Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1 | /** |
| 2 | * eCryptfs: Linux filesystem encryption layer |
| 3 | * This is where eCryptfs coordinates the symmetric encryption and |
| 4 | * decryption of the file data as it passes between the lower |
| 5 | * encrypted file and the upper decrypted file. |
| 6 | * |
| 7 | * Copyright (C) 1997-2003 Erez Zadok |
| 8 | * Copyright (C) 2001-2003 Stony Brook University |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 9 | * Copyright (C) 2004-2007 International Business Machines Corp. |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 10 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or |
| 13 | * modify it under the terms of the GNU General Public License as |
| 14 | * published by the Free Software Foundation; either version 2 of the |
| 15 | * License, or (at your option) any later version. |
| 16 | * |
| 17 | * This program is distributed in the hope that it will be useful, but |
| 18 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 20 | * General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with this program; if not, write to the Free Software |
| 24 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| 25 | * 02111-1307, USA. |
| 26 | */ |
| 27 | |
| 28 | #include <linux/pagemap.h> |
| 29 | #include <linux/writeback.h> |
| 30 | #include <linux/page-flags.h> |
| 31 | #include <linux/mount.h> |
| 32 | #include <linux/file.h> |
| 33 | #include <linux/crypto.h> |
| 34 | #include <linux/scatterlist.h> |
Harvey Harrison | 0a688ad | 2008-07-23 21:30:07 -0700 | [diff] [blame] | 35 | #include <asm/unaligned.h> |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 36 | #include "ecryptfs_kernel.h" |
| 37 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 38 | /** |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 39 | * ecryptfs_get_locked_page |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 40 | * |
| 41 | * Get one page from cache or lower f/s, return error otherwise. |
| 42 | * |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 43 | * Returns locked and up-to-date page (if ok), with increased |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 44 | * refcnt. |
| 45 | */ |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 46 | struct page *ecryptfs_get_locked_page(struct file *file, loff_t index) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 47 | { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 48 | struct dentry *dentry; |
| 49 | struct inode *inode; |
| 50 | struct address_space *mapping; |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 51 | struct page *page; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 52 | |
Josef "Jeff" Sipek | bd243a4 | 2006-12-08 02:36:48 -0800 | [diff] [blame] | 53 | dentry = file->f_path.dentry; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 54 | inode = dentry->d_inode; |
| 55 | mapping = inode->i_mapping; |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 56 | page = read_mapping_page(mapping, index, (void *)file); |
| 57 | if (!IS_ERR(page)) |
| 58 | lock_page(page); |
| 59 | return page; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 60 | } |
| 61 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 62 | /** |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 63 | * ecryptfs_writepage |
| 64 | * @page: Page that is locked before this call is made |
| 65 | * |
| 66 | * Returns zero on success; non-zero otherwise |
| 67 | */ |
| 68 | static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc) |
| 69 | { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 70 | int rc; |
| 71 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 72 | rc = ecryptfs_encrypt_page(page); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 73 | if (rc) { |
| 74 | ecryptfs_printk(KERN_WARNING, "Error encrypting " |
| 75 | "page (upper index [0x%.16x])\n", page->index); |
| 76 | ClearPageUptodate(page); |
| 77 | goto out; |
| 78 | } |
| 79 | SetPageUptodate(page); |
| 80 | unlock_page(page); |
| 81 | out: |
| 82 | return rc; |
| 83 | } |
| 84 | |
| 85 | /** |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 86 | * Header Extent: |
| 87 | * Octets 0-7: Unencrypted file size (big-endian) |
| 88 | * Octets 8-15: eCryptfs special marker |
| 89 | * Octets 16-19: Flags |
| 90 | * Octet 16: File format version number (between 0 and 255) |
| 91 | * Octets 17-18: Reserved |
| 92 | * Octet 19: Bit 1 (lsb): Reserved |
| 93 | * Bit 2: Encrypted? |
| 94 | * Bits 3-8: Reserved |
| 95 | * Octets 20-23: Header extent size (big-endian) |
| 96 | * Octets 24-25: Number of header extents at front of file |
| 97 | * (big-endian) |
| 98 | * Octet 26: Begin RFC 2440 authentication token packet set |
| 99 | */ |
| 100 | static void set_header_info(char *page_virt, |
| 101 | struct ecryptfs_crypt_stat *crypt_stat) |
| 102 | { |
