xref: /freebsd/sys/security/mac/mac_framework.c (revision 18f67bc413e8a4e6b313c023e8612603f1ea17c0)
17bc82500SRobert Watson /*-
291ec0006SRobert Watson  * Copyright (c) 1999-2002, 2006, 2009 Robert N. M. Watson
37bc82500SRobert Watson  * Copyright (c) 2001 Ilmar S. Habibulin
4f0c2044bSRobert Watson  * Copyright (c) 2001-2005 Networks Associates Technology, Inc.
5aed55708SRobert Watson  * Copyright (c) 2005-2006 SPARTA, Inc.
69162f64bSRobert Watson  * Copyright (c) 2008-2009 Apple Inc.
77bc82500SRobert Watson  * All rights reserved.
87bc82500SRobert Watson  *
97bc82500SRobert Watson  * This software was developed by Robert Watson and Ilmar Habibulin for the
107bc82500SRobert Watson  * TrustedBSD Project.
117bc82500SRobert Watson  *
126201265bSRobert Watson  * This software was developed for the FreeBSD Project in part by Network
136201265bSRobert Watson  * Associates Laboratories, the Security Research Division of Network
146201265bSRobert Watson  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
156201265bSRobert Watson  * as part of the DARPA CHATS research program.
167bc82500SRobert Watson  *
1749bb6870SRobert Watson  * This software was enhanced by SPARTA ISSO under SPAWAR contract
1849bb6870SRobert Watson  * N66001-04-C-6019 ("SEFOS").
1949bb6870SRobert Watson  *
206f6174a7SRobert Watson  * This software was developed at the University of Cambridge Computer
216f6174a7SRobert Watson  * Laboratory with support from a grant from Google, Inc.
226f6174a7SRobert Watson  *
237bc82500SRobert Watson  * Redistribution and use in source and binary forms, with or without
247bc82500SRobert Watson  * modification, are permitted provided that the following conditions
257bc82500SRobert Watson  * are met:
267bc82500SRobert Watson  * 1. Redistributions of source code must retain the above copyright
277bc82500SRobert Watson  *    notice, this list of conditions and the following disclaimer.
287bc82500SRobert Watson  * 2. Redistributions in binary form must reproduce the above copyright
297bc82500SRobert Watson  *    notice, this list of conditions and the following disclaimer in the
307bc82500SRobert Watson  *    documentation and/or other materials provided with the distribution.
317bc82500SRobert Watson  *
327bc82500SRobert Watson  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
337bc82500SRobert Watson  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
347bc82500SRobert Watson  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
357bc82500SRobert Watson  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
367bc82500SRobert Watson  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
377bc82500SRobert Watson  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
387bc82500SRobert Watson  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
397bc82500SRobert Watson  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
407bc82500SRobert Watson  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
417bc82500SRobert Watson  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
427bc82500SRobert Watson  * SUCH DAMAGE.
437bc82500SRobert Watson  */
44677b542eSDavid E. O'Brien 
45c8e7bf92SRobert Watson /*-
46471e5756SRobert Watson  * Framework for extensible kernel access control.  This file contains core
47471e5756SRobert Watson  * kernel infrastructure for the TrustedBSD MAC Framework, including policy
48471e5756SRobert Watson  * registration, versioning, locking, error composition operator, and system
49471e5756SRobert Watson  * calls.
50471e5756SRobert Watson  *
51471e5756SRobert Watson  * The MAC Framework implements three programming interfaces:
52471e5756SRobert Watson  *
53471e5756SRobert Watson  * - The kernel MAC interface, defined in mac_framework.h, and invoked
54471e5756SRobert Watson  *   throughout the kernel to request security decisions, notify of security
55471e5756SRobert Watson  *   related events, etc.
56471e5756SRobert Watson  *
57471e5756SRobert Watson  * - The MAC policy module interface, defined in mac_policy.h, which is
58471e5756SRobert Watson  *   implemented by MAC policy modules and invoked by the MAC Framework to
59471e5756SRobert Watson  *   forward kernel security requests and notifications to policy modules.
60471e5756SRobert Watson  *
61471e5756SRobert Watson  * - The user MAC API, defined in mac.h, which allows user programs to query
62471e5756SRobert Watson  *   and set label state on objects.
63471e5756SRobert Watson  *
64471e5756SRobert Watson  * The majority of the MAC Framework implementation may be found in
65471e5756SRobert Watson  * src/sys/security/mac.  Sample policy modules may be found in
6649869305STom Rhodes  * src/sys/security/mac_*.
677bc82500SRobert Watson  */
687bc82500SRobert Watson 
6939b73a30SRobert Watson #include "opt_mac.h"
7039b73a30SRobert Watson 
71677b542eSDavid E. O'Brien #include <sys/cdefs.h>
72677b542eSDavid E. O'Brien __FBSDID("$FreeBSD$");
73677b542eSDavid E. O'Brien 
747bc82500SRobert Watson #include <sys/param.h>
757a7ce668SAndriy Gapon #include <sys/systm.h>
76a96acd1aSRobert Watson #include <sys/condvar.h>
7795fab37eSRobert Watson #include <sys/kernel.h>
7895fab37eSRobert Watson #include <sys/lock.h>
7995fab37eSRobert Watson #include <sys/mac.h>
807ba28492SRobert Watson #include <sys/module.h>
8181fee06fSRobert Watson #include <sys/rmlock.h>
8291ec0006SRobert Watson #include <sys/sdt.h>
8340202729SRobert Watson #include <sys/sx.h>
8495fab37eSRobert Watson #include <sys/sysctl.h>
8595fab37eSRobert Watson 
86aed55708SRobert Watson #include <security/mac/mac_framework.h>
876fa0475dSRobert Watson #include <security/mac/mac_internal.h>
880efd6615SRobert Watson #include <security/mac/mac_policy.h>
896fa0475dSRobert Watson 
907ba28492SRobert Watson /*
912087a58cSRobert Watson  * DTrace SDT providers for MAC.
