1 /* Compressed section support (intended for debug sections). 2 Copyright 2008, 2010, 2011 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 "config.h" 23 #include "sysdep.h" 24 #include "bfd.h" 25 #include "libbfd.h" 26 #ifdef HAVE_ZLIB_H 27 #include <zlib.h> 28 #endif 29 30 #ifdef HAVE_ZLIB_H 31 static bfd_boolean 32 decompress_contents (bfd_byte *compressed_buffer, 33 bfd_size_type compressed_size, 34 bfd_byte *uncompressed_buffer, 35 bfd_size_type uncompressed_size) 36 { 37 z_stream strm; 38 int rc; 39 40 /* It is possible the section consists of several compressed 41 buffers concatenated together, so we uncompress in a loop. */ 42 strm.zalloc = NULL; 43 strm.zfree = NULL; 44 strm.opaque = NULL; 45 strm.avail_in = compressed_size - 12; 46 strm.next_in = (Bytef*) compressed_buffer + 12; 47 strm.avail_out = uncompressed_size; 48 49 rc = inflateInit (&strm); 50 while (strm.avail_in > 0) 51 { 52 if (rc != Z_OK) 53 return FALSE; 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 return FALSE; 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 compressed_size; 166 bfd_size_type uncompressed_size; 167 bfd_size_type rawsize; 168 bfd_byte *compressed_buffer; 169 bfd_byte *uncompressed_buffer; 170 #endif 171 172 if (abfd->direction != write_direction && sec->rawsize != 0) 173 sz = sec->rawsize; 174 else 175 sz = sec->size; 176 if (sz == 0) 177 return TRUE; 178 179 switch (sec->compress_status) 180 { 181 case COMPRESS_SECTION_NONE: 182 if (p == NULL) 183 { 184 p = (bfd_byte *) bfd_malloc (sz); 185 if (p == NULL) 186 return FALSE; 187 } 188 if (!bfd_get_section_contents (abfd, sec, p, 0, sz)) 189 { 190 if (*ptr != p) 191 free (p); 192 return FALSE; 193 } 194 *ptr = p; 195 return TRUE; 196 197 case DECOMPRESS_SECTION_SIZED: 198 #ifndef HAVE_ZLIB_H 199 bfd_set_error (bfd_error_invalid_operation); 200 return FALSE; 201 #else 202 /* Read in the full compressed section contents. */ 203 uncompressed_size = sec->size; 204 compressed_size = sec->compressed_size; 205 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size); 206 if (compressed_buffer == NULL) 207 return FALSE; 208 rawsize = sec->rawsize; 209 /* Clear rawsize, set size to compressed size and set compress_status 210 to COMPRESS_SECTION_NONE. If the compressed size is bigger than 211 the uncompressed size, bfd_get_section_contents will fail. */ 212 sec->rawsize = 0; 213 sec->size = compressed_size; 214 sec->compress_status = COMPRESS_SECTION_NONE; 215 ret = bfd_get_section_contents (abfd, sec, compressed_buffer, 216 0, compressed_size); 217 /* Restore rawsize and size. */ 218 sec->rawsize = rawsize; 219 sec->size = uncompressed_size; 220 sec->compress_status = DECOMPRESS_SECTION_SIZED; 221 if (!ret) 222 goto fail_compressed; 223 224 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 225 if (uncompressed_buffer == NULL) 226 goto fail_compressed; 227 228 if (!decompress_contents (compressed_buffer, compressed_size, 229 uncompressed_buffer, uncompressed_size)) 230 { 231 bfd_set_error (bfd_error_bad_value); 232 free (uncompressed_buffer); 233 fail_compressed: 234 free (compressed_buffer); 235 return FALSE; 236 } 237 238 free (compressed_buffer); 239 sec->contents = uncompressed_buffer; 240 sec->compress_status = COMPRESS_SECTION_DONE; 241 /* Fall thru */ 242 #endif 243 244 case COMPRESS_SECTION_DONE: 245 if (p == NULL) 246 { 247 p = (bfd_byte *) bfd_malloc (sz); 248 if (p == NULL) 249 return FALSE; 250 *ptr = p; 251 } 252 memcpy (p, sec->contents, sz); 253 return TRUE; 254 255 default: 256 abort (); 257 } 258 } 259 260 /* 261 FUNCTION 262 bfd_is_section_compressed 263 264 SYNOPSIS 265 bfd_boolean bfd_is_section_compressed 266 (bfd *abfd, asection *section); 267 268 DESCRIPTION 269 Return @code{TRUE} if @var{section} is compressed. 