blob: 187964e88af1513f79940e025a2353407eff107a [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 }
Stephen Smalleya764ae42007-03-26 13:36:26 -0400220
221 BUG_ON(tclass >= ARRAY_SIZE(class_to_string) || !class_to_string[tclass]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 audit_log_format(ab, " tclass=%s", class_to_string[tclass]);
223}
224
225/**
226 * avc_init - Initialize the AVC.
227 *
228 * Initialize the access vector cache.
229 */
230void __init avc_init(void)
231{
232 int i;
233
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]);
237 }
238 atomic_set(&avc_cache.active_nodes, 0);
239 atomic_set(&avc_cache.lru_hint, 0);
240
241 avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node),
Paul Mundt20c2df82007-07-20 10:11:58 +0900242 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100244 audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245}
246
247int avc_get_hash_stats(char *page)
248{
249 int i, chain_len, max_chain_len, slots_used;
250 struct avc_node *node;
251
252 rcu_read_lock();
253
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;
264 }
265 }
266
267 rcu_read_unlock();
268
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);
273}
274
275static void avc_node_free(struct rcu_head *rhead)
276{
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);
280}
281
282static void avc_node_delete(struct avc_node *node)
283{
284 list_del_rcu(&node->list);
285 call_rcu(&node->rhead, avc_node_free);
286 atomic_dec(&avc_cache.active_nodes);
287}
288
289static void avc_node_kill(struct avc_node *node)
290{
291 kmem_cache_free(avc_node_cachep, node);
292 avc_cache_stats_incr(frees);
293 atomic_dec(&avc_cache.active_nodes);
294}
295
296static void avc_node_replace(struct avc_node *new, struct avc_node *old)
297{
298 list_replace_rcu(&old->list, &new->list);
299 call_rcu(&old->rhead, avc_node_free);
300 atomic_dec(&avc_cache.active_nodes);
301}
302
303static inline int avc_reclaim_node(void)
304{
305 struct avc_node *node;
306 int hvalue, try, ecx;
307 unsigned long flags;
308
309 for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) {
310 hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1);
311
312 if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags))
313 continue;
314
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;
324 }
325 }
326 }
327 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
328 }
329out:
330 return ecx;
331}
332
333static struct avc_node *avc_alloc_node(void)
334{
335 struct avc_node *node;
336
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800337 node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 if (!node)
339 goto out;
340
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 INIT_RCU_HEAD(&node->rhead);
342 INIT_LIST_HEAD(&node->list);
343 atomic_set(&node->ae.used, 1);
344 avc_cache_stats_incr(allocations);
345
346 if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold)
347 avc_reclaim_node();
348
349out:
350 return node;
351}
352
353static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
354{
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));
359}
360
361static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass)
362{
363 struct avc_node *node, *ret = NULL;
364 int hvalue;
365
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;
373 }
374 }
375
376 if (ret == NULL) {
377 /* cache miss */
378 goto out;
379 }
380
381 /* cache hit */
382 if (atomic_read(&ret->ae.used) != 1)
383 atomic_set(&ret->ae.used, 1);
384out:
385 return ret;
386}
387
388/**
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
394 *
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.
401 */
402static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested)
403{
404 struct avc_node *node;
405
406 avc_cache_stats_incr(lookups);
407 node = avc_search_node(ssid, tsid, tclass);
408
409 if (node && ((node->ae.avd.decided & requested) == requested)) {
410 avc_cache_stats_incr(hits);
411 goto out;
412 }
413
414 node = NULL;
415 avc_cache_stats_incr(misses);
416out:
417 return node;
418}
419
420static int avc_latest_notif_update(int seqno, int is_insert)
421{
422 int ret = 0;
423 static DEFINE_SPINLOCK(notif_lock);
424 unsigned long flag;
425
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;
432 }
433 } else {
434 if (seqno > avc_cache.latest_notif)
435 avc_cache.latest_notif = seqno;
436 }
437 spin_unlock_irqrestore(&notif_lock, flag);
438
439 return ret;
440}
441
442/**
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
448 *
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.
