1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * 4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved. 5 * 6 * Directory handling functions for NTFS-based filesystems. 7 * 8 */ 9 10 #include <linux/fs.h> 11 #include <linux/filelock.h> 12 #include <linux/nls.h> 13 14 #include "debug.h" 15 #include "ntfs.h" 16 #include "ntfs_fs.h" 17 18 /* Convert little endian UTF-16 to NLS string. */ 19 int ntfs_utf16_to_nls(struct ntfs_sb_info *sbi, const __le16 *name, u32 len, 20 u8 *buf, int buf_len) 21 { 22 int ret, warn; 23 u8 *op; 24 struct nls_table *nls = sbi->options->nls; 25 26 static_assert(sizeof(wchar_t) == sizeof(__le16)); 27 28 if (!nls) { 29 /* UTF-16 -> UTF-8 */ 30 ret = utf16s_to_utf8s((wchar_t *)name, len, UTF16_LITTLE_ENDIAN, 31 buf, buf_len); 32 buf[ret] = '\0'; 33 return ret; 34 } 35 36 op = buf; 37 warn = 0; 38 39 while (len--) { 40 u16 ec; 41 int charlen; 42 char dump[5]; 43 44 if (buf_len < NLS_MAX_CHARSET_SIZE) { 45 ntfs_warn(sbi->sb, 46 "filename was truncated while converting."); 47 break; 48 } 49 50 ec = le16_to_cpu(*name++); 51 charlen = nls->uni2char(ec, op, buf_len); 52 53 if (charlen > 0) { 54 op += charlen; 55 buf_len -= charlen; 56 continue; 57 } 58 59 *op++ = '_'; 60 buf_len -= 1; 61 if (warn) 62 continue; 63 64 warn = 1; 65 hex_byte_pack(&dump[0], ec >> 8); 66 hex_byte_pack(&dump[2], ec); 67 dump[4] = 0; 68 69 ntfs_err(sbi->sb, "failed to convert \"%s\" to %s", dump, 70 nls->charset); 71 } 72 73 *op = '\0'; 74 return op - buf; 75 } 76 77 // clang-format off 78 #define PLANE_SIZE 0x00010000 79 80 #define SURROGATE_PAIR 0x0000d800 81 #define SURROGATE_LOW 0x00000400 82 #define SURROGATE_BITS 0x000003ff 83 // clang-format on 84 85 /* 86 * put_utf16 - Modified version of put_utf16 from fs/nls/nls_base.c 87 * 88 * Function is sparse warnings free. 89 */ 90 static inline void put_utf16(wchar_t *s, unsigned int c, 91 enum utf16_endian endian) 92 { 93 static_assert(sizeof(wchar_t) == sizeof(__le16)); 94 static_assert(sizeof(wchar_t) == sizeof(__be16)); 95 96 switch (endian) { 97 default: 98 *s = (wchar_t)c; 99 break; 100 case UTF16_LITTLE_ENDIAN: 101 *(__le16 *)s = __cpu_to_le16(c); 102 break; 103 case UTF16_BIG_ENDIAN: 104 *(__be16 *)s = __cpu_to_be16(c); 105 break; 106 } 107 } 108 109 /* 110 * _utf8s_to_utf16s 111 * 112 * Modified version of 'utf8s_to_utf16s' allows to 113 * detect -ENAMETOOLONG without writing out of expected maximum. 114 */ 115 static int _utf8s_to_utf16s(const u8 *s, int inlen, enum utf16_endian endian, 116 wchar_t *pwcs, int maxout) 117 { 118 u16 *op; 119 int size; 120 unicode_t u; 121 122 op = pwcs; 123 while (inlen > 0 && *s) { 124 if (*s & 0x80) { 125 size = utf8_to_utf32(s, inlen, &u); 126 if (size < 0) 127 return -EINVAL; 128 s += size; 129 inlen -= size; 130 131 if (u >= PLANE_SIZE) { 132 if (maxout < 2) 133 return -ENAMETOOLONG; 134 135 u -= PLANE_SIZE; 136 put_utf16(op++, 137 SURROGATE_PAIR | 138 ((u >> 10) & SURROGATE_BITS), 