blob: fa592ff1ac1c4f7b24394baf6a2155dc1fb911a6 [file] [log] [blame]
Mimi Zohar3323eec2009-02-04 09:06:58 -05001/*
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: ima_iint.c
13 * - implements the IMA hooks: ima_inode_alloc, ima_inode_free
14 * - cache integrity information associated with an inode
15 * using a radix tree.
16 */
17#include <linux/module.h>
18#include <linux/spinlock.h>
19#include <linux/radix-tree.h>
20#include "ima.h"
21
Mimi Zohar3323eec2009-02-04 09:06:58 -050022RADIX_TREE(ima_iint_store, GFP_ATOMIC);
23DEFINE_SPINLOCK(ima_iint_lock);
24
25static struct kmem_cache *iint_cache __read_mostly;
26
27/* ima_iint_find_get - return the iint associated with an inode
28 *
29 * ima_iint_find_get gets a reference to the iint. Caller must
30 * remember to put the iint reference.
31 */
32struct ima_iint_cache *ima_iint_find_get(struct inode *inode)
33{
34 struct ima_iint_cache *iint;
35
36 rcu_read_lock();
37 iint = radix_tree_lookup(&ima_iint_store, (unsigned long)inode);
38 if (!iint)
39 goto out;
40 kref_get(&iint->refcount);
41out:
42 rcu_read_unlock();
43 return iint;
44}
45
Eric Paris93533842009-12-04 15:47:52 -050046/**
47 * ima_inode_alloc - allocate an iint associated with an inode
48 * @inode: pointer to the inode
Mimi Zohar3323eec2009-02-04 09:06:58 -050049 */
Eric Paris93533842009-12-04 15:47:52 -050050int ima_inode_alloc(struct inode *inode)
Mimi Zohar3323eec2009-02-04 09:06:58 -050051{
52 struct ima_iint_cache *iint = NULL;
53 int rc = 0;
54
55 if (!ima_initialized)
Eric Paris93533842009-12-04 15:47:52 -050056 return 0;
57
Mimi Zoharc09c59e2009-11-18 16:16:06 -050058 iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
Mimi Zohar3323eec2009-02-04 09:06:58 -050059 if (!iint)
Eric Paris93533842009-12-04 15:47:52 -050060 return -ENOMEM;
Mimi Zohar3323eec2009-02-04 09:06:58 -050061
Mimi Zoharc09c59e2009-11-18 16:16:06 -050062 rc = radix_tree_preload(GFP_NOFS);
Mimi Zohar3323eec2009-02-04 09:06:58 -050063 if (rc < 0)
64 goto out;
65
66 spin_lock(&ima_iint_lock);
67 rc = radix_tree_insert(&ima_iint_store, (unsigned long)inode, iint);
68 spin_unlock(&ima_iint_lock);
69out:
Eric Paris93533842009-12-04 15:47:52 -050070 if (rc < 0)
Mimi Zohar3323eec2009-02-04 09:06:58 -050071 kmem_cache_free(iint_cache, iint);
Eric Paris93533842009-12-04 15:47:52 -050072
Mimi Zohar3323eec2009-02-04 09:06:58 -050073 radix_tree_preload_end();
Eric Paris93533842009-12-04 15:47:52 -050074
75 return rc;
Mimi Zohar3323eec2009-02-04 09:06:58 -050076}
77
Mimi Zohar3323eec2009-02-04 09:06:58 -050078/* iint_free - called when the iint refcount goes to zero */
79void iint_free(struct kref *kref)
80{
81 struct ima_iint_cache *iint = container_of(kref, struct ima_iint_cache,
82 refcount);
83 iint->version = 0;
84 iint->flags = 0UL;
Mimi Zohar1df9f0a2009-02-04 09:07:02 -050085 if (iint->readcount != 0) {
86 printk(KERN_INFO "%s: readcount: %ld\n", __FUNCTION__,
87 iint->readcount);
88 iint->readcount = 0;
89 }
90 if (iint->writecount != 0) {
91 printk(KERN_INFO "%s: writecount: %ld\n", __FUNCTION__,
92 iint->writecount);
93 iint->writecount = 0;
94 }
95 if (iint->opencount != 0) {
96 printk(KERN_INFO "%s: opencount: %ld\n", __FUNCTION__,
97 iint->opencount);
98 iint->opencount = 0;
99 }
Mimi Zohar3323eec2009-02-04 09:06:58 -0500100 kref_set(&iint->refcount, 1);
101 kmem_cache_free(iint_cache, iint);
102}
103
104void iint_rcu_free(struct rcu_head *rcu_head)
105{
106 struct ima_iint_cache *iint = container_of(rcu_head,
107 struct ima_iint_cache, rcu);
108 kref_put(&iint->refcount, iint_free);
109}
110
111/**
Eric Paris85a17f52009-12-04 15:48:08 -0500112 * ima_inode_free - called on security_inode_free
Mimi Zohar3323eec2009-02-04 09:06:58 -0500113 * @inode: pointer to the inode
114 *
115 * Free the integrity information(iint) associated with an inode.
116 */
Eric Paris85a17f52009-12-04 15:48:08 -0500117void ima_inode_free(struct inode *inode)
Mimi Zohar3323eec2009-02-04 09:06:58 -0500118{
119 struct ima_iint_cache *iint;
120
121 if (!ima_initialized)
122 return;
123 spin_lock(&ima_iint_lock);
124 iint = radix_tree_delete(&ima_iint_store, (unsigned long)inode);
125 spin_unlock(&ima_iint_lock);
126 if (iint)
127 call_rcu(&iint->rcu, iint_rcu_free);
128}
129
130static void init_once(void *foo)
131{
132 struct ima_iint_cache *iint = foo;
133
134 memset(iint, 0, sizeof *iint);
135 iint->version = 0;
136 iint->flags = 0UL;
137 mutex_init(&iint->mutex);
138 iint->readcount = 0;
139 iint->writecount = 0;
Mimi Zohar1df9f0a2009-02-04 09:07:02 -0500140 iint->opencount = 0;
Mimi Zohar3323eec2009-02-04 09:06:58 -0500141 kref_set(&iint->refcount, 1);
142}
143
Eric Paris932995f2009-05-21 15:43:32 -0400144void __init ima_iintcache_init(void)
Mimi Zohar3323eec2009-02-04 09:06:58 -0500145{
146 iint_cache =
147 kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
148 SLAB_PANIC, init_once);
149}