[deliverable/linux.git] / security / selinux / ss / avtab.c

/*
 * Implementation of the access vector table type.
 *
 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
 */

/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 *
 * 	Added conditional policy language extensions
 *
 * Copyright (C) 2003 Tresys Technology, LLC
 *	This program is free software; you can redistribute it and/or modify
 *  	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation, version 2.
 *
 * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
 * 	Tuned number of hash slots for avtab to reduce memory usage
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include "avtab.h"
#include "policydb.h"

static struct kmem_cache *avtab_node_cachep;

static inline int avtab_hash(struct avtab_key *keyp, u16 mask)
{
	return ((keyp->target_class + (keyp->target_type << 2) +
		 (keyp->source_type << 9)) & mask);
}

static struct avtab_node*
avtab_insert_node(struct avtab *h, int hvalue,
		  struct avtab_node * prev, struct avtab_node * cur,
		  struct avtab_key *key, struct avtab_datum *datum)
{
	struct avtab_node * newnode;
	newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
	if (newnode == NULL)
		return NULL;
	newnode->key = *key;
	newnode->datum = *datum;
	if (prev) {
		newnode->next = prev->next;
		prev->next = newnode;
	} else {
		newnode->next = h->htable[hvalue];
		h->htable[hvalue] = newnode;
	}

	h->nel++;
	return newnode;
}

static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
{
	int hvalue;
	struct avtab_node *prev, *cur, *newnode;
	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

	if (!h || !h->htable)
		return -EINVAL;

	hvalue = avtab_hash(key, h->mask);
	for (prev = NULL, cur = h->htable[hvalue];
	     cur;
	     prev = cur, cur = cur->next) {
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class == cur->key.target_class &&
		    (specified & cur->key.specified))
			return -EEXIST;
		if (key->source_type < cur->key.source_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type < cur->key.target_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class < cur->key.target_class)
			break;
	}

	newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);
	if(!newnode)
		return -ENOMEM;

	return 0;
}

/* Unlike avtab_insert(), this function allow multiple insertions of the same
 * key/specified mask into the table, as needed by the conditional avtab.
 * It also returns a pointer to the node inserted.
 */
struct avtab_node *
avtab_insert_nonunique(struct avtab * h, struct avtab_key * key, struct avtab_datum * datum)
{
	int hvalue;
	struct avtab_node *prev, *cur, *newnode;
	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

	if (!h || !h->htable)
		return NULL;
	hvalue = avtab_hash(key, h->mask);
	for (prev = NULL, cur = h->htable[hvalue];
	     cur;
	     prev = cur, cur = cur->next) {
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class == cur->key.target_class &&
		    (specified & cur->key.specified))
			break;
		if (key->source_type < cur->key.source_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type < cur->key.target_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class < cur->key.target_class)
			break;
	}
	newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);

	return newnode;
}

struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
{
	int hvalue;
	struct avtab_node *cur;
	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

	if (!h || !h->htable)
		return NULL;

	hvalue = avtab_hash(key, h->mask);
	for (cur = h->htable[hvalue]; cur; cur = cur->next) {
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class == cur->key.target_class &&
		    (specified & cur->key.specified))
			return &cur->datum;

		if (key->source_type < cur->key.source_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type < cur->key.target_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class < cur->key.target_class)
			break;
	}

	return NULL;
}

/* This search function returns a node pointer, and can be used in
 * conjunction with avtab_search_next_node()
 */
struct avtab_node*
avtab_search_node(struct avtab *h, struct avtab_key *key)
{
	int hvalue;
	struct avtab_node *cur;
	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

	if (!h || !h->htable)
		return NULL;

	hvalue = avtab_hash(key, h->mask);
	for (cur = h->htable[hvalue]; cur; cur = cur->next) {
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class == cur->key.target_class &&
		    (specified & cur->key.specified))
			return cur;

		if (key->source_type < cur->key.source_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type < cur->key.target_type)
			break;
		if (key->source_type == cur->key.source_type &&
		    key->target_type == cur->key.target_type &&
		    key->target_class < cur->key.target_class)
			break;
	}
	return NULL;
}

struct avtab_node*
avtab_search_node_next(struct avtab_node *node, int specified)
{
	struct avtab_node *cur;

	if (!node)
		return NULL;

