[linux-2.6-block.git] / security / integrity / iint.c

/*
 * Copyright (C) 2008 IBM Corporation
 *
 * Authors:
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * 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 of the
 * License.
 *
 * File: integrity_iint.c
 *	- implements the integrity hooks: integrity_inode_alloc,
 *	  integrity_inode_free
 *	- cache integrity information associated with an inode
 *	  using a rbtree tree.
 */
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/rbtree.h>
#include "integrity.h"

static struct rb_root integrity_iint_tree = RB_ROOT;
static DEFINE_RWLOCK(integrity_iint_lock);
static struct kmem_cache *iint_cache __read_mostly;

int iint_initialized;

/*
 * __integrity_iint_find - return the iint associated with an inode
 */
static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
{
	struct integrity_iint_cache *iint;
	struct rb_node *n = integrity_iint_tree.rb_node;

	while (n) {
		iint = rb_entry(n, struct integrity_iint_cache, rb_node);

		if (inode < iint->inode)
			n = n->rb_left;
		else if (inode > iint->inode)
			n = n->rb_right;
		else
			break;
	}
	if (!n)
		return NULL;

	return iint;
}

/*
 * integrity_iint_find - return the iint associated with an inode
 */
struct integrity_iint_cache *integrity_iint_find(struct inode *inode)
{
	struct integrity_iint_cache *iint;

	if (!IS_IMA(inode))
		return NULL;

	read_lock(&integrity_iint_lock);
	iint = __integrity_iint_find(inode);
	read_unlock(&integrity_iint_lock);

	return iint;
}

static void iint_free(struct integrity_iint_cache *iint)
{
	iint->version = 0;
	iint->flags = 0UL;
	iint->ima_file_status = INTEGRITY_UNKNOWN;
	iint->ima_mmap_status = INTEGRITY_UNKNOWN;
	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
	iint->ima_module_status = INTEGRITY_UNKNOWN;
	iint->evm_status = INTEGRITY_UNKNOWN;
	kmem_cache_free(iint_cache, iint);
}

/**
 * integrity_inode_get - find or allocate an iint associated with an inode
 * @inode: pointer to the inode
 * @return: allocated iint
 *
 * Caller must lock i_mutex
 */
struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
{
	struct rb_node **p;
	struct rb_node *node, *parent = NULL;
	struct integrity_iint_cache *iint, *test_iint;

	iint = integrity_iint_find(inode);
	if (iint)
		return iint;

	iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
	if (!iint)
		return NULL;

	write_lock(&integrity_iint_lock);

	p = &integrity_iint_tree.rb_node;
	while (*p) {
		parent = *p;
		test_iint = rb_entry(parent, struct integrity_iint_cache,
				     rb_node);
		if (inode < test_iint->inode)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	iint->inode = inode;
	node = &iint->rb_node;
	inode->i_flags |= S_IMA;
	rb_link_node(node, parent, p);
	rb_insert_color(node, &integrity_iint_tree);

	write_unlock(&integrity_iint_lock);
	return iint;
}

/**
 * integrity_inode_free - called on security_inode_free
 * @inode: pointer to the inode
 *
 * Free the integrity information(iint) associated with an inode.
 */
void integrity_inode_free(struct inode *inode)
{
	struct integrity_iint_cache *iint;

	if (!IS_IMA(inode))
		return;

	write_lock(&integrity_iint_lock);
	iint = __integrity_iint_find(inode);
	rb_erase(&iint->rb_node, &integrity_iint_tree);
	write_unlock(&integrity_iint_lock);

	iint_free(iint);
}

static void init_once(void *foo)
{
	struct integrity_iint_cache *iint = foo;

	memset(iint, 0, sizeof *iint);
	iint->version = 0;
	iint->flags = 0UL;
	iint->ima_file_status = INTEGRITY_UNKNOWN;
	iint->ima_mmap_status = INTEGRITY_UNKNOWN;
	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
	iint->ima_module_status = INTEGRITY_UNKNOWN;
	iint->evm_status = INTEGRITY_UNKNOWN;
}

