1 /* Low-level I/O routines for BFDs.
3 Copyright (C) 1990-2020 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 if ((direction
== SEEK_CUR
&& position
== 0)
334 || (direction
== SEEK_SET
&& (ufile_ptr
) position
== abfd
->where
))
337 result
= abfd
->iovec
->bseek (abfd
, position
, direction
);
340 /* An EINVAL error probably means that the file offset was
343 bfd_set_error (bfd_error_file_truncated
);
345 bfd_set_error (bfd_error_system_call
);
349 /* Adjust `where' field. */
350 if (direction
== SEEK_CUR
)
351 abfd
->where
+= position
;
353 abfd
->where
= position
;
364 long bfd_get_mtime (bfd *abfd);
367 Return the file modification time (as read from the file system, or
368 from the archive header for archive members).
373 bfd_get_mtime (bfd
*abfd
)
380 if (bfd_stat (abfd
, &buf
) != 0)
383 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
392 ufile_ptr bfd_get_size (bfd *abfd);
395 Return the file size (as read from file system) for the file
396 associated with BFD @var{abfd}.
398 The initial motivation for, and use of, this routine is not
399 so we can get the exact size of the object the BFD applies to, since
400 that might not be generally possible (archive members for example).
401 It would be ideal if someone could eventually modify
402 it so that such results were guaranteed.
404 Instead, we want to ask questions like "is this NNN byte sized
405 object I'm about to try read from file offset YYY reasonable?"
406 As as example of where we might do this, some object formats
407 use string tables for which the first <<sizeof (long)>> bytes of the
408 table contain the size of the table itself, including the size bytes.
409 If an application tries to read what it thinks is one of these
410 string tables, without some way to validate the size, and for
411 some reason the size is wrong (byte swapping error, wrong location
412 for the string table, etc.), the only clue is likely to be a read
413 error when it tries to read the table, or a "virtual memory
414 exhausted" error when it tries to allocate 15 bazillon bytes
415 of space for the 15 bazillon byte table it is about to read.
416 This function at least allows us to answer the question, "is the
419 A return value of zero indicates the file size is unknown.
423 bfd_get_size (bfd
*abfd
)
425 /* A size of 0 means we haven't yet called bfd_stat. A size of 1
426 means we have a cached value of 0, ie. unknown. */
427 if (abfd
->size
<= 1 || bfd_write_p (abfd
))
431 if (abfd
->size
== 1 && !bfd_write_p (abfd
))
434 if (bfd_stat (abfd
, &buf
) != 0
436 || buf
.st_size
- (ufile_ptr
) buf
.st_size
!= 0)
441 abfd
->size
= buf
.st_size
;
451 ufile_ptr bfd_get_file_size (bfd *abfd);
454 Return the file size (as read from file system) for the file
455 associated with BFD @var{abfd}. It supports both normal files
456 and archive elements.
461 bfd_get_file_size (bfd
*abfd
)
463 if (abfd
->my_archive
!= NULL
464 && !bfd_is_thin_archive (abfd
->my_archive
))
465 return arelt_size (abfd
);
467 return bfd_get_size (abfd
);
475 void *bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
476 int prot, int flags, file_ptr offset,
477 void **map_addr, bfd_size_type *map_len);
480 Return mmap()ed region of the file, if possible and implemented.
481 LEN and OFFSET do not need to be page aligned. The page aligned
482 address and length are written to MAP_ADDR and MAP_LEN.
487 bfd_mmap (bfd
*abfd
, void *addr
, bfd_size_type len
,
488 int prot
, int flags
, file_ptr offset
,
489 void **map_addr
, bfd_size_type
*map_len
)
491 while (abfd
->my_archive
!= NULL
492 && !bfd_is_thin_archive (abfd
->my_archive
))
494 offset
+= abfd
->origin
;
495 abfd
= abfd
->my_archive
;
498 if (abfd
->iovec
== NULL
)
500 bfd_set_error (bfd_error_invalid_operation
);
504 return abfd
->iovec
->bmmap (abfd
, addr
, len
, prot
, flags
, offset
,
508 /* Memory file I/O operations. */
511 memory_bread (bfd
*abfd
, void *ptr
, file_ptr size
)
513 struct bfd_in_memory
*bim
;
516 bim
= (struct bfd_in_memory
*) abfd
->iostream
;
518 if (abfd
->where
+ get
> bim
->size
)
520 if (bim
->size
< (bfd_size_type
) abfd
->where
)
523 get
= bim
->size
- abfd
->where
;
524 bfd_set_error (bfd_error_file_truncated
);
526 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
531 memory_bwrite (bfd
*abfd
, const void *ptr
, file_ptr size
)
533 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
535 if (abfd
->where
+ size
> bim
->size
)
537 bfd_size_type newsize
, oldsize
;
539 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
540 bim
->size
= abfd
->where
+ size
;
541 /* Round up to cut down on memory fragmentation */
542 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
543 if (newsize
> oldsize
)
545 bim
->buffer
= (bfd_byte
*) bfd_realloc_or_free (bim
->buffer
, newsize
);
546 if (bim
->buffer
== NULL
)
551 if (newsize
> bim
->size
)
552 memset (bim
->buffer
+ bim
->size
, 0, newsize
- bim
->size
);
555 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
560 memory_btell (bfd
*abfd
)
566 memory_bseek (bfd
*abfd
, file_ptr position
, int direction
)
569 struct bfd_in_memory
*bim
;
571 bim
= (struct bfd_in_memory
*) abfd
->iostream
;
573 if (direction
== SEEK_SET
)
576 nwhere
= abfd
->where
+ position
;
585 if ((bfd_size_type
)nwhere
> bim
->size
)
587 if (abfd
->direction
== write_direction
588 || abfd
->direction
== both_direction
)
590 bfd_size_type newsize
, oldsize
;
592 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
594 /* Round up to cut down on memory fragmentation */
595 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
596 if (newsize
> oldsize
)
598 bim
->buffer
= (bfd_byte
*) bfd_realloc_or_free (bim
->buffer
, newsize
);
599 if (bim
->buffer
== NULL
)
605 memset (bim
->buffer
+ oldsize
, 0, newsize
- oldsize
);
610 abfd
->where
= bim
->size
;
612 bfd_set_error (bfd_error_file_truncated
);
620 memory_bclose (struct bfd
*abfd
)
622 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
624 if (bim
->buffer
!= NULL
)
627 abfd
->iostream
= NULL
;
633 memory_bflush (bfd
*abfd ATTRIBUTE_UNUSED
)
639 memory_bstat (bfd
*abfd
, struct stat
*statbuf
)
641 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
643 memset (statbuf
, 0, sizeof (*statbuf
));
644 statbuf
->st_size
= bim
->size
;
650 memory_bmmap (bfd
*abfd ATTRIBUTE_UNUSED
, void *addr ATTRIBUTE_UNUSED
,
651 bfd_size_type len ATTRIBUTE_UNUSED
, int prot ATTRIBUTE_UNUSED
,
652 int flags ATTRIBUTE_UNUSED
, file_ptr offset ATTRIBUTE_UNUSED
,
653 void **map_addr ATTRIBUTE_UNUSED
,
654 bfd_size_type
*map_len ATTRIBUTE_UNUSED
)
659 const struct bfd_iovec _bfd_memory_iovec
=
661 &memory_bread
, &memory_bwrite
, &memory_btell
, &memory_bseek
,
662 &memory_bclose
, &memory_bflush
, &memory_bstat
, &memory_bmmap