blob: da8caf10ef9745b5f222117e9e236960c2f4e643 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Implementation of the kernel access vector cache (AVC).
3 *
4 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com>
8 * Replaced the avc_lock spinlock by RCU.
9 *
10 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
11 *
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.
15 */
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"
34
Chad Sellers5c458992006-11-06 12:38:16 -050035static const struct av_perm_to_string av_perm_to_string[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#define S_(c, v, s) { c, v, s },
37#include "av_perm_to_string.h"
38#undef S_
39};
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041static const char *class_to_string[] = {
42#define S_(s) s,
43#include "class_to_string.h"
44#undef S_
45};
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
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_
54
Chad Sellers5c458992006-11-06 12:38:16 -050055static const struct av_inherit av_inherit[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#define S_(c, i, b) { c, common_##i##_perm_to_string, b },
57#include "av_inherit.h"
58#undef S_
59};
60
Chad Sellers5c458992006-11-06 12:38:16 -050061const 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)
68};
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070#define AVC_CACHE_SLOTS 512
71#define AVC_DEF_CACHE_THRESHOLD 512
72#define AVC_CACHE_RECLAIM 16
73
74#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
75#define avc_cache_stats_incr(field) \
76do { \
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
83
84struct avc_entry {
85 u32 ssid;
86 u32 tsid;
87 u16 tclass;
88 struct av_decision avd;
89 atomic_t used; /* used recently */
90};
91
92struct avc_node {
93 struct avc_entry ae;
94 struct list_head list;
95 struct rcu_head rhead;
96};
97
98struct 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 */
104};
105
106struct 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;
116};
117
118/* Exported via selinufs */
119unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD;
120
121#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
122DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 };
123#endif
124
125static struct avc_cache avc_cache;
126static struct avc_callback_node *avc_callbacks;
Christoph Lametere18b8902006-12-06 20:33:20 -0800127static struct kmem_cache *avc_node_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
130{
131 return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1);
132}
133
134/**
135 * avc_dump_av - Display an access vector in human-readable form.
136 * @tclass: target security class
137 * @av: access vector
138 */
139static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
140{
141 const char **common_pts = NULL;
142 u32 common_base = 0;
143 int i, i2, perm;
144
145 if (av == 0) {
146 audit_log_format(ab, " null");
147 return;
148 }
149
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;
155 }
156 }
157
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;
165 }
166 i++;
167 perm <<= 1;
168 }
169
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;
176 }
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;
181 }
182 }
183 i++;
184 perm <<= 1;
185 }
186
187 if (av)
188 audit_log_format(ab, " 0x%x", av);
189
190 audit_log_format(ab, " }");
191}
192
193/**
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
198 */
199static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass)
200{
201 int rc;
202 char *scontext;
203 u32 scontext_len;
204
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);
211 }
212
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);
219 }
220 audit_log_format(ab, " tclass=%s", class_to_string[tclass]);
221}
222
223/**
224 * avc_init - Initialize the AVC.
225 *
226 * Initialize the access vector cache.
227 */
228void __init avc_init(void)
229{
230 int i;
231
232 for (i = 0; i < AVC_CACHE_SLOTS; i++) {
233 INIT_LIST_HEAD(&avc_cache.slots[i]);
234 spin_lock_init(&avc_cache.slots_lock[i]);
235 }
236 atomic_set(&avc_cache.active_nodes, 0);
237 atomic_set(&avc_cache.lru_hint, 0);
238
239 avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node),
240 0, SLAB_PANIC, NULL, NULL);
241
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100242 audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243}
244
245int avc_get_hash_stats(char *page)
246{
247 int i, chain_len, max_chain_len, slots_used;
248 struct avc_node *node;
249
250 rcu_read_lock();
251
252 slots_used = 0;
253 max_chain_len = 0;
254 for (i = 0; i < AVC_CACHE_SLOTS; i++) {
255 if (!list_empty(&avc_cache.slots[i])) {
256 slots_used++;
257 chain_len = 0;
258 list_for_each_entry_rcu(node, &avc_cache.slots[i], list)
259 chain_len++;