static int __init integrity_iintcache_init(void)
{
	iint_cache =
	    kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
			      0, SLAB_PANIC, init_once);
	iint_initialized = 1;
	return 0;
}
security_initcall(integrity_iintcache_init);
Commit	Line	Data
f381c272 MZ	1	/*
	2	* Copyright (C) 2008 IBM Corporation
	3	*
	4	* Authors:
	5	* Mimi Zohar <zohar@us.ibm.com>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License as
	9	* published by the Free Software Foundation, version 2 of the
	10	* License.
	11	*
	12	* File: integrity_iint.c
	13	* - implements the integrity hooks: integrity_inode_alloc,
	14	* integrity_inode_free
	15	* - cache integrity information associated with an inode
	16	* using a rbtree tree.
	17	*/
	18	#include <linux/slab.h>
	19	#include <linux/module.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/rbtree.h>
	22	#include "integrity.h"
	23
	24	static struct rb_root integrity_iint_tree = RB_ROOT;
a10bf26b	25	static DEFINE_RWLOCK(integrity_iint_lock);
f381c272 MZ	26	static struct kmem_cache *iint_cache __read_mostly;
	27
	28	int iint_initialized;
	29
	30	/*
	31	* __integrity_iint_find - return the iint associated with an inode
	32	*/
	33	static struct integrity_iint_cache __integrity_iint_find(struct inode inode)
	34	{
	35	struct integrity_iint_cache *iint;
	36	struct rb_node *n = integrity_iint_tree.rb_node;
	37
f381c272 MZ	38	while (n) {
	39	iint = rb_entry(n, struct integrity_iint_cache, rb_node);
	40
	41	if (inode < iint->inode)
	42	n = n->rb_left;
	43	else if (inode > iint->inode)
	44	n = n->rb_right;
	45	else
	46	break;
	47	}
	48	if (!n)
	49	return NULL;
	50
	51	return iint;
	52	}
	53
	54	/*
	55	* integrity_iint_find - return the iint associated with an inode
	56	*/
	57	struct integrity_iint_cache integrity_iint_find(struct inode inode)
	58	{
	59	struct integrity_iint_cache *iint;
	60
	61	if (!IS_IMA(inode))
	62	return NULL;
	63
a10bf26b	64	read_lock(&integrity_iint_lock);
f381c272	65	iint = __integrity_iint_find(inode);
a10bf26b	66	read_unlock(&integrity_iint_lock);
f381c272 MZ	67
	68	return iint;
	69	}
	70
	71	static void iint_free(struct integrity_iint_cache *iint)
	72	{
	73	iint->version = 0;
	74	iint->flags = 0UL;
d79d72e0 MZ	75	iint->ima_file_status = INTEGRITY_UNKNOWN;
	76	iint->ima_mmap_status = INTEGRITY_UNKNOWN;
	77	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
	78	iint->ima_module_status = INTEGRITY_UNKNOWN;
fb788d8b	79	iint->evm_status = INTEGRITY_UNKNOWN;
f381c272 MZ	80	kmem_cache_free(iint_cache, iint);
	81	}
	82
	83	/**
bf2276d1	84	* integrity_inode_get - find or allocate an iint associated with an inode
f381c272	85	* @inode: pointer to the inode
bf2276d1 DK	86	* @return: allocated iint
	87	*
	88	* Caller must lock i_mutex
f381c272	89	*/
bf2276d1	90	struct integrity_iint_cache integrity_inode_get(struct inode inode)
f381c272 MZ	91	{
f381c272 MZ	92	struct rb_node **p;
bf2276d1 DK	93	struct rb_node node, parent = NULL;
bf2276d1 DK	94	struct integrity_iint_cache iint, test_iint;
f381c272	95
bf2276d1 DK	96	iint = integrity_iint_find(inode);
	97	if (iint)
	98	return iint;
f381c272	99
bf2276d1 DK	100	iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
	101	if (!iint)
	102	return NULL;
f381c272	103
a10bf26b	104	write_lock(&integrity_iint_lock);
f381c272 MZ	105
	106	p = &integrity_iint_tree.rb_node;
	107	while (*p) {
	108	parent = *p;
	109	test_iint = rb_entry(parent, struct integrity_iint_cache,
	110	rb_node);
f381c272 MZ	111	if (inode < test_iint->inode)
f381c272 MZ	112	p = &(*p)->rb_left;
f381c272	113	else
bf2276d1	114	p = &(*p)->rb_right;
f381c272 MZ	115	}
f381c272 MZ	116
bf2276d1 DK	117	iint->inode = inode;
bf2276d1 DK	118	node = &iint->rb_node;
f381c272	119	inode->i_flags \|= S_IMA;
bf2276d1 DK	120	rb_link_node(node, parent, p);
bf2276d1 DK	121	rb_insert_color(node, &integrity_iint_tree);
f381c272	122
a10bf26b	123	write_unlock(&integrity_iint_lock);
bf2276d1	124	return iint;
f381c272 MZ	125	}
	126
	127	/**
	128	* integrity_inode_free - called on security_inode_free
	129	* @inode: pointer to the inode
	130	*
	131	* Free the integrity information(iint) associated with an inode.
	132	*/
	133	void integrity_inode_free(struct inode *inode)
	134	{
	135	struct integrity_iint_cache *iint;
	136
	137	if (!IS_IMA(inode))
	138	return;
	139
a10bf26b	140	write_lock(&integrity_iint_lock);
f381c272 MZ	141	iint = __integrity_iint_find(inode);
f381c272 MZ	142	rb_erase(&iint->rb_node, &integrity_iint_tree);
a10bf26b	143	write_unlock(&integrity_iint_lock);
f381c272 MZ	144
	145	iint_free(iint);
	146	}
	147
	148	static void init_once(void *foo)
	149	{
	150	struct integrity_iint_cache *iint = foo;
	151
	152	memset(iint, 0, sizeof *iint);
	153	iint->version = 0;
	154	iint->flags = 0UL;
d79d72e0 MZ	155	iint->ima_file_status = INTEGRITY_UNKNOWN;
	156	iint->ima_mmap_status = INTEGRITY_UNKNOWN;
	157	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
	158	iint->ima_module_status = INTEGRITY_UNKNOWN;
24e0198e	159	iint->evm_status = INTEGRITY_UNKNOWN;
f381c272 MZ	160	}
	161
	162	static int __init integrity_iintcache_init(void)
	163	{
	164	iint_cache =
	165	kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
	166	0, SLAB_PANIC, init_once);
	167	iint_initialized = 1;
	168	return 0;
	169	}
	170	security_initcall(integrity_iintcache_init);