1 /* Low-level I/O routines for BFDs.
3 Copyright (C) 1990-2018 Free Software Foundation, Inc.
5 Written by Cygnus Support.
7 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
30 #define S_IXUSR 0100 /* Execute by owner. */
33 #define S_IXGRP 0010 /* Execute by group. */
36 #define S_IXOTH 0001 /* Execute by others. */
44 _bfd_real_ftell (FILE *file)
46 #if defined (HAVE_FTELLO64)
47 return ftello64 (file);
48 #elif defined (HAVE_FTELLO)
56 _bfd_real_fseek (FILE *file, file_ptr offset, int whence)
58 #if defined (HAVE_FSEEKO64)
59 return fseeko64 (file, offset, whence);
60 #elif defined (HAVE_FSEEKO)
61 return fseeko (file, offset, whence);
63 return fseek (file, offset, whence);
67 /* Mark FILE as close-on-exec. Return FILE. FILE may be NULL, in
68 which case nothing is done. */
70 close_on_exec (FILE *file)
72 #if defined (HAVE_FILENO) && defined (F_GETFD)
75 int fd = fileno (file);
76 int old = fcntl (fd, F_GETFD, 0);
78 fcntl (fd, F_SETFD, old | FD_CLOEXEC);
85 _bfd_real_fopen (const char *filename, const char *modes)
90 /* On VMS, fopen allows file attributes as optional arguments.
91 We need to use them but we'd better to use the common prototype.
92 In fopen-vms.h, they are separated from the mode with a comma.
94 vms_attr = strchr (modes, ',');
98 return close_on_exec (fopen (filename, modes));
102 /* Attributes found. Split. */
103 size_t modes_len = strlen (modes) + 1;
104 char attrs[modes_len + 1];
108 memcpy (attrs, modes, modes_len);
110 for (i = 0; i < 2; i++)
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. */
116 return close_on_exec (fopen (filename, at[0], at[1], at[2]));
119 #if defined (HAVE_FOPEN64)
120 return close_on_exec (fopen64 (filename, modes));
122 return close_on_exec (fopen (filename, modes));
133 The <<struct bfd_iovec>> contains the internal file I/O class.
134 Each <<BFD>> has an instance of this class and all file I/O is
135 routed through it (it is assumed that the instance implements
136 all methods listed below).
140 . {* To avoid problems with macros, a "b" rather than "f"
141 . prefix is prepended to each method name. *}
142 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
143 . bytes starting at PTR. Return the number of bytes actually
144 . transfered (a read past end-of-file returns less than NBYTES),
145 . or -1 (setting <<bfd_error>>) if an error occurs. *}
146 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
147 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
149 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
150 . if an error occurs. *}
151 . file_ptr (*btell) (struct bfd *abfd);
152 . {* For the following, on successful completion a value of 0 is returned.
153 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
154 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
155 . int (*bclose) (struct bfd *abfd);
156 . int (*bflush) (struct bfd *abfd);
157 . int (*bstat) (struct bfd *abfd, struct stat *sb);
158 . {* Mmap a part of the files. ADDR, LEN, PROT, FLAGS and OFFSET are the usual
159 . mmap parameter, except that LEN and OFFSET do not need to be page
160 . aligned. Returns (void *)-1 on failure, mmapped address on success.
