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1/*
2 * Implementation of the access vector table type.
3 *
4 * Author : Stephen Smalley, <sds@tycho.nsa.gov>
5 */
6
7/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
8 *
9 * Added conditional policy language extensions
10 *
11 * Copyright (C) 2003 Tresys Technology, LLC
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation, version 2.
15 *
16 * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
17 * Tuned number of hash slots for avtab to reduce memory usage
18 */
19
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/* Based on MurmurHash3, written by Austin Appleby and placed in the
30 * public domain.
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 /* extended perms may not be unique */
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/* Unlike avtab_insert(), this function allow multiple insertions of the same
147 * key/specified mask into the table, as needed by the conditional avtab.
148 * It also returns a pointer to the node inserted.
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/* This search function returns a node pointer, and can be used in
214 * conjunction with avtab_search_next_node()
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
302int avtab_init(struct avtab *h)
303{
304 kvfree(h->htable);
305 h->htable = NULL;
306 h->nel = 0;
307 return 0;
308}
309
310int avtab_alloc(struct avtab *h, u32 nrules)
311{
312 u32 mask = 0;
313 u32 shift = 0;
314 u32 work = nrules;
315 u32 nslot = 0;
316
317 if (nrules == 0)
318 goto avtab_alloc_out;
319
320 while (work) {
321 work = work >> 1;
322 shift++;
323 }
324 if (shift > 2)
325 shift = shift - 2;
326 nslot = 1 << shift;
327 if (nslot > MAX_AVTAB_HASH_BUCKETS)
328 nslot = MAX_AVTAB_HASH_BUCKETS;
329 mask = nslot - 1;
330
331 h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL);
332 if (!h->htable)
333 return -ENOMEM;
334
335 avtab_alloc_out:
336 h->nel = 0;
337 h->nslot = nslot;
338 h->mask = mask;
339 pr_debug("SELinux: %d avtab hash slots, %d rules.\n",
340 h->nslot, nrules);
341 return 0;
342}
343
344void avtab_hash_eval(struct avtab *h, char *tag)
345{
346 int i, chain_len, slots_used, max_chain_len;
347 unsigned long long chain2_len_sum;
348 struct avtab_node *cur;
349
350 slots_used = 0;
351 max_chain_len = 0;
352 chain2_len_sum = 0;
353 for (i = 0; i < h->nslot; i++) {
354 cur = h->htable[i];
355 if (cur) {
356 slots_used++;
357 chain_len = 0;
358 while (cur) {
359 chain_len++;
360 cur = cur->next;
361 }
362
363 if (chain_len > max_chain_len)
364 max_chain_len = chain_len;
365 chain2_len_sum += chain_len * chain_len;
366 }
367 }
368
369 pr_debug("SELinux: %s: %d entries and %d/%d buckets used, "
370 "longest chain length %d sum of chain length^2 %llu\n",
371 tag, h->nel, slots_used, h->nslot, max_chain_len,
372 chain2_len_sum);
373}
374
375static uint16_t spec_order[] = {
376 AVTAB_ALLOWED,
377 AVTAB_AUDITDENY,
378 AVTAB_AUDITALLOW,
379 AVTAB_TRANSITION,
380 AVTAB_CHANGE,
381 AVTAB_MEMBER,
382 AVTAB_XPERMS_ALLOWED,
383 AVTAB_XPERMS_AUDITALLOW,
384 AVTAB_XPERMS_DONTAUDIT
385};
386
387int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
388 int (*insertf)(struct avtab *a, struct avtab_key *k,
389 struct avtab_datum *d, void *p),
390 void *p)
391{
392 __le16 buf16[4];
393 u16 enabled;
394 u32 items, items2, val, vers = pol->policyvers;
395 struct avtab_key key;
396 struct avtab_datum datum;
397 struct avtab_extended_perms xperms;
398 __le32 buf32[ARRAY_SIZE(xperms.perms.p)];
399 int i, rc;
400 unsigned set;
401
402 memset(&key, 0, sizeof(struct avtab_key));
403 memset(&datum, 0, sizeof(struct avtab_datum));
404
405 if (vers < POLICYDB_VERSION_AVTAB) {
406 rc = next_entry(buf32, fp, sizeof(u32));
407 if (rc) {
