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1da177e4 LT |
1 | /* |
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 | ||
35 | static const struct av_perm_to_string | |
36 | { | |
37 | u16 tclass; | |
38 | u32 value; | |
39 | const char *name; | |
40 | } av_perm_to_string[] = { | |
41 | #define S_(c, v, s) { c, v, s }, | |
42 | #include "av_perm_to_string.h" | |
43 | #undef S_ | |
44 | }; | |
45 | ||
1da177e4 LT |
46 | static const char *class_to_string[] = { |
47 | #define S_(s) s, | |
48 | #include "class_to_string.h" | |
49 | #undef S_ | |
50 | }; | |
1da177e4 LT |
51 | |
52 | #define TB_(s) static const char * s [] = { | |
53 | #define TE_(s) }; | |
54 | #define S_(s) s, | |
55 | #include "common_perm_to_string.h" | |
56 | #undef TB_ | |
57 | #undef TE_ | |
58 | #undef S_ | |
59 | ||
60 | static const struct av_inherit | |
61 | { | |
62 | u16 tclass; | |
63 | const char **common_pts; | |
64 | u32 common_base; | |
65 | } av_inherit[] = { | |
66 | #define S_(c, i, b) { c, common_##i##_perm_to_string, b }, | |
67 | #include "av_inherit.h" | |
68 | #undef S_ | |
69 | }; | |
70 | ||
71 | #define AVC_CACHE_SLOTS 512 | |
72 | #define AVC_DEF_CACHE_THRESHOLD 512 | |
73 | #define AVC_CACHE_RECLAIM 16 | |
74 | ||
75 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS | |
76 | #define avc_cache_stats_incr(field) \ | |
77 | do { \ | |
78 | per_cpu(avc_cache_stats, get_cpu()).field++; \ | |
79 | put_cpu(); \ | |
80 | } while (0) | |
81 | #else | |
82 | #define avc_cache_stats_incr(field) do {} while (0) | |
83 | #endif | |
84 | ||
85 | struct avc_entry { | |
86 | u32 ssid; | |
87 | u32 tsid; | |
88 | u16 tclass; | |
89 | struct av_decision avd; | |
90 | atomic_t used; /* used recently */ | |
91 | }; | |
92 | ||
93 | struct avc_node { | |
94 | struct avc_entry ae; | |
95 | struct list_head list; | |
96 | struct rcu_head rhead; | |
97 | }; | |
98 | ||
99 | struct avc_cache { | |
100 | struct list_head slots[AVC_CACHE_SLOTS]; | |
101 | spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ | |
102 | atomic_t lru_hint; /* LRU hint for reclaim scan */ | |
103 | atomic_t active_nodes; | |
104 | u32 latest_notif; /* latest revocation notification */ | |
105 | }; | |
106 | ||
107 | struct avc_callback_node { | |
108 | int (*callback) (u32 event, u32 ssid, u32 tsid, | |
109 | u16 tclass, u32 perms, | |
110 | u32 *out_retained); | |
111 | u32 events; | |
112 | u32 ssid; | |
113 | u32 tsid; | |
114 | u16 tclass; | |
115 | u32 perms; | |
116 | struct avc_callback_node *next; | |
117 | }; | |
118 | ||
119 | /* Exported via selinufs */ | |
120 | unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; | |
121 | ||
122 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS | |
123 | DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; | |
124 | #endif | |
125 | ||
126 | static struct avc_cache avc_cache; | |
127 | static struct avc_callback_node *avc_callbacks; | |
128 | static kmem_cache_t *avc_node_cachep; | |
129 | ||
130 | static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass) | |
131 | { | |
132 | return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1); | |
133 | } | |
134 | ||
135 | /** | |
136 | * avc_dump_av - Display an access vector in human-readable form. | |
137 | * @tclass: target security class | |
138 | * @av: access vector | |
139 | */ | |
140 | static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av) | |
141 | { | |
