[net-next-2.6.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;
	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;
	}
	return avtab_insert_node(h, hvalue, prev, cur, key, datum);
}

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) {
			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_HASH_BUCKETS)
		nslot = MAX_AVTAB_HASH_BUCKETS;
	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, %d rules.\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 "SELinux: %s:  %d entries and %d/%d buckets used, "
	       "longest chain length %d sum of chain length^2 %llu\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) {
			printk(KERN_ERR "SELinux: avtab: truncated entry\n");
			return rc;
		}
		items2 = le32_to_cpu(buf32[0]);
		if (items2 > ARRAY_SIZE(buf32)) {
			printk(KERN_ERR "SELinux: avtab: entry overflow\n");
			return -EINVAL;

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

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

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

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

		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(KERN_ERR "SELinux: avtab: entry only had %d items, expected %d\n", items2, items);
			return -EINVAL;
		}
		return 0;
	}

	rc = next_entry(buf16, fp, sizeof(u16)*4);
	if (rc) {
		printk(KERN_ERR "SELinux: avtab: truncated entry\n");
		return rc;
	}

	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_ERR "SELinux: avtab: invalid type or class\n");
		return -EINVAL;
	}

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

	rc = next_entry(buf32, fp, sizeof(u32));
	if (rc) {
		printk(KERN_ERR "SELinux: avtab: truncated entry\n");
		return rc;
	}
	datum.data = le32_to_cpu(*buf32);
	if ((key.specified & AVTAB_TYPE) &&
	    !policydb_type_isvalid(pol, datum.data)) {
		printk(KERN_ERR "SELinux: avtab: invalid type\n");
		return -EINVAL;
	}
	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 "SELinux: avtab: truncated table\n");
		goto bad;
	}
	nel = le32_to_cpu(buf[0]);
	if (!nel) {
		printk(KERN_ERR "SELinux: 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 "SELinux: avtab: out of memory\n");
			else if (rc == -EEXIST)
				printk(KERN_ERR "SELinux: avtab: duplicate entry\n");

			goto bad;
		}
	}

	rc = 0;
out:
	return rc;

bad:
	avtab_destroy(a);
	goto out;
}

int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
{
	__le16 buf16[4];
	__le32 buf32[1];
	int rc;

	buf16[0] = cpu_to_le16(cur->key.source_type);
	buf16[1] = cpu_to_le16(cur->key.target_type);
	buf16[2] = cpu_to_le16(cur->key.target_class);
	buf16[3] = cpu_to_le16(cur->key.specified);
	rc = put_entry(buf16, sizeof(u16), 4, fp);
	if (rc)
		return rc;
	buf32[0] = cpu_to_le32(cur->datum.data);
	rc = put_entry(buf32, sizeof(u32), 1, fp);
	if (rc)
		return rc;
	return 0;
}

int avtab_write(struct policydb *p, struct avtab *a, void *fp)
{
	unsigned int i;
	int rc = 0;
	struct avtab_node *cur;
	__le32 buf[1];

	buf[0] = cpu_to_le32(a->nel);
	rc = put_entry(buf, sizeof(u32), 1, fp);
	if (rc)
		return rc;

	for (i = 0; i < a->nslot; i++) {
		for (cur = a->htable[i]; cur; cur = cur->next) {
			rc = avtab_write_item(p, cur, fp);
			if (rc)
				return rc;
		}
	}