9291ec0006SRobert Watson  */
9391ec0006SRobert Watson SDT_PROVIDER_DEFINE(mac);
942087a58cSRobert Watson SDT_PROVIDER_DEFINE(mac_framework);
952087a58cSRobert Watson 
9636160958SMark Johnston SDT_PROBE_DEFINE2(mac, , policy, modevent, "int",
9792c6196cSMark Johnston     "struct mac_policy_conf *");
9836160958SMark Johnston SDT_PROBE_DEFINE1(mac, , policy, register,
9979856499SRui Paulo     "struct mac_policy_conf *");
10036160958SMark Johnston SDT_PROBE_DEFINE1(mac, , policy, unregister,
10179856499SRui Paulo     "struct mac_policy_conf *");
10291ec0006SRobert Watson 
10391ec0006SRobert Watson /*
104471e5756SRobert Watson  * Root sysctl node for all MAC and MAC policy controls.
1057ba28492SRobert Watson  */
1067029da5cSPawel Biernacki SYSCTL_NODE(_security, OID_AUTO, mac, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
10795fab37eSRobert Watson     "TrustedBSD MAC policy controls");
108b2f0927aSRobert Watson 
10917041e67SRobert Watson /*
110471e5756SRobert Watson  * Declare that the kernel provides MAC support, version 3 (FreeBSD 7.x).
111471e5756SRobert Watson  * This permits modules to refuse to be loaded if the necessary support isn't
112471e5756SRobert Watson  * present, even if it's pre-boot.
113471e5756SRobert Watson  */
114471e5756SRobert Watson MODULE_VERSION(kernel_mac_support, MAC_VERSION);
115be23ba9aSRobert Watson 
116be23ba9aSRobert Watson static unsigned int	mac_version = MAC_VERSION;
117471e5756SRobert Watson SYSCTL_UINT(_security_mac, OID_AUTO, version, CTLFLAG_RD, &mac_version, 0,
118471e5756SRobert Watson     "");
119471e5756SRobert Watson 
120471e5756SRobert Watson /*
1213ea3fbe6SMateusz Guzik  * Flags for inlined checks. Note this would be best hotpatched at runtime.
1223ea3fbe6SMateusz Guzik  * The following is a band-aid.
1233ea3fbe6SMateusz Guzik  *
1243ea3fbe6SMateusz Guzik  * Use FPFLAG for hooks running in commonly executed paths and FPFLAG_RARE
1253ea3fbe6SMateusz Guzik  * for the rest.
12691061084SMateusz Guzik  */
12791061084SMateusz Guzik #define FPFLAG(f)	\
12891061084SMateusz Guzik bool __read_frequently mac_##f##_fp_flag
12991061084SMateusz Guzik 
1303ea3fbe6SMateusz Guzik #define FPFLAG_RARE(f)	\
1313ea3fbe6SMateusz Guzik bool __read_mostly mac_##f##_fp_flag
1323ea3fbe6SMateusz Guzik 
13391061084SMateusz Guzik FPFLAG(priv_check);
13491061084SMateusz Guzik FPFLAG(priv_grant);
1356ebab6baSMateusz Guzik FPFLAG(vnode_check_lookup);
1366ebab6baSMateusz Guzik FPFLAG(vnode_check_open);
1376ebab6baSMateusz Guzik FPFLAG(vnode_check_stat);
1386ebab6baSMateusz Guzik FPFLAG(vnode_check_read);
1396ebab6baSMateusz Guzik FPFLAG(vnode_check_write);
1406ebab6baSMateusz Guzik FPFLAG(vnode_check_mmap);
1413ea3fbe6SMateusz Guzik FPFLAG_RARE(vnode_check_poll);
142fad6dd77SMateusz Guzik FPFLAG_RARE(vnode_check_rename_from);
143*18f67bc4SMateusz Guzik FPFLAG_RARE(vnode_check_access);
14491061084SMateusz Guzik 
14591061084SMateusz Guzik #undef FPFLAG
1463ea3fbe6SMateusz Guzik #undef FPFLAG_RARE
14791061084SMateusz Guzik 
14891061084SMateusz Guzik /*
14917041e67SRobert Watson  * Labels consist of a indexed set of "slots", which are allocated policies
15017041e67SRobert Watson  * as required.  The MAC Framework maintains a bitmask of slots allocated so
15117041e67SRobert Watson  * far to prevent reuse.  Slots cannot be reused, as the MAC Framework
15217041e67SRobert Watson  * guarantees that newly allocated slots in labels will be NULL unless
15317041e67SRobert Watson  * otherwise initialized, and because we do not have a mechanism to garbage
15417041e67SRobert Watson  * collect slots on policy unload.  As labeled policies tend to be statically
15517041e67SRobert Watson  * loaded during boot, and not frequently unloaded and reloaded, this is not
15617041e67SRobert Watson  * generally an issue.
15717041e67SRobert Watson  */
158b2aef571SRobert Watson #if MAC_MAX_SLOTS > 32
159b2aef571SRobert Watson #error "MAC_MAX_SLOTS too large"
16095fab37eSRobert Watson #endif
161a13c67daSRobert Watson 
162b2aef571SRobert Watson static unsigned int mac_max_slots = MAC_MAX_SLOTS;
163b2aef571SRobert Watson static unsigned int mac_slot_offsets_free = (1 << MAC_MAX_SLOTS) - 1;
164471e5756SRobert Watson SYSCTL_UINT(_security_mac, OID_AUTO, max_slots, CTLFLAG_RD, &mac_max_slots,
165471e5756SRobert Watson     0, "");
16695fab37eSRobert Watson 
167a67fe518SRobert Watson /*
168a67fe518SRobert Watson  * Has the kernel started generating labeled objects yet?  All read/write
169a67fe518SRobert Watson  * access to this variable is serialized during the boot process.  Following
170a67fe518SRobert Watson  * the end of serialization, we don't update this flag; no locking.
