bfd/bfdio.c

   1 /* Low-level I/O routines for BFDs.
   2
   3    Copyright (C) 1990-2024 Free Software Foundation, Inc.
   4
   5    Written by Cygnus Support.
   6
   7    This file is part of BFD, the Binary File Descriptor library.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  22    MA 02110-1301, USA.  */
  23
  24 #include "sysdep.h"
  25 #include <limits.h>
  26 #include "bfd.h"
  27 #include "libbfd.h"
  28 #include "aout/ar.h"
  29 #if defined (_WIN32)
  30 #include <windows.h>
  31 #include <locale.h>
  32 #endif
  33
  34 #ifndef S_IXUSR
  35 #define S_IXUSR 0100    /* Execute by owner.  */
  36 #endif
  37 #ifndef S_IXGRP
  38 #define S_IXGRP 0010    /* Execute by group.  */
  39 #endif
  40 #ifndef S_IXOTH
  41 #define S_IXOTH 0001    /* Execute by others.  */
  42 #endif
  43
  44 #ifndef FD_CLOEXEC
  45 #define FD_CLOEXEC 1
  46 #endif
  47
  48 file_ptr
  49 _bfd_real_ftell (FILE *file)
  50 {
  51 #if defined (HAVE_FTELLO64)
  52   return ftello64 (file);
  53 #elif defined (HAVE_FTELLO)
  54   return ftello (file);
  55 #else
  56   return ftell (file);
  57 #endif
  58 }
  59
  60 int
  61 _bfd_real_fseek (FILE *file, file_ptr offset, int whence)
  62 {
  63 #if defined (HAVE_FSEEKO64)
  64   return fseeko64 (file, offset, whence);
  65 #elif defined (HAVE_FSEEKO)
  66   return fseeko (file, offset, whence);
  67 #else
  68   return fseek (file, offset, whence);
  69 #endif
  70 }
  71
  72 /* Mark FILE as close-on-exec.  Return FILE.  FILE may be NULL, in
  73    which case nothing is done.  */
  74 static FILE *
  75 close_on_exec (FILE *file)
  76 {
  77 #if defined (HAVE_FILENO) && defined (F_GETFD)
  78   if (file)
  79     {
  80       int fd = fileno (file);
  81       int old = fcntl (fd, F_GETFD, 0);
  82       if (old >= 0)
  83         fcntl (fd, F_SETFD, old | FD_CLOEXEC);
  84     }
  85 #endif
  86   return file;
  87 }
  88
  89 FILE *
  90 _bfd_real_fopen (const char *filename, const char *modes)
  91 {
  92 #ifdef VMS
  93   char *vms_attr;
  94
  95   /* On VMS, fopen allows file attributes as optional arguments.
  96      We need to use them but we'd better to use the common prototype.
  97      In fopen-vms.h, they are separated from the mode with a comma.
  98      Split here.  */
  99   vms_attr = strchr (modes, ',');
 100   if (vms_attr != NULL)
 101     {
 102       /* Attributes found.  Split.  */
 103       size_t modes_len = strlen (modes) + 1;
 104       char attrs[modes_len + 1];
 105       char *at[3];
 106       int i;
 107
 108       memcpy (attrs, modes, modes_len);
 109       at[0] = attrs;
 110       for (i = 0; i < 2; i++)
 111         {
 112           at[i + 1] = strchr (at[i], ',');
 113           BFD_ASSERT (at[i + 1] != NULL);
 114           *(at[i + 1]++) = 0; /* Replace ',' with a nul, and skip it.  */
 115         }
 116       return close_on_exec (fopen (filename, at[0], at[1], at[2]));
 117     }
 118
 119 #elif defined (_WIN32)
 120   /* PR 25713: Handle extra long path names possibly containing '..' and '.'.  */
 121    wchar_t **     lpFilePart = {NULL};
 122    const wchar_t  prefix[] = L"\\\\?\\";
 123    const size_t   partPathLen = strlen (filename) + 1;
 124 #ifdef __MINGW32__
 125 #if !HAVE_DECL____LC_CODEPAGE_FUNC
 126 /* This prototype was added to locale.h in version 9.0 of MinGW-w64.  */
 127    _CRTIMP unsigned int __cdecl ___lc_codepage_func (void);
 128 #endif
 129    const unsigned int cp = ___lc_codepage_func ();
 130 #else
 131    const unsigned int cp = CP_UTF8;
 132 #endif
 133
 134    /* Converting the partial path from ascii to unicode.
