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) 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 compressed_size; 165 bfd_size_type uncompressed_size; 166 bfd_size_type rawsize; 167 bfd_byte *compressed_buffer; 168 bfd_byte *uncompressed_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 return TRUE; 177 178 switch (sec->compress_status) 179 { 180 case COMPRESS_SECTION_NONE: 181 if (p == NULL) 182 { 183 p = (bfd_byte *) bfd_malloc (sz); 184 if (p == NULL) 185 return FALSE; 186 } 187 if (!bfd_get_section_contents (abfd, sec, p, 0, sz)) 188 { 189 if (*ptr != p) 190 free (p); 191 return FALSE; 192 } 193 *ptr = p; 194 return TRUE; 195 196 case DECOMPRESS_SECTION_SIZED: 197 #ifndef HAVE_ZLIB_H 198 bfd_set_error (bfd_error_invalid_operation); 199 return FALSE; 200 #else 201 /* Read in the full compressed section contents. */ 202 uncompressed_size = sec->size; 203 compressed_size = sec->compressed_size; 204 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size); 205 if (compressed_buffer == NULL) 206 return FALSE; 207 rawsize = sec->rawsize; 208 /* Clear rawsize, set size to compressed size and set compress_status 209 to COMPRESS_SECTION_NONE. If the compressed size is bigger than 210 the uncompressed size, bfd_get_section_contents will fail. */ 211 sec->rawsize = 0; 212 sec->size = compressed_size; 213 sec->compress_status = COMPRESS_SECTION_NONE; 214 ret = bfd_get_section_contents (abfd, sec, compressed_buffer, 215 0, compressed_size); 216 /* Restore rawsize and size. */ 217 sec->rawsize = rawsize; 218 sec->size = uncompressed_size; 219 sec->compress_status = DECOMPRESS_SECTION_SIZED; 220 if (!ret) 221 goto fail_compressed; 222 223 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 224 if (uncompressed_buffer == NULL) 225 goto fail_compressed; 226 227 if (!decompress_contents (compressed_buffer, compressed_size, 228 uncompressed_buffer, uncompressed_size)) 229 { 230 bfd_set_error (bfd_error_bad_value); 231 free (uncompressed_buffer); 232 fail_compressed: 233 free (compressed_buffer); 234 return FALSE; 235 } 236 237 free (compressed_buffer); 238 sec->contents = uncompressed_buffer; 239 sec->compress_status = COMPRESS_SECTION_DONE; 240 /* Fall thru */ 241 #endif 242 243 case COMPRESS_SECTION_DONE: 244 if (p == NULL) 245 { 246 p = (bfd_byte *) bfd_malloc (sz); 247 if (p == NULL) 248 return FALSE; 249 *ptr = p; 250 } 251 memcpy (p, sec->contents, sz); 252 return TRUE; 253 254 default: 255 abort (); 256 } 257 } 258 259 /* 260 FUNCTION 261 bfd_is_section_compressed 262 263 SYNOPSIS 264 bfd_boolean bfd_is_section_compressed 265 (bfd *abfd, asection *section); 266 267 DESCRIPTION 268 Return @code{TRUE} if @var{section} is compressed. 269 */ 270 271 bfd_boolean 272 bfd_is_section_compressed (bfd *abfd, sec_ptr sec) 273 { 274 bfd_byte compressed_buffer [12]; 275 276 /* Read the zlib header. In this case, it should be "ZLIB" followed 277 by the uncompressed section size, 8 bytes in big-endian order. */ 278 return (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12) 279 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")); 280 } 281 282 /* 283 FUNCTION 284 bfd_init_section_decompress_status 285 286 SYNOPSIS 287 bfd_boolean bfd_init_section_decompress_status 288 (bfd *abfd, asection *section); 289 290 DESCRIPTION 291 Record compressed section size, update section size with 292 decompressed size and set compress_status to 293 DECOMPRESS_SECTION_SIZED. 294 295 Return @code{FALSE} if the section is not a valid compressed 296 section or zlib is not installed on this machine. Otherwise, 297 return @code{TRUE}. 298 */ 299 300 bfd_boolean 301 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, 302 sec_ptr sec ATTRIBUTE_UNUSED) 303 { 304 #ifndef HAVE_ZLIB_H 305 bfd_set_error (bfd_error_invalid_operation); 306 return FALSE; 307 #else 308 bfd_byte compressed_buffer [12]; 309 bfd_size_type uncompressed_size; 310 311 if (sec->rawsize != 0 312 || sec->contents != NULL 313 || sec->compress_status != COMPRESS_SECTION_NONE 314 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) 315 { 316 bfd_set_error (bfd_error_invalid_operation); 317 return FALSE; 318 } 319 320 /* Read the zlib header. In this case, it should be "ZLIB" followed 321 by the uncompressed section size, 8 bytes in big-endian order. */ 322 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")) 323 { 324 bfd_set_error (bfd_error_wrong_format); 325 return FALSE; 326 } 327 328 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; 329 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; 330 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; 331 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; 332 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; 333 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; 334 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; 335 uncompressed_size += compressed_buffer[11]; 336 337 sec->compressed_size = sec->size; 338 sec->size = uncompressed_size; 339 sec->compress_status = DECOMPRESS_SECTION_SIZED; 340 341 return TRUE; 342 #endif 343 } 344 345 /* 346 FUNCTION 347 bfd_init_section_compress_status 348 349 SYNOPSIS 350 bfd_boolean bfd_init_section_compress_status 351 (bfd *abfd, asection *section); 352 353 DESCRIPTION 354 If open for read, compress section, update section size with 355 compressed size and set compress_status to COMPRESS_SECTION_DONE. 356 357 Return @code{FALSE} if the section is not a valid compressed 358 section or zlib is not installed on this machine. Otherwise, 359 return @code{TRUE}. 360 */ 361 362 bfd_boolean 363 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, 364 sec_ptr sec ATTRIBUTE_UNUSED) 365 { 366 #ifndef HAVE_ZLIB_H 367 bfd_set_error (bfd_error_invalid_operation); 368 return FALSE; 369 #else 370 bfd_size_type uncompressed_size; 371 bfd_byte *uncompressed_buffer; 372 bfd_boolean ret; 373 374 /* Error if not opened for read. */ 375 if (abfd->direction != read_direction 376 || sec->size == 0 377 || sec->rawsize != 0 378 || sec->contents != NULL 379 || sec->compress_status != COMPRESS_SECTION_NONE) 380 { 381 bfd_set_error (bfd_error_invalid_operation); 382 return FALSE; 383 } 384 385 /* Read in the full section contents and compress it. */ 386 uncompressed_size = sec->size; 387 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 388 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, 389 0, uncompressed_size)) 390 ret = FALSE; 391 else 392 ret = bfd_compress_section_contents (abfd, sec, 393 uncompressed_buffer, 394 uncompressed_size); 395 396 free (uncompressed_buffer); 397 return ret; 398 #endif 399 } 400