171a67fe518SRobert Watson  */
172be23ba9aSRobert Watson static int	mac_late = 0;
173763bbd2fSRobert Watson 
174225bff6fSRobert Watson /*
1756356dba0SRobert Watson  * Each policy declares a mask of object types requiring labels to be
1766356dba0SRobert Watson  * allocated for them.  For convenience, we combine and cache the bitwise or
1776356dba0SRobert Watson  * of the per-policy object flags to track whether we will allocate a label
1786356dba0SRobert Watson  * for an object type at run-time.
179225bff6fSRobert Watson  */
1806356dba0SRobert Watson uint64_t	mac_labeled;
181123d2cb7SMatthew D Fleming SYSCTL_UQUAD(_security_mac, OID_AUTO, labeled, CTLFLAG_RD, &mac_labeled, 0,
1826356dba0SRobert Watson     "Mask of object types being labeled");
183225bff6fSRobert Watson 
184f7b951a8SRobert Watson MALLOC_DEFINE(M_MACTEMP, "mactemp", "MAC temporary label storage");
18595fab37eSRobert Watson 
18695fab37eSRobert Watson /*
18740202729SRobert Watson  * MAC policy modules are placed in one of two lists: mac_static_policy_list,
18840202729SRobert Watson  * for policies that are loaded early and cannot be unloaded, and
18940202729SRobert Watson  * mac_policy_list, which holds policies either loaded later in the boot
19040202729SRobert Watson  * cycle or that may be unloaded.  The static policy list does not require
19140202729SRobert Watson  * locks to iterate over, but the dynamic list requires synchronization.
19240202729SRobert Watson  * Support for dynamic policy loading can be compiled out using the
19340202729SRobert Watson  * MAC_STATIC kernel option.
19441a17fe3SRobert Watson  *
19540202729SRobert Watson  * The dynamic policy list is protected by two locks: modifying the list
19640202729SRobert Watson  * requires both locks to be held exclusively.  One of the locks,
19781fee06fSRobert Watson  * mac_policy_rm, is acquired over policy entry points that will never sleep;
198407a5b79SJason A. Harmening  * the other, mac_policy_rms, is acquired over policy entry points that may
19940202729SRobert Watson  * sleep.  The former category will be used when kernel locks may be held
20040202729SRobert Watson  * over calls to the MAC Framework, during network processing in ithreads,
20140202729SRobert Watson  * etc.  The latter will tend to involve potentially blocking memory
20240202729SRobert Watson  * allocations, extended attribute I/O, etc.
20395fab37eSRobert Watson  */
2040a05006dSRobert Watson #ifndef MAC_STATIC
20581fee06fSRobert Watson static struct rmlock mac_policy_rm;	/* Non-sleeping entry points. */
206407a5b79SJason A. Harmening static struct rmslock mac_policy_rms;	/* Sleeping entry points. */
2070a05006dSRobert Watson #endif
20840202729SRobert Watson 
209089c1bdaSRobert Watson struct mac_policy_list_head mac_policy_list;
210089c1bdaSRobert Watson struct mac_policy_list_head mac_static_policy_list;
211f93bfb23SRobert Watson u_int mac_policy_count;			/* Registered policy count. */
212a96acd1aSRobert Watson 
21340202729SRobert Watson static void	mac_policy_xlock(void);
21440202729SRobert Watson static void	mac_policy_xlock_assert(void);
21540202729SRobert Watson static void	mac_policy_xunlock(void);
21640202729SRobert Watson 
217089c1bdaSRobert Watson void
21881fee06fSRobert Watson mac_policy_slock_nosleep(struct rm_priotracker *tracker)
21941a17fe3SRobert Watson {
220c8e7bf92SRobert Watson 
2210a05006dSRobert Watson #ifndef MAC_STATIC
2221e4cadcbSRobert Watson 	if (!mac_late)
2231e4cadcbSRobert Watson 		return;
2241e4cadcbSRobert Watson 
22581fee06fSRobert Watson 	rm_rlock(&mac_policy_rm, tracker);
22640202729SRobert Watson #endif
22740202729SRobert Watson }
22840202729SRobert Watson 
22940202729SRobert Watson void
23040202729SRobert Watson mac_policy_slock_sleep(void)
23140202729SRobert Watson {
23240202729SRobert Watson 
23341a17fe3SRobert Watson 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
23440202729SRobert Watson  	    "mac_policy_slock_sleep");
23540202729SRobert Watson 
23640202729SRobert Watson #ifndef MAC_STATIC
23740202729SRobert Watson 	if (!mac_late)
23840202729SRobert Watson 		return;
23940202729SRobert Watson 
240deb2e577SMateusz Guzik 	rms_rlock(&mac_policy_rms);
2410a05006dSRobert Watson #endif
24241a17fe3SRobert Watson }
24395fab37eSRobert Watson 
244089c1bdaSRobert Watson void
24581fee06fSRobert Watson mac_policy_sunlock_nosleep(struct rm_priotracker *tracker)
24641a17fe3SRobert Watson {
247c8e7bf92SRobert Watson 
2480a05006dSRobert Watson #ifndef MAC_STATIC
2491e4cadcbSRobert Watson 	if (!mac_late)
2501e4cadcbSRobert Watson 		return;
2511e4cadcbSRobert Watson 
25281fee06fSRobert Watson 	rm_runlock(&mac_policy_rm, tracker);
2530a05006dSRobert Watson #endif
25441a17fe3SRobert Watson }
255225bff6fSRobert Watson 
256089c1bdaSRobert Watson void
25740202729SRobert Watson mac_policy_sunlock_sleep(void)
25841a17fe3SRobert Watson {
259c8e7bf92SRobert Watson 
2600a05006dSRobert Watson #ifndef MAC_STATIC
2611e4cadcbSRobert Watson 	if (!mac_late)
2621e4cadcbSRobert Watson 		return;
2631e4cadcbSRobert Watson 
264deb2e577SMateusz Guzik 	rms_runlock(&mac_policy_rms);
2650a05006dSRobert Watson #endif
26641a17fe3SRobert Watson }
26741a17fe3SRobert Watson 
26840202729SRobert Watson static void
26940202729SRobert Watson mac_policy_xlock(void)
27041a17fe3SRobert Watson {
27140202729SRobert Watson 
27240202729SRobert Watson 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
27340202729SRobert Watson  	    "mac_policy_xlock()");