458 */
459static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
460{
461 struct avc_node *pos, *node = NULL;
462 int hvalue;
463 unsigned long flag;
464
465 if (avc_latest_notif_update(ae->avd.seqno, 1))
466 goto out;
467
468 node = avc_alloc_node();
469 if (node) {
470 hvalue = avc_hash(ssid, tsid, tclass);
471 avc_node_populate(node, ssid, tsid, tclass, ae);
472
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;
480 }
481 }
482 list_add_rcu(&node->list, &avc_cache.slots[hvalue]);
483found:
484 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
485 }
486out:
487 return node;
488}
489
490static inline void avc_print_ipv6_addr(struct audit_buffer *ab,
Alexey Dobriyanb5bf6c52005-09-03 15:55:17 -0700491 struct in6_addr *addr, __be16 port,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 char *name1, char *name2)
493{
494 if (!ipv6_addr_any(addr))
Joe Perches46b86a22006-01-13 14:29:07 -0800495 audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 if (port)
497 audit_log_format(ab, " %s=%d", name2, ntohs(port));
498}
499
Al Viro87fcd702006-12-04 22:00:55 +0000500static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
Alexey Dobriyanb5bf6c52005-09-03 15:55:17 -0700501 __be16 port, char *name1, char *name2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502{
503 if (addr)
Joe Perches46b86a22006-01-13 14:29:07 -0800504 audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 if (port)
506 audit_log_format(ab, " %s=%d", name2, ntohs(port));
507}
508
509/**
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
518 *
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.
527 */
528void avc_audit(u32 ssid, u32 tsid,
529 u16 tclass, u32 requested,
530 struct av_decision *avd, int result, struct avc_audit_data *a)
531{
David Woodhousecd77b822005-05-19 11:18:24 +0100532 struct task_struct *tsk = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 struct inode *inode = NULL;
534 u32 denied, audited;
535 struct audit_buffer *ab;
536
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;
548 }
549
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100550 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 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 ");
David Woodhousecd77b822005-05-19 11:18:24 +0100556 if (a && a->tsk)
557 tsk = a->tsk;
David Woodhouse7b5d7812005-05-21 16:52:57 +0100558 if (tsk && tsk->pid) {
David Woodhousecd77b822005-05-19 11:18:24 +0100559 audit_log_format(ab, " pid=%d comm=", tsk->pid);
560 audit_log_untrustedstring(ab, tsk->comm);
561 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 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:
Jan Blunck44707fd2008-02-14 19:38:33 -0800571 if (a->u.fs.path.dentry) {
572 struct dentry *dentry = a->u.fs.path.dentry;
573 if (a->u.fs.path.mnt) {
574 audit_log_d_path(ab, "path=",
575 &a->u.fs.path);
Al Viro4259fa02007-06-07 11:13:31 -0400576 } else {
577 audit_log_format(ab, " name=");
578 audit_log_untrustedstring(ab, dentry->d_name.name);
579 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 inode = dentry->d_inode;
581 } else if (a->u.fs.inode) {
582 struct dentry *dentry;
583 inode = a->u.fs.inode;
584 dentry = d_find_alias(inode);
585 if (dentry) {
Stephen Smalley37ca5382005-05-24 21:28:28 +0100586 audit_log_format(ab, " name=");
587 audit_log_untrustedstring(ab, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 dput(dentry);
589 }
590 }
