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20#include <linux/kernel.h>
21#include <linux/slab.h>
22#include <linux/errno.h>
23#include "avtab.h"
24#include "policydb.h"
25
26static struct kmem_cache *avtab_node_cachep;
27static struct kmem_cache *avtab_xperms_cachep;
28
29
30
31
32static inline int avtab_hash(struct avtab_key *keyp, u32 mask)
33{
34 static const u32 c1 = 0xcc9e2d51;
35 static const u32 c2 = 0x1b873593;
36 static const u32 r1 = 15;
37 static const u32 r2 = 13;
38 static const u32 m = 5;
39 static const u32 n = 0xe6546b64;
40
41 u32 hash = 0;
42
43#define mix(input) { \
44 u32 v = input; \
45 v *= c1; \
46 v = (v << r1) | (v >> (32 - r1)); \
47 v *= c2; \
48 hash ^= v; \
49 hash = (hash << r2) | (hash >> (32 - r2)); \
50 hash = hash * m + n; \
51}
52
53 mix(keyp->target_class);
54 mix(keyp->target_type);
55 mix(keyp->source_type);
56
57#undef mix
58
59 hash ^= hash >> 16;
60 hash *= 0x85ebca6b;
61 hash ^= hash >> 13;
62 hash *= 0xc2b2ae35;
63 hash ^= hash >> 16;
64
65 return hash & mask;
66}
67
68static struct avtab_node*
69avtab_insert_node(struct avtab *h, int hvalue,
70 struct avtab_node *prev, struct avtab_node *cur,
71 struct avtab_key *key, struct avtab_datum *datum)
72{
73 struct avtab_node *newnode;
74 struct avtab_extended_perms *xperms;
75 newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
76 if (newnode == NULL)
77 return NULL;
78 newnode->key = *key;
79
80 if (key->specified & AVTAB_XPERMS) {
81 xperms = kmem_cache_zalloc(avtab_xperms_cachep, GFP_KERNEL);
82 if (xperms == NULL) {
83 kmem_cache_free(avtab_node_cachep, newnode);
84 return NULL;
85 }
86 *xperms = *(datum->u.xperms);
87 newnode->datum.u.xperms = xperms;
88 } else {
89 newnode->datum.u.data = datum->u.data;
90 }
91
92 if (prev) {
93 newnode->next = prev->next;
94 prev->next = newnode;
95 } else {
96 struct avtab_node **n = &h->htable[hvalue];
97
98 newnode->next = *n;
99 *n = newnode;
100 }
101
102 h->nel++;
103 return newnode;
104}
105
106static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
107{
108 int hvalue;
109 struct avtab_node *prev, *cur, *newnode;
110 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
111
112 if (!h)
113 return -EINVAL;
114
115 hvalue = avtab_hash(key, h->mask);
116 for (prev = NULL, cur = h->htable[hvalue];
117 cur;
118 prev = cur, cur = cur->next) {
119 if (key->source_type == cur->key.source_type &&
120 key->target_type == cur->key.target_type &&
121 key->target_class == cur->key.target_class &&
122 (specified & cur->key.specified)) {
123
124 if (specified & AVTAB_XPERMS)
125 break;
126 return -EEXIST;
127 }
128 if (key->source_type < cur->key.source_type)
129 break;
130 if (key->source_type == cur->key.source_type &&
131 key->target_type < cur->key.target_type)
132 break;
133 if (key->source_type == cur->key.source_type &&
134 key->target_type == cur->key.target_type &&
135 key->target_class < cur->key.target_class)
136 break;
137 }
138
139 newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);
140 if (!newnode)
141 return -ENOMEM;
142
143 return 0;
144}
145
146
147
148
149
150struct avtab_node *
151avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
152{
153 int hvalue;
154 struct avtab_node *prev, *cur;
155 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
156
157 if (!h)
158 return NULL;
159 hvalue = avtab_hash(key, h->mask);
160 for (prev = NULL, cur = h->htable[hvalue];
161 cur;
162 prev = cur, cur = cur->next) {
163 if (key->source_type == cur->key.source_type &&
164 key->target_type == cur->key.target_type &&