27440202729SRobert Watson 
2750a05006dSRobert Watson #ifndef MAC_STATIC
2761e4cadcbSRobert Watson 	if (!mac_late)
2771e4cadcbSRobert Watson 		return;
2781e4cadcbSRobert Watson 
279deb2e577SMateusz Guzik 	rms_wlock(&mac_policy_rms);
28081fee06fSRobert Watson 	rm_wlock(&mac_policy_rm);
28140202729SRobert Watson #endif
28240202729SRobert Watson }
283989d4098SRobert Watson 
28440202729SRobert Watson static void
28540202729SRobert Watson mac_policy_xunlock(void)
28640202729SRobert Watson {
28740202729SRobert Watson 
28840202729SRobert Watson #ifndef MAC_STATIC
28940202729SRobert Watson 	if (!mac_late)
29040202729SRobert Watson 		return;
29140202729SRobert Watson 
29281fee06fSRobert Watson 	rm_wunlock(&mac_policy_rm);
293deb2e577SMateusz Guzik 	rms_wunlock(&mac_policy_rms);
29440202729SRobert Watson #endif
29540202729SRobert Watson }
29640202729SRobert Watson 
29740202729SRobert Watson static void
29840202729SRobert Watson mac_policy_xlock_assert(void)
29940202729SRobert Watson {
30040202729SRobert Watson 
30140202729SRobert Watson #ifndef MAC_STATIC
30240202729SRobert Watson 	if (!mac_late)
30340202729SRobert Watson 		return;
30440202729SRobert Watson 
305407a5b79SJason A. Harmening 	rm_assert(&mac_policy_rm, RA_WLOCKED);
3060a05006dSRobert Watson #endif
30741a17fe3SRobert Watson }
30895fab37eSRobert Watson 
30995fab37eSRobert Watson /*
31095fab37eSRobert Watson  * Initialize the MAC subsystem, including appropriate SMP locks.
31195fab37eSRobert Watson  */
31295fab37eSRobert Watson static void
31395fab37eSRobert Watson mac_init(void)
31495fab37eSRobert Watson {
31595fab37eSRobert Watson 
31641a17fe3SRobert Watson 	LIST_INIT(&mac_static_policy_list);
31795fab37eSRobert Watson 	LIST_INIT(&mac_policy_list);
318eca8a663SRobert Watson 	mac_labelzone_init();
31941a17fe3SRobert Watson 
3200a05006dSRobert Watson #ifndef MAC_STATIC
321f7fadf1fSKonstantin Belousov 	rm_init_flags(&mac_policy_rm, "mac_policy_rm", RM_NOWITNESS |
322f7fadf1fSKonstantin Belousov 	    RM_RECURSE);
323deb2e577SMateusz Guzik 	rms_init(&mac_policy_rms, "mac_policy_rms");
3240a05006dSRobert Watson #endif
32595fab37eSRobert Watson }
32695fab37eSRobert Watson 
32795fab37eSRobert Watson /*
32817041e67SRobert Watson  * For the purposes of modules that want to know if they were loaded "early",
32917041e67SRobert Watson  * set the mac_late flag once we've processed modules either linked into the
33017041e67SRobert Watson  * kernel, or loaded before the kernel startup.
33195fab37eSRobert Watson  */
33295fab37eSRobert Watson static void
33395fab37eSRobert Watson mac_late_init(void)
33495fab37eSRobert Watson {
33595fab37eSRobert Watson 
33695fab37eSRobert Watson 	mac_late = 1;
33795fab37eSRobert Watson }
33895fab37eSRobert Watson 
33995fab37eSRobert Watson /*
3409162f64bSRobert Watson  * Given a policy, derive from its set of non-NULL label init methods what
3419162f64bSRobert Watson  * object types the policy is interested in.
3429162f64bSRobert Watson  */
3439162f64bSRobert Watson static uint64_t
3449162f64bSRobert Watson mac_policy_getlabeled(struct mac_policy_conf *mpc)
3459162f64bSRobert Watson {
3469162f64bSRobert Watson 	uint64_t labeled;
3479162f64bSRobert Watson 
3489162f64bSRobert Watson #define	MPC_FLAG(method, flag)					\
3499162f64bSRobert Watson 	if (mpc->mpc_ops->mpo_ ## method != NULL)			\
3509162f64bSRobert Watson 		labeled |= (flag);					\
3519162f64bSRobert Watson 
3529162f64bSRobert Watson 	labeled = 0;
3539162f64bSRobert Watson 	MPC_FLAG(cred_init_label, MPC_OBJECT_CRED);
3549162f64bSRobert Watson 	MPC_FLAG(proc_init_label, MPC_OBJECT_PROC);
3559162f64bSRobert Watson 	MPC_FLAG(vnode_init_label, MPC_OBJECT_VNODE);
3569162f64bSRobert Watson 	MPC_FLAG(inpcb_init_label, MPC_OBJECT_INPCB);
3579162f64bSRobert Watson 	MPC_FLAG(socket_init_label, MPC_OBJECT_SOCKET);
3589162f64bSRobert Watson 	MPC_FLAG(devfs_init_label, MPC_OBJECT_DEVFS);
3599162f64bSRobert Watson 	MPC_FLAG(mbuf_init_label, MPC_OBJECT_MBUF);
3609162f64bSRobert Watson 	MPC_FLAG(ipq_init_label, MPC_OBJECT_IPQ);
3619162f64bSRobert Watson 	MPC_FLAG(ifnet_init_label, MPC_OBJECT_IFNET);
3629162f64bSRobert Watson 	MPC_FLAG(bpfdesc_init_label, MPC_OBJECT_BPFDESC);
3639162f64bSRobert Watson 	MPC_FLAG(pipe_init_label, MPC_OBJECT_PIPE);
3649162f64bSRobert Watson 	MPC_FLAG(mount_init_label, MPC_OBJECT_MOUNT);
3659162f64bSRobert Watson 	MPC_FLAG(posixsem_init_label, MPC_OBJECT_POSIXSEM);
3669162f64bSRobert Watson 	MPC_FLAG(posixshm_init_label, MPC_OBJECT_POSIXSHM);
3679162f64bSRobert Watson 	MPC_FLAG(sysvmsg_init_label, MPC_OBJECT_SYSVMSG);
3689162f64bSRobert Watson 	MPC_FLAG(sysvmsq_init_label, MPC_OBJECT_SYSVMSQ);
3699162f64bSRobert Watson 	MPC_FLAG(sysvsem_init_label, MPC_OBJECT_SYSVSEM);
3709162f64bSRobert Watson 	MPC_FLAG(sysvshm_init_label, MPC_OBJECT_SYSVSHM);
3719162f64bSRobert Watson 	MPC_FLAG(syncache_init_label, MPC_OBJECT_SYNCACHE);
3729162f64bSRobert Watson 	MPC_FLAG(ip6q_init_label, MPC_OBJECT_IP6Q);
3739162f64bSRobert Watson 
3749162f64bSRobert Watson #undef MPC_FLAG
3759162f64bSRobert Watson 	return (labeled);
3769162f64bSRobert Watson }
3779162f64bSRobert Watson 
3789162f64bSRobert Watson /*
3799162f64bSRobert Watson  * When policies are loaded or unloaded, walk the list of registered policies
3809162f64bSRobert Watson  * and built mac_labeled, a bitmask representing the union of all objects
3819162f64bSRobert Watson  * requiring labels across all policies.