260 if (chain_len > max_chain_len)
261 max_chain_len = chain_len;
262 }
263 }
264
265 rcu_read_unlock();
266
267 return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n"
268 "longest chain: %d\n",
269 atomic_read(&avc_cache.active_nodes),
270 slots_used, AVC_CACHE_SLOTS, max_chain_len);
271}
272
273static void avc_node_free(struct rcu_head *rhead)
274{
275 struct avc_node *node = container_of(rhead, struct avc_node, rhead);
276 kmem_cache_free(avc_node_cachep, node);
277 avc_cache_stats_incr(frees);
278}
279
280static void avc_node_delete(struct avc_node *node)
281{
282 list_del_rcu(&node->list);
283 call_rcu(&node->rhead, avc_node_free);
284 atomic_dec(&avc_cache.active_nodes);
285}
286
287static void avc_node_kill(struct avc_node *node)
288{
289 kmem_cache_free(avc_node_cachep, node);
290 avc_cache_stats_incr(frees);
291 atomic_dec(&avc_cache.active_nodes);
292}
293
294static void avc_node_replace(struct avc_node *new, struct avc_node *old)
295{
296 list_replace_rcu(&old->list, &new->list);
297 call_rcu(&old->rhead, avc_node_free);
298 atomic_dec(&avc_cache.active_nodes);
299}
300
301static inline int avc_reclaim_node(void)
302{
303 struct avc_node *node;
304 int hvalue, try, ecx;
305 unsigned long flags;
306
307 for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) {
308 hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1);
309
310 if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags))
311 continue;
312
313 list_for_each_entry(node, &avc_cache.slots[hvalue], list) {
314 if (atomic_dec_and_test(&node->ae.used)) {
315 /* Recently Unused */
316 avc_node_delete(node);
317 avc_cache_stats_incr(reclaims);
318 ecx++;
319 if (ecx >= AVC_CACHE_RECLAIM) {
320 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
321 goto out;
322 }
323 }
324 }
325 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
326 }
327out:
328 return ecx;
329}
330
331static struct avc_node *avc_alloc_node(void)
332{
333 struct avc_node *node;
334
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800335 node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 if (!node)
337 goto out;
338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 INIT_RCU_HEAD(&node->rhead);
340 INIT_LIST_HEAD(&node->list);
341 atomic_set(&node->ae.used, 1);
342 avc_cache_stats_incr(allocations);
343
344 if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold)
345 avc_reclaim_node();
346
347out:
348 return node;
349}
350
351static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
352{
353 node->ae.ssid = ssid;
354 node->ae.tsid = tsid;
355 node->ae.tclass = tclass;
356 memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd));
357}
358
359static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass)
360{
361 struct avc_node *node, *ret = NULL;
362 int hvalue;
363
364 hvalue = avc_hash(ssid, tsid, tclass);
365 list_for_each_entry_rcu(node, &avc_cache.slots[hvalue], list) {
366 if (ssid == node->ae.ssid &&
367 tclass == node->ae.tclass &&
368 tsid == node->ae.tsid) {
369 ret = node;
370 break;
371 }
372 }
373
374 if (ret == NULL) {
375 /* cache miss */
376 goto out;
377 }
378
379 /* cache hit */
380 if (atomic_read(&ret->ae.used) != 1)
381 atomic_set(&ret->ae.used, 1);
382out:
383 return ret;
384}
385
386/**
387 * avc_lookup - Look up an AVC entry.
388 * @ssid: source security identifier
389 * @tsid: target security identifier
390 * @tclass: target security class
391 * @requested: requested permissions, interpreted based on @tclass
392 *
393 * Look up an AVC entry that is valid for the
394 * @requested permissions between the SID pair
395 * (@ssid, @tsid), interpreting the permissions
396 * based on @tclass. If a valid AVC entry exists,
397 * then this function return the avc_node.
398 * Otherwise, this function returns NULL.
399 */
400static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested)
401{
402 struct avc_node *node;
403
404 avc_cache_stats_incr(lookups);
405 node = avc_search_node(ssid, tsid, tclass);
406
407 if (node && ((node->ae.avd.decided & requested) == requested)) {
408 avc_cache_stats_incr(hits);
409 goto out;
410 }
411
412 node = NULL;
413 avc_cache_stats_incr(misses);
414out:
415 return node;
416}
417
418static int avc_latest_notif_update(int seqno, int is_insert)
419{
420 int ret = 0;
421 static DEFINE_SPINLOCK(notif_lock);
422 unsigned long flag;
423
424 spin_lock_irqsave(&notif_lock, flag);
425 if (is_insert) {
426 if (seqno < avc_cache.latest_notif) {
427 printk(KERN_WARNING "avc: seqno %d < latest_notif %d\n",
428 seqno, avc_cache.latest_notif);
429 ret = -EAGAIN;
430 }
431 } else {
432 if (seqno > avc_cache.latest_notif)
433 avc_cache.latest_notif = seqno;
434 }
435 spin_unlock_irqrestore(&notif_lock, flag);
436
437 return ret;
438}
439
440/**
441 * avc_insert - Insert an AVC entry.