142 | const char **common_pts = NULL; | |
143 | u32 common_base = 0; | |
144 | int i, i2, perm; | |
145 | ||
146 | if (av == 0) { | |
147 | audit_log_format(ab, " null"); | |
148 | return; | |
149 | } | |
150 | ||
151 | for (i = 0; i < ARRAY_SIZE(av_inherit); i++) { | |
152 | if (av_inherit[i].tclass == tclass) { | |
153 | common_pts = av_inherit[i].common_pts; | |
154 | common_base = av_inherit[i].common_base; | |
155 | break; | |
156 | } | |
157 | } | |
158 | ||
159 | audit_log_format(ab, " {"); | |
160 | i = 0; | |
161 | perm = 1; | |
162 | while (perm < common_base) { | |
163 | if (perm & av) { | |
164 | audit_log_format(ab, " %s", common_pts[i]); | |
165 | av &= ~perm; | |
166 | } | |
167 | i++; | |
168 | perm <<= 1; | |
169 | } | |
170 | ||
171 | while (i < sizeof(av) * 8) { | |
172 | if (perm & av) { | |
173 | for (i2 = 0; i2 < ARRAY_SIZE(av_perm_to_string); i2++) { | |
174 | if ((av_perm_to_string[i2].tclass == tclass) && | |
175 | (av_perm_to_string[i2].value == perm)) | |
176 | break; | |
177 | } | |
178 | if (i2 < ARRAY_SIZE(av_perm_to_string)) { | |
179 | audit_log_format(ab, " %s", | |
180 | av_perm_to_string[i2].name); | |
181 | av &= ~perm; | |
182 | } | |
183 | } | |
184 | i++; | |
185 | perm <<= 1; | |
186 | } | |
187 | ||
188 | if (av) | |
189 | audit_log_format(ab, " 0x%x", av); | |
190 | ||
191 | audit_log_format(ab, " }"); | |
192 | } | |
193 | ||
194 | /** | |
195 | * avc_dump_query - Display a SID pair and a class in human-readable form. | |
196 | * @ssid: source security identifier | |
197 | * @tsid: target security identifier | |
198 | * @tclass: target security class | |
199 | */ | |
200 | static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass) | |
201 | { | |
202 | int rc; | |
203 | char *scontext; | |
204 | u32 scontext_len; | |
205 | ||
206 | rc = security_sid_to_context(ssid, &scontext, &scontext_len); | |
207 | if (rc) | |
208 | audit_log_format(ab, "ssid=%d", ssid); | |
209 | else { | |
210 | audit_log_format(ab, "scontext=%s", scontext); | |
211 | kfree(scontext); | |
212 | } | |
213 | ||
214 | rc = security_sid_to_context(tsid, &scontext, &scontext_len); | |
215 | if (rc) | |
216 | audit_log_format(ab, " tsid=%d", tsid); | |
217 | else { | |
218 | audit_log_format(ab, " tcontext=%s", scontext); | |
219 | kfree(scontext); | |
220 | } | |
221 | audit_log_format(ab, " tclass=%s", class_to_string[tclass]); | |
222 | } | |
223 | ||
224 | /** | |
225 | * avc_init - Initialize the AVC. | |
226 | * | |
227 | * Initialize the access vector cache. | |
228 | */ | |
229 | void __init avc_init(void) | |
230 | { | |
231 | int i; | |
232 | ||
233 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
234 | INIT_LIST_HEAD(&avc_cache.slots[i]); | |
235 | spin_lock_init(&avc_cache.slots_lock[i]); | |
236 | } | |
237 | atomic_set(&avc_cache.active_nodes, 0); | |
238 | atomic_set(&avc_cache.lru_hint, 0); | |
239 | ||
240 | avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), | |
241 | 0, SLAB_PANIC, NULL, NULL); | |
242 | ||
9ad9ad38 | 243 | audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n"); |
1da177e4 LT |
244 | } |
245 | ||
246 | int avc_get_hash_stats(char *page) | |
247 | { | |
248 | int i, chain_len, max_chain_len, slots_used; | |
249 | struct avc_node *node; | |
250 | ||
251 | rcu_read_lock(); | |
252 | ||
253 | slots_used = 0; | |
254 | max_chain_len = 0; | |
255 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
