src/journal/compress.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25
  26 #ifdef HAVE_XZ
  27 #  include <lzma.h>
  28 #endif
  29
  30 #ifdef HAVE_LZ4
  31 #  include <lz4.h>
  32 #endif
  33
  34 #include "compress.h"
  35 #include "macro.h"
  36 #include "util.h"
  37 #include "sparse-endian.h"
  38 #include "journal-def.h"
  39
  40 #define ALIGN_8(l) ALIGN_TO(l, sizeof(size_t))
  41
  42 static const char* const object_compressed_table[_OBJECT_COMPRESSED_MAX] = {
  43         [OBJECT_COMPRESSED_XZ] = "XZ",
  44         [OBJECT_COMPRESSED_LZ4] = "LZ4",
  45 };
  46
  47 DEFINE_STRING_TABLE_LOOKUP(object_compressed, int);
  48
  49 int compress_blob_xz(const void *src, uint64_t src_size, void *dst, size_t *dst_size) {
  50 #ifdef HAVE_XZ
  51         static const lzma_options_lzma opt = {
  52                 1u << 20u, NULL, 0, LZMA_LC_DEFAULT, LZMA_LP_DEFAULT,
  53                 LZMA_PB_DEFAULT, LZMA_MODE_FAST, 128, LZMA_MF_HC3, 4};
  54         static const lzma_filter filters[2] = {
  55                 {LZMA_FILTER_LZMA2, (lzma_options_lzma*) &opt},
  56                 {LZMA_VLI_UNKNOWN, NULL}
  57         };
  58         lzma_ret ret;
  59         size_t out_pos = 0;
  60
  61         assert(src);
  62         assert(src_size > 0);
  63         assert(dst);
  64         assert(dst_size);
  65
  66         /* Returns < 0 if we couldn't compress the data or the
  67          * compressed result is longer than the original */
  68
  69         if (src_size < 80)
  70                 return -ENOBUFS;
  71
  72         ret = lzma_stream_buffer_encode((lzma_filter*) filters, LZMA_CHECK_NONE, NULL,
  73                                         src, src_size, dst, &out_pos, src_size - 1);
  74         if (ret != LZMA_OK)
  75                 return -ENOBUFS;
  76
  77         *dst_size = out_pos;
  78         return 0;
  79 #else
  80         return -EPROTONOSUPPORT;
  81 #endif
  82 }
  83
  84 int compress_blob_lz4(const void *src, uint64_t src_size, void *dst, size_t *dst_size) {
  85 #ifdef HAVE_LZ4
  86         int r;
  87
  88         assert(src);
  89         assert(src_size > 0);
  90         assert(dst);
  91         assert(dst_size);
  92
  93         /* Returns < 0 if we couldn't compress the data or the
  94          * compressed result is longer than the original */
  95
  96         if (src_size < 9)
  97                 return -ENOBUFS;
  98
  99         r = LZ4_compress_limitedOutput(src, dst + 8, src_size, src_size - 8 - 1);
 100         if (r <= 0)
 101                 return -ENOBUFS;
 102
 103         *(le64_t*) dst = htole64(src_size);
 104         *dst_size = r + 8;
 105
 106         return 0;
 107 #else
 108         return -EPROTONOSUPPORT;
 109 #endif
 110 }
 111
 112
 113 int decompress_blob_xz(const void *src, uint64_t src_size,
 114                        void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max) {
 115
 116 #ifdef HAVE_XZ
 117         _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
 118         lzma_ret ret;
 119         size_t space;
 120
 121         assert(src);
 122         assert(src_size > 0);
 123         assert(dst);
 124         assert(dst_alloc_size);
 125         assert(dst_size);
 126         assert(*dst_alloc_size == 0 || *dst);
 127
 128         ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
 129         if (ret != LZMA_OK)
 130                 return -ENOMEM;
 131
 132         space = MIN(src_size * 2, dst_max ?: (size_t) -1);
 133         if (!greedy_realloc(dst, dst_alloc_size, space, 1))
 134                 return -ENOMEM;
 135
 136         s.next_in = src;
 137         s.avail_in = src_size;
 138
 139         s.next_out = *dst;
 140         s.avail_out = space;
 141
 142         for (;;) {
 143                 size_t used;
 144
 145                 ret = lzma_code(&s, LZMA_FINISH);
 146
 147                 if (ret == LZMA_STREAM_END)
 148                         break;
 149                 else if (ret != LZMA_OK)
 150                         return -ENOMEM;
 151
 152                 if (dst_max > 0 && (space - s.avail_out) >= dst_max)
 153                         break;
 154                 else if (dst_max > 0 && space == dst_max)
 155                         return -ENOBUFS;
 156
 157                 used = space - s.avail_out;
 158                 space = MIN(2 * space, dst_max ?: (size_t) -1);
 159                 if (!greedy_realloc(dst, dst_alloc_size, space, 1))
 160                         return -ENOMEM;
 161
 162                 s.avail_out = space - used;
