doc/en_US.ISO8859-1/books/developers-handbook/mac/chapter.sgml
Hideyuki KURASHINA e43017f9ba Add missing end-tags.
Submitted by:	Martin Karlsson <mk-freebsd@bredband.net>
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<chapter id="mac">
<chapterinfo>
<authorgroup>
<author>
<firstname>Chris</firstname>
<surname>Costello</surname>
<affiliation>
<orgname>TrustedBSD Project</orgname>
<address><email>chris@FreeBSD.org</email></address>
</affiliation>
</author>
<author>
<firstname>Robert</firstname>
<surname>Watson</surname>
<affiliation>
<orgname>TrustedBSD Project</orgname>
<address><email>rwatson@FreeBSD.org</email></address>
</affiliation>
</author>
</authorgroup>
</chapterinfo>
<title>The TrustedBSD MAC Framework</title>
<sect1 id="mac-copyright">
<title>MAC Documentation Copyright</title>
<para>This documentation was developed for the FreeBSD Project by
Chris Costello at Safeport Network Services and Network
Associates Laboratories, the Security Research Division of
Network Associates, Inc. under DARPA/SPAWAR contract
N66001-01-C-8035 (<quote>CBOSS</quote>), as part of the DARPA
CHATS research program.</para>
<para>Redistribution and use in source (SGML DocBook) and
'compiled' forms (SGML, HTML, PDF, PostScript, RTF and so forth)
with or without modification, are permitted provided that the
following conditions are met:</para>
<orderedlist>
<listitem>
<para>Redistributions of source code (SGML DocBook) must
retain the above copyright notice, this list of conditions
and the following disclaimer as the first lines of this file
unmodified.</para>
</listitem>
<listitem>
<para>Redistributions in compiled form (transformed to other
DTDs, converted to PDF, PostScript, RTF and other formats)
must reproduce the above copyright notice, this list of
conditions and the following disclaimer in the documentation
and/or other materials provided with the
distribution.</para>
</listitem>
</orderedlist>
<important>
<para>THIS DOCUMENTATION IS PROVIDED BY THE NETWORKS ASSOCIATES
TECHNOLOGY, INC "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL NETWORKS ASSOCIATES TECHNOLOGY,
INC BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION, EVEN
IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.</para>
</important>
</sect1>
<sect1 id="mac-synopsis">
<title>Synopsis</title>
<para>FreeBSD includes experimental support for several
mandatory access control policies, as well as a framework
for kernel security extensibility, the TrustedBSD MAC
Framework. The MAC Framework provides a pluggable access
control framework, permitting new security policies to
be easily linked into the kernel, loaded at boot, or loaded
dynamically at run-time. The framework provides a variety
of features to make it easier to implement new policies,
including the ability to easily tag security labels (such as
confidentiality information) onto system objects.</para>
<para>This chapter introduces the MAC policy framework and
provides documentation for a sample MAC policy module.</para>
</sect1>
<sect1 id="mac-introduction">
<title>Introduction</title>
<para>The TrustedBSD MAC framework provides a mechanism to allow
the compile-time or run-time extension of the kernel access
control model. New system policies may be implemented as
kernel modules and linked to the kernel; if multiple policy
modules are present, their results will be composed. The
MAC Framework provides a variety of access control infrastructure
services to assist policy writers, including support for
transient and persistent policy-agnostic object security
labels. This support is currently considered experimental.</para>
</sect1>
<sect1>
<title>Policy Background</title>
<para>Mandatory Access Control (MAC), refers to a set of
access control policies that are mandatorily enforced on
users by the operating system. MAC policies may be contrasted
with Discretionary Access Control (DAC) protections, by which
non-administrative users may (at their discretion) protect
objects. In traditional UNIX systems, DAC protections include
file permissions and access control lists; MAC protections include
process controls preventing inter-user debugging and firewalls.
A variety of MAC policies have been formulated by operating system
designers and security researches, including the Multi-Level
Security (MLS) confidentiality policy, the Biba integrity policy,
Role-Based Access Control (RBAC), and Type Enforcement (TE). Each
model bases decisions on a variety of factors, including user
identity, role, and security clearance, as well as security labels
on objects representing concepts such as data sensitivity and
integrity.</para>
<para>The TrustedBSD MAC Framework is capable of supporting policy
modules that implement all of these policies, as well as a broad
class of system hardening policies. In addition, despite the
name, the MAC Framework can also be used to implement purely
discretionary policies, as policy modules are given substantial
flexibility in how they authorize protections.</para>
</sect1>
<sect1 id="mac-framework-kernel-arch">
<title>MAC Framework Kernel Architecture</title>
<para>The TrustedBSD MAC Framework permits kernel modules to
extend the operating system security policy, as well as
providing infrastructure functionality required by many
access control modules. If multiple policies are
simultaneously loaded, the MAC Framework will usefully (for
some definition of useful) compose the results of the
policies.</para>
<sect2 id="mac-framework-kernel-arch-elements">
<title>Kernel Elements</title>
<para>The MAC Framework contains a number of kernel elements:</para>
<itemizedlist>
<listitem><para>Framework management interfaces</para></listitem>
<listitem><para>Concurrency and synchronization
primitives.</para></listitem>
<listitem><para>Policy registration</para></listitem>
<listitem><para>Extensible security label for kernel
objects</para></listitem>
<listitem><para>Policy entry point composition
operators</para></listitem>
<listitem><para>Label management primitives</para></listitem>
<listitem><para>Entry point API invoked by kernel
services</para></listitem>
<listitem><para>Entry point API to policy modules</para></listitem>
<listitem><para>Entry points implementations (policy life cycle,
object life cycle/label management, access control
checks).</para></listitem>
<listitem><para>Policy-agnostic label-management system
calls</para></listitem>
<listitem><para><function>mac_syscall()</function> multiplex
system call</para></listitem>
<listitem><para>Various security policies implemented as MAC
policy modules</para></listitem>
</itemizedlist>
</sect2>
<sect2 id="mac-framework-kernel-arch-management">
<title>Management Interfaces</title>
<para>The TrustedBSD MAC Framework may be directly managed using
sysctls, loader tunables, and system calls.</para>
<para>In most cases, sysctls and loader tunables modify the same
parameters, and control behavior such as enforcement of
protections relating to various kernel subsystems. In addition,
if MAC debugging support is compiled into the kernel, a variety
of counters will be maintained tracking label allocation. In
most cases, it is advised that per-subsystem enforcement
controls not be used to control policy behavior in production
environments, as they broadly impact the operation of all
active policies. Instead, per-policy controls should be
preferred to ensure proper policy operation.</para>
<para>Loading and unloading of policy modules is performed
using the system module management system calls and other
system interfaces, including loader variables.</para>
</sect2>
<sect2 id="mac-framework-kernel-arch-synchronization">
<title>Concurrency and Synchronization</title>
<para>As the set of active policies may change at run-time,
and the invocation of entry points is non-atomic,
synchronization is required to prevent unloading or
loading of new policies while an entry point invocation
is progress, freezing the list of policies for the
duration. This is accomplished by means of a Framework
busy count. Whenever an entry point is entered, the
busy count is incremented; whenever it is exited, the
busy count is decremented. While the busy count is
elevated, policy list changes are not permitted, and
threads attempting to modify the policy list will sleep
until the list is not busy. The busy count is protected
by a mutex, and a condition variable is used to wake up
sleepers waiting on policy list modifications.</para>
<para>Various optimizations are used to reduce the overhead
of the busy count, including avoiding the full cost of
incrementing and decrementing if the list is empty or
contains only static entries (policies that are loaded
before the system starts, and cannot be unloaded).</para>
</sect2>
<sect2 id="mac-framework-kernel-arch-registration">
<title>Policy Registration</title>
<para>The MAC Framework maintains two lists of active
policies: a static list, and a dynamic list. The lists
differ only with regards to their locking semantics: an
elevated reference count is not required to make use of
the static list. When kernel modules containing MAC
Framework policies are loaded, the policy module will
use <literal>SYSINIT</literal> to invoke a registration
function; when a policy module is unloaded,
<literal>SYSINIT</literal> will likewise invoke a
de-registration function. Registration may fail if a
policy module is loaded more than once, if insufficient
resources are available for the registration (for
example, the policy might require labeling and
insufficient labeling state might be available), or
other policy prerequisites might not be met (some
policies may only be loaded prior to boot). Likewise,
de-registration may fail if a policy refuses an
unload.</para>
</sect2>
<sect2 id="mac-framework-kernel-arch-entrypoints">
<title>Entry Points</title>
<para>Kernel services interact with the MAC Framework in two ways:
they invoke a series of APIs to notify the framework of relevant
events, and they a policy-agnostic label structure in
security-relevant objects. This label structure is maintained by
the MAC Framework via label management entry points, and permits
the Framework to offer a labeling service to policy modules
through relatively non-invasive changes to the kernel subsystem
maintaining the object. For example, label structures have been
added to processes, process credentials, sockets, pipes, vnodes,
Mbufs, network interfaces, IP reassembly queues, and a variety
of other security-relevant structures. Kernel services also
invoke the MAC Framework when they perform important security
decisions, permitting policy modules to augment those decisions
based on their own criteria (possibly including data stored in
security labels).</para>
</sect2>
<sect2 id="mac-framework-kernel-arch-composition">
<title>Policy Composition</title>
<para>When more than one policy module is loaded into the kernel
at a time, the results of the policy modules will be composed
by the framework using a composition operator. This operator
is currently hard-coded, and requires that all active policies
must approve a request for it to occur. As policies may
return a variety of error conditions (success, access denied,
object doesn't exist, ...), a precedence operator selects the
resulting error from the set of errors returned by policies.
While it is not guaranteed that the resulting composition will
be useful or secure, we've found that it is for many useful
selections of policies.</para>
</sect2>
<sect2 id="mac-framework-kernel-arch-labels">
<title>Labeling Support</title>
<para>As many interesting access control extensions rely on
security labels on objects, the MAC Framework provides a set
of policy-agnostic label management system calls covering
a variety of user-exposed objects. Common label types
include partition identifiers, sensitivity labels, integrity
labels, compartments, domains, roles, and types. Policy
modules participate in the internalization and externalization
of string-based labels provides by user applications, and can
expose multiple label elements to applications if desired.</para>
<para>In-memory labels are stored in <structname>struct
label</structname>, which consists of a fixed-length array
of unions, each holding a <literal>void *</literal> pointer
and a <literal>long</literal>. Policies registering for
label storage will be assigned a "slot" identifier, which
may be used to dereference the label storage. The semantics
of the storage are left entirely up to the policy module:
modules are provided with a variety of entry points
associated with the kernel object life cycle, including
initialization, association/creation, and destruction. Using
these interfaces, it is possible to implement reference
counting and other storage mechanisms. Direct access to
the kernel object is generally not required by policy
modules to retrieve a label, as the MAC Framework generally
passes both a pointer to the object and a direct pointer
to the object's label into entry points.</para>
<para>Initialization entry points frequently include a blocking
disposition flag indicating whether or not an initialization
is permitted to block; if blocking is not permitted, a failure
may be returned to cancel allocation of the label. This may
occur, for example, in the network stack during interrupt
handling, where blocking is not permitted. Due to the
performance cost of maintaining labels on in-flight network
packets (Mbufs), policies must specifically declare a
requirement that Mbuf labels be allocated. Dynamically
loaded policies making use of labels must be able to handle
the case where their init function has not been called on
an object, as objects may already exist when the policy is
loaded.</para>
<para>In the case of file system labels, special support is
provided for the persistent storage of security labels in
extended attributes. Where available, EA transactions
are used to permit consistent compound updates of
security labels on vnodes.</para>
<note><para>Currently, if a labeled policy permits dynamic
unloading, its state slot cannot be reclaimed.</para></note>
</sect2>
<sect2 id="mac-framework-kernel-arch-syscalls">
<title>System Calls</title>
<para>The MAC Framework implements a number of system calls:
most of these calls support the policy-agnostic label
retrieval and manipulation APIs exposed to user
applications.</para>
<para>The label management calls accept a label description
structure, <structname>struct mac</structname>, which
contains a series of MAC label elements. Each element
contains a character string name, and character string
value. Each policy will be given the chance to claim a
particular element name, permitting policies to expose
multiple independent elements if desired. Policy modules
perform the internalization and externalization between
kernel labels and user-provided labels via entry points,
permitting a variety of semantics. Label management system
calls are generally wrapped by user library functions to
perform memory allocation and error handling.</para>
<para>In addition, <function>mac_syscall()</function>
permits policy modules to create new system calls without
allocating system calls. <function>mac_execve()</function>
permits an atomic process credential label change when
executing a new image.</para>
</sect2>
</sect1>
<sect1 id="mac-policy-architecture">
<title>MAC Policy Architecture</title>
<para>Security policies are either linked directly into the kernel,
or compiled into loadable kernel modules that may be loaded at
boot, or dynamically using the module loading system calls at
runtime. Policy modules interact with the system through a
set of declared entry points, providing access to a stream of
system events and permitting the policy to influence access
control decisions. Each policy contains a number of elements:</para>
<itemizedlist>
<listitem><para>Optional configuration parameters for
policy.</para></listitem>
<listitem><para>Centralized implementation of the policy
logic and parameters.</para></listitem>
<listitem><para>Optional implementation of policy life cycle
events, such as initialization and destruction.</para></listitem>
<listitem><para>Optional support for initializing, maintaining, and
destroying labels on selected kernel objects.</para></listitem>
<listitem><para>Optional support for user process inspection and
modification of labels on selected objects.</para></listitem>
<listitem><para>Implementation of selected access control
entry points that are of interest to the policy.</para></listitem>
<listitem><para>Declaration of policy identity, module entry
points, and policy properties.</para></listitem>
</itemizedlist>
<sect2 id="mac-policy-declaration">
<title>Policy Declaration</title>
<para>Modules may be declared using the
<function>MAC_POLICY_SET()</function> macro, which names the
policy, provides a reference to the MAC entry point vector,
provides load-time flags determining how the policy framework
should handle the policy, and optionally requests the
allocation of label state by the framework.</para>
<programlisting>static struct mac_policy_ops mac_<replaceable>policy</replaceable>_ops =
{
.mpo_destroy = mac_<replaceable>policy</replaceable>_destroy,
.mpo_init = mac_<replaceable>policy</replaceable>_init,
.mpo_init_bpfdesc_label = mac_<replaceable>policy</replaceable>_init_bpfdesc_label,
.mpo_init_cred_label = mac_<replaceable>policy</replaceable>_init_label,
/* ... */
.mpo_check_vnode_setutimes = mac_<replaceable>policy</replaceable>_check_vnode_setutimes,
.mpo_check_vnode_stat = mac_<replaceable>policy</replaceable>_check_vnode_stat,
.mpo_check_vnode_write = mac_<replaceable>policy</replaceable>_check_vnode_write,
};</programlisting>
<para>The MAC policy entry point vector,
<varname>mac_<replaceable>policy</replaceable>_ops</varname> in this example, associates
functions defined in the module with specific entry points. A
complete listing of available entry points and their
prototypes may be found in the MAC entry point reference
section. Of specific interest during module registration are
the <symbol>.mpo_destroy</symbol> and <symbol>.mpo_init</symbol>
entry points. <symbol>.mpo_init</symbol> will be invoked once a
policy is successfully registered with the module framework
but prior to any other entry points becoming active. This
permits the policy to perform any policy-specific allocation
and initialization, such as initialization of any data or
locks. <symbol>.mpo_destroy</symbol> will be invoked when a
policy module is unloaded to permit releasing of any allocated
memory and destruction of locks. Currently, these two entry
points are invoked with the MAC policy list mutex held to
prevent any other entry points from being invoked: this will
be changed, but in the mean time, policies should be careful
about what kernel primitives they invoke so as to avoid lock
ordering or sleeping problems.</para>
<para>The policy declaration's module name field exists so that
the module may be uniquely identified for the purposes of
module dependencies. An appropriate string should be selected.