139 endian); 140 put_utf16(op++, 141 SURROGATE_PAIR | SURROGATE_LOW | 142 (u & SURROGATE_BITS), 143 endian); 144 maxout -= 2; 145 } else { 146 if (maxout < 1) 147 return -ENAMETOOLONG; 148 149 put_utf16(op++, u, endian); 150 maxout--; 151 } 152 } else { 153 if (maxout < 1) 154 return -ENAMETOOLONG; 155 156 put_utf16(op++, *s++, endian); 157 inlen--; 158 maxout--; 159 } 160 } 161 return op - pwcs; 162 } 163 164 /* 165 * ntfs_nls_to_utf16 - Convert input string to UTF-16. 166 * @name: Input name. 167 * @name_len: Input name length. 168 * @uni: Destination memory. 169 * @max_ulen: Destination memory. 170 * @endian: Endian of target UTF-16 string. 171 * 172 * This function is called: 173 * - to create NTFS name 174 * - to create symlink 175 * 176 * Return: UTF-16 string length or error (if negative). 177 */ 178 int ntfs_nls_to_utf16(struct ntfs_sb_info *sbi, const u8 *name, u32 name_len, 179 struct cpu_str *uni, u32 max_ulen, 180 enum utf16_endian endian) 181 { 182 int ret, slen; 183 const u8 *end; 184 struct nls_table *nls = sbi->options->nls; 185 u16 *uname = uni->name; 186 187 static_assert(sizeof(wchar_t) == sizeof(u16)); 188 189 if (!nls) { 190 /* utf8 -> utf16 */ 191 ret = _utf8s_to_utf16s(name, name_len, endian, uname, max_ulen); 192 uni->len = ret; 193 return ret; 194 } 195 196 for (ret = 0, end = name + name_len; name < end; ret++, name += slen) { 197 if (ret >= max_ulen) 198 return -ENAMETOOLONG; 199 200 slen = nls->char2uni(name, end - name, uname + ret); 201 if (!slen) 202 return -EINVAL; 203 if (slen < 0) 204 return slen; 205 } 206 207 #ifdef __BIG_ENDIAN 208 if (endian == UTF16_LITTLE_ENDIAN) { 209 int i = ret; 210 211 while (i--) { 212 __cpu_to_le16s(uname); 213 uname++; 214 } 215 } 216 #else 217 if (endian == UTF16_BIG_ENDIAN) { 218 int i = ret; 219 220 while (i--) { 221 __cpu_to_be16s(uname); 222 uname++; 223 } 224 } 225 #endif 226 227 uni->len = ret; 228 return ret; 229 } 230 231 /* 232 * dir_search_u - Helper function. 233 */ 234 struct inode *dir_search_u(struct inode *dir, const struct cpu_str *uni, 235 struct ntfs_fnd *fnd) 236 { 237 int err = 0; 238 struct super_block *sb = dir->i_sb; 239 struct ntfs_sb_info *sbi = sb->s_fs_info; 240 struct ntfs_inode *ni = ntfs_i(dir); 241 struct NTFS_DE *e; 242 int diff; 243 struct inode *inode = NULL; 244 struct ntfs_fnd *fnd_a = NULL; 245 246 if (!fnd) { 247 fnd_a = fnd_get(); 248 if (!fnd_a) { 249 err = -ENOMEM; 250 goto out; 251 } 252 fnd = fnd_a; 253 } 254 255 err = indx_find(&ni->dir, ni, NULL, uni, 0, sbi, &diff, &e, fnd); 256 257 if (err) 258 goto out; 259 260 if (diff) { 261 err = -ENOENT; 262 goto out; 263 } 264 265 inode = ntfs_iget5(sb, &e->ref, uni); 266 if (!IS_ERR(inode) && is_bad_inode(inode)) { 267 iput(inode); 268 err = -EINVAL; 269 } 270 out: 271 fnd_put(fnd_a); 272 273 return err == -ENOENT ? NULL : err ? ERR_PTR(err) : inode; 274 } 275 276 /* 277 * returns false if 'ctx' if full 278 */ 279 static