1 /* Low-level I/O routines for BFDs.
3 Copyright (C) 1990-2017 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
)
181 /* If this is an archive element, don't read past the end of
183 if (abfd
->arelt_data
!= NULL
)
185 bfd_size_type maxbytes
= arelt_size (abfd
);
187 if (abfd
->where
+ size
> maxbytes
)
189 if (abfd
->where
>= maxbytes
)
191 size
= maxbytes
- abfd
->where
;
196 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
199 if (nread
!= (size_t) -1)
200 abfd
->where
+= nread
;
206 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
211 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
215 if (nwrote
!= (size_t) -1)
216 abfd
->where
+= nwrote
;
222 bfd_set_error (bfd_error_system_call
);
234 bfd
*parent_bfd
= abfd
;
235 ptr
= abfd
->iovec
->btell (abfd
);
237 while (parent_bfd
->my_archive
!= NULL
238 && !bfd_is_thin_archive (parent_bfd
->my_archive
))
240 ptr
-= parent_bfd
->origin
;
241 parent_bfd
= parent_bfd
->my_archive
;
252 bfd_flush (bfd
*abfd
)
255 return abfd
->iovec
->bflush (abfd
);
259 /* Returns 0 for success, negative value for failure (in which case
260 bfd_get_error can retrieve the error code). */
262 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
267 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
272 bfd_set_error (bfd_error_system_call
);
276 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
277 can retrieve the error code). */
280 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
283 file_ptr file_position
;
284 /* For the time being, a BFD may not seek to it's end. The problem
285 is that we don't easily have a way to recognize the end of an
286 element in an archive. */
288 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
290 if (direction
== SEEK_CUR
&& position
== 0)
293 if (abfd
->my_archive
== NULL
|| bfd_is_thin_archive (abfd
->my_archive
))
295 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
300 /* We need something smarter to optimize access to archives.
301 Currently, anything inside an archive is read via the file
302 handle for the archive. Which means that a bfd_seek on one
303 component affects the `current position' in the archive, as
304 well as in any other component.
306 It might be sufficient to put a spike through the cache
307 abstraction, and look to the archive for the file position,
308 but I think we should try for something cleaner.
310 In the meantime, no optimization for archives. */
313 file_position
= position
;
314 if (direction
== SEEK_SET
)
316 bfd
*parent_bfd
= abfd
;
318 while (parent_bfd
->my_archive
!= NULL
319 && !bfd_is_thin_archive (parent_bfd
->my_archive
))
321 file_position
+= parent_bfd
->origin
;
322 parent_bfd
= parent_bfd
->my_archive
;
327 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
333 int hold_errno
= errno
;
335 /* Force redetermination of `where' field. */
338 /* An EINVAL error probably means that the file offset was
340 if (hold_errno
== EINVAL
)
341 bfd_set_error (bfd_error_file_truncated
);
344 bfd_set_error (bfd_error_system_call
);
350 /* Adjust `where' field. */
351 if (direction
== SEEK_SET
)
352 abfd
->where
= position
;
354 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 (abfd
->iovec
== NULL
)
383 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
386 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
395 ufile_ptr bfd_get_size (bfd *abfd);
398 Return the file size (as read from file system) for the file
399 associated with BFD @var{abfd}.
401 The initial motivation for, and use of, this routine is not
402 so we can get the exact size of the object the BFD applies to, since
403 that might not be generally possible (archive members for example).
404 It would be ideal if someone could eventually modify
405 it so that such results were guaranteed.
407 Instead, we want to ask questions like "is this NNN byte sized
408 object I'm about to try read from file offset YYY reasonable?"
409 As as example of where we might do this, some object formats
410 use string tables for which the first <<sizeof (long)>> bytes of the
411 table contain the size of the table itself, including the size bytes.
412 If an application tries to read what it thinks is one of these
413 string tables, without some way to validate the size, and for
414 some reason the size is wrong (byte swapping error, wrong location
415 for the string table, etc.), the only clue is likely to be a read
416 error when it tries to read the table, or a "virtual memory
417 exhausted" error when it tries to allocate 15 bazillon bytes
418 of space for the 15 bazillon byte table it is about to read.
419 This function at least allows us to answer the question, "is the
424 bfd_get_size (bfd
*abfd
)
428 if (abfd
->iovec
== NULL
)
431 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
442 ufile_ptr bfd_get_file_size (bfd *abfd);
445 Return the file size (as read from file system) for the file
446 associated with BFD @var{abfd}. It supports both normal files
447 and archive elements.
