fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / security / selinux / avc.c
blob81b3dff3cbf0597a4b7464ee9d6f3fdcd121d2b8
1 /*
2 * Implementation of the kernel access vector cache (AVC).
4 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
7 * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com>
8 * Replaced the avc_lock spinlock by RCU.
10 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2,
14 * as published by the Free Software Foundation.
16 #include <linux/types.h>
17 #include <linux/stddef.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <linux/fs.h>
21 #include <linux/dcache.h>
22 #include <linux/init.h>
23 #include <linux/skbuff.h>
24 #include <linux/percpu.h>
25 #include <net/sock.h>
26 #include <linux/un.h>
27 #include <net/af_unix.h>
28 #include <linux/ip.h>
29 #include <linux/audit.h>
30 #include <linux/ipv6.h>
31 #include <net/ipv6.h>
32 #include "avc.h"
33 #include "avc_ss.h"
35 static const struct av_perm_to_string av_perm_to_string[] = {
36 #define S_(c, v, s) { c, v, s },
37 #include "av_perm_to_string.h"
38 #undef S_
41 static const char *class_to_string[] = {
42 #define S_(s) s,
43 #include "class_to_string.h"
44 #undef S_
47 #define TB_(s) static const char * s [] = {
48 #define TE_(s) };
49 #define S_(s) s,
50 #include "common_perm_to_string.h"
51 #undef TB_
52 #undef TE_
53 #undef S_
55 static const struct av_inherit av_inherit[] = {
56 #define S_(c, i, b) { c, common_##i##_perm_to_string, b },
57 #include "av_inherit.h"
58 #undef S_
61 const struct selinux_class_perm selinux_class_perm = {
62 av_perm_to_string,
63 ARRAY_SIZE(av_perm_to_string),
64 class_to_string,
65 ARRAY_SIZE(class_to_string),
66 av_inherit,
67 ARRAY_SIZE(av_inherit)
70 #define AVC_CACHE_SLOTS 512
71 #define AVC_DEF_CACHE_THRESHOLD 512
72 #define AVC_CACHE_RECLAIM 16
74 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
75 #define avc_cache_stats_incr(field) \
76 do { \
77 per_cpu(avc_cache_stats, get_cpu()).field++; \
78 put_cpu(); \
79 } while (0)
80 #else
81 #define avc_cache_stats_incr(field) do {} while (0)
82 #endif
84 struct avc_entry {
85 u32 ssid;
86 u32 tsid;
87 u16 tclass;
88 struct av_decision avd;
89 atomic_t used; /* used recently */
92 struct avc_node {
93 struct avc_entry ae;
94 struct list_head list;
95 struct rcu_head rhead;
98 struct avc_cache {
99 struct list_head slots[AVC_CACHE_SLOTS];
100 spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */
101 atomic_t lru_hint; /* LRU hint for reclaim scan */
102 atomic_t active_nodes;
103 u32 latest_notif; /* latest revocation notification */
106 struct avc_callback_node {
107 int (*callback) (u32 event, u32 ssid, u32 tsid,
108 u16 tclass, u32 perms,
109 u32 *out_retained);
110 u32 events;
111 u32 ssid;
112 u32 tsid;
113 u16 tclass;
114 u32 perms;
115 struct avc_callback_node *next;
118 /* Exported via selinufs */
119 unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD;
121 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
122 DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 };
123 #endif
125 static struct avc_cache avc_cache;
126 static struct avc_callback_node *avc_callbacks;
127 static struct kmem_cache *avc_node_cachep;
129 static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
131 return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1);
135 * avc_dump_av - Display an access vector in human-readable form.
136 * @tclass: target security class
137 * @av: access vector
139 static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
141 const char **common_pts = NULL;
142 u32 common_base = 0;
143 int i, i2, perm;
145 if (av == 0) {
146 audit_log_format(ab, " null");
147 return;
150 for (i = 0; i < ARRAY_SIZE(av_inherit); i++) {
151 if (av_inherit[i].tclass == tclass) {
152 common_pts = av_inherit[i].common_pts;
153 common_base = av_inherit[i].common_base;
154 break;
158 audit_log_format(ab, " {");
159 i = 0;
160 perm = 1;
161 while (perm < common_base) {
162 if (perm & av) {
163 audit_log_format(ab, " %s", common_pts[i]);
164 av &= ~perm;
166 i++;
167 perm <<= 1;
170 while (i < sizeof(av) * 8) {
171 if (perm & av) {
172 for (i2 = 0; i2 < ARRAY_SIZE(av_perm_to_string); i2++) {
173 if ((av_perm_to_string[i2].tclass == tclass) &&
174 (av_perm_to_string[i2].value == perm))
175 break;
177 if (i2 < ARRAY_SIZE(av_perm_to_string)) {
178 audit_log_format(ab, " %s",
179 av_perm_to_string[i2].name);
180 av &= ~perm;
183 i++;
184 perm <<= 1;
187 if (av)
188 audit_log_format(ab, " 0x%x", av);
190 audit_log_format(ab, " }");
194 * avc_dump_query - Display a SID pair and a class in human-readable form.
