[apple/xnu.git] / bsd / kern / proc_uuid_policy.c

/*
 * Copyright (c) 2013 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/priv.h>

#include <sys/sysproto.h>
#include <sys/proc_uuid_policy.h>

#include <kern/locks.h>
#include <uuid/uuid.h>

#include <string.h>
#include <libkern/OSAtomic.h>

#define PROC_UUID_POLICY_DEBUG 0

#if PROC_UUID_POLICY_DEBUG
#define dprintf(...) printf(__VA_ARGS__)
#else
#define dprintf(...) do { } while(0)
#endif

static lck_grp_attr_t  *proc_uuid_policy_subsys_lck_grp_attr;
static lck_grp_t       *proc_uuid_policy_subsys_lck_grp;
static lck_attr_t      *proc_uuid_policy_subsys_lck_attr;
static lck_mtx_t        proc_uuid_policy_subsys_mutex;

#define PROC_UUID_POLICY_SUBSYS_LOCK() lck_mtx_lock(&proc_uuid_policy_subsys_mutex)
#define PROC_UUID_POLICY_SUBSYS_UNLOCK() lck_mtx_unlock(&proc_uuid_policy_subsys_mutex)

#define PROC_UUID_POLICY_HASH_SIZE 64
u_long proc_uuid_policy_hash_mask;

/* Assume first byte of UUIDs are evenly distributed */
#define UUIDHASH(uuid) (&proc_uuid_policy_hashtbl[uuid[0] & proc_uuid_policy_hash_mask])
static LIST_HEAD(proc_uuid_policy_hashhead, proc_uuid_policy_entry) *proc_uuid_policy_hashtbl;

/*
 * On modification, invalidate cached lookups by bumping the generation count.
 * Other calls will need to take the slowpath of taking
 * the subsystem lock.
 */
static volatile int32_t proc_uuid_policy_table_gencount;
#define BUMP_PROC_UUID_POLICY_GENERATION_COUNT() do {									\
		if (OSIncrementAtomic(&proc_uuid_policy_table_gencount) == (INT32_MAX - 1)) {	\
			proc_uuid_policy_table_gencount = 1;										\
		}																				\
	} while (0)

#define MAX_PROC_UUID_POLICY_COUNT 10240
static volatile int32_t proc_uuid_policy_count;

struct proc_uuid_policy_entry {
	LIST_ENTRY(proc_uuid_policy_entry) entries;
	uuid_t		uuid;	/* Mach-O executable UUID */
	uint32_t	flags;	/* policy flag for that UUID */
};

static int
proc_uuid_policy_insert(uuid_t uuid, uint32_t flags);

static struct proc_uuid_policy_entry *
proc_uuid_policy_remove_locked(uuid_t uuid, uint32_t flags, int *should_delete);

static int
proc_uuid_policy_remove(uuid_t uuid, uint32_t flags);

static struct proc_uuid_policy_entry *
proc_uuid_policy_lookup_locked(uuid_t uuid);

static int
proc_uuid_policy_clear(uint32_t flags);

void
proc_uuid_policy_init(void)
{
	proc_uuid_policy_subsys_lck_grp_attr = lck_grp_attr_alloc_init();
	proc_uuid_policy_subsys_lck_grp = lck_grp_alloc_init("proc_uuid_policy_subsys_lock", proc_uuid_policy_subsys_lck_grp_attr);
	proc_uuid_policy_subsys_lck_attr = lck_attr_alloc_init();
	lck_mtx_init(&proc_uuid_policy_subsys_mutex, proc_uuid_policy_subsys_lck_grp, proc_uuid_policy_subsys_lck_attr);

	proc_uuid_policy_hashtbl = hashinit(PROC_UUID_POLICY_HASH_SIZE, M_PROC_UUID_POLICY, &proc_uuid_policy_hash_mask);
	proc_uuid_policy_table_gencount = 1;
	proc_uuid_policy_count = 0;
}

static int
proc_uuid_policy_insert(uuid_t uuid, uint32_t flags)
{
	struct proc_uuid_policy_entry *entry, *foundentry = NULL;
	int error;

