contrib/libarchive/libarchive/archive_read_support_filter_gzip.c

   1 /*-
   2  * Copyright (c) 2003-2007 Tim Kientzle
   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("$FreeBSD$");
  29
  30
  31 #ifdef HAVE_ERRNO_H
  32 #include <errno.h>
  33 #endif
  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_LIMITS_H
  41 #include <limits.h>
  42 #endif
  43 #ifdef HAVE_UNISTD_H
  44 #include <unistd.h>
  45 #endif
  46 #ifdef HAVE_ZLIB_H
  47 #include <zlib.h>
  48 #endif
  49
  50 #include "archive.h"
  51 #include "archive_entry.h"
  52 #include "archive_endian.h"
  53 #include "archive_private.h"
  54 #include "archive_read_private.h"
  55
  56 #ifdef HAVE_ZLIB_H
  57 struct private_data {
  58         z_stream         stream;
  59         char             in_stream;
  60         unsigned char   *out_block;
  61         size_t           out_block_size;
  62         int64_t          total_out;
  63         unsigned long    crc;
  64         uint32_t         mtime;
  65         char            *name;
  66         char             eof; /* True = found end of compressed data. */
  67 };
  68
  69 /* Gzip Filter. */
  70 static ssize_t  gzip_filter_read(struct archive_read_filter *, const void **);
  71 static int      gzip_filter_close(struct archive_read_filter *);
  72 #endif
  73
  74 /*
  75  * Note that we can detect gzip archives even if we can't decompress
  76  * them.  (In fact, we like detecting them because we can give better
  77  * error messages.)  So the bid framework here gets compiled even
  78  * if zlib is unavailable.
  79  *
  80  * TODO: If zlib is unavailable, gzip_bidder_init() should
  81  * use the compress_program framework to try to fire up an external
  82  * gzip program.
  83  */
  84 static int      gzip_bidder_bid(struct archive_read_filter_bidder *,
  85                     struct archive_read_filter *);
  86 static int      gzip_bidder_init(struct archive_read_filter *);
  87
  88 #if ARCHIVE_VERSION_NUMBER < 4000000
  89 /* Deprecated; remove in libarchive 4.0 */
  90 int
  91 archive_read_support_compression_gzip(struct archive *a)
  92 {
  93         return archive_read_support_filter_gzip(a);
  94 }
  95 #endif
  96
  97 int
  98 archive_read_support_filter_gzip(struct archive *_a)
  99 {
 100         struct archive_read *a = (struct archive_read *)_a;
 101         struct archive_read_filter_bidder *bidder;
 102
 103         archive_check_magic(_a, ARCHIVE_READ_MAGIC,
 104             ARCHIVE_STATE_NEW, "archive_read_support_filter_gzip");
 105
 106         if (__archive_read_get_bidder(a, &bidder) != ARCHIVE_OK)
 107                 return (ARCHIVE_FATAL);
 108
 109         bidder->data = NULL;
 110         bidder->name = "gzip";
 111         bidder->bid = gzip_bidder_bid;
 112         bidder->init = gzip_bidder_init;
 113         bidder->options = NULL;
 114         bidder->free = NULL; /* No data, so no cleanup necessary. */
 115         /* Signal the extent of gzip support with the return value here. */
 116 #if HAVE_ZLIB_H
 117         return (ARCHIVE_OK);
 118 #else
 119         archive_set_error(_a, ARCHIVE_ERRNO_MISC,
 120             "Using external gzip program");
 121         return (ARCHIVE_WARN);
 122 #endif
 123 }
 124
 125 /*
 126  * Read and verify the header.
 127  *
 128  * Returns zero if the header couldn't be validated, else returns
 129  * number of bytes in header.  If pbits is non-NULL, it receives a
 130  * count of bits verified, suitable for use by bidder.