442 * @ssid: source security identifier
443 * @tsid: target security identifier
444 * @tclass: target security class
445 * @ae: AVC entry
446 *
447 * Insert an AVC entry for the SID pair
448 * (@ssid, @tsid) and class @tclass.
449 * The access vectors and the sequence number are
450 * normally provided by the security server in
451 * response to a security_compute_av() call. If the
452 * sequence number @ae->avd.seqno is not less than the latest
453 * revocation notification, then the function copies
454 * the access vectors into a cache entry, returns
455 * avc_node inserted. Otherwise, this function returns NULL.
456 */
457static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
458{
459 struct avc_node *pos, *node = NULL;
460 int hvalue;
461 unsigned long flag;
462
463 if (avc_latest_notif_update(ae->avd.seqno, 1))
464 goto out;
465
466 node = avc_alloc_node();
467 if (node) {
468 hvalue = avc_hash(ssid, tsid, tclass);
469 avc_node_populate(node, ssid, tsid, tclass, ae);
470
471 spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
472 list_for_each_entry(pos, &avc_cache.slots[hvalue], list) {
473 if (pos->ae.ssid == ssid &&
474 pos->ae.tsid == tsid &&
475 pos->ae.tclass == tclass) {
476 avc_node_replace(node, pos);
477 goto found;
478 }
479 }
480 list_add_rcu(&node->list, &avc_cache.slots[hvalue]);
481found:
482 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
483 }
484out:
485 return node;
486}
487
488static inline void avc_print_ipv6_addr(struct audit_buffer *ab,
Alexey Dobriyanb5bf6c52005-09-03 15:55:17 -0700489 struct in6_addr *addr, __be16 port,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 char *name1, char *name2)
491{
492 if (!ipv6_addr_any(addr))
Joe Perches46b86a22006-01-13 14:29:07 -0800493 audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 if (port)
495 audit_log_format(ab, " %s=%d", name2, ntohs(port));
496}
497
Al Viro87fcd702006-12-04 22:00:55 +0000498static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
Alexey Dobriyanb5bf6c52005-09-03 15:55:17 -0700499 __be16 port, char *name1, char *name2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500{
501 if (addr)
Joe Perches46b86a22006-01-13 14:29:07 -0800502 audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 if (port)
504 audit_log_format(ab, " %s=%d", name2, ntohs(port));
505}
506
507/**
508 * avc_audit - Audit the granting or denial of permissions.
509 * @ssid: source security identifier
510 * @tsid: target security identifier
511 * @tclass: target security class
512 * @requested: requested permissions
513 * @avd: access vector decisions
514 * @result: result from avc_has_perm_noaudit
515 * @a: auxiliary audit data
516 *
517 * Audit the granting or denial of permissions in accordance
518 * with the policy. This function is typically called by
519 * avc_has_perm() after a permission check, but can also be
520 * called directly by callers who use avc_has_perm_noaudit()
521 * in order to separate the permission check from the auditing.
522 * For example, this separation is useful when the permission check must
523 * be performed under a lock, to allow the lock to be released
524 * before calling the auditing code.
