| 1 | /* Compressed section support (intended for debug sections). |
| 2 | Copyright (C) 2008-2014 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of BFD, the Binary File Descriptor library. |
| 5 | |
| 6 | This program 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 | This program 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 this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 19 | MA 02110-1301, USA. */ |
| 20 | |
| 21 | #include "sysdep.h" |
| 22 | #include "bfd.h" |
| 23 | #include "libbfd.h" |
| 24 | #ifdef HAVE_ZLIB_H |
| 25 | #include <zlib.h> |
| 26 | #endif |
| 27 | #include "safe-ctype.h" |
| 28 | |
| 29 | #ifdef HAVE_ZLIB_H |
| 30 | static bfd_boolean |
| 31 | decompress_contents (bfd_byte *compressed_buffer, |
| 32 | bfd_size_type compressed_size, |
| 33 | bfd_byte *uncompressed_buffer, |
| 34 | bfd_size_type uncompressed_size) |
| 35 | { |
| 36 | z_stream strm; |
| 37 | int rc; |
| 38 | |
| 39 | /* It is possible the section consists of several compressed |
| 40 | buffers concatenated together, so we uncompress in a loop. */ |
| 41 | strm.zalloc = NULL; |
| 42 | strm.zfree = NULL; |
| 43 | strm.opaque = NULL; |
| 44 | strm.avail_in = compressed_size - 12; |
| 45 | strm.next_in = (Bytef*) compressed_buffer + 12; |
| 46 | strm.avail_out = uncompressed_size; |
| 47 | |
| 48 | BFD_ASSERT (Z_OK == 0); |
| 49 | rc = inflateInit (&strm); |
| 50 | while (strm.avail_in > 0 && strm.avail_out > 0) |
| 51 | { |
| 52 | if (rc != Z_OK) |
| 53 | break; |
| 54 | strm.next_out = ((Bytef*) uncompressed_buffer |
| 55 | + (uncompressed_size - strm.avail_out)); |
| 56 | rc = inflate (&strm, Z_FINISH); |
| 57 | if (rc != Z_STREAM_END) |
| 58 | break; |
| 59 | rc = inflateReset (&strm); |
| 60 | } |
| 61 | rc |= inflateEnd (&strm); |
| 62 | return rc == Z_OK && strm.avail_out == 0; |
| 63 | } |
| 64 | #endif |
| 65 | |
| 66 | /* |
| 67 | FUNCTION |
| 68 | bfd_compress_section_contents |
| 69 | |
| 70 | SYNOPSIS |
| 71 | bfd_boolean bfd_compress_section_contents |
| 72 | (bfd *abfd, asection *section, bfd_byte *uncompressed_buffer, |
| 73 | bfd_size_type uncompressed_size); |
| 74 | |
| 75 | DESCRIPTION |
| 76 | |
| 77 | Compress data of the size specified in @var{uncompressed_size} |
| 78 | and pointed to by @var{uncompressed_buffer} using zlib and store |
| 79 | as the contents field. This function assumes the contents |
| 80 | field was allocated using bfd_malloc() or equivalent. If zlib |
| 81 | is not installed on this machine, the input is unmodified. |
| 82 | |
| 83 | Return @code{TRUE} if the full section contents is compressed |
| 84 | successfully. |
| 85 | */ |
| 86 | |
| 87 | bfd_boolean |
| 88 | bfd_compress_section_contents (bfd *abfd ATTRIBUTE_UNUSED, |
| 89 | sec_ptr sec ATTRIBUTE_UNUSED, |
| 90 | bfd_byte *uncompressed_buffer ATTRIBUTE_UNUSED, |
| 91 | bfd_size_type uncompressed_size ATTRIBUTE_UNUSED) |
| 92 | { |
| 93 | #ifndef HAVE_ZLIB_H |
| 94 | bfd_set_error (bfd_error_invalid_operation); |
| 95 | return FALSE; |
| 96 | #else |
| 97 | uLong compressed_size; |
| 98 | bfd_byte *compressed_buffer; |
| 99 | |
| 100 | compressed_size = compressBound (uncompressed_size) + 12; |
| 101 | compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size); |
| 102 | |
| 103 | if (compressed_buffer == NULL) |
| 104 | return FALSE; |
| 105 | |
| 106 | if (compress ((Bytef*) compressed_buffer + 12, |
| 107 | &compressed_size, |
| 108 | (const Bytef*) uncompressed_buffer, |
| 109 | uncompressed_size) != Z_OK) |
| 110 | { |
| 111 | free (compressed_buffer); |
| 112 | bfd_set_error (bfd_error_bad_value); |
| 113 | return FALSE; |
| 114 | } |
| 115 | |
| 116 | /* Write the zlib header. In this case, it should be "ZLIB" followed |
