arch/all-pc/boot/grub2-aros/grub-core/io/lzopio.c

   1 /* lzopio.c - decompression support for lzop */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2011  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/err.h>
  21 #include <grub/mm.h>
  22 #include <grub/file.h>
  23 #include <grub/fs.h>
  24 #include <grub/dl.h>
  25 #include <grub/crypto.h>
  26 #include <minilzo.h>
  27
  28 GRUB_MOD_LICENSE ("GPLv3+");
  29
  30 #define LZOP_MAGIC "\x89\x4c\x5a\x4f\x00\x0d\x0a\x1a\x0a"
  31 #define LZOP_MAGIC_SIZE 9
  32 #define LZOP_CHECK_SIZE 4
  33 #define LZOP_NEW_LIB 0x0940
  34
  35 /* Header flags - copied from conf.h of LZOP source code.  */
  36 #define F_ADLER32_D     0x00000001L
  37 #define F_ADLER32_C     0x00000002L
  38 #define F_STDIN         0x00000004L
  39 #define F_STDOUT        0x00000008L
  40 #define F_NAME_DEFAULT  0x00000010L
  41 #define F_DOSISH        0x00000020L
  42 #define F_H_EXTRA_FIELD 0x00000040L
  43 #define F_H_GMTDIFF     0x00000080L
  44 #define F_CRC32_D       0x00000100L
  45 #define F_CRC32_C       0x00000200L
  46 #define F_MULTIPART     0x00000400L
  47 #define F_H_FILTER      0x00000800L
  48 #define F_H_CRC32       0x00001000L
  49 #define F_H_PATH        0x00002000L
  50 #define F_MASK          0x00003FFFL
  51
  52 struct block_header
  53 {
  54   grub_uint32_t usize;
  55   grub_uint32_t csize;
  56   grub_uint32_t ucheck;
  57   grub_uint32_t ccheck;
  58   unsigned char *cdata;
  59   unsigned char *udata;
  60 };
  61
  62 struct grub_lzopio
  63 {
  64   grub_file_t file;
  65   int has_ccheck;
  66   int has_ucheck;
  67   const gcry_md_spec_t *ucheck_fun;
  68   const gcry_md_spec_t *ccheck_fun;
  69   grub_off_t saved_off;         /* Rounded down to block boundary.  */
  70   grub_off_t start_block_off;
  71   struct block_header block;
  72 };
  73
  74 typedef struct grub_lzopio *grub_lzopio_t;
  75 static struct grub_fs grub_lzopio_fs;
  76
  77 /* Some helper functions. On errors memory allocated by those function is free
  78  * either on close() so no risk of leaks. This makes functions simpler.  */
  79
  80 /* Read block header from file, after successful exit file points to
  81  * beginning of block data.  */
  82 static int
  83 read_block_header (struct grub_lzopio *lzopio)
  84 {
  85   lzopio->saved_off += lzopio->block.usize;
  86
  87   /* Free cached block data if any.  */
  88   grub_free (lzopio->block.udata);
  89   grub_free (lzopio->block.cdata);
  90   lzopio->block.udata = NULL;
  91   lzopio->block.cdata = NULL;
  92
  93   if (grub_file_read (lzopio->file, &lzopio->block.usize,
  94                       sizeof (lzopio->block.usize)) !=
  95       sizeof (lzopio->block.usize))
  96     return -1;
  97
  98   lzopio->block.usize = grub_be_to_cpu32 (lzopio->block.usize);
  99
 100   /* Last block has uncompressed data size == 0 and no other fields.  */
 101   if (lzopio->block.usize == 0)
 102     {
 103       if (grub_file_tell (lzopio->file) == grub_file_size (lzopio->file))
 104         return 0;
 105       else
 106         return -1;
 107     }
 108
 109   /* Read compressed data block size.  */
 110   if (grub_file_read (lzopio->file, &lzopio->block.csize,
 111                       sizeof (lzopio->block.csize)) !=
 112       sizeof (lzopio->block.csize))
 113     return -1;
 114
 115   lzopio->block.csize = grub_be_to_cpu32 (lzopio->block.csize);
 116
 117   /* Corrupted.  */
 118   if (lzopio->block.csize > lzopio->block.usize)
 119     return -1;
 120
 121   /* Read checksum of uncompressed data.  */
 122   if (lzopio->has_ucheck)
 123     {
 124       if (grub_file_read (lzopio->file, &lzopio->block.ucheck,
 125                           sizeof (lzopio->block.ucheck)) !=
 126           sizeof (lzopio->block.ucheck))
 127         return -1;
 128
 129       lzopio->block.ucheck = lzopio->block.ucheck;
 130     }
 131
 132   /* Read checksum of compressed data.  */
 133   if (lzopio->has_ccheck)
 134     {
 135       /* Incompressible data block.  */
 136       if (lzopio->block.csize == lzopio->block.usize)
 137         {
 138           lzopio->block.ccheck = lzopio->block.ucheck;
 139         }
 140       else
 141         {
 142           if (grub_file_read (lzopio->file, &lzopio->block.ccheck,
 143                               sizeof (lzopio->block.ccheck)) !=
 144               sizeof (lzopio->block.ccheck))
 145             return -1;
 146
 147           lzopio->block.ccheck = lzopio->block.ccheck;
 148         }
 149     }
 150
 151   return 0;
 152 }
 153
 154 /* Read block data into memory. File must be set to beginning of block data.
