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 (compress ((Bytef*) compressed_buffer + 12, 104 &compressed_size, 105 (const Bytef*) uncompressed_buffer, 106 uncompressed_size) != Z_OK) 107 { 108 free (compressed_buffer); 109 bfd_set_error (bfd_error_bad_value); 110 return FALSE; 111 } 112 113 /* Write the zlib header. In this case, it should be "ZLIB" followed 114 by the uncompressed section size, 8 bytes in big-endian order. */ 115 memcpy (compressed_buffer, "ZLIB", 4); 116 compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8; 117 compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8; 118 compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8; 119 compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8; 120 compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8; 121 compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8; 122 compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8; 123 compressed_buffer[4] = uncompressed_size; 124 compressed_size += 12; 125 126 /* Free the uncompressed contents if we compress in place. */ 127 if (uncompressed_buffer == sec->contents) 128 free (uncompressed_buffer); 129 130 sec->contents = compressed_buffer; 131 sec->size = compressed_size; 132 sec->compress_status = COMPRESS_SECTION_DONE; 133 134 return TRUE; 135 #endif /* HAVE_ZLIB_H */ 136 } 137 138 /* 139 FUNCTION 140 bfd_get_full_section_contents 141 142 SYNOPSIS 143 bfd_boolean bfd_get_full_section_contents 144 (bfd *abfd, asection *section, bfd_byte **ptr); 145 146 DESCRIPTION 147 Read all data from @var{section} in BFD @var{abfd}, decompress 148 if needed, and store in @var{*ptr}. If @var{*ptr} is NULL, 149 return @var{*ptr} with memory malloc'd by this function. 150 151 Return @code{TRUE} if the full section contents is retrieved 152 successfully. 153 */ 154 155 bfd_boolean 156 bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr) 157 { 158 bfd_size_type sz = sec->rawsize ? sec->rawsize : sec->size; 159 bfd_byte *p = *ptr; 160 #ifdef HAVE_ZLIB_H 161 bfd_boolean ret; 162 bfd_size_type compressed_size; 163 bfd_size_type uncompressed_size; 164 bfd_size_type rawsize; 165 bfd_byte *compressed_buffer; 166 bfd_byte *uncompressed_buffer; 167 #endif 168 169 if (sz == 0) 170 return TRUE; 171 172 switch (sec->compress_status) 173 { 174 case COMPRESS_SECTION_NONE: 175 if (p == NULL) 176 { 177 p = (bfd_byte *) bfd_malloc (sz); 178 if (p == NULL) 179 return FALSE; 180 } 181 if (!bfd_get_section_contents (abfd, sec, p, 0, sz)) 182 { 183 if (*ptr != p) 184 free (p); 185 return FALSE; 186 } 187 *ptr = p; 188 return TRUE; 189 190 case DECOMPRESS_SECTION_SIZED: 191 #ifndef HAVE_ZLIB_H 192 bfd_set_error (bfd_error_invalid_operation); 193 return FALSE; 194 #else 195 /* Read in the full compressed section contents. */ 196 uncompressed_size = sec->size; 197 compressed_size = sec->compressed_size; 198 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size); 199 if (compressed_buffer == NULL) 200 return FALSE; 201 rawsize = sec->rawsize; 202 /* Clear rawsize, set size to compressed size and set compress_status 203 to COMPRESS_SECTION_NONE. If the compressed size is bigger than 204 the uncompressed size, bfd_get_section_contents will fail. */ 205 sec->rawsize = 0; 206 sec->size = compressed_size; 207 sec->compress_status = COMPRESS_SECTION_NONE; 208 ret = bfd_get_section_contents (abfd, sec, compressed_buffer, 209 0, compressed_size); 210 /* Restore rawsize and size. */ 211 sec->rawsize = rawsize; 212 sec->size = uncompressed_size; 213 sec->compress_status = DECOMPRESS_SECTION_SIZED; 214 if (!ret) 215 goto fail_compressed; 216 217 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 218 if (uncompressed_buffer == NULL) 219 goto fail_compressed; 220 221 if (!decompress_contents (compressed_buffer, compressed_size, 222 uncompressed_buffer, uncompressed_size)) 223 { 224 bfd_set_error (bfd_error_bad_value); 225 free (uncompressed_buffer); 226 fail_compressed: 227 free (compressed_buffer); 228 return FALSE; 229 } 230 231 free (compressed_buffer); 232 sec->contents = uncompressed_buffer; 233 sec->compress_status = COMPRESS_SECTION_DONE; 234 /* Fall thru */ 235 #endif 236 237 case COMPRESS_SECTION_DONE: 238 if (p == NULL) 239 { 240 p = (bfd_byte *) bfd_malloc (sz); 241 if (p == NULL) 242 return FALSE; 243 *ptr = p; 244 } 245 memcpy (p, sec->contents, sz); 246 return TRUE; 247 248 default: 249 abort (); 250 } 251 } 252 253 /* 254 FUNCTION 255 bfd_is_section_compressed 256 257 SYNOPSIS 258 bfd_boolean bfd_is_section_compressed 259 (bfd *abfd, asection *section); 260 261 DESCRIPTION 262 Return @code{TRUE} if @var{section} is compressed. 