2 * Implementation of the access vector table type.
4 * Author : Stephen Smalley, <sds@tycho.nsa.gov>
7 /* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
9 * Added conditional policy language extensions
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.
16 * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
17 * Tuned number of hash slots for avtab to reduce memory usage
20 #include <linux/kernel.h>
21 #include <linux/slab.h>
22 #include <linux/errno.h>
26 static struct kmem_cache *avtab_node_cachep __ro_after_init;
27 static struct kmem_cache *avtab_xperms_cachep __ro_after_init;
29 /* Based on MurmurHash3, written by Austin Appleby and placed in the
32 static inline int avtab_hash(const struct avtab_key *keyp, u32 mask)
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;
43 #define mix(input) { \
46 v = (v << r1) | (v >> (32 - r1)); \
49 hash = (hash << r2) | (hash >> (32 - r2)); \
50 hash = hash * m + n; \
53 mix(keyp->target_class);
54 mix(keyp->target_type);
55 mix(keyp->source_type);
68 static struct avtab_node*
69 avtab_insert_node(struct avtab *h, int hvalue,
70 struct avtab_node *prev,
71 const struct avtab_key *key, const struct avtab_datum *datum)
73 struct avtab_node *newnode;
74 struct avtab_extended_perms *xperms;
75 newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
80 if (key->specified & AVTAB_XPERMS) {
81 xperms = kmem_cache_zalloc(avtab_xperms_cachep, GFP_KERNEL);
83 kmem_cache_free(avtab_node_cachep, newnode);
86 *xperms = *(datum->u.xperms);
87 newnode->datum.u.xperms = xperms;
89 newnode->datum.u.data = datum->u.data;
93 newnode->next = prev->next;
96 struct avtab_node **n = &h->htable[hvalue];
106 static int avtab_insert(struct avtab *h, const struct avtab_key *key,
107 const struct avtab_datum *datum)
110 struct avtab_node *prev, *cur, *newnode;
111 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
116 hvalue = avtab_hash(key, h->mask);
117 for (prev = NULL, cur = h->htable[hvalue];
119 prev = cur, cur = cur->next) {
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 (specified & cur->key.specified)) {
124 /* extended perms may not be unique */
125 if (specified & AVTAB_XPERMS)
129 if (key->source_type < cur->key.source_type)
131 if (key->source_type == cur->key.source_type &&
132 key->target_type < cur->key.target_type)
134 if (key->source_type == cur->key.source_type &&
135 key->target_type == cur->key.target_type &&
136 key->target_class < cur->key.target_class)
140 newnode = avtab_insert_node(h, hvalue, prev, key, datum);
147 /* Unlike avtab_insert(), this function allow multiple insertions of the same
148 * key/specified mask into the table, as needed by the conditional avtab.
149 * It also returns a pointer to the node inserted.
151 struct avtab_node *avtab_insert_nonunique(struct avtab *h,
152 const struct avtab_key *key,
153 const struct avtab_datum *datum)
156 struct avtab_node *prev, *cur;
157 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
161 hvalue = avtab_hash(key, h->mask);
162 for (prev = NULL, cur = h->htable[hvalue];
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))
170 if (key->source_type < cur->key.source_type)
172 if (key->source_type == cur->key.source_type &&
173 key->target_type < cur->key.target_type)
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)
180 return avtab_insert_node(h, hvalue, prev, key, datum);
183 struct avtab_datum *avtab_search(struct avtab *h, const struct avtab_key *key)
186 struct avtab_node *cur;
187 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
192 hvalue = avtab_hash(key, h->mask);
193 for (cur = h->htable[hvalue]; cur;
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))
201 if (key->source_type < cur->key.source_type)
203 if (key->source_type == cur->key.source_type &&
204 key->target_type < cur->key.target_type)
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)
215 /* This search function returns a node pointer, and can be used in
216 * conjunction with avtab_search_next_node()
218 struct avtab_node *avtab_search_node(struct avtab *h,