	specified &= ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
	for (cur = node->next; cur; cur = cur->next) {
		if (node->key.source_type == cur->key.source_type &&
		    node->key.target_type == cur->key.target_type &&
		    node->key.target_class == cur->key.target_class &&
		    (specified & cur->key.specified))
			return cur;

		if (node->key.source_type < cur->key.source_type)
			break;
		if (node->key.source_type == cur->key.source_type &&
		    node->key.target_type < cur->key.target_type)
			break;
		if (node->key.source_type == cur->key.source_type &&
		    node->key.target_type == cur->key.target_type &&
		    node->key.target_class < cur->key.target_class)
			break;
	}
	return NULL;
}

void avtab_destroy(struct avtab *h)
{
	int i;
	struct avtab_node *cur, *temp;

	if (!h || !h->htable)
		return;

	for (i = 0; i < h->nslot; i++) {
		cur = h->htable[i];
		while (cur != NULL) {
			temp = cur;
			cur = cur->next;
			kmem_cache_free(avtab_node_cachep, temp);
		}
		h->htable[i] = NULL;
	}
	kfree(h->htable);
	h->htable = NULL;
	h->nslot = 0;
	h->mask = 0;
}

int avtab_init(struct avtab *h)
{
	h->htable = NULL;
	h->nel = 0;
	return 0;
}

int avtab_alloc(struct avtab *h, u32 nrules)
{
	u16 mask = 0;
	u32 shift = 0;
	u32 work = nrules;
	u32 nslot = 0;

	if (nrules == 0)
		goto avtab_alloc_out;

	while (work) {
		work  = work >> 1;
		shift++;
	}
	if (shift > 2)
		shift = shift - 2;
	nslot = 1 << shift;
	if (nslot > MAX_AVTAB_SIZE)
		nslot = MAX_AVTAB_SIZE;
	mask = nslot - 1;

	h->htable = kcalloc(nslot, sizeof(*(h->htable)), GFP_KERNEL);
	if (!h->htable)
		return -ENOMEM;

 avtab_alloc_out:
	h->nel = 0;
	h->nslot = nslot;
	h->mask = mask;
	printk(KERN_DEBUG "SELinux:%d avtab hash slots allocated. "
	       "Num of rules:%d\n", h->nslot, nrules);
	return 0;
}

void avtab_hash_eval(struct avtab *h, char *tag)
{
	int i, chain_len, slots_used, max_chain_len;
	unsigned long long chain2_len_sum;
	struct avtab_node *cur;

	slots_used = 0;
	max_chain_len = 0;
	chain2_len_sum = 0;
	for (i = 0; i < h->nslot; i++) {
		cur = h->htable[i];
		if (cur) {
			slots_used++;
			chain_len = 0;
			while (cur) {
				chain_len++;
				cur = cur->next;
			}

			if (chain_len > max_chain_len)
				max_chain_len = chain_len;
			chain2_len_sum += chain_len * chain_len;
		}
	}

	printk(KERN_DEBUG "%s:  %d entries and %d/%d buckets used, longest "
	       "chain length %d sum of chain length^2 %Lu\n",
	       tag, h->nel, slots_used, h->nslot, max_chain_len,
	       chain2_len_sum);
}

static uint16_t spec_order[] = {
	AVTAB_ALLOWED,
	AVTAB_AUDITDENY,
	AVTAB_AUDITALLOW,
	AVTAB_TRANSITION,
	AVTAB_CHANGE,
	AVTAB_MEMBER
};

int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
	            int (*insertf)(struct avtab *a, struct avtab_key *k,
				   struct avtab_datum *d, void *p),
		    void *p)
{
	__le16 buf16[4];
	u16 enabled;
	__le32 buf32[7];
	u32 items, items2, val, vers = pol->policyvers;
	struct avtab_key key;
	struct avtab_datum datum;
	int i, rc;
	unsigned set;

	memset(&key, 0, sizeof(struct avtab_key));
	memset(&datum, 0, sizeof(struct avtab_datum));

	if (vers < POLICYDB_VERSION_AVTAB) {
		rc = next_entry(buf32, fp, sizeof(u32));
		if (rc < 0) {
			printk(KERN_ERR "security: avtab: truncated entry\n");
			return -1;
		}
		items2 = le32_to_cpu(buf32[0]);
		if (items2 > ARRAY_SIZE(buf32)) {
			printk(KERN_ERR "security: avtab: entry overflow\n");
			return -1;

