC_INTERNALIZE -> MAC_POLICY_INTERNALIZE
MAC_PERFORM -> MAC_POLICY_PERFORM_CHECK
MAC_PERFORM_NOSLEEP -> MAC_POLICY_PERFORM_NOSLEEP

This frees up those macro names for use in wrapping calls into the MAC
Framework from the remainder of the kernel.

Obtained from: TrustedBSD Project

Rework MAC Framework synchronization in a number of ways in order to
improve performance:

- Eliminate custom reference count and condition variable to monitor
threads entering the framework, as this had both significant overhead
and behaved badly in the face of contention.

- Replace reference count with two locks: an rwlock and an sx lock,
which will be read-acquired by threads entering the framework
depending on whether a give policy entry point is permitted to sleep
or not.

- Replace previous mutex locking of the reference count for exclusive
access with write acquiring of both the policy list sx and rw locks,
which occurs only when policies are attached or detached.

- Do a lockless read of the dynamic policy list head before acquiring
any locks in order to reduce overhead when no dynamic policies are
loaded; this a race we can afford to lose.

- For every policy entry point invocation, decide whether sleeping is
permitted, and if not, use a _NOSLEEP() variant of the composition
macros, which will use the rwlock instead of the sxlock. In some
cases, we decide which to use based on allocation flags passed to the
MAC Framework entry point.

As with the move to rwlocks/rmlocks in pfil, this may trigger witness
warnings, but these should (generally) be false positives as all
acquisition of the locks is for read with two very narrow exceptions
for policy load/unload, and those code blocks should never acquire
other locks.

Sponsored by: Google, Inc.
Obtained from: TrustedBSD Project
Discussed with: csjp (idea, not specific patch)

Add static DTrace probes for MAC Framework access control checks and
privilege grants so that dtrace can be more easily used to monitor
the security decisions being generated by the MAC Framework following
policy invocation.

Successful access control checks will be reported by:

mac_framework:kernel:<entrypoint>:mac_check_ok

Failed access control checks will be reported by:

mac_framework:kernel:<entrypoint>:mac_check_err

Successful privilege grants will be reported by:

mac_framework:kernel:priv_grant:mac_grant_ok

Failed privilege grants will be reported by:

mac_framework:kernel:priv_grant:mac_grant_err

In all cases, the return value (always 0 for _ok, otherwise an errno
for _err) will be reported via arg0 on the probe, and subsequent
arguments will hold entrypoint-specific data, in a style similar to
privilege tracing.

Obtained from: TrustedBSD Project
Sponsored by: Google, Inc.

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

Normalize variable naming in the MAC Framework by adopting the normal
variable name conventions for arguments passed into the framework --
for example, name network interfaces 'ifp', sockets 'so', mounts 'mp',
mbufs 'm', processes 'p', etc, wherever possible. Previously there
was significant variation in this regard.

Normalize copyright lists to ranges where sensible.

Remove MAC Framework access control check entry points made redundant with
the introduction of priv(9) and MAC Framework entry points for privilege
checking/granting. These entry points exactly aligned with privileges and
provided no additional security context:

- mac_check_sysarch_ioperm()
- mac_check_kld_unload()
- mac_check_settime()
- mac_check_system_nfsd()

Add mpo_priv_check() implementations to Biba and LOMAC policies, which,
for each privilege, determine if they can be granted to processes
considered unprivileged by those two policies. These mostly, but not
entirely, align with the set of privileges granted in jails.

Obtained from: TrustedBSD Project

Continue 7-CURRENT MAC Framework rearrangement and cleanup:

Don't perform a nested include of _label.h in mac.h, as mac.h now
describes only the user API to MAC, and _label.h defines the in-kernel
representation of MAC labels.

Remove mac.h includes from policies and MAC framework components that do
not use userspace MAC API definitions.

Add _KERNEL inclusion checks to mac_internal.h and mac_policy.h, as these
are kernel-only include files

Obtained from: TrustedBSD Project

Move src/sys/sys/mac_policy.h, the kernel interface between the MAC
Framework and security modules, to src/sys/security/mac/mac_policy.h,
completing the removal of kernel-only MAC Framework include files from
src/sys/sys. Update the MAC Framework and MAC policy modules. Delete
the old mac_policy.h.

Third party policy modules will need similar updating.