382225bff6fSRobert Watson  */
383225bff6fSRobert Watson static void
384f93bfb23SRobert Watson mac_policy_update(void)
385225bff6fSRobert Watson {
3866356dba0SRobert Watson 	struct mac_policy_conf *mpc;
387225bff6fSRobert Watson 
38840202729SRobert Watson 	mac_policy_xlock_assert();
389225bff6fSRobert Watson 
3906356dba0SRobert Watson 	mac_labeled = 0;
391f93bfb23SRobert Watson 	mac_policy_count = 0;
392f93bfb23SRobert Watson 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {
3939162f64bSRobert Watson 		mac_labeled |= mac_policy_getlabeled(mpc);
394f93bfb23SRobert Watson 		mac_policy_count++;
395f93bfb23SRobert Watson 	}
396f93bfb23SRobert Watson 	LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {
3979162f64bSRobert Watson 		mac_labeled |= mac_policy_getlabeled(mpc);
398f93bfb23SRobert Watson 		mac_policy_count++;
399f93bfb23SRobert Watson 	}
400225bff6fSRobert Watson }
401225bff6fSRobert Watson 
40291061084SMateusz Guzik /*
40391061084SMateusz Guzik  * There are frequently used code paths which check for rarely installed
40491061084SMateusz Guzik  * policies. Gross hack below enables doing it in a cheap manner.
40591061084SMateusz Guzik  */
40691061084SMateusz Guzik 
40791061084SMateusz Guzik #define FPO(f)	(offsetof(struct mac_policy_ops, mpo_##f) / sizeof(uintptr_t))
40891061084SMateusz Guzik 
40991061084SMateusz Guzik struct mac_policy_fastpath_elem {
41091061084SMateusz Guzik 	int	count;
41191061084SMateusz Guzik 	bool	*flag;
41291061084SMateusz Guzik 	size_t	offset;
41391061084SMateusz Guzik };
41491061084SMateusz Guzik 
41591061084SMateusz Guzik struct mac_policy_fastpath_elem mac_policy_fastpath_array[] = {
41691061084SMateusz Guzik 	{ .offset = FPO(priv_check), .flag = &mac_priv_check_fp_flag },
41791061084SMateusz Guzik 	{ .offset = FPO(priv_grant), .flag = &mac_priv_grant_fp_flag },
4186ebab6baSMateusz Guzik 	{ .offset = FPO(vnode_check_lookup),
4196ebab6baSMateusz Guzik 		.flag = &mac_vnode_check_lookup_fp_flag },
4206ebab6baSMateusz Guzik 	{ .offset = FPO(vnode_check_open),
4216ebab6baSMateusz Guzik 		.flag = &mac_vnode_check_open_fp_flag },
4226ebab6baSMateusz Guzik 	{ .offset = FPO(vnode_check_stat),
4236ebab6baSMateusz Guzik 		.flag = &mac_vnode_check_stat_fp_flag },
4246ebab6baSMateusz Guzik 	{ .offset = FPO(vnode_check_read),
4256ebab6baSMateusz Guzik 		.flag = &mac_vnode_check_read_fp_flag },
4266ebab6baSMateusz Guzik 	{ .offset = FPO(vnode_check_write),
4276ebab6baSMateusz Guzik 		.flag = &mac_vnode_check_write_fp_flag },
4286ebab6baSMateusz Guzik 	{ .offset = FPO(vnode_check_mmap),
4296ebab6baSMateusz Guzik 		.flag = &mac_vnode_check_mmap_fp_flag },
4303ea3fbe6SMateusz Guzik 	{ .offset = FPO(vnode_check_poll),
4313ea3fbe6SMateusz Guzik 		.flag = &mac_vnode_check_poll_fp_flag },
432fad6dd77SMateusz Guzik 	{ .offset = FPO(vnode_check_rename_from),
433fad6dd77SMateusz Guzik 		.flag = &mac_vnode_check_rename_from_fp_flag },
434*18f67bc4SMateusz Guzik 	{ .offset = FPO(vnode_check_access),
435*18f67bc4SMateusz Guzik 		.flag = &mac_vnode_check_access_fp_flag },
43691061084SMateusz Guzik };
43791061084SMateusz Guzik 
43891061084SMateusz Guzik static void
43991061084SMateusz Guzik mac_policy_fastpath_enable(struct mac_policy_fastpath_elem *mpfe)
44091061084SMateusz Guzik {
44191061084SMateusz Guzik 
44291061084SMateusz Guzik 	MPASS(mpfe->count >= 0);
44391061084SMateusz Guzik 	mpfe->count++;
44491061084SMateusz Guzik 	if (mpfe->count == 1) {
44591061084SMateusz Guzik 		MPASS(*mpfe->flag == false);
44691061084SMateusz Guzik 		*mpfe->flag = true;
44791061084SMateusz Guzik 	}
44891061084SMateusz Guzik }
44991061084SMateusz Guzik 
45091061084SMateusz Guzik static void
45191061084SMateusz Guzik mac_policy_fastpath_disable(struct mac_policy_fastpath_elem *mpfe)
45291061084SMateusz Guzik {
45391061084SMateusz Guzik 
45491061084SMateusz Guzik 	MPASS(mpfe->count >= 1);
45591061084SMateusz Guzik 	mpfe->count--;
45691061084SMateusz Guzik 	if (mpfe->count == 0) {
45791061084SMateusz Guzik 		MPASS(*mpfe->flag == true);
45891061084SMateusz Guzik 		*mpfe->flag = false;
45991061084SMateusz Guzik 	}
46091061084SMateusz Guzik }
46191061084SMateusz Guzik 
46291061084SMateusz Guzik static void
46391061084SMateusz Guzik mac_policy_fastpath_register(struct mac_policy_conf *mpc)
46491061084SMateusz Guzik {
46591061084SMateusz Guzik 	struct mac_policy_fastpath_elem *mpfe;
46691061084SMateusz Guzik 	uintptr_t **ops;