591 if (inode)
Tobias Oed13bddc22007-06-11 08:56:31 -0400592 audit_log_format(ab, " dev=%s ino=%lu",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 inode->i_sb->s_id,
594 inode->i_ino);
595 break;
596 case AVC_AUDIT_DATA_NET:
597 if (a->u.net.sk) {
598 struct sock *sk = a->u.net.sk;
599 struct unix_sock *u;
600 int len = 0;
601 char *p = NULL;
602
603 switch (sk->sk_family) {
604 case AF_INET: {
605 struct inet_sock *inet = inet_sk(sk);
606
607 avc_print_ipv4_addr(ab, inet->rcv_saddr,
608 inet->sport,
609 "laddr", "lport");
610 avc_print_ipv4_addr(ab, inet->daddr,
611 inet->dport,
612 "faddr", "fport");
613 break;
614 }
615 case AF_INET6: {
616 struct inet_sock *inet = inet_sk(sk);
617 struct ipv6_pinfo *inet6 = inet6_sk(sk);
618
619 avc_print_ipv6_addr(ab, &inet6->rcv_saddr,
620 inet->sport,
621 "laddr", "lport");
622 avc_print_ipv6_addr(ab, &inet6->daddr,
623 inet->dport,
624 "faddr", "fport");
625 break;
626 }
627 case AF_UNIX:
628 u = unix_sk(sk);
629 if (u->dentry) {
Jan Blunck44707fd2008-02-14 19:38:33 -0800630 struct path path = {
631 .dentry = u->dentry,
632 .mnt = u->mnt
633 };
Al Viro4259fa02007-06-07 11:13:31 -0400634 audit_log_d_path(ab, "path=",
Jan Blunck44707fd2008-02-14 19:38:33 -0800635 &path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 break;
637 }
638 if (!u->addr)
639 break;
640 len = u->addr->len-sizeof(short);
641 p = &u->addr->name->sun_path[0];
Stephen Smalley37ca5382005-05-24 21:28:28 +0100642 audit_log_format(ab, " path=");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 if (*p)
Stephen Smalley37ca5382005-05-24 21:28:28 +0100644 audit_log_untrustedstring(ab, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 else
Stephen Smalley37ca5382005-05-24 21:28:28 +0100646 audit_log_hex(ab, p, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 break;
648 }
649 }
650
651 switch (a->u.net.family) {
652 case AF_INET:
653 avc_print_ipv4_addr(ab, a->u.net.v4info.saddr,
654 a->u.net.sport,
655 "saddr", "src");
656 avc_print_ipv4_addr(ab, a->u.net.v4info.daddr,
657 a->u.net.dport,
658 "daddr", "dest");
659 break;
660 case AF_INET6:
661 avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr,
662 a->u.net.sport,
663 "saddr", "src");
664 avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr,
665 a->u.net.dport,
666 "daddr", "dest");
667 break;
668 }
Paul Mooreda5645a2008-01-29 08:38:10 -0500669 if (a->u.net.netif > 0) {
670 struct net_device *dev;
671
672 /* NOTE: we always use init's namespace */
673 dev = dev_get_by_index(&init_net,
674 a->u.net.netif);
675 if (dev) {
676 audit_log_format(ab, " netif=%s",
677 dev->name);
678 dev_put(dev);
679 }
680 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 break;
682 }
683 }
684 audit_log_format(ab, " ");
685 avc_dump_query(ab, ssid, tsid, tclass);
686 audit_log_end(ab);
687}
688
689/**
690 * avc_add_callback - Register a callback for security events.
691 * @callback: callback function
692 * @events: security events
693 * @ssid: source security identifier or %SECSID_WILD
694 * @tsid: target security identifier or %SECSID_WILD
695 * @tclass: target security class
696 * @perms: permissions
697 *
698 * Register a callback function for events in the set @events
699 * related to the SID pair (@ssid, @tsid) and
700 * and the permissions @perms, interpreting
701 * @perms based on @tclass. Returns %0 on success or
702 * -%ENOMEM if insufficient memory exists to add the callback.