256 | if (!list_empty(&avc_cache.slots[i])) { | |
257 | slots_used++; | |
258 | chain_len = 0; | |
259 | list_for_each_entry_rcu(node, &avc_cache.slots[i], list) | |
260 | chain_len++; | |
261 | if (chain_len > max_chain_len) | |
262 | max_chain_len = chain_len; | |
263 | } | |
264 | } | |
265 | ||
266 | rcu_read_unlock(); | |
267 | ||
268 | return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" | |
269 | "longest chain: %d\n", | |
270 | atomic_read(&avc_cache.active_nodes), | |
271 | slots_used, AVC_CACHE_SLOTS, max_chain_len); | |
272 | } | |
273 | ||
274 | static void avc_node_free(struct rcu_head *rhead) | |
275 | { | |
276 | struct avc_node *node = container_of(rhead, struct avc_node, rhead); | |
277 | kmem_cache_free(avc_node_cachep, node); | |
278 | avc_cache_stats_incr(frees); | |
279 | } | |
280 | ||
281 | static void avc_node_delete(struct avc_node *node) | |
282 | { | |
283 | list_del_rcu(&node->list); | |
284 | call_rcu(&node->rhead, avc_node_free); | |
285 | atomic_dec(&avc_cache.active_nodes); | |
286 | } | |
287 | ||
288 | static void avc_node_kill(struct avc_node *node) | |
289 | { | |
290 | kmem_cache_free(avc_node_cachep, node); | |
291 | avc_cache_stats_incr(frees); | |
292 | atomic_dec(&avc_cache.active_nodes); | |
293 | } | |
294 | ||
295 | static void avc_node_replace(struct avc_node *new, struct avc_node *old) | |
296 | { | |
297 | list_replace_rcu(&old->list, &new->list); | |
298 | call_rcu(&old->rhead, avc_node_free); | |
299 | atomic_dec(&avc_cache.active_nodes); | |
300 | } | |
301 | ||
302 | static inline int avc_reclaim_node(void) | |
303 | { | |
304 | struct avc_node *node; | |
305 | int hvalue, try, ecx; | |
306 | unsigned long flags; | |
307 | ||
308 | for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) { | |
309 | hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1); | |
310 | ||
311 | if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags)) | |
312 | continue; | |
313 | ||
314 | list_for_each_entry(node, &avc_cache.slots[hvalue], list) { | |
315 | if (atomic_dec_and_test(&node->ae.used)) { | |
316 | /* Recently Unused */ | |
317 | avc_node_delete(node); | |
318 | avc_cache_stats_incr(reclaims); | |
319 | ecx++; | |
320 | if (ecx >= AVC_CACHE_RECLAIM) { | |
321 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); | |
322 | goto out; | |
323 | } | |
324 | } | |
325 | } | |
326 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); | |
327 | } | |
328 | out: | |
329 | return ecx; | |
330 | } | |
331 | ||
332 | static struct avc_node *avc_alloc_node(void) | |
333 | { | |
334 | struct avc_node *node; | |
335 | ||
336 | node = kmem_cache_alloc(avc_node_cachep, SLAB_ATOMIC); | |
337 | if (!node) | |
338 | goto out; | |
339 | ||
340 | memset(node, 0, sizeof(*node)); | |
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); | |
345 | ||
346 | if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold) | |
347 | avc_reclaim_node(); | |
348 | ||
349 | out: | |
350 | return node; | |
351 | } | |
352 | ||
353 | static 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 | ||
361 | static 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); | |
384 | out: | |
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 | */ | |
402 | static 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); | |
416 | out: | |
417 | return node; | |
418 | } | |
419 | ||
