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1/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2003 Erez Zadok
5 * Copyright (C) 2001-2003 Stony Brook University
6 * Copyright (C) 2004-2006 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompson <mcthomps@us.ibm.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 * 02111-1307, USA.
24 */
25
26#include <linux/fs.h>
27#include <linux/mount.h>
28#include <linux/key.h>
29#include <linux/slab.h>
30#include <linux/seq_file.h>
31#include <linux/file.h>
32#include <linux/crypto.h>
33#include "ecryptfs_kernel.h"
34
35struct kmem_cache *ecryptfs_inode_info_cache;
36
37/**
38 * ecryptfs_alloc_inode - allocate an ecryptfs inode
39 * @sb: Pointer to the ecryptfs super block
40 *
41 * Called to bring an inode into existence.
42 *
43 * Only handle allocation, setting up structures should be done in
44 * ecryptfs_read_inode. This is because the kernel, between now and
45 * then, will 0 out the private data pointer.
46 *
47 * Returns a pointer to a newly allocated inode, NULL otherwise
48 */
49static struct inode *ecryptfs_alloc_inode(struct super_block *sb)
50{
51 struct ecryptfs_inode_info *inode_info;
52 struct inode *inode = NULL;
53
54 inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);
55 if (unlikely(!inode_info))
56 goto out;
57 ecryptfs_init_crypt_stat(&inode_info->crypt_stat);
58 mutex_init(&inode_info->lower_file_mutex);
59 atomic_set(&inode_info->lower_file_count, 0);
60 inode_info->lower_file = NULL;
61 inode = &inode_info->vfs_inode;
62out:
63 return inode;
64}
65
66static void ecryptfs_i_callback(struct rcu_head *head)
67{
68 struct inode *inode = container_of(head, struct inode, i_rcu);
69 struct ecryptfs_inode_info *inode_info;
70 inode_info = ecryptfs_inode_to_private(inode);
71
72 INIT_LIST_HEAD(&inode->i_dentry);
73 kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
74}
75
76/**
77 * ecryptfs_destroy_inode
78 * @inode: The ecryptfs inode
79 *
80 * This is used during the final destruction of the inode. All
81 * allocation of memory related to the inode, including allocated
82 * memory in the crypt_stat struct, will be released here.
83 * There should be no chance that this deallocation will be missed.
84 */
85static void ecryptfs_destroy_inode(struct inode *inode)
86{
87 struct ecryptfs_inode_info *inode_info;
88
89 inode_info = ecryptfs_inode_to_private(inode);
90 BUG_ON(inode_info->lower_file);
91 ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
92 call_rcu(&inode->i_rcu, ecryptfs_i_callback);
93}
94
95/**
96 * ecryptfs_statfs
97 * @sb: The ecryptfs super block
98 * @buf: The struct kstatfs to fill in with stats
99 *
100 * Get the filesystem statistics. Currently, we let this pass right through
101 * to the lower filesystem and take no action ourselves.
102 */
103static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf)
104{
105 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
106
107 if (!lower_dentry->d_sb->s_op->statfs)
108 return -ENOSYS;
109 return lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
110}
111
112/**
113 * ecryptfs_evict_inode
114 * @inode - The ecryptfs inode
115 *
116 * Called by iput() when the inode reference count reached zero
117 * and the inode is not hashed anywhere. Used to clear anything
118 * that needs to be, before the inode is completely destroyed and put
119 * on the inode free list. We use this to drop out reference to the
120 * lower inode.
121 */
122static void ecryptfs_evict_inode(struct inode *inode)
123{
124 truncate_inode_pages(&inode->i_data, 0);
125 end_writeback(inode);
126 iput(ecryptfs_inode_to_lower(inode));
127}
128
129/**
130 * ecryptfs_show_options
131 *
132 * Prints the mount options for a given superblock.
133 * Returns zero; does not fail.
134 */
135static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt)
136{
137 struct super_block *sb = mnt->mnt_sb;
138 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
139 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
140 struct ecryptfs_global_auth_tok *walker;
141
142 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
143 list_for_each_entry(walker,
144 &mount_crypt_stat->global_auth_tok_list,
145 mount_crypt_stat_list) {
146 if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK)
147 seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig);
148 else
149 seq_printf(m, ",ecryptfs_sig=%s", walker->sig);
150 }
151 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
152
153 seq_printf(m, ",ecryptfs_cipher=%s",
154 mount_crypt_stat->global_default_cipher_name);
155
156 if (mount_crypt_stat->global_default_cipher_key_size)
157 seq_printf(m, ",ecryptfs_key_bytes=%zd",
158 mount_crypt_stat->global_default_cipher_key_size);
159 if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)
160 seq_printf(m, ",ecryptfs_passthrough");
161 if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
162 seq_printf(m, ",ecryptfs_xattr_metadata");
163 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
164 seq_printf(m, ",ecryptfs_encrypted_view");
165 if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS)
166 seq_printf(m, ",ecryptfs_unlink_sigs");
167 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
168 seq_printf(m, ",ecryptfs_mount_auth_tok_only");
169
170 return 0;
171}
172
173const struct super_operations ecryptfs_sops = {
174 .alloc_inode = ecryptfs_alloc_inode,
175 .destroy_inode = ecryptfs_destroy_inode,
176 .drop_inode = generic_drop_inode,
177 .statfs = ecryptfs_statfs,
178 .remount_fs = NULL,
179 .evict_inode = ecryptfs_evict_inode,
180 .show_options = ecryptfs_show_options
181};
1/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2003 Erez Zadok
5 * Copyright (C) 2001-2003 Stony Brook University
6 * Copyright (C) 2004-2006 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompson <mcthomps@us.ibm.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 * 02111-1307, USA.