#if PROC_UUID_POLICY_DEBUG
	uuid_string_t uuidstr;
	uuid_unparse(uuid, uuidstr);
#endif

	if (uuid_is_null(uuid))
		return EINVAL;

	MALLOC(entry, struct proc_uuid_policy_entry *, sizeof(*entry), M_PROC_UUID_POLICY, M_WAITOK|M_ZERO);

	memcpy(entry->uuid, uuid, sizeof(uuid_t));
	entry->flags = flags;

	PROC_UUID_POLICY_SUBSYS_LOCK();

	foundentry = proc_uuid_policy_lookup_locked(uuid);
	if (foundentry != NULL) {
		/* The UUID is already in the list. Update the flags. */
		foundentry->flags |= flags;
		error = 0;
		FREE(entry, M_PROC_UUID_POLICY);
		entry = NULL;
		BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
	} else {
		/* Our target UUID is not in the list, insert it now */
		if (proc_uuid_policy_count < MAX_PROC_UUID_POLICY_COUNT) {
			LIST_INSERT_HEAD(UUIDHASH(uuid), entry, entries);
			proc_uuid_policy_count++;
			error = 0;
			BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
		} else {
			error = ENOMEM;
		}
	}

	PROC_UUID_POLICY_SUBSYS_UNLOCK();

	if (error) {
		FREE(entry, M_PROC_UUID_POLICY);
		dprintf("Failed to insert proc uuid policy (%s,0x%08x), table full\n", uuidstr, flags);
	} else {
		dprintf("Inserted proc uuid policy (%s,0x%08x)\n", uuidstr, flags);
	}

	return error;
}

static struct proc_uuid_policy_entry *
proc_uuid_policy_remove_locked(uuid_t uuid, uint32_t flags, int *should_delete)
{
	struct proc_uuid_policy_entry *foundentry = NULL;
	if (should_delete) {
		*should_delete = 0;
	}
	
	foundentry = proc_uuid_policy_lookup_locked(uuid);
	if (foundentry) {
		if (foundentry->flags == flags) {
			LIST_REMOVE(foundentry, entries);
			proc_uuid_policy_count--;
			if (should_delete) {
				*should_delete = 1;
			}
		} else {
			foundentry->flags &= ~flags;
		}
	}
	
	return foundentry;
}

static int
proc_uuid_policy_remove(uuid_t uuid, uint32_t flags)
{
	struct proc_uuid_policy_entry *delentry = NULL;
	int error;
	int should_delete = 0;

#if PROC_UUID_POLICY_DEBUG
	uuid_string_t uuidstr;
	uuid_unparse(uuid, uuidstr);
#endif

	if (uuid_is_null(uuid))
		return EINVAL;

	PROC_UUID_POLICY_SUBSYS_LOCK();

	delentry = proc_uuid_policy_remove_locked(uuid, flags, &should_delete);

	if (delentry) {
		error = 0;
		BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
	} else {
		error = ENOENT;
	}

	PROC_UUID_POLICY_SUBSYS_UNLOCK();

	/* If we had found a pre-existing entry, deallocate its memory now */
	if (delentry && should_delete) {
		FREE(delentry, M_PROC_UUID_POLICY);
	}

	if (error) {
		dprintf("Failed to remove proc uuid policy (%s), entry not present\n", uuidstr);
	} else {
		dprintf("Removed proc uuid policy (%s)\n", uuidstr);
	}

	return error;
}

static struct proc_uuid_policy_entry *
proc_uuid_policy_lookup_locked(uuid_t uuid)
{
	struct proc_uuid_policy_entry *tmpentry, *searchentry, *foundentry = NULL;
	
	LIST_FOREACH_SAFE(searchentry, UUIDHASH(uuid), entries, tmpentry) {
		if (0 == memcmp(searchentry->uuid, uuid, sizeof(uuid_t))) {
			foundentry = searchentry;
			break;
		}
	}
	
	return foundentry;
}

int
proc_uuid_policy_lookup(uuid_t uuid, uint32_t *flags, int32_t *gencount)
{
	struct proc_uuid_policy_entry *foundentry = NULL;
	int error;