| 103 | size_t written; |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 104 | size_t save_num_header_bytes_at_front = |
| 105 | crypt_stat->num_header_bytes_at_front; |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 106 | |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 107 | crypt_stat->num_header_bytes_at_front = |
| 108 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 109 | ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written); |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 110 | crypt_stat->num_header_bytes_at_front = |
| 111 | save_num_header_bytes_at_front; |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 112 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 113 | |
| 114 | /** |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 115 | * ecryptfs_copy_up_encrypted_with_header |
| 116 | * @page: Sort of a ``virtual'' representation of the encrypted lower |
| 117 | * file. The actual lower file does not have the metadata in |
| 118 | * the header. This is locked. |
| 119 | * @crypt_stat: The eCryptfs inode's cryptographic context |
| 120 | * |
| 121 | * The ``view'' is the version of the file that userspace winds up |
| 122 | * seeing, with the header information inserted. |
| 123 | */ |
| 124 | static int |
| 125 | ecryptfs_copy_up_encrypted_with_header(struct page *page, |
| 126 | struct ecryptfs_crypt_stat *crypt_stat) |
| 127 | { |
| 128 | loff_t extent_num_in_page = 0; |
| 129 | loff_t num_extents_per_page = (PAGE_CACHE_SIZE |
| 130 | / crypt_stat->extent_size); |
| 131 | int rc = 0; |
| 132 | |
| 133 | while (extent_num_in_page < num_extents_per_page) { |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 134 | loff_t view_extent_num = ((((loff_t)page->index) |
| 135 | * num_extents_per_page) |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 136 | + extent_num_in_page); |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 137 | size_t num_header_extents_at_front = |
| 138 | (crypt_stat->num_header_bytes_at_front |
| 139 | / crypt_stat->extent_size); |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 140 | |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 141 | if (view_extent_num < num_header_extents_at_front) { |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 142 | /* This is a header extent */ |
| 143 | char *page_virt; |
| 144 | |
| 145 | page_virt = kmap_atomic(page, KM_USER0); |
| 146 | memset(page_virt, 0, PAGE_CACHE_SIZE); |
| 147 | /* TODO: Support more than one header extent */ |
| 148 | if (view_extent_num == 0) { |
| 149 | rc = ecryptfs_read_xattr_region( |
| 150 | page_virt, page->mapping->host); |
| 151 | set_header_info(page_virt, crypt_stat); |
| 152 | } |
| 153 | kunmap_atomic(page_virt, KM_USER0); |
| 154 | flush_dcache_page(page); |
| 155 | if (rc) { |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 156 | printk(KERN_ERR "%s: Error reading xattr " |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 157 | "region; rc = [%d]\n", __func__, rc); |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 158 | goto out; |
| 159 | } |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 160 | } else { |
| 161 | /* This is an encrypted data extent */ |
| 162 | loff_t lower_offset = |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 163 | ((view_extent_num * crypt_stat->extent_size) |
| 164 | - crypt_stat->num_header_bytes_at_front); |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 165 | |
| 166 | rc = ecryptfs_read_lower_page_segment( |
| 167 | page, (lower_offset >> PAGE_CACHE_SHIFT), |
| 168 | (lower_offset & ~PAGE_CACHE_MASK), |
| 169 | crypt_stat->extent_size, page->mapping->host); |
| 170 | if (rc) { |
| 171 | printk(KERN_ERR "%s: Error attempting to read " |
| 172 | "extent at offset [%lld] in the lower " |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 173 | "file; rc = [%d]\n", __func__, |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 174 | lower_offset, rc); |
| 175 | goto out; |
| 176 | } |
| 177 | } |
| 178 | extent_num_in_page++; |
| 179 | } |
| 180 | out: |
| 181 | return rc; |
| 182 | } |
| 183 | |
| 184 | /** |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 185 | * ecryptfs_readpage |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 186 | * @file: An eCryptfs file |
| 187 | * @page: Page from eCryptfs inode mapping into which to stick the read data |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 188 | * |
| 189 | * Read in a page, decrypting if necessary. |
| 190 | * |
| 191 | * Returns zero on success; non-zero on error. |
| 192 | */ |
| 193 | static int ecryptfs_readpage(struct file *file, struct page *page) |
| 194 | { |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 195 | struct ecryptfs_crypt_stat *crypt_stat = |