703 */
704int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
705 u16 tclass, u32 perms,
706 u32 *out_retained),
707 u32 events, u32 ssid, u32 tsid,
708 u16 tclass, u32 perms)
709{
710 struct avc_callback_node *c;
711 int rc = 0;
712
713 c = kmalloc(sizeof(*c), GFP_ATOMIC);
714 if (!c) {
715 rc = -ENOMEM;
716 goto out;
717 }
718
719 c->callback = callback;
720 c->events = events;
721 c->ssid = ssid;
722 c->tsid = tsid;
723 c->perms = perms;
724 c->next = avc_callbacks;
725 avc_callbacks = c;
726out:
727 return rc;
728}
729
730static inline int avc_sidcmp(u32 x, u32 y)
731{
732 return (x == y || x == SECSID_WILD || y == SECSID_WILD);
733}
734
735/**
736 * avc_update_node Update an AVC entry
737 * @event : Updating event
738 * @perms : Permission mask bits
739 * @ssid,@tsid,@tclass : identifier of an AVC entry
740 *
741 * if a valid AVC entry doesn't exist,this function returns -ENOENT.
742 * if kmalloc() called internal returns NULL, this function returns -ENOMEM.
743 * otherwise, this function update the AVC entry. The original AVC-entry object
744 * will release later by RCU.
745 */
746static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass)
747{
748 int hvalue, rc = 0;
749 unsigned long flag;
750 struct avc_node *pos, *node, *orig = NULL;
751
752 node = avc_alloc_node();
753 if (!node) {
754 rc = -ENOMEM;
755 goto out;
756 }
757
758 /* Lock the target slot */
759 hvalue = avc_hash(ssid, tsid, tclass);
760 spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
761
762 list_for_each_entry(pos, &avc_cache.slots[hvalue], list){
763 if ( ssid==pos->ae.ssid &&
764 tsid==pos->ae.tsid &&
765 tclass==pos->ae.tclass ){
766 orig = pos;
767 break;
768 }
769 }
770
771 if (!orig) {
772 rc = -ENOENT;
773 avc_node_kill(node);
774 goto out_unlock;
775 }
776
777 /*
778 * Copy and replace original node.
779 */
780
781 avc_node_populate(node, ssid, tsid, tclass, &orig->ae);
782
783 switch (event) {
784 case AVC_CALLBACK_GRANT:
785 node->ae.avd.allowed |= perms;
786 break;
787 case AVC_CALLBACK_TRY_REVOKE:
788 case AVC_CALLBACK_REVOKE:
789 node->ae.avd.allowed &= ~perms;
790 break;
791 case AVC_CALLBACK_AUDITALLOW_ENABLE:
792 node->ae.avd.auditallow |= perms;
793 break;
794 case AVC_CALLBACK_AUDITALLOW_DISABLE:
795 node->ae.avd.auditallow &= ~perms;
796 break;
797 case AVC_CALLBACK_AUDITDENY_ENABLE:
798 node->ae.avd.auditdeny |= perms;
799 break;
800 case AVC_CALLBACK_AUDITDENY_DISABLE:
801 node->ae.avd.auditdeny &= ~perms;
802 break;
803 }
804 avc_node_replace(node, orig);
805out_unlock:
806 spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
807out:
808 return rc;
809}
810
811/**
812 * avc_ss_reset - Flush the cache and revalidate migrated permissions.
813 * @seqno: policy sequence number
814 */
815int avc_ss_reset(u32 seqno)
816{
817 struct avc_callback_node *c;
Darrel Goeddel376bd9c2006-02-24 15:44:05 -0600818 int i, rc = 0, tmprc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 unsigned long flag;
820 struct avc_node *node;
821
822 for (i = 0; i < AVC_CACHE_SLOTS; i++) {
823 spin_lock_irqsave(&avc_cache.slots_lock[i], flag);
824 list_for_each_entry(node, &avc_cache.slots[i], list)
825 avc_node_delete(node);
826 spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag);
827 }
828
829 for (c = avc_callbacks; c; c = c->next) {
830 if (c->events & AVC_CALLBACK_RESET) {
Darrel Goeddel376bd9c2006-02-24 15:44:05 -0600831 tmprc = c->callback(AVC_CALLBACK_RESET,
832 0, 0, 0, 0, NULL);
833 /* save the first error encountered for the return
834 value and continue processing the callbacks */
835 if (!rc)
836 rc = tmprc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 }
838 }
839
840 avc_latest_notif_update(seqno, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 return rc;
842}
843
844/**
845 * avc_has_perm_noaudit - Check permissions but perform no auditing.
