1 /* Compressed section support (intended for debug sections). 2 Copyright (C) 2008-2015 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. If the section has no contents then this function 156 returns @code{TRUE} but @var{*ptr} is set to NULL. 157 */ 158 159 bfd_boolean 160 bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr) 161 { 162 bfd_size_type sz; 163 bfd_byte *p = *ptr; 164 #ifdef HAVE_ZLIB_H 165 bfd_boolean ret; 166 bfd_size_type save_size; 167 bfd_size_type save_rawsize; 168 bfd_byte *compressed_buffer; 169 #endif 170 171 if (abfd->direction != write_direction && sec->rawsize != 0) 172 sz = sec->rawsize; 173 else 174 sz = sec->size; 175 if (sz == 0) 176 { 177 *ptr = NULL; 178 return TRUE; 179 } 180 181 switch (sec->compress_status) 182 { 183 case COMPRESS_SECTION_NONE: 184 if (p == NULL) 185 { 186 p = (bfd_byte *) bfd_malloc (sz); 187 if (p == NULL) 188 return FALSE; 189 } 190 191 if (!bfd_get_section_contents (abfd, sec, p, 0, sz)) 192 { 193 if (*ptr != p) 194 free (p); 195 return FALSE; 196 } 197 *ptr = p; 198 return TRUE; 199 200 case DECOMPRESS_SECTION_SIZED: 201 #ifndef HAVE_ZLIB_H 202 bfd_set_error (bfd_error_invalid_operation); 203 return FALSE; 204 #else 205 /* Read in the full compressed section contents. */ 206 compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size); 207 if (compressed_buffer == NULL) 208 return FALSE; 209 save_rawsize = sec->rawsize; 210 save_size = sec->size; 211 /* Clear rawsize, set size to compressed size and set compress_status 212 to COMPRESS_SECTION_NONE. If the compressed size is bigger than 213 the uncompressed size, bfd_get_section_contents will fail. */ 214 sec->rawsize = 0; 215 sec->size = sec->compressed_size; 216 sec->compress_status = COMPRESS_SECTION_NONE; 217 ret = bfd_get_section_contents (abfd, sec, compressed_buffer, 218 0, sec->compressed_size); 219 /* Restore rawsize and size. */ 220 sec->rawsize = save_rawsize; 221 sec->size = save_size; 222 sec->compress_status = DECOMPRESS_SECTION_SIZED; 223 if (!ret) 224 goto fail_compressed; 225 226 if (p == NULL) 227 p = (bfd_byte *) bfd_malloc (sz); 228 if (p == NULL) 229 goto fail_compressed; 230 231 if (!decompress_contents (compressed_buffer, sec->compressed_size, p, sz)) 232 { 233 bfd_set_error (bfd_error_bad_value); 234 if (p != *ptr) 235 free (p); 236 fail_compressed: 237 free (compressed_buffer); 238 return FALSE; 239 } 240 241 free (compressed_buffer); 242 *ptr = p; 243 return TRUE; 244 #endif 245 246 case COMPRESS_SECTION_DONE: 247 if (sec->contents == NULL) 248 return FALSE; 249 if (p == NULL) 250 { 251 p = (bfd_byte *) bfd_malloc (sz); 252 if (p == NULL) 253 return FALSE; 254 *ptr = p; 255 } 256 /* PR 17512; file: 5bc29788. */ 257 if (p != sec->contents) 258 memcpy (p, sec->contents, sz); 259 return TRUE; 260 261 default: 262 abort (); 263 } 264 } 265 266 /* 267 FUNCTION 268 bfd_cache_section_contents 269 270 SYNOPSIS 271 void bfd_cache_section_contents 272 (asection *sec, void *contents); 273 274 DESCRIPTION 275 Stash @var(contents) so any following reads of @var(sec) do 276 not need to decompress again. 277 */ 278 279 void 280 bfd_cache_section_contents (asection *sec, void *contents) 281 { 282 if (sec->compress_status == DECOMPRESS_SECTION_SIZED) 283 sec->compress_status = COMPRESS_SECTION_DONE; 284 sec->contents = contents; 285 sec->flags |= SEC_IN_MEMORY; 286 } 287 288 289 /* 290 FUNCTION 291 bfd_is_section_compressed 292 293 SYNOPSIS 294 bfd_boolean bfd_is_section_compressed 295 (bfd *abfd, asection *section); 296 297 DESCRIPTION 298 Return @code{TRUE} if @var{section} is compressed. 