420 | static 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(¬if_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(¬if_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 | */ | |
459 | static 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]); | |
483 | found: | |
484 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
485 | } | |
486 | out: | |
487 | return node; | |
488 | } | |
489 | ||
490 | static inline void avc_print_ipv6_addr(struct audit_buffer *ab, | |
b5bf6c55 | 491 | struct in6_addr *addr, __be16 port, |
1da177e4 LT |
492 | char *name1, char *name2) |
493 | { | |
494 | if (!ipv6_addr_any(addr)) | |
46b86a2d | 495 | audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr)); |
1da177e4 LT |
496 | if (port) |
497 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
498 | } | |
499 | ||
500 | static inline void avc_print_ipv4_addr(struct audit_buffer *ab, u32 addr, | |
b5bf6c55 | 501 | __be16 port, char *name1, char *name2) |
1da177e4 LT |
502 | { |
503 | if (addr) | |
46b86a2d | 504 | audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr)); |
1da177e4 LT |
505 | 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 | */ | |
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) | |
531 | { | |
cd77b821 | 532 | struct task_struct *tsk = current; |
1da177e4 LT |
533 | 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 | ||
9ad9ad38 | 550 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); |
1da177e4 LT |
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 "); | |
cd77b821 DW |
556 | if (a && a->tsk) |
557 | tsk = a->tsk; | |
7b5d781c | 558 | if (tsk && tsk->pid) { |
cd77b821 DW |
559 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
560 | audit_log_untrustedstring(ab, tsk->comm); | |
561 | } | |
1da177e4 LT |
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; | |
01116105 SS |
573 | if (a->u.fs.mnt) |
574 | audit_avc_path(dentry, a->u.fs.mnt); | |
37ca5389 SS |
575 | audit_log_format(ab, " name="); |
576 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
1da177e4 LT |
577 | inode = dentry->d_inode; |
578 | } else if (a->u.fs.inode) { | |
579 | struct dentry *dentry; | |
580 | inode = a->u.fs.inode; | |
581 | dentry = d_find_alias(inode); | |
582 | if (dentry) { | |
37ca5389 SS |
583 | audit_log_format(ab, " name="); |
584 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
1da177e4 LT |
585 | dput(dentry); |
586 | } | |
587 | } | |
588 | if (inode) | |
589 | audit_log_format(ab, " dev=%s ino=%ld", | |
590 | inode->i_sb->s_id, | |
591 | inode->i_ino); | |
592 | break; | |
593 | case AVC_AUDIT_DATA_NET: | |
594 | if (a->u.net.sk) { | |
595 | struct sock *sk = a->u.net.sk; | |
596 | struct unix_sock *u; | |
597 | int len = 0; | |
598 | char *p = NULL; | |
599 | ||
600 | switch (sk->sk_family) { | |
601 | case AF_INET: { | |
602 | struct inet_sock *inet = inet_sk(sk); | |
603 | ||
604 | avc_print_ipv4_addr(ab, inet->rcv_saddr, | |
605 | inet->sport, | |
606 | "laddr", "lport"); | |
607 | avc_print_ipv4_addr(ab, inet->daddr, | |
608 | inet->dport, | |
609 | "faddr", "fport"); | |
610 | break; | |
611 | } | |
612 | case AF_INET6: { | |
613 | struct inet_sock *inet = inet_sk(sk); | |
614 | struct ipv6_pinfo *inet6 = inet6_sk(sk); | |
615 | ||
616 | avc_print_ipv6_addr(ab, &inet6->rcv_saddr, | |
617 | inet->sport, | |
618 | "laddr", "lport"); | |
619 | avc_print_ipv6_addr(ab, &inet6->daddr, | |
620 | inet->dport, | |
621 | "faddr", "fport"); | |
