fs/hfsplus/xattr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/fs/hfsplus/xattr.c
   4  *
   5  * Vyacheslav Dubeyko <slava@dubeyko.com>
   6  *
   7  * Logic of processing extended attributes
   8  */
   9
  10 #include "hfsplus_fs.h"
  11 #include <linux/nls.h>
  12 #include "xattr.h"
  13
  14 static int hfsplus_removexattr(struct inode *inode, const char *name);
  15
  16 const struct xattr_handler *hfsplus_xattr_handlers[] = {
  17         &hfsplus_xattr_osx_handler,
  18         &hfsplus_xattr_user_handler,
  19         &hfsplus_xattr_trusted_handler,
  20         &hfsplus_xattr_security_handler,
  21         NULL
  22 };
  23
  24 static int strcmp_xattr_finder_info(const char *name)
  25 {
  26         if (name) {
  27                 return strncmp(name, HFSPLUS_XATTR_FINDER_INFO_NAME,
  28                                 sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME));
  29         }
  30         return -1;
  31 }
  32
  33 static int strcmp_xattr_acl(const char *name)
  34 {
  35         if (name) {
  36                 return strncmp(name, HFSPLUS_XATTR_ACL_NAME,
  37                                 sizeof(HFSPLUS_XATTR_ACL_NAME));
  38         }
  39         return -1;
  40 }
  41
  42 static bool is_known_namespace(const char *name)
  43 {
  44         if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
  45             strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
  46             strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
  47             strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
  48                 return false;
  49
  50         return true;
  51 }
  52
  53 static void hfsplus_init_header_node(struct inode *attr_file,
  54                                         u32 clump_size,
  55                                         char *buf, u16 node_size)
  56 {
  57         struct hfs_bnode_desc *desc;
  58         struct hfs_btree_header_rec *head;
  59         u16 offset;
  60         __be16 *rec_offsets;
  61         u32 hdr_node_map_rec_bits;
  62         char *bmp;
  63         u32 used_nodes;
  64         u32 used_bmp_bytes;
  65         u64 tmp;
  66
  67         hfs_dbg(ATTR_MOD, "init_hdr_attr_file: clump %u, node_size %u\n",
  68                 clump_size, node_size);
  69
  70         /* The end of the node contains list of record offsets */
  71         rec_offsets = (__be16 *)(buf + node_size);
  72
  73         desc = (struct hfs_bnode_desc *)buf;
  74         desc->type = HFS_NODE_HEADER;
  75         desc->num_recs = cpu_to_be16(HFSPLUS_BTREE_HDR_NODE_RECS_COUNT);
  76         offset = sizeof(struct hfs_bnode_desc);
  77         *--rec_offsets = cpu_to_be16(offset);
  78
  79         head = (struct hfs_btree_header_rec *)(buf + offset);
  80         head->node_size = cpu_to_be16(node_size);
  81         tmp = i_size_read(attr_file);
  82         do_div(tmp, node_size);
  83         head->node_count = cpu_to_be32(tmp);
  84         head->free_nodes = cpu_to_be32(be32_to_cpu(head->node_count) - 1);
  85         head->clump_size = cpu_to_be32(clump_size);
  86         head->attributes |= cpu_to_be32(HFS_TREE_BIGKEYS | HFS_TREE_VARIDXKEYS);
  87         head->max_key_len = cpu_to_be16(HFSPLUS_ATTR_KEYLEN - sizeof(u16));
  88         offset += sizeof(struct hfs_btree_header_rec);
  89         *--rec_offsets = cpu_to_be16(offset);
  90         offset += HFSPLUS_BTREE_HDR_USER_BYTES;
  91         *--rec_offsets = cpu_to_be16(offset);
  92
  93         hdr_node_map_rec_bits = 8 * (node_size - offset - (4 * sizeof(u16)));
  94         if (be32_to_cpu(head->node_count) > hdr_node_map_rec_bits) {
  95                 u32 map_node_bits;
  96                 u32 map_nodes;
  97
  98                 desc->next = cpu_to_be32(be32_to_cpu(head->leaf_tail) + 1);
  99                 map_node_bits = 8 * (node_size - sizeof(struct hfs_bnode_desc) -
 100                                         (2 * sizeof(u16)) - 2);
 101                 map_nodes = (be32_to_cpu(head->node_count) -
 102                                 hdr_node_map_rec_bits +
 103                                 (map_node_bits - 1)) / map_node_bits;
 104                 be32_add_cpu(&head->free_nodes, 0 - map_nodes);
 105         }
 106
 107         bmp = buf + offset;
 108         used_nodes =
 109                 be32_to_cpu(head->node_count) - be32_to_cpu(head->free_nodes);
 110         used_bmp_bytes = used_nodes / 8;
 111         if (used_bmp_bytes) {
 112                 memset(bmp, 0xFF, used_bmp_bytes);
 113                 bmp += used_bmp_bytes;
 114                 used_nodes %= 8;
 115         }
 116         *bmp = ~(0xFF >> used_nodes);
 117         offset += hdr_node_map_rec_bits / 8;