161 . Also write in MAP_ADDR the address of the page aligned buffer and in
162 . MAP_LEN the size mapped (a page multiple). Use unmap with MAP_ADDR and
163 . MAP_LEN to unmap. *}
164 . void *(*bmmap) (struct bfd *abfd, void *addr, bfd_size_type len,
165 . int prot, int flags, file_ptr offset,
166 . void **map_addr, bfd_size_type *map_len);
169 .extern const struct bfd_iovec _bfd_memory_iovec;
174 /* Return value is amount read. */
177 bfd_bread (void *ptr, bfd_size_type size, bfd *abfd)
180 bfd *element_bfd = abfd;
181 ufile_ptr offset = 0;
183 while (abfd->my_archive != NULL
184 && !bfd_is_thin_archive (abfd->my_archive))
186 offset += abfd->origin;
187 abfd = abfd->my_archive;
190 /* If this is an archive element, don't read past the end of
192 if (element_bfd->arelt_data != NULL)
194 bfd_size_type maxbytes = arelt_size (element_bfd);
196 if (abfd->where < offset || abfd->where - offset >= maxbytes)
198 bfd_set_error (bfd_error_invalid_operation);
201 if (abfd->where - offset + size > maxbytes)
202 size = maxbytes - (abfd->where - offset);
205 if (abfd->iovec == NULL)
207 bfd_set_error (bfd_error_invalid_operation);
211 nread = abfd->iovec->bread (abfd, ptr, size);
213 abfd->where += nread;
219 bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd)
223 while (abfd->my_archive != NULL
224 && !bfd_is_thin_archive (abfd->my_archive))
225 abfd = abfd->my_archive;
227 if (abfd->iovec == NULL)
229 bfd_set_error (bfd_error_invalid_operation);
233 nwrote = abfd->iovec->bwrite (abfd, ptr, size);
235 abfd->where += nwrote;
236 if ((bfd_size_type) nwrote != size)
241 bfd_set_error (bfd_error_system_call);
249 ufile_ptr offset = 0;
252 while (abfd->my_archive != NULL
253 && !bfd_is_thin_archive (abfd->my_archive))
255 offset += abfd->origin;
256 abfd = abfd->my_archive;
259 if (abfd->iovec == NULL)
262 ptr = abfd->iovec->btell (abfd);
268 bfd_flush (bfd *abfd)
270 while (abfd->my_archive != NULL
271 && !bfd_is_thin_archive (abfd->my_archive))
272 abfd = abfd->my_archive;
274 if (abfd->iovec == NULL)
277 return abfd->iovec->bflush (abfd);
280 /* Returns 0 for success, negative value for failure (in which case
281 bfd_get_error can retrieve the error code). */
283 bfd_stat (bfd *abfd, struct stat *statbuf)
287 while (abfd->my_archive != NULL
288 && !bfd_is_thin_archive (abfd->my_archive))
289 abfd = abfd->my_archive;
291 if (abfd->iovec == NULL)
293 bfd_set_error (bfd_error_invalid_operation);
297 result = abfd->iovec->bstat (abfd, statbuf);
299 bfd_set_error (bfd_error_system_call);
303 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
304 can retrieve the error code). */
307 bfd_seek (bfd *abfd, file_ptr position, int direction)
310 ufile_ptr offset = 0;
312 while (abfd->my_archive != NULL
313 && !bfd_is_thin_archive (abfd->my_archive))
315 offset += abfd->origin;
316 abfd = abfd->my_archive;
319 if (abfd->iovec == NULL)
321 bfd_set_error (bfd_error_invalid_operation);
325 /* For the time being, a BFD may not seek to it's end. The problem
326 is that we don't easily have a way to recognize the end of an
327 element in an archive. */
328 BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);
330 if (direction != SEEK_CUR)
333 result = abfd->iovec->bseek (abfd, position, direction);
336 /* An EINVAL error probably means that the file offset was
339 bfd_set_error (bfd_error_file_truncated);
341 bfd_set_error (bfd_error_system_call);
345 /* Adjust `where' field. */
346 if (direction == SEEK_CUR)
347 abfd->where += position;
349 abfd->where = position;
360 long bfd_get_mtime (bfd *abfd);
363 Return the file modification time (as read from the file system, or
364 from the archive header for archive members).
369 bfd_get_mtime (bfd *abfd)
376 if (bfd_stat (abfd, &buf) != 0)
379 abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */
388 ufile_ptr bfd_get_size (bfd *abfd);
391 Return the file size (as read from file system) for the file
392 associated with BFD @var{abfd}.
394 The initial motivation for, and use of, this routine is not
395 so we can get the exact size of the object the BFD applies to, since
396 that might not be generally possible (archive members for example).
397 It would be ideal if someone could eventually modify
398 it so that such results were guaranteed.
400 Instead, we want to ask questions like "is this NNN byte sized
401 object I'm about to try read from file offset YYY reasonable?"
402 As as example of where we might do this, some object formats
403 use string tables for which the first <<sizeof (long)>> bytes of the
404 table contain the size of the table itself, including the size bytes.
405 If an application tries to read what it thinks is one of these
406 string tables, without some way to validate the size, and for
407 some reason the size is wrong (byte swapping error, wrong location
408 for the string table, etc.), the only clue is likely to be a read
409 error when it tries to read the table, or a "virtual memory
410 exhausted" error when it tries to allocate 15 bazillon bytes
411 of space for the 15 bazillon byte table it is about to read.
412 This function at least allows us to answer the question, "is the
417 bfd_get_size (bfd *abfd)
421 if (bfd_stat (abfd, &buf) != 0)
432 ufile_ptr bfd_get_file_size (bfd *abfd);
435 Return the file size (as read from file system) for the file
436 associated with BFD @var{abfd}. It supports both normal files
437 and archive elements.