The full string name of the policy is displayed to the user
via the kernel log during load and unload events, and also
exported when providing status information to userland
processes.</para>
</sect2>
<sect2 id="mac-policy-flags">
<title>Policy Flags</title>
<para>The policy declaration flags field permits the module to
provide the framework with information about its capabilities at
the time the module is loaded. Currently, three flags are
defined:</para>
<variablelist>
<varlistentry>
<term>MPC_LOADTIME_FLAG_UNLOADOK</term>
<listitem>
<para>This flag indicates that the policy module may be
unloaded. If this flag is not provided, then the policy
framework will reject requests to unload the module.
This flag might be used by modules that allocate label
state and are unable to free that state at
runtime.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>MPC_LOADTIME_FLAG_NOTLATE</term>
<listitem>
<para>This flag indicates that the policy module
must be loaded and initialized early in the boot
process. If the flag is specified, attempts to register
the module following boot will be rejected. The flag
may be used by policies that require pervasive labeling
of all system objects, and cannot handle objects that
have not been properly initialized by the policy.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>MPC_LOADTIME_FLAG_LABELMBUFS</term>
<listitem>
<para>This flag indicates that the policy module requires
labeling of Mbufs, and that memory should always be
allocated for the storage of Mbuf labels. By default,
the MAC Framework will not allocate label storage for
Mbufs unless at least one loaded policy has this flag
set. This measurably improves network performance when
policies do not require Mbuf labeling. A kernel option,
<literal>MAC_ALWAYS_LABEL_MBUF</literal>, exists to
force the MAC Framework to allocate Mbuf label storage
regardless of the setting of this flag, and may be
useful in some environments.</para>
</listitem>
</varlistentry>
</variablelist>
<note><para>Policies using the
<literal>MPC_LOADTIME_FLAG_LABELMBUFS</literal> without the
<literal>MPC_LOADTIME_FLAG_NOTLATE</literal> flag set
must be able to correctly handle <literal>NULL</literal>
Mbuf label pointers passed into entry points. This is necessary
as in-flight Mbufs without label storage may persist after a
policy enabling Mbuf labeling has been loaded. If a policy
is loaded before the network subsystem is active (i.e., the
policy is not being loaded late), then all Mbufs are guaranteed
to have label storage.</para></note>
</sect2>
<sect2 id="mac-policy-entry-points">
<title>Policy Entry Points</title>
<para>Four classes of entry points are offered to policies
registered with the framework: entry points associated with
the registration and management of policies, entry points
denoting initialization, creation, destruction, and other life
cycle events for kernel objects, events associated with access
control decisions that the policy module may influence, and
calls associated with the management of labels on objects. In
addition, a <function>mac_syscall()</function> entry point is
provided so that policies may extend the kernel interface
without registering new system calls.</para>
<para>Policy module writers should be aware of the kernel
locking strategy, as well as what object locks are available
during which entry points. Writers should attempt to avoid
deadlock scenarios by avoiding grabbing non-leaf locks inside
of entry points, and also follow the locking protocol for
object access and modification. In particular, writers should
be aware that while necessary locks to access objects and
their labels are generally held, sufficient locks to modify an
object or its label may not be present for all entry points.
Locking information for arguments is documented in the MAC
framework entry point document.</para>
<para>Policy entry points will pass a reference to the object
label along with the object itself. This permits labeled
policies to be unaware of the internals of the object yet
still make decisions based on the label. The exception to this
is the process credential, which is assumed to be understood
by policies as a first class security object in the kernel.
Policies that do not implement labels on kernel objects will
be passed NULL pointers for label arguments to entry
points.</para>
</sect2>
</sect1>
<sect1 id="mac-entry-point-reference">
<title>MAC Policy Entry Point Reference</title>
<sect2 id="mac-mpo-general">
<title>General-Purpose Module Entry Points</title>
<sect3 id="mac-mpo-init">
<title><function>&mac.mpo;_init</function</title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init</function></funcdef>
<paramdef>struct mac_policy_conf
*<parameter>conf</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>conf</parameter></entry>
<entry>MAC policy definition</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Policy load event. The policy list mutex is held, so
caution should be applied.</para>
</sect3>
<sect3 id="mpo-destroy">
<title><function>&mac.mpo;_destroy</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy</function></funcdef>
<paramdef>struct mac_policy_conf
*<parameter>conf</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>conf</parameter></entry>
<entry>MAC policy definition</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Policy load event. The policy list mutex is held, so
caution should be applied.</para>
</sect3>
<sect3 id="mac-mpo-syscall">
<title><function>&mac.mpo;_syscall</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_syscall</function></funcdef>
<paramdef>struct thread
*<parameter>td</parameter></paramdef>
<paramdef>int <parameter>call</parameter></paramdef>
<paramdef>void *<parameter>arg</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>td</parameter></entry>
<entry>Calling thread</entry>
</row>
<row>
<entry><parameter>call</parameter></entry>
<entry>Syscall number</entry>
</row>
<row>
<entry><parameter>arg</parameter></entry>
<entry>Pointer to syscall arguments</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>This entry point provides a policy-multiplexed system
call so that policies may provide additional services to
user processes without registering specific system calls.
The policy name provided during registration is used to
demux calls from userland, and the arguments will be
forwarded to this entry point. When implementing new
services, security modules should be sure to invoke
appropriate access control checks from the MAC framework as
needed. For example, if a policy implements an augmented
signal functionality, it should call the necessary signal
access control checks to invoke the MAC framework and other
registered policies.</para>
<note><para>Modules must currently perform the
<function>copyin()</function> of the syscall data on their
own.</para></note>
</sect3>
<sect3 id="mac-mpo-thread-userret">
<title><function>&mac.mpo;_thread_userret</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_thread_userret</function></funcdef>
<paramdef>struct thread
*<parameter>td</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>td</parameter></entry>
<entry>Returning thread</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<!-- XXX: Maybe rewrite this section. -->
<para>This entry point 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.</para>
</sect3>
</sect2>
<sect2 id="mac-label-ops">
<title>Label Operations</title>
<sect3 id="mac-mpo-init-bpfdesc">
<title><function>&mac.mpo;_init_bpfdesc_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_bpfdesc_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to apply</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label on a newly instantiated bpfdesc (BPF
descriptor)</para>
</sect3>
<sect3 id="mac-mpo-init-cred-label">
<title><function>&mac.mpo;_init_cred_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_cred_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to initialize</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label for a newly instantiated
user credential.</para>
</sect3>
<sect3 id="mac-mpo-init-devfsdirent">
<title><function>&mac.mpo;_init_devfsdirent_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_devfsdirent_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to apply</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label on a newly instantiated devfs
entry.</para>
</sect3>
<sect3 id="mac-mpo-init-ifnet">
<title><function>&mac.mpo;_init_ifnet_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_ifnet_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to apply</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label on a newly instantiated network
interface.</para>
</sect3>
<sect3 id="mac-mpo-init-ipq">
<title><function>&mac.mpo;_init_ipq_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_ipq_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int <parameter>flag</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to apply</entry>
</row>
<row>
<entry><parameter>flag</parameter></entry>
<entry>Blocking/non-blocking &man.malloc.9;; see
below</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label on a newly instantiated IP fragment
reassembly queue. The <parameter>flag</parameter> field may
be one of <symbol>M_WAITOK</symbol> and <symbol>M_NOWAIT</symbol>,
and should be employed to avoid performing a blocking
&man.malloc.9; during this initialization call. IP fragment
reassembly queue allocation frequently occurs in performance
sensitive environments, and the implementation should be careful
to avoid blocking or long-lived operations. This entry point
is permitted to fail resulting in the failure to allocate
the IP fragment reassembly queue.</para>
</sect3>
<sect3 id="mac-mpo-init-mbuf">
<title><function>&mac.mpo;_init_mbuf_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_mbuf_label</function></funcdef>
<paramdef>int <parameter>flag</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>flag</parameter></entry>
<entry>Blocking/non-blocking &man.malloc.9;; see
below</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label to initialize</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label on a newly instantiated mbuf packet
header (<parameter>mbuf</parameter>). The
<parameter>flag</parameter> field may be one of
<symbol>M_WAITOK</symbol> and <symbol>M_NOWAIT</symbol>, and
should be employed to avoid performing a blocking
&man.malloc.9; during this initialization call. Mbuf
allocation frequently occurs in performance sensitive
environments, and the implementation should be careful to
avoid blocking or long-lived operations. This entry point
is permitted to fail resulting in the failure to allocate
the mbuf header.</para>
</sect3>
<sect3 id="mac-mpo-init-mount">
<title><function>&mac.mpo;_init_mount_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_mount_label</function></funcdef>
<paramdef>struct label
*<parameter>mntlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<!-- XXX: Wording on label descriptions. -->
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>mntlabel</parameter></entry>
<entry>Policy label to be initialized for the mount
itself</entry>
</row>
<row>
<entry><parameter>fslabel</parameter></entry>
<entry>Policy label to be initialized for the file
system</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the labels on a newly instantiated mount
point.</para>
</sect3>
<sect3 id="mac-mpo-init-mount-fs-label">
<title><function>&mac.mpo;_init_mount_fs_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_mount_fs_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label to be initialized</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label on a newly mounted file
system.</para>
</sect3>
<sect3 id="mac-mpo-init-pipe-label">
<title><function>&mac.mpo;_init_pipe_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_pipe_label</function></funcdef>
<paramdef>struct
label*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label to be filled in</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize a label for a newly instantiated pipe.</para>
</sect3>
<sect3 id="mac-mpo-init-socket">
<title><function>&mac.mpo;_init_socket_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_socket_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int <parameter>flag</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to initialize</entry>
</row>
<row>
<entry><parameter>flag</parameter></entry>
<entry>&man.malloc.9; flags</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize a label for a newly instantiated
socket.</para>
</sect3>
<sect3 id="mac-mpo-init-socket-peer-label">
<title><function>&mac.mpo;_init_socket_peer_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_socket_peer_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int <parameter>flag</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to initialize</entry>
</row>
<row>
<entry><parameter>flag</parameter></entry>
<entry>&man.malloc.9; flags</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the peer label for a newly instantiated
socket.</para>
</sect3>
<sect3 id="mac-mpo-init-proc-label">
<title><function>&mac.mpo;_init_proc_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_proc_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to initialize</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label for a newly instantiated
process.</para>
</sect3>
<sect3 id="mac-mpo-init-vnode">