299 */ 300 301 bfd_boolean 302 bfd_is_section_compressed (bfd *abfd, sec_ptr sec) 303 { 304 bfd_byte compressed_buffer [12]; 305 unsigned int saved = sec->compress_status; 306 bfd_boolean compressed; 307 308 /* Don't decompress the section. */ 309 sec->compress_status = COMPRESS_SECTION_NONE; 310 311 /* Read the zlib header. In this case, it should be "ZLIB" followed 312 by the uncompressed section size, 8 bytes in big-endian order. */ 313 compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12) 314 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")); 315 316 /* Check for the pathalogical case of a debug string section that 317 contains the string ZLIB.... as the first entry. We assume that 318 no uncompressed .debug_str section would ever be big enough to 319 have the first byte of its (big-endian) size be non-zero. */ 320 if (compressed 321 && strcmp (sec->name, ".debug_str") == 0 322 && ISPRINT (compressed_buffer[4])) 323 compressed = FALSE; 324 325 /* Restore compress_status. */ 326 sec->compress_status = saved; 327 return compressed; 328 } 329 330 /* 331 FUNCTION 332 bfd_init_section_decompress_status 333 334 SYNOPSIS 335 bfd_boolean bfd_init_section_decompress_status 336 (bfd *abfd, asection *section); 337 338 DESCRIPTION 339 Record compressed section size, update section size with 340 decompressed size and set compress_status to 341 DECOMPRESS_SECTION_SIZED. 342 343 Return @code{FALSE} if the section is not a valid compressed 344 section or zlib is not installed on this machine. Otherwise, 345 return @code{TRUE}. 346 */ 347 348 bfd_boolean 349 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, 350 sec_ptr sec ATTRIBUTE_UNUSED) 351 { 352 #ifndef HAVE_ZLIB_H 353 bfd_set_error (bfd_error_invalid_operation); 354 return FALSE; 355 #else 356 bfd_byte compressed_buffer [12]; 357 bfd_size_type uncompressed_size; 358 359 if (sec->rawsize != 0 360 || sec->contents != NULL 361 || sec->compress_status != COMPRESS_SECTION_NONE 362 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) 363 { 364 bfd_set_error (bfd_error_invalid_operation); 365 return FALSE; 366 } 367 368 /* Read the zlib header. In this case, it should be "ZLIB" followed 369 by the uncompressed section size, 8 bytes in big-endian order. */ 370 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")) 371 { 372 bfd_set_error (bfd_error_wrong_format); 373 return FALSE; 374 } 375 376 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; 377 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; 378 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; 379 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; 380 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; 381 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; 382 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; 383 uncompressed_size += compressed_buffer[11]; 384 385 sec->compressed_size = sec->size; 386 sec->size = uncompressed_size; 387 sec->compress_status = DECOMPRESS_SECTION_SIZED; 388 389 return TRUE; 390 #endif 391 } 392 393 /* 394 FUNCTION 395 bfd_init_section_compress_status 396 397 SYNOPSIS 398 bfd_boolean bfd_init_section_compress_status 399 (bfd *abfd, asection *section); 400 401 DESCRIPTION 402 If open for read, compress section, update section size with 403 compressed size and set compress_status to COMPRESS_SECTION_DONE. 404 405 Return @code{FALSE} if the section is not a valid compressed 406 section or zlib is not installed on this machine. Otherwise, 407 return @code{TRUE}. 408 */ 409 410 bfd_boolean 411 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, 412 sec_ptr sec ATTRIBUTE_UNUSED) 413 { 414 #ifndef HAVE_ZLIB_H 415 bfd_set_error (bfd_error_invalid_operation); 416 return FALSE; 417 #else 418 bfd_size_type uncompressed_size; 419 bfd_byte *uncompressed_buffer; 420 bfd_boolean ret; 421 422 /* Error if not opened for read. */ 423 if (abfd->direction != read_direction 424 || sec->size == 0 425 || sec->rawsize != 0 426 || sec->contents != NULL 427 || sec->compress_status != COMPRESS_SECTION_NONE) 428 { 429 bfd_set_error (bfd_error_invalid_operation); 430 return FALSE; 431 } 432 433 /* Read in the full section contents and compress it. */ 434 uncompressed_size = sec->size; 435 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 436 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, 437 0, uncompressed_size)) 438 ret = FALSE; 439 else 440 ret = bfd_compress_section_contents (abfd, sec, 441 uncompressed_buffer, 442 uncompressed_size); 443 444 free (uncompressed_buffer); 445 return ret; 446 #endif 447 } 448