1 /* Compressed section support (intended for debug sections). 2 Copyright 2008, 2010, 2011, 2012 3 Free Software Foundation, Inc. 4 5 This file is part of BFD, the Binary File Descriptor library. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 20 MA 02110-1301, USA. */ 21 22 #include "sysdep.h" 23 #include "bfd.h" 24 #include "libbfd.h" 25 #ifdef HAVE_ZLIB_H 26 #include <zlib.h> 27 #endif 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 /* Restore compress_status. */ 308 sec->compress_status = saved; 309 return compressed; 310 } 311 312 /* 313 FUNCTION 314 bfd_init_section_decompress_status 315 316 SYNOPSIS 317 bfd_boolean bfd_init_section_decompress_status 318 (bfd *abfd, asection *section); 319 320 DESCRIPTION 321 Record compressed section size, update section size with 322 decompressed size and set compress_status to 323 DECOMPRESS_SECTION_SIZED. 324 325 Return @code{FALSE} if the section is not a valid compressed 326 section or zlib is not installed on this machine. Otherwise, 327 return @code{TRUE}. 328 */ 329 330 bfd_boolean 331 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, 332 sec_ptr sec ATTRIBUTE_UNUSED) 333 { 334 #ifndef HAVE_ZLIB_H 335 bfd_set_error (bfd_error_invalid_operation); 336 return FALSE; 337 #else 338 bfd_byte compressed_buffer [12]; 339 bfd_size_type uncompressed_size; 340 341 if (sec->rawsize != 0 342 || sec->contents != NULL 343 || sec->compress_status != COMPRESS_SECTION_NONE 344 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) 345 { 346 bfd_set_error (bfd_error_invalid_operation); 347 return FALSE; 348 } 349 350 /* Read the zlib header. In this case, it should be "ZLIB" followed 351 by the uncompressed section size, 8 bytes in big-endian order. */ 352 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")) 353 { 354 bfd_set_error (bfd_error_wrong_format); 355 return FALSE; 356 } 357 358 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; 359 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; 360 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; 361 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; 362 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; 363 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; 364 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; 365 uncompressed_size += compressed_buffer[11]; 366 367 sec->compressed_size = sec->size; 368 sec->size = uncompressed_size; 369 sec->compress_status = DECOMPRESS_SECTION_SIZED; 370 371 return TRUE; 372 #endif 373 } 374 375 /* 376 FUNCTION 377 bfd_init_section_compress_status 378 379 SYNOPSIS 380 bfd_boolean bfd_init_section_compress_status 381 (bfd *abfd, asection *section); 382 383 DESCRIPTION 384 If open for read, compress section, update section size with 385 compressed size and set compress_status to COMPRESS_SECTION_DONE. 386 387 Return @code{FALSE} if the section is not a valid compressed 388 section or zlib is not installed on this machine. Otherwise, 389 return @code{TRUE}. 390 */ 391 392 bfd_boolean 393 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, 394 sec_ptr sec ATTRIBUTE_UNUSED) 395 { 396 #ifndef HAVE_ZLIB_H 397 bfd_set_error (bfd_error_invalid_operation); 398 return FALSE; 399 #else 400 bfd_size_type uncompressed_size; 401 bfd_byte *uncompressed_buffer; 402 bfd_boolean ret; 403 404 /* Error if not opened for read. */ 405 if (abfd->direction != read_direction 406 || sec->size == 0 407 || sec->rawsize != 0 408 || sec->contents != NULL 409 || sec->compress_status != COMPRESS_SECTION_NONE) 410 { 411 bfd_set_error (bfd_error_invalid_operation); 412 return FALSE; 413 } 414 415 /* Read in the full section contents and compress it. */ 416 uncompressed_size = sec->size; 417 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 418 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, 419 0, uncompressed_size)) 420 ret = FALSE; 421 else 422 ret = bfd_compress_section_contents (abfd, sec, 423 uncompressed_buffer, 424 uncompressed_size); 425 426 free (uncompressed_buffer); 427 return ret; 428 #endif 429 } 430