165 key->target_class == cur->key.target_class &&
166 (specified & cur->key.specified))
167 break;
168 if (key->source_type < cur->key.source_type)
169 break;
170 if (key->source_type == cur->key.source_type &&
171 key->target_type < cur->key.target_type)
172 break;
173 if (key->source_type == cur->key.source_type &&
174 key->target_type == cur->key.target_type &&
175 key->target_class < cur->key.target_class)
176 break;
177 }
178 return avtab_insert_node(h, hvalue, prev, cur, key, datum);
179}
180
181struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
182{
183 int hvalue;
184 struct avtab_node *cur;
185 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
186
187 if (!h)
188 return NULL;
189
190 hvalue = avtab_hash(key, h->mask);
191 for (cur = h->htable[hvalue]; cur;
192 cur = cur->next) {
193 if (key->source_type == cur->key.source_type &&
194 key->target_type == cur->key.target_type &&
195 key->target_class == cur->key.target_class &&
196 (specified & cur->key.specified))
197 return &cur->datum;
198
199 if (key->source_type < cur->key.source_type)
200 break;
201 if (key->source_type == cur->key.source_type &&
202 key->target_type < cur->key.target_type)
203 break;
204 if (key->source_type == cur->key.source_type &&
205 key->target_type == cur->key.target_type &&
206 key->target_class < cur->key.target_class)
207 break;
208 }
209
210 return NULL;
211}
212
213
214
215
216struct avtab_node*
217avtab_search_node(struct avtab *h, struct avtab_key *key)
218{
219 int hvalue;
220 struct avtab_node *cur;
221 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
222
223 if (!h)
224 return NULL;
225
226 hvalue = avtab_hash(key, h->mask);
227 for (cur = h->htable[hvalue]; cur;
228 cur = cur->next) {
229 if (key->source_type == cur->key.source_type &&
230 key->target_type == cur->key.target_type &&
231 key->target_class == cur->key.target_class &&
232 (specified & cur->key.specified))
233 return cur;
234
235 if (key->source_type < cur->key.source_type)
236 break;
237 if (key->source_type == cur->key.source_type &&
238 key->target_type < cur->key.target_type)
239 break;
240 if (key->source_type == cur->key.source_type &&
241 key->target_type == cur->key.target_type &&
242 key->target_class < cur->key.target_class)
243 break;
244 }
245 return NULL;
246}
247
248struct avtab_node*
249avtab_search_node_next(struct avtab_node *node, int specified)
250{
251 struct avtab_node *cur;
252
253 if (!node)
254 return NULL;
255
256 specified &= ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
257 for (cur = node->next; cur; cur = cur->next) {
258 if (node->key.source_type == cur->key.source_type &&
259 node->key.target_type == cur->key.target_type &&
260 node->key.target_class == cur->key.target_class &&
261 (specified & cur->key.specified))
262 return cur;
263
264 if (node->key.source_type < cur->key.source_type)
265 break;
266 if (node->key.source_type == cur->key.source_type &&
267 node->key.target_type < cur->key.target_type)
268 break;
269 if (node->key.source_type == cur->key.source_type &&
270 node->key.target_type == cur->key.target_type &&
271 node->key.target_class < cur->key.target_class)
272 break;
273 }
274 return NULL;
275}
276
277void avtab_destroy(struct avtab *h)
278{
279 int i;
280 struct avtab_node *cur, *temp;
281
282 if (!h)
283 return;
284
285 for (i = 0; i < h->nslot; i++) {
286 cur = h->htable[i];
287 while (cur) {
288 temp = cur;
289 cur = cur->next;
290 if (temp->key.specified & AVTAB_XPERMS)
291 kmem_cache_free(avtab_xperms_cachep,