#if PROC_UUID_POLICY_DEBUG
	uuid_string_t uuidstr;
	uuid_unparse(uuid, uuidstr);
#endif

	if (uuid_is_null(uuid) || !flags || !gencount)
		return EINVAL;

	if (*gencount == proc_uuid_policy_table_gencount) {
		/*
		 * Generation count hasn't changed, so old flags should be valid.
		 * We avoid taking the lock here by assuming any concurrent modifications
		 * to the table will invalidate the generation count.
		 */
		return 0;
	}

	PROC_UUID_POLICY_SUBSYS_LOCK();

	foundentry = proc_uuid_policy_lookup_locked(uuid);

	if (foundentry) {
		*flags = foundentry->flags;
		*gencount = proc_uuid_policy_table_gencount;
		error = 0;
	} else {
		error = ENOENT;
	}

	PROC_UUID_POLICY_SUBSYS_UNLOCK();

	if (error == 0) {
		dprintf("Looked up proc uuid policy (%s,0x%08x)\n", uuidstr, *flags);
	}

	return error;
}

static int
proc_uuid_policy_clear(uint32_t flags)
{
	struct proc_uuid_policy_entry *tmpentry, *searchentry;
	struct proc_uuid_policy_hashhead deletehead = LIST_HEAD_INITIALIZER(deletehead);
	unsigned long hashslot;
	
	/* If clear call includes no flags, infer 'No Cellular' flag */
	if (flags == PROC_UUID_POLICY_FLAGS_NONE) {
		flags = PROC_UUID_NO_CELLULAR;
	}

	PROC_UUID_POLICY_SUBSYS_LOCK();

	if (proc_uuid_policy_count > 0) {

		for (hashslot=0; hashslot <= proc_uuid_policy_hash_mask; hashslot++) {
			struct proc_uuid_policy_hashhead *headp = &proc_uuid_policy_hashtbl[hashslot];
			
			LIST_FOREACH_SAFE(searchentry, headp, entries, tmpentry) {
				if ((searchentry->flags & flags) == searchentry->flags) {
					/* We are clearing all flags for this entry, move entry to our delete list */
					LIST_REMOVE(searchentry, entries);
					proc_uuid_policy_count--;
					LIST_INSERT_HEAD(&deletehead, searchentry, entries);
				} else {
					searchentry->flags &= ~flags;
				}
			}
		}

		BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
	}

	PROC_UUID_POLICY_SUBSYS_UNLOCK();

	/* Memory deallocation happens after the hash lock is dropped */
	LIST_FOREACH_SAFE(searchentry, &deletehead, entries, tmpentry) {
		LIST_REMOVE(searchentry, entries);
		FREE(searchentry, M_PROC_UUID_POLICY);
	}

	dprintf("Clearing proc uuid policy table\n");
	
	return 0;
}

int proc_uuid_policy_kernel(uint32_t operation, uuid_t uuid, uint32_t flags)
{
	int error = 0;
	
	switch (operation) {
		case PROC_UUID_POLICY_OPERATION_CLEAR:
			error = proc_uuid_policy_clear(flags);
			break;
			
		case PROC_UUID_POLICY_OPERATION_ADD:
			error = proc_uuid_policy_insert(uuid, flags);
			break;
			
		case PROC_UUID_POLICY_OPERATION_REMOVE:
			error = proc_uuid_policy_remove(uuid, flags);
			break;
			
		default:
			error = EINVAL;
			break;
	}
	
	return error;
}

int proc_uuid_policy(struct proc *p __unused, struct proc_uuid_policy_args *uap, int32_t *retval __unused)
{
	int error = 0;
	uuid_t uuid;