846 * @ssid: source security identifier
847 * @tsid: target security identifier
848 * @tclass: target security class
849 * @requested: requested permissions, interpreted based on @tclass
Stephen Smalley2c3c05d2007-06-07 15:34:10 -0400850 * @flags: AVC_STRICT or 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 * @avd: access vector decisions
852 *
853 * Check the AVC to determine whether the @requested permissions are granted
854 * for the SID pair (@ssid, @tsid), interpreting the permissions
855 * based on @tclass, and call the security server on a cache miss to obtain
856 * a new decision and add it to the cache. Return a copy of the decisions
857 * in @avd. Return %0 if all @requested permissions are granted,
858 * -%EACCES if any permissions are denied, or another -errno upon
859 * other errors. This function is typically called by avc_has_perm(),
860 * but may also be called directly to separate permission checking from
861 * auditing, e.g. in cases where a lock must be held for the check but
862 * should be released for the auditing.
863 */
864int avc_has_perm_noaudit(u32 ssid, u32 tsid,
Stephen Smalley2c3c05d2007-06-07 15:34:10 -0400865 u16 tclass, u32 requested,
866 unsigned flags,
867 struct av_decision *avd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868{
869 struct avc_node *node;
870 struct avc_entry entry, *p_ae;
871 int rc = 0;
872 u32 denied;
873
874 rcu_read_lock();
875
876 node = avc_lookup(ssid, tsid, tclass, requested);
877 if (!node) {
878 rcu_read_unlock();
879 rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd);
880 if (rc)
881 goto out;
882 rcu_read_lock();
883 node = avc_insert(ssid,tsid,tclass,&entry);
884 }
885
886 p_ae = node ? &node->ae : &entry;
887
888 if (avd)
889 memcpy(avd, &p_ae->avd, sizeof(*avd));
890
891 denied = requested & ~(p_ae->avd.allowed);
892
893 if (!requested || denied) {
Stephen Smalley2c3c05d2007-06-07 15:34:10 -0400894 if (selinux_enforcing || (flags & AVC_STRICT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 rc = -EACCES;
896 else
897 if (node)
898 avc_update_node(AVC_CALLBACK_GRANT,requested,
899 ssid,tsid,tclass);
900 }
901
902 rcu_read_unlock();
903out:
904 return rc;
905}
906
907/**
908 * avc_has_perm - Check permissions and perform any appropriate auditing.
909 * @ssid: source security identifier
910 * @tsid: target security identifier
911 * @tclass: target security class
912 * @requested: requested permissions, interpreted based on @tclass
913 * @auditdata: auxiliary audit data
914 *
915 * Check the AVC to determine whether the @requested permissions are granted
916 * for the SID pair (@ssid, @tsid), interpreting the permissions
917 * based on @tclass, and call the security server on a cache miss to obtain
918 * a new decision and add it to the cache. Audit the granting or denial of
919 * permissions in accordance with the policy. Return %0 if all @requested
920 * permissions are granted, -%EACCES if any permissions are denied, or
921 * another -errno upon other errors.
922 */
923int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
924 u32 requested, struct avc_audit_data *auditdata)
925{
926 struct av_decision avd;
927 int rc;
928
Stephen Smalley2c3c05d2007-06-07 15:34:10 -0400929 rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
931 return rc;
932}
Yuichi Nakamura788e7dd2007-09-14 09:27:07 +0900933
934u32 avc_policy_seqno(void)
935{
936 return avc_cache.latest_notif;
937}