46791061084SMateusz Guzik 	int i;
46891061084SMateusz Guzik 
46991061084SMateusz Guzik 	mac_policy_xlock_assert();
47091061084SMateusz Guzik 
47191061084SMateusz Guzik 	ops = (uintptr_t **)mpc->mpc_ops;
47291061084SMateusz Guzik 	for (i = 0; i < nitems(mac_policy_fastpath_array); i++) {
47391061084SMateusz Guzik 		mpfe = &mac_policy_fastpath_array[i];
47491061084SMateusz Guzik 		if (ops[mpfe->offset] != NULL)
47591061084SMateusz Guzik 			mac_policy_fastpath_enable(mpfe);
47691061084SMateusz Guzik 	}
47791061084SMateusz Guzik }
47891061084SMateusz Guzik 
47991061084SMateusz Guzik static void
48091061084SMateusz Guzik mac_policy_fastpath_unregister(struct mac_policy_conf *mpc)
48191061084SMateusz Guzik {
48291061084SMateusz Guzik 	struct mac_policy_fastpath_elem *mpfe;
48391061084SMateusz Guzik 	uintptr_t **ops;
48491061084SMateusz Guzik 	int i;
48591061084SMateusz Guzik 
48691061084SMateusz Guzik 	mac_policy_xlock_assert();
48791061084SMateusz Guzik 
48891061084SMateusz Guzik 	ops = (uintptr_t **)mpc->mpc_ops;
48991061084SMateusz Guzik 	for (i = 0; i < nitems(mac_policy_fastpath_array); i++) {
49091061084SMateusz Guzik 		mpfe = &mac_policy_fastpath_array[i];
49191061084SMateusz Guzik 		if (ops[mpfe->offset] != NULL)
49291061084SMateusz Guzik 			mac_policy_fastpath_disable(mpfe);
49391061084SMateusz Guzik 	}
49491061084SMateusz Guzik }
49591061084SMateusz Guzik 
49691061084SMateusz Guzik #undef FPO
49791061084SMateusz Guzik 
49895fab37eSRobert Watson static int
49995fab37eSRobert Watson mac_policy_register(struct mac_policy_conf *mpc)
50095fab37eSRobert Watson {
50195fab37eSRobert Watson 	struct mac_policy_conf *tmpc;
50241a17fe3SRobert Watson 	int error, slot, static_entry;
50395fab37eSRobert Watson 
50441a17fe3SRobert Watson 	error = 0;
50541a17fe3SRobert Watson 
50641a17fe3SRobert Watson 	/*
50717041e67SRobert Watson 	 * We don't technically need exclusive access while !mac_late, but
50817041e67SRobert Watson 	 * hold it for assertion consistency.
50941a17fe3SRobert Watson 	 */
51040202729SRobert Watson 	mac_policy_xlock();
51141a17fe3SRobert Watson 
51241a17fe3SRobert Watson 	/*
51317041e67SRobert Watson 	 * If the module can potentially be unloaded, or we're loading late,
51417041e67SRobert Watson 	 * we have to stick it in the non-static list and pay an extra
51517041e67SRobert Watson 	 * performance overhead.  Otherwise, we can pay a light locking cost
51617041e67SRobert Watson 	 * and stick it in the static list.
51741a17fe3SRobert Watson 	 */
51841a17fe3SRobert Watson 	static_entry = (!mac_late &&
51941a17fe3SRobert Watson 	    !(mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK));
52041a17fe3SRobert Watson 
52141a17fe3SRobert Watson 	if (static_entry) {
52241a17fe3SRobert Watson 		LIST_FOREACH(tmpc, &mac_static_policy_list, mpc_list) {
52341a17fe3SRobert Watson 			if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) {
52441a17fe3SRobert Watson 				error = EEXIST;
52541a17fe3SRobert Watson 				goto out;
52641a17fe3SRobert Watson 			}
52741a17fe3SRobert Watson 		}
52841a17fe3SRobert Watson 	} else {
52995fab37eSRobert Watson 		LIST_FOREACH(tmpc, &mac_policy_list, mpc_list) {
53095fab37eSRobert Watson 			if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) {
53141a17fe3SRobert Watson 				error = EEXIST;
53241a17fe3SRobert Watson 				goto out;
53341a17fe3SRobert Watson 			}
53495fab37eSRobert Watson 		}
53595fab37eSRobert Watson 	}
53695fab37eSRobert Watson 	if (mpc->mpc_field_off != NULL) {
537b2aef571SRobert Watson 		slot = ffs(mac_slot_offsets_free);
53895fab37eSRobert Watson 		if (slot == 0) {
53941a17fe3SRobert Watson 			error = ENOMEM;
54041a17fe3SRobert Watson 			goto out;
54195fab37eSRobert Watson 		}
54295fab37eSRobert Watson 		slot--;
543b2aef571SRobert Watson 		mac_slot_offsets_free &= ~(1 << slot);
54495fab37eSRobert Watson 		*mpc->mpc_field_off = slot;
54595fab37eSRobert Watson 	}
54695fab37eSRobert Watson 	mpc->mpc_runtime_flags |= MPC_RUNTIME_FLAG_REGISTERED;
54741a17fe3SRobert Watson 
54841a17fe3SRobert Watson 	/*
54917041e67SRobert Watson 	 * If we're loading a MAC module after the framework has initialized,
55017041e67SRobert Watson 	 * it has to go into the dynamic list.  If we're loading it before
55117041e67SRobert Watson 	 * we've finished initializing, it can go into the static list with
55217041e67SRobert Watson 	 * weaker locker requirements.