	/* Need privilege for policy changes */
	error = priv_check_cred(kauth_cred_get(), PRIV_PROC_UUID_POLICY, 0);
	if (error) {
		dprintf("%s failed privilege check for proc_uuid_policy: %d\n", p->p_comm, error);
		return (error);
	} else {
		dprintf("%s succeeded privilege check for proc_uuid_policy\n", p->p_comm);
	}
	
	if (uap->uuid) {
		if (uap->uuidlen != sizeof(uuid_t))
			return ERANGE;
		
		error = copyin(uap->uuid, uuid, sizeof(uuid_t));
		if (error)
			return error;
	}
	
	return proc_uuid_policy_kernel(uap->operation, uuid, uap->flags);
}
Commit	Line	Data
39236c6e A	1	/*
	2	* Copyright (c) 2013 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29	#include <sys/param.h>
	30	#include <sys/malloc.h>
	31	#include <sys/queue.h>
	32	#include <sys/systm.h>
	33	#include <sys/priv.h>
	34
	35	#include <sys/sysproto.h>
	36	#include <sys/proc_uuid_policy.h>
	37
	38	#include <kern/locks.h>
	39	#include <uuid/uuid.h>
	40
	41	#include <string.h>
	42	#include <libkern/OSAtomic.h>
	43
	44	#define PROC_UUID_POLICY_DEBUG 0
	45
	46	#if PROC_UUID_POLICY_DEBUG
	47	#define dprintf(...) printf(__VA_ARGS__)
	48	#else
	49	#define dprintf(...) do { } while(0)
	50	#endif
	51
	52	static lck_grp_attr_t *proc_uuid_policy_subsys_lck_grp_attr;
	53	static lck_grp_t *proc_uuid_policy_subsys_lck_grp;
	54	static lck_attr_t *proc_uuid_policy_subsys_lck_attr;
	55	static lck_mtx_t proc_uuid_policy_subsys_mutex;
	56
	57	#define PROC_UUID_POLICY_SUBSYS_LOCK() lck_mtx_lock(&proc_uuid_policy_subsys_mutex)
	58	#define PROC_UUID_POLICY_SUBSYS_UNLOCK() lck_mtx_unlock(&proc_uuid_policy_subsys_mutex)
	59
	60	#define PROC_UUID_POLICY_HASH_SIZE 64
	61	u_long proc_uuid_policy_hash_mask;
	62
	63	/* Assume first byte of UUIDs are evenly distributed */
	64	#define UUIDHASH(uuid) (&proc_uuid_policy_hashtbl[uuid[0] & proc_uuid_policy_hash_mask])
65	static LIST_HEAD(proc_uuid_policy_hashhead, proc_uuid_policy_entry) *proc_uuid_policy_hashtbl;
66
67	/*
68	* On modification, invalidate cached lookups by bumping the generation count.
69	* Other calls will need to take the slowpath of taking
70	* the subsystem lock.
71	*/
72	static volatile int32_t proc_uuid_policy_table_gencount;
73	#define BUMP_PROC_UUID_POLICY_GENERATION_COUNT() do { \
74	if (OSIncrementAtomic(&proc_uuid_policy_table_gencount) == (INT32_MAX - 1)) { \
75	proc_uuid_policy_table_gencount = 1; \
76	} \
77	} while (0)
78
79	#define MAX_PROC_UUID_POLICY_COUNT 10240
80	static volatile int32_t proc_uuid_policy_count;
81
82	struct proc_uuid_policy_entry {
83	LIST_ENTRY(proc_uuid_policy_entry) entries;
84	uuid_t uuid; /* Mach-O executable UUID */
85	uint32_t flags; /* policy flag for that UUID */
86	};
87
88	static int
89	proc_uuid_policy_insert(uuid_t uuid, uint32_t flags);
90
91	static struct proc_uuid_policy_entry *
fe8ab488	92	proc_uuid_policy_remove_locked(uuid_t uuid, uint32_t flags, int *should_delete);
39236c6e A	93
39236c6e A	94	static int
fe8ab488 A	95	proc_uuid_policy_remove(uuid_t uuid, uint32_t flags);
