2 * Copyright (C) 2008 IBM Corporation
5 * Mimi Zohar <zohar@us.ibm.com>
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
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.
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/spinlock.h>
21 #include <linux/rbtree.h>
22 #include "integrity.h"
24 static struct rb_root integrity_iint_tree = RB_ROOT;
25 static DEFINE_RWLOCK(integrity_iint_lock);
26 static struct kmem_cache *iint_cache __read_mostly;
31 * __integrity_iint_find - return the iint associated with an inode
33 static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
35 struct integrity_iint_cache *iint;
36 struct rb_node *n = integrity_iint_tree.rb_node;
39 iint = rb_entry(n, struct integrity_iint_cache, rb_node);
41 if (inode < iint->inode)
43 else if (inode > iint->inode)
55 * integrity_iint_find - return the iint associated with an inode
57 struct integrity_iint_cache *integrity_iint_find(struct inode *inode)
59 struct integrity_iint_cache *iint;
64 read_lock(&integrity_iint_lock);
65 iint = __integrity_iint_find(inode);
66 read_unlock(&integrity_iint_lock);
71 static void iint_free(struct integrity_iint_cache *iint)
75 iint->ima_status = INTEGRITY_UNKNOWN;
76 iint->evm_status = INTEGRITY_UNKNOWN;
77 kmem_cache_free(iint_cache, iint);
81 * integrity_inode_get - find or allocate an iint associated with an inode
82 * @inode: pointer to the inode
83 * @return: allocated iint
85 * Caller must lock i_mutex
87 struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
90 struct rb_node *node, *parent = NULL;
91 struct integrity_iint_cache *iint, *test_iint;
93 iint = integrity_iint_find(inode);
97 iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
101 write_lock(&integrity_iint_lock);
103 p = &integrity_iint_tree.rb_node;
106 test_iint = rb_entry(parent, struct integrity_iint_cache,
108 if (inode < test_iint->inode)
115 node = &iint->rb_node;
116 inode->i_flags |= S_IMA;
117 rb_link_node(node, parent, p);
118 rb_insert_color(node, &integrity_iint_tree);
120 write_unlock(&integrity_iint_lock);
125 * integrity_inode_free - called on security_inode_free
126 * @inode: pointer to the inode
128 * Free the integrity information(iint) associated with an inode.
130 void integrity_inode_free(struct inode *inode)
132 struct integrity_iint_cache *iint;
137 write_lock(&integrity_iint_lock);
138 iint = __integrity_iint_find(inode);
139 rb_erase(&iint->rb_node, &integrity_iint_tree);
140 write_unlock(&integrity_iint_lock);
145 static void init_once(void *foo)
147 struct integrity_iint_cache *iint = foo;
149 memset(iint, 0, sizeof *iint);
152 iint->ima_status = INTEGRITY_UNKNOWN;
153 iint->evm_status = INTEGRITY_UNKNOWN;
156 static int __init integrity_iintcache_init(void)
159 kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
160 0, SLAB_PANIC, init_once);
161 iint_initialized = 1;
164 security_initcall(integrity_iintcache_init);