1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * 4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved. 5 * 6 */ 7 8 #include <linux/fs.h> 9 10 #include "debug.h" 11 #include "ntfs.h" 12 #include "ntfs_fs.h" 13 14 static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type, 15 const __le16 *name, u8 name_len, 16 const u16 *upcase) 17 { 18 /* First, compare the type codes. */ 19 int diff = le32_to_cpu(left->type) - le32_to_cpu(type); 20 21 if (diff) 22 return diff; 23 24 /* They have the same type code, so we have to compare the names. */ 25 return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len, 26 upcase, true); 27 } 28 29 /* 30 * mi_new_attt_id 31 * 32 * Return: Unused attribute id that is less than mrec->next_attr_id. 33 */ 34 static __le16 mi_new_attt_id(struct mft_inode *mi) 35 { 36 u16 free_id, max_id, t16; 37 struct MFT_REC *rec = mi->mrec; 38 struct ATTRIB *attr; 39 __le16 id; 40 41 id = rec->next_attr_id; 42 free_id = le16_to_cpu(id); 43 if (free_id < 0x7FFF) { 44 rec->next_attr_id = cpu_to_le16(free_id + 1); 45 return id; 46 } 47 48 /* One record can store up to 1024/24 ~= 42 attributes. */ 49 free_id = 0; 50 max_id = 0; 51 52 attr = NULL; 53 54 for (;;) { 55 attr = mi_enum_attr(mi, attr); 56 if (!attr) { 57 rec->next_attr_id = cpu_to_le16(max_id + 1); 58 mi->dirty = true; 59 return cpu_to_le16(free_id); 60 } 61 62 t16 = le16_to_cpu(attr->id); 63 if (t16 == free_id) { 64 free_id += 1; 65 attr = NULL; 66 } else if (max_id < t16) 67 max_id = t16; 68 } 69 } 70 71 int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi) 72 { 73 int err; 74 struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS); 75 76 if (!m) 77 return -ENOMEM; 78 79 err = mi_init(m, sbi, rno); 80 if (err) { 81 kfree(m); 82 return err; 83 } 84 85 err = mi_read(m, false); 86 if (err) { 87 mi_put(m); 88 return err; 89 } 90 91 *mi = m; 92 return 0; 93 } 94 95 void mi_put(struct mft_inode *mi) 96 { 97 mi_clear(mi); 98 kfree(mi); 99 } 100 101 int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno) 102 { 103 mi->sbi = sbi; 104 mi->rno = rno; 105 mi->mrec = kmalloc(sbi->record_size, GFP_NOFS); 106 if (!mi->mrec) 107 return -ENOMEM; 108 109 return 0; 110 } 111 112 /* 113 * mi_read - Read MFT data. 114 */ 115 int mi_read(struct mft_inode *mi, bool is_mft) 116 { 117 int err; 118 struct MFT_REC *rec = mi->mrec; 119 struct ntfs_sb_info *sbi = mi->sbi; 120 u32 bpr = sbi->record_size; 121 u64 vbo = (u64)mi->rno << sbi->record_bits; 122 struct ntfs_inode *mft_ni = sbi->mft.ni; 123 struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL; 124 struct rw_semaphore *rw_lock = NULL; 125 126 if (is_mounted(sbi)) { 127 if (!is_mft && mft_ni) { 128 rw_lock = &mft_ni->file.run_lock; 129 down_read(rw_lock); 130 } 131 } 132 133 err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb); 134 if (rw_lock) 135 up_read(rw_lock); 136 if (!err) 137 goto ok; 138 139 if (err == -E_NTFS_FIXUP) { 140 mi->dirty = true; 141 goto ok; 142 } 143 144 if (err != -ENOENT) 145 goto out; 146 147 if (rw_lock) { 148 ni_lock(mft_ni); 149 down_write(rw_lock); 150 } 151 err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, run, 152 vbo >> sbi->cluster_bits); 153 if (rw_lock) { 154 up_write(rw_lock); 155 ni_unlock(mft_ni); 156 } 157 if (err) 158 goto out; 159 160 if (rw_lock) 161 down_read(rw_lock); 162 err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb); 163 if (rw_lock) 164 up_read(rw_lock); 165 166 if (err == -E_NTFS_FIXUP) { 167 mi->dirty = true; 168 goto ok; 169 } 170 if (err) 171 goto out; 172 173 ok: 174 /* Check field 'total' only here. */ 175 if (le32_to_cpu(rec->total) != bpr) { 176 err = -EINVAL; 177 goto out; 178 } 179 180 return 0; 181 182 out: 183 if (err == -E_NTFS_CORRUPT) { 184 ntfs_err(sbi->sb, "mft corrupted"); 185 ntfs_set_state(sbi, NTFS_DIRTY_ERROR); 186 err = -EINVAL; 187 } 188 189 return err; 190 } 191 192 /* 193 * mi_enum_attr - start/continue attributes enumeration in record. 