 118         *--rec_offsets = cpu_to_be16(offset);
 119 }
 120
 121 static int hfsplus_create_attributes_file(struct super_block *sb)
 122 {
 123         int err = 0;
 124         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 125         struct inode *attr_file;
 126         struct hfsplus_inode_info *hip;
 127         u32 clump_size;
 128         u16 node_size = HFSPLUS_ATTR_TREE_NODE_SIZE;
 129         char *buf;
 130         int index, written;
 131         struct address_space *mapping;
 132         struct page *page;
 133         int old_state = HFSPLUS_EMPTY_ATTR_TREE;
 134
 135         hfs_dbg(ATTR_MOD, "create_attr_file: ino %d\n", HFSPLUS_ATTR_CNID);
 136
 137 check_attr_tree_state_again:
 138         switch (atomic_read(&sbi->attr_tree_state)) {
 139         case HFSPLUS_EMPTY_ATTR_TREE:
 140                 if (old_state != atomic_cmpxchg(&sbi->attr_tree_state,
 141                                                 old_state,
 142                                                 HFSPLUS_CREATING_ATTR_TREE))
 143                         goto check_attr_tree_state_again;
 144                 break;
 145         case HFSPLUS_CREATING_ATTR_TREE:
 146                 /*
 147                  * This state means that another thread is in process
 148                  * of AttributesFile creation. Theoretically, it is
 149                  * possible to be here. But really __setxattr() method
 150                  * first of all calls hfs_find_init() for lookup in
 151                  * B-tree of CatalogFile. This method locks mutex of
 152                  * CatalogFile's B-tree. As a result, if some thread
 153                  * is inside AttributedFile creation operation then
 154                  * another threads will be waiting unlocking of
 155                  * CatalogFile's B-tree's mutex. However, if code will
 156                  * change then we will return error code (-EAGAIN) from
 157                  * here. Really, it means that first try to set of xattr
 158                  * fails with error but second attempt will have success.
 159                  */
 160                 return -EAGAIN;
 161         case HFSPLUS_VALID_ATTR_TREE:
 162                 return 0;
 163         case HFSPLUS_FAILED_ATTR_TREE:
 164                 return -EOPNOTSUPP;
 165         default:
 166                 BUG();
 167         }
 168
 169         attr_file = hfsplus_iget(sb, HFSPLUS_ATTR_CNID);
 170         if (IS_ERR(attr_file)) {
 171                 pr_err("failed to load attributes file\n");
 172                 return PTR_ERR(attr_file);
 173         }
 174
 175         BUG_ON(i_size_read(attr_file) != 0);
 176
 177         hip = HFSPLUS_I(attr_file);
 178
 179         clump_size = hfsplus_calc_btree_clump_size(sb->s_blocksize,
 180                                                     node_size,
 181                                                     sbi->sect_count,
 182                                                     HFSPLUS_ATTR_CNID);
 183
 184         mutex_lock(&hip->extents_lock);
 185         hip->clump_blocks = clump_size >> sbi->alloc_blksz_shift;
 186         mutex_unlock(&hip->extents_lock);
 187
 188         if (sbi->free_blocks <= (hip->clump_blocks << 1)) {
 189                 err = -ENOSPC;
 190                 goto end_attr_file_creation;
 191         }
 192
 193         while (hip->alloc_blocks < hip->clump_blocks) {
 194                 err = hfsplus_file_extend(attr_file, false);
 195                 if (unlikely(err)) {
 196                         pr_err("failed to extend attributes file\n");
 197                         goto end_attr_file_creation;
 198                 }
 199                 hip->phys_size = attr_file->i_size =
 200                         (loff_t)hip->alloc_blocks << sbi->alloc_blksz_shift;
 201                 hip->fs_blocks = hip->alloc_blocks << sbi->fs_shift;
 202                 inode_set_bytes(attr_file, attr_file->i_size);
 203         }
 204
 205         buf = kzalloc(node_size, GFP_NOFS);
 206         if (!buf) {
 207                 err = -ENOMEM;
 208                 goto end_attr_file_creation;
 209         }
 210
 211         hfsplus_init_header_node(attr_file, clump_size, buf, node_size);
 212
 213         mapping = attr_file->i_mapping;
 214
 215         index = 0;
 216         written = 0;
 217         for (; written < node_size; index++, written += PAGE_SIZE) {
 218                 void *kaddr;
 219
 220                 page = read_mapping_page(mapping, index, NULL);
 221                 if (IS_ERR(page)) {
 222                         err = PTR_ERR(page);
 223                         goto failed_header_node_init;