55341a17fe3SRobert Watson 	 */
55441a17fe3SRobert Watson 	if (static_entry)
55541a17fe3SRobert Watson 		LIST_INSERT_HEAD(&mac_static_policy_list, mpc, mpc_list);
55641a17fe3SRobert Watson 	else
55795fab37eSRobert Watson 		LIST_INSERT_HEAD(&mac_policy_list, mpc, mpc_list);
55895fab37eSRobert Watson 
55917041e67SRobert Watson 	/*
56017041e67SRobert Watson 	 * Per-policy initialization.  Currently, this takes place under the
56117041e67SRobert Watson 	 * exclusive lock, so policies must not sleep in their init method.
56217041e67SRobert Watson 	 * In the future, we may want to separate "init" from "start", with
563bc5ade0dSPedro F. Giffuni 	 * "init" occurring without the lock held.  Likewise, on tear-down,
56417041e67SRobert Watson 	 * breaking out "stop" from "destroy".
56517041e67SRobert Watson 	 */
56695fab37eSRobert Watson 	if (mpc->mpc_ops->mpo_init != NULL)
56795fab37eSRobert Watson 		(*(mpc->mpc_ops->mpo_init))(mpc);
56891061084SMateusz Guzik 
56991061084SMateusz Guzik 	mac_policy_fastpath_register(mpc);
57091061084SMateusz Guzik 
571f93bfb23SRobert Watson 	mac_policy_update();
57295fab37eSRobert Watson 
57336160958SMark Johnston 	SDT_PROBE1(mac, , policy, register, mpc);
57495fab37eSRobert Watson 	printf("Security policy loaded: %s (%s)\n", mpc->mpc_fullname,
57595fab37eSRobert Watson 	    mpc->mpc_name);
57695fab37eSRobert Watson 
57741a17fe3SRobert Watson out:
57840202729SRobert Watson 	mac_policy_xunlock();
57941a17fe3SRobert Watson 	return (error);
58095fab37eSRobert Watson }
58195fab37eSRobert Watson 
58295fab37eSRobert Watson static int
58395fab37eSRobert Watson mac_policy_unregister(struct mac_policy_conf *mpc)
58495fab37eSRobert Watson {
58595fab37eSRobert Watson 
586ea599aa0SRobert Watson 	/*
58717041e67SRobert Watson 	 * If we fail the load, we may get a request to unload.  Check to see
58817041e67SRobert Watson 	 * if we did the run-time registration, and if not, silently succeed.
589ea599aa0SRobert Watson 	 */
59040202729SRobert Watson 	mac_policy_xlock();
591ea599aa0SRobert Watson 	if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED) == 0) {
59240202729SRobert Watson 		mac_policy_xunlock();
593ea599aa0SRobert Watson 		return (0);
594ea599aa0SRobert Watson 	}
59595fab37eSRobert Watson #if 0
59695fab37eSRobert Watson 	/*
59795fab37eSRobert Watson 	 * Don't allow unloading modules with private data.
59895fab37eSRobert Watson 	 */
599ea599aa0SRobert Watson 	if (mpc->mpc_field_off != NULL) {
60040202729SRobert Watson 		mac_policy_xunlock();
60195fab37eSRobert Watson 		return (EBUSY);
602ea599aa0SRobert Watson 	}
60395fab37eSRobert Watson #endif
604ea599aa0SRobert Watson 	/*
60517041e67SRobert Watson 	 * Only allow the unload to proceed if the module is unloadable by
60617041e67SRobert Watson 	 * its own definition.
607ea599aa0SRobert Watson 	 */
608ea599aa0SRobert Watson 	if ((mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK) == 0) {
60940202729SRobert Watson 		mac_policy_xunlock();
61095fab37eSRobert Watson 		return (EBUSY);
611ea599aa0SRobert Watson 	}
61291061084SMateusz Guzik 
61391061084SMateusz Guzik 	mac_policy_fastpath_unregister(mpc);
61491061084SMateusz Guzik 
61595fab37eSRobert Watson 	if (mpc->mpc_ops->mpo_destroy != NULL)
61695fab37eSRobert Watson 		(*(mpc->mpc_ops->mpo_destroy))(mpc);
61795fab37eSRobert Watson 
61895fab37eSRobert Watson 	LIST_REMOVE(mpc, mpc_list);
6199aeffb2bSRobert Watson 	mpc->mpc_runtime_flags &= ~MPC_RUNTIME_FLAG_REGISTERED;
620f93bfb23SRobert Watson 	mac_policy_update();
62140202729SRobert Watson 	mac_policy_xunlock();
622a96acd1aSRobert Watson 
62336160958SMark Johnston 	SDT_PROBE1(mac, , policy, unregister, mpc);
62495fab37eSRobert Watson 	printf("Security policy unload: %s (%s)\n", mpc->mpc_fullname,
62595fab37eSRobert Watson 	    mpc->mpc_name);
62695fab37eSRobert Watson 
62795fab37eSRobert Watson 	return (0);
62895fab37eSRobert Watson }
62995fab37eSRobert Watson 
63095fab37eSRobert Watson /*
631c441d123SRobert Watson  * Allow MAC policy modules to register during boot, etc.