622 | break; | |
623 | } | |
624 | case AF_UNIX: | |
625 | u = unix_sk(sk); | |
626 | if (u->dentry) { | |
01116105 | 627 | audit_avc_path(u->dentry, u->mnt); |
37ca5389 SS |
628 | audit_log_format(ab, " name="); |
629 | audit_log_untrustedstring(ab, u->dentry->d_name.name); | |
1da177e4 LT |
630 | break; |
631 | } | |
632 | if (!u->addr) | |
633 | break; | |
634 | len = u->addr->len-sizeof(short); | |
635 | p = &u->addr->name->sun_path[0]; | |
37ca5389 | 636 | audit_log_format(ab, " path="); |
1da177e4 | 637 | if (*p) |
37ca5389 | 638 | audit_log_untrustedstring(ab, p); |
1da177e4 | 639 | else |
37ca5389 | 640 | audit_log_hex(ab, p, len); |
1da177e4 LT |
641 | break; |
642 | } | |
643 | } | |
644 | ||
645 | switch (a->u.net.family) { | |
646 | case AF_INET: | |
647 | avc_print_ipv4_addr(ab, a->u.net.v4info.saddr, | |
648 | a->u.net.sport, | |
649 | "saddr", "src"); | |
650 | avc_print_ipv4_addr(ab, a->u.net.v4info.daddr, | |
651 | a->u.net.dport, | |
652 | "daddr", "dest"); | |
653 | break; | |
654 | case AF_INET6: | |
655 | avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr, | |
656 | a->u.net.sport, | |
657 | "saddr", "src"); | |
658 | avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr, | |
659 | a->u.net.dport, | |
660 | "daddr", "dest"); | |
661 | break; | |
662 | } | |
663 | if (a->u.net.netif) | |
664 | audit_log_format(ab, " netif=%s", | |
665 | a->u.net.netif); | |
666 | break; | |
667 | } | |
668 | } | |
669 | audit_log_format(ab, " "); | |
670 | avc_dump_query(ab, ssid, tsid, tclass); | |
671 | audit_log_end(ab); | |
672 | } | |
673 | ||
674 | /** | |
675 | * avc_add_callback - Register a callback for security events. | |
676 | * @callback: callback function | |
677 | * @events: security events | |
678 | * @ssid: source security identifier or %SECSID_WILD | |
679 | * @tsid: target security identifier or %SECSID_WILD | |
680 | * @tclass: target security class | |
681 | * @perms: permissions | |
682 | * | |
683 | * Register a callback function for events in the set @events | |
684 | * related to the SID pair (@ssid, @tsid) and | |
685 | * and the permissions @perms, interpreting | |
686 | * @perms based on @tclass. Returns %0 on success or | |
687 | * -%ENOMEM if insufficient memory exists to add the callback. | |
688 | */ | |
689 | int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid, | |
690 | u16 tclass, u32 perms, | |
691 | u32 *out_retained), | |
692 | u32 events, u32 ssid, u32 tsid, | |
693 | u16 tclass, u32 perms) | |
694 | { | |
695 | struct avc_callback_node *c; | |
696 | int rc = 0; | |
697 | ||
698 | c = kmalloc(sizeof(*c), GFP_ATOMIC); | |
699 | if (!c) { | |
700 | rc = -ENOMEM; | |
701 | goto out; | |
702 | } | |
703 | ||
704 | c->callback = callback; | |
705 | c->events = events; | |
706 | c->ssid = ssid; | |
707 | c->tsid = tsid; | |
708 | c->perms = perms; | |
709 | c->next = avc_callbacks; | |
710 | avc_callbacks = c; | |
711 | out: | |
712 | return rc; | |
713 | } | |
714 | ||
715 | static inline int avc_sidcmp(u32 x, u32 y) | |
716 | { | |
717 | return (x == y || x == SECSID_WILD || y == SECSID_WILD); | |
718 | } | |
719 | ||
720 | /** | |
721 | * avc_update_node Update an AVC entry | |
722 | * @event : Updating event | |
723 | * @perms : Permission mask bits | |
724 | * @ssid,@tsid,@tclass : identifier of an AVC entry | |
725 | * | |
726 | * if a valid AVC entry doesn't exist,this function returns -ENOENT. | |