263 */ 264 265 bfd_boolean 266 bfd_is_section_compressed (bfd *abfd, sec_ptr sec) 267 { 268 bfd_byte compressed_buffer [12]; 269 270 /* Read the zlib header. In this case, it should be "ZLIB" followed 271 by the uncompressed section size, 8 bytes in big-endian order. */ 272 return (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12) 273 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")); 274 } 275 276 /* 277 FUNCTION 278 bfd_init_section_decompress_status 279 280 SYNOPSIS 281 bfd_boolean bfd_init_section_decompress_status 282 (bfd *abfd, asection *section); 283 284 DESCRIPTION 285 Record compressed section size, update section size with 286 decompressed size and set compress_status to 287 DECOMPRESS_SECTION_SIZED. 288 289 Return @code{FALSE} if the section is not a valid compressed 290 section or zlib is not installed on this machine. Otherwise, 291 return @code{TRUE}. 292 */ 293 294 bfd_boolean 295 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, 296 sec_ptr sec ATTRIBUTE_UNUSED) 297 { 298 #ifndef HAVE_ZLIB_H 299 bfd_set_error (bfd_error_invalid_operation); 300 return FALSE; 301 #else 302 bfd_byte compressed_buffer [12]; 303 bfd_size_type uncompressed_size; 304 305 if (sec->rawsize != 0 306 || sec->contents != NULL 307 || sec->compress_status != COMPRESS_SECTION_NONE 308 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) 309 { 310 bfd_set_error (bfd_error_invalid_operation); 311 return FALSE; 312 } 313 314 /* Read the zlib header. In this case, it should be "ZLIB" followed 315 by the uncompressed section size, 8 bytes in big-endian order. */ 316 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")) 317 { 318 bfd_set_error (bfd_error_wrong_format); 319 return FALSE; 320 } 321 322 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; 323 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; 324 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; 325 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; 326 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; 327 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; 328 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; 329 uncompressed_size += compressed_buffer[11]; 330 331 sec->compressed_size = sec->size; 332 sec->size = uncompressed_size; 333 sec->compress_status = DECOMPRESS_SECTION_SIZED; 334 335 return TRUE; 336 #endif 337 } 338 339 /* 340 FUNCTION 341 bfd_init_section_compress_status 342 343 SYNOPSIS 344 bfd_boolean bfd_init_section_compress_status 345 (bfd *abfd, asection *section); 346 347 DESCRIPTION 348 If open for read, compress section, update section size with 349 compressed size and set compress_status to COMPRESS_SECTION_DONE. 350 351 Return @code{FALSE} if the section is not a valid compressed 352 section or zlib is not installed on this machine. Otherwise, 353 return @code{TRUE}. 354 */ 355 356 bfd_boolean 357 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, 358 sec_ptr sec ATTRIBUTE_UNUSED) 359 { 360 #ifndef HAVE_ZLIB_H 361 bfd_set_error (bfd_error_invalid_operation); 362 return FALSE; 363 #else 364 bfd_size_type uncompressed_size; 365 bfd_byte *uncompressed_buffer; 366 bfd_boolean ret; 367 368 /* Error if not opened for read. */ 369 if (abfd->direction != read_direction 370 || sec->size == 0 371 || sec->rawsize != 0 372 || sec->contents != NULL 373 || sec->compress_status != COMPRESS_SECTION_NONE) 374 { 375 bfd_set_error (bfd_error_invalid_operation); 376 return FALSE; 377 } 378 379 /* Read in the full section contents and compress it. */ 380 uncompressed_size = sec->size; 381 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size); 382 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, 383 0, uncompressed_size)) 384 ret = FALSE; 385 else 386 ret = bfd_compress_section_contents (abfd, sec, 387 uncompressed_buffer, 388 uncompressed_size); 389 390 free (uncompressed_buffer); 391 return ret; 392 #endif 393 } 394