 224                 }
 225
 226                 kaddr = kmap_atomic(page);
 227                 memcpy(kaddr, buf + written,
 228                         min_t(size_t, PAGE_SIZE, node_size - written));
 229                 kunmap_atomic(kaddr);
 230
 231                 set_page_dirty(page);
 232                 put_page(page);
 233         }
 234
 235         hfsplus_mark_inode_dirty(attr_file, HFSPLUS_I_ATTR_DIRTY);
 236
 237         sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID);
 238         if (!sbi->attr_tree)
 239                 pr_err("failed to load attributes file\n");
 240
 241 failed_header_node_init:
 242         kfree(buf);
 243
 244 end_attr_file_creation:
 245         iput(attr_file);
 246
 247         if (!err)
 248                 atomic_set(&sbi->attr_tree_state, HFSPLUS_VALID_ATTR_TREE);
 249         else if (err == -ENOSPC)
 250                 atomic_set(&sbi->attr_tree_state, HFSPLUS_EMPTY_ATTR_TREE);
 251         else
 252                 atomic_set(&sbi->attr_tree_state, HFSPLUS_FAILED_ATTR_TREE);
 253
 254         return err;
 255 }
 256
 257 int __hfsplus_setxattr(struct inode *inode, const char *name,
 258                         const void *value, size_t size, int flags)
 259 {
 260         int err = 0;
 261         struct hfs_find_data cat_fd;
 262         hfsplus_cat_entry entry;
 263         u16 cat_entry_flags, cat_entry_type;
 264         u16 folder_finderinfo_len = sizeof(struct DInfo) +
 265                                         sizeof(struct DXInfo);
 266         u16 file_finderinfo_len = sizeof(struct FInfo) +
 267                                         sizeof(struct FXInfo);
 268
 269         if ((!S_ISREG(inode->i_mode) &&
 270                         !S_ISDIR(inode->i_mode)) ||
 271                                 HFSPLUS_IS_RSRC(inode))
 272                 return -EOPNOTSUPP;
 273
 274         if (value == NULL)
 275                 return hfsplus_removexattr(inode, name);
 276
 277         err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
 278         if (err) {
 279                 pr_err("can't init xattr find struct\n");
 280                 return err;
 281         }
 282
 283         err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
 284         if (err) {
 285                 pr_err("catalog searching failed\n");
 286                 goto end_setxattr;
 287         }
 288
 289         if (!strcmp_xattr_finder_info(name)) {
 290                 if (flags & XATTR_CREATE) {
 291                         pr_err("xattr exists yet\n");
 292                         err = -EOPNOTSUPP;
 293                         goto end_setxattr;
 294                 }
 295                 hfs_bnode_read(cat_fd.bnode, &entry, cat_fd.entryoffset,
 296                                         sizeof(hfsplus_cat_entry));
 297                 if (be16_to_cpu(entry.type) == HFSPLUS_FOLDER) {
 298                         if (size == folder_finderinfo_len) {
 299                                 memcpy(&entry.folder.user_info, value,
 300                                                 folder_finderinfo_len);
 301                                 hfs_bnode_write(cat_fd.bnode, &entry,
 302                                         cat_fd.entryoffset,
 303                                         sizeof(struct hfsplus_cat_folder));
 304                                 hfsplus_mark_inode_dirty(inode,
 305                                                 HFSPLUS_I_CAT_DIRTY);
 306                         } else {
 307                                 err = -ERANGE;
 308                                 goto end_setxattr;
 309                         }
 310                 } else if (be16_to_cpu(entry.type) == HFSPLUS_FILE) {
 311                         if (size == file_finderinfo_len) {
 312                                 memcpy(&entry.file.user_info, value,
 313                                                 file_finderinfo_len);
 314                                 hfs_bnode_write(cat_fd.bnode, &entry,
 315                                         cat_fd.entryoffset,
 316                                         sizeof(struct hfsplus_cat_file));
 317                                 hfsplus_mark_inode_dirty(inode,
 318                                                 HFSPLUS_I_CAT_DIRTY);
 319                         } else {
 320                                 err = -ERANGE;
 321                                 goto end_setxattr;
 322                         }
 323                 } else {
 324                         err = -EOPNOTSUPP;
 325                         goto end_setxattr;
 326                 }
 327                 goto end_setxattr;
 328         }
 329