<title><function>&mac.mpo;_init_vnode_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_init_vnode_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>New label to initialize</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Initialize the label on a newly instantiated vnode.</para>
</sect3>
<sect3 id="mac-mpo-destroy-bpfdesc">
<title><function>&mac.mpo;_destroy_bpfdesc_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_bpfdesc_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>bpfdesc label</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a BPF descriptor. In this entry
point a policy should free any internal storage associated
with <parameter>label</parameter> so that it may be
destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-cred">
<title><function>&mac.mpo;_destroy_cred_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_cred_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a credential. In this entry point,
a policy module should free any internal storage associated
with <parameter>label</parameter> so that it may be
destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-devfsdirent">
<title><function>&mac.mpo;_destroy_devfsdirent_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_devfsdirent_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a devfs entry. In this entry
point, a policy module should free any internal storage
associated with <parameter>label</parameter> so that it may
be destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-ifnet-label">
<title><function>&mac.mpo;_destroy_ifnet_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_ifnet_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a removed interface. In this entry
point, a policy module should free any internal storage
associated with <parameter>label</parameter> so that it may
be destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-ipq-label">
<title><function>&mac.mpo;_destroy_ipq_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_ipq_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on an IP fragment queue. In this
entry point, a policy module should free any internal
storage associated with <parameter>label</parameter> so that
it may be destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-mbuf-label">
<title><function>&mac.mpo;_destroy_mbuf_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_mbuf_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on an mbuf header. In this entry
point, a policy module should free any internal storage
associated with <parameter>label</parameter> so that it may
be destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-mount-label">
<title><function>&mac.mpo;_destroy_mount_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_mount_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Mount point label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the labels on a mount point. In this entry
point, a policy module should free the internal storage
associated with <parameter>mntlabel</parameter> so that they
may be destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-mount">
<title><function>&mac.mpo;_destroy_mount_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_mount_label</function></funcdef>
<paramdef>struct label
*<parameter>mntlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>mntlabel</parameter></entry>
<entry>Mount point label being destroyed</entry>
</row>
<row>
<entry><parameter>fslabel</parameter></entry>
<entry>File system label being destroyed></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the labels on a mount point. In this entry
point, a policy module should free the internal storage
associated with <parameter>mntlabel</parameter> and
<parameter>fslabel</parameter> so that they may be
destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-socket">
<title><function>&mac.mpo;_destroy_socket_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_socket_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Socket label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a socket. In this entry point, a
policy module should free any internal storage associated
with <parameter>label</parameter> so that it may be
destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-socket-peer-label">
<title><function>&mac.mpo;_destroy_socket_peer_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_socket_peer_label</function></funcdef>
<paramdef>struct label
*<parameter>peerlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>peerlabel</parameter></entry>
<entry>Socket peer label being destroyed</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the peer label on a socket. In this entry
point, a policy module should free any internal storage
associated with <parameter>label</parameter> so that it may
be destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-pipe-label">
<title><function>&mac.mpo;_destroy_pipe_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_pipe_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Pipe label</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a pipe. In this entry point, a
policy module should free any internal storage associated
with <parameter>label</parameter> so that it may be
destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-proc-label">
<title><function>&mac.mpo;_destroy_proc_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_proc_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Process label</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a process. In this entry point, a
policy module should free any internal storage associated
with <parameter>label</parameter> so that it may be
destroyed.</para>
</sect3>
<sect3 id="mac-mpo-destroy-vnode-label">
<title><function>&mac.mpo;_destroy_vnode_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_destroy_vnode_label</function></funcdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>label</parameter></entry>
<entry>Process label</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Destroy the label on a vnode. In this entry point, a
policy module should free any internal storage associated
with <parameter>label</parameter> so that it may be
destroyed.</para>
</sect3>
<sect3 id="mac-mpo-copy-mbuf-label">
<title><function>&mac.mpo;_copy_mbuf_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_copy_mbuf_label</function></funcdef>
<paramdef>struct label
*<parameter>src</parameter></paramdef>
<paramdef>struct label
*<parameter>dest</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>src</parameter></entry>
<entry>Source label</entry>
</row>
<row>
<entry><parameter>dest</parameter></entry>
<entry>Destination label</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Copy the label information in
<parameter>src</parameter> into
<parameter>dest</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-copy-pipe-label">
<title><function>&mac.mpo;_copy_pipe_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_copy_pipe_label</function></funcdef>
<paramdef>struct label
*<parameter>src</parameter></paramdef>
<paramdef>struct label
*<parameter>dest</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>src</parameter></entry>
<entry>Source label</entry>
</row>
<row>
<entry><parameter>dest</parameter></entry>
<entry>Destination label</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Copy the label information in
<parameter>src</parameter> into
<parameter>dest</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-copy-vnode-label">
<title><function>&mac.mpo;_copy_vnode_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_copy_vnode_label</function></funcdef>
<paramdef>struct label
*<parameter>src</parameter></paramdef>
<paramdef>struct label
*<parameter>dest</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>src</parameter></entry>
<entry>Source label</entry>
</row>
<row>
<entry><parameter>dest</parameter></entry>
<entry>Destination label</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Copy the label information in
<parameter>src</parameter> into
<parameter>dest</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-externalize-cred-label">
<title><function>&mac.mpo;_externalize_cred_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_externalize_cred_label</function></funcdef>
&mac.externalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.externalize.tbody;
</tgroup>
</informaltable>
&mac.externalize.para;
</sect3>
<sect3 id="mac-mpo-externalize-ifnet-label">
<title><function>&mac.mpo;_externalize_ifnet_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_externalize_ifnet_label</function></funcdef>
&mac.externalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.externalize.tbody;
</tgroup>
</informaltable>
&mac.externalize.para;
</sect3>
<sect3 id="mac-mpo-externalize-pipe-label">
<title><function>&mac.mpo;_externalize_pipe_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_externalize_pipe_label</function></funcdef>
&mac.externalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.externalize.tbody;
</tgroup>
</informaltable>
&mac.externalize.para;
</sect3>
<sect3 id="mac-mpo-externalize-socket-label">
<title><function>&mac.mpo;_externalize_socket_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_externalize_socket_label</function></funcdef>
&mac.externalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.externalize.tbody;
</tgroup>
</informaltable>
&mac.externalize.para;
</sect3>
<sect3 id="mac-mpo-externalize-socket-peer-label">
<title><function>&mac.mpo;_externalize_socket_peer_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_externalize_socket_peer_label</function></funcdef>
&mac.externalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.externalize.tbody;
</tgroup>
</informaltable>
&mac.externalize.para;
</sect3>
<sect3 id="mac-mpo-externalize-vnode-label">
<title><function>&mac.mpo;_externalize_vnode_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_externalize_vnode_label</function></funcdef>
&mac.externalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.externalize.tbody;
</tgroup>
</informaltable>
&mac.externalize.para;
</sect3>
<sect3 id="mac-mpo-internalize-cred-label">
<title><function>&mac.mpo;_internalize_cred_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_internalize_cred_label</function></funcdef>
&mac.internalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.internalize.tbody;
</tgroup>
</informaltable>
&mac.internalize.para;
</sect3>
<sect3 id="mac-mpo-internalize-ifnet-label">
<title><function>&mac.mpo;_internalize_ifnet_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_internalize_ifnet_label</function></funcdef>
&mac.internalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.internalize.tbody;
</tgroup>
</informaltable>
&mac.internalize.para;
</sect3>
<sect3 id="mac-mpo-internalize-pipe-label">
<title><function>&mac.mpo;_internalize_pipe_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_internalize_pipe_label</function></funcdef>
&mac.internalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.internalize.tbody;
</tgroup>
</informaltable>
&mac.internalize.para;
</sect3>
<sect3 id="mac-mpo-internalize-socket-label">
<title><function>&mac.mpo;_internalize_socket_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_internalize_socket_label</function></funcdef>
&mac.internalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.internalize.tbody;
</tgroup>
</informaltable>
&mac.internalize.para;
</sect3>
<sect3 id="mac-mpo-internalize-vnode-label">
<title><function>&mac.mpo;_internalize_vnode_label</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_internalize_vnode_label</function></funcdef>
&mac.internalize.paramdefs;
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
&mac.internalize.tbody;
</tgroup>
</informaltable>
&mac.internalize.para;
</sect3>
</sect2>
<sect2 id="mac-label-events">
<title>Label Events</title>
<para>This class of entry points is used by the MAC framework to
permit policies to maintain label information on kernel
objects. For each labeled kernel object of interest to a MAC
policy, entry points may be registered for relevant life cycle
events. All objects implement initialization, creation, and
destruction hooks. Some objects will also implement
relabeling, allowing user processes to change the labels on
objects. Some objects will also implement object-specific
events, such as label events associated with IP reassembly. A
typical labeled object will have the following life cycle of
entry points:</para>
<programlisting>Label initialization o
(object-specific wait) \
Label creation o
\
Relabel events, o--<--.
Various object-specific, | |
Access control events ~-->--o
\
Label destruction o</programlisting>
<para>Label initialization permits policies to allocate memory
and set initial values for labels without context for the use
of the object. The label slot allocated to a policy will be
zeroed by default, so some policies may not need to perform
initialization.</para>
<para>Label creation occurs when the kernel structure is
associated with an actual kernel object. For example, Mbufs
may be allocated and remain unused in a pool until they are
required. mbuf allocation causes label initialization on the
mbuf to take place, but mbuf creation occurs when the mbuf is
associated with a datagram. Typically, context will be
provided for a creation event, including the circumstances of
the creation, and labels of other relevant objects in the
creation process. For example, when an mbuf is created from a
socket, the socket and its label will be presented to
registered policies in addition to the new mbuf and its label.