 131  */
 132 static ssize_t
 133 peek_at_header(struct archive_read_filter *filter, int *pbits,
 134                struct private_data *state)
 135 {
 136         const unsigned char *p;
 137         ssize_t avail, len;
 138         int bits = 0;
 139         int header_flags;
 140
 141         /* Start by looking at the first ten bytes of the header, which
 142          * is all fixed layout. */
 143         len = 10;
 144         p = __archive_read_filter_ahead(filter, len, &avail);
 145         if (p == NULL || avail == 0)
 146                 return (0);
 147         /* We only support deflation- third byte must be 0x08. */
 148         if (memcmp(p, "\x1F\x8B\x08", 3) != 0)
 149                 return (0);
 150         bits += 24;
 151         if ((p[3] & 0xE0)!= 0)  /* No reserved flags set. */
 152                 return (0);
 153         bits += 3;
 154         header_flags = p[3];
 155         /* Bytes 4-7 are mod time in little endian. */
 156         if (state)
 157                 state->mtime = archive_le32dec(p + 4);
 158         /* Byte 8 is deflate flags. */
 159         /* XXXX TODO: return deflate flags back to consume_header for use
 160            in initializing the decompressor. */
 161         /* Byte 9 is OS. */
 162
 163         /* Optional extra data:  2 byte length plus variable body. */
 164         if (header_flags & 4) {
 165                 p = __archive_read_filter_ahead(filter, len + 2, &avail);
 166                 if (p == NULL)
 167                         return (0);
 168                 len += ((int)p[len + 1] << 8) | (int)p[len];
 169                 len += 2;
 170         }
 171
 172         /* Null-terminated optional filename. */
 173         if (header_flags & 8) {
 174                 ssize_t file_start = len;
 175                 do {
 176                         ++len;
 177                         if (avail < len)
 178                                 p = __archive_read_filter_ahead(filter,
 179                                     len, &avail);
 180                         if (p == NULL)
 181                                 return (0);
 182                 } while (p[len - 1] != 0);
 183
 184                 if (state) {
 185                         /* Reset the name in case of repeat header reads. */
 186                         free(state->name);
 187                         state->name = strdup((const char *)&p[file_start]);
 188                 }
 189         }
 190
 191         /* Null-terminated optional comment. */
 192         if (header_flags & 16) {
 193                 do {
 194                         ++len;
 195                         if (avail < len)
 196                                 p = __archive_read_filter_ahead(filter,
 197                                     len, &avail);
 198                         if (p == NULL)
 199                                 return (0);
 200                 } while (p[len - 1] != 0);
 201         }
 202
 203         /* Optional header CRC */
 204         if ((header_flags & 2)) {
 205                 p = __archive_read_filter_ahead(filter, len + 2, &avail);
 206                 if (p == NULL)
 207                         return (0);
 208 #if 0
 209         int hcrc = ((int)p[len + 1] << 8) | (int)p[len];
 210         int crc = /* XXX TODO: Compute header CRC. */;
 211         if (crc != hcrc)
 212                 return (0);
 213         bits += 16;
 214 #endif
 215                 len += 2;
 216         }
 217
 218         if (pbits != NULL)
 219                 *pbits = bits;
 220         return (len);
 221 }
 222
 223 /*
 224  * Bidder just verifies the header and returns the number of verified bits.
 225  */
 226 static int
 227 gzip_bidder_bid(struct archive_read_filter_bidder *self,
 228     struct archive_read_filter *filter)
 229 {
 230         int bits_checked;
 231
 232         (void)self; /* UNUSED */
 233
 234         if (peek_at_header(filter, &bits_checked, NULL))
 235                 return (bits_checked);
 236         return (0);
 237 }
 238
 239 static int
 240 gzip_read_header(struct archive_read_filter *self, struct archive_entry *entry)
 241 {
 242         struct private_data *state;
 243
 244         state = (struct private_data *)self->data;
 245
 246         /* A mtime of 0 is considered invalid/missing. */
 247         if (state->mtime != 0)
 248                 archive_entry_set_mtime(entry, state->mtime, 0);
 249
 250         /* If the name is available, extract it. */
 251         if (state->name)
 252                 archive_entry_set_pathname(entry, state->name);
 253
 254         return (ARCHIVE_OK);
 255 }
 256
 257 #ifndef HAVE_ZLIB_H
 258
 259 /*
 260  * If we don't have the library on this system, we can't do the
 261  * decompression directly.  We can, however, try to run "gzip -d"
 262  * in case that's available.
 263  */
 264 static int
 265 gzip_bidder_init(struct archive_read_filter *self)
 266 {
 267         int r;
 268
 269         r = __archive_read_program(self, "gzip -d");
 270         /* Note: We set the format here even if __archive_read_program()
 271          * above fails.  We do, after all, know what the format is
 272          * even if we weren't able to read it. */
 273         self->code = ARCHIVE_FILTER_GZIP;
 274         self->name = "gzip";
 275         return (r);
 276 }
 277
 278 #else
 279
 280 /*
 281  * Initialize the filter object.