452 bfd_get_file_size (bfd
*abfd
)
454 if (abfd
->my_archive
!= NULL
455 && !bfd_is_thin_archive (abfd
->my_archive
))
456 return arelt_size (abfd
);
458 return bfd_get_size (abfd
);
466 void *bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
467 int prot, int flags, file_ptr offset,
468 void **map_addr, bfd_size_type *map_len);
471 Return mmap()ed region of the file, if possible and implemented.
472 LEN and OFFSET do not need to be page aligned. The page aligned
473 address and length are written to MAP_ADDR and MAP_LEN.
478 bfd_mmap (bfd
*abfd
, void *addr
, bfd_size_type len
,
479 int prot
, int flags
, file_ptr offset
,
480 void **map_addr
, bfd_size_type
*map_len
)
482 void *ret
= (void *)-1;
484 if (abfd
->iovec
== NULL
)
487 return abfd
->iovec
->bmmap (abfd
, addr
, len
, prot
, flags
, offset
,
491 /* Memory file I/O operations. */
494 memory_bread (bfd
*abfd
, void *ptr
, file_ptr size
)
496 struct bfd_in_memory
*bim
;
499 bim
= (struct bfd_in_memory
*) abfd
->iostream
;
501 if (abfd
->where
+ get
> bim
->size
)
503 if (bim
->size
< (bfd_size_type
) abfd
->where
)
506 get
= bim
->size
- abfd
->where
;
507 bfd_set_error (bfd_error_file_truncated
);
509 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
514 memory_bwrite (bfd
*abfd
, const void *ptr
, file_ptr size
)
516 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
518 if (abfd
->where
+ size
> bim
->size
)
520 bfd_size_type newsize
, oldsize
;
522 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
523 bim
->size
= abfd
->where
+ size
;
524 /* Round up to cut down on memory fragmentation */
525 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
526 if (newsize
> oldsize
)
528 bim
->buffer
= (bfd_byte
*) bfd_realloc_or_free (bim
->buffer
, newsize
);
529 if (bim
->buffer
== NULL
)
534 if (newsize
> bim
->size
)
535 memset (bim
->buffer
+ bim
->size
, 0, newsize
- bim
->size
);
538 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
543 memory_btell (bfd
*abfd
)
549 memory_bseek (bfd
*abfd
, file_ptr position
, int direction
)
552 struct bfd_in_memory
*bim
;
554 bim
= (struct bfd_in_memory
*) abfd
->iostream
;
556 if (direction
== SEEK_SET
)
559 nwhere
= abfd
->where
+ position
;
568 if ((bfd_size_type
)nwhere
> bim
->size
)
570 if (abfd
->direction
== write_direction
571 || abfd
->direction
== both_direction
)
573 bfd_size_type newsize
, oldsize
;
575 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
577 /* Round up to cut down on memory fragmentation */
578 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
579 if (newsize
> oldsize
)
581 bim
->buffer
= (bfd_byte
*) bfd_realloc_or_free (bim
->buffer
, newsize
);
582 if (bim
->buffer
== NULL
)
588 memset (bim
->buffer
+ oldsize
, 0, newsize
- oldsize
);
593 abfd
->where
= bim
->size
;
595 bfd_set_error (bfd_error_file_truncated
);
603 memory_bclose (struct bfd
*abfd
)
605 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
607 if (bim
->buffer
!= NULL
)
610 abfd
->iostream
= NULL
;
616 memory_bflush (bfd
*abfd ATTRIBUTE_UNUSED
)
622 memory_bstat (bfd
*abfd
, struct stat
*statbuf
)
624 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
626 memset (statbuf
, 0, sizeof (*statbuf
));
627 statbuf
->st_size
= bim
->size
;
633 memory_bmmap (bfd
*abfd ATTRIBUTE_UNUSED
, void *addr ATTRIBUTE_UNUSED
,
634 bfd_size_type len ATTRIBUTE_UNUSED
, int prot ATTRIBUTE_UNUSED
,
635 int flags ATTRIBUTE_UNUSED
, file_ptr offset ATTRIBUTE_UNUSED
,
636 void **map_addr ATTRIBUTE_UNUSED
,
637 bfd_size_type
*map_len ATTRIBUTE_UNUSED
)
642 const struct bfd_iovec _bfd_memory_iovec
=
644 &memory_bread
, &memory_bwrite
, &memory_btell
, &memory_bseek
,
645 &memory_bclose
, &memory_bflush
, &memory_bstat
, &memory_bmmap