| 196 | &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 197 | int rc = 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 198 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 199 | if (!crypt_stat |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 200 | || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED) |
| 201 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 202 | ecryptfs_printk(KERN_DEBUG, |
| 203 | "Passing through unencrypted page\n"); |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 204 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
| 205 | PAGE_CACHE_SIZE, |
| 206 | page->mapping->host); |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 207 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { |
| 208 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 209 | rc = ecryptfs_copy_up_encrypted_with_header(page, |
| 210 | crypt_stat); |
| 211 | if (rc) { |
| 212 | printk(KERN_ERR "%s: Error attempting to copy " |
| 213 | "the encrypted content from the lower " |
| 214 | "file whilst inserting the metadata " |
| 215 | "from the xattr into the header; rc = " |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 216 | "[%d]\n", __func__, rc); |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 217 | goto out; |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 218 | } |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 219 | |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 220 | } else { |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 221 | rc = ecryptfs_read_lower_page_segment( |
| 222 | page, page->index, 0, PAGE_CACHE_SIZE, |
| 223 | page->mapping->host); |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 224 | if (rc) { |
| 225 | printk(KERN_ERR "Error reading page; rc = " |
| 226 | "[%d]\n", rc); |
| 227 | goto out; |
| 228 | } |
| 229 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 230 | } else { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 231 | rc = ecryptfs_decrypt_page(page); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 232 | if (rc) { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 233 | ecryptfs_printk(KERN_ERR, "Error decrypting page; " |
| 234 | "rc = [%d]\n", rc); |
| 235 | goto out; |
| 236 | } |
| 237 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 238 | out: |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 239 | if (rc) |
| 240 | ClearPageUptodate(page); |
| 241 | else |
| 242 | SetPageUptodate(page); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 243 | ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n", |
| 244 | page->index); |
| 245 | unlock_page(page); |
| 246 | return rc; |
| 247 | } |
| 248 | |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 249 | /** |
| 250 | * Called with lower inode mutex held. |
| 251 | */ |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 252 | static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) |
| 253 | { |
| 254 | struct inode *inode = page->mapping->host; |
| 255 | int end_byte_in_page; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 256 | |
Michael Halcrow | 9d8b8ce | 2007-02-12 00:53:48 -0800 | [diff] [blame] | 257 | if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index) |
| 258 | goto out; |
| 259 | end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE; |
| 260 | if (to > end_byte_in_page) |
| 261 | end_byte_in_page = to; |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 262 | zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 263 | out: |
Michael Halcrow | 9d8b8ce | 2007-02-12 00:53:48 -0800 | [diff] [blame] | 264 | return 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 265 | } |
| 266 | |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 267 | /** |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 268 | * ecryptfs_write_begin |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 269 | * @file: The eCryptfs file |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 270 | * @mapping: The eCryptfs object |
| 271 | * @pos: The file offset at which to start writing |
| 272 | * @len: Length of the write |
| 273 | * @flags: Various flags |
| 274 | * @pagep: Pointer to return the page |
| 275 | * @fsdata: Pointer to return fs data (unused) |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 276 | * |
| 277 | * This function must zero any hole we create |
| 278 | * |
| 279 | * Returns zero on success; non-zero otherwise |
| 280 | */ |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 281 | static int ecryptfs_write_begin(struct file *file, |
| 282 | struct address_space *mapping, |
| 283 | loff_t pos, unsigned len, unsigned flags, |
| 284 | struct page **pagep, void **fsdata) |
Michael Halcrow | 53a2731 | 2007-05-23 13:58:15 -0700 | [diff] [blame] | 285 | { |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 286 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
| 287 | struct page *page; |
Eric Sandeen | 7a3f595 | 2007-12-17 16:20:10 -0800 | [diff] [blame] | 288 | loff_t prev_page_end_size; |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 289 | int rc = 0; |