	return rc;
}
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	*
eb5df9a7	9	* Added conditional policy language extensions
1da177e4 LT	10	*
	11	* Copyright (C) 2003 Tresys Technology, LLC
	12	* This program is free software; you can redistribute it and/or modify
eb5df9a7	13	* it under the terms of the GNU General Public License as published by
1da177e4	14	* the Free Software Foundation, version 2.
3232c110 YN	15	*
3232c110 YN	16	* Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
eb5df9a7	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*
1da177e4 LT	35	avtab_insert_node(struct avtab *h, int hvalue,
eb5df9a7	36	struct avtab_node prev, struct avtab_node cur,
1da177e4 LT	37	struct avtab_key key, struct avtab_datum datum)
1da177e4 LT	38	{
eb5df9a7	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);
eb5df9a7	87	if (!newnode)
1da177e4 LT	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 *
eb5df9a7	98	avtab_insert_nonunique(struct avtab h, struct avtab_key key, struct avtab_datum *datum)
1da177e4 LT	99	{
1da177e4 LT	100	int hvalue;
0c0e186f	101	struct avtab_node prev, cur;
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	}
0c0e186f	125	return avtab_insert_node(h, hvalue, prev, cur, key, datum);
1da177e4 LT	126	}
1da177e4 LT	127
782ebb99	128	struct avtab_datum avtab_search(struct avtab h, struct avtab_key *key)
1da177e4 LT	129	{
	130	int hvalue;
	131	struct avtab_node *cur;
782ebb99	132	u16 specified = key->specified & ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4	133
3232c110	134	if (!h \|\| !h->htable)
1da177e4 LT	135	return NULL;
1da177e4 LT	136
3232c110	137	hvalue = avtab_hash(key, h->mask);
1da177e4 LT	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 &&
782ebb99	142	(specified & cur->key.specified))
1da177e4 LT	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	*/
	162	struct avtab_node*
782ebb99	163	avtab_search_node(struct avtab h, struct avtab_key key)
1da177e4 LT	164	{
	165	int hvalue;
	166	struct avtab_node *cur;
782ebb99	167	u16 specified = key->specified & ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4	168
3232c110	169	if (!h \|\| !h->htable)
1da177e4 LT	170	return NULL;
1da177e4 LT	171
3232c110	172	hvalue = avtab_hash(key, h->mask);
1da177e4 LT	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 &&
782ebb99	177	(specified & cur->key.specified))
1da177e4 LT	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
	193	struct avtab_node*
	194	avtab_search_node_next(struct avtab_node *node, int specified)
	195	{
	196	struct avtab_node *cur;
	197
	198	if (!node)
	199	return NULL;
	200
782ebb99	201	specified &= ~(AVTAB_ENABLED\|AVTAB_ENABLED_OLD);
1da177e4 LT	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 &&
782ebb99	206	(specified & cur->key.specified))
1da177e4 LT	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
	222	void avtab_destroy(struct avtab *h)
	223	{
	224	int i;
	225	struct avtab_node cur, temp;
	226
	227	if (!h \|\| !h->htable)
	228	return;
	229
3232c110	230	for (i = 0; i < h->nslot; i++) {
1da177e4	231	cur = h->htable[i];
dbc74c65	232	while (cur) {
1da177e4 LT	233	temp = cur;
	234	cur = cur->next;
	235	kmem_cache_free(avtab_node_cachep, temp);
	236	}
	237	h->htable[i] = NULL;
	238	}
3232c110	239	kfree(h->htable);
1da177e4	240	h->htable = NULL;
3232c110 YN	241	h->nslot = 0;
3232c110 YN	242	h->mask = 0;
1da177e4 LT	243	}
1da177e4 LT	244
1da177e4 LT	245	int avtab_init(struct avtab *h)
1da177e4 LT	246	{
3232c110 YN	247	h->htable = NULL;
	248	h->nel = 0;
	249	return 0;
	250	}
	251
	252	int 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;