Obtained from: TrustedBSD Project

Remove mac_enforce_subsystem debugging sysctls. Enforcement on
subsystems will be a property of policy modules, which may require
access control check entry points to be invoked even when not actively
enforcing (i.e., to track information flow without providing
protection).

Obtained from: TrustedBSD Project
Suggested by: Christopher dot Vance at sparta dot com

Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges. These may
require some future tweaking.

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>

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

Correct grammar error in comment

MFC after: 3 days

add missing #include <sys/module.h>

Reimplement sysctls handling by MAC framework.
Now I believe it is done in the right way.

Removed some XXMAC cases, we now assume 'high' integrity level for all
sysctls, except those with CTLFLAG_ANYBODY flag set. No more magic.

Reviewed by: rwatson
Approved by: rwatson, scottl (mentor)
Tested with: LINT (compilation), mac_biba(4) (functionality)

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

Remove non-system bits from mac_system.c. Leave:

Enforce_kld, enforce_system access control toggles.
Access control checks for: kenv operation, kld operations,
sysarch_ioperm(), acct(), nfsd(), reboot(), settime(), swapon(),
swapoff(), sysctl().

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Forced commit to recognize repo-copy from src/sys/kern/kern_mac.c to
src/sys/security/mac/mac_{internal.h,net.c,pipe.c,process.c,system.c,
vfs.c}. kern_mac.c has rapidly become the second-largest file in
src/sys/kern, and was not well organized. In follow-up commits,
components of the MAC Framework will be broken out into different
mac_* files.

Thanks Joe!

If the struct mac copied into the kernel has a negative length, return
EINVAL rather than failing the following malloc due to the value being
too large.

Fix a mac_policy_list reference to be a mac_static_policy_list
reference: this fixes mac_syscall() for static policies when using
optimized locking.

Obtained from: TrustedBSD Project
Sponosred by: DARPA, Network Associates Laboratories

Introduce two new MAC Framework and MAC policy entry points:

mac_reflect_mbuf_icmp()
mac_reflect_mbuf_tcp()

These entry points permit MAC policies to do "update in place"
changes to the labels on ICMP and TCP mbuf headers when an ICMP or
TCP response is generated to a packet outside of the context of
an existing socket. For example, in respond to a ping or a RST
packet to a SYN on a closed port.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Add mac_check_vnode_deleteextattr() and mac_check_vnode_listextattr():
explicit access control checks to delete and list extended attributes
on a vnode, rather than implicitly combining with the setextattr and
getextattr checks. This reflects EA API changes in the kernel made
recently, including the move to explicit VOP's for both of these
operations.

Obtained from: TrustedBSD PRoject
Sponsored by: DARPA, Network Associates Laboratories

Remove about 40 lines of #ifdef/#endif by using new macros
MAC_DEBUG_COUNTER_INC() and MAC_DEBUG_COUNTER_DEC() to maintain
debugging counter values rather than #ifdef'ing the atomic
operations to MAC_DEBUG.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Attempt to simplify #ifdef logic for MAC_ALWAYS_LABEL_MBUF.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

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

Add a f_vnode field to struct file.

Several of the subtypes have an associated vnode which is used for
stuff like the f*() functions.

By giving the vnode a speparate field, a number of checks for the specific
subtype can be replaced simply with a check for f_vnode != NULL, and
we can later free f_data up to subtype specific use.

At this point in time, f_data still points to the vnode, so any code I
might have overlooked will still work.

Use __FBSDID().

Rename MAC_MAX_POLICIES to MAC_MAX_SLOTS, since the variables and
constants in question refer to the number of label slots, not the
maximum number of policies that may be loaded. This should reduce
confusion regarding an element in the MAC sysctl MIB, as well as
make it more clear what the affect of changing the compile-time
constants is.

Approved by: re (jhb)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Clean up locking for the MAC Framework:

(1) Accept that we're now going to use mutexes, so don't attempt
to avoid treating them as mutexes. This cleans up locking
accessor function names some.

(2) Rename variables to _mtx, _cv, _count, simplifying the naming.

(3) Add a new form of the _busy() primitive that conditionally
makes the list busy: if there are entries on the list, bump
the busy count. If there are no entries, don't bump the busy
count. Return a boolean indicating whether or not the busy
count was bumped.

(4) Break mac_policy_list into two lists: one with the same name
holding dynamic policies, and a new list, mac_static_policy_list,
which holds policies loaded before mac_late and without the
unload flag set. The static list may be accessed without
holding the busy count, since it can't change at run-time.

