Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 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; |
Dmitry Kasatkin | a10bf26 | 2012-02-08 14:15:42 -0500 | [diff] [blame^] | 25 | static DEFINE_RWLOCK(integrity_iint_lock); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 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 | |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 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 | |
Dmitry Kasatkin | a10bf26 | 2012-02-08 14:15:42 -0500 | [diff] [blame^] | 64 | read_lock(&integrity_iint_lock); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 65 | iint = __integrity_iint_find(inode); |
Dmitry Kasatkin | a10bf26 | 2012-02-08 14:15:42 -0500 | [diff] [blame^] | 66 | read_unlock(&integrity_iint_lock); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 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; |
Mimi Zohar | 2fe5d6d | 2012-02-13 10:15:05 -0500 | [diff] [blame] | 75 | iint->ima_status = INTEGRITY_UNKNOWN; |
Dmitry Kasatkin | fb788d8 | 2011-08-15 15:30:11 +0300 | [diff] [blame] | 76 | iint->evm_status = INTEGRITY_UNKNOWN; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 77 | kmem_cache_free(iint_cache, iint); |
| 78 | } |
| 79 | |
| 80 | /** |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 81 | * integrity_inode_get - find or allocate an iint associated with an inode |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 82 | * @inode: pointer to the inode |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 83 | * @return: allocated iint |
| 84 | * |
| 85 | * Caller must lock i_mutex |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 86 | */ |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 87 | struct integrity_iint_cache *integrity_inode_get(struct inode *inode) |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 88 | { |
| 89 | struct rb_node **p; |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 90 | struct rb_node *node, *parent = NULL; |
| 91 | struct integrity_iint_cache *iint, *test_iint; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 92 | |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 93 | iint = integrity_iint_find(inode); |
| 94 | if (iint) |
| 95 | return iint; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 96 | |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 97 | iint = kmem_cache_alloc(iint_cache, GFP_NOFS); |
| 98 | if (!iint) |
| 99 | return NULL; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 100 | |
Dmitry Kasatkin | a10bf26 | 2012-02-08 14:15:42 -0500 | [diff] [blame^] | 101 | write_lock(&integrity_iint_lock); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 102 | |
| 103 | p = &integrity_iint_tree.rb_node; |
| 104 | while (*p) { |
| 105 | parent = *p; |
| 106 | test_iint = rb_entry(parent, struct integrity_iint_cache, |
| 107 | rb_node); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 108 | if (inode < test_iint->inode) |
| 109 | p = &(*p)->rb_left; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 110 | else |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 111 | p = &(*p)->rb_right; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 112 | } |
| 113 | |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 114 | iint->inode = inode; |
| 115 | node = &iint->rb_node; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 116 | inode->i_flags |= S_IMA; |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 117 | rb_link_node(node, parent, p); |
| 118 | rb_insert_color(node, &integrity_iint_tree); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 119 | |
Dmitry Kasatkin | a10bf26 | 2012-02-08 14:15:42 -0500 | [diff] [blame^] | 120 | write_unlock(&integrity_iint_lock); |
Dmitry Kasatkin | bf2276d | 2011-10-19 12:04:40 +0300 | [diff] [blame] | 121 | return iint; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 122 | } |
| 123 | |
| 124 | /** |
| 125 | * integrity_inode_free - called on security_inode_free |
| 126 | * @inode: pointer to the inode |
| 127 | * |
| 128 | * Free the integrity information(iint) associated with an inode. |
| 129 | */ |
| 130 | void integrity_inode_free(struct inode *inode) |
| 131 | { |
| 132 | struct integrity_iint_cache *iint; |
| 133 | |
| 134 | if (!IS_IMA(inode)) |
| 135 | return; |
| 136 | |
Dmitry Kasatkin | a10bf26 | 2012-02-08 14:15:42 -0500 | [diff] [blame^] | 137 | write_lock(&integrity_iint_lock); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 138 | iint = __integrity_iint_find(inode); |
| 139 | rb_erase(&iint->rb_node, &integrity_iint_tree); |
Dmitry Kasatkin | a10bf26 | 2012-02-08 14:15:42 -0500 | [diff] [blame^] | 140 | write_unlock(&integrity_iint_lock); |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 141 | |
| 142 | iint_free(iint); |
| 143 | } |
| 144 | |
| 145 | static void init_once(void *foo) |
| 146 | { |
| 147 | struct integrity_iint_cache *iint = foo; |
| 148 | |
| 149 | memset(iint, 0, sizeof *iint); |
| 150 | iint->version = 0; |
| 151 | iint->flags = 0UL; |
Mimi Zohar | 2fe5d6d | 2012-02-13 10:15:05 -0500 | [diff] [blame] | 152 | iint->ima_status = INTEGRITY_UNKNOWN; |
Dmitry Kasatkin | 24e0198 | 2011-05-06 11:34:17 +0300 | [diff] [blame] | 153 | iint->evm_status = INTEGRITY_UNKNOWN; |
Mimi Zohar | f381c27 | 2011-03-09 14:13:22 -0500 | [diff] [blame] | 154 | } |
| 155 | |
| 156 | static int __init integrity_iintcache_init(void) |
| 157 | { |
| 158 | iint_cache = |
| 159 | kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache), |
| 160 | 0, SLAB_PANIC, init_once); |
| 161 | iint_initialized = 1; |
| 162 | return 0; |
| 163 | } |
| 164 | security_initcall(integrity_iintcache_init); |