	96
	97	static struct proc_uuid_policy_entry *
	98	proc_uuid_policy_lookup_locked(uuid_t uuid);
39236c6e A	99
39236c6e A	100	static int
fe8ab488	101	proc_uuid_policy_clear(uint32_t flags);
39236c6e A	102
	103	void
	104	proc_uuid_policy_init(void)
	105	{
	106	proc_uuid_policy_subsys_lck_grp_attr = lck_grp_attr_alloc_init();
	107	proc_uuid_policy_subsys_lck_grp = lck_grp_alloc_init("proc_uuid_policy_subsys_lock", proc_uuid_policy_subsys_lck_grp_attr);
	108	proc_uuid_policy_subsys_lck_attr = lck_attr_alloc_init();
	109	lck_mtx_init(&proc_uuid_policy_subsys_mutex, proc_uuid_policy_subsys_lck_grp, proc_uuid_policy_subsys_lck_attr);
	110
	111	proc_uuid_policy_hashtbl = hashinit(PROC_UUID_POLICY_HASH_SIZE, M_PROC_UUID_POLICY, &proc_uuid_policy_hash_mask);
	112	proc_uuid_policy_table_gencount = 1;
	113	proc_uuid_policy_count = 0;
	114	}
	115
	116	static int
	117	proc_uuid_policy_insert(uuid_t uuid, uint32_t flags)
	118	{
fe8ab488	119	struct proc_uuid_policy_entry entry, foundentry = NULL;
39236c6e A	120	int error;
	121
	122	#if PROC_UUID_POLICY_DEBUG
	123	uuid_string_t uuidstr;
	124	uuid_unparse(uuid, uuidstr);
	125	#endif
	126
	127	if (uuid_is_null(uuid))
	128	return EINVAL;
	129
	130	MALLOC(entry, struct proc_uuid_policy_entry , sizeof(entry), M_PROC_UUID_POLICY, M_WAITOK\|M_ZERO);
	131
	132	memcpy(entry->uuid, uuid, sizeof(uuid_t));
	133	entry->flags = flags;
	134
	135	PROC_UUID_POLICY_SUBSYS_LOCK();
	136
fe8ab488 A	137	foundentry = proc_uuid_policy_lookup_locked(uuid);
	138	if (foundentry != NULL) {
	139	/* The UUID is already in the list. Update the flags. */
	140	foundentry->flags \|= flags;
39236c6e	141	error = 0;
fe8ab488 A	142	FREE(entry, M_PROC_UUID_POLICY);
fe8ab488 A	143	entry = NULL;
39236c6e A	144	BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
39236c6e A	145	} else {
fe8ab488 A	146	/* Our target UUID is not in the list, insert it now */
	147	if (proc_uuid_policy_count < MAX_PROC_UUID_POLICY_COUNT) {
	148	LIST_INSERT_HEAD(UUIDHASH(uuid), entry, entries);
	149	proc_uuid_policy_count++;
	150	error = 0;
	151	BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
	152	} else {
	153	error = ENOMEM;
	154	}
39236c6e A	155	}
	156
	157	PROC_UUID_POLICY_SUBSYS_UNLOCK();
	158
39236c6e A	159	if (error) {
	160	FREE(entry, M_PROC_UUID_POLICY);
	161	dprintf("Failed to insert proc uuid policy (%s,0x%08x), table full\n", uuidstr, flags);
	162	} else {
	163	dprintf("Inserted proc uuid policy (%s,0x%08x)\n", uuidstr, flags);
	164	}
	165
	166	return error;
	167	}
	168
	169	static struct proc_uuid_policy_entry *
fe8ab488	170	proc_uuid_policy_remove_locked(uuid_t uuid, uint32_t flags, int *should_delete)
39236c6e	171	{
fe8ab488 A	172	struct proc_uuid_policy_entry *foundentry = NULL;
	173	if (should_delete) {
	174	*should_delete = 0;
	175	}
	176
	177	foundentry = proc_uuid_policy_lookup_locked(uuid);
	178	if (foundentry) {
	179	if (foundentry->flags == flags) {
	180	LIST_REMOVE(foundentry, entries);