 163                 s.next_out = *dst + used;
 164         }
 165
 166         *dst_size = space - s.avail_out;
 167         return 0;
 168 #else
 169         return -EPROTONOSUPPORT;
 170 #endif
 171 }
 172
 173 int decompress_blob_lz4(const void *src, uint64_t src_size,
 174                         void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max) {
 175
 176 #ifdef HAVE_LZ4
 177         char* out;
 178         int r, size; /* LZ4 uses int for size */
 179
 180         assert(src);
 181         assert(src_size > 0);
 182         assert(dst);
 183         assert(dst_alloc_size);
 184         assert(dst_size);
 185         assert(*dst_alloc_size == 0 || *dst);
 186
 187         if (src_size <= 8)
 188                 return -EBADMSG;
 189
 190         size = le64toh( *(le64_t*)src );
 191         if (size < 0 || (le64_t) size != *(le64_t*)src)
 192                 return -EFBIG;
 193         if ((size_t) size > *dst_alloc_size) {
 194                 out = realloc(*dst, size);
 195                 if (!out)
 196                         return -ENOMEM;
 197                 *dst = out;
 198                 *dst_alloc_size = size;
 199         } else
 200                 out = *dst;
 201
 202         r = LZ4_decompress_safe(src + 8, out, src_size - 8, size);
 203         if (r < 0 || r != size)
 204                 return -EBADMSG;
 205
 206         *dst_size = size;
 207         return 0;
 208 #else
 209         return -EPROTONOSUPPORT;
 210 #endif
 211 }
 212
 213 int decompress_blob(int compression,
 214                     const void *src, uint64_t src_size,
 215                     void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max) {
 216         if (compression == OBJECT_COMPRESSED_XZ)
 217                 return decompress_blob_xz(src, src_size,
 218                                           dst, dst_alloc_size, dst_size, dst_max);
 219         else if (compression == OBJECT_COMPRESSED_LZ4)
 220                 return decompress_blob_lz4(src, src_size,
 221                                            dst, dst_alloc_size, dst_size, dst_max);
 222         else
 223                 return -EBADMSG;
 224 }
 225
 226
 227 int decompress_startswith_xz(const void *src, uint64_t src_size,
 228                              void **buffer, size_t *buffer_size,
 229                              const void *prefix, size_t prefix_len,
 230                              uint8_t extra) {
 231
 232 #ifdef HAVE_XZ
 233         _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
 234         lzma_ret ret;
 235
 236         /* Checks whether the decompressed blob starts with the
 237          * mentioned prefix. The byte extra needs to follow the
 238          * prefix */
 239
 240         assert(src);
 241         assert(src_size > 0);
 242         assert(buffer);
 243         assert(buffer_size);
 244         assert(prefix);
 245         assert(*buffer_size == 0 || *buffer);
 246
 247         ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
 248         if (ret != LZMA_OK)
 249                 return -EBADMSG;
 250
 251         if (!(greedy_realloc(buffer, buffer_size, ALIGN_8(prefix_len + 1), 1)))
 252                 return -ENOMEM;
 253
 254         s.next_in = src;
 255         s.avail_in = src_size;
 256
 257         s.next_out = *buffer;
 258         s.avail_out = *buffer_size;
 259
 260         for (;;) {
 261                 ret = lzma_code(&s, LZMA_FINISH);
 262
 263                 if (ret != LZMA_STREAM_END && ret != LZMA_OK)
 264                         return -EBADMSG;
 265
 266                 if (*buffer_size - s.avail_out >= prefix_len + 1)
 267                         return memcmp(*buffer, prefix, prefix_len) == 0 &&
 268                                 ((const uint8_t*) *buffer)[prefix_len] == extra;
 269
 270                 if (ret == LZMA_STREAM_END)
 271                         return 0;
 272
 273                 s.avail_out += *buffer_size;
 274
 275                 if (!(greedy_realloc(buffer, buffer_size, *buffer_size * 2, 1)))
 276                         return -ENOMEM;
 277
 278                 s.next_out = *buffer + *buffer_size - s.avail_out;
 279         }
 280
 281 #else
 282         return -EPROTONOSUPPORT;
 283 #endif
 284 }
 285
 286 int decompress_startswith_lz4(const void *src, uint64_t src_size,
 287                               void **buffer, size_t *buffer_size,
 288                               const void *prefix, size_t prefix_len,
 289                               uint8_t extra) {
 290 #ifdef HAVE_LZ4
 291         /* Checks whether the decompressed blob starts with the