 155  * Can't be called on last block.  */
 156 static int
 157 read_block_data (struct grub_lzopio *lzopio)
 158 {
 159   lzopio->block.cdata = grub_malloc (lzopio->block.csize);
 160   if (!lzopio->block.cdata)
 161     return -1;
 162
 163   if (grub_file_read (lzopio->file, lzopio->block.cdata, lzopio->block.csize)
 164       != (grub_ssize_t) lzopio->block.csize)
 165     return -1;
 166
 167   if (lzopio->ccheck_fun)
 168     {
 169       grub_uint8_t computed_hash[GRUB_CRYPTO_MAX_MDLEN];
 170
 171       if (lzopio->ccheck_fun->mdlen > GRUB_CRYPTO_MAX_MDLEN)
 172         return -1;
 173
 174       grub_crypto_hash (lzopio->ccheck_fun, computed_hash,
 175                         lzopio->block.cdata,
 176                         lzopio->block.csize);
 177
 178       if (grub_memcmp
 179           (computed_hash, &lzopio->block.ccheck,
 180            sizeof (lzopio->block.ccheck)) != 0)
 181         return -1;
 182     }
 183
 184   return 0;
 185 }
 186
 187 /* Read block data, uncompressed and also store it in memory.  */
 188 /* XXX Investigate possibility of in-place decompression to reduce memory
 189  * footprint. Or try to uncompress directly to buf if possible.  */
 190 static int
 191 uncompress_block (struct grub_lzopio *lzopio)
 192 {
 193   lzo_uint usize = lzopio->block.usize;
 194
 195   if (read_block_data (lzopio) < 0)
 196     return -1;
 197
 198   /* Incompressible data. */
 199   if (lzopio->block.csize == lzopio->block.usize)
 200     {
 201       lzopio->block.udata = lzopio->block.cdata;
 202       lzopio->block.cdata = NULL;
 203     }
 204   else
 205     {
 206       lzopio->block.udata = grub_malloc (lzopio->block.usize);
 207       if (!lzopio->block.udata)
 208         return -1;
 209
 210       if (lzo1x_decompress_safe (lzopio->block.cdata, lzopio->block.csize,
 211                                  lzopio->block.udata, &usize, NULL)
 212           != LZO_E_OK)
 213         return -1;
 214
 215       if (lzopio->ucheck_fun)
 216         {
 217           grub_uint8_t computed_hash[GRUB_CRYPTO_MAX_MDLEN];
 218
 219           if (lzopio->ucheck_fun->mdlen > GRUB_CRYPTO_MAX_MDLEN)
 220             return -1;
 221
 222           grub_crypto_hash (lzopio->ucheck_fun, computed_hash,
 223                             lzopio->block.udata,
 224                             lzopio->block.usize);
 225
 226           if (grub_memcmp
 227               (computed_hash, &lzopio->block.ucheck,
 228                sizeof (lzopio->block.ucheck)) != 0)
 229             return -1;
 230         }
 231
 232       /* Compressed data can be free now.  */
 233       grub_free (lzopio->block.cdata);
 234       lzopio->block.cdata = NULL;
 235     }
 236
 237   return 0;
 238 }
 239
 240 /* Jump to next block and read its header.  */
 241 static int
 242 jump_block (struct grub_lzopio *lzopio)
 243 {
 244   /* only jump if block was not decompressed (and read from disk) */
 245   if (!lzopio->block.udata)
 246     {
 247       grub_off_t off = grub_file_tell (lzopio->file) + lzopio->block.csize;
 248
 249       if (grub_file_seek (lzopio->file, off) == ((grub_off_t) - 1))
 250         return -1;
 251     }
 252
 253   return read_block_header (lzopio);
 254 }
 255
 256 static int
 257 calculate_uncompressed_size (grub_file_t file)
 258 {
 259   grub_lzopio_t lzopio = file->data;
 260   grub_off_t usize_total = 0;
 261
 262   if (read_block_header (lzopio) < 0)
 263     return -1;
 264
 265   /* FIXME: Don't do this for not easily seekable files.  */
 266   while (lzopio->block.usize != 0)
 267     {
 268       usize_total += lzopio->block.usize;
 269
 270       if (jump_block (lzopio) < 0)
 271         return -1;
 272     }
 273
 274   file->size = usize_total;
 275
 276   return 0;
 277 }
 278
 279 struct lzop_header