39236c6e	181	proc_uuid_policy_count--;
fe8ab488 A	182	if (should_delete) {
	183	*should_delete = 1;
	184	}
	185	} else {
	186	foundentry->flags &= ~flags;
39236c6e A	187	}
39236c6e A	188	}
fe8ab488 A	189
fe8ab488 A	190	return foundentry;
39236c6e A	191	}
	192
	193	static int
fe8ab488	194	proc_uuid_policy_remove(uuid_t uuid, uint32_t flags)
39236c6e A	195	{
	196	struct proc_uuid_policy_entry *delentry = NULL;
	197	int error;
fe8ab488	198	int should_delete = 0;
39236c6e A	199
	200	#if PROC_UUID_POLICY_DEBUG
	201	uuid_string_t uuidstr;
	202	uuid_unparse(uuid, uuidstr);
	203	#endif
	204
	205	if (uuid_is_null(uuid))
	206	return EINVAL;
	207
	208	PROC_UUID_POLICY_SUBSYS_LOCK();
	209
fe8ab488	210	delentry = proc_uuid_policy_remove_locked(uuid, flags, &should_delete);
39236c6e A	211
	212	if (delentry) {
	213	error = 0;
	214	BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
	215	} else {
	216	error = ENOENT;
	217	}
	218
	219	PROC_UUID_POLICY_SUBSYS_UNLOCK();
	220
	221	/* If we had found a pre-existing entry, deallocate its memory now */
fe8ab488	222	if (delentry && should_delete) {
39236c6e A	223	FREE(delentry, M_PROC_UUID_POLICY);
	224	}
	225
	226	if (error) {
	227	dprintf("Failed to remove proc uuid policy (%s), entry not present\n", uuidstr);
	228	} else {
	229	dprintf("Removed proc uuid policy (%s)\n", uuidstr);
	230	}
	231
	232	return error;
	233	}
	234
fe8ab488 A	235	static struct proc_uuid_policy_entry *
	236	proc_uuid_policy_lookup_locked(uuid_t uuid)
	237	{
	238	struct proc_uuid_policy_entry tmpentry, searchentry, *foundentry = NULL;
	239
	240	LIST_FOREACH_SAFE(searchentry, UUIDHASH(uuid), entries, tmpentry) {
	241	if (0 == memcmp(searchentry->uuid, uuid, sizeof(uuid_t))) {
	242	foundentry = searchentry;
	243	break;
	244	}
	245	}
	246
	247	return foundentry;
	248	}
	249
39236c6e A	250	int
	251	proc_uuid_policy_lookup(uuid_t uuid, uint32_t flags, int32_t gencount)
	252	{
fe8ab488	253	struct proc_uuid_policy_entry *foundentry = NULL;
39236c6e A	254	int error;
	255
	256	#if PROC_UUID_POLICY_DEBUG
	257	uuid_string_t uuidstr;
	258	uuid_unparse(uuid, uuidstr);
	259	#endif
	260
	261	if (uuid_is_null(uuid) \|\| !flags \|\| !gencount)
	262	return EINVAL;
	263
	264	if (*gencount == proc_uuid_policy_table_gencount) {
	265	/*
	266	* Generation count hasn't changed, so old flags should be valid.
	267	* We avoid taking the lock here by assuming any concurrent modifications
	268	* to the table will invalidate the generation count.
	269	*/
	270	return 0;
	271	}
	272
	273	PROC_UUID_POLICY_SUBSYS_LOCK();
	274
fe8ab488	275	foundentry = proc_uuid_policy_lookup_locked(uuid);
39236c6e A	276
	277	if (foundentry) {
	278	*flags = foundentry->flags;
	279	*gencount = proc_uuid_policy_table_gencount;
	280	error = 0;
	281	} else {
	282	error = ENOENT;
	283	}
	284
	285	PROC_UUID_POLICY_SUBSYS_UNLOCK();
	286
	287	if (error == 0) {
	288	dprintf("Looked up proc uuid policy (%s,0x%08x)\n", uuidstr, *flags);
	289	}
	290
	291	return error;
	292	}