292 temp->datum.u.xperms);
293 kmem_cache_free(avtab_node_cachep, temp);
294 }
295 }
296 kvfree(h->htable);
297 h->htable = NULL;
298 h->nslot = 0;
299 h->mask = 0;
300}
301
302void avtab_init(struct avtab *h)
303{
304 h->htable = NULL;
305 h->nel = 0;
306}
307
308int avtab_alloc(struct avtab *h, u32 nrules)
309{
310 u32 mask = 0;
311 u32 shift = 0;
312 u32 work = nrules;
313 u32 nslot = 0;
314
315 if (nrules == 0)
316 goto avtab_alloc_out;
317
318 while (work) {
319 work = work >> 1;
320 shift++;
321 }
322 if (shift > 2)
323 shift = shift - 2;
324 nslot = 1 << shift;
325 if (nslot > MAX_AVTAB_HASH_BUCKETS)
326 nslot = MAX_AVTAB_HASH_BUCKETS;
327 mask = nslot - 1;
328
329 h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL);
330 if (!h->htable)
331 return -ENOMEM;
332
333 avtab_alloc_out:
334 h->nel = 0;
335 h->nslot = nslot;
336 h->mask = mask;
337 pr_debug("SELinux: %d avtab hash slots, %d rules.\n",
338 h->nslot, nrules);
339 return 0;
340}
341
342int avtab_duplicate(struct avtab *new, struct avtab *orig)
343{
344 int i;
345 struct avtab_node *node, *tmp, *tail;
346
347 memset(new, 0, sizeof(*new));
348
349 new->htable = kvcalloc(orig->nslot, sizeof(void *), GFP_KERNEL);
350 if (!new->htable)
351 return -ENOMEM;
352 new->nslot = orig->nslot;
353 new->mask = orig->mask;
354
355 for (i = 0; i < orig->nslot; i++) {
356 tail = NULL;
357 for (node = orig->htable[i]; node; node = node->next) {
358 tmp = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
359 if (!tmp)
360 goto error;
361 tmp->key = node->key;
362 if (tmp->key.specified & AVTAB_XPERMS) {
363 tmp->datum.u.xperms =
364 kmem_cache_zalloc(avtab_xperms_cachep,
365 GFP_KERNEL);
366 if (!tmp->datum.u.xperms) {
367 kmem_cache_free(avtab_node_cachep, tmp);
368 goto error;
369 }
370 tmp->datum.u.xperms = node->datum.u.xperms;
371 } else
372 tmp->datum.u.data = node->datum.u.data;
373
374 if (tail)
375 tail->next = tmp;
376 else
377 new->htable[i] = tmp;
378
379 tail = tmp;
380 new->nel++;
381 }
382 }
383
384 return 0;
385error:
386 avtab_destroy(new);
387 return -ENOMEM;
388}
389
390void avtab_hash_eval(struct avtab *h, char *tag)
391{
392 int i, chain_len, slots_used, max_chain_len;
393 unsigned long long chain2_len_sum;
394 struct avtab_node *cur;
395
396 slots_used = 0;
397 max_chain_len = 0;
398 chain2_len_sum = 0;
399 for (i = 0; i < h->nslot; i++) {
400 cur = h->htable[i];
401 if (cur) {
402 slots_used++;
403 chain_len = 0;
404 while (cur) {
405 chain_len++;
406 cur = cur->next;
407 }
408
409 if (chain_len > max_chain_len)
410 max_chain_len = chain_len;
411 chain2_len_sum += chain_len * chain_len;
412 }
413 }
414
415 pr_debug("SELinux: %s: %d entries and %d/%d buckets used, "
416 "longest chain length %d sum of chain length^2 %llu\n",
417 tag, h->nel, slots_used, h->nslot, max_chain_len,
418 chain2_len_sum);
419}
420
421static uint16_t spec_order[] = {
422 AVTAB_ALLOWED,
423 AVTAB_AUDITDENY,
424 AVTAB_AUDITALLOW,
425 AVTAB_TRANSITION,
426 AVTAB_CHANGE,
427 AVTAB_MEMBER,
428 AVTAB_XPERMS_ALLOWED,
429 AVTAB_XPERMS_AUDITALLOW,
430 AVTAB_XPERMS_DONTAUDIT
431};
432
433int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
434 int (*insertf)(struct avtab *a, struct avtab_key *k,
435 struct avtab_datum *d, void *p),
436 void *p)
437{
438 __le16 buf16[4];
439 u16 enabled;
440 u32 items, items2, val, vers = pol->policyvers;
441 struct avtab_key key;
442 struct avtab_datum datum;
443 struct avtab_extended_perms xperms;
444 __le32 buf32[ARRAY_SIZE(xperms.perms.p)];
445 int i, rc;
446 unsigned set;
447
