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(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, struct avtab_node *cur,
71 struct avtab_key *key, 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, struct avtab_key *key, struct avtab_datum *datum)
109 struct avtab_node *prev, *cur, *newnode;
110 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
115 hvalue = avtab_hash(key, h->mask);
116 for (prev = NULL, cur = h->htable[hvalue];
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)
128 if (key->source_type < cur->key.source_type)
130 if (key->source_type == cur->key.source_type &&
131 key->target_type < cur->key.target_type)
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)
139 newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);
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.
151 avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
154 struct avtab_node *prev, *cur;
155 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
159 hvalue = avtab_hash(key, h->mask);
160 for (prev = NULL, cur = h->htable[hvalue];
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))
168 if (key->source_type < cur->key.source_type)
170 if (key->source_type == cur->key.source_type &&
171 key->target_type < cur->key.target_type)
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)
178 return avtab_insert_node(h, hvalue, prev, cur, key, datum);
181 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
184 struct avtab_node *cur;
185 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
190 hvalue = avtab_hash(key, h->mask);
191 for (cur = h->htable[hvalue]; cur;
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))
199 if (key->source_type < cur->key.source_type)
201 if (key->source_type == cur->key.source_type &&
202 key->target_type < cur->key.target_type)
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)
213 /* This search function returns a node pointer, and can be used in
214 * conjunction with avtab_search_next_node()
217 avtab_search_node(struct avtab *h, struct avtab_key *key)
220 struct avtab_node *cur;
221 u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
226 hvalue = avtab_hash(key, h->mask);
227 for (cur = h->htable[hvalue]; cur;
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))
235 if (key->source_type < cur->key.source_type)
237 if (key->source_type == cur->key.source_type &&
238 key->target_type < cur->key.target_type)
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)
249 avtab_search_node_next(struct avtab_node *node, int specified)
251 struct avtab_node *cur;
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))
264 if (node->key.source_type < cur->key.source_type)
266 if (node->key.source_type == cur->key.source_type &&
267 node->key.target_type < cur->key.target_type)
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)
277 void avtab_destroy(struct avtab *h)
280 struct avtab_node *cur, *temp;
285 for (i = 0; i < h->nslot; i++) {
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);
303 void avtab_init(struct avtab *h)
311 static int avtab_alloc_common(struct avtab *h, u32 nslot)
316 h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL);
325 int avtab_alloc(struct avtab *h, u32 nrules)
332 u32 work = nrules >> 3;
338 if (nslot > MAX_AVTAB_HASH_BUCKETS)
339 nslot = MAX_AVTAB_HASH_BUCKETS;
341 rc = avtab_alloc_common(h, nslot);
346 pr_debug("SELinux: %d avtab hash slots, %d rules.\n", nslot, nrules);
350 int avtab_alloc_dup(struct avtab *new, const struct avtab *orig)
352 return avtab_alloc_common(new, orig->nslot);
355 void avtab_hash_eval(struct avtab *h, char *tag)
357 int i, chain_len, slots_used, max_chain_len;
358 unsigned long long chain2_len_sum;
359 struct avtab_node *cur;
364 for (i = 0; i < h->nslot; i++) {
374 if (chain_len > max_chain_len)
375 max_chain_len = chain_len;
376 chain2_len_sum += chain_len * chain_len;
380 pr_debug("SELinux: %s: %d entries and %d/%d buckets used, "
381 "longest chain length %d sum of chain length^2 %llu\n",
382 tag, h->nel, slots_used, h->nslot, max_chain_len,
386 static uint16_t spec_order[] = {
393 AVTAB_XPERMS_ALLOWED,
394 AVTAB_XPERMS_AUDITALLOW,
395 AVTAB_XPERMS_DONTAUDIT
398 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
399 int (*insertf)(struct avtab *a, struct avtab_key *k,
400 struct avtab_datum *d, void *p),
405 u32 items, items2, val, vers = pol->policyvers;
406 struct avtab_key key;
407 struct avtab_datum datum;
408 struct avtab_extended_perms xperms;
409 __le32 buf32[ARRAY_SIZE(xperms.perms.p)];
413 memset(&key, 0, sizeof(struct avtab_key));
414 memset(&datum, 0, sizeof(struct avtab_datum));
416 if (vers < POLICYDB_VERSION_AVTAB) {
417 rc = next_entry(buf32, fp, sizeof(u32));
419 pr_err("SELinux: avtab: truncated entry\n");
422 items2 = le32_to_cpu(buf32[0]);
423 if (items2 > ARRAY_SIZE(buf32)) {
424 pr_err("SELinux: avtab: entry overflow\n");
428 rc = next_entry(buf32, fp, sizeof(u32)*items2);
430 pr_err("SELinux: avtab: truncated entry\n");
435 val = le32_to_cpu(buf32[items++]);