 292          * mentioned prefix. The byte extra needs to follow the
 293          * prefix */
 294
 295         int r;
 296
 297         assert(src);
 298         assert(src_size > 0);
 299         assert(buffer);
 300         assert(buffer_size);
 301         assert(prefix);
 302         assert(*buffer_size == 0 || *buffer);
 303
 304         if (src_size <= 8)
 305                 return -EBADMSG;
 306
 307         if (!(greedy_realloc(buffer, buffer_size, ALIGN_8(prefix_len + 1), 1)))
 308                 return -ENOMEM;
 309
 310         r = LZ4_decompress_safe_partial(src + 8, *buffer, src_size - 8,
 311                                         prefix_len + 1, *buffer_size);
 312
 313         if (r < 0)
 314                 return -EBADMSG;
 315         if ((unsigned) r >= prefix_len + 1)
 316                 return memcmp(*buffer, prefix, prefix_len) == 0 &&
 317                         ((const uint8_t*) *buffer)[prefix_len] == extra;
 318         else
 319                 return 0;
 320
 321 #else
 322         return -EPROTONOSUPPORT;
 323 #endif
 324 }
 325
 326 int decompress_startswith(int compression,
 327                           const void *src, uint64_t src_size,
 328                           void **buffer, size_t *buffer_size,
 329                           const void *prefix, size_t prefix_len,
 330                           uint8_t extra) {
 331         if (compression == OBJECT_COMPRESSED_XZ)
 332                 return decompress_startswith_xz(src, src_size,
 333                                                 buffer, buffer_size,
 334                                                 prefix, prefix_len,
 335                                                 extra);
 336         else if (compression == OBJECT_COMPRESSED_LZ4)
 337                 return decompress_startswith_lz4(src, src_size,
 338                                                  buffer, buffer_size,
 339                                                  prefix, prefix_len,
 340                                                  extra);
 341         else
 342                 return -EBADMSG;
 343 }
 344
 345 int compress_stream_xz(int fdf, int fdt, off_t max_bytes) {
 346 #ifdef HAVE_XZ
 347         _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
 348         lzma_ret ret;
 349
 350         uint8_t buf[BUFSIZ], out[BUFSIZ];
 351         lzma_action action = LZMA_RUN;
 352
 353         assert(fdf >= 0);
 354         assert(fdt >= 0);
 355
 356         ret = lzma_easy_encoder(&s, LZMA_PRESET_DEFAULT, LZMA_CHECK_CRC64);
 357         if (ret != LZMA_OK) {
 358                 log_error("Failed to initialize XZ encoder: code %u", ret);
 359                 return -EINVAL;
 360         }
 361
 362         for (;;) {
 363                 if (s.avail_in == 0 && action == LZMA_RUN) {
 364                         size_t m = sizeof(buf);
 365                         ssize_t n;
 366
 367                         if (max_bytes != -1 && m > (size_t) max_bytes)
 368                                 m = max_bytes;
 369
 370                         n = read(fdf, buf, m);
 371                         if (n < 0)
 372                                 return -errno;
 373                         if (n == 0)
 374                                 action = LZMA_FINISH;
 375                         else {
 376                                 s.next_in = buf;
 377                                 s.avail_in = n;
 378
 379                                 if (max_bytes != -1) {
 380                                         assert(max_bytes >= n);
 381                                         max_bytes -= n;
 382                                 }
 383                         }
 384                 }
 385
 386                 if (s.avail_out == 0) {
 387                         s.next_out = out;
 388                         s.avail_out = sizeof(out);
 389                 }
 390
 391                 ret = lzma_code(&s, action);
 392                 if (ret != LZMA_OK && ret != LZMA_STREAM_END) {
 393                         log_error("Compression failed: code %u", ret);
 394                         return -EBADMSG;
 395                 }
 396
 397                 if (s.avail_out == 0 || ret == LZMA_STREAM_END) {
 398                         ssize_t n, k;
 399
 400                         n = sizeof(out) - s.avail_out;
 401
 402                         k = loop_write(fdt, out, n, false);
 403                         if (k < 0)
 404                                 return k;
 405