448 memset(&key, 0, sizeof(struct avtab_key));
449 memset(&datum, 0, sizeof(struct avtab_datum));
450
451 if (vers < POLICYDB_VERSION_AVTAB) {
452 rc = next_entry(buf32, fp, sizeof(u32));
453 if (rc) {
454 pr_err("SELinux: avtab: truncated entry\n");
455 return rc;
456 }
457 items2 = le32_to_cpu(buf32[0]);
458 if (items2 > ARRAY_SIZE(buf32)) {
459 pr_err("SELinux: avtab: entry overflow\n");
460 return -EINVAL;
461
462 }
463 rc = next_entry(buf32, fp, sizeof(u32)*items2);
464 if (rc) {
465 pr_err("SELinux: avtab: truncated entry\n");
466 return rc;
467 }
468 items = 0;
469
470 val = le32_to_cpu(buf32[items++]);
471 key.source_type = (u16)val;
472 if (key.source_type != val) {
473 pr_err("SELinux: avtab: truncated source type\n");
474 return -EINVAL;
475 }
476 val = le32_to_cpu(buf32[items++]);
477 key.target_type = (u16)val;
478 if (key.target_type != val) {
479 pr_err("SELinux: avtab: truncated target type\n");
480 return -EINVAL;
481 }
482 val = le32_to_cpu(buf32[items++]);
483 key.target_class = (u16)val;
484 if (key.target_class != val) {
485 pr_err("SELinux: avtab: truncated target class\n");
486 return -EINVAL;
487 }
488
489 val = le32_to_cpu(buf32[items++]);
490 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
491
492 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
493 pr_err("SELinux: avtab: null entry\n");
494 return -EINVAL;
495 }
496 if ((val & AVTAB_AV) &&
497 (val & AVTAB_TYPE)) {
498 pr_err("SELinux: avtab: entry has both access vectors and types\n");
499 return -EINVAL;
500 }
501 if (val & AVTAB_XPERMS) {
502 pr_err("SELinux: avtab: entry has extended permissions\n");
503 return -EINVAL;
504 }
505
506 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
507 if (val & spec_order[i]) {
508 key.specified = spec_order[i] | enabled;
509 datum.u.data = le32_to_cpu(buf32[items++]);
510 rc = insertf(a, &key, &datum, p);
511 if (rc)
512 return rc;
513 }
514 }
515
516 if (items != items2) {
517 pr_err("SELinux: avtab: entry only had %d items, expected %d\n",
518 items2, items);
519 return -EINVAL;
520 }
521 return 0;
522 }
523
524 rc = next_entry(buf16, fp, sizeof(u16)*4);
525 if (rc) {
526 pr_err("SELinux: avtab: truncated entry\n");
527 return rc;
528 }
529
530 items = 0;
531 key.source_type = le16_to_cpu(buf16[items++]);
532 key.target_type = le16_to_cpu(buf16[items++]);
533 key.target_class = le16_to_cpu(buf16[items++]);
534 key.specified = le16_to_cpu(buf16[items++]);
535
536 if (!policydb_type_isvalid(pol, key.source_type) ||
537 !policydb_type_isvalid(pol, key.target_type) ||
538 !policydb_class_isvalid(pol, key.target_class)) {
539 pr_err("SELinux: avtab: invalid type or class\n");
540 return -EINVAL;
541 }
542
543 set = 0;
544 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
545 if (key.specified & spec_order[i])
546 set++;
547 }
548 if (!set || set > 1) {
549 pr_err("SELinux: avtab: more than one specifier\n");
550 return -EINVAL;
551 }
552
553 if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
554 (key.specified & AVTAB_XPERMS)) {
555 pr_err("SELinux: avtab: policy version %u does not "
556 "support extended permissions rules and one "
557 "was specified\n", vers);
558 return -EINVAL;
559 } else if (key.specified & AVTAB_XPERMS) {
560 memset(&xperms, 0, sizeof(struct avtab_extended_perms));
561 rc = next_entry(&xperms.specified, fp, sizeof(u8));
562 if (rc) {
563 pr_err("SELinux: avtab: truncated entry\n");
564 return rc;
565 }
566 rc = next_entry(&xperms.driver, fp, sizeof(u8));
567 if (rc) {
568 pr_err("SELinux: avtab: truncated entry\n");