195 * @ssid: source security identifier
196 * @tsid: target security identifier
197 * @tclass: target security class
199 static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass)
201 int rc;
202 char *scontext;
203 u32 scontext_len;
205 rc = security_sid_to_context(ssid, &scontext, &scontext_len);
206 if (rc)
207 audit_log_format(ab, "ssid=%d", ssid);
208 else {
209 audit_log_format(ab, "scontext=%s", scontext);
210 kfree(scontext);
213 rc = security_sid_to_context(tsid, &scontext, &scontext_len);
214 if (rc)
215 audit_log_format(ab, " tsid=%d", tsid);
216 else {
217 audit_log_format(ab, " tcontext=%s", scontext);
218 kfree(scontext);
221 BUG_ON(tclass >= ARRAY_SIZE(class_to_string) || !class_to_string[tclass]);
222 audit_log_format(ab, " tclass=%s", class_to_string[tclass]);
226 * avc_init - Initialize the AVC.
228 * Initialize the access vector cache.
230 void __init avc_init(void)
232 int i;
234 for (i = 0; i < AVC_CACHE_SLOTS; i++) {
235 INIT_LIST_HEAD(&avc_cache.slots[i]);
236 spin_lock_init(&avc_cache.slots_lock[i]);
238 atomic_set(&avc_cache.active_nodes, 0);
239 atomic_set(&avc_cache.lru_hint, 0);
241 avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node),
242 0, SLAB_PANIC, NULL);
244 audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n");
247 int avc_get_hash_stats(char *page)
249 int i, chain_len, max_chain_len, slots_used;
250 struct avc_node *node;
252 rcu_read_lock();
254 slots_used = 0;
255 max_chain_len = 0;
256 for (i = 0; i < AVC_CACHE_SLOTS; i++) {
257 if (!list_empty(&avc_cache.slots[i])) {
258 slots_used++;
259 chain_len = 0;
260 list_for_each_entry_rcu(node, &avc_cache.slots[i], list)
261 chain_len++;
262 if (chain_len > max_chain_len)
263 max_chain_len = chain_len;
267 rcu_read_unlock();
269 return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n"
270 "longest chain: %d\n",
271 atomic_read(&avc_cache.active_nodes),
272 slots_used, AVC_CACHE_SLOTS, max_chain_len);
275 static void avc_node_free(struct rcu_head *rhead)
277 struct avc_node *node = container_of(rhead, struct avc_node, rhead);
278 kmem_cache_free(avc_node_cachep, node);
279 avc_cache_stats_incr(frees);
282 static void avc_node_delete(struct avc_node *node)
284 list_del_rcu(&node->list);
285 call_rcu(&node->rhead, avc_node_free);
286 atomic_dec(&avc_cache.active_nodes);
289 static void avc_node_kill(struct avc_node *node)
291 kmem_cache_free(avc_node_cachep, node);
292 avc_cache_stats_incr(frees);
293 atomic_dec(&avc_cache.active_nodes);
296 static void avc_node_replace(struct avc_node *new, struct avc_node *old)
298 list_replace_rcu(&old->list, &new->list);
299 call_rcu(&old->rhead, avc_node_free);
300 atomic_dec(&avc_cache.active_nodes);
303 static inline int avc_reclaim_node(void)
305 struct avc_node *node;
306 int hvalue, try, ecx;
307 unsigned long flags;
309 for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) {
310 hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1);
312 if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags))
313 continue;
315 list_for_each_entry(node, &avc_cache.slots[hvalue], list) {
316 if (atomic_dec_and_test(&node->ae.used)) {
317 /* Recently Unused */
318 avc_node_delete(node);
319 avc_cache_stats_incr(reclaims);
320 ecx++;
321 if (ecx >= AVC_CACHE_RECLAIM) {
322 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
323 goto out;
327 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
329 out:
330 return ecx;
333 static struct avc_node *avc_alloc_node(void)
335 struct avc_node *node;
337 node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC);
338 if (!node)
339 goto out;
341 INIT_RCU_HEAD(&node->rhead);
342 INIT_LIST_HEAD(&node->list);
343 atomic_set(&node->ae.used, 1);
344 avc_cache_stats_incr(allocations);
346 if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold)
347 avc_reclaim_node();
349 out:
350 return node;
353 static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
355 node->ae.ssid = ssid;
356 node->ae.tsid = tsid;
357 node->ae.tclass = tclass;
358 memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd));
361 static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass)
363 struct avc_node *node, *ret = NULL;
364 int hvalue;
366 hvalue = avc_hash(ssid, tsid, tclass);
367 list_for_each_entry_rcu(node, &avc_cache.slots[hvalue], list) {
368 if (ssid == node->ae.ssid &&
369 tclass == node->ae.tclass &&
370 tsid == node->ae.tsid) {
371 ret = node;
372 break;
376 if (ret == NULL) {
377 /* cache miss */
378 goto out;
381 /* cache hit */
382 if (atomic_read(&ret->ae.used) != 1)
383 atomic_set(&ret->ae.used, 1);
384 out:
385 return ret;
389 * avc_lookup - Look up an AVC entry.