 135       1) Get the length: Calling with lpWideCharStr set to null returns the length.
 136       2) Convert the string: Calling with cbMultiByte set to -1 includes the terminating null.  */
 137    size_t         partPathWSize = MultiByteToWideChar (cp, 0, filename, -1, NULL, 0);
 138    wchar_t *      partPath = calloc (partPathWSize, sizeof(wchar_t));
 139    size_t         ix;
 140
 141    MultiByteToWideChar (cp, 0, filename, -1, partPath, partPathWSize);
 142
 143    /* Convert any UNIX style path separators into the DOS i.e. backslash separator.  */
 144    for (ix = 0; ix < partPathLen; ix++)
 145      if (IS_UNIX_DIR_SEPARATOR(filename[ix]))
 146        partPath[ix] = '\\';
 147
 148    /* Getting the full path from the provided partial path.
 149       1) Get the length.
 150       2) Resolve the path.  */
 151    long       fullPathWSize = GetFullPathNameW (partPath, 0, NULL, lpFilePart);
 152    wchar_t *  fullPath = calloc (fullPathWSize + sizeof(prefix) + 1, sizeof(wchar_t));
 153
 154    wcscpy (fullPath, prefix);
 155
 156    int        prefixLen = sizeof(prefix) / sizeof(wchar_t);
 157
 158    /* Do not add a prefix to the null device.  */
 159    if (stricmp (filename, "nul") == 0)
 160     prefixLen = 1;
 161
 162    wchar_t *  fullPathOffset = fullPath + prefixLen - 1;
 163
 164    GetFullPathNameW (partPath, fullPathWSize, fullPathOffset, lpFilePart);
 165    free (partPath);
 166
 167    /* It is non-standard for modes to exceed 16 characters.  */
 168    wchar_t    modesW[16];
 169
 170    MultiByteToWideChar (cp, 0, modes, -1, modesW, sizeof(modesW));
 171
 172    FILE *     file = _wfopen (fullPath, modesW);
 173    free (fullPath);
 174
 175    return close_on_exec (file);
 176
 177 #elif defined (HAVE_FOPEN64)
 178   return close_on_exec (fopen64 (filename, modes));
 179
 180 #else
 181   return close_on_exec (fopen (filename, modes));
 182 #endif
 183 }
 184
 185 /*
 186 INTERNAL_DEFINITION
 187         struct bfd_iovec
 188
 189 DESCRIPTION
 190
 191         The <<struct bfd_iovec>> contains the internal file I/O class.
 192         Each <<BFD>> has an instance of this class and all file I/O is
 193         routed through it (it is assumed that the instance implements
 194         all methods listed below).
 195
 196 .struct bfd_iovec
 197 .{
 198 .  {* To avoid problems with macros, a "b" rather than "f"
 199 .     prefix is prepended to each method name.  *}
 200 .  {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
 201 .     bytes starting at PTR.  Return the number of bytes actually
 202 .     transfered (a read past end-of-file returns less than NBYTES),
 203 .     or -1 (setting <<bfd_error>>) if an error occurs.  *}
 204 .  file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
 205 .  file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
 206 .                      file_ptr nbytes);
 207 .  {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
 208 .     if an error occurs.  *}
 209 .  file_ptr (*btell) (struct bfd *abfd);
 210 .  {* For the following, on successful completion a value of 0 is returned.
 211 .     Otherwise, a value of -1 is returned (and <<bfd_error>> is set).  *}
 212 .  int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
 213 .  int (*bclose) (struct bfd *abfd);
 214 .  int (*bflush) (struct bfd *abfd);
 215 .  int (*bstat) (struct bfd *abfd, struct stat *sb);
 216 .  {* Mmap a part of the files. ADDR, LEN, PROT, FLAGS and OFFSET are the usual
 217 .     mmap parameter, except that LEN and OFFSET do not need to be page
 218 .     aligned.  Returns (void *)-1 on failure, mmapped address on success.