24 */
25
26#include <linux/fs.h>
27#include <linux/mount.h>
28#include <linux/key.h>
29#include <linux/slab.h>
30#include <linux/seq_file.h>
31#include <linux/file.h>
32#include <linux/statfs.h>
33#include <linux/magic.h>
34#include "ecryptfs_kernel.h"
35
36struct kmem_cache *ecryptfs_inode_info_cache;
37
38/**
39 * ecryptfs_alloc_inode - allocate an ecryptfs inode
40 * @sb: Pointer to the ecryptfs super block
41 *
42 * Called to bring an inode into existence.
43 *
44 * Only handle allocation, setting up structures should be done in
45 * ecryptfs_read_inode. This is because the kernel, between now and
46 * then, will 0 out the private data pointer.
47 *
48 * Returns a pointer to a newly allocated inode, NULL otherwise
49 */
50static struct inode *ecryptfs_alloc_inode(struct super_block *sb)
51{
52 struct ecryptfs_inode_info *inode_info;
53 struct inode *inode = NULL;
54
55 inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);
56 if (unlikely(!inode_info))
57 goto out;
58 ecryptfs_init_crypt_stat(&inode_info->crypt_stat);
59 mutex_init(&inode_info->lower_file_mutex);
60 atomic_set(&inode_info->lower_file_count, 0);
61 inode_info->lower_file = NULL;
62 inode = &inode_info->vfs_inode;
63out:
64 return inode;
65}
66
67static void ecryptfs_i_callback(struct rcu_head *head)
68{
69 struct inode *inode = container_of(head, struct inode, i_rcu);
70 struct ecryptfs_inode_info *inode_info;
71 inode_info = ecryptfs_inode_to_private(inode);
72
73 kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
74}
75
76/**
77 * ecryptfs_destroy_inode
78 * @inode: The ecryptfs inode
79 *
80 * This is used during the final destruction of the inode. All
81 * allocation of memory related to the inode, including allocated
82 * memory in the crypt_stat struct, will be released here.
83 * There should be no chance that this deallocation will be missed.
84 */
85static void ecryptfs_destroy_inode(struct inode *inode)
86{
87 struct ecryptfs_inode_info *inode_info;
88
89 inode_info = ecryptfs_inode_to_private(inode);
90 BUG_ON(inode_info->lower_file);
91 ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
92 call_rcu(&inode->i_rcu, ecryptfs_i_callback);
93}
94
95/**
96 * ecryptfs_statfs
97 * @sb: The ecryptfs super block
98 * @buf: The struct kstatfs to fill in with stats
99 *
100 * Get the filesystem statistics. Currently, we let this pass right through
101 * to the lower filesystem and take no action ourselves.
102 */
103static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf)
104{
105 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
106 int rc;
107
108 if (!lower_dentry->d_sb->s_op->statfs)
109 return -ENOSYS;
110
111 rc = lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
112 if (rc)
113 return rc;
114
115 buf->f_type = ECRYPTFS_SUPER_MAGIC;
116 rc = ecryptfs_set_f_namelen(&buf->f_namelen, buf->f_namelen,
117 &ecryptfs_superblock_to_private(dentry->d_sb)->mount_crypt_stat);
118
119 return rc;
120}
121
122/**
123 * ecryptfs_evict_inode
124 * @inode - The ecryptfs inode
125 *
126 * Called by iput() when the inode reference count reached zero
127 * and the inode is not hashed anywhere. Used to clear anything
128 * that needs to be, before the inode is completely destroyed and put
129 * on the inode free list. We use this to drop out reference to the
130 * lower inode.
131 */
132static void ecryptfs_evict_inode(struct inode *inode)
133{
134 truncate_inode_pages_final(&inode->i_data);
135 clear_inode(inode);
136 iput(ecryptfs_inode_to_lower(inode));
137}
138
139/**
140 * ecryptfs_show_options
141 *
142 * Prints the mount options for a given superblock.
143 * Returns zero; does not fail.
144 */
145static int ecryptfs_show_options(struct seq_file *m, struct dentry *root)
146{
147 struct super_block *sb = root->d_sb;
148 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
149 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
150 struct ecryptfs_global_auth_tok *walker;
151
152 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
153 list_for_each_entry(walker,
154 &mount_crypt_stat->global_auth_tok_list,
155 mount_crypt_stat_list) {
156 if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK)
157 seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig);
158 else
159 seq_printf(m, ",ecryptfs_sig=%s", walker->sig);
160 }
161 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
162
163 seq_printf(m, ",ecryptfs_cipher=%s",
164 mount_crypt_stat->global_default_cipher_name);
165
166 if (mount_crypt_stat->global_default_cipher_key_size)
167 seq_printf(m, ",ecryptfs_key_bytes=%zd",
168 mount_crypt_stat->global_default_cipher_key_size);
169 if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)
170 seq_printf(m, ",ecryptfs_passthrough");
171 if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
172 seq_printf(m, ",ecryptfs_xattr_metadata");
173 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
174 seq_printf(m, ",ecryptfs_encrypted_view");
175 if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS)
176 seq_printf(m, ",ecryptfs_unlink_sigs");
177 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
178 seq_printf(m, ",ecryptfs_mount_auth_tok_only");
179
180 return 0;
181}
182
183const struct super_operations ecryptfs_sops = {
184 .alloc_inode = ecryptfs_alloc_inode,
185 .destroy_inode = ecryptfs_destroy_inode,
186 .statfs = ecryptfs_statfs,
187 .remount_fs = NULL,
188 .evict_inode = ecryptfs_evict_inode,
189 .show_options = ecryptfs_show_options
190};