 330         if (!HFSPLUS_SB(inode->i_sb)->attr_tree) {
 331                 err = hfsplus_create_attributes_file(inode->i_sb);
 332                 if (unlikely(err))
 333                         goto end_setxattr;
 334         }
 335
 336         if (hfsplus_attr_exists(inode, name)) {
 337                 if (flags & XATTR_CREATE) {
 338                         pr_err("xattr exists yet\n");
 339                         err = -EOPNOTSUPP;
 340                         goto end_setxattr;
 341                 }
 342                 err = hfsplus_delete_attr(inode, name);
 343                 if (err)
 344                         goto end_setxattr;
 345                 err = hfsplus_create_attr(inode, name, value, size);
 346                 if (err)
 347                         goto end_setxattr;
 348         } else {
 349                 if (flags & XATTR_REPLACE) {
 350                         pr_err("cannot replace xattr\n");
 351                         err = -EOPNOTSUPP;
 352                         goto end_setxattr;
 353                 }
 354                 err = hfsplus_create_attr(inode, name, value, size);
 355                 if (err)
 356                         goto end_setxattr;
 357         }
 358
 359         cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
 360         if (cat_entry_type == HFSPLUS_FOLDER) {
 361                 cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
 362                                     cat_fd.entryoffset +
 363                                     offsetof(struct hfsplus_cat_folder, flags));
 364                 cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
 365                 if (!strcmp_xattr_acl(name))
 366                         cat_entry_flags |= HFSPLUS_ACL_EXISTS;
 367                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 368                                 offsetof(struct hfsplus_cat_folder, flags),
 369                                 cat_entry_flags);
 370                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 371         } else if (cat_entry_type == HFSPLUS_FILE) {
 372                 cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
 373                                     cat_fd.entryoffset +
 374                                     offsetof(struct hfsplus_cat_file, flags));
 375                 cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
 376                 if (!strcmp_xattr_acl(name))
 377                         cat_entry_flags |= HFSPLUS_ACL_EXISTS;
 378                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 379                                     offsetof(struct hfsplus_cat_file, flags),
 380                                     cat_entry_flags);
 381                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 382         } else {
 383                 pr_err("invalid catalog entry type\n");
 384                 err = -EIO;
 385                 goto end_setxattr;
 386         }
 387
 388 end_setxattr:
 389         hfs_find_exit(&cat_fd);
 390         return err;
 391 }
 392
 393 static int name_len(const char *xattr_name, int xattr_name_len)
 394 {
 395         int len = xattr_name_len + 1;
 396
 397         if (!is_known_namespace(xattr_name))
 398                 len += XATTR_MAC_OSX_PREFIX_LEN;
 399
 400         return len;
 401 }
 402
 403 static int copy_name(char *buffer, const char *xattr_name, int name_len)
 404 {
 405         int len = name_len;
 406         int offset = 0;
 407
 408         if (!is_known_namespace(xattr_name)) {
 409                 memcpy(buffer, XATTR_MAC_OSX_PREFIX, XATTR_MAC_OSX_PREFIX_LEN);
 410                 offset += XATTR_MAC_OSX_PREFIX_LEN;
 411                 len += XATTR_MAC_OSX_PREFIX_LEN;
 412         }
 413
 414         strncpy(buffer + offset, xattr_name, name_len);
 415         memset(buffer + offset + name_len, 0, 1);
 416         len += 1;
 417
 418         return len;
 419 }
 420
 421 int hfsplus_setxattr(struct inode *inode, const char *name,
 422                      const void *value, size_t size, int flags,
 423                      const char *prefix, size_t prefixlen)
 424 {
 425         char *xattr_name;
 426         int res;
 427
 428         xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 429                 GFP_KERNEL);
 430         if (!xattr_name)
 431                 return -ENOMEM;
 432         strcpy(xattr_name, prefix);
 433         strcpy(xattr_name + prefixlen, name);
 434         res = __hfsplus_setxattr(inode, xattr_name, value, size, flags);
 435         kfree(xattr_name);
 436         return res;
 437 }
 438
 439 static ssize_t hfsplus_getxattr_finder_info(struct inode *inode,