Michael Halcrow | 53a2731 | 2007-05-23 13:58:15 -0700 | [diff] [blame] | 290 | |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 291 | page = __grab_cache_page(mapping, index); |
| 292 | if (!page) |
| 293 | return -ENOMEM; |
| 294 | *pagep = page; |
| 295 | |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 296 | if (!PageUptodate(page)) { |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 297 | struct ecryptfs_crypt_stat *crypt_stat = |
| 298 | &ecryptfs_inode_to_private( |
| 299 | file->f_path.dentry->d_inode)->crypt_stat; |
| 300 | |
| 301 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED) |
| 302 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { |
| 303 | rc = ecryptfs_read_lower_page_segment( |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 304 | page, index, 0, PAGE_CACHE_SIZE, mapping->host); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 305 | if (rc) { |
| 306 | printk(KERN_ERR "%s: Error attemping to read " |
| 307 | "lower page segment; rc = [%d]\n", |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 308 | __func__, rc); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 309 | ClearPageUptodate(page); |
| 310 | goto out; |
| 311 | } else |
| 312 | SetPageUptodate(page); |
| 313 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { |
| 314 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { |
| 315 | rc = ecryptfs_copy_up_encrypted_with_header( |
| 316 | page, crypt_stat); |
| 317 | if (rc) { |
| 318 | printk(KERN_ERR "%s: Error attempting " |
| 319 | "to copy the encrypted content " |
| 320 | "from the lower file whilst " |
| 321 | "inserting the metadata from " |
| 322 | "the xattr into the header; rc " |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 323 | "= [%d]\n", __func__, rc); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 324 | ClearPageUptodate(page); |
| 325 | goto out; |
| 326 | } |
| 327 | SetPageUptodate(page); |
| 328 | } else { |
| 329 | rc = ecryptfs_read_lower_page_segment( |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 330 | page, index, 0, PAGE_CACHE_SIZE, |
| 331 | mapping->host); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 332 | if (rc) { |
| 333 | printk(KERN_ERR "%s: Error reading " |
| 334 | "page; rc = [%d]\n", |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 335 | __func__, rc); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 336 | ClearPageUptodate(page); |
| 337 | goto out; |
| 338 | } |
| 339 | SetPageUptodate(page); |
| 340 | } |
| 341 | } else { |
| 342 | rc = ecryptfs_decrypt_page(page); |
| 343 | if (rc) { |
| 344 | printk(KERN_ERR "%s: Error decrypting page " |
| 345 | "at index [%ld]; rc = [%d]\n", |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 346 | __func__, page->index, rc); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 347 | ClearPageUptodate(page); |
| 348 | goto out; |
| 349 | } |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 350 | SetPageUptodate(page); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 351 | } |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 352 | } |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 353 | prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT); |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 354 | /* If creating a page or more of holes, zero them out via truncate. |
| 355 | * Note, this will increase i_size. */ |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 356 | if (index != 0) { |
Eric Sandeen | 7a3f595 | 2007-12-17 16:20:10 -0800 | [diff] [blame] | 357 | if (prev_page_end_size > i_size_read(page->mapping->host)) { |
Michael Halcrow | 240e2df | 2007-06-27 14:09:44 -0700 | [diff] [blame] | 358 | rc = ecryptfs_truncate(file->f_path.dentry, |
Eric Sandeen | 7a3f595 | 2007-12-17 16:20:10 -0800 | [diff] [blame] | 359 | prev_page_end_size); |
Michael Halcrow | 240e2df | 2007-06-27 14:09:44 -0700 | [diff] [blame] | 360 | if (rc) { |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 361 | printk(KERN_ERR "%s: Error on attempt to " |
Michael Halcrow | 240e2df | 2007-06-27 14:09:44 -0700 | [diff] [blame] | 362 | "truncate to (higher) offset [%lld];" |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 363 | " rc = [%d]\n", __func__, |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 364 | prev_page_end_size, rc); |
Michael Halcrow | 240e2df | 2007-06-27 14:09:44 -0700 | [diff] [blame] | 365 | goto out; |
| 366 | } |
Michael Halcrow | 53a2731 | 2007-05-23 13:58:15 -0700 | [diff] [blame] | 367 | } |
Eric Sandeen | 7a3f595 | 2007-12-17 16:20:10 -0800 | [diff] [blame] | 368 | } |
Michael Halcrow | e4465fd | 2008-03-04 14:29:24 -0800 | [diff] [blame] | 369 | /* Writing to a new page, and creating a small hole from start |
| 370 | * of page? Zero it out. */ |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 371 | if ((i_size_read(mapping->host) == prev_page_end_size) |