| 117 | by the uncompressed section size, 8 bytes in big-endian order. */ |
| 118 | memcpy (compressed_buffer, "ZLIB", 4); |
| 119 | compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8; |
| 120 | compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8; |
| 121 | compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8; |
| 122 | compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8; |
| 123 | compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8; |
| 124 | compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8; |
| 125 | compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8; |
| 126 | compressed_buffer[4] = uncompressed_size; |
| 127 | compressed_size += 12; |
| 128 | |
| 129 | /* Free the uncompressed contents if we compress in place. */ |
| 130 | if (uncompressed_buffer == sec->contents) |
| 131 | free (uncompressed_buffer); |
| 132 | |
| 133 | sec->contents = compressed_buffer; |
| 134 | sec->size = compressed_size; |
| 135 | sec->compress_status = COMPRESS_SECTION_DONE; |
| 136 | |
| 137 | return TRUE; |
| 138 | #endif /* HAVE_ZLIB_H */ |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | FUNCTION |
| 143 | bfd_get_full_section_contents |
| 144 | |
| 145 | SYNOPSIS |
| 146 | bfd_boolean bfd_get_full_section_contents |
| 147 | (bfd *abfd, asection *section, bfd_byte **ptr); |
| 148 | |
| 149 | DESCRIPTION |
| 150 | Read all data from @var{section} in BFD @var{abfd}, decompress |
| 151 | if needed, and store in @var{*ptr}. If @var{*ptr} is NULL, |
| 152 | return @var{*ptr} with memory malloc'd by this function. |
| 153 | |
| 154 | Return @code{TRUE} if the full section contents is retrieved |
| 155 | successfully. |
| 156 | */ |
| 157 | |
| 158 | bfd_boolean |
| 159 | bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr) |
| 160 | { |
| 161 | bfd_size_type sz; |
| 162 | bfd_byte *p = *ptr; |
| 163 | #ifdef HAVE_ZLIB_H |
| 164 | bfd_boolean ret; |
| 165 | bfd_size_type save_size; |
| 166 | bfd_size_type save_rawsize; |
| 167 | bfd_byte *compressed_buffer; |
| 168 | #endif |
| 169 | |
| 170 | if (abfd->direction != write_direction && sec->rawsize != 0) |
| 171 | sz = sec->rawsize; |
| 172 | else |
| 173 | sz = sec->size; |
| 174 | if (sz == 0) |
| 175 | return TRUE; |
| 176 | |
| 177 | switch (sec->compress_status) |
| 178 | { |
| 179 | case COMPRESS_SECTION_NONE: |
| 180 | if (p == NULL) |
| 181 | { |
| 182 | p = (bfd_byte *) bfd_malloc (sz); |
| 183 | if (p == NULL) |
| 184 | return FALSE; |
| 185 | } |
| 186 | if (!bfd_get_section_contents (abfd, sec, p, 0, sz)) |
| 187 | { |
| 188 | if (*ptr != p) |
| 189 | free (p); |
| 190 | return FALSE; |
| 191 | } |
| 192 | *ptr = p; |
| 193 | return TRUE; |
| 194 | |
| 195 | case DECOMPRESS_SECTION_SIZED: |
| 196 | #ifndef HAVE_ZLIB_H |
| 197 | bfd_set_error (bfd_error_invalid_operation); |
| 198 | return FALSE; |
| 199 | #else |
| 200 | /* Read in the full compressed section contents. */ |
| 201 | compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size); |
| 202 | if (compressed_buffer == NULL) |
| 203 | return FALSE; |
| 204 | save_rawsize = sec->rawsize; |
| 205 | save_size = sec->size; |
| 206 | /* Clear rawsize, set size to compressed size and set compress_status |
| 207 | to COMPRESS_SECTION_NONE. If the compressed size is bigger than |
| 208 | the uncompressed size, bfd_get_section_contents will fail. */ |
| 209 | sec->rawsize = 0; |
| 210 | sec->size = sec->compressed_size; |
| 211 | sec->compress_status = COMPRESS_SECTION_NONE; |
| 212 | ret = bfd_get_section_contents (abfd, sec, compressed_buffer, |
| 213 | 0, sec->compressed_size); |
| 214 | /* Restore rawsize and size. */ |
| 215 | sec->rawsize = save_rawsize; |
| 216 | sec->size = save_size; |