 282  */
 283 static int
 284 gzip_bidder_init(struct archive_read_filter *self)
 285 {
 286         struct private_data *state;
 287         static const size_t out_block_size = 64 * 1024;
 288         void *out_block;
 289
 290         self->code = ARCHIVE_FILTER_GZIP;
 291         self->name = "gzip";
 292
 293         state = (struct private_data *)calloc(sizeof(*state), 1);
 294         out_block = (unsigned char *)malloc(out_block_size);
 295         if (state == NULL || out_block == NULL) {
 296                 free(out_block);
 297                 free(state);
 298                 archive_set_error(&self->archive->archive, ENOMEM,
 299                     "Can't allocate data for gzip decompression");
 300                 return (ARCHIVE_FATAL);
 301         }
 302
 303         self->data = state;
 304         state->out_block_size = out_block_size;
 305         state->out_block = out_block;
 306         self->read = gzip_filter_read;
 307         self->skip = NULL; /* not supported */
 308         self->close = gzip_filter_close;
 309         self->read_header = gzip_read_header;
 310
 311         state->in_stream = 0; /* We're not actually within a stream yet. */
 312
 313         return (ARCHIVE_OK);
 314 }
 315
 316 static int
 317 consume_header(struct archive_read_filter *self)
 318 {
 319         struct private_data *state;
 320         ssize_t avail;
 321         size_t len;
 322         int ret;
 323
 324         state = (struct private_data *)self->data;
 325
 326         /* If this is a real header, consume it. */
 327         len = peek_at_header(self->upstream, NULL, state);
 328         if (len == 0)
 329                 return (ARCHIVE_EOF);
 330         __archive_read_filter_consume(self->upstream, len);
 331
 332         /* Initialize CRC accumulator. */
 333         state->crc = crc32(0L, NULL, 0);
 334
 335         /* Initialize compression library. */
 336         state->stream.next_in = (unsigned char *)(uintptr_t)
 337             __archive_read_filter_ahead(self->upstream, 1, &avail);
 338         state->stream.avail_in = (uInt)avail;
 339         ret = inflateInit2(&(state->stream),
 340             -15 /* Don't check for zlib header */);
 341
 342         /* Decipher the error code. */
 343         switch (ret) {
 344         case Z_OK:
 345                 state->in_stream = 1;
 346                 return (ARCHIVE_OK);
 347         case Z_STREAM_ERROR:
 348                 archive_set_error(&self->archive->archive,
 349                     ARCHIVE_ERRNO_MISC,
 350                     "Internal error initializing compression library: "
 351                     "invalid setup parameter");
 352                 break;
 353         case Z_MEM_ERROR:
 354                 archive_set_error(&self->archive->archive, ENOMEM,
 355                     "Internal error initializing compression library: "
 356                     "out of memory");
 357                 break;
 358         case Z_VERSION_ERROR:
 359                 archive_set_error(&self->archive->archive,
 360                     ARCHIVE_ERRNO_MISC,
 361                     "Internal error initializing compression library: "
 362                     "invalid library version");
 363                 break;
 364         default:
 365                 archive_set_error(&self->archive->archive,
 366                     ARCHIVE_ERRNO_MISC,
 367                     "Internal error initializing compression library: "
 368                     " Zlib error %d", ret);
 369                 break;
 370         }
 371         return (ARCHIVE_FATAL);
 372 }
 373
 374 static int
 375 consume_trailer(struct archive_read_filter *self)
 376 {
 377         struct private_data *state;
 378         const unsigned char *p;
 379         ssize_t avail;
 380
 381         state = (struct private_data *)self->data;
 382
 383         state->in_stream = 0;
 384         switch (inflateEnd(&(state->stream))) {
 385         case Z_OK:
 386                 break;
 387         default:
 388                 archive_set_error(&self->archive->archive,
 389                     ARCHIVE_ERRNO_MISC,
 390                     "Failed to clean up gzip decompressor");
 391                 return (ARCHIVE_FATAL);
 392         }
 393
 394         /* GZip trailer is a fixed 8 byte structure. */
 395         p = __archive_read_filter_ahead(self->upstream, 8, &avail);
 396         if (p == NULL || avail == 0)
 397                 return (ARCHIVE_FATAL);
 398
 399         /* XXX TODO: Verify the length and CRC. */
 400
 401         /* We've verified the trailer, so consume it now. */
 402         __archive_read_filter_consume(self->upstream, 8);
 403
 404         return (ARCHIVE_OK);
 405 }
 406
 407 static ssize_t