194 * 195 * NOTE: mi->mrec - memory of size sbi->record_size 196 * here we sure that mi->mrec->total == sbi->record_size (see mi_read) 197 */ 198 struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr) 199 { 200 const struct MFT_REC *rec = mi->mrec; 201 u32 used = le32_to_cpu(rec->used); 202 u32 t32, off, asize, prev_type; 203 u16 t16; 204 u64 data_size, alloc_size, tot_size; 205 206 if (!attr) { 207 u32 total = le32_to_cpu(rec->total); 208 209 off = le16_to_cpu(rec->attr_off); 210 211 if (used > total) 212 return NULL; 213 214 if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 || 215 !IS_ALIGNED(off, 4)) { 216 return NULL; 217 } 218 219 /* Skip non-resident records. */ 220 if (!is_rec_inuse(rec)) 221 return NULL; 222 223 prev_type = 0; 224 attr = Add2Ptr(rec, off); 225 } else { 226 /* Check if input attr inside record. */ 227 off = PtrOffset(rec, attr); 228 if (off >= used) 229 return NULL; 230 231 asize = le32_to_cpu(attr->size); 232 if (asize < SIZEOF_RESIDENT) { 233 /* Impossible 'cause we should not return such attribute. */ 234 return NULL; 235 } 236 237 /* Overflow check. */ 238 if (off + asize < off) 239 return NULL; 240 241 prev_type = le32_to_cpu(attr->type); 242 attr = Add2Ptr(attr, asize); 243 off += asize; 244 } 245 246 asize = le32_to_cpu(attr->size); 247 248 /* Can we use the first field (attr->type). */ 249 if (off + 8 > used) { 250 static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8); 251 return NULL; 252 } 253 254 if (attr->type == ATTR_END) { 255 /* End of enumeration. */ 256 return NULL; 257 } 258 259 /* 0x100 is last known attribute for now. */ 260 t32 = le32_to_cpu(attr->type); 261 if (!t32 || (t32 & 0xf) || (t32 > 0x100)) 262 return NULL; 263 264 /* attributes in record must be ordered by type */ 265 if (t32 < prev_type) 266 return NULL; 267 268 /* Check overflow and boundary. */ 269 if (off + asize < off || off + asize > used) 270 return NULL; 271 272 /* Check size of attribute. */ 273 if (!attr->non_res) { 274 /* Check resident fields. */ 275 if (asize < SIZEOF_RESIDENT) 276 return NULL; 277 278 t16 = le16_to_cpu(attr->res.data_off); 279 if (t16 > asize) 280 return NULL; 281 282 if (le32_to_cpu(attr->res.data_size) > asize - t16) 283 return NULL; 284 285 t32 = sizeof(short) * attr->name_len; 286 if (t32 && le16_to_cpu(attr->name_off) + t32 > t16) 287 return NULL; 288 289 return attr; 290 } 291 292 /* Check nonresident fields. */ 293 if (attr->non_res != 1) 294 return NULL; 295 296 t16 = le16_to_cpu(attr->nres.run_off); 297 if (t16 > asize) 298 return NULL; 299 300 t32 = sizeof(short) * attr->name_len; 301 if (t32 && le16_to_cpu(attr->name_off) + t32 > t16) 302 return NULL; 303 304 /* Check start/end vcn. */ 305 if (le64_to_cpu(attr->nres.svcn) > le64_to_cpu(attr->nres.evcn) + 1) 306 return NULL; 307 308 data_size = le64_to_cpu(attr->nres.data_size); 309 if (le64_to_cpu(attr->nres.valid_size) > data_size) 310 return NULL; 311 312 alloc_size = le64_to_cpu(attr->nres.alloc_size); 313 if (data_size > alloc_size) 314 return NULL; 315 316 t32 = mi->sbi->cluster_mask; 317 if (alloc_size & t32) 318 return NULL; 319 320 if (!attr->nres.svcn && is_attr_ext(attr)) { 321 /* First segment of sparse/compressed attribute */ 322 if (asize + 8 < SIZEOF_NONRESIDENT_EX) 323 return NULL; 324 325 tot_size = le64_to_cpu(attr->nres.total_size); 326 if (tot_size & t32) 327 return NULL; 328 329 if (tot_size > alloc_size) 330 return NULL; 331 } else { 332 if (asize + 8 < SIZEOF_NONRESIDENT) 333 return NULL; 334 335 if (attr->nres.c_unit) 336 return NULL; 337 } 338 339 return attr; 340 } 341 342 /* 343 * mi_find_attr - Find the attribute by type and name and id. 344 */ 345 struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr, 346 enum ATTR_TYPE type, const __le16 *name, 347 u8 name_len, const __le16 *id) 348 { 349 u32 type_in = le32_to_cpu(type); 350 u32 atype; 351 352 next_attr: 353 attr = mi_enum_attr(mi, attr); 354 if (!attr) 355 return NULL; 356 357 atype = le32_to_cpu(attr->type); 358 if (atype > type_in) 359 return NULL; 360 361 if (atype < type_in) 362 goto next_attr; 363 364 if (attr->name_len != name_len) 365 goto next_attr; 366 367 if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short))) 368 goto next_attr; 369 370 if (id && *id != attr->id) 371 goto next_attr; 372 373 return attr; 374 } 375 376 int mi_write(struct mft_inode *mi, int wait) 377 { 378 struct MFT_REC *rec; 379 int err; 380 struct ntfs_sb_info *sbi; 381 382 if (!mi->dirty) 383 return 0; 384 385 sbi = mi->sbi; 386 rec = mi->mrec; 387 388 err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait); 389 if (err) 390 return err; 391 392 if (mi->rno < sbi->mft.recs_mirr) 393 sbi->flags |= NTFS_FLAGS_MFTMIRR; 394 395 mi->dirty = false; 396 397 return 0; 398 } 399 400 int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno, 401 __le16 flags, bool is_mft) 402 { 403 int err; 404 u16 seq = 1; 405 struct MFT_REC *rec; 406 u64 vbo = (u64)rno << sbi->record_bits; 407 408 err = mi_init(mi, sbi, rno); 409 if (err) 410 return err; 411 412 rec = mi->mrec; 413 414 if (rno == MFT_REC_MFT) { 415 ; 416 } else if (rno < MFT_REC_FREE) { 417 seq = rno; 418 } else if (rno >= sbi->mft.used) { 419 ; 420 } else if (mi_read(mi, is_mft)) { 421 ; 422 } else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) { 423 /* Record is reused. Update its sequence number. */ 424 seq = le16_to_cpu(rec->seq) + 1; 425 if (!seq) 426 seq = 1; 427 } 428 429 memcpy(rec, sbi->new_rec, sbi->record_size); 430 431 rec->seq = cpu_to_le16(seq); 432 rec->flags = RECORD_FLAG_IN_USE | flags; 433 if (MFTRECORD_FIXUP_OFFSET == MFTRECORD_FIXUP_OFFSET_3) 434 rec->mft_record = cpu_to_le32(rno); 435 436 mi->dirty = true; 437 438 if (!mi->nb.nbufs) { 439 struct ntfs_inode *ni = sbi->mft.ni; 440 bool lock = false; 441 442 if (is_mounted(sbi) && !is_mft) { 443 down_read(&ni->file.run_lock); 444 lock = true; 445 } 446 447 err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size, 448 &mi->nb); 449 if (lock) 450 up_read(&ni->file.run_lock); 451 } 452 453 return err; 454 } 455 456 /* 457 * mi_insert_attr - Reserve space for new attribute. 458 * 459 * Return: Not full constructed attribute or NULL if not possible to create. 460 */ 461 struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type, 462 const __le16 *name, u8 name_len, u32 asize, 463 u16 name_off) 464 { 465 size_t tail; 466 struct ATTRIB *attr; 467 __le16 id; 468 struct MFT_REC *rec = mi->mrec; 469 struct ntfs_sb_info *sbi = mi->sbi; 470 u32 used = le32_to_cpu(rec->used); 471 const u16 *upcase = sbi->upcase; 472 473 /* Can we insert mi attribute? */ 474 if (used + asize > sbi->record_size) 475 return NULL; 476 477 /* 478 * Scan through the list of attributes to find the point 479 * at which we should insert it. 480 */ 481 attr = NULL; 482 while ((attr = mi_enum_attr(mi, attr))) { 483 int diff = compare_attr(attr, type, name, name_len, upcase); 484 485 if (diff < 0) 486 continue; 487 488 if (!diff && !is_attr_indexed(attr)) 489 return NULL; 490 break; 491 } 492 493 if (!attr) { 494 /* Append. */ 495 tail = 8; 496 attr = Add2Ptr(rec, used - 8); 497 } else { 498 /* Insert before 'attr'. */ 499 tail = used - PtrOffset(rec, attr); 500 } 501 502 id = mi_new_attt_id(mi); 503 504 memmove(Add2Ptr(attr, asize), attr, tail); 505 memset(attr, 0, asize); 506 507 attr->type = type; 508 attr->size = cpu_to_le32(asize); 509 attr->name_len = name_len; 510 attr->name_off = cpu_to_le16(name_off); 511 attr->id = id; 512 513 memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short)); 514 rec->used = cpu_to_le32(used + asize); 515 516 mi->dirty = true; 517 518 return attr; 519 } 520 521 /* 522 * mi_remove_attr - Remove the attribute from record. 