436 key.source_type = (u16)val;
437 if (key.source_type != val) {
438 pr_err("SELinux: avtab: truncated source type\n");
441 val = le32_to_cpu(buf32[items++]);
442 key.target_type = (u16)val;
443 if (key.target_type != val) {
444 pr_err("SELinux: avtab: truncated target type\n");
447 val = le32_to_cpu(buf32[items++]);
448 key.target_class = (u16)val;
449 if (key.target_class != val) {
450 pr_err("SELinux: avtab: truncated target class\n");
454 val = le32_to_cpu(buf32[items++]);
455 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
457 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
458 pr_err("SELinux: avtab: null entry\n");
461 if ((val & AVTAB_AV) &&
462 (val & AVTAB_TYPE)) {
463 pr_err("SELinux: avtab: entry has both access vectors and types\n");
466 if (val & AVTAB_XPERMS) {
467 pr_err("SELinux: avtab: entry has extended permissions\n");
471 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
472 if (val & spec_order[i]) {
473 key.specified = spec_order[i] | enabled;
474 datum.u.data = le32_to_cpu(buf32[items++]);
475 rc = insertf(a, &key, &datum, p);
481 if (items != items2) {
482 pr_err("SELinux: avtab: entry only had %d items, expected %d\n",
489 rc = next_entry(buf16, fp, sizeof(u16)*4);
491 pr_err("SELinux: avtab: truncated entry\n");
496 key.source_type = le16_to_cpu(buf16[items++]);
497 key.target_type = le16_to_cpu(buf16[items++]);
498 key.target_class = le16_to_cpu(buf16[items++]);
499 key.specified = le16_to_cpu(buf16[items++]);
501 if (!policydb_type_isvalid(pol, key.source_type) ||
502 !policydb_type_isvalid(pol, key.target_type) ||
503 !policydb_class_isvalid(pol, key.target_class)) {
504 pr_err("SELinux: avtab: invalid type or class\n");
509 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
510 if (key.specified & spec_order[i])
513 if (!set || set > 1) {
514 pr_err("SELinux: avtab: more than one specifier\n");
518 if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
519 (key.specified & AVTAB_XPERMS)) {
520 pr_err("SELinux: avtab: policy version %u does not "
521 "support extended permissions rules and one "
522 "was specified\n", vers);
524 } else if (key.specified & AVTAB_XPERMS) {
525 memset(&xperms, 0, sizeof(struct avtab_extended_perms));
526 rc = next_entry(&xperms.specified, fp, sizeof(u8));
528 pr_err("SELinux: avtab: truncated entry\n");
531 rc = next_entry(&xperms.driver, fp, sizeof(u8));
533 pr_err("SELinux: avtab: truncated entry\n");
536 rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p));
538 pr_err("SELinux: avtab: truncated entry\n");
541 for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++)
542 xperms.perms.p[i] = le32_to_cpu(buf32[i]);
543 datum.u.xperms = &xperms;
545 rc = next_entry(buf32, fp, sizeof(u32));
547 pr_err("SELinux: avtab: truncated entry\n");
550 datum.u.data = le32_to_cpu(*buf32);
552 if ((key.specified & AVTAB_TYPE) &&
553 !policydb_type_isvalid(pol, datum.u.data)) {
554 pr_err("SELinux: avtab: invalid type\n");
557 return insertf(a, &key, &datum, p);
560 static int avtab_insertf(struct avtab *a, struct avtab_key *k,
561 struct avtab_datum *d, void *p)
563 return avtab_insert(a, k, d);
566 int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
573 rc = next_entry(buf, fp, sizeof(u32));
575 pr_err("SELinux: avtab: truncated table\n");
578 nel = le32_to_cpu(buf[0]);
580 pr_err("SELinux: avtab: table is empty\n");
585 rc = avtab_alloc(a, nel);
589 for (i = 0; i < nel; i++) {
590 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
593 pr_err("SELinux: avtab: out of memory\n");
594 else if (rc == -EEXIST)
595 pr_err("SELinux: avtab: duplicate entry\n");
610 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
613 __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)];
617 buf16[0] = cpu_to_le16(cur->key.source_type);
618 buf16[1] = cpu_to_le16(cur->key.target_type);
619 buf16[2] = cpu_to_le16(cur->key.target_class);
620 buf16[3] = cpu_to_le16(cur->key.specified);
621 rc = put_entry(buf16, sizeof(u16), 4, fp);
625 if (cur->key.specified & AVTAB_XPERMS) {
626 rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp);
629 rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp);
632 for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++)
633 buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]);
634 rc = put_entry(buf32, sizeof(u32),
635 ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp);
637 buf32[0] = cpu_to_le32(cur->datum.u.data);
638 rc = put_entry(buf32, sizeof(u32), 1, fp);
645 int avtab_write(struct policydb *p, struct avtab *a, void *fp)
649 struct avtab_node *cur;
652 buf[0] = cpu_to_le32(a->nel);
653 rc = put_entry(buf, sizeof(u32), 1, fp);
657 for (i = 0; i < a->nslot; i++) {
658 for (cur = a->htable[i]; cur;
660 rc = avtab_write_item(p, cur, fp);
669 void __init avtab_cache_init(void)
671 avtab_node_cachep = kmem_cache_create("avtab_node",
672 sizeof(struct avtab_node),
673 0, SLAB_PANIC, NULL);
674 avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms",
675 sizeof(struct avtab_extended_perms),
676 0, SLAB_PANIC, NULL);