219 const struct avtab_key *key)
222 struct avtab_node *cur;
223 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
228 hvalue = avtab_hash(key, h->mask);
229 for (cur = h->htable[hvalue]; cur;
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))
237 if (key->source_type < cur->key.source_type)
239 if (key->source_type == cur->key.source_type &&
240 key->target_type < cur->key.target_type)
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)
251 avtab_search_node_next(struct avtab_node *node, int specified)
253 struct avtab_node *cur;
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))
266 if (node->key.source_type < cur->key.source_type)
268 if (node->key.source_type == cur->key.source_type &&
269 node->key.target_type < cur->key.target_type)
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)
279 void avtab_destroy(struct avtab *h)
282 struct avtab_node *cur, *temp;
287 for (i = 0; i < h->nslot; i++) {
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);
305 void avtab_init(struct avtab *h)
313 static int avtab_alloc_common(struct avtab *h, u32 nslot)
318 h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL);
327 int avtab_alloc(struct avtab *h, u32 nrules)
334 u32 work = nrules >> 3;
340 if (nslot > MAX_AVTAB_HASH_BUCKETS)
341 nslot = MAX_AVTAB_HASH_BUCKETS;
343 rc = avtab_alloc_common(h, nslot);
348 pr_debug("SELinux: %d avtab hash slots, %d rules.\n", nslot, nrules);
352 int avtab_alloc_dup(struct avtab *new, const struct avtab *orig)
354 return avtab_alloc_common(new, orig->nslot);
357 void avtab_hash_eval(struct avtab *h, char *tag)
359 int i, chain_len, slots_used, max_chain_len;
360 unsigned long long chain2_len_sum;
361 struct avtab_node *cur;
366 for (i = 0; i < h->nslot; i++) {
376 if (chain_len > max_chain_len)
377 max_chain_len = chain_len;
378 chain2_len_sum += chain_len * chain_len;
382 pr_debug("SELinux: %s: %d entries and %d/%d buckets used, "
383 "longest chain length %d sum of chain length^2 %llu\n",
384 tag, h->nel, slots_used, h->nslot, max_chain_len,
388 static uint16_t spec_order[] = {
395 AVTAB_XPERMS_ALLOWED,
396 AVTAB_XPERMS_AUDITALLOW,
397 AVTAB_XPERMS_DONTAUDIT
400 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
401 int (*insertf)(struct avtab *a, const struct avtab_key *k,
402 const struct avtab_datum *d, void *p),
407 u32 items, items2, val, vers = pol->policyvers;
408 struct avtab_key key;
409 struct avtab_datum datum;
410 struct avtab_extended_perms xperms;
411 __le32 buf32[ARRAY_SIZE(xperms.perms.p)];
415 memset(&key, 0, sizeof(struct avtab_key));
416 memset(&datum, 0, sizeof(struct avtab_datum));
418 if (vers < POLICYDB_VERSION_AVTAB) {
419 rc = next_entry(buf32, fp, sizeof(u32));
421 pr_err("SELinux: avtab: truncated entry\n");
424 items2 = le32_to_cpu(buf32[0]);
425 if (items2 > ARRAY_SIZE(buf32)) {
426 pr_err("SELinux: avtab: entry overflow\n");
430 rc = next_entry(buf32, fp, sizeof(u32)*items2);
432 pr_err("SELinux: avtab: truncated entry\n");
437 val = le32_to_cpu(buf32[items++]);
438 key.source_type = (u16)val;
439 if (key.source_type != val) {
440 pr_err("SELinux: avtab: truncated source type\n");
443 val = le32_to_cpu(buf32[items++]);
444 key.target_type = (u16)val;
445 if (key.target_type != val) {
446 pr_err("SELinux: avtab: truncated target type\n");
449 val = le32_to_cpu(buf32[items++]);
450 key.target_class = (u16)val;
451 if (key.target_class != val) {
452 pr_err("SELinux: avtab: truncated target class\n");
456 val = le32_to_cpu(buf32[items++]);
457 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
459 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
460 pr_err("SELinux: avtab: null entry\n");
463 if ((val & AVTAB_AV) &&
464 (val & AVTAB_TYPE)) {
465 pr_err("SELinux: avtab: entry has both access vectors and types\n");
468 if (val & AVTAB_XPERMS) {
469 pr_err("SELinux: avtab: entry has extended permissions\n");
473 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
474 if (val & spec_order[i]) {
475 key.specified = spec_order[i] | enabled;
476 datum.u.data = le32_to_cpu(buf32[items++]);