 440                                                 void *value, size_t size)
 441 {
 442         ssize_t res = 0;
 443         struct hfs_find_data fd;
 444         u16 entry_type;
 445         u16 folder_rec_len = sizeof(struct DInfo) + sizeof(struct DXInfo);
 446         u16 file_rec_len = sizeof(struct FInfo) + sizeof(struct FXInfo);
 447         u16 record_len = max(folder_rec_len, file_rec_len);
 448         u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
 449         u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
 450
 451         if (size >= record_len) {
 452                 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
 453                 if (res) {
 454                         pr_err("can't init xattr find struct\n");
 455                         return res;
 456                 }
 457                 res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
 458                 if (res)
 459                         goto end_getxattr_finder_info;
 460                 entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
 461
 462                 if (entry_type == HFSPLUS_FOLDER) {
 463                         hfs_bnode_read(fd.bnode, folder_finder_info,
 464                                 fd.entryoffset +
 465                                 offsetof(struct hfsplus_cat_folder, user_info),
 466                                 folder_rec_len);
 467                         memcpy(value, folder_finder_info, folder_rec_len);
 468                         res = folder_rec_len;
 469                 } else if (entry_type == HFSPLUS_FILE) {
 470                         hfs_bnode_read(fd.bnode, file_finder_info,
 471                                 fd.entryoffset +
 472                                 offsetof(struct hfsplus_cat_file, user_info),
 473                                 file_rec_len);
 474                         memcpy(value, file_finder_info, file_rec_len);
 475                         res = file_rec_len;
 476                 } else {
 477                         res = -EOPNOTSUPP;
 478                         goto end_getxattr_finder_info;
 479                 }
 480         } else
 481                 res = size ? -ERANGE : record_len;
 482
 483 end_getxattr_finder_info:
 484         if (size >= record_len)
 485                 hfs_find_exit(&fd);
 486         return res;
 487 }
 488
 489 ssize_t __hfsplus_getxattr(struct inode *inode, const char *name,
 490                          void *value, size_t size)
 491 {
 492         struct hfs_find_data fd;
 493         hfsplus_attr_entry *entry;
 494         __be32 xattr_record_type;
 495         u32 record_type;
 496         u16 record_length = 0;
 497         ssize_t res = 0;
 498
 499         if ((!S_ISREG(inode->i_mode) &&
 500                         !S_ISDIR(inode->i_mode)) ||
 501                                 HFSPLUS_IS_RSRC(inode))
 502                 return -EOPNOTSUPP;
 503
 504         if (!strcmp_xattr_finder_info(name))
 505                 return hfsplus_getxattr_finder_info(inode, value, size);
 506
 507         if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
 508                 return -EOPNOTSUPP;
 509
 510         entry = hfsplus_alloc_attr_entry();
 511         if (!entry) {
 512                 pr_err("can't allocate xattr entry\n");
 513                 return -ENOMEM;
 514         }
 515
 516         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
 517         if (res) {
 518                 pr_err("can't init xattr find struct\n");
 519                 goto failed_getxattr_init;
 520         }
 521
 522         res = hfsplus_find_attr(inode->i_sb, inode->i_ino, name, &fd);
 523         if (res) {
 524                 if (res == -ENOENT)
 525                         res = -ENODATA;
 526                 else
 527                         pr_err("xattr searching failed\n");
 528                 goto out;
 529         }
 530
 531         hfs_bnode_read(fd.bnode, &xattr_record_type,
 532                         fd.entryoffset, sizeof(xattr_record_type));
 533         record_type = be32_to_cpu(xattr_record_type);
 534         if (record_type == HFSPLUS_ATTR_INLINE_DATA) {
 535                 record_length = hfs_bnode_read_u16(fd.bnode,
 536                                 fd.entryoffset +
 537                                 offsetof(struct hfsplus_attr_inline_data,
 538                                 length));
 539                 if (record_length > HFSPLUS_MAX_INLINE_DATA_SIZE) {
 540                         pr_err("invalid xattr record size\n");
 541                         res = -EIO;
 542                         goto out;
 543                 }
 544         } else if (record_type == HFSPLUS_ATTR_FORK_DATA ||