| 372 | && (pos != 0)) |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 373 | zero_user(page, 0, PAGE_CACHE_SIZE); |
Michael Halcrow | 53a2731 | 2007-05-23 13:58:15 -0700 | [diff] [blame] | 374 | out: |
| 375 | return rc; |
| 376 | } |
| 377 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 378 | /** |
| 379 | * ecryptfs_write_inode_size_to_header |
| 380 | * |
| 381 | * Writes the lower file size to the first 8 bytes of the header. |
| 382 | * |
| 383 | * Returns zero on success; non-zero on error. |
| 384 | */ |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 385 | static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 386 | { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 387 | char *file_size_virt; |
| 388 | int rc; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 389 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 390 | file_size_virt = kmalloc(sizeof(u64), GFP_KERNEL); |
| 391 | if (!file_size_virt) { |
| 392 | rc = -ENOMEM; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 393 | goto out; |
| 394 | } |
Harvey Harrison | 0a688ad | 2008-07-23 21:30:07 -0700 | [diff] [blame] | 395 | put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt); |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 396 | rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0, |
| 397 | sizeof(u64)); |
| 398 | kfree(file_size_virt); |
| 399 | if (rc) |
| 400 | printk(KERN_ERR "%s: Error writing file size to header; " |
Harvey Harrison | 18d1dbf | 2008-04-29 00:59:48 -0700 | [diff] [blame] | 401 | "rc = [%d]\n", __func__, rc); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 402 | out: |
| 403 | return rc; |
| 404 | } |
| 405 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 406 | struct kmem_cache *ecryptfs_xattr_cache; |
| 407 | |
| 408 | static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode) |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 409 | { |
| 410 | ssize_t size; |
| 411 | void *xattr_virt; |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 412 | struct dentry *lower_dentry = |
| 413 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; |
| 414 | struct inode *lower_inode = lower_dentry->d_inode; |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 415 | int rc; |
| 416 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 417 | if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) { |
| 418 | printk(KERN_WARNING |
| 419 | "No support for setting xattr in lower filesystem\n"); |
| 420 | rc = -ENOSYS; |
| 421 | goto out; |
| 422 | } |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 423 | xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL); |
| 424 | if (!xattr_virt) { |
| 425 | printk(KERN_ERR "Out of memory whilst attempting to write " |
| 426 | "inode size to xattr\n"); |
| 427 | rc = -ENOMEM; |
| 428 | goto out; |
| 429 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 430 | mutex_lock(&lower_inode->i_mutex); |
| 431 | size = lower_inode->i_op->getxattr(lower_dentry, ECRYPTFS_XATTR_NAME, |
| 432 | xattr_virt, PAGE_CACHE_SIZE); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 433 | if (size < 0) |
| 434 | size = 8; |
Harvey Harrison | 0a688ad | 2008-07-23 21:30:07 -0700 | [diff] [blame] | 435 | put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt); |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 436 | rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME, |
| 437 | xattr_virt, size, 0); |
| 438 | mutex_unlock(&lower_inode->i_mutex); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 439 | if (rc) |
| 440 | printk(KERN_ERR "Error whilst attempting to write inode size " |
| 441 | "to lower file xattr; rc = [%d]\n", rc); |
| 442 | kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); |
| 443 | out: |
| 444 | return rc; |
| 445 | } |
| 446 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 447 | int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode) |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 448 | { |
| 449 | struct ecryptfs_crypt_stat *crypt_stat; |
| 450 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 451 | crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 452 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 453 | return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 454 | else |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 455 | return ecryptfs_write_inode_size_to_header(ecryptfs_inode); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 456 | } |
| 457 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 458 | /** |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 459 | * ecryptfs_write_end |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 460 | * @file: The eCryptfs file object |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 461 | * @mapping: The eCryptfs object |
| 462 | * @pos: The file position |