Memory allocation in creation events is discouraged, as it may
occur in performance sensitive ports of the kernel; in
addition, creation calls are not permitted to fail so a
failure to allocate memory cannot be reported.</para>
<para>Object specific events do not generally fall into the
other broad classes of label events, but will generally
provide an opportunity to modify or update the label on an
object based on additional context. For example, the label on
an IP fragment reassembly queue may be updated during the
<symbol>MAC_UPDATE_IPQ</symbol> entry point as a result of the
acceptance of an additional mbuf to that queue.</para>
<para>Access control events are discussed in detail in the
following section.</para>
<para>Label destruction permits policies to release storage or
state associated with a label during its association with an
object so that the kernel data structures supporting the
object may be reused or released.</para>
<para>In addition to labels associated with specific kernel
objects, an additional class of labels exists: temporary
labels. These labels are used to store update information
submitted by user processes. These labels are initialized and
destroyed as with other label types, but the creation event is
<symbol>MAC_INTERNALIZE</symbol>, which accepts a user label
to be converted to an in-kernel representation.</para>
<sect3 id="mac-fs-label-event-ops">
<title>File System Object Labeling Event Operations</title>
<sect4 id="mac-mpo-associate-vnode-devfs">
<title><function>&mac.mpo;_associate_vnode_devfs</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_associate_vnode_devfs</function></funcdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
<paramdef>struct devfs_dirent
*<parameter>de</parameter></paramdef>
<paramdef>struct label
*<parameter>delabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>mp</parameter></entry>
<entry>Devfs mount point</entry>
</row>
<row>
<entry><parameter>fslabel</parameter></entry>
<entry>Devfs file system label
(<varname>mp->mnt_fslabel</varname>)</entry>
</row>
<row>
<entry><parameter>de</parameter></entry>
<entry>Devfs directory entry</entry>
</row>
<row>
<entry><parameter>delabel</parameter></entry>
<entry>Policy label associated with
<parameter>de</parameter></entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>vnode associated with
<parameter>de</parameter></entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Fill in the label (<parameter>vlabel</parameter>) for
a newly created devfs vnode based on the devfs directory
entry passed in <parameter>de</parameter> and its
label.</para>
</sect4>
<sect4 id="mac-mpo-associate-vnode-extattr">
<title><function>&mac.mpo;_associate_vnode_extattr</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_associate_vnode_extattr</function></funcdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>mp</parameter></entry>
<entry>File system mount point</entry>
</row>
<row>
<entry><parameter>fslabel</parameter></entry>
<entry>File system label</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Vnode to label</entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Attempt to retrieve the label for
<parameter>vp</parameter> from the file system extended
attributes. Upon success, the value <literal>0</literal>
is returned. Should extended attribute retrieval not be
supported, an accepted fallback is to copy
<parameter>fslabel</parameter> into
<parameter>vlabel</parameter>. In the event of an error,
an appropriate value for <varname>errno</varname> should
be returned.</para>
</sect4>
<sect4 id="mac-mpo-associate-vnode-singlelabel">
<title><function>&mac.mpo;_associate_vnode_singlelabel</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_associate_vnode_singlelabel</function></funcdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>mp</parameter></entry>
<entry>File system mount point</entry>
</row>
<row>
<entry><parameter>fslabel</parameter></entry>
<entry>File system label</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Vnode to label</entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>On non-multilabel file systems, this entry point is
called to set the policy label for
<parameter>vp</parameter> based on the file system label,
<parameter>fslabel</parameter>.</para>
</sect4>
<sect4 id="mac-mpo-create-devfs-device">
<title><function>&mac.mpo;_create_devfs_device</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_devfs_device</function></funcdef>
<paramdef>dev_t <parameter>dev</parameter></paramdef>
<paramdef>struct devfs_dirent
*<parameter>devfs_dirent</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>dev</parameter></entry>
<entry>Device corresponding with
<parameter>devfs_dirent</parameter></entry>
</row>
<row>
<entry><parameter>devfs_dirent</parameter></entry>
<entry>Devfs directory entry to be labeled.</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Label for <parameter>devfs_dirent</parameter>
to be filled in.</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Fill out the label on a devfs_dirent being created for
the passed device. This call will be made when the device
file system is mounted, regenerated, or a new device is made
available.</para>
</sect4>
<sect4 id="mac-mpo-create-devfs-directory">
<title><function>&mac.mpo;_create_devfs_directory</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_devfs_directory</function></funcdef>
<paramdef>char *<parameter>dirname</parameter></paramdef>
<paramdef>int <parameter>dirnamelen</parameter></paramdef>
<paramdef>struct devfs_dirent
*<parameter>devfs_dirent</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>dirname</parameter></entry>
<entry>Name of directory being created</entry>
</row>
<row>
<entry><parameter>namelen</parameter></entry>
<entry>Length of string
<parameter>dirname</parameter></entry>
</row>
<row>
<entry><parameter>devfs_dirent</parameter></entry>
<entry>Devfs directory entry for directory being
created.</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Fill out the label on a devfs_dirent being created for
the passed directory. This call will be made when the device
file system is mounted, regenerated, or a new device
requiring a specific directory hierarchy is made
available.</para>
</sect4>
<sect4 id="mac-mpo-create-devfs-symlink">
<title><function>&mac.mpo;_create_devfs_symlink</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_devfs_symlink</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct devfs_dirent
*<parameter>dd</parameter></paramdef>
<paramdef>struct label
*<parameter>ddlabel</parameter></paramdef>
<paramdef>struct devfs_dirent
*<parameter>de</parameter></paramdef>
<paramdef>struct label
*<parameter>delabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>mp</parameter></entry>
<entry>Devfs mount point</entry>
</row>
<row>
<entry><parameter>dd</parameter></entry>
<entry>Link destination</entry>
</row>
<row>
<entry><parameter>ddlabel</parameter></entry>
<entry>Label associated with
<parameter>dd</parameter></entry>
</row>
<row>
<entry><parameter>de</parameter></entry>
<entry>Symlink entry</entry>
</row>
<row>
<entry><parameter>delabel</parameter></entry>
<entry>Label associated with
<parameter>de</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Fill in the label (<parameter>delabel</parameter>) for
a newly created &man.devfs.5; symbolic link entry.</para>
</sect4>
<sect4 id="mac-mpo-create-vnode-extattr">
<title><function>&mac.mpo;_create_vnode_extattr</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_create_vnode_extattr</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
<paramdef>struct componentname
*<parameter>cnp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>mount</parameter></entry>
<entry>File system mount point</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>File system label</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Parent directory vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Label associated with
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Newly created vnode</entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>cnp</parameter></entry>
<entry>Component name for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Write out the label for <parameter>vp</parameter> to
the appropriate extended attribute. If the write
succeeds, fill in <parameter>vlabel</parameter> with the
label, and return <returnvalue>0</returnvalue>. Otherwise,
return an appropriate error.</para>
</sect4>
<sect4 id="mac-mpo-create-mount">
<title><function>&mac.mpo;_create_mount</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mount</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct label
*<parameter>mnt</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>mp</parameter></entry>
<entry>Object; file system being mounted</entry>
</row>
<row>
<entry><parameter>mntlabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>mp</parameter></entry>
</row>
<row>
<entry><parameter>fslabel</parameter></entry>
<entry>Policy label for the file system
<parameter>mp</parameter> mounts.</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Fill out the labels on the mount point being created by
the passed subject credential. This call will be made when
a new file system is mounted.</para>
</sect4>
<sect4 id="mac-mpo-create-root-mount">
<title><function>&mac.mpo;_create_root_mount</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_root_mount</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct label
*<parameter>mntlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>fslabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry namest="first" nameend="last">See <xref
linkend="mac-mpo-create-mount">.</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Fill out the labels on the mount point being created by
the passed subject credential. This call will be made when
the root file system is mounted, after
&mac.mpo;_create_mount;.</para>
</sect4>
<sect4 id="mac-mpo-relabel-vnode">
<title><function>&mac.mpo;_relabel_vnode</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_relabel_vnode</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vnodelabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>vnode to relabel</entry>
</row>
<row>
<entry><parameter>vnodelabel</parameter></entry>
<entry>Existing policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>New, possibly partial label to replace
<parameter>vnodelabel</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Update the label on the passed vnode given the passed
update vnode label and the passed subject credential.</para>
</sect4>
<sect4 id="mac-mpo-setlabel-vnode-extattr">
<title><function>&mac.mpo;_setlabel_vnode_extattr</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_setlabel_vnode_extattr</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>intlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Vnode for which the label is being
written</entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>intlabel</parameter></entry>
<entry>Label to write out</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Write out the policy from
<parameter>intlabel</parameter> to an extended
attribute. This is called from
<function>vop_stdcreatevnode_ea</function>.</para>
</sect4>
<sect4 id="mac-mpo-update-devfsdirent">
<title><function>&mac.mpo;_update_devfsdirent</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_update_devfsdirent</function></funcdef>
<paramdef>struct devfs_dirent
*<parameter>devfs_dirent</parameter></paramdef>
<paramdef>struct label
*<parameter>direntlabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vnodelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>devfs_dirent</parameter></entry>
<entry>Object; devfs directory entry</entry>
</row>
<row>
<entry><parameter>direntlabel</parameter></entry>
<entry>Policy label for
<parameter>devfs_dirent</parameter> to be
updated.</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Parent vnode</entry>
<entry>Locked</entry>
</row>
<row>
<entry><parameter>vnodelabel</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Update the <parameter>devfs_dirent</parameter> label
from the passed devfs vnode label. This call will be made
when a devfs vnode has been successfully relabeled to commit
the label change such that it lasts even if the vnode is
recycled. It will also be made when when a symlink is
created in devfs, following a call to
<function>mac_vnode_create_from_vnode</function> to
initialize the vnode label.</para>
</sect4>
</sect3>
<sect3 id="mac-ipc-label-ops">
<title>IPC Object Labeling Event Operations</title>
<sect4 id="mac-mpo-create-mbuf-from-socket">
<title><function>&mac.mpo;_create_mbuf_from_socket</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mbuf_from_socket</function></funcdef>
<paramdef>struct socket
*<parameter>so</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
<paramdef>struct mbuf *<parameter>m</parameter></paramdef>
<paramdef>struct label
*<parameter>mbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>socket</parameter></entry>
<entry>Socket</entry>
<entry>Socket locking WIP</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label for
<parameter>socket</parameter></entry>
</row>
<row>
<entry><parameter>m</parameter></entry>
<entry>Object; mbuf</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Policy label to fill in for
<parameter>m</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on a newly created mbuf header from the
passed socket label. This call is made when a new datagram
or message is generated by the socket and stored in the
passed mbuf.</para>
</sect4>
<sect4 id="mac-mpo-create-pipe">
<title><function>&mac.mpo;_create_pipe</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_pipe</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>pipelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>pipelabel</parameter></entry>
<entry>Policy label associated with
<parameter>pipe</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on a newly created pipe from the passed
subject credential. This call is made when a new pipe is
created.</para>
</sect4>
<sect4 id="mac-mpo-create-socket">
<title><function>&mac.mpo;_create_socket</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_socket</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>so</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>so</parameter></entry>
<entry>Object; socket to label</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Label to fill in for
<parameter>so</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on a newly created socket from the passed
subject credential. This call is made when a socket is
created.</para>
</sect4>
<sect4 id="mac-mpo-create-socket-from-socket">
<title><function>&mac.mpo;_create_socket_from_socket</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_socket_from_socket</function></funcdef>
<paramdef>struct socket
*<parameter>oldsocket</parameter></paramdef>
<paramdef>struct label
*<parameter>oldsocketlabel</parameter></paramdef>
<paramdef>struct socket
*<parameter>newsocket</parameter></paramdef>
<paramdef>struct label
*<parameter>newsocketlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>oldsocket</parameter></entry>
<entry>Listening socket</entry>
</row>
<row>
<entry><parameter>oldsocketlabel</parameter></entry>
<entry>Policy label associated with
<parameter>oldsocket</parameter></entry>
</row>
<row>
<entry><parameter>newsocket</parameter></entry>
<entry>New socket</entry>
</row>
<row>
<entry><parameter>newsocketlabel</parameter></entry>
<entry>Policy label associated with
<parameter>newsocketlabel</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Label a socket, <parameter>newsocket</parameter>,
newly &man.accept.2;ed, based on the &man.listen.2;
socket, <parameter>oldsocket</parameter>.</para>
</sect4>
<sect4 id="mac-mpo-relabel-pipe">
<title><function>&mac.mpo;_relabel_pipe</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_relabel_pipe</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>oldlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>oldlabel</parameter></entry>
<entry>Current policy label associated with
<parameter>pipe</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Policy label update to apply to
<parameter>pipe</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Apply a new label, <parameter>newlabel</parameter>, to
<parameter>pipe</parameter>.</para>
</sect4>
<sect4 id="mac-mpo-relabel-socket">
<title><function>&mac.mpo;_relabel_socket</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_relabel_socket</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>so</parameter></paramdef>
<paramdef>struct label
*<parameter>oldlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>so</parameter></entry>
<entry>Object; socket</entry>
</row>
<row>
<entry><parameter>oldlabel</parameter></entry>
<entry>Current label for
<parameter>so</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Label update for
<parameter>so</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Update the label on a socket from the passed socket
label update.</para>
</sect4>
<sect4 id="mpo-set-socket-peer-from-mbuf">
<title><function>&mac.mpo;_set_socket_peer_from_mbuf</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_set_socket_peer_from_mbuf</function></funcdef>
<paramdef>struct mbuf
*<parameter>mbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>mbuflabel</parameter></paramdef>
<paramdef>struct label
*<parameter>oldlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>mbuf</parameter></entry>
<entry>First datagram received over socket</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Label for <parameter>mbuf</parameter></entry>
</row>
<row>
<entry><parameter>oldlabel</parameter></entry>