442 bfd_get_file_size (bfd *abfd)
444 if (abfd->my_archive != NULL
445 && !bfd_is_thin_archive (abfd->my_archive))
446 return arelt_size (abfd);
448 return bfd_get_size (abfd);
456 void *bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
457 int prot, int flags, file_ptr offset,
458 void **map_addr, bfd_size_type *map_len);
461 Return mmap()ed region of the file, if possible and implemented.
462 LEN and OFFSET do not need to be page aligned. The page aligned
463 address and length are written to MAP_ADDR and MAP_LEN.
468 bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
469 int prot, int flags, file_ptr offset,
470 void **map_addr, bfd_size_type *map_len)
472 while (abfd->my_archive != NULL
473 && !bfd_is_thin_archive (abfd->my_archive))
475 offset += abfd->origin;
476 abfd = abfd->my_archive;
479 if (abfd->iovec == NULL)
481 bfd_set_error (bfd_error_invalid_operation);
485 return abfd->iovec->bmmap (abfd, addr, len, prot, flags, offset,
489 /* Memory file I/O operations. */
492 memory_bread (bfd *abfd, void *ptr, file_ptr size)
494 struct bfd_in_memory *bim;
497 bim = (struct bfd_in_memory *) abfd->iostream;
499 if (abfd->where + get > bim->size)
501 if (bim->size < (bfd_size_type) abfd->where)
504 get = bim->size - abfd->where;
505 bfd_set_error (bfd_error_file_truncated);
507 memcpy (ptr, bim->buffer + abfd->where, (size_t) get);
512 memory_bwrite (bfd *abfd, const void *ptr, file_ptr size)
514 struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
516 if (abfd->where + size > bim->size)
518 bfd_size_type newsize, oldsize;
520 oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
521 bim->size = abfd->where + size;
522 /* Round up to cut down on memory fragmentation */
523 newsize = (bim->size + 127) & ~(bfd_size_type) 127;
524 if (newsize > oldsize)
526 bim->buffer = (bfd_byte *) bfd_realloc_or_free (bim->buffer, newsize);
527 if (bim->buffer == NULL)
532 if (newsize > bim->size)
533 memset (bim->buffer + bim->size, 0, newsize - bim->size);
536 memcpy (bim->buffer + abfd->where, ptr, (size_t) size);
541 memory_btell (bfd *abfd)
547 memory_bseek (bfd *abfd, file_ptr position, int direction)
550 struct bfd_in_memory *bim;
552 bim = (struct bfd_in_memory *) abfd->iostream;
554 if (direction == SEEK_SET)
557 nwhere = abfd->where + position;
566 if ((bfd_size_type)nwhere > bim->size)
568 if (abfd->direction == write_direction
569 || abfd->direction == both_direction)
571 bfd_size_type newsize, oldsize;
573 oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
575 /* Round up to cut down on memory fragmentation */
576 newsize = (bim->size + 127) & ~(bfd_size_type) 127;
577 if (newsize > oldsize)
579 bim->buffer = (bfd_byte *) bfd_realloc_or_free (bim->buffer, newsize);
580 if (bim->buffer == NULL)
586 memset (bim->buffer + oldsize, 0, newsize - oldsize);
591 abfd->where = bim->size;
593 bfd_set_error (bfd_error_file_truncated);
601 memory_bclose (struct bfd *abfd)
603 struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
605 if (bim->buffer != NULL)
608 abfd->iostream = NULL;
614 memory_bflush (bfd *abfd ATTRIBUTE_UNUSED)
620 memory_bstat (bfd *abfd, struct stat *statbuf)
622 struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
624 memset (statbuf, 0, sizeof (*statbuf));
625 statbuf->st_size = bim->size;
631 memory_bmmap (bfd *abfd ATTRIBUTE_UNUSED, void *addr ATTRIBUTE_UNUSED,
632 bfd_size_type len ATTRIBUTE_UNUSED, int prot ATTRIBUTE_UNUSED,
633 int flags ATTRIBUTE_UNUSED, file_ptr offset ATTRIBUTE_UNUSED,
634 void **map_addr ATTRIBUTE_UNUSED,
635 bfd_size_type *map_len ATTRIBUTE_UNUSED)
640 const struct bfd_iovec _bfd_memory_iovec =
642 &memory_bread, &memory_bwrite, &memory_btell, &memory_bseek,
643 &memory_bclose, &memory_bflush, &memory_bstat, &memory_bmmap