525 */
526void avc_audit(u32 ssid, u32 tsid,
527 u16 tclass, u32 requested,
528 struct av_decision *avd, int result, struct avc_audit_data *a)
529{
David Woodhousecd77b822005-05-19 11:18:24 +0100530 struct task_struct *tsk = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 struct inode *inode = NULL;
532 u32 denied, audited;
533 struct audit_buffer *ab;
534
535 denied = requested & ~avd->allowed;
536 if (denied) {
537 audited = denied;
538 if (!(audited & avd->auditdeny))
539 return;
540 } else if (result) {
541 audited = denied = requested;
542 } else {
543 audited = requested;
544 if (!(audited & avd->auditallow))
545 return;
546 }
547
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100548 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 if (!ab)
550 return; /* audit_panic has been called */
551 audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted");
552 avc_dump_av(ab, tclass,audited);
553 audit_log_format(ab, " for ");
David Woodhousecd77b822005-05-19 11:18:24 +0100554 if (a && a->tsk)
555 tsk = a->tsk;
David Woodhouse7b5d7812005-05-21 16:52:57 +0100556 if (tsk && tsk->pid) {
David Woodhousecd77b822005-05-19 11:18:24 +0100557 audit_log_format(ab, " pid=%d comm=", tsk->pid);
558 audit_log_untrustedstring(ab, tsk->comm);
559 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 if (a) {
561 switch (a->type) {
562 case AVC_AUDIT_DATA_IPC:
563 audit_log_format(ab, " key=%d", a->u.ipc_id);
564 break;
565 case AVC_AUDIT_DATA_CAP:
566 audit_log_format(ab, " capability=%d", a->u.cap);
567 break;
568 case AVC_AUDIT_DATA_FS:
569 if (a->u.fs.dentry) {
570 struct dentry *dentry = a->u.fs.dentry;
Stephen Smalley01116102005-05-21 00:15:52 +0100571 if (a->u.fs.mnt)
572 audit_avc_path(dentry, a->u.fs.mnt);
Stephen Smalley37ca5382005-05-24 21:28:28 +0100573 audit_log_format(ab, " name=");
574 audit_log_untrustedstring(ab, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 inode = dentry->d_inode;
576 } else if (a->u.fs.inode) {
577 struct dentry *dentry;
578 inode = a->u.fs.inode;
579 dentry = d_find_alias(inode);
580 if (dentry) {
Stephen Smalley37ca5382005-05-24 21:28:28 +0100581 audit_log_format(ab, " name=");
582 audit_log_untrustedstring(ab, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 dput(dentry);
584 }
585 }
586 if (inode)
587 audit_log_format(ab, " dev=%s ino=%ld",
588 inode->i_sb->s_id,
589 inode->i_ino);
590 break;
591 case AVC_AUDIT_DATA_NET:
592 if (a->u.net.sk) {
593 struct sock *sk = a->u.net.sk;
594 struct unix_sock *u;
595 int len = 0;
596 char *p = NULL;
597
598 switch (sk->sk_family) {
599 case AF_INET: {
600 struct inet_sock *inet = inet_sk(sk);
601
602 avc_print_ipv4_addr(ab, inet->rcv_saddr,
603 inet->sport,
604 "laddr", "lport");
605 avc_print_ipv4_addr(ab, inet->daddr,
606 inet->dport,
607 "faddr", "fport");
608 break;
609 }
610 case AF_INET6: {
611 struct inet_sock *inet = inet_sk(sk);
612 struct ipv6_pinfo *inet6 = inet6_sk(sk);
613
614 avc_print_ipv6_addr(ab, &inet6->rcv_saddr,
615 inet->sport,
616 "laddr", "lport");
617 avc_print_ipv6_addr(ab, &inet6->daddr,
618 inet->dport,
619 "faddr", "fport");
620 break;
621 }
622 case AF_UNIX:
623 u = unix_sk(sk);
624 if (u->dentry) {
Stephen Smalley01116102005-05-21 00:15:52 +0100625 audit_avc_path(u->dentry, u->mnt);
Stephen Smalley37ca5382005-05-24 21:28:28 +0100626 audit_log_format(ab, " name=");
627 audit_log_untrustedstring(ab, u->dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 break;
629 }
630 if (!u->addr)
631 break;
632 len = u->addr->len-sizeof(short);
633 p = &u->addr->name->sun_path[0];
Stephen Smalley37ca5382005-05-24 21:28:28 +0100634 audit_log_format(ab, " path=");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 if (*p)
Stephen Smalley37ca5382005-05-24 21:28:28 +0100636 audit_log_untrustedstring(ab, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 else
Stephen Smalley37ca5382005-05-24 21:28:28 +0100638 audit_log_hex(ab, p, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 break;
640 }
641 }
642
643 switch (a->u.net.family) {
644 case AF_INET:
645 avc_print_ipv4_addr(ab, a->u.net.v4info.saddr,
646 a->u.net.sport,
647 "saddr", "src");
648 avc_print_ipv4_addr(ab, a->u.net.v4info.daddr,
649 a->u.net.dport,
650 "daddr", "dest");
651 break;
652 case AF_INET6:
653 avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr,
654 a->u.net.sport,
655 "saddr", "src");
656 avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr,
657 a->u.net.dport,
658 "daddr", "dest");
659 break;
660 }
661 if (a->u.net.netif)
662 audit_log_format(ab, " netif=%s",
663 a->u.net.netif);
664 break;
665 }
666 }
667 audit_log_format(ab, " ");
668 avc_dump_query(ab, ssid, tsid, tclass);
669 audit_log_end(ab);
670}
671
672/**
673 * avc_add_callback - Register a callback for security events.