390 * @ssid: source security identifier
391 * @tsid: target security identifier
392 * @tclass: target security class
393 * @requested: requested permissions, interpreted based on @tclass
395 * Look up an AVC entry that is valid for the
396 * @requested permissions between the SID pair
397 * (@ssid, @tsid), interpreting the permissions
398 * based on @tclass. If a valid AVC entry exists,
399 * then this function return the avc_node.
400 * Otherwise, this function returns NULL.
402 static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested)
404 struct avc_node *node;
406 avc_cache_stats_incr(lookups);
407 node = avc_search_node(ssid, tsid, tclass);
409 if (node && ((node->ae.avd.decided & requested) == requested)) {
410 avc_cache_stats_incr(hits);
411 goto out;
414 node = NULL;
415 avc_cache_stats_incr(misses);
416 out:
417 return node;
420 static int avc_latest_notif_update(int seqno, int is_insert)
422 int ret = 0;
423 static DEFINE_SPINLOCK(notif_lock);
424 unsigned long flag;
426 spin_lock_irqsave(&notif_lock, flag);
427 if (is_insert) {
428 if (seqno < avc_cache.latest_notif) {
429 printk(KERN_WARNING "avc: seqno %d < latest_notif %d\n",
430 seqno, avc_cache.latest_notif);
431 ret = -EAGAIN;
433 } else {
434 if (seqno > avc_cache.latest_notif)
435 avc_cache.latest_notif = seqno;
437 spin_unlock_irqrestore(&notif_lock, flag);
439 return ret;
443 * avc_insert - Insert an AVC entry.
444 * @ssid: source security identifier
445 * @tsid: target security identifier
446 * @tclass: target security class
447 * @ae: AVC entry
449 * Insert an AVC entry for the SID pair
450 * (@ssid, @tsid) and class @tclass.
451 * The access vectors and the sequence number are
452 * normally provided by the security server in
453 * response to a security_compute_av() call. If the
454 * sequence number @ae->avd.seqno is not less than the latest
455 * revocation notification, then the function copies
456 * the access vectors into a cache entry, returns
457 * avc_node inserted. Otherwise, this function returns NULL.
459 static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
461 struct avc_node *pos, *node = NULL;
462 int hvalue;
463 unsigned long flag;
465 if (avc_latest_notif_update(ae->avd.seqno, 1))
466 goto out;
468 node = avc_alloc_node();
469 if (node) {
470 hvalue = avc_hash(ssid, tsid, tclass);
471 avc_node_populate(node, ssid, tsid, tclass, ae);
473 spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
474 list_for_each_entry(pos, &avc_cache.slots[hvalue], list) {
475 if (pos->ae.ssid == ssid &&
476 pos->ae.tsid == tsid &&
477 pos->ae.tclass == tclass) {
478 avc_node_replace(node, pos);
479 goto found;
482 list_add_rcu(&node->list, &avc_cache.slots[hvalue]);
483 found:
484 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
486 out:
487 return node;
490 static inline void avc_print_ipv6_addr(struct audit_buffer *ab,
491 struct in6_addr *addr, __be16 port,
492 char *name1, char *name2)
494 if (!ipv6_addr_any(addr))
495 audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr));
496 if (port)
497 audit_log_format(ab, " %s=%d", name2, ntohs(port));
500 static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
501 __be16 port, char *name1, char *name2)
503 if (addr)
504 audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr));
505 if (port)
506 audit_log_format(ab, " %s=%d", name2, ntohs(port));
510 * avc_audit - Audit the granting or denial of permissions.
