archive_read_support_filter_lz4.c revision 305188
1/*- 2 * Copyright (c) 2014 Michihiro NAKAJIMA 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "archive_platform.h" 27 28__FBSDID("$FreeBSD: stable/11/contrib/libarchive/libarchive/archive_read_support_filter_lz4.c 305188 2016-09-01 07:53:59Z mm $"); 29 30#ifdef HAVE_ERRNO_H 31#include <errno.h> 32#endif 33#include <stdio.h> 34#ifdef HAVE_STDLIB_H 35#include <stdlib.h> 36#endif 37#ifdef HAVE_STRING_H 38#include <string.h> 39#endif 40#ifdef HAVE_UNISTD_H 41#include <unistd.h> 42#endif 43#ifdef HAVE_LZ4_H 44#include <lz4.h> 45#endif 46 47#include "archive.h" 48#include "archive_endian.h" 49#include "archive_private.h" 50#include "archive_read_private.h" 51#include "archive_xxhash.h" 52 53#define LZ4_MAGICNUMBER 0x184d2204 54#define LZ4_SKIPPABLED 0x184d2a50 55#define LZ4_LEGACY 0x184c2102 56 57#if defined(HAVE_LIBLZ4) 58struct private_data { 59 enum { SELECT_STREAM, 60 READ_DEFAULT_STREAM, 61 READ_DEFAULT_BLOCK, 62 READ_LEGACY_STREAM, 63 READ_LEGACY_BLOCK, 64 } stage; 65 struct { 66 unsigned block_independence:1; 67 unsigned block_checksum:3; 68 unsigned stream_size:1; 69 unsigned stream_checksum:1; 70 unsigned preset_dictionary:1; 71 int block_maximum_size; 72 } flags; 73 int64_t stream_size; 74 uint32_t dict_id; 75 char *out_block; 76 size_t out_block_size; 77 78 /* Bytes read but not yet consumed via __archive_read_consume() */ 79 size_t unconsumed; 80 size_t decoded_size; 81 void *xxh32_state; 82 83 char valid; /* True = decompressor is initialized */ 84 char eof; /* True = found end of compressed data. */ 85}; 86 87#define LEGACY_BLOCK_SIZE (8 * 1024 * 1024) 88 89/* Lz4 filter */ 90static ssize_t lz4_filter_read(struct archive_read_filter *, const void **); 91static int lz4_filter_close(struct archive_read_filter *); 92#endif 93 94/* 95 * Note that we can detect lz4 archives even if we can't decompress 96 * them. (In fact, we like detecting them because we can give better 97 * error messages.) So the bid framework here gets compiled even 98 * if liblz4 is unavailable. 99 */ 100static int lz4_reader_bid(struct archive_read_filter_bidder *, struct archive_read_filter *); 101static int lz4_reader_init(struct archive_read_filter *); 102static int lz4_reader_free(struct archive_read_filter_bidder *); 103#if defined(HAVE_LIBLZ4) 104static ssize_t lz4_filter_read_default_stream(struct archive_read_filter *, 105 const void **); 106static ssize_t lz4_filter_read_legacy_stream(struct archive_read_filter *, 107 const void **); 108#endif 109 110int 111archive_read_support_filter_lz4(struct archive *_a) 112{ 113 struct archive_read *a = (struct archive_read *)_a; 114 struct archive_read_filter_bidder *reader; 115 116 archive_check_magic(_a, ARCHIVE_READ_MAGIC, 117 ARCHIVE_STATE_NEW, "archive_read_support_filter_lz4"); 118 119 if (__archive_read_get_bidder(a, &reader) != ARCHIVE_OK) 120 return (ARCHIVE_FATAL); 121 122 reader->data = NULL; 123 reader->name = "lz4"; 124 reader->bid = lz4_reader_bid; 125 reader->init = lz4_reader_init; 126 reader->options = NULL; 127 reader->free = lz4_reader_free; 128#if defined(HAVE_LIBLZ4) 129 return (ARCHIVE_OK); 130#else 131 archive_set_error(_a, ARCHIVE_ERRNO_MISC, 132 "Using external lz4 program"); 133 return (ARCHIVE_WARN); 134#endif 135} 136 137static int 138lz4_reader_free(struct archive_read_filter_bidder *self){ 139 (void)self; /* UNUSED */ 140 return (ARCHIVE_OK); 141} 142 143/* 144 * Test whether we can handle this data. 145 * 146 * This logic returns zero if any part of the signature fails. It 147 * also tries to Do The Right Thing if a very short buffer prevents us 148 * from verifying as much as we would like. 149 */ 150static int 151lz4_reader_bid(struct archive_read_filter_bidder *self, 152 struct archive_read_filter *filter) 153{ 154 const unsigned char *buffer; 155 ssize_t avail; 156 int bits_checked; 157 uint32_t number; 158 159 (void)self; /* UNUSED */ 160 161 /* Minimal lz4 archive is 11 bytes. */ 162 buffer = __archive_read_filter_ahead(filter, 11, &avail); 163 if (buffer == NULL) 164 return (0); 165 166 /* First four bytes must be LZ4 magic numbers. */ 167 bits_checked = 0; 168 if ((number = archive_le32dec(buffer)) == LZ4_MAGICNUMBER) { 169 unsigned char flag, BD; 170 171 bits_checked += 32; 172 /* Next follows a stream descriptor. */ 173 /* Descriptor Flags. */ 174 flag = buffer[4]; 175 /* A version number must be "01". */ 176 if (((flag & 0xc0) >> 6) != 1) 177 return (0); 178 /* A reserved bit must be "0". */ 179 if (flag & 2) 180 return (0); 181 bits_checked += 8; 182 BD = buffer[5]; 183 /* A block maximum size shuld be more than 3. */ 184 if (((BD & 0x70) >> 4) < 4) 185 return (0); 186 /* Reserved bits must be "0". */ 187 if (BD & ~0x70) 188 return (0); 189 bits_checked += 8; 190 } else if (number == LZ4_LEGACY) { 191 bits_checked += 32; 192 } 193 194 return (bits_checked); 195} 196 197#if !defined(HAVE_LIBLZ4) 198 199/* 200 * If we don't have the library on this system, we can't actually do the 201 * decompression. We can, however, still detect compressed archives 202 * and emit a useful message. 203 */ 204static int 205lz4_reader_init(struct archive_read_filter *self) 206{ 207 int r; 208 209 r = __archive_read_program(self, "lz4 -d -q"); 210 /* Note: We set the format here even if __archive_read_program() 211 * above fails. We do, after all, know what the format is 212 * even if we weren't able to read it. */ 213 self->code = ARCHIVE_FILTER_LZ4; 214 self->name = "lz4"; 215 return (r); 216} 217 218 219#else 220 221/* 222 * Setup the callbacks. 223 */ 224static int 225lz4_reader_init(struct archive_read_filter *self) 226{ 227 struct private_data *state; 228 229 self->code = ARCHIVE_FILTER_LZ4; 230 self->name = "lz4"; 231 232 state = (struct private_data *)calloc(sizeof(*state), 1); 233 if (state == NULL) { 234 archive_set_error(&self->archive->archive, ENOMEM, 235 "Can't allocate data for lz4 decompression"); 236 return (ARCHIVE_FATAL); 237 } 238 239 self->data = state; 240 state->stage = SELECT_STREAM; 241 self->read = lz4_filter_read; 242 self->skip = NULL; /* not supported */ 243 self->close = lz4_filter_close; 244 245 return (ARCHIVE_OK); 246} 247 248static int 249lz4_allocate_out_block(struct archive_read_filter *self) 250{ 251 struct private_data *state = (struct private_data *)self->data; 252 size_t out_block_size = state->flags.block_maximum_size; 253 void *out_block; 254 255 if (!state->flags.block_independence) 256 out_block_size += 64 * 1024; 257 if (state->out_block_size < out_block_size) { 258 free(state->out_block); 259 out_block = (unsigned char *)malloc(out_block_size); 260 state->out_block_size = out_block_size; 261 if (out_block == NULL) { 262 archive_set_error(&self->archive->archive, ENOMEM, 263 "Can't allocate data for lz4 decompression"); 264 return (ARCHIVE_FATAL); 265 } 266 state->out_block = out_block; 267 } 268 if (!state->flags.block_independence) 269 memset(state->out_block, 0, 64 * 1024); 270 return (ARCHIVE_OK); 271} 272 273static int 274lz4_allocate_out_block_for_legacy(struct archive_read_filter *self) 275{ 276 struct private_data *state = (struct private_data *)self->data; 277 size_t out_block_size = LEGACY_BLOCK_SIZE; 278 void *out_block; 279 280 if (state->out_block_size < out_block_size) { 281 free(state->out_block); 282 out_block = (unsigned char *)malloc(out_block_size); 283 state->out_block_size = out_block_size; 284 if (out_block == NULL) { 285 archive_set_error(&self->archive->archive, ENOMEM, 286 "Can't allocate data for lz4 decompression"); 287 return (ARCHIVE_FATAL); 288 } 289 state->out_block = out_block; 290 } 291 return (ARCHIVE_OK); 292} 293 294/* 295 * Return the next block of decompressed data. 296 */ 297static ssize_t 298lz4_filter_read(struct archive_read_filter *self, const void **p) 299{ 300 struct private_data *state = (struct private_data *)self->data; 301 ssize_t ret; 302 303 if (state->eof) { 304 *p = NULL; 305 return (0); 306 } 307 308 __archive_read_filter_consume(self->upstream, state->unconsumed); 309 state->unconsumed = 0; 310 311 switch (state->stage) { 312 case SELECT_STREAM: 313 break; 314 case READ_DEFAULT_STREAM: 315 case READ_LEGACY_STREAM: 316 /* Reading a lz4 stream already failed. */ 317 archive_set_error(&self->archive->archive, 318 ARCHIVE_ERRNO_MISC, "Invalid sequence."); 319 return (ARCHIVE_FATAL); 320 case READ_DEFAULT_BLOCK: 321 ret = lz4_filter_read_default_stream(self, p); 322 if (ret != 0 || state->stage != SELECT_STREAM) 323 return ret; 324 break; 325 case READ_LEGACY_BLOCK: 326 ret = lz4_filter_read_legacy_stream(self, p); 327 if (ret != 0 || state->stage != SELECT_STREAM) 328 return ret; 329 break; 330 default: 331 archive_set_error(&self->archive->archive, 332 ARCHIVE_ERRNO_MISC, "Program error."); 333 return (ARCHIVE_FATAL); 334 break; 335 } 336 337 while (state->stage == SELECT_STREAM) { 338 const char *read_buf; 339 340 /* Read a magic number. */ 341 read_buf = __archive_read_filter_ahead(self->upstream, 4, 342 NULL); 343 if (read_buf == NULL) { 344 state->eof = 1; 345 *p = NULL; 346 return (0); 347 } 348 uint32_t number = archive_le32dec(read_buf); 349 __archive_read_filter_consume(self->upstream, 4); 350 if (number == LZ4_MAGICNUMBER) 351 return lz4_filter_read_default_stream(self, p); 352 else if (number == LZ4_LEGACY) 353 return lz4_filter_read_legacy_stream(self, p); 354 else if ((number & ~0xF) == LZ4_SKIPPABLED) { 355 read_buf = __archive_read_filter_ahead( 356 self->upstream, 4, NULL); 357 if (read_buf == NULL) { 358 archive_set_error( 359 &self->archive->archive, 360 ARCHIVE_ERRNO_MISC, 361 "Malformed lz4 data"); 362 return (ARCHIVE_FATAL); 363 } 364 uint32_t skip_bytes = archive_le32dec(read_buf); 365 __archive_read_filter_consume(self->upstream, 366 4 + skip_bytes); 367 } else { 368 /* Ignore following unrecognized data. */ 369 state->eof = 1; 370 *p = NULL; 371 return (0); 372 } 373 } 374 state->eof = 1; 375 *p = NULL; 376 return (0); 377} 378 379static int 380lz4_filter_read_descriptor(struct archive_read_filter *self) 381{ 382 struct private_data *state = (struct private_data *)self->data; 383 const char *read_buf; 384 ssize_t bytes_remaining; 385 ssize_t descriptor_bytes; 386 unsigned char flag, bd; 387 unsigned int chsum, chsum_verifier; 388 389 /* Make sure we have 2 bytes for flags. */ 390 read_buf = __archive_read_filter_ahead(self->upstream, 2, 391 &bytes_remaining); 392 if (read_buf == NULL) { 393 archive_set_error(&self->archive->archive, 394 ARCHIVE_ERRNO_MISC, 395 "truncated lz4 input"); 396 return (ARCHIVE_FATAL); 397 } 398 399 /* 400 Parse flags. 