		}
		rc = next_entry(buf32, fp, sizeof(u32)*items2);
		if (rc < 0) {
			printk(KERN_ERR "security: avtab: truncated entry\n");
			return -1;
		}
		items = 0;

		val = le32_to_cpu(buf32[items++]);
		key.source_type = (u16)val;
		if (key.source_type != val) {
			printk("security: avtab: truncated source type\n");
			return -1;
		}
		val = le32_to_cpu(buf32[items++]);
		key.target_type = (u16)val;
		if (key.target_type != val) {
			printk("security: avtab: truncated target type\n");
			return -1;
		}
		val = le32_to_cpu(buf32[items++]);
		key.target_class = (u16)val;
		if (key.target_class != val) {
			printk("security: avtab: truncated target class\n");
			return -1;
		}

		val = le32_to_cpu(buf32[items++]);
		enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;

		if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
			printk("security: avtab: null entry\n");
			return -1;
		}
		if ((val & AVTAB_AV) &&
		    (val & AVTAB_TYPE)) {
			printk("security: avtab: entry has both access vectors and types\n");
			return -1;
		}

		for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
			if (val & spec_order[i]) {
				key.specified = spec_order[i] | enabled;
				datum.data = le32_to_cpu(buf32[items++]);
				rc = insertf(a, &key, &datum, p);
				if (rc) return rc;
			}
		}

		if (items != items2) {
			printk("security: avtab: entry only had %d items, expected %d\n", items2, items);
			return -1;
		}
		return 0;
	}

	rc = next_entry(buf16, fp, sizeof(u16)*4);
	if (rc < 0) {
		printk("security: avtab: truncated entry\n");
		return -1;
	}

	items = 0;
	key.source_type = le16_to_cpu(buf16[items++]);
	key.target_type = le16_to_cpu(buf16[items++]);
	key.target_class = le16_to_cpu(buf16[items++]);
	key.specified = le16_to_cpu(buf16[items++]);

	if (!policydb_type_isvalid(pol, key.source_type) ||
	    !policydb_type_isvalid(pol, key.target_type) ||
	    !policydb_class_isvalid(pol, key.target_class)) {
		printk(KERN_WARNING "security: avtab: invalid type or class\n");
		return -1;
	}

	set = 0;
	for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
		if (key.specified & spec_order[i])
			set++;
	}
	if (!set || set > 1) {
		printk(KERN_WARNING
			"security:  avtab:  more than one specifier\n");
		return -1;
	}

	rc = next_entry(buf32, fp, sizeof(u32));
	if (rc < 0) {
		printk("security: avtab: truncated entry\n");
		return -1;
	}
	datum.data = le32_to_cpu(*buf32);
	if ((key.specified & AVTAB_TYPE) &&
	    !policydb_type_isvalid(pol, datum.data)) {
		printk(KERN_WARNING "security: avtab: invalid type\n");
		return -1;
	}
	return insertf(a, &key, &datum, p);
}

static int avtab_insertf(struct avtab *a, struct avtab_key *k,
			 struct avtab_datum *d, void *p)
{
	return avtab_insert(a, k, d);
}

int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
{
	int rc;
	__le32 buf[1];
	u32 nel, i;


	rc = next_entry(buf, fp, sizeof(u32));
	if (rc < 0) {
		printk(KERN_ERR "security: avtab: truncated table\n");
		goto bad;
	}
	nel = le32_to_cpu(buf[0]);
	if (!nel) {
		printk(KERN_ERR "security: avtab: table is empty\n");
		rc = -EINVAL;
		goto bad;
	}

	rc = avtab_alloc(a, nel);
	if (rc)
		goto bad;

	for (i = 0; i < nel; i++) {
		rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
		if (rc) {
			if (rc == -ENOMEM)
				printk(KERN_ERR "security: avtab: out of memory\n");
			else if (rc == -EEXIST)
				printk(KERN_ERR "security: avtab: duplicate entry\n");
			else
				rc = -EINVAL;
			goto bad;
		}
	}

	rc = 0;
out:
	return rc;