 219 .     Also write in MAP_ADDR the address of the page aligned buffer and in
 220 .     MAP_LEN the size mapped (a page multiple).  Use unmap with MAP_ADDR and
 221 .     MAP_LEN to unmap.  *}
 222 .  void *(*bmmap) (struct bfd *abfd, void *addr, bfd_size_type len,
 223 .                  int prot, int flags, file_ptr offset,
 224 .                  void **map_addr, bfd_size_type *map_len);
 225 .};
 226
 227 .extern const struct bfd_iovec _bfd_memory_iovec;
 228 .
 229 */
 230
 231
 232 /*
 233 FUNCTION
 234         bfd_read
 235
 236 SYNOPSIS
 237         bfd_size_type bfd_read (void *, bfd_size_type, bfd *)
 238                                 ATTRIBUTE_WARN_UNUSED_RESULT;
 239
 240 DESCRIPTION
 241         Attempt to read SIZE bytes from ABFD's iostream to PTR.
 242         Return the amount read.
 243 */
 244
 245 bfd_size_type
 246 bfd_read (void *ptr, bfd_size_type size, bfd *abfd)
 247 {
 248   file_ptr nread;
 249   bfd *element_bfd = abfd;
 250   ufile_ptr offset = 0;
 251
 252   while (abfd->my_archive != NULL
 253          && !bfd_is_thin_archive (abfd->my_archive))
 254     {
 255       offset += abfd->origin;
 256       abfd = abfd->my_archive;
 257     }
 258   offset += abfd->origin;
 259
 260   /* If this is a non-thin archive element, don't read past the end of
 261      this element.  */
 262   if (element_bfd->arelt_data != NULL
 263       && element_bfd->my_archive != NULL
 264       && !bfd_is_thin_archive (element_bfd->my_archive))
 265     {
 266       bfd_size_type maxbytes = arelt_size (element_bfd);
 267
 268       if (abfd->where < offset || abfd->where - offset >= maxbytes)
 269         {
 270           bfd_set_error (bfd_error_invalid_operation);
 271           return -1;
 272         }
 273       if (abfd->where - offset + size > maxbytes)
 274         size = maxbytes - (abfd->where - offset);
 275     }
 276
 277   if (abfd->iovec == NULL)
 278     {
 279       bfd_set_error (bfd_error_invalid_operation);
 280       return -1;
 281     }
 282
 283   if (abfd->last_io == bfd_io_write)
 284     {
 285       abfd->last_io = bfd_io_force;
 286       if (bfd_seek (abfd, 0, SEEK_CUR) != 0)
 287         return -1;
 288     }
 289   abfd->last_io = bfd_io_read;
 290
 291   nread = abfd->iovec->bread (abfd, ptr, size);
 292   if (nread != -1)
 293     abfd->where += nread;
 294
 295   return nread;
 296 }
 297
 298 /*
 299 FUNCTION
 300         bfd_write
 301
 302 SYNOPSIS
 303         bfd_size_type bfd_write (const void *, bfd_size_type, bfd *)
 304                                 ATTRIBUTE_WARN_UNUSED_RESULT;
 305
 306 DESCRIPTION
 307         Attempt to write SIZE bytes to ABFD's iostream from PTR.
 308         Return the amount written.
 309 */
 310
 311 bfd_size_type
 312 bfd_write (const void *ptr, bfd_size_type size, bfd *abfd)
 313 {
 314   file_ptr nwrote;
 315
 316   while (abfd->my_archive != NULL
 317          && !bfd_is_thin_archive (abfd->my_archive))
 318     abfd = abfd->my_archive;
 319
 320   if (abfd->iovec == NULL)
 321     {
 322       bfd_set_error (bfd_error_invalid_operation);
 323       return -1;
 324     }
 325
 326   if (abfd->last_io == bfd_io_read)
 327     {
 328       abfd->last_io = bfd_io_force;
 329       if (bfd_seek (abfd, 0, SEEK_CUR) != 0)
 330         return -1;
 331     }
 332   abfd->last_io = bfd_io_write;
 333
 334   nwrote = abfd->iovec->bwrite (abfd, ptr, size);
 335   if (nwrote != -1)
 336     abfd->where += nwrote;
 337   if ((bfd_size_type) nwrote != size)
 338     {
 339 #ifdef ENOSPC
 340       errno = ENOSPC;
 341 #endif
 342       bfd_set_error (bfd_error_system_call);
 343     }
 344   return nwrote;
 345 }
 346
 347 /*
 348 FUNCTION
 349         bfd_tell
 350
 351 SYNOPSIS
 352         file_ptr bfd_tell (bfd *) ATTRIBUTE_WARN_UNUSED_RESULT;