401 */ 402 flag = (unsigned char)read_buf[0]; 403 /* Verify version number. */ 404 if ((flag & 0xc0) != 1<<6) 405 goto malformed_error; 406 /* A reserved bit must be zero. */ 407 if (flag & 0x02) 408 goto malformed_error; 409 state->flags.block_independence = (flag & 0x20) != 0; 410 state->flags.block_checksum = (flag & 0x10)?4:0; 411 state->flags.stream_size = (flag & 0x08) != 0; 412 state->flags.stream_checksum = (flag & 0x04) != 0; 413 state->flags.preset_dictionary = (flag & 0x01) != 0; 414 415 /* BD */ 416 bd = (unsigned char)read_buf[1]; 417 /* Reserved bits must be zero. */ 418 if (bd & 0x8f) 419 goto malformed_error; 420 /* Get a maxinum block size. */ 421 switch (read_buf[1] >> 4) { 422 case 4: /* 64 KB */ 423 state->flags.block_maximum_size = 64 * 1024; 424 break; 425 case 5: /* 256 KB */ 426 state->flags.block_maximum_size = 256 * 1024; 427 break; 428 case 6: /* 1 MB */ 429 state->flags.block_maximum_size = 1024 * 1024; 430 break; 431 case 7: /* 4 MB */ 432 state->flags.block_maximum_size = 4 * 1024 * 1024; 433 break; 434 default: 435 goto malformed_error; 436 } 437 438 /* Read the whole descriptor in a stream block. */ 439 descriptor_bytes = 3; 440 if (state->flags.stream_size) 441 descriptor_bytes += 8; 442 if (state->flags.preset_dictionary) 443 descriptor_bytes += 4; 444 if (bytes_remaining < descriptor_bytes) { 445 read_buf = __archive_read_filter_ahead(self->upstream, 446 descriptor_bytes, &bytes_remaining); 447 if (read_buf == NULL) { 448 archive_set_error(&self->archive->archive, 449 ARCHIVE_ERRNO_MISC, 450 "truncated lz4 input"); 451 return (ARCHIVE_FATAL); 452 } 453 } 454 /* Check if a descriptor is corrupted */ 455 chsum = __archive_xxhash.XXH32(read_buf, (int)descriptor_bytes -1, 0); 456 chsum = (chsum >> 8) & 0xff; 457 chsum_verifier = read_buf[descriptor_bytes-1] & 0xff; 458 if (chsum != chsum_verifier) 459 goto malformed_error; 460 461 __archive_read_filter_consume(self->upstream, descriptor_bytes); 462 463 /* Make sure we have an enough buffer for uncompressed data. */ 464 if (lz4_allocate_out_block(self) != ARCHIVE_OK) 465 return (ARCHIVE_FATAL); 466 if (state->flags.stream_checksum) 467 state->xxh32_state = __archive_xxhash.XXH32_init(0); 468 469 state->decoded_size = 0; 470 /* Success */ 471 return (ARCHIVE_OK); 472malformed_error: 473 archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC, 474 "malformed lz4 data"); 475 return (ARCHIVE_FATAL); 476} 477 478static ssize_t 479lz4_filter_read_data_block(struct archive_read_filter *self, const void **p) 480{ 481 struct private_data *state = (struct private_data *)self->data; 482 ssize_t compressed_size; 483 const char *read_buf; 484 ssize_t bytes_remaining; 485 int checksum_size; 486 ssize_t uncompressed_size; 487 size_t prefix64k; 488 489 *p = NULL; 490 491 /* Make sure we have 4 bytes for a block size. */ 492 read_buf = __archive_read_filter_ahead(self->upstream, 4, 493 &bytes_remaining); 494 if (read_buf == NULL) 495 goto truncated_error; 496 compressed_size = archive_le32dec(read_buf); 497 if ((compressed_size & ~(1 << 31)) > state->flags.block_maximum_size) 498 goto malformed_error; 499 /* A compressed size == 0 means the end of stream blocks. */ 500 if (compressed_size == 0) { 501 __archive_read_filter_consume(self->upstream, 4); 502 return 0; 503 } 504 505 checksum_size = state->flags.block_checksum; 506 /* Check