inline bool ntfs_dir_emit(struct ntfs_sb_info *sbi, 280 struct ntfs_inode *ni, const struct NTFS_DE *e, 281 u8 *name, struct dir_context *ctx) 282 { 283 const struct ATTR_FILE_NAME *fname; 284 unsigned long ino; 285 int name_len; 286 u32 dt_type; 287 288 fname = Add2Ptr(e, sizeof(struct NTFS_DE)); 289 290 if (fname->type == FILE_NAME_DOS) 291 return true; 292 293 if (!mi_is_ref(&ni->mi, &fname->home)) 294 return true; 295 296 ino = ino_get(&e->ref); 297 298 if (ino == MFT_REC_ROOT) 299 return true; 300 301 /* Skip meta files. Unless option to show metafiles is set. */ 302 if (!sbi->options->showmeta && ntfs_is_meta_file(sbi, ino)) 303 return true; 304 305 if (sbi->options->nohidden && (fname->dup.fa & FILE_ATTRIBUTE_HIDDEN)) 306 return true; 307 308 if (fname->name_len + sizeof(struct NTFS_DE) > le16_to_cpu(e->size)) 309 return true; 310 311 name_len = ntfs_utf16_to_nls(sbi, fname->name, fname->name_len, name, 312 PATH_MAX); 313 if (name_len <= 0) { 314 ntfs_warn(sbi->sb, "failed to convert name for inode %lx.", 315 ino); 316 return true; 317 } 318 319 /* 320 * NTFS: symlinks are "dir + reparse" or "file + reparse" 321 * Unfortunately reparse attribute is used for many purposes (several dozens). 322 * It is not possible here to know is this name symlink or not. 323 * To get exactly the type of name we should to open inode (read mft). 324 * getattr for opened file (fstat) correctly returns symlink. 325 */ 326 dt_type = (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) ? DT_DIR : DT_REG; 327 328 /* 329 * It is not reliable to detect the type of name using duplicated information 330 * stored in parent directory. 331 * The only correct way to get the type of name - read MFT record and find ATTR_STD. 332 * The code below is not good idea. 333 * It does additional locks/reads just to get the type of name. 334 * Should we use additional mount option to enable branch below? 335 */ 336 if (fname->dup.extend_data && ino != ni->mi.rno) { 337 struct inode *inode = ntfs_iget5(sbi->sb, &e->ref, NULL); 338 if (!IS_ERR_OR_NULL(inode)) { 339 dt_type = fs_umode_to_dtype(inode->i_mode); 340 iput(inode); 341 } 342 } 343 344 return dir_emit(ctx, (s8 *)name, name_len, ino, dt_type); 345 } 346 347 /* 348 * ntfs_read_hdr - Helper function for ntfs_readdir(). 349 * 350 * returns 0 if ok. 351 * returns -EINVAL if directory is corrupted. 352 * returns +1 if 'ctx' is full. 353 */ 354 static int ntfs_read_hdr(struct ntfs_sb_info *sbi, struct ntfs_inode *ni, 355 const struct INDEX_HDR *hdr, u64 vbo, u64 pos, 356 u8 *name, struct dir_context *ctx) 357 { 358 const struct NTFS_DE *e; 359 u32 e_size; 360 u32 end = le32_to_cpu(hdr->used); 361 u32 off = le32_to_cpu(hdr->de_off); 362 363 for (;; off += e_size) { 364 if (off + sizeof(struct NTFS_DE) > end) 365 return -EINVAL; 366 367 e = Add2Ptr(hdr, off); 368 e_size = le16_to_cpu(e->size); 369 if (e_size < sizeof(struct NTFS_DE) || off + e_size > end) 