270 */ 271 272 bfd_boolean 273 bfd_is_section_compressed (bfd *abfd, sec_ptr sec) 274 { 275 bfd_byte compressed_buffer [12]; 276 277 /* Read the zlib header. In this case, it should be "ZLIB" followed 278 by the uncompressed section size, 8 bytes in big-endian order. */ 279 return (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12) 280 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")); 281 } 282 283 /* 284 FUNCTION 285 bfd_init_section_decompress_status 286 287 SYNOPSIS 288 bfd_boolean bfd_init_section_decompress_status 289 (bfd *abfd, asection *section); 290 291 DESCRIPTION 292 Record compressed section size, update section size with 293 decompressed size and set compress_status to 294 DECOMPRESS_SECTION_SIZED. 295 296 Return @code{FALSE} if the section is not a valid compressed 297 section or zlib is not installed on this machine. Otherwise, 298 return @code{TRUE}. 299 */ 300 301 bfd_boolean 302 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, 303 sec_ptr sec ATTRIBUTE_UNUSED) 304 { 305 #ifndef HAVE_ZLIB_H 306 bfd_set_error (bfd_error_invalid_operation); 307 return FALSE; 308 #else 309 bfd_byte compressed_buffer [12]; 310 bfd_size_type uncompressed_size; 311 312 if (sec->rawsize != 0 313 || sec->contents != NULL 314 || sec->compress_status != COMPRESS_SECTION_NONE 315 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) 316 { 317 bfd_set_error (bfd_error_invalid_operation); 318 return FALSE; 319 } 320 321 /* Read the zlib header. In this case, it should be "ZLIB" followed 322 by the uncompressed section size, 8 bytes in big-endian order. */ 323 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")) 324 { 325 bfd_set_error (bfd_error_wrong_format); 326 return FALSE; 327 } 328 329 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; 330 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; 331 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; 332 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; 333 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; 334 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; 335 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; 336 uncompressed_size += compressed_buffer[11]; 337 338 sec->compressed_size = sec->size; 339 sec->size = uncompressed_size; 340 sec->compress_status = DECOMPRESS_SECTION_SIZED; 341 342 return TRUE; 343 #endif 344 } 345 346 /* 347 FUNCTION 348 bfd_init_section_compress_status 349 350 SYNOPSIS 351 bfd_boolean bfd_init_section_compress_status 352 (bfd *abfd, asection *section); 353 354 DESCRIPTION 355 If open for read, compress section, update section size with 356 compressed size and set compress_status to COMPRESS_SECTION_DONE. 357 358 Return @code{FALSE} if the section is not a valid compressed 359 section or zlib is not installed on this machine. Otherwise, 360 return @code{TRUE}. 361 */ 362 363 bfd_boolean 364 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, 365 sec_ptr sec ATTRIBUTE_UNUSED) 366 { 367 #ifndef HAVE_ZLIB_H 368 bfd_set_error (bfd_error_invalid_operation); 369 return FALSE; 370 #else 371 bfd_size_type uncompressed_size; 372 bfd_byte *uncompressed_buffer; 373 bfd_boolean ret; 374 375 /* Error if not opened for read. */ 376 if (abfd->direction != read_direction 377 || sec->size == 0 378 || sec->rawsize != 0 379 || sec->contents != NULL 380 || sec->compress_status != COMPRESS_SECTION_NONE) 381 { 382 bfd_set_error (bfd_error_invalid_operation); 383 return FALSE; 384 } 385 386 /* Read in the full section contents and compress it. */ 387 uncompressed_size = sec->size; 388 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 389 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, 390 0, uncompressed_size)) 391 ret = FALSE; 392 else 393 ret = bfd_compress_section_contents (abfd, sec, 394 uncompressed_buffer, 395 uncompressed_size); 396 397 free (uncompressed_buffer); 398 return ret; 399 #endif 400 } 401