if the block is uncompressed. */ 507 if (compressed_size & (1 << 31)) { 508 compressed_size &= ~(1 << 31); 509 uncompressed_size = compressed_size; 510 } else 511 uncompressed_size = 0;/* Unknown yet. */ 512 513 /* 514 Unfortunately, lz4 decompression API requires a whole block 515 for its decompression speed, so we read a whole block and allocate 516 a huge buffer used for decoded data. 517 */ 518 read_buf = __archive_read_filter_ahead(self->upstream, 519 4 + compressed_size + checksum_size, &bytes_remaining); 520 if (read_buf == NULL) 521 goto truncated_error; 522 523 /* Optional process, checking a block sum. */ 524 if (checksum_size) { 525 unsigned int chsum = __archive_xxhash.XXH32( 526 read_buf + 4, (int)compressed_size, 0); 527 unsigned int chsum_block = 528 archive_le32dec(read_buf + 4 + compressed_size); 529 if (chsum != chsum_block) 530 goto malformed_error; 531 } 532 533 534 /* If the block is uncompressed, there is nothing to do. */ 535 if (uncompressed_size) { 536 /* Prepare a prefix 64k block for next block. */ 537 if (!state->flags.block_independence) { 538 prefix64k = 64 * 1024; 539 if (uncompressed_size < (ssize_t)prefix64k) { 540 memcpy(state->out_block 541 + prefix64k - uncompressed_size, 542 read_buf + 4, 543 uncompressed_size); 544 memset(state->out_block, 0, 545 prefix64k - uncompressed_size); 546 } else { 547 memcpy(state->out_block, 548 read_buf + 4 549 + uncompressed_size - prefix64k, 550 prefix64k); 551 } 552 state->decoded_size = 0; 553 } 554 state->unconsumed = 4 + uncompressed_size + checksum_size; 555 *p = read_buf + 4; 556 return uncompressed_size; 557 } 558 559 /* 560 Decompress a block data. 561 */ 562 if (state->flags.block_independence) { 563 prefix64k = 0; 564 uncompressed_size = LZ4_decompress_safe(read_buf + 4, 565 state->out_block, (int)compressed_size, 566 state->flags.block_maximum_size); 567 } else { 568 prefix64k = 64 * 1024; 569 if (state->decoded_size) { 570 if (state->decoded_size < prefix64k) { 571 memmove(state->out_block 572 + prefix64k - state->decoded_size, 573 state->out_block + prefix64k, 574 state->decoded_size); 575 memset(state->out_block, 0, 576 prefix64k - state->decoded_size); 577 } else { 578 memmove(state->out_block, 579 state->out_block + state->decoded_size, 580 prefix64k); 581 } 582 } 583#if LZ4_VERSION_MAJOR >= 1 && LZ4_VERSION_MINOR >= 7 584 uncompressed_size = LZ4_decompress_safe_usingDict( 585 read_buf + 4, 586 state->out_block + prefix64k, (int)compressed_size, 587 state->flags.block_maximum_size, 588 state->out_block, 589 prefix64k); 590#else 591 uncompressed_size = LZ4_decompress_safe_withPrefix64k( 592 read_buf + 4, 593 state->out_block + prefix64k, (int)compressed_size, 594 state->flags.block_maximum_size); 595#endif 596 } 597 598 /* Check if an error occurred in the decompression process. */ 599 if (uncompressed_size < 0) { 600 archive_set_error(&(self->archive->archive), 601 ARCHIVE_ERRNO_MISC, "lz4 decompression failed"); 602 return (ARCHIVE_FATAL); 603 } 604 605 state->unconsumed = 4 + compressed_size + checksum_size; 606 *p = state->out_block + prefix64k; 607 state->decoded_size = uncompressed_size; 608 return uncompressed_size; 609 610malformed_error: 611 archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC, 612 "malformed lz4 data"); 613 return (ARCHIVE_FATAL); 614truncated_error: 615 archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC, 616 "truncated lz4 input"); 617 return (ARCHIVE_FATAL); 618} 619 620static ssize_t 