370 return -EINVAL; 371 372 if (de_is_last(e)) 373 return 0; 374 375 /* Skip already enumerated. */ 376 if (vbo + off < pos) 377 continue; 378 379 if (le16_to_cpu(e->key_size) < SIZEOF_ATTRIBUTE_FILENAME) 380 return -EINVAL; 381 382 ctx->pos = vbo + off; 383 384 /* Submit the name to the filldir callback. */ 385 if (!ntfs_dir_emit(sbi, ni, e, name, ctx)) { 386 /* ctx is full. */ 387 return +1; 388 } 389 } 390 } 391 392 /* 393 * ntfs_readdir - file_operations::iterate_shared 394 * 395 * Use non sorted enumeration. 396 * We have an example of broken volume where sorted enumeration 397 * counts each name twice. 398 */ 399 static int ntfs_readdir(struct file *file, struct dir_context *ctx) 400 { 401 const struct INDEX_ROOT *root; 402 u64 vbo; 403 size_t bit; 404 loff_t eod; 405 int err = 0; 406 struct inode *dir = file_inode(file); 407 struct ntfs_inode *ni = ntfs_i(dir); 408 struct super_block *sb = dir->i_sb; 409 struct ntfs_sb_info *sbi = sb->s_fs_info; 410 loff_t i_size = i_size_read(dir); 411 u32 pos = ctx->pos; 412 u8 *name = NULL; 413 struct indx_node *node = NULL; 414 u8 index_bits = ni->dir.index_bits; 415 416 /* Name is a buffer of PATH_MAX length. */ 417 static_assert(NTFS_NAME_LEN * 4 < PATH_MAX); 418 419 eod = i_size + sbi->record_size; 420 421 if (pos >= eod) 422 return 0; 423 424 if (!dir_emit_dots(file, ctx)) 425 return 0; 426 427 name = kmalloc(PATH_MAX, GFP_KERNEL); 428 if (!name) 429 return -ENOMEM; 430 431 if (!ni->mi_loaded && ni->attr_list.size) { 432 /* 433 * Directory inode is locked for read. 434 * Load all subrecords to avoid 'write' access to 'ni' during 435 * directory reading. 436 */ 437 ni_lock(ni); 438 if (!ni->mi_loaded && ni->attr_list.size) { 439 err = ni_load_all_mi(ni); 440 if (!err) 441 ni->mi_loaded = true; 442 } 443 ni_unlock(ni); 444 if (err) 445 goto out; 446 } 447 448 root = indx_get_root(&ni->dir, ni, NULL, NULL); 449 if (!root) { 450 err = -EINVAL; 451 goto out; 452 } 453 454 if (pos >= sbi->record_size) { 455 bit = (pos - sbi->record_size) >> index_bits; 456 } else { 457 err = ntfs_read_hdr(sbi, ni, &root->ihdr, 0, pos, name, ctx); 458 if (err) 459 goto out; 460 bit = 0; 461 } 462 463 if (!i_size) { 464 ctx->pos = eod; 465 goto out; 466 } 467 468 for (;;) { 469 vbo = (u64)bit << index_bits; 470 if (vbo >= i_size) { 471 ctx->pos = eod; 472 goto out; 473 } 474 475 err = indx_used_bit(&ni->dir, ni, &bit); 476 if (err) 477 goto out; 478 479 if (bit == MINUS_ONE_T) { 480 ctx->pos = eod; 481 goto out; 482 } 483 484 vbo = (u64)bit << index_bits; 485 if (vbo >= i_size) { 486 err = -EINVAL; 487 goto out; 488 } 489 490 err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits, 491 &node); 492 if (err) 493 goto out; 494 495 err = ntfs_read_hdr(sbi, ni, &node->index->ihdr, 496 vbo + sbi->record_size, pos, name, ctx); 497 if (err) 498 goto out; 499 500 bit += 1; 501 } 502 503 out: 504 505 kfree(name); 506 put_indx_node(node); 507 508 if (err == 