 545                         record_type == HFSPLUS_ATTR_EXTENTS) {
 546                 pr_err("only inline data xattr are supported\n");
 547                 res = -EOPNOTSUPP;
 548                 goto out;
 549         } else {
 550                 pr_err("invalid xattr record\n");
 551                 res = -EIO;
 552                 goto out;
 553         }
 554
 555         if (size) {
 556                 hfs_bnode_read(fd.bnode, entry, fd.entryoffset,
 557                                 offsetof(struct hfsplus_attr_inline_data,
 558                                         raw_bytes) + record_length);
 559         }
 560
 561         if (size >= record_length) {
 562                 memcpy(value, entry->inline_data.raw_bytes, record_length);
 563                 res = record_length;
 564         } else
 565                 res = size ? -ERANGE : record_length;
 566
 567 out:
 568         hfs_find_exit(&fd);
 569
 570 failed_getxattr_init:
 571         hfsplus_destroy_attr_entry(entry);
 572         return res;
 573 }
 574
 575 ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
 576                          void *value, size_t size,
 577                          const char *prefix, size_t prefixlen)
 578 {
 579         int res;
 580         char *xattr_name;
 581
 582         xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 583                              GFP_KERNEL);
 584         if (!xattr_name)
 585                 return -ENOMEM;
 586
 587         strcpy(xattr_name, prefix);
 588         strcpy(xattr_name + prefixlen, name);
 589
 590         res = __hfsplus_getxattr(inode, xattr_name, value, size);
 591         kfree(xattr_name);
 592         return res;
 593
 594 }
 595
 596 static inline int can_list(const char *xattr_name)
 597 {
 598         if (!xattr_name)
 599                 return 0;
 600
 601         return strncmp(xattr_name, XATTR_TRUSTED_PREFIX,
 602                         XATTR_TRUSTED_PREFIX_LEN) ||
 603                                 capable(CAP_SYS_ADMIN);
 604 }
 605
 606 static ssize_t hfsplus_listxattr_finder_info(struct dentry *dentry,
 607                                                 char *buffer, size_t size)
 608 {
 609         ssize_t res = 0;
 610         struct inode *inode = d_inode(dentry);
 611         struct hfs_find_data fd;
 612         u16 entry_type;
 613         u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
 614         u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
 615         unsigned long len, found_bit;
 616         int xattr_name_len, symbols_count;
 617
 618         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
 619         if (res) {
 620                 pr_err("can't init xattr find struct\n");
 621                 return res;
 622         }
 623
 624         res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
 625         if (res)
 626                 goto end_listxattr_finder_info;
 627
 628         entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
 629         if (entry_type == HFSPLUS_FOLDER) {
 630                 len = sizeof(struct DInfo) + sizeof(struct DXInfo);
 631                 hfs_bnode_read(fd.bnode, folder_finder_info,
 632                                 fd.entryoffset +
 633                                 offsetof(struct hfsplus_cat_folder, user_info),
 634                                 len);
 635                 found_bit = find_first_bit((void *)folder_finder_info, len*8);
 636         } else if (entry_type == HFSPLUS_FILE) {
 637                 len = sizeof(struct FInfo) + sizeof(struct FXInfo);
 638                 hfs_bnode_read(fd.bnode, file_finder_info,
 639                                 fd.entryoffset +
 640                                 offsetof(struct hfsplus_cat_file, user_info),
 641                                 len);
 642                 found_bit = find_first_bit((void *)file_finder_info, len*8);
 643         } else {
 644                 res = -EOPNOTSUPP;
 645                 goto end_listxattr_finder_info;
 646         }
 647
 648         if (found_bit >= (len*8))
 649                 res = 0;
 650         else {
 651                 symbols_count = sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME) - 1;
 652                 xattr_name_len =
 653                         name_len(HFSPLUS_XATTR_FINDER_INFO_NAME, symbols_count);
 654                 if (!buffer || !size) {
 655                         if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME))
 656                                 res = xattr_name_len;
 657                 } else if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME)) {