bad:
	avtab_destroy(a);
	goto out;
}

void avtab_cache_init(void)
{
	avtab_node_cachep = kmem_cache_create("avtab_node",
					      sizeof(struct avtab_node),
					      0, SLAB_PANIC, NULL);
}

void avtab_cache_destroy(void)
{
	kmem_cache_destroy (avtab_node_cachep);
}
Commit	Line	Data
1da177e4 LT	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.
3232c110 YN	15	*
	16	* Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
	17	* Tuned number of hash slots for avtab to reduce memory usage
1da177e4 LT	18	*/
	19
	20	#include <linux/kernel.h>
	21	#include <linux/slab.h>
1da177e4	22	#include <linux/errno.h>
1da177e4 LT	23	#include "avtab.h"
	24	#include "policydb.h"
	25
e18b890b	26	static struct kmem_cache *avtab_node_cachep;
1da177e4	27
3232c110 YN	28	static 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
1da177e4 LT	34	static struct avtab_node*
	35	avtab_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;
c3762229	40	newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
1da177e4 LT	41	if (newnode == NULL)
1da177e4 LT	42	return NULL;
1da177e4 LT	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
	57	static 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;
782ebb99	61	u16 specified = key->specified & ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4	62
3232c110	63	if (!h \|\| !h->htable)
1da177e4 LT	64	return -EINVAL;
1da177e4 LT	65
3232c110	66	hvalue = avtab_hash(key, h->mask);
1da177e4 LT	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 &&
782ebb99	73	(specified & cur->key.specified))
1da177e4 LT	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	*/
	97	struct avtab_node *
	98	avtab_insert_nonunique(struct avtab * h, struct avtab_key * key, struct avtab_datum * datum)
	99	{
	100	int hvalue;
	101	struct avtab_node prev, cur, *newnode;
782ebb99	102	u16 specified = key->specified & ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4	103
3232c110	104	if (!h \|\| !h->htable)
1da177e4	105	return NULL;
3232c110	106	hvalue = avtab_hash(key, h->mask);
1da177e4 LT	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 &&
782ebb99	113	(specified & cur->key.specified))
1da177e4 LT	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	newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);
	126
	127	return newnode;
	128	}
	129
782ebb99	130	struct avtab_datum avtab_search(struct avtab h, struct avtab_key *key)
1da177e4 LT	131	{
	132	int hvalue;
	133	struct avtab_node *cur;
782ebb99	134	u16 specified = key->specified & ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4	135
3232c110	136	if (!h \|\| !h->htable)
1da177e4 LT	137	return NULL;
1da177e4 LT	138
3232c110	139	hvalue = avtab_hash(key, h->mask);
1da177e4 LT	140	for (cur = h->htable[hvalue]; cur; cur = cur->next) {
	141	if (key->source_type == cur->key.source_type &&
	142	key->target_type == cur->key.target_type &&
	143	key->target_class == cur->key.target_class &&
782ebb99	144	(specified & cur->key.specified))
1da177e4 LT	145	return &cur->datum;
	146
	147	if (key->source_type < cur->key.source_type)
	148	break;
	149	if (key->source_type == cur->key.source_type &&
	150	key->target_type < cur->key.target_type)
	151	break;
	152	if (key->source_type == cur->key.source_type &&
	153	key->target_type == cur->key.target_type &&
	154	key->target_class < cur->key.target_class)
	155	break;
	156	}
	157
	158	return NULL;
	159	}
	160
	161	/* This search function returns a node pointer, and can be used in
