1 /* Low-level I/O routines for BFDs.
3 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
5 Free Software Foundation, Inc.
7 Written by Cygnus Support.
9 This file is part of BFD, the Binary File Descriptor library.
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 3 of the License, or
14 (at your option) any later version.
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24 MA 02110-1301, USA. */
32 #define S_IXUSR 0100 /* Execute by owner. */
35 #define S_IXGRP 0010 /* Execute by group. */
38 #define S_IXOTH 0001 /* Execute by others. */
46 real_ftell (FILE *file
)
48 #if defined (HAVE_FTELLO64)
49 return ftello64 (file
);
50 #elif defined (HAVE_FTELLO)
58 real_fseek (FILE *file
, file_ptr offset
, int whence
)
60 #if defined (HAVE_FSEEKO64)
61 return fseeko64 (file
, offset
, whence
);
62 #elif defined (HAVE_FSEEKO)
63 return fseeko (file
, offset
, whence
);
65 return fseek (file
, offset
, whence
);
69 /* Mark FILE as close-on-exec. Return FILE. FILE may be NULL, in
70 which case nothing is done. */
72 close_on_exec (FILE *file
)
74 #if defined (HAVE_FILENO) && defined (F_GETFD)
77 int fd
= fileno (file
);
78 int old
= fcntl (fd
, F_GETFD
, 0);
80 fcntl (fd
, F_SETFD
, old
| FD_CLOEXEC
);
87 real_fopen (const char *filename
, const char *modes
)
93 /* On VMS, fopen allows file attributes as optionnal arguments.
94 We need to use them but we'd better to use the common prototype.
95 In fopen-vms.h, they are separated from the mode with a comma.
97 vms_attr
= strchr (modes
, ',');
101 return close_on_exec (fopen (filename
, modes
));
105 /* Attributes found. Split. */
106 size_t modes_len
= strlen (modes
) + 1;
107 char attrs
[modes_len
+ 1];
111 memcpy (attrs
, modes
, modes_len
);
113 for (i
= 0; i
< 2; i
++)
115 at
[i
+ 1] = strchr (at
[i
], ',');
116 BFD_ASSERT (at
[i
+ 1] != NULL
);
117 *(at
[i
+ 1]++) = 0; /* Replace ',' with a nul, and skip it. */
119 return close_on_exec (fopen (filename
, at
[0], at
[1], at
[2]));
122 #if defined (HAVE_FOPEN64)
123 return close_on_exec (fopen64 (filename
, modes
));
125 return close_on_exec (fopen (filename
, modes
));
136 The <<struct bfd_iovec>> contains the internal file I/O class.
137 Each <<BFD>> has an instance of this class and all file I/O is
138 routed through it (it is assumed that the instance implements
139 all methods listed below).
143 . {* To avoid problems with macros, a "b" rather than "f"
144 . prefix is prepended to each method name. *}
145 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
146 . bytes starting at PTR. Return the number of bytes actually
147 . transfered (a read past end-of-file returns less than NBYTES),
148 . or -1 (setting <<bfd_error>>) if an error occurs. *}
149 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
150 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
152 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
153 . if an error occurs. *}
154 . file_ptr (*btell) (struct bfd *abfd);
155 . {* For the following, on successful completion a value of 0 is returned.
