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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;
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
94
95
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
160
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_SIZE)
270 nslot = MAX_AVTAB_SIZE;
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 < 0) {
346 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
347 return -1;
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 -1;
353
354 }
355 rc = next_entry(buf32, fp, sizeof(u32)*items2);
356 if (rc < 0) {
357 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
358 return -1;
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 -1;
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 -1;
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 -1;
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 -1;
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 -1;
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 -1;
407 }
408 return 0;
409 }
410
411 rc = next_entry(buf16, fp, sizeof(u16)*4);
412 if (rc < 0) {
413 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
414 return -1;
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 -1;
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 -1;
438 }
439
440 rc = next_entry(buf32, fp, sizeof(u32));
441 if (rc < 0) {
442 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
443 return -1;
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 -1;
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 else
491 rc = -EINVAL;
492 goto bad;
493 }
494 }
495
496 rc = 0;
497out:
498 return rc;
499
500bad:
501 avtab_destroy(a);
502 goto out;
503}
504
505void avtab_cache_init(void)
506{
507 avtab_node_cachep = kmem_cache_create("avtab_node",
508 sizeof(struct avtab_node),
509 0, SLAB_PANIC, NULL);
510}
511
512void avtab_cache_destroy(void)
513{
514 kmem_cache_destroy(avtab_node_cachep);
515}
516