	162	* conjunction with avtab_search_next_node()
	163	*/
	164	struct avtab_node*
782ebb99	165	avtab_search_node(struct avtab h, struct avtab_key key)
1da177e4 LT	166	{
	167	int hvalue;
	168	struct avtab_node *cur;
782ebb99	169	u16 specified = key->specified & ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4	170
3232c110	171	if (!h \|\| !h->htable)
1da177e4 LT	172	return NULL;
1da177e4 LT	173
3232c110	174	hvalue = avtab_hash(key, h->mask);
1da177e4 LT	175	for (cur = h->htable[hvalue]; cur; cur = cur->next) {
	176	if (key->source_type == cur->key.source_type &&
	177	key->target_type == cur->key.target_type &&
	178	key->target_class == cur->key.target_class &&
782ebb99	179	(specified & cur->key.specified))
1da177e4 LT	180	return cur;
	181
	182	if (key->source_type < cur->key.source_type)
	183	break;
	184	if (key->source_type == cur->key.source_type &&
	185	key->target_type < cur->key.target_type)
	186	break;
	187	if (key->source_type == cur->key.source_type &&
	188	key->target_type == cur->key.target_type &&
	189	key->target_class < cur->key.target_class)
	190	break;
	191	}
	192	return NULL;
	193	}
	194
	195	struct avtab_node*
	196	avtab_search_node_next(struct avtab_node *node, int specified)
	197	{
	198	struct avtab_node *cur;
	199
	200	if (!node)
	201	return NULL;
	202
782ebb99	203	specified &= ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4 LT	204	for (cur = node->next; cur; cur = cur->next) {
	205	if (node->key.source_type == cur->key.source_type &&
	206	node->key.target_type == cur->key.target_type &&
	207	node->key.target_class == cur->key.target_class &&
782ebb99	208	(specified & cur->key.specified))
1da177e4 LT	209	return cur;
	210
	211	if (node->key.source_type < cur->key.source_type)
	212	break;
	213	if (node->key.source_type == cur->key.source_type &&
	214	node->key.target_type < cur->key.target_type)
	215	break;
	216	if (node->key.source_type == cur->key.source_type &&
	217	node->key.target_type == cur->key.target_type &&
	218	node->key.target_class < cur->key.target_class)
	219	break;
	220	}
	221	return NULL;
	222	}
	223
	224	void avtab_destroy(struct avtab *h)
	225	{
	226	int i;
	227	struct avtab_node cur, temp;
	228
	229	if (!h \|\| !h->htable)
	230	return;
	231
3232c110	232	for (i = 0; i < h->nslot; i++) {
1da177e4 LT	233	cur = h->htable[i];
	234	while (cur != NULL) {
	235	temp = cur;
	236	cur = cur->next;
	237	kmem_cache_free(avtab_node_cachep, temp);
	238	}
	239	h->htable[i] = NULL;
	240	}
3232c110	241	kfree(h->htable);
1da177e4	242	h->htable = NULL;
3232c110 YN	243	h->nslot = 0;
3232c110 YN	244	h->mask = 0;
1da177e4 LT	245	}
1da177e4 LT	246
1da177e4 LT	247	int avtab_init(struct avtab *h)
1da177e4 LT	248	{
3232c110 YN	249	h->htable = NULL;
	250	h->nel = 0;
	251	return 0;
	252	}
	253
	254	int avtab_alloc(struct avtab *h, u32 nrules)
	255	{
	256	u16 mask = 0;
	257	u32 shift = 0;
	258	u32 work = nrules;
	259	u32 nslot = 0;
	260
	261	if (nrules == 0)
	262	goto avtab_alloc_out;
1da177e4	263
3232c110 YN	264	while (work) {
	265	work = work >> 1;
	266	shift++;
	267	}
	268	if (shift > 2)
	269	shift = shift - 2;
	270	nslot = 1 << shift;
	271	if (nslot > MAX_AVTAB_SIZE)
	272	nslot = MAX_AVTAB_SIZE;
	273	mask = nslot - 1;
	274
	275	h->htable = kcalloc(nslot, sizeof(*(h->htable)), GFP_KERNEL);
1da177e4 LT	276	if (!h->htable)
1da177e4 LT	277	return -ENOMEM;
3232c110 YN	278
3232c110 YN	279	avtab_alloc_out:
1da177e4	280	h->nel = 0;
3232c110 YN	281	h->nslot = nslot;
