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