(5) In general, prefer making the list busy conditionally, meaning
we pay only one mutex lock per entry point if all modules are
on the static list, rather than two (since we don't have to
lower the busy count when we're done with the framework). For
systems running just Biba or MLS, this will halve the mutex
accesses in the network stack, and may offer a substantial
performance benefits.

(6) Lay the groundwork for a dynamic-free kernel option which
eliminates all locking associated with dynamically loaded or
unloaded policies, for pre-configured systems requiring
maximum performance but less run-time flexibility.

These changes have been running for a few weeks on MAC development
branch systems.

Approved by: re (jhb)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

- Acquire the vm_object's lock when performing vm_object_page_clean().
- Add a parameter to vm_pageout_flush() that tells vm_pageout_flush()
whether its caller has locked the vm_object. (This is a temporary
measure to bootstrap vm_object locking.)

Update NAI copyright to 2003, missed in earlier commits and merges.

mac_init_mbuf_tag() accepts malloc flags, not mbuf allocator flags, so
don't try and convert the argument flags to malloc flags, or we risk
implicitly requesting blocking and generating witness warnings.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Move MAC label storage for mbufs into m_tags from the m_pkthdr structure,
returning some additional room in the first mbuf in a chain, and
avoiding feature-specific contents in the mbuf header. To do this:

- Modify mbuf_to_label() to extract the tag, returning NULL if not
found.

- Introduce mac_init_mbuf_tag() which does most of the work
mac_init_mbuf() used to do, except on an m_tag rather than an
mbuf.

- Scale back mac_init_mbuf() to perform m_tag allocation and invoke
mac_init_mbuf_tag().

- Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since
m_tag's are now GC'd deep in the m_tag/mbuf code rather than
at a higher level when mbufs are directly free()'d.

- Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related
notions.

- Generally change all references to mbuf labels so that they use
mbuf_to_label() rather than &mbuf->m_pkthdr.label. This
required no changes in the MAC policies (yay!).

- Tweak mbuf release routines to not call mac_destroy_mbuf(),
tag destruction takes care of it for us now.

- Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() --
the existing m_tag support does all this for us. Note that
we can no longer just zero the m_tag list on the target mbuf,
rather, we have to delete the chain because m_tag's will
already be hung off freshly allocated mbuf's.

- Tweak m_tag copying routines so that if we're copying a MAC
m_tag, we don't do a binary copy, rather, we initialize the
new storage and do a deep copy of the label.

- Remove use of MAC_FLAG_INITIALIZED in a few bizarre places
having to do with mbuf header copies previously.

- When an mbuf is copied in ip_input(), we no longer need to
explicitly copy the label because it will get handled by the
m_tag code now.

- No longer any weird handling of MAC labels in if_loop.c during
header copies.

- Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test.
In mac_test, handle the label==NULL case, since it can be
dynamically loaded.

In order to improve performance with this change, introduce the notion
of "lazy MAC label allocation" -- only allocate m_tag storage for MAC
labels if we're running with a policy that uses MAC labels on mbufs.
Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS
flag in their load-time flags field during declaration. Note: this
opens up the possibility of post-boot policy modules getting back NULL
slot entries even though they have policy invariants of non-NULL slot
entries, as the policy might have been loaded after the mbuf was
allocated, leaving the mbuf without label storage. Policies that cannot
handle this case must be declared as NOTLATE, or must be modified.

- mac_labelmbufs holds the current cumulative status as to whether
any policies require mbuf labeling or not. This is updated whenever
the active policy set changes by the function mac_policy_updateflags().
The function iterates the list and checks whether any have the
flag set. Write access to this variable is protected by the policy
list; read access is currently not protected for performance reasons.
This might change if it causes problems.

- Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update
function to assert appropriate locks.

- This makes allocation in mac_init_mbuf() conditional on the flag.

Reviewed by: sam
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Abstract access to the mbuf header label behind a new function,
mbuf_to_label(). This permits the vast majority of entry point code
to be unaware that labels are stored in m->m_pkthdr.label, such that
we can experiment storage of labels elsewhere (such as in m_tags).

Reviewed by: sam
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Introduce an M_ASSERTPKTHDR() macro which performs the very common task
of asserting that an mbuf has a packet header. Use it instead of hand-
rolled versions wherever applicable.