 353
 354 DESCRIPTION
 355         Return ABFD's iostream file position.
 356 */
 357
 358 file_ptr
 359 bfd_tell (bfd *abfd)
 360 {
 361   ufile_ptr offset = 0;
 362   file_ptr ptr;
 363
 364   while (abfd->my_archive != NULL
 365          && !bfd_is_thin_archive (abfd->my_archive))
 366     {
 367       offset += abfd->origin;
 368       abfd = abfd->my_archive;
 369     }
 370   offset += abfd->origin;
 371
 372   if (abfd->iovec == NULL)
 373     return 0;
 374
 375   ptr = abfd->iovec->btell (abfd);
 376   abfd->where = ptr;
 377   return ptr - offset;
 378 }
 379
 380 /*
 381 FUNCTION
 382         bfd_flush
 383
 384 SYNOPSIS
 385         int bfd_flush (bfd *);
 386
 387 DESCRIPTION
 388         Flush ABFD's iostream pending IO.
 389 */
 390
 391 int
 392 bfd_flush (bfd *abfd)
 393 {
 394   while (abfd->my_archive != NULL
 395          && !bfd_is_thin_archive (abfd->my_archive))
 396     abfd = abfd->my_archive;
 397
 398   if (abfd->iovec == NULL)
 399     return 0;
 400
 401   return abfd->iovec->bflush (abfd);
 402 }
 403
 404 /*
 405 FUNCTION
 406         bfd_stat
 407
 408 SYNOPSIS
 409         int bfd_stat (bfd *, struct stat *) ATTRIBUTE_WARN_UNUSED_RESULT;
 410
 411 DESCRIPTION
 412         Call fstat on ABFD's iostream.  Return 0 on success, and a
 413         negative value on failure.
 414 */
 415
 416 int
 417 bfd_stat (bfd *abfd, struct stat *statbuf)
 418 {
 419   int result;
 420
 421   while (abfd->my_archive != NULL
 422          && !bfd_is_thin_archive (abfd->my_archive))
 423     abfd = abfd->my_archive;
 424
 425   if (abfd->iovec == NULL)
 426     {
 427       bfd_set_error (bfd_error_invalid_operation);
 428       return -1;
 429     }
 430
 431   result = abfd->iovec->bstat (abfd, statbuf);
 432   if (result < 0)
 433     bfd_set_error (bfd_error_system_call);
 434   return result;
 435 }
 436
 437 /*
 438 FUNCTION
 439         bfd_seek
 440
 441 SYNOPSIS
 442         int bfd_seek (bfd *, file_ptr, int) ATTRIBUTE_WARN_UNUSED_RESULT;
 443
 444 DESCRIPTION
 445         Call fseek on ABFD's iostream.  Return 0 on success, and a
 446         negative value on failure.
 447 */
 448
 449 int
 450 bfd_seek (bfd *abfd, file_ptr position, int direction)
 451 {
 452   int result;
 453   ufile_ptr offset = 0;
 454
 455   while (abfd->my_archive != NULL
 456          && !bfd_is_thin_archive (abfd->my_archive))
 457     {
 458       offset += abfd->origin;
 459       abfd = abfd->my_archive;
 460     }
 461   offset += abfd->origin;
 462
 463   if (abfd->iovec == NULL)
 464     {
 465       bfd_set_error (bfd_error_invalid_operation);
 466       return -1;
 467     }
 468
 469   /* For the time being, a BFD may not seek to it's end.  The problem
 470      is that we don't easily have a way to recognize the end of an
 471      element in an archive.  */
 472   BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);
 473
 474   if (direction != SEEK_CUR)
 475     position += offset;
 476
 477   if (((direction == SEEK_CUR && position == 0)
 478        || (direction == SEEK_SET && (ufile_ptr) position == abfd->where))
 479       && abfd->last_io != bfd_io_force)
 480     return 0;
 481
 482   abfd->last_io = bfd_io_seek;
 483
 484   result = abfd->iovec->bseek (abfd, position, direction);
 485   if (result != 0)
 486     {
 487       /* An EINVAL error probably means that the file offset was
 488          absurd.  */
 489       if (errno == EINVAL)
 490         bfd_set_error (bfd_error_file_truncated);
 491       else
 492         bfd_set_error (bfd_error_system_call);
 493     }
 494   else
 495     {
 496       /* Adjust `where' field.  */
 497       if (direction == SEEK_CUR)
 498         abfd->where += position;
 499       else
 500         abfd->where = position;
 501     }
 502
 503   return result;
 504 }
 505
 506 /*
 507 FUNCTION
 508         bfd_get_mtime
 509
 510 SYNOPSIS
 511         long bfd_get_mtime (bfd *abfd);
 512
 513 DESCRIPTION
 514         Return the file modification time (as read from the file system, or
 515         from the archive header for archive members).