 408 gzip_filter_read(struct archive_read_filter *self, const void **p)
 409 {
 410         struct private_data *state;
 411         size_t decompressed;
 412         ssize_t avail_in, max_in;
 413         int ret;
 414
 415         state = (struct private_data *)self->data;
 416
 417         /* Empty our output buffer. */
 418         state->stream.next_out = state->out_block;
 419         state->stream.avail_out = (uInt)state->out_block_size;
 420
 421         /* Try to fill the output buffer. */
 422         while (state->stream.avail_out > 0 && !state->eof) {
 423                 /* If we're not in a stream, read a header
 424                  * and initialize the decompression library. */
 425                 if (!state->in_stream) {
 426                         ret = consume_header(self);
 427                         if (ret == ARCHIVE_EOF) {
 428                                 state->eof = 1;
 429                                 break;
 430                         }
 431                         if (ret < ARCHIVE_OK)
 432                                 return (ret);
 433                 }
 434
 435                 /* Peek at the next available data. */
 436                 /* ZLib treats stream.next_in as const but doesn't declare
 437                  * it so, hence this ugly cast. */
 438                 state->stream.next_in = (unsigned char *)(uintptr_t)
 439                     __archive_read_filter_ahead(self->upstream, 1, &avail_in);
 440                 if (state->stream.next_in == NULL) {
 441                         archive_set_error(&self->archive->archive,
 442                             ARCHIVE_ERRNO_MISC,
 443                             "truncated gzip input");
 444                         return (ARCHIVE_FATAL);
 445                 }
 446                 if (UINT_MAX >= SSIZE_MAX)
 447                         max_in = SSIZE_MAX;
 448                 else
 449                         max_in = UINT_MAX;
 450                 if (avail_in > max_in)
 451                         avail_in = max_in;
 452                 state->stream.avail_in = (uInt)avail_in;
 453
 454                 /* Decompress and consume some of that data. */
 455                 ret = inflate(&(state->stream), 0);
 456                 switch (ret) {
 457                 case Z_OK: /* Decompressor made some progress. */
 458                         __archive_read_filter_consume(self->upstream,
 459                             avail_in - state->stream.avail_in);
 460                         break;
 461                 case Z_STREAM_END: /* Found end of stream. */
 462                         __archive_read_filter_consume(self->upstream,
 463                             avail_in - state->stream.avail_in);
 464                         /* Consume the stream trailer; release the
 465                          * decompression library. */
 466                         ret = consume_trailer(self);
 467                         if (ret < ARCHIVE_OK)
 468                                 return (ret);
 469                         break;
 470                 default:
 471                         /* Return an error. */
 472                         archive_set_error(&self->archive->archive,
 473                             ARCHIVE_ERRNO_MISC,
 474                             "gzip decompression failed");
 475                         return (ARCHIVE_FATAL);
 476                 }
 477         }
 478
 479         /* We've read as much as we can. */
 480         decompressed = state->stream.next_out - state->out_block;
 481         state->total_out += decompressed;
 482         if (decompressed == 0)
 483                 *p = NULL;
 484         else
 485                 *p = state->out_block;
 486         return (decompressed);
 487 }
 488
 489 /*
 490  * Clean up the decompressor.
 491  */
 492 static int
 493 gzip_filter_close(struct archive_read_filter *self)
 494 {
 495         struct private_data *state;
 496         int ret;
 497
 498         state = (struct private_data *)self->data;
 499         ret = ARCHIVE_OK;
 500
 501         if (state->in_stream) {
 502                 switch (inflateEnd(&(state->stream))) {
 503                 case Z_OK:
 504                         break;
 505                 default:
 506                         archive_set_error(&(self->archive->archive),
 507                             ARCHIVE_ERRNO_MISC,
 508                             "Failed to clean up gzip compressor");
 509                         ret = ARCHIVE_FATAL;
 510                 }
 511         }
 512
 513         free(state->name);
 514         free(state->out_block);
 515         free(state);
 516         return (ret);
 517 }
 518
 519 #endif /* HAVE_ZLIB_H */