3232c110 YN	282	h->mask = mask;
19c5fc19	283	printk(KERN_DEBUG "SELinux:%d avtab hash slots allocated. "
3232c110	284	"Num of rules:%d\n", h->nslot, nrules);
1da177e4 LT	285	return 0;
	286	}
	287
	288	void avtab_hash_eval(struct avtab h, char tag)
	289	{
	290	int i, chain_len, slots_used, max_chain_len;
3232c110	291	unsigned long long chain2_len_sum;
1da177e4 LT	292	struct avtab_node *cur;
	293
	294	slots_used = 0;
	295	max_chain_len = 0;
3232c110 YN	296	chain2_len_sum = 0;
3232c110 YN	297	for (i = 0; i < h->nslot; i++) {
1da177e4 LT	298	cur = h->htable[i];
	299	if (cur) {
	300	slots_used++;
	301	chain_len = 0;
	302	while (cur) {
	303	chain_len++;
	304	cur = cur->next;
	305	}
	306
	307	if (chain_len > max_chain_len)
	308	max_chain_len = chain_len;
3232c110	309	chain2_len_sum += chain_len * chain_len;
1da177e4 LT	310	}
	311	}
	312
fadcdb45	313	printk(KERN_DEBUG "%s: %d entries and %d/%d buckets used, longest "
3232c110 YN	314	"chain length %d sum of chain length^2 %Lu\n",
	315	tag, h->nel, slots_used, h->nslot, max_chain_len,
	316	chain2_len_sum);
1da177e4 LT	317	}
1da177e4 LT	318
782ebb99 SS	319	static uint16_t spec_order[] = {
	320	AVTAB_ALLOWED,
	321	AVTAB_AUDITDENY,
	322	AVTAB_AUDITALLOW,
	323	AVTAB_TRANSITION,
	324	AVTAB_CHANGE,
	325	AVTAB_MEMBER
	326	};
	327
45e5421e	328	int avtab_read_item(struct avtab a, void fp, struct policydb *pol,
782ebb99 SS	329	int (insertf)(struct avtab a, struct avtab_key *k,
	330	struct avtab_datum d, void p),
	331	void *p)
1da177e4	332	{
b5bf6c55 AD	333	__le16 buf16[4];
	334	u16 enabled;
	335	__le32 buf32[7];
45e5421e	336	u32 items, items2, val, vers = pol->policyvers;
782ebb99 SS	337	struct avtab_key key;
	338	struct avtab_datum datum;
	339	int i, rc;
45e5421e	340	unsigned set;
782ebb99 SS	341
	342	memset(&key, 0, sizeof(struct avtab_key));
	343	memset(&datum, 0, sizeof(struct avtab_datum));
	344
	345	if (vers < POLICYDB_VERSION_AVTAB) {
	346	rc = next_entry(buf32, fp, sizeof(u32));
	347	if (rc < 0) {
	348	printk(KERN_ERR "security: avtab: truncated entry\n");
	349	return -1;
	350	}
	351	items2 = le32_to_cpu(buf32[0]);
	352	if (items2 > ARRAY_SIZE(buf32)) {
	353	printk(KERN_ERR "security: avtab: entry overflow\n");
	354	return -1;
1da177e4	355
782ebb99 SS	356	}
	357	rc = next_entry(buf32, fp, sizeof(u32)*items2);
	358	if (rc < 0) {
	359	printk(KERN_ERR "security: avtab: truncated entry\n");
	360	return -1;
	361	}
	362	items = 0;
1da177e4	363
782ebb99 SS	364	val = le32_to_cpu(buf32[items++]);
	365	key.source_type = (u16)val;
	366	if (key.source_type != val) {
	367	printk("security: avtab: truncated source type\n");
	368	return -1;
	369	}
	370	val = le32_to_cpu(buf32[items++]);
	371	key.target_type = (u16)val;
	372	if (key.target_type != val) {
	373	printk("security: avtab: truncated target type\n");
	374	return -1;
	375	}
	376	val = le32_to_cpu(buf32[items++]);
	377	key.target_class = (u16)val;
	378	if (key.target_class != val) {
	379	printk("security: avtab: truncated target class\n");
	380	return -1;
	381	}
	382
	383	val = le32_to_cpu(buf32[items++]);
	384	enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
	385
	386	if (!(val & (AVTAB_AV \| AVTAB_TYPE))) {
	387	printk("security: avtab: null entry\n");
	388	return -1;
	389	}
	390	if ((val & AVTAB_AV) &&
	391	(val & AVTAB_TYPE)) {
	392	printk("security: avtab: entry has both access vectors and types\n");
	393	return -1;
	394	}
	395
32725ad8	396	for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