 658                         if (size < xattr_name_len)
 659                                 res = -ERANGE;
 660                         else {
 661                                 res = copy_name(buffer,
 662                                                 HFSPLUS_XATTR_FINDER_INFO_NAME,
 663                                                 symbols_count);
 664                         }
 665                 }
 666         }
 667
 668 end_listxattr_finder_info:
 669         hfs_find_exit(&fd);
 670
 671         return res;
 672 }
 673
 674 ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
 675 {
 676         ssize_t err;
 677         ssize_t res = 0;
 678         struct inode *inode = d_inode(dentry);
 679         struct hfs_find_data fd;
 680         u16 key_len = 0;
 681         struct hfsplus_attr_key attr_key;
 682         char *strbuf;
 683         int xattr_name_len;
 684
 685         if ((!S_ISREG(inode->i_mode) &&
 686                         !S_ISDIR(inode->i_mode)) ||
 687                                 HFSPLUS_IS_RSRC(inode))
 688                 return -EOPNOTSUPP;
 689
 690         res = hfsplus_listxattr_finder_info(dentry, buffer, size);
 691         if (res < 0)
 692                 return res;
 693         else if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
 694                 return (res == 0) ? -EOPNOTSUPP : res;
 695
 696         err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
 697         if (err) {
 698                 pr_err("can't init xattr find struct\n");
 699                 return err;
 700         }
 701
 702         strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
 703                         XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
 704         if (!strbuf) {
 705                 res = -ENOMEM;
 706                 goto out;
 707         }
 708
 709         err = hfsplus_find_attr(inode->i_sb, inode->i_ino, NULL, &fd);
 710         if (err) {
 711                 if (err == -ENOENT) {
 712                         if (res == 0)
 713                                 res = -ENODATA;
 714                         goto end_listxattr;
 715                 } else {
 716                         res = err;
 717                         goto end_listxattr;
 718                 }
 719         }
 720
 721         for (;;) {
 722                 key_len = hfs_bnode_read_u16(fd.bnode, fd.keyoffset);
 723                 if (key_len == 0 || key_len > fd.tree->max_key_len) {
 724                         pr_err("invalid xattr key length: %d\n", key_len);
 725                         res = -EIO;
 726                         goto end_listxattr;
 727                 }
 728
 729                 hfs_bnode_read(fd.bnode, &attr_key,
 730                                 fd.keyoffset, key_len + sizeof(key_len));
 731
 732                 if (be32_to_cpu(attr_key.cnid) != inode->i_ino)
 733                         goto end_listxattr;
 734
 735                 xattr_name_len = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN;
 736                 if (hfsplus_uni2asc(inode->i_sb,
 737                         (const struct hfsplus_unistr *)&fd.key->attr.key_name,
 738                                         strbuf, &xattr_name_len)) {
 739                         pr_err("unicode conversion failed\n");
 740                         res = -EIO;
 741                         goto end_listxattr;
 742                 }
 743
 744                 if (!buffer || !size) {
 745                         if (can_list(strbuf))
 746                                 res += name_len(strbuf, xattr_name_len);
 747                 } else if (can_list(strbuf)) {
 748                         if (size < (res + name_len(strbuf, xattr_name_len))) {
 749                                 res = -ERANGE;
 750                                 goto end_listxattr;
 751                         } else
 752                                 res += copy_name(buffer + res,
 753                                                 strbuf, xattr_name_len);
 754                 }
 755
 756                 if (hfs_brec_goto(&fd, 1))
 757                         goto end_listxattr;
 758         }
 759
 760 end_listxattr:
 761         kfree(strbuf);
 762 out:
 763         hfs_find_exit(&fd);
 764         return res;
 765 }
 766
 767 static int hfsplus_removexattr(struct inode *inode, const char *name)
 768 {
 769         int err = 0;
 770         struct hfs_find_data cat_fd;
 771         u16 flags;
 772         u16 cat_entry_type;
 773         int is_xattr_acl_deleted = 0;
 774         int is_all_xattrs_deleted = 0;
 775
 776         if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
 777                 return -EOPNOTSUPP;
 778