511 * @ssid: source security identifier
512 * @tsid: target security identifier
513 * @tclass: target security class
514 * @requested: requested permissions
515 * @avd: access vector decisions
516 * @result: result from avc_has_perm_noaudit
517 * @a: auxiliary audit data
519 * Audit the granting or denial of permissions in accordance
520 * with the policy. This function is typically called by
521 * avc_has_perm() after a permission check, but can also be
522 * called directly by callers who use avc_has_perm_noaudit()
523 * in order to separate the permission check from the auditing.
524 * For example, this separation is useful when the permission check must
525 * be performed under a lock, to allow the lock to be released
526 * before calling the auditing code.
528 void avc_audit(u32 ssid, u32 tsid,
529 u16 tclass, u32 requested,
530 struct av_decision *avd, int result, struct avc_audit_data *a)
532 struct task_struct *tsk = current;
533 struct inode *inode = NULL;
534 u32 denied, audited;
535 struct audit_buffer *ab;
537 denied = requested & ~avd->allowed;
538 if (denied) {
539 audited = denied;
540 if (!(audited & avd->auditdeny))
541 return;
542 } else if (result) {
543 audited = denied = requested;
544 } else {
545 audited = requested;
546 if (!(audited & avd->auditallow))
547 return;
550 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC);
551 if (!ab)
552 return; /* audit_panic has been called */
553 audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted");
554 avc_dump_av(ab, tclass,audited);
555 audit_log_format(ab, " for ");
556 if (a && a->tsk)
557 tsk = a->tsk;
558 if (tsk && tsk->pid) {
559 audit_log_format(ab, " pid=%d comm=", tsk->pid);
560 audit_log_untrustedstring(ab, tsk->comm);
562 if (a) {
563 switch (a->type) {
564 case AVC_AUDIT_DATA_IPC:
565 audit_log_format(ab, " key=%d", a->u.ipc_id);
566 break;
567 case AVC_AUDIT_DATA_CAP:
568 audit_log_format(ab, " capability=%d", a->u.cap);
569 break;
570 case AVC_AUDIT_DATA_FS:
571 if (a->u.fs.dentry) {
572 struct dentry *dentry = a->u.fs.dentry;
573 if (a->u.fs.mnt) {
574 audit_log_d_path(ab, "path=", dentry, a->u.fs.mnt);
575 } else {
576 audit_log_format(ab, " name=");
577 audit_log_untrustedstring(ab, dentry->d_name.name);
579 inode = dentry->d_inode;
580 } else if (a->u.fs.inode) {
581 struct dentry *dentry;
582 inode = a->u.fs.inode;
583 dentry = d_find_alias(inode);
584 if (dentry) {
585 audit_log_format(ab, " name=");
586 audit_log_untrustedstring(ab, dentry->d_name.name);
587 dput(dentry);
590 if (inode)
591 audit_log_format(ab, " dev=%s ino=%lu",
592 inode->i_sb->s_id,
593 inode->i_ino);
594 break;
595 case AVC_AUDIT_DATA_NET:
596 if (a->u.net.sk) {
597 struct sock *sk = a->u.net.sk;
598 struct unix_sock *u;
599 int len = 0;
600 char *p = NULL;
602 switch (sk->sk_family) {
603 case AF_INET: {
604 struct inet_sock *inet = inet_sk(sk);
606 avc_print_ipv4_addr(ab, inet->rcv_saddr,
607 inet->sport,
608 "laddr", "lport");
609 avc_print_ipv4_addr(ab, inet->daddr,
610 inet->dport,
611 "faddr", "fport");
612 break;
614 case AF_INET6: {
615 struct inet_sock *inet = inet_sk(sk);
616 struct ipv6_pinfo *inet6 = inet6_sk(sk);
618 avc_print_ipv6_addr(ab, &inet6->rcv_saddr,
619 inet->sport,
620 "laddr", "lport");
621 avc_print_ipv6_addr(ab, &inet6->daddr,
622 inet->dport,
623 "faddr", "fport");
624 break;
626 case AF_UNIX:
627 u = unix_sk(sk);
628 if (u->dentry) {
629 audit_log_d_path(ab, "path=",
630 u->dentry, u->mnt);
631 break;
633 if (!u->addr)
634 break;
635 len = u->addr->len-sizeof(short);
636 p = &u->addr->name->sun_path[0];
637 audit_log_format(ab, " path=");
638 if (*p)
639 audit_log_untrustedstring(ab, p);
640 else
641 audit_log_hex(ab, p, len);
642 break;
646 switch (a->u.net.family) {
647 case AF_INET:
648 avc_print_ipv4_addr(ab, a->u.net.v4info.saddr,
649 a->u.net.sport,
650 "saddr", "src");
651 avc_print_ipv4_addr(ab, a->u.net.v4info.daddr,
652 a->u.net.dport,
653 "daddr", "dest");
654 break;
655 case AF_INET6:
656 avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr,
657 a->u.net.sport,
658 "saddr", "src");
659 avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr,
660 a->u.net.dport,
661 "daddr", "dest");
662 break;
664 if (a->u.net.netif)
665 audit_log_format(ab, " netif=%s",
666 a->u.net.netif);
667 break;
670 audit_log_format(ab, " ");
671 avc_dump_query(ab, ssid, tsid, tclass);
672 audit_log_end(ab);
676 * avc_add_callback - Register a callback for security events.