569 return rc;
570 }
571 rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p));
572 if (rc) {
573 pr_err("SELinux: avtab: truncated entry\n");
574 return rc;
575 }
576 for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++)
577 xperms.perms.p[i] = le32_to_cpu(buf32[i]);
578 datum.u.xperms = &xperms;
579 } else {
580 rc = next_entry(buf32, fp, sizeof(u32));
581 if (rc) {
582 pr_err("SELinux: avtab: truncated entry\n");
583 return rc;
584 }
585 datum.u.data = le32_to_cpu(*buf32);
586 }
587 if ((key.specified & AVTAB_TYPE) &&
588 !policydb_type_isvalid(pol, datum.u.data)) {
589 pr_err("SELinux: avtab: invalid type\n");
590 return -EINVAL;
591 }
592 return insertf(a, &key, &datum, p);
593}
594
595static int avtab_insertf(struct avtab *a, struct avtab_key *k,
596 struct avtab_datum *d, void *p)
597{
598 return avtab_insert(a, k, d);
599}
600
601int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
602{
603 int rc;
604 __le32 buf[1];
605 u32 nel, i;
606
607
608 rc = next_entry(buf, fp, sizeof(u32));
609 if (rc < 0) {
610 pr_err("SELinux: avtab: truncated table\n");
611 goto bad;
612 }
613 nel = le32_to_cpu(buf[0]);
614 if (!nel) {
615 pr_err("SELinux: avtab: table is empty\n");
616 rc = -EINVAL;
617 goto bad;
618 }
619
620 rc = avtab_alloc(a, nel);
621 if (rc)
622 goto bad;
623
624 for (i = 0; i < nel; i++) {
625 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
626 if (rc) {
627 if (rc == -ENOMEM)
628 pr_err("SELinux: avtab: out of memory\n");
629 else if (rc == -EEXIST)
630 pr_err("SELinux: avtab: duplicate entry\n");
631
632 goto bad;
633 }
634 }
635
636 rc = 0;
637out:
638 return rc;
639
640bad:
641 avtab_destroy(a);
642 goto out;
643}
644
645int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
646{
647 __le16 buf16[4];
648 __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)];
649 int rc;
650 unsigned int i;
651
652 buf16[0] = cpu_to_le16(cur->key.source_type);
653 buf16[1] = cpu_to_le16(cur->key.target_type);
654 buf16[2] = cpu_to_le16(cur->key.target_class);
655 buf16[3] = cpu_to_le16(cur->key.specified);
656 rc = put_entry(buf16, sizeof(u16), 4, fp);
657 if (rc)
658 return rc;
659
660 if (cur->key.specified & AVTAB_XPERMS) {
661 rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp);
662 if (rc)
663 return rc;
664 rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp);
665 if (rc)
666 return rc;
667 for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++)
668 buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]);
669 rc = put_entry(buf32, sizeof(u32),
670 ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp);
671 } else {
672 buf32[0] = cpu_to_le32(cur->datum.u.data);
673 rc = put_entry(buf32, sizeof(u32), 1, fp);
674 }
675 if (rc)
676 return rc;
677 return 0;
678}
679
680int avtab_write(struct policydb *p, struct avtab *a, void *fp)
681{
682 unsigned int i;
683 int rc = 0;
684 struct avtab_node *cur;
685 __le32 buf[1];
686
687 buf[0] = cpu_to_le32(a->nel);
688 rc = put_entry(buf, sizeof(u32), 1, fp);
689 if (rc)
690 return rc;
691
692 for (i = 0; i < a->nslot; i++) {
693 for (cur = a->htable[i]; cur;
694 cur = cur->next) {
695 rc = avtab_write_item(p, cur, fp);
696 if (rc)
697 return rc;
698 }
699 }
700
701 return rc;
702}
703
704void __init avtab_cache_init(void)
705{
706 avtab_node_cachep = kmem_cache_create("avtab_node",
707 sizeof(struct avtab_node),
708 0, SLAB_PANIC, NULL);
709 avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms",
710 sizeof(struct avtab_extended_perms),
711 0, SLAB_PANIC, NULL);
712}
713