1) { 509 /* 'ctx' is full. */ 510 err = 0; 511 } else if (err == -ENOENT) { 512 err = 0; 513 ctx->pos = pos; 514 } else if (err < 0) { 515 if (err == -EINVAL) 516 _ntfs_bad_inode(dir); 517 ctx->pos = eod; 518 } 519 520 return err; 521 } 522 523 static int ntfs_dir_count(struct inode *dir, bool *is_empty, size_t *dirs, 524 size_t *files) 525 { 526 int err = 0; 527 struct ntfs_inode *ni = ntfs_i(dir); 528 struct NTFS_DE *e = NULL; 529 struct INDEX_ROOT *root; 530 struct INDEX_HDR *hdr; 531 const struct ATTR_FILE_NAME *fname; 532 u32 e_size, off, end; 533 size_t drs = 0, fles = 0, bit = 0; 534 struct indx_node *node = NULL; 535 size_t max_indx = i_size_read(&ni->vfs_inode) >> ni->dir.index_bits; 536 537 if (is_empty) 538 *is_empty = true; 539 540 root = indx_get_root(&ni->dir, ni, NULL, NULL); 541 if (!root) 542 return -EINVAL; 543 544 hdr = &root->ihdr; 545 546 for (;;) { 547 end = le32_to_cpu(hdr->used); 548 off = le32_to_cpu(hdr->de_off); 549 550 for (; off + sizeof(struct NTFS_DE) <= end; off += e_size) { 551 e = Add2Ptr(hdr, off); 552 e_size = le16_to_cpu(e->size); 553 if (e_size < sizeof(struct NTFS_DE) || 554 off + e_size > end) { 555 /* Looks like corruption. */ 556 break; 557 } 558 559 if (de_is_last(e)) 560 break; 561 562 fname = de_get_fname(e); 563 if (!fname) 564 continue; 565 566 if (fname->type == FILE_NAME_DOS) 567 continue; 568 569 if (is_empty) { 570 *is_empty = false; 571 if (!dirs && !files) 572 goto out; 573 } 574 575 if (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) 576 drs += 1; 577 else 578 fles += 1; 579 } 580 581 if (bit >= max_indx) 582 goto out; 583 584 err = indx_used_bit(&ni->dir, ni, &bit); 585 if (err) 586 goto out; 587 588 if (bit == MINUS_ONE_T) 589 goto out; 590 591 if (bit >= max_indx) 592 goto out; 593 594 err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits, 595 &node); 596 if (err) 597 goto out; 598 599 hdr = &node->index->ihdr; 600 bit += 1; 601 } 602 603 out: 604 put_indx_node(node); 605 if (dirs) 606 *dirs = drs; 607 if (files) 608 *files = fles; 609 610 return err; 611 } 612 613 bool dir_is_empty(struct inode *dir) 614 { 615 bool is_empty = false; 616 617 ntfs_dir_count(dir, &is_empty, NULL, NULL); 618 619 return is_empty; 620 } 621 622 // clang-format off 623 const struct file_operations ntfs_dir_operations = { 624 .llseek = generic_file_llseek, 625 .read = generic_read_dir, 626 .iterate_shared = ntfs_readdir, 627 .fsync = generic_file_fsync, 628 .open = ntfs_file_open, 629 .unlocked_ioctl = ntfs_ioctl, 630 #ifdef CONFIG_COMPAT 631 .compat_ioctl = ntfs_compat_ioctl, 632 #endif 633 .setlease = generic_setlease, 634 }; 635 636 #if IS_ENABLED(CONFIG_NTFS_FS) 637 const struct file_operations ntfs_legacy_dir_operations = { 638 .llseek = generic_file_llseek, 639 .read = generic_read_dir, 640 .iterate_shared = ntfs_readdir, 641 .open = ntfs_file_open, 642 .setlease = generic_setlease, 643 }; 644 #endif 645 // clang-format on 646