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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; |
25 | static DEFINE_RWLOCK(integrity_iint_lock); |
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 | |
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 | |
64 | read_lock(&integrity_iint_lock); |
65 | iint = __integrity_iint_find(inode); |
66 | read_unlock(&integrity_iint_lock); |
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; |
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; |
79 | iint->evm_status = INTEGRITY_UNKNOWN; |
80 | kmem_cache_free(iint_cache, iint); |
81 | } |
82 | |
83 | /** |
84 | * integrity_inode_get - find or allocate an iint associated with an inode |
85 | * @inode: pointer to the inode |
86 | * @return: allocated iint |
87 | * |
88 | * Caller must lock i_mutex |
89 | */ |
90 | struct integrity_iint_cache *integrity_inode_get(struct inode *inode) |
91 | { |
92 | struct rb_node **p; |
93 | struct rb_node *node, *parent = NULL; |
94 | struct integrity_iint_cache *iint, *test_iint; |
95 | |
96 | iint = integrity_iint_find(inode); |
97 | if (iint) |
98 | return iint; |
99 | |
100 | iint = kmem_cache_alloc(iint_cache, GFP_NOFS); |
101 | if (!iint) |
102 | return NULL; |
103 | |
104 | write_lock(&integrity_iint_lock); |
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); |
111 | if (inode < test_iint->inode) |
112 | p = &(*p)->rb_left; |
113 | else |
114 | p = &(*p)->rb_right; |
115 | } |
116 | |
117 | iint->inode = inode; |
118 | node = &iint->rb_node; |
119 | inode->i_flags |= S_IMA; |
120 | rb_link_node(node, parent, p); |
121 | rb_insert_color(node, &integrity_iint_tree); |
122 | |
123 | write_unlock(&integrity_iint_lock); |
124 | return iint; |
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 | |
140 | write_lock(&integrity_iint_lock); |
141 | iint = __integrity_iint_find(inode); |
142 | rb_erase(&iint->rb_node, &integrity_iint_tree); |
143 | write_unlock(&integrity_iint_lock); |
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; |
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; |
159 | iint->evm_status = INTEGRITY_UNKNOWN; |
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); |
171 |
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od-2011-09-04
od-2011-09-18
v2.6.34-rc5
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