 406                         if (ret == LZMA_STREAM_END) {
 407                                 log_debug("XZ compression finished (%"PRIu64" -> %"PRIu64" bytes, %.1f%%)",
 408                                           s.total_in, s.total_out,
 409                                           (double) s.total_out / s.total_in * 100);
 410
 411                                 return 0;
 412                         }
 413                 }
 414         }
 415 #else
 416         return -EPROTONOSUPPORT;
 417 #endif
 418 }
 419
 420 #define LZ4_BUFSIZE (512*1024)
 421
 422 int compress_stream_lz4(int fdf, int fdt, off_t max_bytes) {
 423
 424 #ifdef HAVE_LZ4
 425
 426         _cleanup_free_ char *buf1 = NULL, *buf2 = NULL, *out = NULL;
 427         char *buf;
 428         LZ4_stream_t lz4_data = {};
 429         le32_t header;
 430         size_t total_in = 0, total_out = sizeof(header);
 431         ssize_t n;
 432
 433         assert(fdf >= 0);
 434         assert(fdt >= 0);
 435
 436         buf1 = malloc(LZ4_BUFSIZE);
 437         buf2 = malloc(LZ4_BUFSIZE);
 438         out = malloc(LZ4_COMPRESSBOUND(LZ4_BUFSIZE));
 439         if (!buf1 || !buf2 || !out)
 440                 return log_oom();
 441
 442         buf = buf1;
 443         for (;;) {
 444                 size_t m;
 445                 int r;
 446
 447                 m = LZ4_BUFSIZE;
 448                 if (max_bytes != -1 && m > (size_t) max_bytes - total_in)
 449                         m = max_bytes - total_in;
 450
 451                 n = read(fdf, buf, m);
 452                 if (n < 0)
 453                         return -errno;
 454                 if (n == 0)
 455                         break;
 456
 457                 total_in += n;
 458
 459                 r = LZ4_compress_continue(&lz4_data, buf, out, n);
 460                 if (r == 0) {
 461                         log_error("LZ4 compression failed.");
 462                         return -EBADMSG;
 463                 }
 464
 465                 header = htole32(r);
 466                 errno = 0;
 467
 468                 n = write(fdt, &header, sizeof(header));
 469                 if (n < 0)
 470                         return -errno;
 471                 if (n != sizeof(header))
 472                         return errno ? -errno : -EIO;
 473
 474                 n = loop_write(fdt, out, r, false);
 475                 if (n < 0)
 476                         return n;
 477
 478                 total_out += sizeof(header) + r;
 479
 480                 buf = buf == buf1 ? buf2 : buf1;
 481         }
 482
 483         header = htole32(0);
 484         n = write(fdt, &header, sizeof(header));
 485         if (n < 0)
 486                 return -errno;
 487         if (n != sizeof(header))
 488                 return errno ? -errno : -EIO;
 489
 490         log_debug("LZ4 compression finished (%zu -> %zu bytes, %.1f%%)",
 491                   total_in, total_out,
 492                   (double) total_out / total_in * 100);
 493
 494         return 0;
 495 #else
 496         return -EPROTONOSUPPORT;
 497 #endif
 498 }
 499
 500 int decompress_stream_xz(int fdf, int fdt, off_t max_bytes) {
 501
 502 #ifdef HAVE_XZ
 503         _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
 504         lzma_ret ret;
 505
 506         uint8_t buf[BUFSIZ], out[BUFSIZ];
 507         lzma_action action = LZMA_RUN;
 508
 509         assert(fdf >= 0);
 510         assert(fdt >= 0);
 511
 512         ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
 513         if (ret != LZMA_OK) {
 514                 log_error("Failed to initialize XZ decoder: code %u", ret);
 515                 return -ENOMEM;
 516         }
 517
 518         for (;;) {
 519                 if (s.avail_in == 0 && action == LZMA_RUN) {
 520                         ssize_t n;
 521
 522                         n = read(fdf, buf, sizeof(buf));
 523                         if (n < 0)
 524                                 return -errno;
 525                         if (n == 0)
 526                                 action = LZMA_FINISH;
 527                         else {
 528                                 s.next_in = buf;
 529                                 s.avail_in = n;
 530                         }
 531                 }
 532
 533                 if (s.avail_out == 0) {
 534                         s.next_out = out;
 535                         s.avail_out = sizeof(out);
 536                 }
 537
 538                 ret = lzma_code(&s, action);
 539                 if (ret != LZMA_OK && ret != LZMA_STREAM_END) {
