vnode and a mode and checks if a given access mode is permitted.
This centralises the mac_bsdextended_enabled check and the GETATTR
calls and makes the implementation of the mac policy methods simple.
This should make it easier for us to match vnodes on more complex
attributes than just uid and gid in the future, but for now there
should be no functional change.
Approved/Reviewed by: rwatson, trhodes
MFC after: 1 month
- Introduce a global mutex, mac_bsdextended_mtx, to protect the rule
array and hold this mutex over use and modification of the rule array
and rules.
- Re-order and clean up sysctl_rule so that copyin/copyout/update happen
in the right order (suggested by: jhb done by rwatson).
right bits rather than piggy-backing on the V* rights defined in
vnode.h. The mac_bsdextended bits are given the same values as the V*
bits to make the new kernel module binary compatible with the old
version of libugidfw that uses V* bits. This avoids leaking kernel
API/ABI to user management tools, and in particular should remove the
need for libugidfw to include vnode.h.
Requested by: phk
rule only in place of all rules match. This is similar to how ipfw(8) works.
Provide a sysctl, mac_bsdextended_firstmatch_enabled, to enable this
feature.
Reviewed by: re (jhb)
Aprroved by: re (jhb)
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
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
include a new entry point available for enforcement:
mac_bsdextended_check_system_swapon() - Apply extended access
control checks to the file target of swap.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
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
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
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
kernel access control.
Provide implementations of some sample operating system security
policy extensions. These are not yet hooked up to the build as
other infrastructure is still being committed. Most of these
work fairly well and are in daily use in our development and (limited)
production environments. Some are not yet in their final form,
and a number of the labeled policies waste a lot of kernel memory
and will be fixed over the next month or so to be more conservative.
They do give good examples of the flexibility of the MAC framework
for implementing a variety of security policies.
mac_biba: Implementation of fixed-label Biba integrity policy,
similar to those found in a number of commercial
trusted operating systems. All subjects and objects
are assigned integrity levels, and information flow
is controlled based on a read-up, write-down
policy. Currently, purely hierarchal.
mac_bsdextended: Implementation of a "file system firewall",
which allows the administrator to specify a series
of rules limiting access by users and groups to
objects owned by other users and groups. This
policy is unlabeled, relying on existing system
security labeling (file permissions/ownership,
process credentials).
mac_ifoff: Secure interface silencing. Special-purpose module
to limit inappropriate out-going network traffic
for silent monitoring scenarios. Prevents the
various network stacks from generating any output
despite an interface being live for reception.
mac_mls: Implementation of fixed-label Multi-Level Security
confidentiality policy, similar to those found in
a number of commercial trusted operating systems.
All subjects and objects are assigned confidentiality
levels, and information flow is controlled based on
a write-up, read-down policy. Currently, purely
hiearchal, although non-hierarchal support is in the
works.
mac_none: Policy module implementing all MAC policy entry
points with empty stubs. A good place to start if
you want all the prototypes types in for you, and
don't mind a bit of pruning. Can be loaded, but
has no access control impact. Useful also for
performance measurements.
mac_seeotheruids: Policy module implementing a security service
similar to security.bsd.seeotheruids, only a slightly
more detailed policy involving exceptions for members
of specific groups, etc. This policy is unlabeled,
relying on existing system security labeling
(process credentials).
mac_test: Policy module implementing basic sanity tests for
label handling. Attempts to ensure that labels are
not freed multiple times, etc, etc.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
