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