MAC policies to perform object life cycle operations and access
control checks.
Submitted by: Dandekar Hrishikesh <rishi_dandekar at sbcglobal dot net>
Obtained from: TrustedBSD Project
Sponsored by: DARPA, SPAWAR, McAfee Research
objects and operations:
- System V IPC message, message queue, semaphore, and shared memory
segment init, destroy, cleanup, create operations.
- System V IPC message, message queue, seamphore, and shared memory
segment access control entry points, including rights to attach,
destroy, and manipulate these IPC objects.
Submitted by: Dandekar Hrishikesh <rishi_dandekar at sbcglobal dot net>
Obtained from: TrustedBSD Project
Sponsored by: DARPA, SPAWAR, McAfee Research
changes associated with adding System V IPC support. This will prevent
old modules from being used with the new kernel, and new modules from
being used with the old kernel.
for modules linked into the kernel or loaded very early, panics will
result otherwise, as the CV code it calls will panic due to its use
of a mutex before it is initialized.
as well as document the properties of the mac_policy_conf structure.
Warn about the ABI risks in changing the structure without careful
consideration.
Obtained from: TrustedBSD Project
Sponsored by: SPAWAR
so that they know whether the allocation is supposed to be able to sleep
or not.
* Allow uma_zone constructors and initialation functions to return either
success or error. Almost all of the ones in the tree currently return
success unconditionally, but mbuf is a notable exception: the packet
zone constructor wants to be able to fail if it cannot suballocate an
mbuf cluster, and the mbuf allocators want to be able to fail in general
in a MAC kernel if the MAC mbuf initializer fails. This fixes the
panics people are seeing when they run out of memory for mbuf clusters.
* Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing
the default.
Both bmilekic and jeff have reviewed the changes made to make failable
zone allocations work.
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
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
SOCK_LOCK(so):
- Hold socket lock over calls to MAC entry points reading or
manipulating socket labels.
- Assert socket lock in MAC entry point implementations.
- When externalizing the socket label, first make a thread-local
copy while holding the socket lock, then release the socket lock
to externalize to userspace.
lookup for the label tag fails, return NULL rather than something close
to NULL. This scenario occurs if mbuf header labeling is optional and
a policy requiring labeling is loaded, resulting in some mbufs having
labels and others not. Previously, 0x14 would be returned because the
NULL from m_tag_find() was not treated specially.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
synchronization protecting against dynamic load and unload of MAC
policies, and instead simply blocks load and unload. In a static
configuration, this allows you to avoid the synchronization costs
associated with introducing dynamicism.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
Assert the BPF descriptor lock in the MAC calls referencing live
BPF descriptors.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
are employed in entry points later in the same include file.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Air Force Research Laboratory, McAfee Research
struct vattr in mac_policy.h. This permits policies not
implementing entry points using these types to compile without
including include files with these types.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Air Force Research Laboratory
to a new mac_inet.c. This code is now conditionally compiled based
on inet support being compiled into the kernel.
Move socket related MAC Framework entry points from mac_net.c to a new
mac_socket.c.
To do this, some additional _enforce MIB variables are now non-static.
In addition, mbuf_to_label() is now mac_mbuf_to_label() and non-static.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
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)
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
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
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
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
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
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
SO_PEERLABEL. This provides an interface to query the label of a
socket peer without embedding implementation details of mac_t in
the application. Previously, sizeof(*mac_t) had to be specified
by an application when performing getsockopt().
Document mac_get_peer(3), and expand documentation of the other
mac_get(3) functions. Note that it's possible to get EINVAL back
from mac_get_fd(3) when pointing it at an inappropriate object.
NOTE: mac_get_fd() and mac_set_fd() support for sockets will
follow shortly, so the documentation is slightly ahead of the
code.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
mac_setsockopt_label() into mac_socket_label_set(); make it non-static
so that it can be invoked from kern_mac.c for mac_set_fd().
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
This fixes a dependency of mac_label.c on namespace pollution in
<vm/uma.h>.
Similarly for SYSCTL_DECL() although I had no problems with it. This
probably makes some includes of <sys/sysctl.h> bogus.
Giant and is also MPSAFE.
Push Giant further down into __mac_get_fd() and __mac_set_fd(),
grabbing it only for constrained regions dealing with VFS, and
dropping it entirely for operations related to labeling of pipes.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
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
successfully initialized in the label as a socket peer label, not a
socket label. For current policy modules, this didn't make a
difference, but if a policy module had label data in the peer label
that was to be GC'd in a different way than the normal socket label,
it might have been a problem.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
type, rather than "object_label" as the first argument. This reduces
complexity a little for the consumer, and also makes it easier for
use to rename the underlying entry points in struct mac_policy_obj.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
Include src/sys/security/mac/mac_internal.h in kern_mac.c.
Remove redundant defines from the include: SYSCTL_DECL(), debug macros,
composition macros.
Unstaticize various bits now exposed to the remainder of the kernel:
mac_init_label(), mac_destroy_label().
Remove all the functions now implemented in mac_process/mac_vfs/mac_net/
mac_pipe. Also remove debug counters, sysctls exporting debug
counters, enforcement flags, sysctls exporting enforcement flags.
Leave module declaration, sysctl nodes, mactemp malloc type, system
calls.
This should conclude MAC/LINT/NOTES breakage from the break-out process,
but I'm running builds now to make sure I caught everything.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
Unstaticize mac_late.
Remove ea_warn_once, now in mac_vfs.c.
Unstaticisize mac_policy_list, mac_static_policy_list, use
struct mac_policy_list_head instead of LIST_HEAD() directly.
Unstaticize and un-inline MAC policy locking functions so they can
be referenced from mac_*.c.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
Extended attribute transaction warning flag if transactions aren't
supported on the EA implementation being used.
Debug fallback flag to permit a less conservative fallback if reading
an on-disk label fails.
Enforce_fs toggle to enforce file systme access control.
Debugging counters for file system objects: mounts, vnodes, devfs_dirents.
Object initialization, destruction, copying, internalization,
externalization, relabeling for file system objects.
Life cycle operations for devfs entries.
Generic extended attribute label implementation for use by UFS, UFS2 in
multilabel mode.
Generic single-level label implementation for use by all file systems
when in singlelabel mode.
Exec-time transition based on file label entry points.
Vnode operation access control checks (many).
Mount operation access control checks (few).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
Pipe enforcement flag.
Pipe object debugging counters.
MALLOC type for MAC label storage.
Pipe MAC label management routines, externalize/internalization/change
routines.
Pipe MAC access control checks.
Un-staticize functions called from mac_set_fd() when operating on a
pipe. Abstraction improvements in this space seem likely.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