677 * @callback: callback function
678 * @events: security events
679 * @ssid: source security identifier or %SECSID_WILD
680 * @tsid: target security identifier or %SECSID_WILD
681 * @tclass: target security class
682 * @perms: permissions
684 * Register a callback function for events in the set @events
685 * related to the SID pair (@ssid, @tsid) and
686 * and the permissions @perms, interpreting
687 * @perms based on @tclass. Returns %0 on success or
688 * -%ENOMEM if insufficient memory exists to add the callback.
690 int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
691 u16 tclass, u32 perms,
692 u32 *out_retained),
693 u32 events, u32 ssid, u32 tsid,
694 u16 tclass, u32 perms)
696 struct avc_callback_node *c;
697 int rc = 0;
699 c = kmalloc(sizeof(*c), GFP_ATOMIC);
700 if (!c) {
701 rc = -ENOMEM;
702 goto out;
705 c->callback = callback;
706 c->events = events;
707 c->ssid = ssid;
708 c->tsid = tsid;
709 c->perms = perms;
710 c->next = avc_callbacks;
711 avc_callbacks = c;
712 out:
713 return rc;
716 static inline int avc_sidcmp(u32 x, u32 y)
718 return (x == y || x == SECSID_WILD || y == SECSID_WILD);
722 * avc_update_node Update an AVC entry
723 * @event : Updating event
724 * @perms : Permission mask bits
725 * @ssid,@tsid,@tclass : identifier of an AVC entry
727 * if a valid AVC entry doesn't exist,this function returns -ENOENT.
728 * if kmalloc() called internal returns NULL, this function returns -ENOMEM.
729 * otherwise, this function update the AVC entry. The original AVC-entry object
730 * will release later by RCU.
732 static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass)
734 int hvalue, rc = 0;
735 unsigned long flag;
736 struct avc_node *pos, *node, *orig = NULL;
738 node = avc_alloc_node();
739 if (!node) {
740 rc = -ENOMEM;
741 goto out;
744 /* Lock the target slot */
745 hvalue = avc_hash(ssid, tsid, tclass);
746 spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
748 list_for_each_entry(pos, &avc_cache.slots[hvalue], list){
749 if ( ssid==pos->ae.ssid &&
750 tsid==pos->ae.tsid &&
751 tclass==pos->ae.tclass ){
752 orig = pos;
753 break;
757 if (!orig) {
758 rc = -ENOENT;
759 avc_node_kill(node);
760 goto out_unlock;
764 * Copy and replace original node.
767 avc_node_populate(node, ssid, tsid, tclass, &orig->ae);
769 switch (event) {
770 case AVC_CALLBACK_GRANT:
771 node->ae.avd.allowed |= perms;
772 break;
773 case AVC_CALLBACK_TRY_REVOKE:
774 case AVC_CALLBACK_REVOKE:
775 node->ae.avd.allowed &= ~perms;
776 break;
777 case AVC_CALLBACK_AUDITALLOW_ENABLE:
778 node->ae.avd.auditallow |= perms;
779 break;
780 case AVC_CALLBACK_AUDITALLOW_DISABLE:
781 node->ae.avd.auditallow &= ~perms;
782 break;
783 case AVC_CALLBACK_AUDITDENY_ENABLE:
784 node->ae.avd.auditdeny |= perms;
785 break;
786 case AVC_CALLBACK_AUDITDENY_DISABLE:
787 node->ae.avd.auditdeny &= ~perms;
788 break;
790 avc_node_replace(node, orig);
791 out_unlock:
792 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
793 out:
794 return rc;
798 * avc_ss_reset - Flush the cache and revalidate migrated permissions.