 540                         log_error("Decompression failed: code %u", ret);
 541                         return -EBADMSG;
 542                 }
 543
 544                 if (s.avail_out == 0 || ret == LZMA_STREAM_END) {
 545                         ssize_t n, k;
 546
 547                         n = sizeof(out) - s.avail_out;
 548
 549                         if (max_bytes != -1) {
 550                                 if (max_bytes < n)
 551                                         return -EFBIG;
 552
 553                                 max_bytes -= n;
 554                         }
 555
 556                         k = loop_write(fdt, out, n, false);
 557                         if (k < 0)
 558                                 return k;
 559
 560                         if (ret == LZMA_STREAM_END) {
 561                                 log_debug("XZ decompression finished (%"PRIu64" -> %"PRIu64" bytes, %.1f%%)",
 562                                           s.total_in, s.total_out,
 563                                           (double) s.total_out / s.total_in * 100);
 564
 565                                 return 0;
 566                         }
 567                 }
 568         }
 569 #else
 570         log_error("Cannot decompress file. Compiled without XZ support.");
 571         return -EPROTONOSUPPORT;
 572 #endif
 573 }
 574
 575 int decompress_stream_lz4(int fdf, int fdt, off_t max_bytes) {
 576
 577 #ifdef HAVE_LZ4
 578         _cleanup_free_ char *buf = NULL, *out = NULL;
 579         size_t buf_size = 0;
 580         LZ4_streamDecode_t lz4_data = {};
 581         le32_t header;
 582         size_t total_in = sizeof(header), total_out = 0;
 583
 584         assert(fdf >= 0);
 585         assert(fdt >= 0);
 586
 587         out = malloc(4*LZ4_BUFSIZE);
 588         if (!out)
 589                 return log_oom();
 590
 591         for (;;) {
 592                 ssize_t m;
 593                 int r;
 594
 595                 r = loop_read_exact(fdf, &header, sizeof(header), false);
 596                 if (r < 0)
 597                         return r;
 598
 599                 m = le32toh(header);
 600                 if (m == 0)
 601                         break;
 602
 603                 /* We refuse to use a bigger decompression buffer than
 604                  * the one used for compression by 4 times. This means
 605                  * that compression buffer size can be enlarged 4
 606                  * times. This can be changed, but old binaries might
 607                  * not accept buffers compressed by newer binaries then.
 608                  */
 609                 if (m > LZ4_COMPRESSBOUND(LZ4_BUFSIZE * 4)) {
 610                         log_error("Compressed stream block too big: %zd bytes", m);
 611                         return -EBADMSG;
 612                 }
 613
 614                 total_in += sizeof(header) + m;
 615
 616                 if (!GREEDY_REALLOC(buf, buf_size, m))
 617                         return log_oom();
 618
 619                 r = loop_read_exact(fdf, buf, m, false);
 620                 if (r < 0)
 621                         return r;
 622
 623                 r = LZ4_decompress_safe_continue(&lz4_data, buf, out, m, 4*LZ4_BUFSIZE);
 624                 if (r <= 0)
 625                         log_error("LZ4 decompression failed.");
 626
 627                 total_out += r;
 628
 629                 if (max_bytes != -1 && total_out > (size_t) max_bytes) {
 630                         log_debug("Decompressed stream longer than %zd bytes", max_bytes);
 631                         return -EFBIG;
 632                 }
 633
 634                 r = loop_write(fdt, out, r, false);
 635                 if (r < 0)
 636                         return r;
 637         }
 638
 639         log_debug("LZ4 decompression finished (%zu -> %zu bytes, %.1f%%)",
 640                   total_in, total_out,
 641                   (double) total_out / total_in * 100);
 642
 643         return 0;
 644 #else
 645         log_error("Cannot decompress file. Compiled without LZ4 support.");
 646         return -EPROTONOSUPPORT;
 647 #endif
 648 }
 649
 650 int decompress_stream(const char *filename, int fdf, int fdt, off_t max_bytes) {
 651
 652         if (endswith(filename, ".lz4"))
 653                 return decompress_stream_lz4(fdf, fdt, max_bytes);
 654         else if (endswith(filename, ".xz"))
 655                 return decompress_stream_xz(fdf, fdt, max_bytes);
 656         else
 657                 return -EPROTONOSUPPORT;
 658 }