 779         if (!strcmp_xattr_finder_info(name))
 780                 return -EOPNOTSUPP;
 781
 782         err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
 783         if (err) {
 784                 pr_err("can't init xattr find struct\n");
 785                 return err;
 786         }
 787
 788         err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
 789         if (err) {
 790                 pr_err("catalog searching failed\n");
 791                 goto end_removexattr;
 792         }
 793
 794         err = hfsplus_delete_attr(inode, name);
 795         if (err)
 796                 goto end_removexattr;
 797
 798         is_xattr_acl_deleted = !strcmp_xattr_acl(name);
 799         is_all_xattrs_deleted = !hfsplus_attr_exists(inode, NULL);
 800
 801         if (!is_xattr_acl_deleted && !is_all_xattrs_deleted)
 802                 goto end_removexattr;
 803
 804         cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
 805
 806         if (cat_entry_type == HFSPLUS_FOLDER) {
 807                 flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
 808                                 offsetof(struct hfsplus_cat_folder, flags));
 809                 if (is_xattr_acl_deleted)
 810                         flags &= ~HFSPLUS_ACL_EXISTS;
 811                 if (is_all_xattrs_deleted)
 812                         flags &= ~HFSPLUS_XATTR_EXISTS;
 813                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 814                                 offsetof(struct hfsplus_cat_folder, flags),
 815                                 flags);
 816                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 817         } else if (cat_entry_type == HFSPLUS_FILE) {
 818                 flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
 819                                 offsetof(struct hfsplus_cat_file, flags));
 820                 if (is_xattr_acl_deleted)
 821                         flags &= ~HFSPLUS_ACL_EXISTS;
 822                 if (is_all_xattrs_deleted)
 823                         flags &= ~HFSPLUS_XATTR_EXISTS;
 824                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 825                                 offsetof(struct hfsplus_cat_file, flags),
 826                                 flags);
 827                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 828         } else {
 829                 pr_err("invalid catalog entry type\n");
 830                 err = -EIO;
 831                 goto end_removexattr;
 832         }
 833
 834 end_removexattr:
 835         hfs_find_exit(&cat_fd);
 836         return err;
 837 }
 838
 839 static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
 840                                 struct dentry *unused, struct inode *inode,
 841                                 const char *name, void *buffer, size_t size)
 842 {
 843         /*
 844          * Don't allow retrieving properly prefixed attributes
 845          * by prepending them with "osx."
 846          */
 847         if (is_known_namespace(name))
 848                 return -EOPNOTSUPP;
 849
 850         /*
 851          * osx is the namespace we use to indicate an unprefixed
 852          * attribute on the filesystem (like the ones that OS X
 853          * creates), so we pass the name through unmodified (after
 854          * ensuring it doesn't conflict with another namespace).
 855          */
 856         return __hfsplus_getxattr(inode, name, buffer, size);
 857 }
 858
 859 static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
 860                                 struct user_namespace *mnt_userns,
 861                                 struct dentry *unused, struct inode *inode,
 862                                 const char *name, const void *buffer,
 863                                 size_t size, int flags)
 864 {
 865         /*
 866          * Don't allow setting properly prefixed attributes
 867          * by prepending them with "osx."
 868          */
 869         if (is_known_namespace(name))
 870                 return -EOPNOTSUPP;
 871
 872         /*
 873          * osx is the namespace we use to indicate an unprefixed
 874          * attribute on the filesystem (like the ones that OS X
 875          * creates), so we pass the name through unmodified (after
 876          * ensuring it doesn't conflict with another namespace).
 877          */
 878         return __hfsplus_setxattr(inode, name, buffer, size, flags);
 879 }
 880
 881 const struct xattr_handler hfsplus_xattr_osx_handler = {
 882         .prefix = XATTR_MAC_OSX_PREFIX,
 883         .get    = hfsplus_osx_getxattr,
 884         .set    = hfsplus_osx_setxattr,
 885 };