727 | * if kmalloc() called internal returns NULL, this function returns -ENOMEM. | |
728 | * otherwise, this function update the AVC entry. The original AVC-entry object | |
729 | * will release later by RCU. | |
730 | */ | |
731 | static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass) | |
732 | { | |
733 | int hvalue, rc = 0; | |
734 | unsigned long flag; | |
735 | struct avc_node *pos, *node, *orig = NULL; | |
736 | ||
737 | node = avc_alloc_node(); | |
738 | if (!node) { | |
739 | rc = -ENOMEM; | |
740 | goto out; | |
741 | } | |
742 | ||
743 | /* Lock the target slot */ | |
744 | hvalue = avc_hash(ssid, tsid, tclass); | |
745 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); | |
746 | ||
747 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list){ | |
748 | if ( ssid==pos->ae.ssid && | |
749 | tsid==pos->ae.tsid && | |
750 | tclass==pos->ae.tclass ){ | |
751 | orig = pos; | |
752 | break; | |
753 | } | |
754 | } | |
755 | ||
756 | if (!orig) { | |
757 | rc = -ENOENT; | |
758 | avc_node_kill(node); | |
759 | goto out_unlock; | |
760 | } | |
761 | ||
762 | /* | |
763 | * Copy and replace original node. | |
764 | */ | |
765 | ||
766 | avc_node_populate(node, ssid, tsid, tclass, &orig->ae); | |
767 | ||
768 | switch (event) { | |
769 | case AVC_CALLBACK_GRANT: | |
770 | node->ae.avd.allowed |= perms; | |
771 | break; | |
772 | case AVC_CALLBACK_TRY_REVOKE: | |
773 | case AVC_CALLBACK_REVOKE: | |
774 | node->ae.avd.allowed &= ~perms; | |
775 | break; | |
776 | case AVC_CALLBACK_AUDITALLOW_ENABLE: | |
777 | node->ae.avd.auditallow |= perms; | |
778 | break; | |
779 | case AVC_CALLBACK_AUDITALLOW_DISABLE: | |
780 | node->ae.avd.auditallow &= ~perms; | |
781 | break; | |
782 | case AVC_CALLBACK_AUDITDENY_ENABLE: | |
783 | node->ae.avd.auditdeny |= perms; | |
784 | break; | |
785 | case AVC_CALLBACK_AUDITDENY_DISABLE: | |
786 | node->ae.avd.auditdeny &= ~perms; | |
787 | break; | |
788 | } | |
789 | avc_node_replace(node, orig); | |
790 | out_unlock: | |
791 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
792 | out: | |
793 | return rc; | |
794 | } | |
795 | ||
796 | /** | |
797 | * avc_ss_reset - Flush the cache and revalidate migrated permissions. | |
798 | * @seqno: policy sequence number | |
799 | */ | |
800 | int avc_ss_reset(u32 seqno) | |
801 | { | |
802 | struct avc_callback_node *c; | |
376bd9cb | 803 | int i, rc = 0, tmprc; |
1da177e4 LT |
804 | unsigned long flag; |
805 | struct avc_node *node; | |
806 | ||
807 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
808 | spin_lock_irqsave(&avc_cache.slots_lock[i], flag); | |
809 | list_for_each_entry(node, &avc_cache.slots[i], list) | |
810 | avc_node_delete(node); | |
811 | spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag); | |
812 | } | |
813 | ||
814 | for (c = avc_callbacks; c; c = c->next) { | |
815 | if (c->events & AVC_CALLBACK_RESET) { | |
376bd9cb DG |
816 | tmprc = c->callback(AVC_CALLBACK_RESET, |
817 | 0, 0, 0, 0, NULL); | |
818 | /* save the first error encountered for the return | |
819 | value and continue processing the callbacks */ | |
820 | if (!rc) | |
821 | rc = tmprc; | |
1da177e4 LT |
822 | } |
823 | } | |
824 | ||
825 | avc_latest_notif_update(seqno, 0); | |
1da177e4 LT |
826 | return rc; |
827 | } | |
828 | ||
829 | /** | |
830 | * avc_has_perm_noaudit - Check permissions but perform no auditing. | |
831 | * @ssid: source security identifier | |