632c441d123SRobert Watson  */
633c441d123SRobert Watson int
634c441d123SRobert Watson mac_policy_modevent(module_t mod, int type, void *data)
635c441d123SRobert Watson {
636c441d123SRobert Watson 	struct mac_policy_conf *mpc;
637c441d123SRobert Watson 	int error;
638c441d123SRobert Watson 
639c441d123SRobert Watson 	error = 0;
640c441d123SRobert Watson 	mpc = (struct mac_policy_conf *) data;
641c441d123SRobert Watson 
642c441d123SRobert Watson #ifdef MAC_STATIC
643c441d123SRobert Watson 	if (mac_late) {
644c441d123SRobert Watson 		printf("mac_policy_modevent: MAC_STATIC and late\n");
645c441d123SRobert Watson 		return (EBUSY);
646c441d123SRobert Watson 	}
647c441d123SRobert Watson #endif
648c441d123SRobert Watson 
64936160958SMark Johnston 	SDT_PROBE2(mac, , policy, modevent, type, mpc);
650c441d123SRobert Watson 	switch (type) {
651c441d123SRobert Watson 	case MOD_LOAD:
652c441d123SRobert Watson 		if (mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_NOTLATE &&
653c441d123SRobert Watson 		    mac_late) {
654c441d123SRobert Watson 			printf("mac_policy_modevent: can't load %s policy "
655c441d123SRobert Watson 			    "after booting\n", mpc->mpc_name);
656c441d123SRobert Watson 			error = EBUSY;
657c441d123SRobert Watson 			break;
658c441d123SRobert Watson 		}
659c441d123SRobert Watson 		error = mac_policy_register(mpc);
660c441d123SRobert Watson 		break;
661c441d123SRobert Watson 	case MOD_UNLOAD:
662c441d123SRobert Watson 		/* Don't unregister the module if it was never registered. */
663c441d123SRobert Watson 		if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED)
664c441d123SRobert Watson 		    != 0)
665c441d123SRobert Watson 			error = mac_policy_unregister(mpc);
666c441d123SRobert Watson 		else
667c441d123SRobert Watson 			error = 0;
668c441d123SRobert Watson 		break;
669c441d123SRobert Watson 	default:
670c441d123SRobert Watson 		error = EOPNOTSUPP;
671c441d123SRobert Watson 		break;
672c441d123SRobert Watson 	}
673c441d123SRobert Watson 
674c441d123SRobert Watson 	return (error);
675c441d123SRobert Watson }
676c441d123SRobert Watson 
677c441d123SRobert Watson /*
67895fab37eSRobert Watson  * Define an error value precedence, and given two arguments, selects the
67995fab37eSRobert Watson  * value with the higher precedence.
68095fab37eSRobert Watson  */
6819e7bf51cSRobert Watson int
6829e7bf51cSRobert Watson mac_error_select(int error1, int error2)
68395fab37eSRobert Watson {
68495fab37eSRobert Watson 
68595fab37eSRobert Watson 	/* Certain decision-making errors take top priority. */
68695fab37eSRobert Watson 	if (error1 == EDEADLK || error2 == EDEADLK)
68795fab37eSRobert Watson 		return (EDEADLK);
68895fab37eSRobert Watson 
68995fab37eSRobert Watson 	/* Invalid arguments should be reported where possible. */
69095fab37eSRobert Watson 	if (error1 == EINVAL || error2 == EINVAL)
69195fab37eSRobert Watson 		return (EINVAL);
69295fab37eSRobert Watson 
69395fab37eSRobert Watson 	/* Precedence goes to "visibility", with both process and file. */
69495fab37eSRobert Watson 	if (error1 == ESRCH || error2 == ESRCH)
69595fab37eSRobert Watson 		return (ESRCH);
69695fab37eSRobert Watson 
69795fab37eSRobert Watson 	if (error1 == ENOENT || error2 == ENOENT)
69895fab37eSRobert Watson 		return (ENOENT);
69995fab37eSRobert Watson 
70095fab37eSRobert Watson 	/* Precedence goes to DAC/MAC protections. */
70195fab37eSRobert Watson 	if (error1 == EACCES || error2 == EACCES)
70295fab37eSRobert Watson 		return (EACCES);
70395fab37eSRobert Watson 
70495fab37eSRobert Watson 	/* Precedence goes to privilege. */
70595fab37eSRobert Watson 	if (error1 == EPERM || error2 == EPERM)
70695fab37eSRobert Watson 		return (EPERM);
70795fab37eSRobert Watson 
70895fab37eSRobert Watson 	/* Precedence goes to error over success; otherwise, arbitrary. */
70995fab37eSRobert Watson 	if (error1 != 0)
71095fab37eSRobert Watson 		return (error1);
71195fab37eSRobert Watson 	return (error2);
71295fab37eSRobert Watson }
71395fab37eSRobert Watson 
7145e7ce478SRobert Watson int
715f7b951a8SRobert Watson mac_check_structmac_consistent(struct mac *mac)
716f7b951a8SRobert Watson {
717f7b951a8SRobert Watson 
7186324de03SMark Johnston 	/* Require that labels have a non-zero length. */
7196324de03SMark Johnston 	if (mac->m_buflen > MAC_MAX_LABEL_BUF_LEN ||
7206324de03SMark Johnston 	    mac->m_buflen <= sizeof(""))
721f7b951a8SRobert Watson 		return (EINVAL);
722f7b951a8SRobert Watson 
723f7b951a8SRobert Watson 	return (0);
724f7b951a8SRobert Watson }
725f7b951a8SRobert Watson 
72695fab37eSRobert Watson SYSINIT(mac, SI_SUB_MAC, SI_ORDER_FIRST, mac_init, NULL);
72795fab37eSRobert Watson SYSINIT(mac_late, SI_SUB_MAC_LATE, SI_ORDER_FIRST, mac_late_init, NULL);
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