156 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
157 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
158 . int (*bclose) (struct bfd *abfd);
159 . int (*bflush) (struct bfd *abfd);
160 . int (*bstat) (struct bfd *abfd, struct stat *sb);
161 . {* Just like mmap: (void*)-1 on failure, mmapped address on success. *}
162 . void *(*bmmap) (struct bfd *abfd, void *addr, bfd_size_type len,
163 . int prot, int flags, file_ptr offset);
166 .extern const struct bfd_iovec _bfd_memory_iovec;
171 /* Return value is amount read. */
174 bfd_bread (void *ptr
, bfd_size_type size
, bfd
*abfd
)
178 /* If this is an archive element, don't read past the end of
180 if (abfd
->arelt_data
!= NULL
)
182 size_t maxbytes
= ((struct areltdata
*) abfd
->arelt_data
)->parsed_size
;
188 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
191 if (nread
!= (size_t) -1)
192 abfd
->where
+= nread
;
198 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
203 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
207 if (nwrote
!= (size_t) -1)
208 abfd
->where
+= nwrote
;
214 bfd_set_error (bfd_error_system_call
);
226 ptr
= abfd
->iovec
->btell (abfd
);
228 if (abfd
->my_archive
)
239 bfd_flush (bfd
*abfd
)
242 return abfd
->iovec
->bflush (abfd
);
246 /* Returns 0 for success, negative value for failure (in which case
247 bfd_get_error can retrieve the error code). */
249 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
254 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
259 bfd_set_error (bfd_error_system_call
);
263 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
264 can retrieve the error code). */
267 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
270 file_ptr file_position
;
271 /* For the time being, a BFD may not seek to it's end. The problem
272 is that we don't easily have a way to recognize the end of an
273 element in an archive. */
275 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
277 if (direction
== SEEK_CUR
&& position
== 0)
280 if (abfd
->format
!= bfd_archive
&& abfd
->my_archive
== 0)
282 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
287 /* We need something smarter to optimize access to archives.
288 Currently, anything inside an archive is read via the file
289 handle for the archive. Which means that a bfd_seek on one
290 component affects the `current position' in the archive, as
291 well as in any other component.
293 It might be sufficient to put a spike through the cache
294 abstraction, and look to the archive for the file position,
295 but I think we should try for something cleaner.
297 In the meantime, no optimization for archives. */
300 file_position
= position
;
301 if (direction
== SEEK_SET
&& abfd
->my_archive
!= NULL
)
302 file_position
+= abfd
->origin
;
305 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
311 int hold_errno
= errno
;
313 /* Force redetermination of `where' field. */
316 /* An EINVAL error probably means that the file offset was
318 if (hold_errno
== EINVAL
)
319 bfd_set_error (bfd_error_file_truncated
);
322 bfd_set_error (bfd_error_system_call
);
328 /* Adjust `where' field. */
329 if (direction
== SEEK_SET
)
330 abfd
->where
= position
;
332 abfd
->where
+= position
;
342 long bfd_get_mtime (bfd *abfd);
345 Return the file modification time (as read from the file system, or
346 from the archive header for archive members).
351 bfd_get_mtime (bfd
*abfd
)
358 if (abfd
->iovec
== NULL
)
361 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
364 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
373 file_ptr bfd_get_size (bfd *abfd);
376 Return the file size (as read from file system) for the file
377 associated with BFD @var{abfd}.
379 The initial motivation for, and use of, this routine is not
380 so we can get the exact size of the object the BFD applies to, since
381 that might not be generally possible (archive members for example).
382 It would be ideal if someone could eventually modify
383 it so that such results were guaranteed.
385 Instead, we want to ask questions like "is this NNN byte sized
386 object I'm about to try read from file offset YYY reasonable?"
387 As as example of where we might do this, some object formats
388 use string tables for which the first <<sizeof (long)>> bytes of the
389 table contain the size of the table itself, including the size bytes.
390 If an application tries to read what it thinks is one of these
391 string tables, without some way to validate the size, and for
392 some reason the size is wrong (byte swapping error, wrong location
393 for the string table, etc.), the only clue is likely to be a read
394 error when it tries to read the table, or a "virtual memory
395 exhausted" error when it tries to allocate 15 bazillon bytes
396 of space for the 15 bazillon byte table it is about to read.
