Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

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)

Improve the consistency of MAC Framework and MAC policy entry point
naming by renaming certain "proc" entry points to "cred" entry points,
reflecting their manipulation of credentials. For some entry points,
the process was passed into the framework but not into policies; in
these cases, stop passing in the process since we don't need it.

mac_proc_check_setaudit -> mac_cred_check_setaudit
mac_proc_check_setaudit_addr -> mac_cred_check_setaudit_addr
mac_proc_check_setauid -> mac_cred_check_setauid
mac_proc_check_setegid -> mac_cred_check_setegid
mac_proc_check_seteuid -> mac_cred_check_seteuid
mac_proc_check_setgid -> mac_cred_check_setgid
mac_proc_check_setgroups -> mac_cred_ceck_setgroups
mac_proc_check_setregid -> mac_cred_check_setregid
mac_proc_check_setresgid -> mac_cred_check_setresgid
mac_proc_check_setresuid -> mac_cred_check_setresuid
mac_proc_check_setreuid -> mac_cred_check_setreuid
mac_proc_check_setuid -> mac_cred_check_setuid

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

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.

Use __FBSDID() for $FreeBSD$ version strings in .c files.

Obtained from: TrustedBSD Project
MFC after: 3 days

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

Add a new MAC framework and policy entry point,
mpo_check_proc_setaudit_addr to be used when controlling use of
setaudit_addr(), rather than mpo_check_proc_setaudit(), which takes a
different argument type.

Reviewed by: csjp
Approved by: re (kensmith)

Allow MAC policy modules to control access to audit configuration system
calls. Add MAC Framework entry points and MAC policy entry points for
audit(), auditctl(), auditon(), setaudit(), aud setauid().

MAC Framework entry points are only added for audit system calls where
additional argument context may be useful for policy decision-making; other
audit system calls without arguments may be controlled via the priv(9)
entry points.

Update various policy modules to implement audit-related checks, and in
some cases, other missing system-related checks.

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