Submitted by: Hiten Pandya <hiten@unixdaemons.com>

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

Instrument sysarch() MD privileged I/O access interfaces with a MAC
check, mac_check_sysarch_ioperm(), permitting MAC security policy
modules to control access to these interfaces. Currently, they
protect access to IOPL on i386, and setting HAE on Alpha.
Additional checks might be required on other platforms to prevent
bypass of kernel security protections by unauthorized processes.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Provide a mac_check_system_swapoff() entry point, which permits MAC
modules to authorize disabling of swap against a particular vnode.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Replace calls to WITNESS_SLEEP() and witness_list() with equivalent calls
to WITNESS_WARN().

Back out M_* changes, per decision of the TRB.

Approved by: trb

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

Bow to the whining masses and change a union back into void *. Retain
removal of unnecessary casts and throw in some minor cleanups to see if
anyone complains, just for the hell of it.

Change struct file f_data to un_data, a union of the correct struct
pointer types, and remove a huge number of casts from code using it.

Change struct xfile xf_data to xun_data (ABI is still compatible).

If we need to add a #define for f_data and xf_data we can, but I don't
think it will be necessary. There are no operational changes in this
commit.

SCARGS removal take II.

Backout removal SCARGS, the code freeze is only "selectively" over.

Remove SCARGS.

Reviewed by: md5

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

Un-staticize mac_cred_mmapped_drop_perms() so that it may be used
by policy modules making use of downgrades in the MAC AST event. This
is required by the mac_lomac port of LOMAC to the MAC Framework.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Introduce p_label, extensible security label storage for the MAC framework
in struct proc. While the process label is actually stored in the
struct ucred pointed to by p_ucred, there is a need for transient
storage that may be used when asynchronous (deferred) updates need to
be performed on the "real" label for locking reasons. Unlike other
label storage, this label has no locking semantics, relying on policies
to provide their own protection for the label contents, meaning that
a policy leaf mutex may be used, avoiding lock order issues. This
permits policies that act based on historical process behavior (such
as audit policies, the MAC Framework port of LOMAC, etc) can update
process properties even when many existing locks are held without
violating the lock order. No currently committed policies implement use
of this label storage.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Merge kld access control checks from the MAC tree: these access control
checks permit policy modules to augment the system policy for permitting
kld operations. This permits policies to limit access to kld operations
based on credential (and other) properties, as well as to perform checks
on the kld being loaded (integrity, etc).

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Introduce a condition variable to avoid returning EBUSY when
the MAC policy list is busy during a load or unload attempt.
We assert no locks held during the cv wait, meaning we should
be fairly deadlock-safe. Because of the cv model and busy
count, it's possible for a cv waiter waiting for exclusive
access to the policy list to be starved by active and
long-lived access control/labeling events. For now, we
accept that as a necessary tradeoff.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

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

Garbage collect definition of M_MACOPVEC -- we no longer perform a
dynamic mapping of an operation vector into an operation structure,
rather, we rely on C99 sparse structure initialization.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Add an explicit execlabel argument to exec-related MAC policy entry
points, rather than relying on policies to grub around in the
image activator instance structure.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Bring in two sets of changes:

(1) Permit userland applications to request a change of label atomic
with an execve() via mac_execve(). This is required for the
SEBSD port of SELinux/FLASK. Attempts to invoke this without
MAC compiled in result in ENOSYS, as with all other MAC system
calls. Complexity, if desired, is present in policy modules,
rather than the framework.

(2) Permit policies to have access to both the label of the vnode
being executed as well as the interpreter if it's a shell
script or related UNIX nonsense. Because we can't hold both
vnode locks at the same time, cache the interpreter label.
SEBSD relies on this because it supports secure transitioning
via shell script executables. Other policies might want to
take both labels into account during an integrity or
confidentiality decision at execve()-time.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Assert that appropriate vnodes are locked in mac_execve_will_transition().
Allow transitioning to be twiddled off using the process and fs enforcement
flags, although at some point this should probably be its own flag.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Permit MAC policies to instrument the access control decisions for
system accounting configuration and for nfsd server thread attach.
Policies might use this to protect the integrity or confidentiality
of accounting data, limit the ability to turn on or off accounting,
as well as to prevent inappropriately labeled threads from becoming nfs
server threads.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Remove mac_cache_fslabel_in_vnode sysctl -- with the new VFS/MAC
construction, labels are always cached.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

License clarification and wording changes: NAI has approved removal of
clause three, and NAI Labs now goes by the name Network Associates
Laboratories.