 516
 517 */
 518
 519 long
 520 bfd_get_mtime (bfd *abfd)
 521 {
 522   struct stat buf;
 523
 524   if (abfd->mtime_set)
 525     return abfd->mtime;
 526
 527   if (bfd_stat (abfd, &buf) != 0)
 528     return 0;
 529
 530   abfd->mtime = buf.st_mtime;           /* Save value in case anyone wants it */
 531   return buf.st_mtime;
 532 }
 533
 534 /*
 535 FUNCTION
 536         bfd_get_size
 537
 538 SYNOPSIS
 539         ufile_ptr bfd_get_size (bfd *abfd);
 540
 541 DESCRIPTION
 542         Return the file size (as read from file system) for the file
 543         associated with BFD @var{abfd}.
 544
 545         The initial motivation for, and use of, this routine is not
 546         so we can get the exact size of the object the BFD applies to, since
 547         that might not be generally possible (archive members for example).
 548         It would be ideal if someone could eventually modify
 549         it so that such results were guaranteed.
 550
 551         Instead, we want to ask questions like "is this NNN byte sized
 552         object I'm about to try read from file offset YYY reasonable?"
 553         As as example of where we might do this, some object formats
 554         use string tables for which the first <<sizeof (long)>> bytes of the
 555         table contain the size of the table itself, including the size bytes.
 556         If an application tries to read what it thinks is one of these
 557         string tables, without some way to validate the size, and for
 558         some reason the size is wrong (byte swapping error, wrong location
 559         for the string table, etc.), the only clue is likely to be a read
 560         error when it tries to read the table, or a "virtual memory
 561         exhausted" error when it tries to allocate 15 bazillon bytes
 562         of space for the 15 bazillon byte table it is about to read.
 563         This function at least allows us to answer the question, "is the
 564         size reasonable?".
 565
 566         A return value of zero indicates the file size is unknown.
 567 */
 568
 569 ufile_ptr
 570 bfd_get_size (bfd *abfd)
 571 {
 572   /* A size of 0 means we haven't yet called bfd_stat.  A size of 1
 573      means we have a cached value of 0, ie. unknown.  */
 574   if (abfd->size <= 1 || bfd_write_p (abfd))
 575     {
 576       struct stat buf;
 577
 578       if (abfd->size == 1 && !bfd_write_p (abfd))
 579         return 0;
 580
 581       if (bfd_stat (abfd, &buf) != 0
 582           || buf.st_size == 0
 583           || buf.st_size - (ufile_ptr) buf.st_size != 0)
 584         {
 585           abfd->size = 1;
 586           return 0;
 587         }
 588       abfd->size = buf.st_size;
 589     }
 590   return abfd->size;
 591 }
 592
 593 /*
 594 FUNCTION
 595         bfd_get_file_size
 596
 597 SYNOPSIS
 598         ufile_ptr bfd_get_file_size (bfd *abfd);
 599
 600 DESCRIPTION
 601         Return the file size (as read from file system) for the file
 602         associated with BFD @var{abfd}.  It supports both normal files
 603         and archive elements.