| 217 | sec->compress_status = DECOMPRESS_SECTION_SIZED; |
| 218 | if (!ret) |
| 219 | goto fail_compressed; |
| 220 | |
| 221 | if (p == NULL) |
| 222 | p = (bfd_byte *) bfd_malloc (sz); |
| 223 | if (p == NULL) |
| 224 | goto fail_compressed; |
| 225 | |
| 226 | if (!decompress_contents (compressed_buffer, sec->compressed_size, p, sz)) |
| 227 | { |
| 228 | bfd_set_error (bfd_error_bad_value); |
| 229 | if (p != *ptr) |
| 230 | free (p); |
| 231 | fail_compressed: |
| 232 | free (compressed_buffer); |
| 233 | return FALSE; |
| 234 | } |
| 235 | |
| 236 | free (compressed_buffer); |
| 237 | *ptr = p; |
| 238 | return TRUE; |
| 239 | #endif |
| 240 | |
| 241 | case COMPRESS_SECTION_DONE: |
| 242 | if (p == NULL) |
| 243 | { |
| 244 | p = (bfd_byte *) bfd_malloc (sz); |
| 245 | if (p == NULL) |
| 246 | return FALSE; |
| 247 | *ptr = p; |
| 248 | } |
| 249 | memcpy (p, sec->contents, sz); |
| 250 | return TRUE; |
| 251 | |
| 252 | default: |
| 253 | abort (); |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | /* |
| 258 | FUNCTION |
| 259 | bfd_cache_section_contents |
| 260 | |
| 261 | SYNOPSIS |
| 262 | void bfd_cache_section_contents |
| 263 | (asection *sec, void *contents); |
| 264 | |
| 265 | DESCRIPTION |
| 266 | Stash @var(contents) so any following reads of @var(sec) do |
| 267 | not need to decompress again. |
| 268 | */ |
| 269 | |
| 270 | void |
| 271 | bfd_cache_section_contents (asection *sec, void *contents) |
| 272 | { |
| 273 | if (sec->compress_status == DECOMPRESS_SECTION_SIZED) |
| 274 | sec->compress_status = COMPRESS_SECTION_DONE; |
| 275 | sec->contents = contents; |
| 276 | sec->flags |= SEC_IN_MEMORY; |
| 277 | } |
| 278 | |
| 279 | |
| 280 | /* |
| 281 | FUNCTION |
| 282 | bfd_is_section_compressed |
| 283 | |
| 284 | SYNOPSIS |
| 285 | bfd_boolean bfd_is_section_compressed |
| 286 | (bfd *abfd, asection *section); |
| 287 | |
| 288 | DESCRIPTION |
| 289 | Return @code{TRUE} if @var{section} is compressed. |
| 290 | */ |
| 291 | |
| 292 | bfd_boolean |
| 293 | bfd_is_section_compressed (bfd *abfd, sec_ptr sec) |
| 294 | { |
| 295 | bfd_byte compressed_buffer [12]; |
| 296 | unsigned int saved = sec->compress_status; |
| 297 | bfd_boolean compressed; |
| 298 | |
| 299 | /* Don't decompress the section. */ |
| 300 | sec->compress_status = COMPRESS_SECTION_NONE; |
| 301 | |
| 302 | /* Read the zlib header. In this case, it should be "ZLIB" followed |
| 303 | by the uncompressed section size, 8 bytes in big-endian order. */ |
| 304 | compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12) |
| 305 | && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")); |
| 306 | |
| 307 | /* Check for the pathalogical case of a debug string section that |
| 308 | contains the string ZLIB.... as the first entry. We assume that |
| 309 | no uncompressed .debug_str section would ever be big enough to |
| 310 | have the first byte of its (big-endian) size be non-zero. */ |
| 311 | if (compressed |
| 312 | && strcmp (sec->name, ".debug_str") == 0 |
| 313 | && ISPRINT (compressed_buffer[4])) |
| 314 | compressed = FALSE; |
| 315 | |
| 316 | /* Restore compress_status. */ |
| 317 | sec->compress_status = saved; |
| 318 | return compressed; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | FUNCTION |
| 323 | bfd_init_section_decompress_status |
| 324 | |
| 325 | SYNOPSIS |
| 326 | bfd_boolean bfd_init_section_decompress_status |
| 327 | (bfd *abfd, asection *section); |
| 328 | |
| 329 | DESCRIPTION |
| 330 | Record compressed section size, update section size with |
| 331 | decompressed size and set compress_status to |
| 332 | DECOMPRESS_SECTION_SIZED. |
| 333 | |
| 334 | Return @code{FALSE} if the section is not a valid compressed |