Introduce mac_check_system_settime(), a MAC check allowing policies to
augment the system policy for changing the system time.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Add MAC checks for various kenv() operations: dump, get, set, unset,
permitting MAC policies to limit access to the kernel environment.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

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

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

An inappropriate ASSERT slipped in during the recent merge of the
reboot checking; remove.

Centrally manage enforcement of {reboot,swapon,sysctl} using the
mac_enforce_system toggle, rather than several separate toggles.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Implement mac_check_system_sysctl(), a MAC Framework entry point to
permit MAC policies to augment the security protections on sysctl()
operations. This is not really a wonderful entry point, as we
only have access to the MIB of the target sysctl entry, rather than
the more useful entry name, but this is sufficient for policies
like Biba that wish to use their notions of privilege or integrity
to prevent inappropriate sysctl modification. Affects MAC kernels
only. Since SYSCTL_LOCK isn't in sysctl.h, just kern_sysctl.c,
we can't assert the SYSCTL subsystem lockin the MAC Framework.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Hook up mac_check_system_reboot(), a MAC Framework entry point that
permits MAC modules to augment system security decisions regarding
the reboot() system call, if MAC is compiled into the kernel.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Merge from MAC tree: rename mac_check_vnode_swapon() to
mac_check_system_swapon(), to reflect the fact that the primary
object of this change is the running kernel as a whole, rather
than just the vnode. We'll drop additional checks of this
class into the same check namespace, including reboot(),
sysctl(), et al.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

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

Comment describing the semantics of mac_late.
Trim trailing whitespace.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Introduce MAC_CHECK_VNODE_SWAPON, which permits MAC policies to
perform authorization checks during swapon() events; policies
might choose to enforce protections based on the credential
requesting the swap configuration, the target of the swap operation,
or other factors such as internal policy state.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Missed in previous merge: export sizeof(struct oldmac) rather than
sizeof(struct mac).

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Support the new MAC user API in kernel: modify existing system calls
to use a modified notion of 'struct mac', and flesh out the new variation
system calls (almost identical to existing ones except that they permit
a pid to be specified for process label retrieval, and don't follow
symlinks). This generalizes the label API so that the framework is
now almost entirely policy-agnostic.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Use if_printf(ifp, "blah") instead of
printf("%s%d: blah", ifp->if_name, ifp->if_xname).

If MAC_MAX_POLICIES isn't defined, don't try to define it, just let the
compile fail. MAC_MAX_POLICIES should always be defined, or we have
bigger problems at hand.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Make sure to clear the 'registered' flag for MAC policies when they
unregister. Under some obscure (perhaps demented) circumstances,
this can result in a panic if a policy is unregistered, and then someone
foolishly unregisters it again.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Integrate mac_check_socket_send() and mac_check_socket_receive()
checks from the MAC tree: allow policies to perform access control
for the ability of a process to send and receive data via a socket.
At some point, we might also pass in additional address information
if an explicit address is requested on send.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Sync from MAC tree: break out the single mmap entry point into
seperate entry points for each occasion:

mac_check_vnode_mmap() Check at initial mapping
mac_check_vnode_mprotect() Check at mapping protection change
mac_check_vnode_mmap_downgrade() Determine if a mapping downgrade
should take place following
subject relabel.

Implement mmap() and mprotect() entry points for labeled vnode
policies. These entry points are currently not hooked up to the
VM system in the base tree. These changes improve the consistency
of the access control interface and offer more flexibility regarding
limiting access to vnode mmaping.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Modify label allocation semantics for sockets: pass in soalloc's malloc
flags so that we can call malloc with M_NOWAIT if necessary, avoiding
potential sleeps while holding mutexes in the TCP syncache code.
Similar to the existing support for mbuf label allocation: if we can't
allocate all the necessary label store in each policy, we back out
the label allocation and fail the socket creation. Sync from MAC tree.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Integrate a devfs/MAC fix from the MAC tree: avoid a race condition during
devfs VOP symlink creation by introducing a new entry point to determine
the label of the devfs_dirent prior to allocation of a vnode for the
symlink.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Merge support for mac_check_vnode_link(), a MAC framework/policy entry
point that instruments the creation of hard links. Policy implementations
to follow.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

While the MAC API has supported the ability to handle M_NOWAIT passed
to mbuf label initialization, that functionality was never merged to
the main tree. Go ahead and merge that functionality now. Note that
this requires policy modules to accept the case where the label
element may be destroyed even if init has not succeeded on it (in
the event that policy failed the init). This will shortly also
apply to sockets.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Rearrange object and label init/destroy functions to match the
order used in mac_policy.h and elsewhere. Sort order is basically
"by operation category", then "alphabetically by object". Sync to
MAC tree.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Sync to MAC tree: use 'flag' instead of 'how' for mac_init_mbuf();
remove a slightly less than useful comment.