782ebb99 SS	397	if (val & spec_order[i]) {
	398	key.specified = spec_order[i] \| enabled;
	399	datum.data = le32_to_cpu(buf32[items++]);
	400	rc = insertf(a, &key, &datum, p);
	401	if (rc) return rc;
	402	}
	403	}
	404
	405	if (items != items2) {
	406	printk("security: avtab: entry only had %d items, expected %d\n", items2, items);
	407	return -1;
	408	}
	409	return 0;
1da177e4	410	}
782ebb99 SS	411
782ebb99 SS	412	rc = next_entry(buf16, fp, sizeof(u16)*4);
1da177e4	413	if (rc < 0) {
782ebb99 SS	414	printk("security: avtab: truncated entry\n");
782ebb99 SS	415	return -1;
1da177e4	416	}
782ebb99	417
1da177e4	418	items = 0;
782ebb99 SS	419	key.source_type = le16_to_cpu(buf16[items++]);
	420	key.target_type = le16_to_cpu(buf16[items++]);
	421	key.target_class = le16_to_cpu(buf16[items++]);
	422	key.specified = le16_to_cpu(buf16[items++]);
	423
45e5421e SS	424	if (!policydb_type_isvalid(pol, key.source_type) \|\|
	425	!policydb_type_isvalid(pol, key.target_type) \|\|
	426	!policydb_class_isvalid(pol, key.target_class)) {
	427	printk(KERN_WARNING "security: avtab: invalid type or class\n");
	428	return -1;
	429	}
	430
	431	set = 0;
	432	for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
	433	if (key.specified & spec_order[i])
	434	set++;
	435	}
	436	if (!set \|\| set > 1) {
	437	printk(KERN_WARNING
	438	"security: avtab: more than one specifier\n");
	439	return -1;
	440	}
	441
782ebb99 SS	442	rc = next_entry(buf32, fp, sizeof(u32));
	443	if (rc < 0) {
	444	printk("security: avtab: truncated entry\n");
	445	return -1;
1da177e4	446	}
782ebb99	447	datum.data = le32_to_cpu(*buf32);
45e5421e SS	448	if ((key.specified & AVTAB_TYPE) &&
	449	!policydb_type_isvalid(pol, datum.data)) {
	450	printk(KERN_WARNING "security: avtab: invalid type\n");
	451	return -1;
	452	}
782ebb99 SS	453	return insertf(a, &key, &datum, p);
782ebb99 SS	454	}
1da177e4	455
782ebb99 SS	456	static int avtab_insertf(struct avtab a, struct avtab_key k,
	457	struct avtab_datum d, void p)
	458	{
	459	return avtab_insert(a, k, d);
1da177e4 LT	460	}
1da177e4 LT	461
45e5421e	462	int avtab_read(struct avtab a, void fp, struct policydb *pol)
1da177e4 LT	463	{
1da177e4 LT	464	int rc;
b5bf6c55	465	__le32 buf[1];
1da177e4 LT	466	u32 nel, i;
	467
	468
	469	rc = next_entry(buf, fp, sizeof(u32));
	470	if (rc < 0) {
	471	printk(KERN_ERR "security: avtab: truncated table\n");
	472	goto bad;
	473	}
	474	nel = le32_to_cpu(buf[0]);
	475	if (!nel) {
	476	printk(KERN_ERR "security: avtab: table is empty\n");
	477	rc = -EINVAL;
	478	goto bad;
	479	}
3232c110 YN	480
	481	rc = avtab_alloc(a, nel);
	482	if (rc)
	483	goto bad;
	484
1da177e4	485	for (i = 0; i < nel; i++) {
45e5421e	486	rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
1da177e4 LT	487	if (rc) {
	488	if (rc == -ENOMEM)
	489	printk(KERN_ERR "security: avtab: out of memory\n");
782ebb99	490	else if (rc == -EEXIST)
1da177e4	491	printk(KERN_ERR "security: avtab: duplicate entry\n");
782ebb99 SS	492	else
782ebb99 SS	493	rc = -EINVAL;
1da177e4 LT	494	goto bad;
	495	}
	496	}
	497
	498	rc = 0;
	499	out:
	500	return rc;
	501
	502	bad:
	503	avtab_destroy(a);
	504	goto out;
	505	}
	506
	507	void avtab_cache_init(void)
	508	{
	509	avtab_node_cachep = kmem_cache_create("avtab_node",
	510	sizeof(struct avtab_node),
20c2df83	511	0, SLAB_PANIC, NULL);
1da177e4 LT	512	}
	513
	514	void avtab_cache_destroy(void)
	515	{
	516	kmem_cache_destroy (avtab_node_cachep);
	517	}