799 * @seqno: policy sequence number
801 int avc_ss_reset(u32 seqno)
803 struct avc_callback_node *c;
804 int i, rc = 0, tmprc;
805 unsigned long flag;
806 struct avc_node *node;
808 for (i = 0; i < AVC_CACHE_SLOTS; i++) {
809 spin_lock_irqsave(&avc_cache.slots_lock[i], flag);
810 list_for_each_entry(node, &avc_cache.slots[i], list)
811 avc_node_delete(node);
812 spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag);
815 for (c = avc_callbacks; c; c = c->next) {
816 if (c->events & AVC_CALLBACK_RESET) {
817 tmprc = c->callback(AVC_CALLBACK_RESET,
818 0, 0, 0, 0, NULL);
819 /* save the first error encountered for the return
820 value and continue processing the callbacks */
821 if (!rc)
822 rc = tmprc;
826 avc_latest_notif_update(seqno, 0);
827 return rc;
831 * avc_has_perm_noaudit - Check permissions but perform no auditing.
832 * @ssid: source security identifier
833 * @tsid: target security identifier
834 * @tclass: target security class
835 * @requested: requested permissions, interpreted based on @tclass
836 * @flags: AVC_STRICT or 0
837 * @avd: access vector decisions
839 * Check the AVC to determine whether the @requested permissions are granted
840 * for the SID pair (@ssid, @tsid), interpreting the permissions
841 * based on @tclass, and call the security server on a cache miss to obtain
842 * a new decision and add it to the cache. Return a copy of the decisions
843 * in @avd. Return %0 if all @requested permissions are granted,
844 * -%EACCES if any permissions are denied, or another -errno upon
845 * other errors. This function is typically called by avc_has_perm(),
846 * but may also be called directly to separate permission checking from
847 * auditing, e.g. in cases where a lock must be held for the check but
848 * should be released for the auditing.
850 int avc_has_perm_noaudit(u32 ssid, u32 tsid,
851 u16 tclass, u32 requested,
852 unsigned flags,
853 struct av_decision *avd)
855 struct avc_node *node;
856 struct avc_entry entry, *p_ae;
857 int rc = 0;
858 u32 denied;
860 rcu_read_lock();
862 node = avc_lookup(ssid, tsid, tclass, requested);
863 if (!node) {
864 rcu_read_unlock();
865 rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd);
866 if (rc)
867 goto out;
868 rcu_read_lock();
869 node = avc_insert(ssid,tsid,tclass,&entry);
872 p_ae = node ? &node->ae : &entry;
874 if (avd)
875 memcpy(avd, &p_ae->avd, sizeof(*avd));
877 denied = requested & ~(p_ae->avd.allowed);
879 if (!requested || denied) {
880 if (selinux_enforcing || (flags & AVC_STRICT))
881 rc = -EACCES;
882 else
883 if (node)
884 avc_update_node(AVC_CALLBACK_GRANT,requested,
885 ssid,tsid,tclass);
888 rcu_read_unlock();
889 out:
890 return rc;
894 * avc_has_perm - Check permissions and perform any appropriate auditing.
895 * @ssid: source security identifier
896 * @tsid: target security identifier
897 * @tclass: target security class
898 * @requested: requested permissions, interpreted based on @tclass
899 * @auditdata: auxiliary audit data
901 * Check the AVC to determine whether the @requested permissions are granted
902 * for the SID pair (@ssid, @tsid), interpreting the permissions
903 * based on @tclass, and call the security server on a cache miss to obtain
904 * a new decision and add it to the cache. Audit the granting or denial of
905 * permissions in accordance with the policy. Return %0 if all @requested
906 * permissions are granted, -%EACCES if any permissions are denied, or
907 * another -errno upon other errors.
909 int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
910 u32 requested, struct avc_audit_data *auditdata)
912 struct av_decision avd;
913 int rc;
915 rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
916 avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
917 return rc;
920 u32 avc_policy_seqno(void)
922 return avc_cache.latest_notif;