Another big diff, little functional change: move label internalization,
externalization, and cred label life cycle events to entirely above
devfs and vnode events. Sync from MAC tree.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Move all object label init/destroy routines to the head of the
entry points to better match the entry point ordering in mac_policy.h.
Big diff, no functional change; merge from the MAC tree.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Synch from TrustedBSD MAC tree:

- If a policy isn't registered when a policy module unloads, silently
succeed.

- Hold the policy list lock across more of the validity tests to avoid
races.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Cosmetic line wrap synchronization.

Push the debugging obect label counters into security.mac.debug.counters
rather than directly under security.mac.debug.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Begin another merge from the TrustedBSD MAC branch:

- Change mpo_init_foo(obj, label) and mpo_destroy_foo(obj, label) policy
entry points to mpo_init_foo_label(label) and
mpo_destroy_foo_label(label). This will permit the use of the same
entry points for holding temporary type-specific label during
internalization and externalization, as well as for caching purposes.
- Because of this, break out mpo_{init,destroy}_socket() and
mpo_{init,destroy}_mount() into seperate entry points for socket
main/peer labels and mount main/fs labels.
- Since the prototype for label initialization is the same across almost
all entry points, implement these entry points using common
implementations for Biba, MLS, and Test, reducing the number of
almost identical looking functions.

This simplifies policy implementation, as well as preparing us for the
merge of the new flexible userland API for managing labels on objects.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Add a new MAC entry point, mac_thread_userret(td), which permits policy
modules to perform MAC-related events when a thread returns to user
space. This is required for policies that have floating process labels,
as it's not always possible to acquire the process lock at arbitrary
points in the stack during system call processing; process labels might
represent traditional authentication data, process history information,
or other data.

LOMAC will use this entry point to perform the process label update
prior to the thread returning to userspace, when plugged into the MAC
framework.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Remember to include "opt_devfs.h" so we get any relevant changes
to NDEVFSINO before we include devfs.h.

Spotted by: FlexeLint

Improve locking of pipe mutexes in the context of MAC:

(1) Where previously the pipe mutex was selectively grabbed during
pipe_ioctl(), now always grab it and then release if if not
needed. This protects the call to mac_check_pipe_ioctl() to
make sure the label remains consistent. (Note: it looks
like sigio locking may be incorrect for fgetown() since we
call it not-by-reference and sigio locking assumes call by
reference).

(2) In pipe_stat(), lock the pipe if MAC is compiled in so that
the call to mac_check_pipe_stat() gets a locked pipe to
protect label consistency. We still release the lock before
returning actual stat() data, risking inconsistency, but
apparently our pipe locking model accepts that risk.

(3) In various pipe MAC authorization checks, assert that the pipe
lock is held.

(4) Grab the lock when performing a pipe relabel operation, and
assert it a little deeper in the stack.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Push 'security.mac.debug_label_fallback' behind options MAC_DEBUG.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Add tunables for the existing sysctl twiddles for pipe and vm
enforcement so they can be disabled prior to kernel start.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Remove un-needed stack variable 'ops'.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Add a toggle to disable VM enforcement.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

At the cost of seeming a little gauche, make use of more traditional
alphabetization for mac_enforce_pipe sysctl.

Obtained from: TrustedBSD Project
Sponsored by: DAPRA, NAI Labs

Remove all use of vnode->v_tag, replacing with appropriate substitutes.
v_tag is now const char * and should only be used for debugging.

Additionally:
1. All users of VT_NTS now check vfsconf->vf_type VFCF_NETWORK
2. The user of VT_PROCFS now checks for the new flag VV_PROCDEP, which
is propagated by pseudofs to all child vnodes if the fs sets PFS_PROCDEP.

Suggested by: phk
Reviewed by: bde, rwatson (earlier version)

Add security.mac.mmap_revocation, a flag indicating whether we
should revoke access to memory maps on a process label change.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Minor code sync to MAC tree: push Giant locking up from
mac_cred_mmapped_drop_perms() to the caller.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Include <sys/malloc.h> instead of depending on namespace pollution 2
layers deep in <sys/proc.h> or <sys/vnode.h>.