 604
 605 */
 606
 607 ufile_ptr
 608 bfd_get_file_size (bfd *abfd)
 609 {
 610   ufile_ptr file_size, archive_size = (ufile_ptr) -1;
 611   unsigned int compression_p2 = 0;
 612
 613   if (abfd->my_archive != NULL
 614       && !bfd_is_thin_archive (abfd->my_archive))
 615     {
 616       struct areltdata *adata = (struct areltdata *) abfd->arelt_data;
 617       if (adata != NULL)
 618         {
 619           archive_size = adata->parsed_size;
 620           /* If the archive is compressed, assume an element won't
 621              expand more than eight times file size.  */
 622           if (adata->arch_header != NULL
 623               && memcmp (((struct ar_hdr *) adata->arch_header)->ar_fmag,
 624                          "Z\012", 2) == 0)
 625             compression_p2 = 3;
 626           abfd = abfd->my_archive;
 627         }
 628     }
 629
 630   file_size = bfd_get_size (abfd) << compression_p2;
 631   if (archive_size < file_size)
 632     return archive_size;
 633   return file_size;
 634 }
 635
 636 /*
 637 FUNCTION
 638         bfd_mmap
 639
 640 SYNOPSIS
 641         void *bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
 642                         int prot, int flags, file_ptr offset,
 643                         void **map_addr, bfd_size_type *map_len)
 644                         ATTRIBUTE_WARN_UNUSED_RESULT;
 645
 646 DESCRIPTION
 647         Return mmap()ed region of the file, if possible and implemented.
 648         LEN and OFFSET do not need to be page aligned.  The page aligned
 649         address and length are written to MAP_ADDR and MAP_LEN.
 650
 651 */
 652
 653 void *
 654 bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
 655           int prot, int flags, file_ptr offset,
 656           void **map_addr, bfd_size_type *map_len)
 657 {
 658   while (abfd->my_archive != NULL
 659          && !bfd_is_thin_archive (abfd->my_archive))
 660     {
 661       offset += abfd->origin;
 662       abfd = abfd->my_archive;
 663     }
 664   offset += abfd->origin;
 665
 666   if (abfd->iovec == NULL)
 667     {
 668       bfd_set_error (bfd_error_invalid_operation);
 669       return (void *) -1;
 670     }
 671
 672   return abfd->iovec->bmmap (abfd, addr, len, prot, flags, offset,
 673                              map_addr, map_len);
 674 }
 675
 676 /* Memory file I/O operations.  */
 677
 678 static file_ptr
 679 memory_bread (bfd *abfd, void *ptr, file_ptr size)
 680 {
 681   struct bfd_in_memory *bim;
 682   bfd_size_type get;
 683
 684   bim = (struct bfd_in_memory *) abfd->iostream;
 685   get = size;
 686   if (abfd->where + get > bim->size)
 687     {
 688       if (bim->size < (bfd_size_type) abfd->where)
 689         get = 0;
 690       else
 691         get = bim->size - abfd->where;
 692       bfd_set_error (bfd_error_file_truncated);
 693     }
 694   memcpy (ptr, bim->buffer + abfd->where, (size_t) get);
 695   return get;
 696 }
 697
 698 static file_ptr
 699 memory_bwrite (bfd *abfd, const void *ptr, file_ptr size)
 700 {
 701   struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
 702
 703   if (abfd->where + size > bim->size)
 704     {
 705       bfd_size_type newsize, oldsize;
 706
 707       oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
 708       bim->size = abfd->where + size;
 709       /* Round up to cut down on memory fragmentation */
 710       newsize = (bim->size + 127) & ~(bfd_size_type) 127;
 711       if (newsize > oldsize)
 712         {
 713           bim->buffer = (bfd_byte *) bfd_realloc_or_free (bim->buffer, newsize);
 714           if (bim->buffer == NULL)
 715             {
 716               bim->size = 0;
 717               return 0;
 718             }
 719           if (newsize > bim->size)
 720             memset (bim->buffer + bim->size, 0, newsize - bim->size);
 721         }
 722     }
 723   memcpy (bim->buffer + abfd->where, ptr, (size_t) size);
 724   return size;
 725 }
 726
 727 static file_ptr
 728 memory_btell (bfd *abfd)
 729 {
 730   return abfd->where;
 731 }
 732
 733 static int
 734 memory_bseek (bfd *abfd, file_ptr position, int direction)