674 * @callback: callback function
675 * @events: security events
676 * @ssid: source security identifier or %SECSID_WILD
677 * @tsid: target security identifier or %SECSID_WILD
678 * @tclass: target security class
679 * @perms: permissions
680 *
681 * Register a callback function for events in the set @events
682 * related to the SID pair (@ssid, @tsid) and
683 * and the permissions @perms, interpreting
684 * @perms based on @tclass. Returns %0 on success or
685 * -%ENOMEM if insufficient memory exists to add the callback.
686 */
687int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
688 u16 tclass, u32 perms,
689 u32 *out_retained),
690 u32 events, u32 ssid, u32 tsid,
691 u16 tclass, u32 perms)
692{
693 struct avc_callback_node *c;
694 int rc = 0;
695
696 c = kmalloc(sizeof(*c), GFP_ATOMIC);
697 if (!c) {
698 rc = -ENOMEM;
699 goto out;
700 }
701
702 c->callback = callback;
703 c->events = events;
704 c->ssid = ssid;
705 c->tsid = tsid;
706 c->perms = perms;
707 c->next = avc_callbacks;
708 avc_callbacks = c;
709out:
710 return rc;
711}
712
713static inline int avc_sidcmp(u32 x, u32 y)
714{
715 return (x == y || x == SECSID_WILD || y == SECSID_WILD);
716}
717
718/**
719 * avc_update_node Update an AVC entry
720 * @event : Updating event
721 * @perms : Permission mask bits
722 * @ssid,@tsid,@tclass : identifier of an AVC entry
723 *
724 * if a valid AVC entry doesn't exist,this function returns -ENOENT.
725 * if kmalloc() called internal returns NULL, this function returns -ENOMEM.
726 * otherwise, this function update the AVC entry. The original AVC-entry object
727 * will release later by RCU.
728 */
729static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass)
730{
731 int hvalue, rc = 0;
732 unsigned long flag;
733 struct avc_node *pos, *node, *orig = NULL;
734
735 node = avc_alloc_node();
736 if (!node) {
737 rc = -ENOMEM;
738 goto out;
739 }
740
741 /* Lock the target slot */
742 hvalue = avc_hash(ssid, tsid, tclass);
743 spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
744
745 list_for_each_entry(pos, &avc_cache.slots[hvalue], list){
746 if ( ssid==pos->ae.ssid &&
747 tsid==pos->ae.tsid &&
748 tclass==pos->ae.tclass ){
749 orig = pos;
750 break;
751 }
752 }
753
754 if (!orig) {
755 rc = -ENOENT;
756 avc_node_kill(node);
757 goto out_unlock;
758 }
759
760 /*
761 * Copy and replace original node.
762 */
763
764 avc_node_populate(node, ssid, tsid, tclass, &orig->ae);
765
766 switch (event) {
767 case AVC_CALLBACK_GRANT:
768 node->ae.avd.allowed |= perms;
769 break;
770 case AVC_CALLBACK_TRY_REVOKE:
771 case AVC_CALLBACK_REVOKE:
772 node->ae.avd.allowed &= ~perms;
773 break;
774 case AVC_CALLBACK_AUDITALLOW_ENABLE:
775 node->ae.avd.auditallow |= perms;
776 break;
777 case AVC_CALLBACK_AUDITALLOW_DISABLE:
778 node->ae.avd.auditallow &= ~perms;
779 break;
780 case AVC_CALLBACK_AUDITDENY_ENABLE:
781 node->ae.avd.auditdeny |= perms;
782 break;
783 case AVC_CALLBACK_AUDITDENY_DISABLE:
784 node->ae.avd.auditdeny &= ~perms;
785 break;
786 }
787 avc_node_replace(node, orig);
788out_unlock:
789 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
790out:
791 return rc;
792}
793
794/**
795 * avc_ss_reset - Flush the cache and revalidate migrated permissions.
