1 /* Compressed section support (intended for debug sections). 2 Copyright 2008, 2010 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 = sec->rawsize ? sec->rawsize : sec->size; 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 (sz == 0) 173 return TRUE; 174 175 switch (sec->compress_status) 176 { 177 case COMPRESS_SECTION_NONE: 178 if (p == NULL) 179 { 180 p = (bfd_byte *) bfd_malloc (sz); 181 if (p == NULL) 182 return FALSE; 183 } 184 if (!bfd_get_section_contents (abfd, sec, p, 0, sz)) 185 { 186 if (*ptr != p) 187 free (p); 188 return FALSE; 189 } 190 *ptr = p; 191 return TRUE; 192 193 case DECOMPRESS_SECTION_SIZED: 194 #ifndef HAVE_ZLIB_H 195 bfd_set_error (bfd_error_invalid_operation); 196 return FALSE; 197 #else 198 /* Read in the full compressed section contents. */ 199 uncompressed_size = sec->size; 200 compressed_size = sec->compressed_size; 201 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size); 202 if (compressed_buffer == NULL) 203 return FALSE; 204 rawsize = sec->rawsize; 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 = compressed_size; 210 sec->compress_status = COMPRESS_SECTION_NONE; 211 ret = bfd_get_section_contents (abfd, sec, compressed_buffer, 212 0, compressed_size); 213 /* Restore rawsize and size. */ 214 sec->rawsize = rawsize; 215 sec->size = uncompressed_size; 216 sec->compress_status = DECOMPRESS_SECTION_SIZED; 217 if (!ret) 218 goto fail_compressed; 219 220 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 221 if (uncompressed_buffer == NULL) 222 goto fail_compressed; 223 224 if (!decompress_contents (compressed_buffer, compressed_size, 225 uncompressed_buffer, uncompressed_size)) 226 { 227 bfd_set_error (bfd_error_bad_value); 228 free (uncompressed_buffer); 229 fail_compressed: 230 free (compressed_buffer); 231 return FALSE; 232 } 233 234 free (compressed_buffer); 235 sec->contents = uncompressed_buffer; 236 sec->compress_status = COMPRESS_SECTION_DONE; 237 /* Fall thru */ 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_is_section_compressed 259 260 SYNOPSIS 261 bfd_boolean bfd_is_section_compressed 262 (bfd *abfd, asection *section); 263 264 DESCRIPTION 265 Return @code{TRUE} if @var{section} is compressed. 266 */ 267 268 bfd_boolean 269 bfd_is_section_compressed (bfd *abfd, sec_ptr sec) 270 { 271 bfd_byte compressed_buffer [12]; 272 273 /* Read the zlib header. In this case, it should be "ZLIB" followed 274 by the uncompressed section size, 8 bytes in big-endian order. */ 275 return (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12) 276 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")); 277 } 278 279 /* 280 FUNCTION 281 bfd_init_section_decompress_status 282 283 SYNOPSIS 284 bfd_boolean bfd_init_section_decompress_status 285 (bfd *abfd, asection *section); 286 287 DESCRIPTION 288 Record compressed section size, update section size with 289 decompressed size and set compress_status to 290 DECOMPRESS_SECTION_SIZED. 291 292 Return @code{FALSE} if the section is not a valid compressed 293 section or zlib is not installed on this machine. Otherwise, 294 return @code{TRUE}. 295 */ 296 297 bfd_boolean 298 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, 299 sec_ptr sec ATTRIBUTE_UNUSED) 300 { 301 #ifndef HAVE_ZLIB_H 302 bfd_set_error (bfd_error_invalid_operation); 303 return FALSE; 304 #else 305 bfd_byte compressed_buffer [12]; 306 bfd_size_type uncompressed_size; 307 308 if (sec->rawsize != 0 309 || sec->contents != NULL 310 || sec->compress_status != COMPRESS_SECTION_NONE 311 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) 312 { 313 bfd_set_error (bfd_error_invalid_operation); 314 return FALSE; 315 } 316 317 /* Read the zlib header. In this case, it should be "ZLIB" followed 318 by the uncompressed section size, 8 bytes in big-endian order. */ 319 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")) 320 { 321 bfd_set_error (bfd_error_wrong_format); 322 return FALSE; 323 } 324 325 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; 326 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; 327 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; 328 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; 329 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; 330 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; 331 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; 332 uncompressed_size += compressed_buffer[11]; 333 334 sec->compressed_size = sec->size; 335 sec->size = uncompressed_size; 336 sec->compress_status = DECOMPRESS_SECTION_SIZED; 337 338 return TRUE; 339 #endif 340 } 341 342 /* 343 FUNCTION 344 bfd_init_section_compress_status 345 346 SYNOPSIS 347 bfd_boolean bfd_init_section_compress_status 348 (bfd *abfd, asection *section); 349 350 DESCRIPTION 351 If open for read, compress section, update section size with 352 compressed size and set compress_status to COMPRESS_SECTION_DONE. 353 354 Return @code{FALSE} if the section is not a valid compressed 355 section or zlib is not installed on this machine. Otherwise, 356 return @code{TRUE}. 357 */ 358 359 bfd_boolean 360 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, 361 sec_ptr sec ATTRIBUTE_UNUSED) 362 { 363 #ifndef HAVE_ZLIB_H 364 bfd_set_error (bfd_error_invalid_operation); 365 return FALSE; 366 #else 367 bfd_size_type uncompressed_size; 368 bfd_byte *uncompressed_buffer; 369 bfd_boolean ret; 370 371 /* Error if not opened for read. */ 372 if (abfd->direction != read_direction 373 || sec->size == 0 374 || sec->rawsize != 0 375 || sec->contents != NULL 376 || sec->compress_status != COMPRESS_SECTION_NONE) 377 { 378 bfd_set_error (bfd_error_invalid_operation); 379 return FALSE; 380 } 381 382 /* Read in the full section contents and compress it. */ 383 uncompressed_size = sec->size; 384 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 385 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, 386 0, uncompressed_size)) 387 ret = FALSE; 388 else 389 ret = bfd_compress_section_contents (abfd, sec, 390 uncompressed_buffer, 391 uncompressed_size); 392 393 free (uncompressed_buffer); 394 return ret; 395 #endif 396 } 397