 735 {
 736   file_ptr nwhere;
 737   struct bfd_in_memory *bim;
 738
 739   bim = (struct bfd_in_memory *) abfd->iostream;
 740
 741   if (direction == SEEK_SET)
 742     nwhere = position;
 743   else
 744     nwhere = abfd->where + position;
 745
 746   if (nwhere < 0)
 747     {
 748       abfd->where = 0;
 749       errno = EINVAL;
 750       return -1;
 751     }
 752
 753   if ((bfd_size_type)nwhere > bim->size)
 754     {
 755       if (abfd->direction == write_direction
 756           || abfd->direction == both_direction)
 757         {
 758           bfd_size_type newsize, oldsize;
 759
 760           oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
 761           bim->size = nwhere;
 762           /* Round up to cut down on memory fragmentation */
 763           newsize = (bim->size + 127) & ~(bfd_size_type) 127;
 764           if (newsize > oldsize)
 765             {
 766               bim->buffer = (bfd_byte *) bfd_realloc_or_free (bim->buffer, newsize);
 767               if (bim->buffer == NULL)
 768                 {
 769                   errno = EINVAL;
 770                   bim->size = 0;
 771                   return -1;
 772                 }
 773               memset (bim->buffer + oldsize, 0, newsize - oldsize);
 774             }
 775         }
 776       else
 777         {
 778           abfd->where = bim->size;
 779           errno = EINVAL;
 780           bfd_set_error (bfd_error_file_truncated);
 781           return -1;
 782         }
 783     }
 784   return 0;
 785 }
 786
 787 static int
 788 memory_bclose (struct bfd *abfd)
 789 {
 790   struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
 791
 792   free (bim->buffer);
 793   free (bim);
 794   abfd->iostream = NULL;
 795
 796   return 0;
 797 }
 798
 799 static int
 800 memory_bflush (bfd *abfd ATTRIBUTE_UNUSED)
 801 {
 802   return 0;
 803 }
 804
 805 static int
 806 memory_bstat (bfd *abfd, struct stat *statbuf)
 807 {
 808   struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
 809
 810   memset (statbuf, 0, sizeof (*statbuf));
 811   statbuf->st_size = bim->size;
 812
 813   return 0;
 814 }
 815
 816 static void *
 817 memory_bmmap (bfd *abfd ATTRIBUTE_UNUSED, void *addr ATTRIBUTE_UNUSED,
 818               bfd_size_type len ATTRIBUTE_UNUSED, int prot ATTRIBUTE_UNUSED,
 819               int flags ATTRIBUTE_UNUSED, file_ptr offset ATTRIBUTE_UNUSED,
 820               void **map_addr ATTRIBUTE_UNUSED,
 821               bfd_size_type *map_len ATTRIBUTE_UNUSED)
 822 {
 823   return (void *)-1;
 824 }
 825
 826 const struct bfd_iovec _bfd_memory_iovec =
 827 {
 828   &memory_bread, &memory_bwrite, &memory_btell, &memory_bseek,
 829   &memory_bclose, &memory_bflush, &memory_bstat, &memory_bmmap
 830 };
 831
 832 /*
 833 FUNCTION
 834         bfd_get_current_time
 835
 836 SYNOPSIS
 837         time_t bfd_get_current_time (time_t now);
 838
 839 DESCRIPTION
 840         Returns the current time.
 841
 842         If the environment variable SOURCE_DATE_EPOCH is defined
 843         then this is parsed and its value is returned.  Otherwise
 844         if the paramter NOW is non-zero, then that is returned.
 845         Otherwise the result of the system call "time(NULL)" is
 846         returned.
 847 */
 848
 849 time_t
 850 bfd_get_current_time (time_t now)
 851 {
 852   char *source_date_epoch;
 853   unsigned long long epoch;
 854
 855   /* FIXME: We could probably cache this lookup,
 856      and the parsing of its value below.  */
 857   source_date_epoch = getenv ("SOURCE_DATE_EPOCH");
 858
 859   if (source_date_epoch == NULL)
 860     {
 861       if (now)
 862         return now;
 863       return time (NULL);
 864     }
 865
 866   epoch = strtoull (source_date_epoch, NULL, 0);
 867
 868   /* If epoch == 0 then something is wrong with SOURCE_DATE_EPOCH,
 869      but we do not have an easy way to report it.  Since the presence
 870      of the environment variable implies that the user wants
 871      deterministic behaviour we just accept the 0 value.  */
 872
 873   return (time_t) epoch;
 874 }