<entry>Current label for the socket</entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Policy label to be filled out for the
socket</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the peer label on a stream socket from the passed
mbuf label. This call will be made when the first datagram
is received by the stream socket, with the exception of Unix
domain sockets.</para>
</sect4>
<sect4 id="mac-mpo-set-socket-peer-from-socket">
<title><function>&mac.mpo;_set_socket_peer_from_socket</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_set_socket_peer_from_socket</function></funcdef>
<paramdef>struct socket
*<parameter>oldsocket</parameter></paramdef>
<paramdef>struct label
*<parameter>oldsocketlabel</parameter></paramdef>
<paramdef>struct socket
*<parameter>newsocket</parameter></paramdef>
<paramdef>struct label
*<parameter>newsocketpeerlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>oldsocket</parameter></entry>
<entry>Local socket</entry>
</row>
<row>
<entry><parameter>oldsocketlabel</parameter></entry>
<entry>Policy label for
<parameter>oldsocket</parameter></entry>
</row>
<row>
<entry><parameter>newsocket</parameter></entry>
<entry>Peer socket</entry>
</row>
<row>
<entry><parameter>newsocketpeerlabel</parameter></entry>
<entry>Policy label to fill in for
<parameter>newsocket</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<!-- XXX Passed _remote_ socket endpoint ? -->
<para>Set the peer label on a stream UNIX domain socket from
the passed remote socket endpoint. This call will be made
when the socket pair is connected, and will be made for both
endpoints.</para>
</sect4>
</sect3>
<sect3 id="mac-net-labeling-event-ops">
<title>Network Object Labeling Event Operations</title>
<sect4 id="mac-mpo-create-bpfdesc">
<title><function>&mac.mpo;_create_bpfdesc</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_bpfdesc</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct bpf_d
*<parameter>bpf_d</parameter></paramdef>
<paramdef>struct label
*<parameter>bpflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>bpf_d</parameter></entry>
<entry>Object; bpf descriptor</entry>
</row>
<row>
<entry><parameter>bpf</parameter></entry>
<entry>Policy label to be filled in for
<parameter>bpf_d</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on a newly created BPF descriptor from the
passed subject credential. This call will be made when a
BPF device node is opened by a process with the passed
subject credential.</para>
</sect4>
<sect4 id="mac-mpo-create-ifnet">
<title><function>&mac.mpo;_create_ifnet</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_ifnet</function></funcdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdeF>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label to fill in for
<parameter>ifnet</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on a newly created interface. This call
may be made when a new physical interface becomes available
to the system, or when a pseudo-interface is instantiated
during the boot or as a result of a user action.</para>
</sect4>
<sect4 id="mac-mpo-create-ipq">
<title><function>&mac.mpo;_create_ipq</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_ipq</function></funcdef>
<paramdef>struct mbuf
*<parameter>fragment</parameter></paramdef>
<paramdef>struct label
*<parameter>fragmentlabel</parameter></paramdef>
<paramdef>struct ipq
*<parameter>ipq</parameter></paramdef>
<paramdef>struct label
*<parameter>ipqlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>fragment</parameter></entry>
<entry>First received IP fragment</entry>
</row>
<row>
<entry><parameter>fragmentlabel</parameter></entry>
<entry>Policy label for
<parameter>fragment</parameter></entry>
</row>
<row>
<entry><parameter>ipq</parameter></entry>
<entry>IP reassembly queue to be labeled</entry>
</row>
<row>
<entry><parameter>ipqlabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>ipq</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on a newly created IP fragment reassembly
queue from the mbuf header of the first received
fragment.</para>
</sect4>
<sect4 id="mac-mpo-create-datagram-from-ipq">
<title><function>&mac.mpo;_create_datagram_from_ipq</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_create_datagram_from_ipq</function></funcdef>
<paramdef>struct ipq
*<parameter>ipq</parameter></paramdef>
<paramdef>struct label
*<parameter>ipqlabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>datagram</parameter></paramdef>
<paramdef>struct label
*<parameter>datagramlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>ipq</parameter></entry>
<entry>IP reassembly queue</entry>
</row>
<row>
<entry><parameter>ipqlabel</parameter></entry>
<entry>Policy label for
<parameter>ipq</parameter></entry>
</row>
<row>
<entry><parameter>datagram</parameter></entry>
<entry>Datagram to be labeled</entry>
</row>
<row>
<entry><parameter>datagramlabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>datagramlabel</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on a newly reassembled IP datagram from
the IP fragment reassembly queue from which it was
generated.</para>
</sect4>
<sect4 id="mac-mpo-create-fragment">
<title><function>&mac.mpo;_create_fragment</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_fragment</function></funcdef>
<paramdef>struct mbuf
*<parameter>datagram</parameter></paramdef>
<paramdef>struct label
*<parameter>datagramlabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>fragment</parameter></paramdef>
<paramdef>struct label
*<parameter>fragmentlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>datagram</parameter></entry>
<entry>Datagram</entry>
</row>
<row>
<entry><parameter>datagramlabel</parameter></entry>
<entry>Policy label for
<parameter>datagram</parameter></entry>
</row>
<row>
<entry><parameter>fragment</parameter></entry>
<entry>Fragment to be labeled</entry>
</row>
<row>
<entry><parameter>fragmentlabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>datagram</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on the mbuf header of a newly created IP
fragment from the label on the mbuf header of the datagram
it was generate from.</para>
</sect4>
<sect4 id="mac-mpo-create-mbuf-from-mbuf">
<title><function>&mac.mpo;_create_mbuf_from_mbuf</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mbuf_from_mbuf</function></funcdef>
<paramdef>struct mbuf
*<parameter>oldmbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>oldmbuflabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>newmbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>newmbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>oldmbuf</parameter></entry>
<entry>Existing (source) mbuf</entry>
</row>
<row>
<entry><parameter>oldmbuflabel</parameter></entry>
<entry>Policy label for
<parameter>oldmbuf</parameter></entry>
</row>
<row>
<entry><parameter>newmbuf</parameter></entry>
<entry>New mbuf to be labeled</entry>
</row>
<row>
<entry><parameter>newmbuflabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>newmbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on the mbuf header of a newly created
datagram from the mbuf header of an existing datagram. This
call may be made in a number of situations, including when
an mbuf is re-allocated for alignment purposes.</para>
</sect4>
<sect4 id="mac-mpo-create-mbuf-linklayer">
<title><function>&mac.mpo;_create_mbuf_linklayer</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mbuf_linklayer</function></funcdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>mbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>mbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label for
<parameter>ifnet</parameter></entry>
</row>
<row>
<entry><parameter>mbuf</parameter></entry>
<entry>mbuf header for new datagram</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>mbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on the mbuf header of a newly created
datagram generated for the purposes of a link layer response
for the passed interface. This call may be made in a number
of situations, including for ARP or ND6 responses in the
IPv4 and IPv6 stacks.</para>
</sect4>
<sect4 id="mac-mpo-create-mbuf-from-bpfdesc">
<title><function>&mac.mpo;_create_mbuf_from_bpfdesc</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mbuf_from_bpfdesc</function></funcdef>
<paramdef>struct bpf_d
*<parameter>bpf_d</parameter></paramdef>
<paramdef>struct label
*<parameter>bpflabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>mbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>mbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>bpf_d</parameter></entry>
<entry>BPF descriptor</entry>
</row>
<row>
<entry><parameter>bpflabel</parameter></entry>
<entry>Policy label for
<parameter>bpflabel</parameter></entry>
</row>
<row>
<entry><parameter>mbuf</parameter></entry>
<entry>New mbuf to be labeled</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Policy label to fill in for
<parameter>mbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on the mbuf header of a newly created
datagram generated using the passed BPF descriptor. This
call is made when a write is performed to the BPF device
associated with the passed BPF descriptor.</para>
</sect4>
<sect4 id="mac-mpo-create-mbuf-from-ifnet">
<title><function>&mac.mpo;_create_mbuf_from_ifnet</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mbuf_from_ifnet</function></funcdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>mbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>mbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label for
<parameter>ifnetlabel</parameter></entry>
</row>
<row>
<entry><parameter>mbuf</parameter></entry>
<entry>mbuf header for new datagram</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>mbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on the mbuf header of a newly created
datagram generated from the passed network interface.</para>
</sect4>
<sect4 id="mac-mpo-create-mbuf-multicast-encap">
<title><function>&mac.mpo;_create_mbuf_multicast_encap</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mbuf_multicast_encap</function></funcdef>
<paramdef>struct mbuf
*<parameter>oldmbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>oldmbuflabel</parameter></paramdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>newmbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>newmbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>oldmbuf</parameter></entry>
<entry>mbuf header for existing datagram</entry>
</row>
<row>
<entry><parameter>oldmbuflabel</parameter></entry>
<entry>Policy label for
<parameter>oldmbuf</parameter></entry>
</row>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label for
<parameter>ifnet</parameter></entry>
</row>
<row>
<entry><parameter>newmbuf</parameter></entry>
<entry>mbuf header to be labeled for new
datagram</entry>
</row>
<row>
<entry><parameter>newmbuflabel</parameter></entry>
<entry>Policy label to be filled in for
<parameter>newmbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on the mbuf header of a newly created
datagram generated from the existing passed datagram when it
is processed by the passed multicast encapsulation
interface. This call is made when an mbuf is to be
delivered using the virtual interface.</para>
</sect4>
<sect4 id="mac-mpo-create-mbuf-netlayer">
<title><function>&mac.mpo;_create_mbuf_netlayer</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_mbuf_netlayer</function></funcdef>
<paramdef>struct mbuf
*<parameter>oldmbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>oldmbuflabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>newmbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>newmbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>oldmbuf</parameter></entry>
<entry>Received datagram</entry>
</row>
<row>
<entry><parameter>oldmbuflabel</parameter></entry>
<entry>Policy label for
<parameter>oldmbuf</parameter></entry>
</row>
<row>
<entry><parameter>newmbuf</parameter></entry>
<entry>Newly created datagram</entry>
</row>
<row>
<entry><parameter>newmbuflabel</parameter></entry>
<entry>Policy label for
<parameter>newmbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label on the mbuf header of a newly created
datagram generated by the IP stack in response to an
existing received datagram (<parameter>oldmbuf</parameter>).
This call may be made in a number of situations, including
when responding to ICMP request datagrams.</para>
</sect4>
<sect4 id="mac-mpo-fragment-match">
<title><function>&mac.mpo;_fragment_match</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_fragment_match</function></funcdef>
<paramdef>struct mbuf
*<parameter>fragment</parameter></paramdef>
<paramdef>struct label
*<parameter>fragmentlabel</parameter></paramdef>
<paramdef>struct ipq
*<parameter>ipq</parameter></paramdef>
<paramdef>struct label
*<parameter>ipqlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>fragment</parameter></entry>
<entry>IP datagram fragment</entry>
</row>
<row>
<entry><parameter>fragmentlabel</parameter></entry>
<entry>Policy label for
<parameter>fragment</parameter></entry>
</row>
<row>
<entry><parameter>ipq</parameter></entry>
<entry>IP fragment reassembly queue</entry>
</row>
<row>
<entry><parameter>ipqlabel</parameter></entry>
<entry>Policy label for
<parameter>ipq</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether an mbuf header containing an IP
datagram (<parameter>fragment</parameter>) fragment matches
the label of the passed IP fragment reassembly queue
(<parameter>ipq</parameter>). Return
(<returnvalue>1</returnvalue>) for a successful match, or
(<returnvalue>0</returnvalue>) for no match. This call is
made when the IP stack attempts to find an existing fragment
reassembly queue for a newly received fragment; if this
fails, a new fragment reassembly queue may be instantiated
for the fragment. Policies may use this entry point to
prevent the reassembly of otherwise matching IP fragments if
policy does not permit them to be reassembled based on the
label or other information.</para>
</sect4>
<sect4 id="mac-mpo-ifnet-relabel">
<title><function>&mac.mpo;_relabel_ifnet</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_relabel_ifnet</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Object; Network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label for
<parameter>ifnet</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Label update to apply to
<parameter>ifnet</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Update the label of network interface,
<parameter>ifnet</parameter>, based on the passed update
label, <parameter>newlabel</parameter>, and the passed
subject credential, <parameter>cred</parameter>.</para>
</sect4>
<sect4 id="mac-mpo-update-ipq">
<title><function>&mac.mpo;_update_ipq</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_update_ipq</function></funcdef>
<paramdef>struct mbuf
*<parameter>fragment</parameter></paramdef>
<paramdef>struct label
*<parameter>fragmentlabel</parameter></paramdef>
<paramdef>struct ipq
*<parameter>ipq</parameter></paramdef>
<paramdef>struct label
*<parameter>ipqlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>mbuf</parameter></entry>
<entry>IP fragment</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Policy label for
<parameter>mbuf</parameter></entry>
</row>
<row>
<entry><parameter>ipq</parameter></entry>
<entry>IP fragment reassembly queue</entry>
</row>
<row>
<entry><parameter>ipqlabel</parameter></entry>
<entry>Policy label to be updated for
<parameter>ipq</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Update the label on an IP fragment reassembly queue
(<parameter>ipq</parameter>) based on the acceptance of the
passed IP fragment mbuf header
(<parameter>mbuf</parameter>).</para>
</sect4>
</sect3>
<sect3 id="mac-proc-labeling-event-ops">
<title>Process Labeling Event Operations</title>
<sect4 id="mac-mpo-create-cred">
<title><function>&mac.mpo;_create_cred</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_cred</function></funcdef>
<paramdef>struct ucred
*<parameter>parent_cred</parameter></paramdef>
<paramdef>struct ucred
*<parameter>child_cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>parent_cred</parameter></entry>
<entry>Parent subject credential</entry>
</row>
<row>
<entry><parameter>child_cred</parameter></entry>
<entry>Child subject credential</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Set the label of a newly created subject credential from
the passed subject credential. This call will be made when
&man.crcopy.9; is invoked on a newly created <type>struct
ucred</type>. This call should not be confused with a
process forking or creation event.</para>
</sect4>
<sect4 id="mac-mpo-execve-transition">
<title><function>&mac.mpo;_execve_transition</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_execve_transition</function></funcdef>
<paramdef>struct ucred
*<parameter>old</parameter></paramdef>
<paramdef>struct ucred
*<parameter>new</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vnodelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>old</parameter></entry>
<entry>Existing subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>new</parameter></entry>
<entry>New subject credential to be labeled</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>File to execute</entry>
<entry>Locked</entry>
</row>
<row>
<entry><parameter>vnodelabel</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Update the label of a newly created subject credential
(<parameter>new</parameter>) from the passed existing
subject credential (<parameter>old</parameter>) based on a
label transition caused by executing the passed vnode
(<parameter>vp</parameter>). This call occurs when a
process executes the passed vnode and one of the policies
returns a success from the
<function>mpo_execve_will_transition</function> entry point.