621lz4_filter_read_default_stream(struct archive_read_filter *self, const void **p) 622{ 623 struct private_data *state = (struct private_data *)self->data; 624 const char *read_buf; 625 ssize_t bytes_remaining; 626 ssize_t ret; 627 628 if (state->stage == SELECT_STREAM) { 629 state->stage = READ_DEFAULT_STREAM; 630 /* First, read a desciprtor. */ 631 if((ret = lz4_filter_read_descriptor(self)) != ARCHIVE_OK) 632 return (ret); 633 state->stage = READ_DEFAULT_BLOCK; 634 } 635 /* Decompress a block. */ 636 ret = lz4_filter_read_data_block(self, p); 637 638 /* If the end of block is detected, change the filter status 639 to read next stream. */ 640 if (ret == 0 && *p == NULL) 641 state->stage = SELECT_STREAM; 642 643 /* Optional process, checking a stream sum. */ 644 if (state->flags.stream_checksum) { 645 if (state->stage == SELECT_STREAM) { 646 unsigned int checksum; 647 unsigned int checksum_stream; 648 read_buf = __archive_read_filter_ahead(self->upstream, 649 4, &bytes_remaining); 650 if (read_buf == NULL) { 651 archive_set_error(&self->archive->archive, 652 ARCHIVE_ERRNO_MISC, "truncated lz4 input"); 653 return (ARCHIVE_FATAL); 654 } 655 checksum = archive_le32dec(read_buf); 656 __archive_read_filter_consume(self->upstream, 4); 657 checksum_stream = __archive_xxhash.XXH32_digest( 658 state->xxh32_state); 659 state->xxh32_state = NULL; 660 if (checksum != checksum_stream) { 661 archive_set_error(&self->archive->archive, 662 ARCHIVE_ERRNO_MISC, 663 "lz4 stream cheksum error"); 664 return (ARCHIVE_FATAL); 665 } 666 } else if (ret > 0) 667 __archive_xxhash.XXH32_update(state->xxh32_state, 668 *p, (int)ret); 669 } 670 return (ret); 671} 672 673static ssize_t 674lz4_filter_read_legacy_stream(struct archive_read_filter *self, const void **p) 675{ 676 struct private_data *state = (struct private_data *)self->data; 677 int compressed; 678 const char *read_buf; 679 ssize_t ret; 680 681 *p = NULL; 682 ret = lz4_allocate_out_block_for_legacy(self); 683 if (ret != ARCHIVE_OK) 684 return ret; 685 686 /* Make sure we have 4 bytes for a block size. */ 687 read_buf = __archive_read_filter_ahead(self->upstream, 4, NULL); 688 if (read_buf == NULL) { 689 if (state->stage == SELECT_STREAM) { 690 state->stage = READ_LEGACY_STREAM; 691 archive_set_error(&self->archive->archive, 692 ARCHIVE_ERRNO_MISC, 693 "truncated lz4 input"); 694 return (ARCHIVE_FATAL); 695 } 696 state->stage = SELECT_STREAM; 697 return 0; 698 } 699 state->stage = READ_LEGACY_BLOCK; 700 compressed = archive_le32dec(read_buf); 701 if (compressed > LZ4_COMPRESSBOUND(LEGACY_BLOCK_SIZE)) { 702 state->stage = SELECT_STREAM; 703 return 0; 704 } 705 706 /* Make sure we have a whole block. */ 707 read_buf = __archive_read_filter_ahead(self->upstream, 708 4 + compressed, NULL); 709 ret = LZ4_decompress_safe(read_buf + 4, state->out_block, 710 compressed, (int)state->out_block_size); 711 if (ret < 0) { 712 archive_set_error(&(self->archive->archive), 713 ARCHIVE_ERRNO_MISC, "lz4 decompression failed"); 714 return (ARCHIVE_FATAL); 715 } 716 *p = state->out_block; 717 state->unconsumed = 4 + compressed; 718 return ret; 719} 720 721/* 722 * Clean up the decompressor. 723 */ 724static int 725lz4_filter_close(struct archive_read_filter *self) 726{ 727 struct private_data *state; 728 int ret = ARCHIVE_OK; 729 730 state = (struct private_data *)self->data; 731 free(state->xxh32_state); 732 free(state->out_block); 733 free(state); 734 return (ret); 735} 736 737#endif /* HAVE_LIBLZ4 */ 738