408 pr_err("SELinux: avtab: truncated entry\n");
409 return rc;
410 }
411 items2 = le32_to_cpu(buf32[0]);
412 if (items2 > ARRAY_SIZE(buf32)) {
413 pr_err("SELinux: avtab: entry overflow\n");
414 return -EINVAL;
415
416 }
417 rc = next_entry(buf32, fp, sizeof(u32)*items2);
418 if (rc) {
419 pr_err("SELinux: avtab: truncated entry\n");
420 return rc;
421 }
422 items = 0;
423
424 val = le32_to_cpu(buf32[items++]);
425 key.source_type = (u16)val;
426 if (key.source_type != val) {
427 pr_err("SELinux: avtab: truncated source type\n");
428 return -EINVAL;
429 }
430 val = le32_to_cpu(buf32[items++]);
431 key.target_type = (u16)val;
432 if (key.target_type != val) {
433 pr_err("SELinux: avtab: truncated target type\n");
434 return -EINVAL;
435 }
436 val = le32_to_cpu(buf32[items++]);
437 key.target_class = (u16)val;
438 if (key.target_class != val) {
439 pr_err("SELinux: avtab: truncated target class\n");
440 return -EINVAL;
441 }
442
443 val = le32_to_cpu(buf32[items++]);
444 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
445
446 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
447 pr_err("SELinux: avtab: null entry\n");
448 return -EINVAL;
449 }
450 if ((val & AVTAB_AV) &&
451 (val & AVTAB_TYPE)) {
452 pr_err("SELinux: avtab: entry has both access vectors and types\n");
453 return -EINVAL;
454 }
455 if (val & AVTAB_XPERMS) {
456 pr_err("SELinux: avtab: entry has extended permissions\n");
457 return -EINVAL;
458 }
459
460 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
461 if (val & spec_order[i]) {
462 key.specified = spec_order[i] | enabled;
463 datum.u.data = le32_to_cpu(buf32[items++]);
464 rc = insertf(a, &key, &datum, p);
465 if (rc)
466 return rc;
467 }
468 }
469
470 if (items != items2) {
471 pr_err("SELinux: avtab: entry only had %d items, expected %d\n",
472 items2, items);
473 return -EINVAL;
474 }
475 return 0;
476 }
477
478 rc = next_entry(buf16, fp, sizeof(u16)*4);
479 if (rc) {
480 pr_err("SELinux: avtab: truncated entry\n");
481 return rc;
482 }
483
484 items = 0;
485 key.source_type = le16_to_cpu(buf16[items++]);
486 key.target_type = le16_to_cpu(buf16[items++]);
487 key.target_class = le16_to_cpu(buf16[items++]);
488 key.specified = le16_to_cpu(buf16[items++]);
489
490 if (!policydb_type_isvalid(pol, key.source_type) ||
491 !policydb_type_isvalid(pol, key.target_type) ||
492 !policydb_class_isvalid(pol, key.target_class)) {
493 pr_err("SELinux: avtab: invalid type or class\n");
494 return -EINVAL;
495 }
496
497 set = 0;
498 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
499 if (key.specified & spec_order[i])
500 set++;
501 }
502 if (!set || set > 1) {
503 pr_err("SELinux: avtab: more than one specifier\n");
504 return -EINVAL;
505 }
506
507 if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
508 (key.specified & AVTAB_XPERMS)) {
509 pr_err("SELinux: avtab: policy version %u does not "
510 "support extended permissions rules and one "
511 "was specified\n", vers);
512 return -EINVAL;
513 } else if (key.specified & AVTAB_XPERMS) {
514 memset(&xperms, 0, sizeof(struct avtab_extended_perms));
515 rc = next_entry(&xperms.specified, fp, sizeof(u8));
516 if (rc) {
517 pr_err("SELinux: avtab: truncated entry\n");
518 return rc;
519 }
520 rc = next_entry(&xperms.driver, fp, sizeof(u8));
521 if (rc) {
522 pr_err("SELinux: avtab: truncated entry\n");
523 return rc;
524 }
525 rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p));
526 if (rc) {
527 pr_err("SELinux: avtab: truncated entry\n");
528 return rc;
529 }
530 for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++)
531 xperms.perms.p[i] = le32_to_cpu(buf32[i]);
532 datum.u.xperms = &xperms;
533 } else {
534 rc = next_entry(buf32, fp, sizeof(u32));
535 if (rc) {
536 pr_err("SELinux: avtab: truncated entry\n");
537 return rc;
538 }
539 datum.u.data = le32_to_cpu(*buf32);
540 }
541 if ((key.specified & AVTAB_TYPE) &&
542 !policydb_type_isvalid(pol, datum.u.data)) {
543 pr_err("SELinux: avtab: invalid type\n");
544 return -EINVAL;
545 }
546 return insertf(a, &key, &datum, p);
547}
548
549static int avtab_insertf(struct avtab *a, struct avtab_key *k,
550 struct avtab_datum *d, void *p)
551{
552 return avtab_insert(a, k, d);
553}
554
555int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
556{
557 int rc;
558 __le32 buf[1];
559 u32 nel, i;
560
561
562 rc = next_entry(buf, fp, sizeof(u32));
563 if (rc < 0) {
564 pr_err("SELinux: avtab: truncated table\n");
565 goto bad;
566 }
567 nel = le32_to_cpu(buf[0]);
568 if (!nel) {
569 pr_err("SELinux: avtab: table is empty\n");
570 rc = -EINVAL;
571 goto bad;
572 }
573
574 rc = avtab_alloc(a, nel);
575 if (rc)
576 goto bad;
577
578 for (i = 0; i < nel; i++) {
579 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
580 if (rc) {
581 if (rc == -ENOMEM)
582 pr_err("SELinux: avtab: out of memory\n");
583 else if (rc == -EEXIST)
584 pr_err("SELinux: avtab: duplicate entry\n");
585
586 goto bad;
587 }
588 }
589
590 rc = 0;
591out:
592 return rc;
593
594bad:
595 avtab_destroy(a);
596 goto out;
597}
598
599int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
600{
601 __le16 buf16[4];
602 __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)];
603 int rc;
604 unsigned int i;
605
606 buf16[0] = cpu_to_le16(cur->key.source_type);
607 buf16[1] = cpu_to_le16(cur->key.target_type);
608 buf16[2] = cpu_to_le16(cur->key.target_class);
609 buf16[3] = cpu_to_le16(cur->key.specified);
610 rc = put_entry(buf16, sizeof(u16), 4, fp);
611 if (rc)
612 return rc;
613
614 if (cur->key.specified & AVTAB_XPERMS) {
615 rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp);
616 if (rc)
617 return rc;
618 rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp);
619 if (rc)
620 return rc;
621 for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++)
622 buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]);
623 rc = put_entry(buf32, sizeof(u32),
624 ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp);
625 } else {
626 buf32[0] = cpu_to_le32(cur->datum.u.data);
627 rc = put_entry(buf32, sizeof(u32), 1, fp);
628 }
629 if (rc)
630 return rc;
631 return 0;
632}
633
634int avtab_write(struct policydb *p, struct avtab *a, void *fp)
635{
636 unsigned int i;
637 int rc = 0;
638 struct avtab_node *cur;
639 __le32 buf[1];
640
641 buf[0] = cpu_to_le32(a->nel);
642 rc = put_entry(buf, sizeof(u32), 1, fp);
643 if (rc)
644 return rc;
645
646 for (i = 0; i < a->nslot; i++) {
647 for (cur = a->htable[i]; cur;
648 cur = cur->next) {
649 rc = avtab_write_item(p, cur, fp);
650 if (rc)
651 return rc;
652 }
653 }
654
655 return rc;
656}
657
658void __init 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}
1/*
2 * Implementation of the access vector table type.
3 *
4 * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
5 */
6
7/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
8 *
9 * Added conditional policy language extensions
10 *
11 * Copyright (C) 2003 Tresys Technology, LLC
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation, version 2.
15 *
16 * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
17 * Tuned number of hash slots for avtab to reduce memory usage
18 */
19
20#include <linux/bitops.h>
21#include <linux/kernel.h>
22#include <linux/slab.h>
23#include <linux/errno.h>
24#include "avtab.h"
25#include "policydb.h"
26
27static struct kmem_cache *avtab_node_cachep __ro_after_init;
28static struct kmem_cache *avtab_xperms_cachep __ro_after_init;
29
30/* Based on MurmurHash3, written by Austin Appleby and placed in the
31 * public domain.
32 */
33static inline u32 avtab_hash(const struct avtab_key *keyp, u32 mask)
34{
35 static const u32 c1 = 0xcc9e2d51;
36 static const u32 c2 = 0x1b873593;
37 static const u32 r1 = 15;
38 static const u32 r2 = 13;
39 static const u32 m = 5;
40 static const u32 n = 0xe6546b64;
41
42 u32 hash = 0;
43
44#define mix(input) do { \
45 u32 v = input; \
46 v *= c1; \
47 v = (v << r1) | (v >> (32 - r1)); \
48 v *= c2; \
49 hash ^= v; \
50 hash = (hash << r2) | (hash >> (32 - r2)); \
51 hash = hash * m + n; \
52 } while (0)
53
54 mix(keyp->target_class);
55 mix(keyp->target_type);
56 mix(keyp->source_type);
57
58#undef mix
59
60 hash ^= hash >> 16;
61 hash *= 0x85ebca6b;
62 hash ^= hash >> 13;
63 hash *= 0xc2b2ae35;
64 hash ^= hash >> 16;
65
66 return hash & mask;
67}
68
69static struct avtab_node*
70avtab_insert_node(struct avtab *h, struct avtab_node **dst,
71 const struct avtab_key *key, const 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 newnode->next = *dst;
93 *dst = newnode;
94
95 h->nel++;
96 return newnode;
97}
98
99static int avtab_node_cmp(const struct avtab_key *key1,
100 const struct avtab_key *key2)
101{
102 u16 specified = key1->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
103
104 if (key1->source_type == key2->source_type &&
105 key1->target_type == key2->target_type &&
106 key1->target_class == key2->target_class &&
107 (specified & key2->specified))
108 return 0;
109 if (key1->source_type < key2->source_type)
110 return -1;
111 if (key1->source_type == key2->source_type &&
112 key1->target_type < key2->target_type)
113 return -1;
114 if (key1->source_type == key2->source_type &&
115 key1->target_type == key2->target_type &&
116 key1->target_class < key2->target_class)
117 return -1;
118 return 1;
119}
120
121static int avtab_insert(struct avtab *h, const struct avtab_key *key,
122 const struct avtab_datum *datum)
123{
124 u32 hvalue;
125 struct avtab_node *prev, *cur, *newnode;
126 int cmp;
127
128 if (!h || !h->nslot || h->nel == U32_MAX)
129 return -EINVAL;
130
131 hvalue = avtab_hash(key, h->mask);
132 for (prev = NULL, cur = h->htable[hvalue];
133 cur;
134 prev = cur, cur = cur->next) {
135 cmp = avtab_node_cmp(key, &cur->key);
136 /* extended perms may not be unique */
137 if (cmp == 0 && !(key->specified & AVTAB_XPERMS))
138 return -EEXIST;
139 if (cmp <= 0)
140 break;
141 }
142
143 newnode = avtab_insert_node(h, prev ? &prev->next : &h->htable[hvalue],
144 key, datum);
145 if (!newnode)
146 return -ENOMEM;
147
148 return 0;
149}
150
151/* Unlike avtab_insert(), this function allow multiple insertions of the same
152 * key/specified mask into the table, as needed by the conditional avtab.
153 * It also returns a pointer to the node inserted.
154 */
155struct avtab_node *avtab_insert_nonunique(struct avtab *h,
156 const struct avtab_key *key,
157 const struct avtab_datum *datum)
158{
159 u32 hvalue;
160 struct avtab_node *prev, *cur;
161 int cmp;
162
163 if (!h || !h->nslot || h->nel == U32_MAX)
164 return NULL;
165 hvalue = avtab_hash(key, h->mask);
166 for (prev = NULL, cur = h->htable[hvalue];
167 cur;
168 prev = cur, cur = cur->next) {
169 cmp = avtab_node_cmp(key, &cur->key);
170 if (cmp <= 0)
171 break;
172 }
173 return avtab_insert_node(h, prev ? &prev->next : &h->htable[hvalue],
174 key, datum);
175}
176
177/* This search function returns a node pointer, and can be used in
178 * conjunction with avtab_search_next_node()
179 */
180struct avtab_node *avtab_search_node(struct avtab *h,
181 const struct avtab_key *key)
182{
183 u32 hvalue;
184 struct avtab_node *cur;
185 int cmp;
186
187 if (!h || !h->nslot)
188 return NULL;
189
190 hvalue = avtab_hash(key, h->mask);
191 for (cur = h->htable[hvalue]; cur;
192 cur = cur->next) {
193 cmp = avtab_node_cmp(key, &cur->key);
194 if (cmp == 0)
195 return cur;
196 if (cmp < 0)
197 break;
198 }
199 return NULL;
200}
201
202struct avtab_node*
203avtab_search_node_next(struct avtab_node *node, u16 specified)
204{
205 struct avtab_key tmp_key;
206 struct avtab_node *cur;
207 int cmp;
208
209 if (!node)
210 return NULL;
211 tmp_key = node->key;
212 tmp_key.specified = specified;
213 for (cur = node->next; cur; cur = cur->next) {
214 cmp = avtab_node_cmp(&tmp_key, &cur->key);
215 if (cmp == 0)
216 return cur;
217 if (cmp < 0)
218 break;
219 }
220 return NULL;
221}
222
223void avtab_destroy(struct avtab *h)
224{
225 u32 i;
226 struct avtab_node *cur, *temp;
227
228 if (!h)
229 return;
230
231 for (i = 0; i < h->nslot; i++) {
232 cur = h->htable[i];
233 while (cur) {
234 temp = cur;
235 cur = cur->next;
236 if (temp->key.specified & AVTAB_XPERMS)
237 kmem_cache_free(avtab_xperms_cachep,
238 temp->datum.u.xperms);
239 kmem_cache_free(avtab_node_cachep, temp);
240 }
241 }
242 kvfree(h->htable);
243 h->htable = NULL;
244 h->nel = 0;
245 h->nslot = 0;
246 h->mask = 0;
247}
248
249void avtab_init(struct avtab *h)
250{
251 h->htable = NULL;
252 h->nel = 0;
253 h->nslot = 0;
254 h->mask = 0;
255}
256
257static int avtab_alloc_common(struct avtab *h, u32 nslot)
258{
259 if (!nslot)
260 return 0;
261
262 h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL);
263 if (!h->htable)
264 return -ENOMEM;
265
266 h->nslot = nslot;
267 h->mask = nslot - 1;
268 return 0;
269}
270
271int avtab_alloc(struct avtab *h, u32 nrules)
272{
273 int rc;
274 u32 nslot = 0;
275
276 if (nrules != 0) {
277 nslot = nrules > 3 ? rounddown_pow_of_two(nrules / 2) : 2;
278 if (nslot > MAX_AVTAB_HASH_BUCKETS)
279 nslot = MAX_AVTAB_HASH_BUCKETS;
280
281 rc = avtab_alloc_common(h, nslot);
282 if (rc)
283 return rc;
284 }
285
286 pr_debug("SELinux: %d avtab hash slots, %d rules.\n", nslot, nrules);
287 return 0;
288}
289
290int avtab_alloc_dup(struct avtab *new, const struct avtab *orig)
291{
292 return avtab_alloc_common(new, orig->nslot);
293}
294
295#ifdef CONFIG_SECURITY_SELINUX_DEBUG
296void avtab_hash_eval(struct avtab *h, const char *tag)
297{
298 u32 i, chain_len, slots_used, max_chain_len;
299 unsigned long long chain2_len_sum;
300 struct avtab_node *cur;
301
302 slots_used = 0;
303 max_chain_len = 0;
304 chain2_len_sum = 0;
305 for (i = 0; i < h->nslot; i++) {
306 cur = h->htable[i];
307 if (cur) {
308 slots_used++;
309 chain_len = 0;
310 while (cur) {
311 chain_len++;
312 cur = cur->next;
313 }
314
315 if (chain_len > max_chain_len)
316 max_chain_len = chain_len;
317 chain2_len_sum += (unsigned long long)chain_len * chain_len;
318 }
319 }
320
321 pr_debug("SELinux: %s: %d entries and %d/%d buckets used, "
322 "longest chain length %d, sum of chain length^2 %llu\n",
323 tag, h->nel, slots_used, h->nslot, max_chain_len,
324 chain2_len_sum);
325}
326#endif /* CONFIG_SECURITY_SELINUX_DEBUG */
327
328static const uint16_t spec_order[] = {
329 AVTAB_ALLOWED,
330 AVTAB_AUDITDENY,
331 AVTAB_AUDITALLOW,
332 AVTAB_TRANSITION,
333 AVTAB_CHANGE,
334 AVTAB_MEMBER,
335 AVTAB_XPERMS_ALLOWED,
336 AVTAB_XPERMS_AUDITALLOW,
337 AVTAB_XPERMS_DONTAUDIT
338};
339
340int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
341 int (*insertf)(struct avtab *a, const struct avtab_key *k,
342 const struct avtab_datum *d, void *p),
343 void *p)
344{
345 __le16 buf16[4];
346 u16 enabled;
347 u32 items, items2, val, i;
348 struct avtab_key key;
349 struct avtab_datum datum;
350 struct avtab_extended_perms xperms;
351 __le32 buf32[ARRAY_SIZE(xperms.perms.p)];
352 int rc;
353 unsigned int set, vers = pol->policyvers;
354
355 memset(&key, 0, sizeof(struct avtab_key));
356 memset(&datum, 0, sizeof(struct avtab_datum));
357
358 if (vers < POLICYDB_VERSION_AVTAB) {
359 rc = next_entry(buf32, fp, sizeof(u32));
360 if (rc) {
361 pr_err("SELinux: avtab: truncated entry\n");
362 return rc;
363 }
364 items2 = le32_to_cpu(buf32[0]);
365 if (items2 > ARRAY_SIZE(buf32)) {
366 pr_err("SELinux: avtab: entry overflow\n");
367 return -EINVAL;
368
369 }
370 rc = next_entry(buf32, fp, sizeof(u32)*items2);
371 if (rc) {
372 pr_err("SELinux: avtab: truncated entry\n");
373 return rc;
374 }
375 items = 0;
376
377 val = le32_to_cpu(buf32[items++]);
378 key.source_type = (u16)val;
379 if (key.source_type != val) {
380 pr_err("SELinux: avtab: truncated source type\n");
381 return -EINVAL;
382 }
383 val = le32_to_cpu(buf32[items++]);
384 key.target_type = (u16)val;
385 if (key.target_type != val) {
386 pr_err("SELinux: avtab: truncated target type\n");
387 return -EINVAL;
388 }
389 val = le32_to_cpu(buf32[items++]);
390 key.target_class = (u16)val;
391 if (key.target_class != val) {
392 pr_err("SELinux: avtab: truncated target class\n");
393 return -EINVAL;
394 }
395
396 val = le32_to_cpu(buf32[items++]);
397 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
398
399 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
400 pr_err("SELinux: avtab: null entry\n");
401 return -EINVAL;
402 }
403 if ((val & AVTAB_AV) &&
404 (val & AVTAB_TYPE)) {
405 pr_err("SELinux: avtab: entry has both access vectors and types\n");
406 return -EINVAL;
407 }
408 if (val & AVTAB_XPERMS) {
409 pr_err("SELinux: avtab: entry has extended permissions\n");
410 return -EINVAL;
411 }
412
413 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
414 if (val & spec_order[i]) {
415 key.specified = spec_order[i] | enabled;
416 datum.u.data = le32_to_cpu(buf32[items++]);
417 rc = insertf(a, &key, &datum, p);
418 if (rc)
419 return rc;
420 }
421 }
422
423 if (items != items2) {
424 pr_err("SELinux: avtab: entry only had %d items, expected %d\n",
425 items2, items);
426 return -EINVAL;
427 }
428 return 0;
429 }
430
431 rc = next_entry(buf16, fp, sizeof(u16)*4);
432 if (rc) {
433 pr_err("SELinux: avtab: truncated entry\n");
434 return rc;
435 }
436
437 items = 0;
438 key.source_type = le16_to_cpu(buf16[items++]);
439 key.target_type = le16_to_cpu(buf16[items++]);
440 key.target_class = le16_to_cpu(buf16[items++]);
441 key.specified = le16_to_cpu(buf16[items++]);
442
443 if (!policydb_type_isvalid(pol, key.source_type) ||
444 !policydb_type_isvalid(pol, key.target_type) ||
445 !policydb_class_isvalid(pol, key.target_class)) {
446 pr_err("SELinux: avtab: invalid type or class\n");
447 return -EINVAL;
448 }
449
450 set = hweight16(key.specified & (AVTAB_XPERMS | AVTAB_TYPE | AVTAB_AV));
451 if (!set || set > 1) {
452 pr_err("SELinux: avtab: more than one specifier\n");
453 return -EINVAL;
454 }
455
456 if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
457 (key.specified & AVTAB_XPERMS)) {
458 pr_err("SELinux: avtab: policy version %u does not "
459 "support extended permissions rules and one "
460 "was specified\n", vers);
461 return -EINVAL;
462 } else if (key.specified & AVTAB_XPERMS) {
463 memset(&xperms, 0, sizeof(struct avtab_extended_perms));
464 rc = next_entry(&xperms.specified, fp, sizeof(u8));
465 if (rc) {
466 pr_err("SELinux: avtab: truncated entry\n");
467 return rc;
468 }
469 rc = next_entry(&xperms.driver, fp, sizeof(u8));
470 if (rc) {
471 pr_err("SELinux: avtab: truncated entry\n");
472 return rc;
473 }
474 rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p));
475 if (rc) {
476 pr_err("SELinux: avtab: truncated entry\n");
477 return rc;
478 }
479 for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++)
480 xperms.perms.p[i] = le32_to_cpu(buf32[i]);
481 datum.u.xperms = &xperms;
482 } else {
483 rc = next_entry(buf32, fp, sizeof(u32));
484 if (rc) {
485 pr_err("SELinux: avtab: truncated entry\n");
486 return rc;
487 }
488 datum.u.data = le32_to_cpu(*buf32);
489 }
490 if ((key.specified & AVTAB_TYPE) &&
491 !policydb_type_isvalid(pol, datum.u.data)) {
492 pr_err("SELinux: avtab: invalid type\n");
493 return -EINVAL;
494 }
495 return insertf(a, &key, &datum, p);
496}
497
498static int avtab_insertf(struct avtab *a, const struct avtab_key *k,
499 const struct avtab_datum *d, void *p)
500{
501 return avtab_insert(a, k, d);
502}
503
504int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
505{
506 int rc;
507 __le32 buf[1];
508 u32 nel, i;
509
510
511 rc = next_entry(buf, fp, sizeof(u32));
512 if (rc < 0) {
513 pr_err("SELinux: avtab: truncated table\n");
514 goto bad;
515 }
516 nel = le32_to_cpu(buf[0]);
517 if (!nel) {
518 pr_err("SELinux: avtab: table is empty\n");
519 rc = -EINVAL;
520 goto bad;
521 }
522
523 rc = avtab_alloc(a, nel);
524 if (rc)
525 goto bad;
526
527 for (i = 0; i < nel; i++) {
528 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
529 if (rc) {
530 if (rc == -ENOMEM)
531 pr_err("SELinux: avtab: out of memory\n");
532 else if (rc == -EEXIST)
533 pr_err("SELinux: avtab: duplicate entry\n");
534
535 goto bad;
536 }
537 }
538
539 rc = 0;
540out:
541 return rc;
542
543bad:
544 avtab_destroy(a);
545 goto out;
546}
547
548int avtab_write_item(struct policydb *p, const struct avtab_node *cur, void *fp)
549{
550 __le16 buf16[4];
551 __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)];
552 int rc;
553 unsigned int i;
554
555 buf16[0] = cpu_to_le16(cur->key.source_type);
556 buf16[1] = cpu_to_le16(cur->key.target_type);
557 buf16[2] = cpu_to_le16(cur->key.target_class);
558 buf16[3] = cpu_to_le16(cur->key.specified);
559 rc = put_entry(buf16, sizeof(u16), 4, fp);
560 if (rc)
561 return rc;
562
563 if (cur->key.specified & AVTAB_XPERMS) {
564 rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp);
565 if (rc)
566 return rc;
567 rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp);
568 if (rc)
569 return rc;
570 for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++)
571 buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]);
572 rc = put_entry(buf32, sizeof(u32),
573 ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp);
574 } else {
575 buf32[0] = cpu_to_le32(cur->datum.u.data);
576 rc = put_entry(buf32, sizeof(u32), 1, fp);
577 }
578 if (rc)
579 return rc;
580 return 0;
581}
582
583int avtab_write(struct policydb *p, struct avtab *a, void *fp)
584{
585 u32 i;
586 int rc = 0;
587 struct avtab_node *cur;
588 __le32 buf[1];
589
590 buf[0] = cpu_to_le32(a->nel);
591 rc = put_entry(buf, sizeof(u32), 1, fp);
592 if (rc)
593 return rc;
594
595 for (i = 0; i < a->nslot; i++) {
596 for (cur = a->htable[i]; cur;
597 cur = cur->next) {
598 rc = avtab_write_item(p, cur, fp);
599 if (rc)
600 return rc;
601 }
602 }
603
604 return rc;
605}
606
607void __init avtab_cache_init(void)
608{
609 avtab_node_cachep = kmem_cache_create("avtab_node",
610 sizeof(struct avtab_node),
611 0, SLAB_PANIC, NULL);
612 avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms",
613 sizeof(struct avtab_extended_perms),
614 0, SLAB_PANIC, NULL);
615}