Policies may choose to implement this call simply by
invoking <function>mpo_create_cred</function> and passing
the two subject credentials so as not to implement a
transitioning event. Policies should not leave this entry
point unimplemented if they implement
<function>mpo_create_cred</function>, even if they do not
implement
<function>mpo_execve_will_transition</function>.</para>
</sect4>
<sect4 id="mac-mpo-execve-will-transition">
<title><function>&mac.mpo;_execve_will_transition</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_execve_will_transition</function></funcdef>
<paramdef>struct ucred
*<parameter>old</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vnodelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>old</parameter></entry>
<entry>Subject credential prior to
&man.execve.2;</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>File to execute</entry>
</row>
<row>
<entry><parameter>vnodelabel</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the policy will want to perform a
transition event as a result of the execution of the passed
vnode by the passed subject credential. Return
<returnvalue>1</returnvalue> if a transition is required,
<returnvalue>0</returnvalue> if not. Even if a policy
returns <returnvalue>0</returnvalue>, it should behave
correctly in the presence of an unexpected invocation of
<function>mpo_execve_transition</function>, as that call may
happen as a result of another policy requesting a
transition.</para>
</sect4>
<sect4 id="mac-mpo-create-proc0">
<title><function>&mac.mpo;_create_proc0</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_proc0</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential to be filled in</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Create the subject credential of process 0, the parent
of all kernel processes.</para>
</sect4>
<sect4 id="mac-mpo-create-proc1">
<title><function>&mac.mpo;_create_proc1</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_create_proc1</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential to be filled in</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Create the subject credential of process 1, the parent
of all user processes.</para>
</sect4>
<sect4 id="mac-mpo-relabel-cred">
<title><function>&mac.mpo;_relabel_cred</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_relabel_cred</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Label update to apply to
<parameter>cred</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Update the label on a subject credential from the passed
update label.</para>
</sect4>
</sect3>
</sect2>
<sect2 id="mac-access-control-checks">
<title>Access Control Checks</title>
<para>Access control entry points permit policy modules to
influence access control decisions made by the kernel.
Generally, although not always, arguments to an access control
entry point will include one or more authorizing credentials,
information (possibly including a label) for any other objects
involved in the operation. An access control entry point may
return 0 to permit the operation, or an &man.errno.2; error
value. The results of invoking the entry point across various
registered policy modules will be composed as follows: if all
modules permit the operation to succeed, success will be
returned. If one or modules returns a failure, a failure will
be returned. If more than one module returns a failure, the
errno value to return to the user will be selected using the
following precedence, implemented by the
<function>error_select()</function> function in
<filename>kern_mac.c</filename>:</para>
<informaltable>
<tgroup cols="2">
<tbody>
<row>
<entry>Most precedence</entry>
<entry><errorcode>EDEADLK</errorcode></entry></row>
<row>
<entry></entry>
<entry><errorcode>EINVAL</errorcode></entry>
</row>
<row>
<entry></entry>
<entry><errorcode>ESRCH</errorcode></entry>
</row>
<row>
<entry></entry>
<entry>EACCES</entry>
</row>
<row>
<entry>Least precedence</entry>
<entry>EPERM</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>If none of the error values returned by all modules are
listed in the precedence chart then an arbitrarily selected
value from the set will be returned. In general, the rules
provide precedence to errors in the following order: kernel
failures, invalid arguments, object not present, access not
permitted, other.</para>
<sect3 id="mac-mpo-bpfdesc-check-receive-from-ifnet">
<title><function>&mac.mpo;_check_bpfdesc_receive</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_bpfdesc_receive</function></funcdef>
<paramdef>struct bpf_d
*<parameter>bpf_d</parameter></paramdef>
<paramdef>struct label
*<parameter>bpflabel</parameter></paramdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>bpf_d</parameter></entry>
<entry>Subject; BPF descriptor</entry>
</row>
<row>
<entry><parameter>bpflabel</parameter></entry>
<entry>Policy label for
<parameter>bpf_d</parameter></entry>
</row>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Object; network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label for
<parameter>ifnet</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the MAC framework should permit
datagrams from the passed interface to be delivered to the
buffers of the passed BPF descriptor. Return
(<returnvalue>0</returnvalue>) for success, or an
<varname>errno</varname> value for failure Suggested
failure: <errorcode>EACCES</errorcode> for label mismatches,
<errorcode>EPERM</errorcode> for lack of privilege.</para>
</sect3>
<sect3 id="mac-mpo-check-kenv-dump">
<title><function>&mac.mpo;_check_kenv_dump</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_kenv_dump</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
retrieve the kernel environment (see &man.kenv.2;).</para>
</sect3>
<sect3 id="mac-mpo-check-kenv-get">
<title><function>&mac.mpo;_check_kenv_get</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_kenv_get</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>char *<parameter>name</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>name</parameter></entry>
<entry>Kernel environment variable name</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
retrieve the value of the specified kernel environment
variable.</para>
</sect3>
<sect3 id="mac-mpo-check-kenv-set">
<title><function>&mac.mpo;_check_kenv_set</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_kenv_set</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>char *<parameter>name</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>name</parameter></entry>
<entry>Kernel environment variable name</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to set
the specified kernel environment variable.</para>
</sect3>
<sect3 id="mac-mpo-check-kenv-unset">
<title><function>&mac.mpo;_check_kenv_unset</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_kenv_unset</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>char *<parameter>name</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>name</parameter></entry>
<entry>Kernel environment variable name</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to unset
the specified kernel environment variable.</para>
</sect3>
<sect3 id="mac-mpo-check-kld-load">
<title><function>&mac.mpo;_check_kld_load</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_kld_load</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Kernel module vnode</entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Label associated with
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to load
the specified module file.</para>
</sect3>
<sect3 id="mac-mpo-check-kld-stat">
<title><function>&mac.mpo;_check_kld_stat</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_kld_stat</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
retrieve a list of loaded kernel module files and associated
statistics.</para>
</sect3>
<sect3 id="mac-mpo-check-kld-unload">
<title><function>&mac.mpo;_check_kld_unload</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_kld_unload</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
unload a kernel module.</para>
</sect3>
<sect3 id="mac-mpo-check-pipe-ioctl">
<title><function>&mac.mpo;_check_pipe_ioctl</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_pipe_ioctl</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>pipelabel</parameter></paramdef>
<paramdef>unsigned long
<parameter>cmd</parameter></paramdef>
<paramdef>void *<parameter>data</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>pipelabel</parameter></entry>
<entry>Policy label associated with
<parameter>pipe</parameter></entry>
</row>
<row>
<entry><parameter>cmd</parameter></entry>
<entry>&man.ioctl.2; command</entry>
</row>
<row>
<entry><parameter>data</parameter></entry>
<entry>&man.ioctl.2; data</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to make
the specified &man.ioctl.2; call.</para>
</sect3>
<sect3 id="mac-mpo-check-pipe-poll">
<title><function>&mac.mpo;_check_pipe_poll</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_pipe_poll</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>pipelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>pipelabel</parameter></entry>
<entry>Policy label associated with
<parameter>pipe</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to poll
<parameter>pipe</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-pipe-read">
<title><function>&mac.mpo;_check_pipe_read</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_pipe_read</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>pipelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>pipelabel</parameter></entry>
<entry>Policy label associated with
<parameter>pipe</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed read
access to <parameter>pipe</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-pipe-relabel">
<title><function>&mac.mpo;_check_pipe_relabel</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_pipe_relabel</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>pipelabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>pipelabel</parameter></entry>
<entry>Current policy label associated with
<parameter>pipe</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Label update to
<parameter>pipelabel</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
relabel <parameter>pipe</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-pipe-stat">
<title><function>&mac.mpo;_check_pipe_stat</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_pipe_stat</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>pipelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>pipelabel</parameter></entry>
<entry>Policy label associated with
<parameter>pipe</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
retrieve statistics related to
<parameter>pipe</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-pipe-write">
<title><function>&mac.mpo;_check_pipe_write</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_pipe_write</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct pipe
*<parameter>pipe</parameter></paramdef>
<paramdef>struct label
*<parameter>pipelabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>pipe</parameter></entry>
<entry>Pipe</entry>
</row>
<row>
<entry><parameter>pipelabel</parameter></entry>
<entry>Policy label associated with
<parameter>pipe</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to write
to <parameter>pipe</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-socket-bind">
<title><function>&mac.mpo;_check_socket_bind</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_bind</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>socket</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
<paramdef>struct sockaddr
*<parameter>sockaddr</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>socket</parameter></entry>
<entry>Socket to be bound</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label for
<parameter>socket</parameter></entry>
</row>
<row>
<entry><parameter>sockaddr</parameter></entry>
<entry>Address of
<parameter>socket</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect3>
<sect3 id="mac-mpo-cred-check-socket-connect">
<title><function>&mac.mpo;_check_socket_connect</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_connect</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>socket</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
<paramdef>struct sockaddr
*<parameter>sockaddr</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>socket</parameter></entry>
<entry>Socket to be connected</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label for
<parameter>socket</parameter></entry>
</row>
<row>
<entry><parameter>sockaddr</parameter></entry>
<entry>Address of
<parameter>socket</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential
(<parameter>cred</parameter>) can connect the passed socket
(<parameter>socket</parameter>) to the passed socket address
(<parameter>sockaddr</parameter>). Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatches,
<errorcode>EPERM</errorcode> for lack of privilege.</para>
</sect3>
<sect3 id="mac-mpo-check-socket-receive">
<title><function>&mac.mpo;_check_socket_receive</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_receive</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>so</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>so</parameter></entry>
<entry>Socket</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label associated with
<parameter>so</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
receive information from the socket
<parameter>so</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-socket-send">
<title><function>&mac.mpo;_check_socket_send</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_send</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>so</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>so</parameter></entry>
<entry>Socket</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label associated with
<parameter>so</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to send
information across the socket
<parameter>so</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-cred-visible">
<title><function>&mac.mpo;_check_cred_visible</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_cred_visible</function></funcdef>
<paramdef>struct ucred
*<parameter>u1</parameter></paramdef>
<paramdef>struct ucred
*<parameter>u2</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>u1</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>u2</parameter></entry>
<entry>Object credential</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential
<parameter>u1</parameter> can <quote>see</quote> other
subjects with the passed subject credential
<parameter>u2</parameter>. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatches,
<errorcode>EPERM</errorcode> for lack of privilege, or
<errorcode>ESRCH</errorcode> to hide visibility. This call
may be made in a number of situations, including
inter-process status sysctls used by <command>ps</command>,
and in procfs lookups.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-socket-visible">
<title><function>&mac.mpo;_check_socket_visible</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_visible</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>socket</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>socket</parameter></entry>
<entry>Object; socket</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label for
<parameter>socket</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect3>
<sect3 id="mac-mpo-cred-check-ifnet-relabel">
<title><function>&mac.mpo;_check_ifnet_relabel</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_ifnet_relabel</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Object; network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Existing policy label for
<parameter>ifnet</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Policy label update to later be applied to
<parameter>ifnet</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can relabel the
passed network interface to the passed label update.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-socket-relabel">
<title><function>&mac.mpo;_check_socket_relabel</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_relabel</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>socket</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>socket</parameter></entry>
<entry>Object; socket</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Existing policy label for
<parameter>socket</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Label update to later be applied to
<parameter>socketlabel</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can relabel the
passed socket to the passed label update.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-cred-relabel">
<title><function>&mac.mpo;_check_cred_relabel</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_cred_relabel</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Label update to later be applied to
<parameter>cred</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can relabel
itself to the passed label update.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-relabel">
<title><function>&mac.mpo;_check_vnode_relabel</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_relabel</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vnodelabel</parameter></paramdef>
<paramdef>struct label
*<parameter>newlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
<entry>Locked</entry>
</row>
<row>
<entry><parameter>vnodelabel</parameter></entry>
<entry>Existing policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>newlabel</parameter></entry>
<entry>Policy label update to later be applied to
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can relabel the
passed vnode to the passed label update.</para>
</sect3>
<sect3 id="mpo-cred-check-mount-stat">
<title><function>&mac.mpo;_check_mount_stat</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>&mac.mpo;_check_mount_stat</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct mount
*<parameter>mp</parameter></paramdef>
<paramdef>struct label
*<parameter>mountlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>mp</parameter></entry>
<entry>Object; file system mount</entry>
</row>
<row>
<entry><parameter>mountlabel</parameter></entry>
<entry>Policy label for
<parameter>mp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<!-- XXX Update ? -->
<para>Determine whether the subject credential can see the
results of a statfs performed on the file system. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatches
or <errorcode>EPERM</errorcode> for lack of privilege. This
call may be made in a number of situations, including during
invocations of &man.statfs.2; and related calls, as well as to
determine what file systems to exclude from listings of file
systems, such as when &man.getfsstat.2; is invoked. </para>
</sect3>
<sect3 id="mac-mpo-cred-check-proc-debug">
<title><function>&mac.mpo;_check_proc_debug</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_proc_debug</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct proc
*<parameter>proc</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>proc</parameter></entry>
<entry>Object; process</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can debug the
passed process. Return <returnvalue>0</returnvalue> for
success, or an <varname>errno</varname> value for failure.