| 463 | * @len: The length of the data (unused) |
| 464 | * @copied: The amount of data copied |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 465 | * @page: The eCryptfs page |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 466 | * @fsdata: The fsdata (unused) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 467 | * |
| 468 | * This is where we encrypt the data and pass the encrypted data to |
| 469 | * the lower filesystem. In OpenPGP-compatible mode, we operate on |
| 470 | * entire underlying packets. |
| 471 | */ |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 472 | static int ecryptfs_write_end(struct file *file, |
| 473 | struct address_space *mapping, |
| 474 | loff_t pos, unsigned len, unsigned copied, |
| 475 | struct page *page, void *fsdata) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 476 | { |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 477 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
| 478 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
| 479 | unsigned to = from + copied; |
| 480 | struct inode *ecryptfs_inode = mapping->host; |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 481 | struct ecryptfs_crypt_stat *crypt_stat = |
| 482 | &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 483 | int rc; |
| 484 | |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 485 | if (crypt_stat->flags & ECRYPTFS_NEW_FILE) { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 486 | ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in " |
| 487 | "crypt_stat at memory location [%p]\n", crypt_stat); |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 488 | crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 489 | } else |
| 490 | ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); |
| 491 | ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 492 | "(page w/ index = [0x%.16x], to = [%d])\n", index, to); |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 493 | /* Fills in zeros if 'to' goes beyond inode size */ |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 494 | rc = fill_zeros_to_end_of_page(page, to); |
| 495 | if (rc) { |
| 496 | ecryptfs_printk(KERN_WARNING, "Error attempting to fill " |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 497 | "zeros in page with index = [0x%.16x]\n", index); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 498 | goto out; |
| 499 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 500 | rc = ecryptfs_encrypt_page(page); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 501 | if (rc) { |
| 502 | ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper " |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 503 | "index [0x%.16x])\n", index); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 504 | goto out; |
| 505 | } |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 506 | if (pos + copied > i_size_read(ecryptfs_inode)) { |
| 507 | i_size_write(ecryptfs_inode, pos + copied); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 508 | ecryptfs_printk(KERN_DEBUG, "Expanded file size to " |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 509 | "[0x%.16x]\n", i_size_read(ecryptfs_inode)); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 510 | } |
Michael Halcrow | bf12be1 | 2007-10-16 01:28:11 -0700 | [diff] [blame] | 511 | rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 512 | if (rc) |
| 513 | printk(KERN_ERR "Error writing inode size to metadata; " |
| 514 | "rc = [%d]\n", rc); |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 515 | else |
| 516 | rc = copied; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 517 | out: |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 518 | unlock_page(page); |
| 519 | page_cache_release(page); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 520 | return rc; |
| 521 | } |
| 522 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 523 | static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block) |
| 524 | { |
| 525 | int rc = 0; |
| 526 | struct inode *inode; |
| 527 | struct inode *lower_inode; |
| 528 | |
| 529 | inode = (struct inode *)mapping->host; |
| 530 | lower_inode = ecryptfs_inode_to_lower(inode); |
| 531 | if (lower_inode->i_mapping->a_ops->bmap) |
| 532 | rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping, |
| 533 | block); |
| 534 | return rc; |
| 535 | } |
| 536 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 537 | struct address_space_operations ecryptfs_aops = { |
| 538 | .writepage = ecryptfs_writepage, |
| 539 | .readpage = ecryptfs_readpage, |
Badari Pulavarty | 807b7eb | 2008-10-15 22:02:50 -0700 | [diff] [blame] | 540 | .write_begin = ecryptfs_write_begin, |
| 541 | .write_end = ecryptfs_write_end, |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 542 | .bmap = ecryptfs_bmap, |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 543 | }; |