832 | * @tsid: target security identifier | |
833 | * @tclass: target security class | |
834 | * @requested: requested permissions, interpreted based on @tclass | |
835 | * @avd: access vector decisions | |
836 | * | |
837 | * Check the AVC to determine whether the @requested permissions are granted | |
838 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
839 | * based on @tclass, and call the security server on a cache miss to obtain | |
840 | * a new decision and add it to the cache. Return a copy of the decisions | |
841 | * in @avd. Return %0 if all @requested permissions are granted, | |
842 | * -%EACCES if any permissions are denied, or another -errno upon | |
843 | * other errors. This function is typically called by avc_has_perm(), | |
844 | * but may also be called directly to separate permission checking from | |
845 | * auditing, e.g. in cases where a lock must be held for the check but | |
846 | * should be released for the auditing. | |
847 | */ | |
848 | int avc_has_perm_noaudit(u32 ssid, u32 tsid, | |
849 | u16 tclass, u32 requested, | |
850 | struct av_decision *avd) | |
851 | { | |
852 | struct avc_node *node; | |
853 | struct avc_entry entry, *p_ae; | |
854 | int rc = 0; | |
855 | u32 denied; | |
856 | ||
857 | rcu_read_lock(); | |
858 | ||
859 | node = avc_lookup(ssid, tsid, tclass, requested); | |
860 | if (!node) { | |
861 | rcu_read_unlock(); | |
862 | rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd); | |
863 | if (rc) | |
864 | goto out; | |
865 | rcu_read_lock(); | |
866 | node = avc_insert(ssid,tsid,tclass,&entry); | |
867 | } | |
868 | ||
869 | p_ae = node ? &node->ae : &entry; | |
870 | ||
871 | if (avd) | |
872 | memcpy(avd, &p_ae->avd, sizeof(*avd)); | |
873 | ||
874 | denied = requested & ~(p_ae->avd.allowed); | |
875 | ||
876 | if (!requested || denied) { | |
877 | if (selinux_enforcing) | |
878 | rc = -EACCES; | |
879 | else | |
880 | if (node) | |
881 | avc_update_node(AVC_CALLBACK_GRANT,requested, | |
882 | ssid,tsid,tclass); | |
883 | } | |
884 | ||
885 | rcu_read_unlock(); | |
886 | out: | |
887 | return rc; | |
888 | } | |
889 | ||
890 | /** | |
891 | * avc_has_perm - Check permissions and perform any appropriate auditing. | |
892 | * @ssid: source security identifier | |
893 | * @tsid: target security identifier | |
894 | * @tclass: target security class | |
895 | * @requested: requested permissions, interpreted based on @tclass | |
896 | * @auditdata: auxiliary audit data | |
897 | * | |
898 | * Check the AVC to determine whether the @requested permissions are granted | |
899 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
900 | * based on @tclass, and call the security server on a cache miss to obtain | |
901 | * a new decision and add it to the cache. Audit the granting or denial of | |
902 | * permissions in accordance with the policy. Return %0 if all @requested | |
903 | * permissions are granted, -%EACCES if any permissions are denied, or | |
904 | * another -errno upon other errors. | |
905 | */ | |
906 | int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, | |
907 | u32 requested, struct avc_audit_data *auditdata) | |
908 | { | |
909 | struct av_decision avd; | |
910 | int rc; | |
911 | ||
912 | rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, &avd); | |
913 | avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); | |
914 | return rc; | |
915 | } |