1da177e4	261
3232c110 YN	262	while (work) {
	263	work = work >> 1;
	264	shift++;
	265	}
	266	if (shift > 2)
	267	shift = shift - 2;
	268	nslot = 1 << shift;
00d85c83 EP	269	if (nslot > MAX_AVTAB_HASH_BUCKETS)
00d85c83 EP	270	nslot = MAX_AVTAB_HASH_BUCKETS;
3232c110 YN	271	mask = nslot - 1;
	272
	273	h->htable = kcalloc(nslot, sizeof(*(h->htable)), GFP_KERNEL);
1da177e4 LT	274	if (!h->htable)
1da177e4 LT	275	return -ENOMEM;
3232c110 YN	276
3232c110 YN	277	avtab_alloc_out:
1da177e4	278	h->nel = 0;
3232c110 YN	279	h->nslot = nslot;
3232c110 YN	280	h->mask = mask;
454d972c JM	281	printk(KERN_DEBUG "SELinux: %d avtab hash slots, %d rules.\n",
454d972c JM	282	h->nslot, nrules);
1da177e4 LT	283	return 0;
	284	}
	285
	286	void avtab_hash_eval(struct avtab h, char tag)
	287	{
	288	int i, chain_len, slots_used, max_chain_len;
3232c110	289	unsigned long long chain2_len_sum;
1da177e4 LT	290	struct avtab_node *cur;
	291
	292	slots_used = 0;
	293	max_chain_len = 0;
3232c110 YN	294	chain2_len_sum = 0;
3232c110 YN	295	for (i = 0; i < h->nslot; i++) {
1da177e4 LT	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;
3232c110	307	chain2_len_sum += chain_len * chain_len;
1da177e4 LT	308	}
	309	}
	310
744ba35e	311	printk(KERN_DEBUG "SELinux: %s: %d entries and %d/%d buckets used, "
f5269710	312	"longest chain length %d sum of chain length^2 %llu\n",
3232c110 YN	313	tag, h->nel, slots_used, h->nslot, max_chain_len,
3232c110 YN	314	chain2_len_sum);
1da177e4 LT	315	}
1da177e4 LT	316
782ebb99 SS	317	static uint16_t spec_order[] = {
	318	AVTAB_ALLOWED,
	319	AVTAB_AUDITDENY,
	320	AVTAB_AUDITALLOW,
	321	AVTAB_TRANSITION,
	322	AVTAB_CHANGE,
	323	AVTAB_MEMBER
	324	};
	325
45e5421e	326	int avtab_read_item(struct avtab a, void fp, struct policydb *pol,
eb5df9a7	327	int (insertf)(struct avtab a, struct avtab_key *k,
782ebb99 SS	328	struct avtab_datum d, void p),
782ebb99 SS	329	void *p)
1da177e4	330	{
b5bf6c55 AD	331	__le16 buf16[4];
	332	u16 enabled;
	333	__le32 buf32[7];
45e5421e	334	u32 items, items2, val, vers = pol->policyvers;
782ebb99 SS	335	struct avtab_key key;
	336	struct avtab_datum datum;
	337	int i, rc;
45e5421e	338	unsigned set;
782ebb99 SS	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));
9e0bd4cb	345	if (rc) {
454d972c	346	printk(KERN_ERR "SELinux: avtab: truncated entry\n");
9e0bd4cb	347	return rc;
782ebb99 SS	348	}
	349	items2 = le32_to_cpu(buf32[0]);
	350	if (items2 > ARRAY_SIZE(buf32)) {
454d972c	351	printk(KERN_ERR "SELinux: avtab: entry overflow\n");
9e0bd4cb	352	return -EINVAL;
1da177e4	353
782ebb99 SS	354	}
782ebb99 SS	355	rc = next_entry(buf32, fp, sizeof(u32)*items2);
9e0bd4cb	356	if (rc) {
454d972c	357	printk(KERN_ERR "SELinux: avtab: truncated entry\n");
9e0bd4cb	358	return rc;
782ebb99 SS	359	}
782ebb99 SS	360	items = 0;
1da177e4	361
782ebb99 SS	362	val = le32_to_cpu(buf32[items++]);
	363	key.source_type = (u16)val;
	364	if (key.source_type != val) {
744ba35e	365	printk(KERN_ERR "SELinux: avtab: truncated source type\n");
9e0bd4cb	366	return -EINVAL;
782ebb99 SS	367	}
	368	val = le32_to_cpu(buf32[items++]);
	369	key.target_type = (u16)val;
	370	if (key.target_type != val) {
744ba35e	371	printk(KERN_ERR "SELinux: avtab: truncated target type\n");
9e0bd4cb	372	return -EINVAL;
782ebb99 SS	373	}
	374	val = le32_to_cpu(buf32[items++]);
	375	key.target_class = (u16)val;
	376	if (key.target_class != val) {
744ba35e	377	printk(KERN_ERR "SELinux: avtab: truncated target class\n");
9e0bd4cb	378	return -EINVAL;
782ebb99 SS	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))) {
744ba35e	385	printk(KERN_ERR "SELinux: avtab: null entry\n");