 280 {
 281   grub_uint8_t magic[LZOP_MAGIC_SIZE];
 282   grub_uint16_t lzop_version;
 283   grub_uint16_t lib_version;
 284   grub_uint16_t lib_version_ext;
 285   grub_uint8_t method;
 286   grub_uint8_t level;
 287   grub_uint32_t flags;
 288   /* grub_uint32_t filter; */ /* No filters support. Rarely used anyway.  */
 289   grub_uint32_t mode;
 290   grub_uint32_t mtime_lo;
 291   grub_uint32_t mtime_hi;
 292   grub_uint8_t name_len;
 293 } GRUB_PACKED;
 294
 295 static int
 296 test_header (grub_file_t file)
 297 {
 298   grub_lzopio_t lzopio = file->data;
 299   struct lzop_header header;
 300   grub_uint32_t flags, checksum;
 301   const gcry_md_spec_t *hcheck;
 302   grub_uint8_t *context = NULL;
 303   grub_uint8_t *name = NULL;
 304
 305   if (grub_file_read (lzopio->file, &header, sizeof (header)) != sizeof (header))
 306     return 0;
 307
 308   if (grub_memcmp (header.magic, LZOP_MAGIC, LZOP_MAGIC_SIZE) != 0)
 309     return 0;
 310
 311   if (grub_be_to_cpu16(header.lib_version) < LZOP_NEW_LIB)
 312     return 0;
 313
 314   /* Too new version, should upgrade minilzo?  */
 315   if (grub_be_to_cpu16 (header.lib_version_ext) > MINILZO_VERSION)
 316     return 0;
 317
 318   flags = grub_be_to_cpu32 (header.flags);
 319
 320   if (flags & F_CRC32_D)
 321     {
 322       lzopio->has_ucheck = 1;
 323       lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("crc32");
 324     }
 325   else if (flags & F_ADLER32_D)
 326     {
 327       lzopio->has_ucheck = 1;
 328       lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("adler32");
 329     }
 330
 331   if (flags & F_CRC32_C)
 332     {
 333       lzopio->has_ccheck = 1;
 334       lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("crc32");
 335     }
 336   else if (flags & F_ADLER32_C)
 337     {
 338       lzopio->has_ccheck = 1;
 339       lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("adler32");
 340     }
 341
 342   if (flags & F_H_CRC32)
 343     hcheck = grub_crypto_lookup_md_by_name ("crc32");
 344   else
 345     hcheck = grub_crypto_lookup_md_by_name ("adler32");
 346
 347   if (hcheck) {
 348     context = grub_malloc(hcheck->contextsize);
 349     if (! context)
 350       return 0;
 351
 352     hcheck->init(context);
 353
 354     /* MAGIC is not included in check calculation.  */
 355     hcheck->write(context, &header.lzop_version, sizeof(header)- LZOP_MAGIC_SIZE);
 356   }
 357
 358   if (header.name_len != 0)
 359     {
 360       name = grub_malloc (header.name_len);
 361       if (! name)
 362         {
 363           grub_free (context);
 364           return 0;
 365         }
 366
 367       if (grub_file_read (lzopio->file, name, header.name_len) !=
 368           header.name_len)
 369         {
 370           grub_free(name);
 371           goto CORRUPTED;
 372         }
 373
 374       if (hcheck)
 375         hcheck->write(context, name, header.name_len);
 376
 377       grub_free(name);
 378     }
 379
 380   if (hcheck)
 381     hcheck->final(context);
 382
 383   if (grub_file_read (lzopio->file, &checksum, sizeof (checksum)) !=
 384       sizeof (checksum))
 385     goto CORRUPTED;
 386
 387   if (hcheck && grub_memcmp (&checksum, hcheck->read(context), sizeof(checksum)) != 0)
 388     goto CORRUPTED;
 389
 390   lzopio->start_block_off = grub_file_tell (lzopio->file);
 391
 392   if (calculate_uncompressed_size (file) < 0)
 393     goto CORRUPTED;
 394
 395   /* Get back to start block.  */
 396   grub_file_seek (lzopio->file, lzopio->start_block_off);
 397
 398   /* Read first block - grub_lzopio_read() expects valid block.  */
 399   if (read_block_header (lzopio) < 0)
 400     goto CORRUPTED;
 401
 402   lzopio->saved_off = 0;
 403   return 1;
 404
 405 CORRUPTED:
 406   return 0;