Suggested failure: <errorcode>EACCES</errorcode> for label
mismatch, <errorcode>EPERM</errorcode> for lack of
privilege, or <errorcode>ESRCH</errorcode> to hide
visibility of the target. This call may be made in a number
of situations, including use of the &man.ptrace.2; and
&man.ktrace.2; APIs, as well as for some types of procfs
operations.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-access">
<title><function>&mac.mpo;_check_vnode_access</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_access</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int <parameter>flags</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>flags</parameter></entry>
<entry>&man.access.2; flags</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine how invocations of &man.access.2; and related
calls by the subject credential should return when performed
on the passed vnode using the passed access flags. This
should generally be implemented using the same semantics
used in <function>&mac.mpo;_check_vnode_open</function>.
Return <returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatches
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-chdir">
<title><function>&mac.mpo;_check_vnode_chdir</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_chdir</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Object; vnode to &man.chdir.2; into</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label for
<parameter>dvp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can change the
process working directory to the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-chroot">
<title><function>&mac.mpo;_check_vnode_chroot</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_chroot</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Directory vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label associated with
<parameter>dvp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
&man.chroot.2; into the specified directory
(<parameter>dvp</parameter>).</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-create">
<title><function>&mac.mpo;_check_vnode_create</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_create</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
<paramdef>struct componentname
*<parameter>cnp</parameter></paramdef>
<paramdef>struct vattr
*<parameter>vap</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label for
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>cnp</parameter></entry>
<entry>Component name for
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>vap</parameter></entry>
<entry>vnode attributes for <parameter>vap</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can create a
vnode with the passed parent directory, passed name
information, and passed attribute information. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode>. for label mismatch,
or <errorcode>EPERM</errorcode> for lack of privilege.
This call may be made in a number of situations, including
as a result of calls to &man.open.2; with
<symbol>O_CREAT</symbol>, &man.mknod.2;, &man.mkfifo.2;, and
others.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-delete">
<title><function>&mac.mpo;_check_vnode_delete</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_delete</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>void *<parameter>label</parameter></paramdef>
<paramdef>struct componentname
*<parameter>cnp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Parent directory vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label for
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode to delete</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>cnp</parameter></entry>
<entry>Component name for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can delete a
vnode from the passed parent directory and passed name
information. Return <returnvalue>0</returnvalue> for
success, or an <varname>errno</varname> value for failure.
Suggested failure: <errorcode>EACCES</errorcode> for label
mismatch, or <errorcode>EPERM</errorcode> for lack of
privilege. This call may be made in a number of situations,
including as a result of calls to &man.unlink.2; and
&man.rmdir.2;. Policies implementing this entry point
should also implement
<function>mpo_check_rename_to</function> to authorize
deletion of objects as a result of being the target of a
rename.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-deleteacl">
<title><function>&mac.mpo;_check_vnode_deleteacl</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_deleteacl</function></funcdef>
<paramdef>struct ucred *<parameter>cred</parameter></paramdef>
<paramdef>struct vnode *<parameter>vp</parameter></paramdef>
<paramdef>struct label *<parameter>label</parameter></paramdef>
<paramdef>acl_type_t <parameter>type</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
<entry>Locked</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>type</parameter></entry>
<entry>ACL type</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can delete the
ACL of passed type from the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-exec">
<title><function>&mac.mpo;_check_vnode_exec</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_exec</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode to execute</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can execute the
passed vnode. Determination of execute privilege is made
separately from decisions about any transitioning event.
Return <returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mpo-cred-check-vnode-getacl">
<title><function>&mac.mpo;_check_vnode_getacl</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_getacl</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>acl_type_t
<parameter>type</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>type</parameter></entry>
<entry>ACL type</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can retrieve
the ACL of passed type from the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-getextattr">
<title><function>&mac.mpo;_check_vnode_getextattr</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_getextattr</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int
<parameter>attrnamespace</parameter></paramdef>
<paramdef>const char
*<parameter>name</parameter></paramdef>
<paramdef>struct uio
*<parameter>uio</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>attrnamespace</parameter></entry>
<entry>Extended attribute namespace</entry>
</row>
<row>
<entry><parameter>name</parameter></entry>
<entry>Extended attribute name</entry>
</row>
<row>
<entry><parameter>uio</parameter></entry>
<entry>I/O structure pointer; see &man.uio.9;</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can retrieve
the extended attribute with the passed namespace and name
from the passed vnode. Policies implementing labeling using
extended attributes may be interested in special handling of
operations on those extended attributes. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-link">
<title><function>&mac.mpo;_check_vnode_link</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_link</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>struct componentname
*<parameter>cnp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Directory vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label associated with
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Link destination vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>cnp</parameter></entry>
<entry>Component name for the link being created</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
create a link to the vnode <parameter>vp</parameter> with
the name specified by <parameter>cnp</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-mmap">
<title><function>&mac.mpo;_check_vnode_mmap</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_mmap</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int <parameter>prot</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Vnode to map</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>prot</parameter></entry>
<entry>Mmap protections (see &man.mmap.2;)</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to map
the vnode <parameter>vp</parameter> with the protections
specified in <parameter>prot</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-mmap-downgrade">
<title><function>&mac.mpo;_check_vnode_mmap_downgrade</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>void
<function>&mac.mpo;_check_vnode_mmap_downgrade</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int *<parameter>prot</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry morerows="2">See
<xref linkend="mac-mpo-check-vnode-mmap">.</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
</row>
<row>
<entry><parameter>prot</parameter></entry>
<entry>Mmap protections to be downgraded</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Downgrade the mmap protections based on the subject and
object labels.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-mprotect">
<title><function>&mac.mpo;_check_vnode_mprotect</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_mprotect</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int <parameter>prot</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Mapped vnode</entry>
</row>
<row>
<entry><parameter>prot</parameter></entry>
<entry>Memory protections</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
set the specified memory protections on memory mapped from
the vnode <parameter>vp</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-poll">
<title><function>&mac.mpo;_check_vnode_poll</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_poll</function></funcdef>
<paramdef>struct ucred
*<parameter>active_cred</parameter></paramdef>
<paramdef>struct ucred
*<parameter>file_cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>active_cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>file_cred</parameter></entry>
<entry>Credential associated with the <type>struct
file</type></entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Polled vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to poll
the vnode <parameter>vp</parameter>.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-rename-from">
<title><function>&mac.mpo;_check_vnode_rename_from</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_vnode_rename_from</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>struct componentname
*<parameter>cnp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Directory vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label associated with
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Vnode to be renamed</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>cnp</parameter></entry>
<entry>Component name for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
rename the vnode <parameter>vp</parameter> to something
else.</para>
</sect3>
<sect3 id="mac-mpo-check-vnode-rename-to">
<title><function>&mac.mpo;_check_vnode_rename_to</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_rename_to</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>dvp</parameter></paramdef>
<paramdef>struct label
*<parameter>dlabel</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int <parameter>samedir</parameter></paramdef>
<paramdef>struct componentname
*<parameter>cnp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Directory vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label associated with
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Overwritten vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label associated with
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>samedir</parameter></entry>
<entry>Boolean; <literal>1</literal> if the source and
destination directories are the same</entry>
</row>
<row>
<entry><parameter>cnp</parameter></entry>
<entry>Destination component name</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
rename to the vnode <parameter>vp</parameter>, into the
directory <parameter>dvp</parameter>, or to the name
represented by <parameter>cnp</parameter>. If there is no
existing file to overwrite, <parameter>vp</parameter> and
<parameter>label</parameter> will be NULL.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-socket-listen">
<title><function>&mac.mpo;_check_socket_listen</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_listen</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>socket</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>socket</parameter></entry>
<entry>Object; socket</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label for
<parameter>socket</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can listen on
the passed socket. Return <returnvalue>0</returnvalue> for
success, or an <varname>errno</varname> value for failure.
Suggested failure: <errorcode>EACCES</errorcode> for label
mismatch, or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-lookup">
<title><function>&mac.mpo;_check_vnode_lookup</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_lookup</function></funcdef>
<paramdef>struct ucred
*<parameter></parameter>cred</paramdef>
<paramdef>struct vnode
*<parameter></parameter>dvp</paramdef>
<paramdef>struct label
*<parameter></parameter>dlabel</paramdef>
<paramdef>struct componentname
*<parameter>cnp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label for
<parameter>dvp</parameter></entry>
</row>
<row>
<entry><parameter>cnp</parameter></entry>
<entry>Component name being looked up</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can perform a
lookup in the passed directory vnode for the passed name.
Return <returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-open">
<title><function>&mac.mpo;_check_vnode_open</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_open</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int
<parameter>acc_mode</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>acc_mode</parameter></entry>
<entry>&man.open.2; access mode</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can perform an
open operation on the passed vnode with the passed access
mode. Return <returnvalue>0</returnvalue> for success, or
an errno value for failure. Suggested failure:
<errorcode>EACCES</errorcode> for label mismatch, or
<errorcode>EPERM</errorcode> for lack of privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-readdir">
<title><function>&mac.mpo;_check_vnode_readdir</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_readdir</function></funcdef>
<paramdef>struct ucred
*<parameter></parameter>cred</paramdef>
<paramdef>struct vnode
*<parameter></parameter>dvp</paramdef>
<paramdef>struct label
*<parameter></parameter>dlabel</paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>dvp</parameter></entry>
<entry>Object; directory vnode</entry>
</row>
<row>
<entry><parameter>dlabel</parameter></entry>
<entry>Policy label for
<parameter>dvp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can perform a
<function>readdir</function> operation on the passed
directory vnode. Return <returnvalue>0</returnvalue> for
success, or an <varname>errno</varname> value for failure.
Suggested failure: <errorcode>EACCES</errorcode> for label
mismatch, or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-readlink">
<title><function>&mac.mpo;_check_vnode_readlink</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_readlink</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can perform a
<function>readlink</function> operation on the passed
symlink vnode. Return <returnvalue>0</returnvalue> for
success, or an <varname>errno</varname> value for failure.