Removed unused includes.

Fixed some printf format errors (1 fatal on i386's; 1 fatal on alphas;
1 not fatal on any supported machine).

Close a race in process label changing opened due to dropping the
proc locking when revoking access to mmaps. Instead, perform this
later once we've changed the process label (hold onto a reference
to the new cred so that we don't lose it when we release the
process lock if another thread changes the credential).

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Pass active_cred and file_cred into the MAC framework explicitly
for mac_check_vnode_{poll,read,stat,write}(). Pass in fp->f_cred
when calling these checks with a struct file available. Otherwise,
pass NOCRED. All currently MAC policies use active_cred, but
could now offer the cached credential semantic used for the base
system security model.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Provide an implementation of mac_syscall() so that security modules
can offer new services without reserving system call numbers, or
augmented versions of existing services. User code requests a
target policy by name, and specifies the policy-specific API plus
target. This is required in particular for our port of SELinux/FLASK
to the MAC framework since it offers additional security services.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Break out mac_check_pipe_op() into component check entry points:
mac_check_pipe_poll(), mac_check_pipe_read(), mac_check_pipe_stat(),
and mac_check_pipe_write(). This is improves consistency with other
access control entry points and permits security modules to only
control the object methods that they are interested in, avoiding
switch statements.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Break out mac_check_vnode_op() into three seperate checks:
mac_check_vnode_poll(), mac_check_vnode_read(), mac_check_vnode_write().
This improves the consistency with other existing vnode checks, and
allows policies to avoid implementing switch statements to determine
what operations they do and do not want to authorize.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Assert process locks in proces-related access control checks.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Add a missing vnode assertion for the exec() check.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Wrap maintenance of varios nmac{objectname} counters in MAC_DEBUG so we
can avoid the cost of a large number of atomic operations if we're not
interested in the object count statistics.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Rename mac_check_socket_receive() to mac_check_socket_deliver() so that
we can use the names _receive() and _send() for the receive() and send()
checks. Rename related constants, policy implementations, etc.

PR:
Submitted by:
Reviewed by:
Approved by:
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
MFC after:

Sync to trustedbsd_mac tree: default to sigsegv rather than copy-on-write
during a label change resulting in an mmap removal. This is "fail stop"
behavior, which is preferred, although it offers slightly less
transparency.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Declare a module service "kernel_mac_support" when MAC support is
enabled and the kernel provides the MAC registration and entry point
service. Declare a dependency on that module service for any
MAC module registered using mac_policy.h. For now, hard code the
version as 1, but once we've come up with a versioning policy, we'll
move to a #define of some sort. In the mean time, this will prevent
loading a MAC module when 'options MAC' isn't present, which (due to
a bug in the kernel linker) can result if the MAC module is preloaded
via loader.conf.

This particular evil recommended by: peter
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI LAbs

- Replace v_flag with v_iflag and v_vflag
- v_vflag is protected by the vnode lock and is used when synchronization
with VOP calls is needed.
- v_iflag is protected by interlock and is used for dealing with vnode
management issues. These flags include X/O LOCK, FREE, DOOMED, etc.
- All accesses to v_iflag and v_vflag have either been locked or marked with
mp_fixme's.
- Many ASSERT_VOP_LOCKED calls have been added where the locking was not
clear.
- Many functions in vfs_subr.c were restructured to provide for stronger
locking.

Idea stolen from: BSD/OS

Include file cleanup; mac.h and malloc.h at one point had ordering
relationship requirements, and no longer do.

Reminded by: bde

Begin committing support for Mandatory Access Control and extensible
kernel access control. The MAC framework permits loadable kernel
modules to link to the kernel at compile-time, boot-time, or run-time,
and augment the system security policy. This commit includes the
initial kernel implementation, although the interface with the userland
components of the oeprating system is still under work, and not all
kernel subsystems are supported. Later in this commit sequence,
documentation of which kernel subsystems will not work correctly with
a kernel compiled with MAC support will be added.

kern_mac.c contains the body of the MAC framework. Kernel and
user APIs defined in mac.h are implemented here, providing a front end
to loaded security modules. This code implements a module registration
service, state (label) management, security configuration and policy
composition.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Stubs for the TrustedBSD MAC system calls to permit TrustedBSD MAC
userland code to operate on kernel's from the main tree. Not much
in this file yet.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs