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1/*
2 * Implementation of the access vector table type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
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;
27
28static inline int avtab_hash(struct avtab_key *keyp, u16 mask)
29{
30 return ((keyp->target_class + (keyp->target_type << 2) +
31 (keyp->source_type << 9)) & mask);
32}
33
34static struct avtab_node*
35avtab_insert_node(struct avtab *h, int hvalue,
36 struct avtab_node *prev, struct avtab_node *cur,
37 struct avtab_key *key, struct avtab_datum *datum)
38{
39 struct avtab_node *newnode;
40 newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
41 if (newnode == NULL)
42 return NULL;
43 newnode->key = *key;
44 newnode->datum = *datum;
45 if (prev) {
46 newnode->next = prev->next;
47 prev->next = newnode;
48 } else {
49 newnode->next = h->htable[hvalue];
50 h->htable[hvalue] = newnode;
51 }
52
53 h->nel++;
54 return newnode;
55}
56
57static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
58{
59 int hvalue;
60 struct avtab_node *prev, *cur, *newnode;
61 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
62
63 if (!h || !h->htable)
64 return -EINVAL;
65
66 hvalue = avtab_hash(key, h->mask);
67 for (prev = NULL, cur = h->htable[hvalue];
68 cur;
69 prev = cur, cur = cur->next) {
70 if (key->source_type == cur->key.source_type &&
71 key->target_type == cur->key.target_type &&
72 key->target_class == cur->key.target_class &&
73 (specified & cur->key.specified))
74 return -EEXIST;
75 if (key->source_type < cur->key.source_type)
76 break;
77 if (key->source_type == cur->key.source_type &&
78 key->target_type < cur->key.target_type)
79 break;
80 if (key->source_type == cur->key.source_type &&
81 key->target_type == cur->key.target_type &&
82 key->target_class < cur->key.target_class)
83 break;
84 }
85
86 newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);
87 if (!newnode)
88 return -ENOMEM;
89
90 return 0;
91}
92
93/* Unlike avtab_insert(), this function allow multiple insertions of the same
94 * key/specified mask into the table, as needed by the conditional avtab.
95 * It also returns a pointer to the node inserted.
96 */
97struct avtab_node *
98avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
99{
100 int hvalue;
101 struct avtab_node *prev, *cur;
102 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
103
104 if (!h || !h->htable)
105 return NULL;
106 hvalue = avtab_hash(key, h->mask);
107 for (prev = NULL, cur = h->htable[hvalue];
108 cur;
109 prev = cur, cur = cur->next) {
110 if (key->source_type == cur->key.source_type &&
111 key->target_type == cur->key.target_type &&
112 key->target_class == cur->key.target_class &&
113 (specified & cur->key.specified))
114 break;
115 if (key->source_type < cur->key.source_type)
116 break;
117 if (key->source_type == cur->key.source_type &&
118 key->target_type < cur->key.target_type)
119 break;
120 if (key->source_type == cur->key.source_type &&
121 key->target_type == cur->key.target_type &&
122 key->target_class < cur->key.target_class)
123 break;
124 }
125 return avtab_insert_node(h, hvalue, prev, cur, key, datum);
126}
127
128struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
129{
130 int hvalue;
131 struct avtab_node *cur;
132 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
133
134 if (!h || !h->htable)
135 return NULL;
136
137 hvalue = avtab_hash(key, h->mask);
138 for (cur = h->htable[hvalue]; cur; cur = cur->next) {
139 if (key->source_type == cur->key.source_type &&
140 key->target_type == cur->key.target_type &&
141 key->target_class == cur->key.target_class &&
142 (specified & cur->key.specified))
143 return &cur->datum;
144
145 if (key->source_type < cur->key.source_type)
146 break;
147 if (key->source_type == cur->key.source_type &&
148 key->target_type < cur->key.target_type)
149 break;
150 if (key->source_type == cur->key.source_type &&
151 key->target_type == cur->key.target_type &&
152 key->target_class < cur->key.target_class)
153 break;
154 }
155
156 return NULL;
157}
158
159/* This search function returns a node pointer, and can be used in
160 * conjunction with avtab_search_next_node()
161 */
162struct avtab_node*
163avtab_search_node(struct avtab *h, struct avtab_key *key)
164{
165 int hvalue;
166 struct avtab_node *cur;
167 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
168
169 if (!h || !h->htable)
170 return NULL;
171
172 hvalue = avtab_hash(key, h->mask);
173 for (cur = h->htable[hvalue]; cur; cur = cur->next) {
174 if (key->source_type == cur->key.source_type &&
175 key->target_type == cur->key.target_type &&
176 key->target_class == cur->key.target_class &&
177 (specified & cur->key.specified))
178 return cur;
179
180 if (key->source_type < cur->key.source_type)
181 break;
182 if (key->source_type == cur->key.source_type &&
183 key->target_type < cur->key.target_type)
184 break;
185 if (key->source_type == cur->key.source_type &&
186 key->target_type == cur->key.target_type &&
187 key->target_class < cur->key.target_class)
188 break;
189 }
190 return NULL;
191}
192
193struct avtab_node*
194avtab_search_node_next(struct avtab_node *node, int specified)
195{
196 struct avtab_node *cur;
197
198 if (!node)
199 return NULL;
200
201 specified &= ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
202 for (cur = node->next; cur; cur = cur->next) {
203 if (node->key.source_type == cur->key.source_type &&
204 node->key.target_type == cur->key.target_type &&
205 node->key.target_class == cur->key.target_class &&
206 (specified & cur->key.specified))
207 return cur;
208
209 if (node->key.source_type < cur->key.source_type)
210 break;
211 if (node->key.source_type == cur->key.source_type &&
212 node->key.target_type < cur->key.target_type)
213 break;
214 if (node->key.source_type == cur->key.source_type &&
215 node->key.target_type == cur->key.target_type &&
216 node->key.target_class < cur->key.target_class)
217 break;
218 }
219 return NULL;
220}
221
222void avtab_destroy(struct avtab *h)
223{
224 int i;
225 struct avtab_node *cur, *temp;
226
227 if (!h || !h->htable)
228 return;
229
230 for (i = 0; i < h->nslot; i++) {
231 cur = h->htable[i];
232 while (cur) {
233 temp = cur;
234 cur = cur->next;
235 kmem_cache_free(avtab_node_cachep, temp);
236 }
237 h->htable[i] = NULL;
238 }
239 kfree(h->htable);
240 h->htable = NULL;
241 h->nslot = 0;
242 h->mask = 0;
243}
244
245int avtab_init(struct avtab *h)
246{
247 h->htable = NULL;
248 h->nel = 0;
249 return 0;
250}
251
252int avtab_alloc(struct avtab *h, u32 nrules)
253{
254 u16 mask = 0;
255 u32 shift = 0;
256 u32 work = nrules;
257 u32 nslot = 0;
258
259 if (nrules == 0)
260 goto avtab_alloc_out;
261
262 while (work) {
263 work = work >> 1;
264 shift++;
265 }
266 if (shift > 2)
267 shift = shift - 2;
268 nslot = 1 << shift;
269 if (nslot > MAX_AVTAB_HASH_BUCKETS)
270 nslot = MAX_AVTAB_HASH_BUCKETS;
271 mask = nslot - 1;
272
273 h->htable = kcalloc(nslot, sizeof(*(h->htable)), GFP_KERNEL);
274 if (!h->htable)
275 return -ENOMEM;
276
277 avtab_alloc_out:
278 h->nel = 0;
279 h->nslot = nslot;
280 h->mask = mask;
281 printk(KERN_DEBUG "SELinux: %d avtab hash slots, %d rules.\n",
282 h->nslot, nrules);
283 return 0;
284}
285
286void avtab_hash_eval(struct avtab *h, char *tag)
287{
288 int i, chain_len, slots_used, max_chain_len;
289 unsigned long long chain2_len_sum;
290 struct avtab_node *cur;
291
292 slots_used = 0;
293 max_chain_len = 0;
294 chain2_len_sum = 0;
295 for (i = 0; i < h->nslot; i++) {
296 cur = h->htable[i];
297 if (cur) {
298 slots_used++;
299 chain_len = 0;
300 while (cur) {
301 chain_len++;
302 cur = cur->next;
303 }
304
305 if (chain_len > max_chain_len)
306 max_chain_len = chain_len;
307 chain2_len_sum += chain_len * chain_len;
308 }
309 }
310
311 printk(KERN_DEBUG "SELinux: %s: %d entries and %d/%d buckets used, "
312 "longest chain length %d sum of chain length^2 %llu\n",
313 tag, h->nel, slots_used, h->nslot, max_chain_len,
314 chain2_len_sum);
315}
316
317static uint16_t spec_order[] = {
318 AVTAB_ALLOWED,
319 AVTAB_AUDITDENY,
320 AVTAB_AUDITALLOW,
321 AVTAB_TRANSITION,
322 AVTAB_CHANGE,
323 AVTAB_MEMBER
324};
325
326int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
327 int (*insertf)(struct avtab *a, struct avtab_key *k,
328 struct avtab_datum *d, void *p),
329 void *p)
330{
331 __le16 buf16[4];
332 u16 enabled;
333 __le32 buf32[7];
334 u32 items, items2, val, vers = pol->policyvers;
335 struct avtab_key key;
336 struct avtab_datum datum;
337 int i, rc;
338 unsigned set;
339
340 memset(&key, 0, sizeof(struct avtab_key));
341 memset(&datum, 0, sizeof(struct avtab_datum));
342
343 if (vers < POLICYDB_VERSION_AVTAB) {
344 rc = next_entry(buf32, fp, sizeof(u32));
345 if (rc) {
346 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
347 return rc;
348 }
349 items2 = le32_to_cpu(buf32[0]);
350 if (items2 > ARRAY_SIZE(buf32)) {
351 printk(KERN_ERR "SELinux: avtab: entry overflow\n");
352 return -EINVAL;
353
354 }
355 rc = next_entry(buf32, fp, sizeof(u32)*items2);
356 if (rc) {
357 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
358 return rc;
359 }
360 items = 0;
361
362 val = le32_to_cpu(buf32[items++]);
363 key.source_type = (u16)val;
364 if (key.source_type != val) {
365 printk(KERN_ERR "SELinux: avtab: truncated source type\n");
366 return -EINVAL;
367 }
368 val = le32_to_cpu(buf32[items++]);
369 key.target_type = (u16)val;
370 if (key.target_type != val) {
371 printk(KERN_ERR "SELinux: avtab: truncated target type\n");
372 return -EINVAL;
373 }
374 val = le32_to_cpu(buf32[items++]);
375 key.target_class = (u16)val;
376 if (key.target_class != val) {
377 printk(KERN_ERR "SELinux: avtab: truncated target class\n");
378 return -EINVAL;
379 }
380
381 val = le32_to_cpu(buf32[items++]);
382 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
383
384 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
385 printk(KERN_ERR "SELinux: avtab: null entry\n");
386 return -EINVAL;
387 }
388 if ((val & AVTAB_AV) &&
389 (val & AVTAB_TYPE)) {
390 printk(KERN_ERR "SELinux: avtab: entry has both access vectors and types\n");
391 return -EINVAL;
392 }
393
394 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
395 if (val & spec_order[i]) {
396 key.specified = spec_order[i] | enabled;
397 datum.data = le32_to_cpu(buf32[items++]);
398 rc = insertf(a, &key, &datum, p);
399 if (rc)
400 return rc;
401 }
402 }
403
404 if (items != items2) {
405 printk(KERN_ERR "SELinux: avtab: entry only had %d items, expected %d\n", items2, items);
406 return -EINVAL;
407 }
408 return 0;
409 }
410
411 rc = next_entry(buf16, fp, sizeof(u16)*4);
412 if (rc) {
413 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
414 return rc;
415 }
416
417 items = 0;
418 key.source_type = le16_to_cpu(buf16[items++]);
419 key.target_type = le16_to_cpu(buf16[items++]);
420 key.target_class = le16_to_cpu(buf16[items++]);
421 key.specified = le16_to_cpu(buf16[items++]);
422
423 if (!policydb_type_isvalid(pol, key.source_type) ||
424 !policydb_type_isvalid(pol, key.target_type) ||
425 !policydb_class_isvalid(pol, key.target_class)) {
426 printk(KERN_ERR "SELinux: avtab: invalid type or class\n");
427 return -EINVAL;
428 }
429
430 set = 0;
431 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
432 if (key.specified & spec_order[i])
433 set++;
434 }
435 if (!set || set > 1) {
436 printk(KERN_ERR "SELinux: avtab: more than one specifier\n");
437 return -EINVAL;
438 }
439
440 rc = next_entry(buf32, fp, sizeof(u32));
441 if (rc) {
442 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
443 return rc;
444 }
445 datum.data = le32_to_cpu(*buf32);
446 if ((key.specified & AVTAB_TYPE) &&
447 !policydb_type_isvalid(pol, datum.data)) {
448 printk(KERN_ERR "SELinux: avtab: invalid type\n");
449 return -EINVAL;
450 }
451 return insertf(a, &key, &datum, p);
452}
453
454static int avtab_insertf(struct avtab *a, struct avtab_key *k,
455 struct avtab_datum *d, void *p)
456{
457 return avtab_insert(a, k, d);
458}
459
460int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
461{
462 int rc;
463 __le32 buf[1];
464 u32 nel, i;
465
466
467 rc = next_entry(buf, fp, sizeof(u32));
468 if (rc < 0) {
469 printk(KERN_ERR "SELinux: avtab: truncated table\n");
470 goto bad;
471 }
472 nel = le32_to_cpu(buf[0]);
473 if (!nel) {
474 printk(KERN_ERR "SELinux: avtab: table is empty\n");
475 rc = -EINVAL;
476 goto bad;
477 }
478
479 rc = avtab_alloc(a, nel);
480 if (rc)
481 goto bad;
482
483 for (i = 0; i < nel; i++) {
484 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
485 if (rc) {
486 if (rc == -ENOMEM)
487 printk(KERN_ERR "SELinux: avtab: out of memory\n");
488 else if (rc == -EEXIST)
489 printk(KERN_ERR "SELinux: avtab: duplicate entry\n");
490
491 goto bad;
492 }
493 }
494
495 rc = 0;
496out:
497 return rc;
498
499bad:
500 avtab_destroy(a);
501 goto out;
502}
503
504int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
505{
506 __le16 buf16[4];
507 __le32 buf32[1];
508 int rc;
509
510 buf16[0] = cpu_to_le16(cur->key.source_type);
511 buf16[1] = cpu_to_le16(cur->key.target_type);
512 buf16[2] = cpu_to_le16(cur->key.target_class);
513 buf16[3] = cpu_to_le16(cur->key.specified);
514 rc = put_entry(buf16, sizeof(u16), 4, fp);
515 if (rc)
516 return rc;
517 buf32[0] = cpu_to_le32(cur->datum.data);
518 rc = put_entry(buf32, sizeof(u32), 1, fp);
519 if (rc)
520 return rc;
521 return 0;
522}
523
524int avtab_write(struct policydb *p, struct avtab *a, void *fp)
525{
526 unsigned int i;
527 int rc = 0;
528 struct avtab_node *cur;
529 __le32 buf[1];
530
531 buf[0] = cpu_to_le32(a->nel);
532 rc = put_entry(buf, sizeof(u32), 1, fp);
533 if (rc)
534 return rc;
535
536 for (i = 0; i < a->nslot; i++) {
537 for (cur = a->htable[i]; cur; cur = cur->next) {
538 rc = avtab_write_item(p, cur, fp);
539 if (rc)
540 return rc;
541 }
542 }
543
544 return rc;
545}
546void avtab_cache_init(void)
547{
548 avtab_node_cachep = kmem_cache_create("avtab_node",
549 sizeof(struct avtab_node),
550 0, SLAB_PANIC, NULL);
551}
552
553void avtab_cache_destroy(void)
554{
555 kmem_cache_destroy(avtab_node_cachep);
556}
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
302void avtab_init(struct avtab *h)
303{
304 kvfree(h->htable);
305 h->htable = NULL;
306 h->nel = 0;
307}
308
309int avtab_alloc(struct avtab *h, u32 nrules)
310{
311 u32 mask = 0;
312 u32 shift = 0;
313 u32 work = nrules;
314 u32 nslot = 0;
315
316 if (nrules == 0)
317 goto avtab_alloc_out;
318
319 while (work) {
320 work = work >> 1;
321 shift++;
322 }
323 if (shift > 2)
324 shift = shift - 2;
325 nslot = 1 << shift;
326 if (nslot > MAX_AVTAB_HASH_BUCKETS)
327 nslot = MAX_AVTAB_HASH_BUCKETS;
328 mask = nslot - 1;
329
330 h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL);
331 if (!h->htable)
332 return -ENOMEM;
333
334 avtab_alloc_out:
335 h->nel = 0;
336 h->nslot = nslot;
337 h->mask = mask;
338 pr_debug("SELinux: %d avtab hash slots, %d rules.\n",
339 h->nslot, nrules);
340 return 0;
341}
342
343void avtab_hash_eval(struct avtab *h, char *tag)
344{
345 int i, chain_len, slots_used, max_chain_len;
346 unsigned long long chain2_len_sum;
347 struct avtab_node *cur;
348
349 slots_used = 0;
350 max_chain_len = 0;
351 chain2_len_sum = 0;
352 for (i = 0; i < h->nslot; i++) {
353 cur = h->htable[i];
354 if (cur) {
355 slots_used++;
356 chain_len = 0;
357 while (cur) {
358 chain_len++;
359 cur = cur->next;
360 }
361
362 if (chain_len > max_chain_len)
363 max_chain_len = chain_len;
364 chain2_len_sum += chain_len * chain_len;
365 }
366 }
367
368 pr_debug("SELinux: %s: %d entries and %d/%d buckets used, "
369 "longest chain length %d sum of chain length^2 %llu\n",
370 tag, h->nel, slots_used, h->nslot, max_chain_len,
371 chain2_len_sum);
372}
373
374static uint16_t spec_order[] = {
375 AVTAB_ALLOWED,
376 AVTAB_AUDITDENY,
377 AVTAB_AUDITALLOW,
378 AVTAB_TRANSITION,
379 AVTAB_CHANGE,
380 AVTAB_MEMBER,
381 AVTAB_XPERMS_ALLOWED,
382 AVTAB_XPERMS_AUDITALLOW,
383 AVTAB_XPERMS_DONTAUDIT
384};
385
386int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
387 int (*insertf)(struct avtab *a, struct avtab_key *k,
388 struct avtab_datum *d, void *p),
389 void *p)
390{
391 __le16 buf16[4];
392 u16 enabled;
393 u32 items, items2, val, vers = pol->policyvers;
394 struct avtab_key key;
395 struct avtab_datum datum;
396 struct avtab_extended_perms xperms;
397 __le32 buf32[ARRAY_SIZE(xperms.perms.p)];
398 int i, rc;
399 unsigned set;
400
401 memset(&key, 0, sizeof(struct avtab_key));
402 memset(&datum, 0, sizeof(struct avtab_datum));
403
404 if (vers < POLICYDB_VERSION_AVTAB) {
405 rc = next_entry(buf32, fp, sizeof(u32));
406 if (rc) {
407 pr_err("SELinux: avtab: truncated entry\n");
408 return rc;
409 }
410 items2 = le32_to_cpu(buf32[0]);
411 if (items2 > ARRAY_SIZE(buf32)) {
412 pr_err("SELinux: avtab: entry overflow\n");
413 return -EINVAL;
414
415 }
416 rc = next_entry(buf32, fp, sizeof(u32)*items2);
417 if (rc) {
418 pr_err("SELinux: avtab: truncated entry\n");
419 return rc;
420 }
421 items = 0;
422
423 val = le32_to_cpu(buf32[items++]);
424 key.source_type = (u16)val;
425 if (key.source_type != val) {
426 pr_err("SELinux: avtab: truncated source type\n");
427 return -EINVAL;
428 }
429 val = le32_to_cpu(buf32[items++]);
430 key.target_type = (u16)val;
431 if (key.target_type != val) {
432 pr_err("SELinux: avtab: truncated target type\n");
433 return -EINVAL;
434 }
435 val = le32_to_cpu(buf32[items++]);
436 key.target_class = (u16)val;
437 if (key.target_class != val) {
438 pr_err("SELinux: avtab: truncated target class\n");
439 return -EINVAL;
440 }
441
442 val = le32_to_cpu(buf32[items++]);
443 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
444
445 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
446 pr_err("SELinux: avtab: null entry\n");
447 return -EINVAL;
448 }
449 if ((val & AVTAB_AV) &&
450 (val & AVTAB_TYPE)) {
451 pr_err("SELinux: avtab: entry has both access vectors and types\n");
452 return -EINVAL;
453 }
454 if (val & AVTAB_XPERMS) {
455 pr_err("SELinux: avtab: entry has extended permissions\n");
456 return -EINVAL;
457 }
458
459 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
460 if (val & spec_order[i]) {
461 key.specified = spec_order[i] | enabled;
462 datum.u.data = le32_to_cpu(buf32[items++]);
463 rc = insertf(a, &key, &datum, p);
464 if (rc)
465 return rc;
466 }
467 }
468
469 if (items != items2) {
470 pr_err("SELinux: avtab: entry only had %d items, expected %d\n",
471 items2, items);
472 return -EINVAL;
473 }
474 return 0;
475 }
476
477 rc = next_entry(buf16, fp, sizeof(u16)*4);
478 if (rc) {
479 pr_err("SELinux: avtab: truncated entry\n");
480 return rc;
481 }
482
483 items = 0;
484 key.source_type = le16_to_cpu(buf16[items++]);
485 key.target_type = le16_to_cpu(buf16[items++]);
486 key.target_class = le16_to_cpu(buf16[items++]);
487 key.specified = le16_to_cpu(buf16[items++]);
488
489 if (!policydb_type_isvalid(pol, key.source_type) ||
490 !policydb_type_isvalid(pol, key.target_type) ||
491 !policydb_class_isvalid(pol, key.target_class)) {
492 pr_err("SELinux: avtab: invalid type or class\n");
493 return -EINVAL;
494 }
495
496 set = 0;
497 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
498 if (key.specified & spec_order[i])
499 set++;
500 }
501 if (!set || set > 1) {
502 pr_err("SELinux: avtab: more than one specifier\n");
503 return -EINVAL;
504 }
505
506 if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
507 (key.specified & AVTAB_XPERMS)) {
508 pr_err("SELinux: avtab: policy version %u does not "
509 "support extended permissions rules and one "
510 "was specified\n", vers);
511 return -EINVAL;
512 } else if (key.specified & AVTAB_XPERMS) {
513 memset(&xperms, 0, sizeof(struct avtab_extended_perms));
514 rc = next_entry(&xperms.specified, fp, sizeof(u8));
515 if (rc) {
516 pr_err("SELinux: avtab: truncated entry\n");
517 return rc;
518 }
519 rc = next_entry(&xperms.driver, fp, sizeof(u8));
520 if (rc) {
521 pr_err("SELinux: avtab: truncated entry\n");
522 return rc;
523 }
524 rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p));
525 if (rc) {
526 pr_err("SELinux: avtab: truncated entry\n");
527 return rc;
528 }
529 for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++)
530 xperms.perms.p[i] = le32_to_cpu(buf32[i]);
531 datum.u.xperms = &xperms;
532 } else {
533 rc = next_entry(buf32, fp, sizeof(u32));
534 if (rc) {
535 pr_err("SELinux: avtab: truncated entry\n");
536 return rc;
537 }
538 datum.u.data = le32_to_cpu(*buf32);
539 }
540 if ((key.specified & AVTAB_TYPE) &&
541 !policydb_type_isvalid(pol, datum.u.data)) {
542 pr_err("SELinux: avtab: invalid type\n");
543 return -EINVAL;
544 }
545 return insertf(a, &key, &datum, p);
546}
547
548static int avtab_insertf(struct avtab *a, struct avtab_key *k,
549 struct avtab_datum *d, void *p)
550{
551 return avtab_insert(a, k, d);
552}
553
554int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
555{
556 int rc;
557 __le32 buf[1];
558 u32 nel, i;
559
560
561 rc = next_entry(buf, fp, sizeof(u32));
562 if (rc < 0) {
563 pr_err("SELinux: avtab: truncated table\n");
564 goto bad;
565 }
566 nel = le32_to_cpu(buf[0]);
567 if (!nel) {
568 pr_err("SELinux: avtab: table is empty\n");
569 rc = -EINVAL;
570 goto bad;
571 }
572
573 rc = avtab_alloc(a, nel);
574 if (rc)
575 goto bad;
576
577 for (i = 0; i < nel; i++) {
578 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
579 if (rc) {
580 if (rc == -ENOMEM)
581 pr_err("SELinux: avtab: out of memory\n");
582 else if (rc == -EEXIST)
583 pr_err("SELinux: avtab: duplicate entry\n");
584
585 goto bad;
586 }
587 }
588
589 rc = 0;
590out:
591 return rc;
592
593bad:
594 avtab_destroy(a);
595 goto out;
596}
597
598int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
599{
600 __le16 buf16[4];
601 __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)];
602 int rc;
603 unsigned int i;
604
605 buf16[0] = cpu_to_le16(cur->key.source_type);
606 buf16[1] = cpu_to_le16(cur->key.target_type);
607 buf16[2] = cpu_to_le16(cur->key.target_class);
608 buf16[3] = cpu_to_le16(cur->key.specified);
609 rc = put_entry(buf16, sizeof(u16), 4, fp);
610 if (rc)
611 return rc;
612
613 if (cur->key.specified & AVTAB_XPERMS) {
614 rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp);
615 if (rc)
616 return rc;
617 rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp);
618 if (rc)
619 return rc;
620 for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++)
621 buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]);
622 rc = put_entry(buf32, sizeof(u32),
623 ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp);
624 } else {
625 buf32[0] = cpu_to_le32(cur->datum.u.data);
626 rc = put_entry(buf32, sizeof(u32), 1, fp);
627 }
628 if (rc)
629 return rc;
630 return 0;
631}
632
633int avtab_write(struct policydb *p, struct avtab *a, void *fp)
634{
635 unsigned int i;
636 int rc = 0;
637 struct avtab_node *cur;
638 __le32 buf[1];
639
640 buf[0] = cpu_to_le32(a->nel);
641 rc = put_entry(buf, sizeof(u32), 1, fp);
642 if (rc)
643 return rc;
644
645 for (i = 0; i < a->nslot; i++) {
646 for (cur = a->htable[i]; cur;
647 cur = cur->next) {
648 rc = avtab_write_item(p, cur, fp);
649 if (rc)
650 return rc;
651 }
652 }
653
654 return rc;
655}
656
657void __init avtab_cache_init(void)
658{
659 avtab_node_cachep = kmem_cache_create("avtab_node",
660 sizeof(struct avtab_node),
661 0, SLAB_PANIC, NULL);
662 avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms",
663 sizeof(struct avtab_extended_perms),
664 0, SLAB_PANIC, NULL);
665}