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