523 * 524 * NOTE: The source attr will point to next attribute. 525 */ 526 bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi, 527 struct ATTRIB *attr) 528 { 529 struct MFT_REC *rec = mi->mrec; 530 u32 aoff = PtrOffset(rec, attr); 531 u32 used = le32_to_cpu(rec->used); 532 u32 asize = le32_to_cpu(attr->size); 533 534 if (aoff + asize > used) 535 return false; 536 537 if (ni && is_attr_indexed(attr)) { 538 u16 links = le16_to_cpu(ni->mi.mrec->hard_links); 539 struct ATTR_FILE_NAME *fname = 540 attr->type != ATTR_NAME ? 541 NULL : 542 resident_data_ex(attr, 543 SIZEOF_ATTRIBUTE_FILENAME); 544 if (fname && fname->type == FILE_NAME_DOS) { 545 /* Do not decrease links count deleting DOS name. */ 546 } else if (!links) { 547 /* minor error. Not critical. */ 548 } else { 549 ni->mi.mrec->hard_links = cpu_to_le16(links - 1); 550 ni->mi.dirty = true; 551 } 552 } 553 554 used -= asize; 555 memmove(attr, Add2Ptr(attr, asize), used - aoff); 556 rec->used = cpu_to_le32(used); 557 mi->dirty = true; 558 559 return true; 560 } 561 562 /* bytes = "new attribute size" - "old attribute size" */ 563 bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes) 564 { 565 struct MFT_REC *rec = mi->mrec; 566 u32 aoff = PtrOffset(rec, attr); 567 u32 total, used = le32_to_cpu(rec->used); 568 u32 nsize, asize = le32_to_cpu(attr->size); 569 u32 rsize = le32_to_cpu(attr->res.data_size); 570 int tail = (int)(used - aoff - asize); 571 int dsize; 572 char *next; 573 574 if (tail < 0 || aoff >= used) 575 return false; 576 577 if (!bytes) 578 return true; 579 580 total = le32_to_cpu(rec->total); 581 next = Add2Ptr(attr, asize); 582 583 if (bytes > 0) { 584 dsize = ALIGN(bytes, 8); 585 if (used + dsize > total) 586 return false; 587 nsize = asize + dsize; 588 /* Move tail */ 589 memmove(next + dsize, next, tail); 590 memset(next, 0, dsize); 591 used += dsize; 592 rsize += dsize; 593 } else { 594 dsize = ALIGN(-bytes, 8); 595 if (dsize > asize) 596 return false; 597 nsize = asize - dsize; 598 memmove(next - dsize, next, tail); 599 used -= dsize; 600 rsize -= dsize; 601 } 602 603 rec->used = cpu_to_le32(used); 604 attr->size = cpu_to_le32(nsize); 605 if (!attr->non_res) 606 attr->res.data_size = cpu_to_le32(rsize); 607 mi->dirty = true; 608 609 return true; 610 } 611 612 /* 613 * Pack runs in MFT record. 614 * If failed record is not changed. 615 */ 616 int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr, 617 struct runs_tree *run, CLST len) 618 { 619 int err = 0; 620 struct ntfs_sb_info *sbi = mi->sbi; 621 u32 new_run_size; 622 CLST plen; 623 struct MFT_REC *rec = mi->mrec; 624 CLST svcn = le64_to_cpu(attr->nres.svcn); 625 u32 used = le32_to_cpu(rec->used); 626 u32 aoff = PtrOffset(rec, attr); 627 u32 asize = le32_to_cpu(attr->size); 628 char *next = Add2Ptr(attr, asize); 629 u16 run_off = le16_to_cpu(attr->nres.run_off); 630 u32 run_size = asize - run_off; 631 u32 tail = used - aoff - asize; 632 u32 dsize = sbi->record_size - used; 633 634 /* Make a maximum gap in current record. */ 635 memmove(next + dsize, next, tail); 636 637 /* Pack as much as possible. */ 638 err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize, 639 &plen); 640 if (err < 0) { 641 memmove(next, next + dsize, tail); 642 return err; 643 } 644 645 new_run_size = ALIGN(err, 8); 646 647 memmove(next + new_run_size - run_size, next + dsize, tail); 648 649 attr->size = cpu_to_le32(asize + new_run_size - run_size); 650 attr->nres.evcn = cpu_to_le64(svcn + plen - 1); 651 rec->used = cpu_to_le32(used + new_run_size - run_size); 652 mi->dirty = true; 653 654 return 0; 655 } 656