477 rc = insertf(a, &key, &datum, p);
483 if (items != items2) {
484 pr_err("SELinux: avtab: entry only had %d items, expected %d\n",
491 rc = next_entry(buf16, fp, sizeof(u16)*4);
493 pr_err("SELinux: avtab: truncated entry\n");
498 key.source_type = le16_to_cpu(buf16[items++]);
499 key.target_type = le16_to_cpu(buf16[items++]);
500 key.target_class = le16_to_cpu(buf16[items++]);
501 key.specified = le16_to_cpu(buf16[items++]);
503 if (!policydb_type_isvalid(pol, key.source_type) ||
504 !policydb_type_isvalid(pol, key.target_type) ||
505 !policydb_class_isvalid(pol, key.target_class)) {
506 pr_err("SELinux: avtab: invalid type or class\n");
511 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
512 if (key.specified & spec_order[i])
515 if (!set || set > 1) {
516 pr_err("SELinux: avtab: more than one specifier\n");
520 if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
521 (key.specified & AVTAB_XPERMS)) {
522 pr_err("SELinux: avtab: policy version %u does not "
523 "support extended permissions rules and one "
524 "was specified\n", vers);
526 } else if (key.specified & AVTAB_XPERMS) {
527 memset(&xperms, 0, sizeof(struct avtab_extended_perms));
528 rc = next_entry(&xperms.specified, fp, sizeof(u8));
530 pr_err("SELinux: avtab: truncated entry\n");
533 rc = next_entry(&xperms.driver, fp, sizeof(u8));
535 pr_err("SELinux: avtab: truncated entry\n");
538 rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p));
540 pr_err("SELinux: avtab: truncated entry\n");
543 for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++)
544 xperms.perms.p[i] = le32_to_cpu(buf32[i]);
545 datum.u.xperms = &xperms;
547 rc = next_entry(buf32, fp, sizeof(u32));
549 pr_err("SELinux: avtab: truncated entry\n");
552 datum.u.data = le32_to_cpu(*buf32);
554 if ((key.specified & AVTAB_TYPE) &&
555 !policydb_type_isvalid(pol, datum.u.data)) {
556 pr_err("SELinux: avtab: invalid type\n");
559 return insertf(a, &key, &datum, p);
562 static int avtab_insertf(struct avtab *a, const struct avtab_key *k,
563 const struct avtab_datum *d, void *p)
565 return avtab_insert(a, k, d);
568 int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
575 rc = next_entry(buf, fp, sizeof(u32));
577 pr_err("SELinux: avtab: truncated table\n");
580 nel = le32_to_cpu(buf[0]);
582 pr_err("SELinux: avtab: table is empty\n");
587 rc = avtab_alloc(a, nel);
591 for (i = 0; i < nel; i++) {
592 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
595 pr_err("SELinux: avtab: out of memory\n");
596 else if (rc == -EEXIST)
597 pr_err("SELinux: avtab: duplicate entry\n");
612 int avtab_write_item(struct policydb *p, const struct avtab_node *cur, void *fp)
615 __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)];
619 buf16[0] = cpu_to_le16(cur->key.source_type);
620 buf16[1] = cpu_to_le16(cur->key.target_type);
621 buf16[2] = cpu_to_le16(cur->key.target_class);
622 buf16[3] = cpu_to_le16(cur->key.specified);
623 rc = put_entry(buf16, sizeof(u16), 4, fp);
627 if (cur->key.specified & AVTAB_XPERMS) {
628 rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp);
631 rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp);
634 for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++)
635 buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]);
636 rc = put_entry(buf32, sizeof(u32),
637 ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp);
639 buf32[0] = cpu_to_le32(cur->datum.u.data);
640 rc = put_entry(buf32, sizeof(u32), 1, fp);
647 int avtab_write(struct policydb *p, struct avtab *a, void *fp)
651 struct avtab_node *cur;
654 buf[0] = cpu_to_le32(a->nel);
655 rc = put_entry(buf, sizeof(u32), 1, fp);
659 for (i = 0; i < a->nslot; i++) {
660 for (cur = a->htable[i]; cur;
662 rc = avtab_write_item(p, cur, fp);
671 void __init avtab_cache_init(void)
673 avtab_node_cachep = kmem_cache_create("avtab_node",
674 sizeof(struct avtab_node),
675 0, SLAB_PANIC, NULL);
676 avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms",
677 sizeof(struct avtab_extended_perms),
678 0, SLAB_PANIC, NULL);