397 This function at least allows us to answer the question, "is the
402 bfd_get_size (bfd
*abfd
)
406 if (abfd
->iovec
== NULL
)
409 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
421 void *bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
422 int prot, int flags, file_ptr offset);
425 Return mmap()ed region of the file, if possible and implemented.
430 bfd_mmap (bfd
*abfd
, void *addr
, bfd_size_type len
,
431 int prot
, int flags
, file_ptr offset
)
433 void *ret
= (void *)-1;
435 if (abfd
->iovec
== NULL
)
438 return abfd
->iovec
->bmmap (abfd
, addr
, len
, prot
, flags
, offset
);
441 /* Memory file I/O operations. */
444 memory_bread (bfd
*abfd
, void *ptr
, file_ptr size
)
446 struct bfd_in_memory
*bim
;
449 bim
= (struct bfd_in_memory
*) abfd
->iostream
;
451 if (abfd
->where
+ get
> bim
->size
)
453 if (bim
->size
< (bfd_size_type
) abfd
->where
)
456 get
= bim
->size
- abfd
->where
;
457 bfd_set_error (bfd_error_file_truncated
);
459 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
464 memory_bwrite (bfd
*abfd
, const void *ptr
, file_ptr size
)
466 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
468 if (abfd
->where
+ size
> bim
->size
)
470 bfd_size_type newsize
, oldsize
;
472 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
473 bim
->size
= abfd
->where
+ size
;
474 /* Round up to cut down on memory fragmentation */
475 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
476 if (newsize
> oldsize
)
478 bim
->buffer
= (bfd_byte
*) bfd_realloc_or_free (bim
->buffer
, newsize
);
479 if (bim
->buffer
== NULL
)
484 if (newsize
> bim
->size
)
485 memset (bim
->buffer
+ bim
->size
, 0, newsize
- bim
->size
);
488 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
493 memory_btell (bfd
*abfd
)
499 memory_bseek (bfd
*abfd
, file_ptr position
, int direction
)
502 struct bfd_in_memory
*bim
;
504 bim
= (struct bfd_in_memory
*) abfd
->iostream
;
506 if (direction
== SEEK_SET
)
509 nwhere
= abfd
->where
+ position
;
518 if ((bfd_size_type
)nwhere
> bim
->size
)
520 if (abfd
->direction
== write_direction
521 || abfd
->direction
== both_direction
)
523 bfd_size_type newsize
, oldsize
;
525 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
527 /* Round up to cut down on memory fragmentation */
528 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
529 if (newsize
> oldsize
)
531 bim
->buffer
= (bfd_byte
*) bfd_realloc_or_free (bim
->buffer
, newsize
);
532 if (bim
->buffer
== NULL
)
538 memset (bim
->buffer
+ oldsize
, 0, newsize
- oldsize
);
543 abfd
->where
= bim
->size
;
545 bfd_set_error (bfd_error_file_truncated
);
553 memory_bclose (struct bfd
*abfd
)
555 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
557 if (bim
->buffer
!= NULL
)
560 abfd
->iostream
= NULL
;
566 memory_bflush (bfd
*abfd ATTRIBUTE_UNUSED
)
572 memory_bstat (bfd
*abfd
, struct stat
*statbuf
)
574 struct bfd_in_memory
*bim
= (struct bfd_in_memory
*) abfd
->iostream
;
576 memset (statbuf
, 0, sizeof (statbuf
));
577 statbuf
->st_size
= bim
->size
;
583 memory_bmmap (bfd
*abfd ATTRIBUTE_UNUSED
, void *addr ATTRIBUTE_UNUSED
,
584 bfd_size_type len ATTRIBUTE_UNUSED
, int prot ATTRIBUTE_UNUSED
,
585 int flags ATTRIBUTE_UNUSED
, file_ptr offset ATTRIBUTE_UNUSED
)
590 const struct bfd_iovec _bfd_memory_iovec
=
592 &memory_bread
, &memory_bwrite
, &memory_btell
, &memory_bseek
,
593 &memory_bclose
, &memory_bflush
, &memory_bstat
, &memory_bmmap