 407 }
 408
 409 static grub_file_t
 410 grub_lzopio_open (grub_file_t io,
 411                   const char *name __attribute__ ((unused)))
 412 {
 413   grub_file_t file;
 414   grub_lzopio_t lzopio;
 415
 416   file = (grub_file_t) grub_zalloc (sizeof (*file));
 417   if (!file)
 418     return 0;
 419
 420   lzopio = grub_zalloc (sizeof (*lzopio));
 421   if (!lzopio)
 422     {
 423       grub_free (file);
 424       return 0;
 425     }
 426
 427   lzopio->file = io;
 428
 429   file->device = io->device;
 430   file->data = lzopio;
 431   file->fs = &grub_lzopio_fs;
 432   file->size = GRUB_FILE_SIZE_UNKNOWN;
 433   file->not_easily_seekable = 1;
 434
 435   if (grub_file_tell (lzopio->file) != 0)
 436     grub_file_seek (lzopio->file, 0);
 437
 438   if (!test_header (file))
 439     {
 440       grub_errno = GRUB_ERR_NONE;
 441       grub_file_seek (io, 0);
 442       grub_free (lzopio);
 443       grub_free (file);
 444
 445       return io;
 446     }
 447
 448   return file;
 449 }
 450
 451 static grub_ssize_t
 452 grub_lzopio_read (grub_file_t file, char *buf, grub_size_t len)
 453 {
 454   grub_lzopio_t lzopio = file->data;
 455   grub_ssize_t ret = 0;
 456   grub_off_t off;
 457
 458   /* Backward seek before last read block.  */
 459   if (lzopio->saved_off > grub_file_tell (file))
 460     {
 461       grub_file_seek (lzopio->file, lzopio->start_block_off);
 462
 463       if (read_block_header (lzopio) < 0)
 464         goto CORRUPTED;
 465
 466       lzopio->saved_off = 0;
 467     }
 468
 469   /* Forward to first block with requested data.  */
 470   while (lzopio->saved_off + lzopio->block.usize <= grub_file_tell (file))
 471     {
 472       /* EOF, could be possible files with unknown size.  */
 473       if (lzopio->block.usize == 0)
 474         return 0;
 475
 476       if (jump_block (lzopio) < 0)
 477         goto CORRUPTED;
 478     }
 479
 480   off = grub_file_tell (file) - lzopio->saved_off;
 481
 482   while (len != 0 && lzopio->block.usize != 0)
 483     {
 484       grub_size_t to_copy;
 485
 486       /* Block not decompressed yet.  */
 487       if (!lzopio->block.udata && uncompress_block (lzopio) < 0)
 488         goto CORRUPTED;
 489
 490       /* Copy requested data into buffer.  */
 491       to_copy = lzopio->block.usize - off;
 492       if (to_copy > len)
 493         to_copy = len;
 494       grub_memcpy (buf, lzopio->block.udata + off, to_copy);
 495
 496       len -= to_copy;
 497       buf += to_copy;
 498       ret += to_copy;
 499       off = 0;
 500
 501       /* Read next block if needed.  */
 502       if (len > 0 && read_block_header (lzopio) < 0)
 503         goto CORRUPTED;
 504     }
 505
 506   return ret;
 507
 508 CORRUPTED:
 509   grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, N_("lzop file corrupted"));
 510   return -1;
 511 }
 512
 513 /* Release everything, including the underlying file object.  */
 514 static grub_err_t
 515 grub_lzopio_close (grub_file_t file)
 516 {
 517   grub_lzopio_t lzopio = file->data;
 518
 519   grub_file_close (lzopio->file);
 520   grub_free (lzopio->block.cdata);
 521   grub_free (lzopio->block.udata);
 522   grub_free (lzopio);
 523
 524   /* Device must not be closed twice.  */
 525   file->device = 0;
 526   file->name = 0;
 527   return grub_errno;
 528 }
 529
 530 static struct grub_fs grub_lzopio_fs = {
 531   .name = "lzopio",
 532   .dir = 0,
 533   .open = 0,
 534   .read = grub_lzopio_read,
 535   .close = grub_lzopio_close,
 536   .label = 0,
 537   .next = 0
 538 };
 539
 540 GRUB_MOD_INIT (lzopio)
 541 {
 542   grub_file_filter_register (GRUB_FILE_FILTER_LZOPIO, grub_lzopio_open);
 543 }
 544
 545 GRUB_MOD_FINI (lzopio)
 546 {
 547   grub_file_filter_unregister (GRUB_FILE_FILTER_LZOPIO);
 548 }