9e0bd4cb	386	return -EINVAL;
782ebb99 SS	387	}
	388	if ((val & AVTAB_AV) &&
	389	(val & AVTAB_TYPE)) {
744ba35e	390	printk(KERN_ERR "SELinux: avtab: entry has both access vectors and types\n");
9e0bd4cb	391	return -EINVAL;
782ebb99 SS	392	}
782ebb99 SS	393
32725ad8	394	for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
782ebb99 SS	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);
eb5df9a7 EP	399	if (rc)
eb5df9a7 EP	400	return rc;
782ebb99 SS	401	}
	402	}
	403
	404	if (items != items2) {
744ba35e	405	printk(KERN_ERR "SELinux: avtab: entry only had %d items, expected %d\n", items2, items);
9e0bd4cb	406	return -EINVAL;
782ebb99 SS	407	}
782ebb99 SS	408	return 0;
1da177e4	409	}
782ebb99 SS	410
782ebb99 SS	411	rc = next_entry(buf16, fp, sizeof(u16)*4);
9e0bd4cb	412	if (rc) {
744ba35e	413	printk(KERN_ERR "SELinux: avtab: truncated entry\n");
9e0bd4cb	414	return rc;
1da177e4	415	}
782ebb99	416
1da177e4	417	items = 0;
782ebb99 SS	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
45e5421e SS	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)) {
744ba35e	426	printk(KERN_ERR "SELinux: avtab: invalid type or class\n");
9e0bd4cb	427	return -EINVAL;
45e5421e SS	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) {
744ba35e	436	printk(KERN_ERR "SELinux: avtab: more than one specifier\n");
9e0bd4cb	437	return -EINVAL;
45e5421e SS	438	}
45e5421e SS	439
782ebb99	440	rc = next_entry(buf32, fp, sizeof(u32));
9e0bd4cb	441	if (rc) {
744ba35e	442	printk(KERN_ERR "SELinux: avtab: truncated entry\n");
9e0bd4cb	443	return rc;
1da177e4	444	}
782ebb99	445	datum.data = le32_to_cpu(*buf32);
45e5421e SS	446	if ((key.specified & AVTAB_TYPE) &&
45e5421e SS	447	!policydb_type_isvalid(pol, datum.data)) {
744ba35e	448	printk(KERN_ERR "SELinux: avtab: invalid type\n");
9e0bd4cb	449	return -EINVAL;
45e5421e	450	}
782ebb99 SS	451	return insertf(a, &key, &datum, p);
782ebb99 SS	452	}
1da177e4	453
782ebb99 SS	454	static 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);
1da177e4 LT	458	}
1da177e4 LT	459
45e5421e	460	int avtab_read(struct avtab a, void fp, struct policydb *pol)
1da177e4 LT	461	{
1da177e4 LT	462	int rc;
b5bf6c55	463	__le32 buf[1];
1da177e4 LT	464	u32 nel, i;
	465
	466
	467	rc = next_entry(buf, fp, sizeof(u32));
	468	if (rc < 0) {
454d972c	469	printk(KERN_ERR "SELinux: avtab: truncated table\n");
1da177e4 LT	470	goto bad;
	471	}
	472	nel = le32_to_cpu(buf[0]);
	473	if (!nel) {
454d972c	474	printk(KERN_ERR "SELinux: avtab: table is empty\n");
1da177e4 LT	475	rc = -EINVAL;
	476	goto bad;
	477	}
3232c110 YN	478
	479	rc = avtab_alloc(a, nel);
	480	if (rc)
	481	goto bad;
	482
1da177e4	483	for (i = 0; i < nel; i++) {
45e5421e	484	rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
1da177e4 LT	485	if (rc) {
1da177e4 LT	486	if (rc == -ENOMEM)
454d972c	487	printk(KERN_ERR "SELinux: avtab: out of memory\n");
782ebb99	488	else if (rc == -EEXIST)
454d972c	489	printk(KERN_ERR "SELinux: avtab: duplicate entry\n");
9e0bd4cb	490
1da177e4 LT	491	goto bad;
	492	}
	493	}
	494
	495	rc = 0;
	496	out:
	497	return rc;
	498
	499	bad:
	500	avtab_destroy(a);
	501	goto out;
	502	}
	503
cee74f47 EP	504	int 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
	524	int 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	}
1da177e4 LT	546	void avtab_cache_init(void)
	547	{
	548	avtab_node_cachep = kmem_cache_create("avtab_node",
	549	sizeof(struct avtab_node),
20c2df83	550	0, SLAB_PANIC, NULL);
1da177e4 LT	551	}
	552
	553	void avtab_cache_destroy(void)
	554	{
eb5df9a7	555	kmem_cache_destroy(avtab_node_cachep);
1da177e4	556	}