796 * @seqno: policy sequence number
797 */
798int avc_ss_reset(u32 seqno)
799{
800 struct avc_callback_node *c;
Darrel Goeddel376bd9c2006-02-24 15:44:05 -0600801 int i, rc = 0, tmprc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 unsigned long flag;
803 struct avc_node *node;
804
805 for (i = 0; i < AVC_CACHE_SLOTS; i++) {
806 spin_lock_irqsave(&avc_cache.slots_lock[i], flag);
807 list_for_each_entry(node, &avc_cache.slots[i], list)
808 avc_node_delete(node);
809 spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag);
810 }
811
812 for (c = avc_callbacks; c; c = c->next) {
813 if (c->events & AVC_CALLBACK_RESET) {
Darrel Goeddel376bd9c2006-02-24 15:44:05 -0600814 tmprc = c->callback(AVC_CALLBACK_RESET,
815 0, 0, 0, 0, NULL);
816 /* save the first error encountered for the return
817 value and continue processing the callbacks */
818 if (!rc)
819 rc = tmprc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 }
821 }
822
823 avc_latest_notif_update(seqno, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824 return rc;
825}
826
827/**
828 * avc_has_perm_noaudit - Check permissions but perform no auditing.
829 * @ssid: source security identifier
830 * @tsid: target security identifier
831 * @tclass: target security class
832 * @requested: requested permissions, interpreted based on @tclass
833 * @avd: access vector decisions
834 *
835 * Check the AVC to determine whether the @requested permissions are granted
836 * for the SID pair (@ssid, @tsid), interpreting the permissions
837 * based on @tclass, and call the security server on a cache miss to obtain
838 * a new decision and add it to the cache. Return a copy of the decisions
839 * in @avd. Return %0 if all @requested permissions are granted,
840 * -%EACCES if any permissions are denied, or another -errno upon
841 * other errors. This function is typically called by avc_has_perm(),
842 * but may also be called directly to separate permission checking from
843 * auditing, e.g. in cases where a lock must be held for the check but
844 * should be released for the auditing.
845 */
846int avc_has_perm_noaudit(u32 ssid, u32 tsid,
847 u16 tclass, u32 requested,
848 struct av_decision *avd)
849{
850 struct avc_node *node;
851 struct avc_entry entry, *p_ae;
852 int rc = 0;
853 u32 denied;
854
855 rcu_read_lock();
856
857 node = avc_lookup(ssid, tsid, tclass, requested);
858 if (!node) {
859 rcu_read_unlock();
860 rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd);
861 if (rc)
862 goto out;
863 rcu_read_lock();
864 node = avc_insert(ssid,tsid,tclass,&entry);
865 }
866
867 p_ae = node ? &node->ae : &entry;
868
869 if (avd)
870 memcpy(avd, &p_ae->avd, sizeof(*avd));
871
872 denied = requested & ~(p_ae->avd.allowed);
873
874 if (!requested || denied) {
875 if (selinux_enforcing)
876 rc = -EACCES;
877 else
878 if (node)
879 avc_update_node(AVC_CALLBACK_GRANT,requested,
880 ssid,tsid,tclass);
881 }
882
883 rcu_read_unlock();
884out:
885 return rc;
886}
887
888/**
889 * avc_has_perm - Check permissions and perform any appropriate auditing.
890 * @ssid: source security identifier
891 * @tsid: target security identifier
892 * @tclass: target security class
893 * @requested: requested permissions, interpreted based on @tclass
894 * @auditdata: auxiliary audit data
895 *
896 * Check the AVC to determine whether the @requested permissions are granted
897 * for the SID pair (@ssid, @tsid), interpreting the permissions
898 * based on @tclass, and call the security server on a cache miss to obtain
899 * a new decision and add it to the cache. Audit the granting or denial of
900 * permissions in accordance with the policy. Return %0 if all @requested
901 * permissions are granted, -%EACCES if any permissions are denied, or
902 * another -errno upon other errors.
903 */
904int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
905 u32 requested, struct avc_audit_data *auditdata)
906{
907 struct av_decision avd;
908 int rc;
909
910 rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, &avd);
911 avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
912 return rc;
913}