| 335 | section or zlib is not installed on this machine. Otherwise, |
| 336 | return @code{TRUE}. |
| 337 | */ |
| 338 | |
| 339 | bfd_boolean |
| 340 | bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, |
| 341 | sec_ptr sec ATTRIBUTE_UNUSED) |
| 342 | { |
| 343 | #ifndef HAVE_ZLIB_H |
| 344 | bfd_set_error (bfd_error_invalid_operation); |
| 345 | return FALSE; |
| 346 | #else |
| 347 | bfd_byte compressed_buffer [12]; |
| 348 | bfd_size_type uncompressed_size; |
| 349 | |
| 350 | if (sec->rawsize != 0 |
| 351 | || sec->contents != NULL |
| 352 | || sec->compress_status != COMPRESS_SECTION_NONE |
| 353 | || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) |
| 354 | { |
| 355 | bfd_set_error (bfd_error_invalid_operation); |
| 356 | return FALSE; |
| 357 | } |
| 358 | |
| 359 | /* Read the zlib header. In this case, it should be "ZLIB" followed |
| 360 | by the uncompressed section size, 8 bytes in big-endian order. */ |
| 361 | if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")) |
| 362 | { |
| 363 | bfd_set_error (bfd_error_wrong_format); |
| 364 | return FALSE; |
| 365 | } |
| 366 | |
| 367 | uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; |
| 368 | uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; |
| 369 | uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; |
| 370 | uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; |
| 371 | uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; |
| 372 | uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; |
| 373 | uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; |
| 374 | uncompressed_size += compressed_buffer[11]; |
| 375 | |
| 376 | sec->compressed_size = sec->size; |
| 377 | sec->size = uncompressed_size; |
| 378 | sec->compress_status = DECOMPRESS_SECTION_SIZED; |
| 379 | |
| 380 | return TRUE; |
| 381 | #endif |
| 382 | } |
| 383 | |
| 384 | /* |
| 385 | FUNCTION |
| 386 | bfd_init_section_compress_status |
| 387 | |
| 388 | SYNOPSIS |
| 389 | bfd_boolean bfd_init_section_compress_status |
| 390 | (bfd *abfd, asection *section); |
| 391 | |
| 392 | DESCRIPTION |
| 393 | If open for read, compress section, update section size with |
| 394 | compressed size and set compress_status to COMPRESS_SECTION_DONE. |
| 395 | |
| 396 | Return @code{FALSE} if the section is not a valid compressed |
| 397 | section or zlib is not installed on this machine. Otherwise, |
| 398 | return @code{TRUE}. |
| 399 | */ |
| 400 | |
| 401 | bfd_boolean |
| 402 | bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, |
| 403 | sec_ptr sec ATTRIBUTE_UNUSED) |
| 404 | { |
| 405 | #ifndef HAVE_ZLIB_H |
| 406 | bfd_set_error (bfd_error_invalid_operation); |
| 407 | return FALSE; |
| 408 | #else |
| 409 | bfd_size_type uncompressed_size; |
| 410 | bfd_byte *uncompressed_buffer; |
| 411 | bfd_boolean ret; |
| 412 | |
| 413 | /* Error if not opened for read. */ |
| 414 | if (abfd->direction != read_direction |
| 415 | || sec->size == 0 |
| 416 | || sec->rawsize != 0 |
| 417 | || sec->contents != NULL |
| 418 | || sec->compress_status != COMPRESS_SECTION_NONE) |
| 419 | { |
| 420 | bfd_set_error (bfd_error_invalid_operation); |
| 421 | return FALSE; |
| 422 | } |
| 423 | |
| 424 | /* Read in the full section contents and compress it. */ |
| 425 | uncompressed_size = sec->size; |
| 426 | uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); |
| 427 | if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, |
| 428 | 0, uncompressed_size)) |
| 429 | ret = FALSE; |
| 430 | else |
| 431 | ret = bfd_compress_section_contents (abfd, sec, |
| 432 | uncompressed_buffer, |
| 433 | uncompressed_size); |
| 434 | |
| 435 | free (uncompressed_buffer); |
| 436 | return ret; |
| 437 | #endif |
| 438 | } |