Suggested failure: <errorcode>EACCES</errorcode> for label
mismatch, or <errorcode>EPERM</errorcode> for lack of
privilege. This call may be made in a number of situations,
including an explicit <function>readlink</function> call by
the user process, or as a result of an implicit
<function>readlink</function> during a name lookup by the
process.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-revoke">
<title><function>&mac.mpo;_check_vnode_revoke</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_revoke</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can revoke
access to the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-setacl">
<title><function>&mac.mpo;_check_vnode_setacl</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_setacl</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>acl_type_t
<parameter>type</parameter></paramdef>
<paramdef>struct acl
*<parameter>acl</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>type</parameter></entry>
<entry>ACL type</entry>
</row>
<row>
<entry><parameter>acl</parameter></entry>
<entry>ACL</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can set the
passed ACL of passed type on the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-setextattr">
<title><function>&mac.mpo;_check_vnode_setextattr</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_setextattr</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>int
<parameter>attrnamespace</parameter></paramdef>
<paramdef>const char
*<parameter>name</parameter></paramdef>
<paramdef>struct uio
*<parameter>uio</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for <parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>attrnamespace</parameter></entry>
<entry>Extended attribute namespace</entry>
</row>
<row>
<entry><parameter>name</parameter></entry>
<entry>Extended attribute name</entry>
</row>
<row>
<entry><parameter>uio</parameter></entry>
<entry>I/O structure pointer; see &man.uio.9;</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can set the
extended attribute of passed name and passed namespace on
the passed vnode. Policies implementing security labels
backed into extended attributes may want to provide
additional protections for those attributes. Additionally,
policies should avoid making decisions based on the data
referenced from <parameter>uio</parameter>, as there is a
potential race condition between this check and the actual
operation. The <parameter>uio</parameter> may also be
<literal>NULL</literal> if a delete operation is being
performed. Return <returnvalue>0</returnvalue> for success,
or an <varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-setflags">
<title><function>&mac.mpo;_check_vnode_setflags</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_setflags</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>u_long <parameter>flags</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>flags</parameter></entry>
<entry>File flags; see &man.chflags.2;</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can set the
passed flags on the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-setmode">
<title><function>&mac.mpo;_check_vnode_setmode</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_setmode</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>mode_t <parameter>mode</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for <parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>mode</parameter></entry>
<entry>File mode; see &man.chmod.2;</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can set the
passed mode on the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-setowner">
<title><function>&mac.mpo;_check_vnode_setowner</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_setowner</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
<paramdef>uid_t <parameter>uid</parameter></paramdef>
<paramdef>gid_t <parameter>gid</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for <parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>uid</parameter></entry>
<entry>User ID</entry>
</row>
<row>
<entry><parameter>gid</parameter></entry>
<entry>Group ID</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can set the
passed uid and passed gid as file uid and file gid on the
passed vnode. The IDs may be set to (<literal>-1</literal>)
to request no update. Return <returnvalue>0</returnvalue>
for success, or an <varname>errno</varname> value for
failure. Suggested failure: <errorcode>EACCES</errorcode>
for label mismatch, or <errorcode>EPERM</errorcode> for lack
of privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-setutimes">
<title><function>&mac.mpo;_check_vnode_setutimes</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_setutimes</function></funcdef>
<paramdef>struct ucred
*<parameter></parameter>cred</paramdef>
<paramdef>struct vnode
*<parameter></parameter>vp</paramdef>
<paramdef>struct label
*<parameter></parameter>label</paramdef>
<paramdef>struct timespec
<parameter></parameter>atime</paramdef>
<paramdef>struct timespec
<parameter></parameter>mtime</paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vp</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
<row>
<entry><parameter>atime</parameter></entry>
<entry>Access time; see &man.utimes.2;</entry>
</row>
<row>
<entry><parameter>mtime</parameter></entry>
<entry>Modification time; see &man.utimes.2;</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can set the
passed access timestamps on the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-proc-sched">
<title><function>&mac.mpo;_check_proc_sched</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_proc_sched</function></funcdef>
<paramdef>struct ucred
*<parameter>ucred</parameter></paramdef>
<paramdef>struct proc
*<parameter>proc</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>proc</parameter></entry>
<entry>Object; process</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can change the
scheduling parameters of the passed process. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
<errorcode>EPERM</errorcode> for lack of privilege, or
<errorcode>ESRCH</errorcode> to limit visibility.</para>
<para>See &man.setpriority.2; for more information.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-proc-signal">
<title><function>&mac.mpo;_check_proc_signal</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_proc_signal</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct proc
*<parameter>proc</parameter></paramdef>
<paramdef>int <parameter>signal</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>proc</parameter></entry>
<entry>Object; process</entry>
</row>
<row>
<entry><parameter>signal</parameter></entry>
<entry>Signal; see &man.kill.2;</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can deliver the
passed signal to the passed process. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
<errorcode>EPERM</errorcode> for lack of privilege, or
<errorcode>ESRCH</errorcode> to limit visibility.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-vnode-stat">
<title><function>&mac.mpo;_check_vnode_stat</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_vnode_stat</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>label</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Object; vnode</entry>
</row>
<row>
<entry><parameter>label</parameter></entry>
<entry>Policy label for
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential can
<function>stat</function> the passed vnode. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
<para>See &man.stat.2; for more information.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-ifnet-transmit">
<title><function>&mac.mpo;_check_ifnet_transmit</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_ifnet_transmit</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>mbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>mbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label for
<parameter>ifnet</parameter></entry>
</row>
<row>
<entry><parameter>mbuf</parameter></entry>
<entry>Object; mbuf to be sent</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Policy label for
<parameter>mbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the network interface can transmit the
passed mbuf. Return <returnvalue>0</returnvalue> for
success, or an <varname>errno</varname> value for failure.
Suggested failure: <errorcode>EACCES</errorcode> for label
mismatch, or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-cred-check-socket-deliver">
<title><function>&mac.mpo;_check_socket_deliver</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_deliver</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct ifnet
*<parameter>ifnet</parameter></paramdef>
<paramdef>struct label
*<parameter>ifnetlabel</parameter></paramdef>
<paramdef>struct mbuf
*<parameter>mbuf</parameter></paramdef>
<paramdef>struct label
*<parameter>mbuflabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>ifnet</parameter></entry>
<entry>Network interface</entry>
</row>
<row>
<entry><parameter>ifnetlabel</parameter></entry>
<entry>Policy label for
<parameter>ifnet</parameter></entry>
</row>
<row>
<entry><parameter>mbuf</parameter></entry>
<entry>Object; mbuf to be delivered</entry>
</row>
<row>
<entry><parameter>mbuflabel</parameter></entry>
<entry>Policy label for
<parameter>mbuf</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the socket may receive the datagram
stored in the passed mbuf header. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failures: <errorcode>EACCES</errorcode> for label mismatch,
or <errorcode>EPERM</errorcode> for lack of
privilege.</para>
</sect3>
<sect3 id="mac-mpo-check-socket-visible">
<title><function>&mac.mpo;_check_socket_visible</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_socket_visible</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct socket
*<parameter>so</parameter></paramdef>
<paramdef>struct label
*<parameter>socketlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
<entry>Immutable</entry>
</row>
<row>
<entry><parameter>so</parameter></entry>
<entry>Object; socket</entry>
</row>
<row>
<entry><parameter>socketlabel</parameter></entry>
<entry>Policy label for
<parameter>so</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject credential cred can "see"
the passed socket (<parameter>socket</parameter>) using
system monitoring functions, such as those employed by
&man.netstat.8; and &man.sockstat.1;. Return
<returnvalue>0</returnvalue> for success, or an
<varname>errno</varname> value for failure. Suggested
failure: <errorcode>EACCES</errorcode> for label mismatches,
<errorcode>EPERM</errorcode> for lack of privilege, or
<errorcode>ESRCH</errorcode> to hide visibility.</para>
</sect3>
<sect3 id="mac-mpo-check-system-acct">
<title><function>&mac.mpo;_check_system_acct</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_system_acct</function></funcdef>
<paramdef>struct ucred
*<parameter>ucred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>ucred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Accounting file; &man.acct.5;</entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Label associated with
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
enable accounting, based on its label and the label of the
accounting log file.</para>
</sect3>
<sect3 id="mac-mpo-check-system-nfsd">
<title><function>&mac.mpo;_check_system_nfsd</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_system_nfsd</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to call
&man.nfssvc.2;.</para>
</sect3>
<sect3 id="mac-mpo-check-system-reboot">
<title><function>&mac.mpo;_check_system_reboot</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_system_reboot</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>int <parameter>howto</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>howto</parameter></entry>
<entry><parameter>howto</parameter> parameter from
&man.reboot.2;</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to
reboot the system in the specified manner.</para>
</sect3>
<sect3 id="mac-mpo-check-system-settime">
<title><function>&mac.mpo;_check_system_settime</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_system_settime</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the user should be allowed to set the
system clock.</para>
</sect3>
<sect3 id="mac-mpo-check-system-swapon">
<title><function>&mac.mpo;_check_system_swapon</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_system_swapon</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>struct vnode
*<parameter>vp</parameter></paramdef>
<paramdef>struct label
*<parameter>vlabel</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>vp</parameter></entry>
<entry>Swap device</entry>
</row>
<row>
<entry><parameter>vlabel</parameter></entry>
<entry>Label associated with
<parameter>vp</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to add
<parameter>vp</parameter> as a swap device.</para>
</sect3>
<sect3 id="mac-mpo-check-system-sysctl">
<title><function>&mac.mpo;_check_system_sysctl</function></title>
<funcsynopsis>
<funcprototype>
<funcdef>int
<function>&mac.mpo;_check_system_sysctl</function></funcdef>
<paramdef>struct ucred
*<parameter>cred</parameter></paramdef>
<paramdef>int *<parameter>name</parameter></paramdef>
<paramdef>u_int *<parameter>namelen</parameter></paramdef>
<paramdef>void *<parameter>old</parameter></paramdef>
<paramdef>size_t
*<parameter>oldlenp</parameter></paramdef>
<paramdef>int <parameter>inkernel</parameter></paramdef>
<paramdef>void *<parameter>new</parameter></paramdef>
<paramdef>size_t <parameter>newlen</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<informaltable>
<tgroup cols="3">
&mac.thead;
<tbody>
<row>
<entry><parameter>cred</parameter></entry>
<entry>Subject credential</entry>
</row>
<row>
<entry><parameter>name</parameter></entry>
<entry morerows="3">See &man.sysctl.3;</entry>
</row>
<row>
<entry><parameter>namelen</parameter></entry>
</row>
<row>
<entry><parameter>old</parameter></entry>
</row>
<row>
<entry><parameter>oldlenp</parameter></entry>
</row>
<row>
<entry><parameter>inkernel</parameter></entry>
<entry>Boolean; <literal>1</literal> if called from
kernel</entry>
</row>
<row>
<entry><parameter>new</parameter></entry>
<entry morerows="1">See &man.sysctl.3;</entry>
</row>
<row>
<entry><parameter>newlen</parameter></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>Determine whether the subject should be allowed to make
the specified &man.sysctl.3; transaction.</para>
</sect3>
</sect2>
<sect2 id="mac-label-management">
<title>Label Management Calls</title>
<para>Relabel events occur when a user process has requested
that the label on an object be modified. A two-phase update
occurs: first, an access control check will be performed to
determine if the update is both valid and permitted, and then
the update itself is performed via a separate entry point.
Relabel entry points typically accept the object, object label
reference, and an update label submitted by the process.
Memory allocation during relabel is discouraged, as relabel
calls are not permitted to fail (failure should be reported
earlier in the relabel check).</para>
</sect2>
</sect1>
<sect1 id="mac-userland-arch">
<title>Userland Architecture</title>
<para>The TrustedBSD MAC Framework includes a number of
policy-agnostic elements, including MAC library interfaces
for abstractly managing labels, modifications to the system
credential management and login libraries to support the
assignment of MAC labels to users, and a set of tools to
monitor and modify labels on processes, files, and network
interfaces. More details on the user architecture will
be added to this section in the near future.</para>
<sect2 id="mac-userland-labels">
<title>APIs for Policy-Agnostic Label Management</title>
<para>The TrustedBSD MAC Framework provides a number of
library and system calls permitting applications to
manage MAC labels on objects using a policy-agnostic
interface. This permits applications to manipulate
labels for a variety of policies without being
written to support specific policies. These interfaces
are used by general-purpose tools such as &man.ifconfig.8;,
&man.ls.1; and &man.ps.1; to view labels on network
interfaces, files, and processes. The APIs also support
MAC management tools including &man.getfmac.8;,
&man.getpmac.8;, &man.setfmac.8;, &man.setfsmac.8;,
and &man.setpmac.8;. The MAC APIs are documented in
&man.mac.3;.</para>
<para>Applications handle MAC labels in two forms: an
internalized form used to return and set labels on
processes and objects (<literal>mac_t</literal>),
and externalized form based on C strings appropriate for
storage in configuration files, display to the user, or
input from the user. Each MAC label contains a number of
elements, each consisting of a name and value pair.
Policy modules in the kernel bind to specific names
and interpret the values in policy-specific ways. In
the externalized string form, labels are represented
by a comma-delimited list of name and value pairs separated
by the <literal>/</literal> character. Labels may be
directly converted to and from text using provided APIs;
when retrieving labels from the kernel, internalized
label storage must first be prepared for the desired
label element set. Typically, this is done in one of
two ways: using &man.mac.prepare.3; and an arbitrary
list of desired label elements, or one of the variants
of the call that loads a default element set from the
&man.mac.conf.5; configuration file. Per-object
defaults permit application writers to usefully display
labels associated with objects without being aware of
the policies present in the system.</para>
<note><para>Currently, direct manipulation of label elements
other than by conversion to a text string, string editing,
and conversion back to an internalized label is not supported
by the MAC library. Such interfaces may be added in the
future if they prove necessary for application
writers.</para></note>
</sect2>
<sect2 id="mac-userland-credentials">
<title>Binding of Labels to Users</title>
<para>The standard user context management interface,
&man.setusercontext.3;, has been modified to retrieve
MAC labels associated with a user's class from
&man.login.conf.5;. These labels are then set along
with other user context when either
<literal>LOGIN_SETALL</literal> is specified, or when
<literal>LOGIN_SETMAC</literal> is explicitly
specified.</para>
<note><para>It is expected that, in a future version of FreeBSD,
the MAC label database will be separated from the
<filename>login.conf</filename> user class abstraction,
and be maintained in a separate database. However, the
&man.setusercontext.3; API should remain the same
following such a change.</para></note>
</sect2>
</sect1>
<sect1 id="mac-conclusion">
<title>Conclusion</title>
<para>The TrustedBSD MAC framework permits kernel modules to
augment the system security policy in a highly integrated
manner. They may do this based on existing object properties,
or based on label data that is maintained with the assistance of
the MAC framework. The framework is sufficiently flexible to
implement a variety of policy types, including information flow
security policies such as MLS and Biba, as well as policies
based on existing BSD credentials or file protections. Policy
authors may wish to consult this documentation as well as
existing security modules when implementing a new security
service.</para>
</sect1>
</chapter>
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