	293
	294	static int
fe8ab488	295	proc_uuid_policy_clear(uint32_t flags)
39236c6e A	296	{
	297	struct proc_uuid_policy_entry tmpentry, searchentry;
	298	struct proc_uuid_policy_hashhead deletehead = LIST_HEAD_INITIALIZER(deletehead);
	299	unsigned long hashslot;
fe8ab488 A	300
	301	/* If clear call includes no flags, infer 'No Cellular' flag */
	302	if (flags == PROC_UUID_POLICY_FLAGS_NONE) {
	303	flags = PROC_UUID_NO_CELLULAR;
	304	}
39236c6e A	305
	306	PROC_UUID_POLICY_SUBSYS_LOCK();
	307
	308	if (proc_uuid_policy_count > 0) {
	309
	310	for (hashslot=0; hashslot <= proc_uuid_policy_hash_mask; hashslot++) {
	311	struct proc_uuid_policy_hashhead *headp = &proc_uuid_policy_hashtbl[hashslot];
	312
	313	LIST_FOREACH_SAFE(searchentry, headp, entries, tmpentry) {
fe8ab488 A	314	if ((searchentry->flags & flags) == searchentry->flags) {
	315	/* We are clearing all flags for this entry, move entry to our delete list */
	316	LIST_REMOVE(searchentry, entries);
	317	proc_uuid_policy_count--;
	318	LIST_INSERT_HEAD(&deletehead, searchentry, entries);
	319	} else {
	320	searchentry->flags &= ~flags;
	321	}
39236c6e A	322	}
	323	}
	324
	325	BUMP_PROC_UUID_POLICY_GENERATION_COUNT();
	326	}
	327
	328	PROC_UUID_POLICY_SUBSYS_UNLOCK();
	329
	330	/* Memory deallocation happens after the hash lock is dropped */
	331	LIST_FOREACH_SAFE(searchentry, &deletehead, entries, tmpentry) {
	332	LIST_REMOVE(searchentry, entries);
	333	FREE(searchentry, M_PROC_UUID_POLICY);
	334	}
	335
	336	dprintf("Clearing proc uuid policy table\n");
	337
	338	return 0;
	339	}
	340
fe8ab488 A	341	int proc_uuid_policy_kernel(uint32_t operation, uuid_t uuid, uint32_t flags)
	342	{
	343	int error = 0;
	344
	345	switch (operation) {
	346	case PROC_UUID_POLICY_OPERATION_CLEAR:
	347	error = proc_uuid_policy_clear(flags);
	348	break;
	349
	350	case PROC_UUID_POLICY_OPERATION_ADD:
	351	error = proc_uuid_policy_insert(uuid, flags);
	352	break;
	353
	354	case PROC_UUID_POLICY_OPERATION_REMOVE:
	355	error = proc_uuid_policy_remove(uuid, flags);
	356	break;
	357
	358	default:
	359	error = EINVAL;
	360	break;
	361	}
	362
	363	return error;
	364	}
	365
39236c6e A	366	int proc_uuid_policy(struct proc p __unused, struct proc_uuid_policy_args uap, int32_t *retval __unused)
	367	{
	368	int error = 0;
	369	uuid_t uuid;
	370
	371	/* Need privilege for policy changes */
	372	error = priv_check_cred(kauth_cred_get(), PRIV_PROC_UUID_POLICY, 0);
	373	if (error) {
	374	dprintf("%s failed privilege check for proc_uuid_policy: %d\n", p->p_comm, error);
	375	return (error);
	376	} else {
	377	dprintf("%s succeeded privilege check for proc_uuid_policy\n", p->p_comm);
	378	}
	379
fe8ab488 A	380	if (uap->uuid) {
	381	if (uap->uuidlen != sizeof(uuid_t))
	382	return ERANGE;
	383
	384	error = copyin(uap->uuid, uuid, sizeof(uuid_t));
	385	if (error)
	386	return error;
39236c6e	387	}
fe8ab488 A	388
fe8ab488 A	389	return proc_uuid_policy_kernel(uap->operation, uuid, uap->flags);
39236c6e	390	}