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
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
)
89 #if defined (HAVE_FOPEN64)
90 return close_on_exec (fopen64 (filename
, modes
));
92 return close_on_exec (fopen (filename
, modes
));
102 The <<struct bfd_iovec>> contains the internal file I/O class.
103 Each <<BFD>> has an instance of this class and all file I/O is
104 routed through it (it is assumed that the instance implements
105 all methods listed below).
109 . {* To avoid problems with macros, a "b" rather than "f"
110 . prefix is prepended to each method name. *}
111 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
112 . bytes starting at PTR. Return the number of bytes actually
113 . transfered (a read past end-of-file returns less than NBYTES),
114 . or -1 (setting <<bfd_error>>) if an error occurs. *}
115 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
116 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
118 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
119 . if an error occurs. *}
120 . file_ptr (*btell) (struct bfd *abfd);
121 . {* For the following, on successful completion a value of 0 is returned.
122 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
123 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
124 . int (*bclose) (struct bfd *abfd);
125 . int (*bflush) (struct bfd *abfd);
126 . int (*bstat) (struct bfd *abfd, struct stat *sb);
132 /* Return value is amount read. */
135 bfd_bread (void *ptr
, bfd_size_type size
, bfd
*abfd
)
139 /* If this is an archive element, don't read past the end of
141 if (abfd
->arelt_data
!= NULL
)
143 size_t maxbytes
= ((struct areltdata
*) abfd
->arelt_data
)->parsed_size
;
148 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
150 struct bfd_in_memory
*bim
;
153 bim
= abfd
->iostream
;
155 if (abfd
->where
+ get
> bim
->size
)
157 if (bim
->size
< (bfd_size_type
) abfd
->where
)
160 get
= bim
->size
- abfd
->where
;
161 bfd_set_error (bfd_error_file_truncated
);
163 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
169 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
172 if (nread
!= (size_t) -1)
173 abfd
->where
+= nread
;
179 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
183 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
185 struct bfd_in_memory
*bim
= abfd
->iostream
;
187 size
= (size_t) size
;
188 if (abfd
->where
+ size
> bim
->size
)
190 bfd_size_type newsize
, oldsize
;
192 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
193 bim
->size
= abfd
->where
+ size
;
194 /* Round up to cut down on memory fragmentation */
195 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
196 if (newsize
> oldsize
)
198 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
199 if (bim
->buffer
== NULL
)
206 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
212 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
216 if (nwrote
!= (size_t) -1)
217 abfd
->where
+= nwrote
;
223 bfd_set_error (bfd_error_system_call
);
233 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
238 ptr
= abfd
->iovec
->btell (abfd
);
240 if (abfd
->my_archive
)
251 bfd_flush (bfd
*abfd
)
253 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
257 return abfd
->iovec
->bflush (abfd
);
261 /* Returns 0 for success, negative value for failure (in which case
262 bfd_get_error can retrieve the error code). */
264 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
268 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
272 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
277 bfd_set_error (bfd_error_system_call
);
281 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
282 can retrieve the error code). */
285 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
288 file_ptr file_position
;
289 /* For the time being, a BFD may not seek to it's end. The problem
290 is that we don't easily have a way to recognize the end of an
291 element in an archive. */
293 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
295 if (direction
== SEEK_CUR
&& position
== 0)
298 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
300 struct bfd_in_memory
*bim
;
302 bim
= abfd
->iostream
;
304 if (direction
== SEEK_SET
)
305 abfd
->where
= position
;
307 abfd
->where
+= position
;
309 if (abfd
->where
> bim
->size
)
311 if ((abfd
->direction
== write_direction
) ||
312 (abfd
->direction
== both_direction
))
314 bfd_size_type newsize
, oldsize
;
316 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
317 bim
->size
= abfd
->where
;
318 /* Round up to cut down on memory fragmentation */
319 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
320 if (newsize
> oldsize
)
322 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
323 if (bim
->buffer
== NULL
)
332 abfd
->where
= bim
->size
;
333 bfd_set_error (bfd_error_file_truncated
);
340 if (abfd
->format
!= bfd_archive
&& abfd
->my_archive
== 0)
342 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
347 /* We need something smarter to optimize access to archives.
348 Currently, anything inside an archive is read via the file
349 handle for the archive. Which means that a bfd_seek on one
350 component affects the `current position' in the archive, as
351 well as in any other component.
353 It might be sufficient to put a spike through the cache
354 abstraction, and look to the archive for the file position,
355 but I think we should try for something cleaner.
357 In the meantime, no optimization for archives. */
360 file_position
= position
;
361 if (direction
== SEEK_SET
&& abfd
->my_archive
!= NULL
)
362 file_position
+= abfd
->origin
;
365 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
371 int hold_errno
= errno
;
373 /* Force redetermination of `where' field. */
376 /* An EINVAL error probably means that the file offset was
378 if (hold_errno
== EINVAL
)
379 bfd_set_error (bfd_error_file_truncated
);
382 bfd_set_error (bfd_error_system_call
);
388 /* Adjust `where' field. */
389 if (direction
== SEEK_SET
)
390 abfd
->where
= position
;
392 abfd
->where
+= position
;
402 long bfd_get_mtime (bfd *abfd);
405 Return the file modification time (as read from the file system, or
406 from the archive header for archive members).
411 bfd_get_mtime (bfd
*abfd
)
418 if (abfd
->iovec
== NULL
)
421 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
424 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
433 file_ptr bfd_get_size (bfd *abfd);
436 Return the file size (as read from file system) for the file
437 associated with BFD @var{abfd}.
439 The initial motivation for, and use of, this routine is not
440 so we can get the exact size of the object the BFD applies to, since
441 that might not be generally possible (archive members for example).
442 It would be ideal if someone could eventually modify
443 it so that such results were guaranteed.
445 Instead, we want to ask questions like "is this NNN byte sized
446 object I'm about to try read from file offset YYY reasonable?"
447 As as example of where we might do this, some object formats
448 use string tables for which the first <<sizeof (long)>> bytes of the
449 table contain the size of the table itself, including the size bytes.
450 If an application tries to read what it thinks is one of these
451 string tables, without some way to validate the size, and for
452 some reason the size is wrong (byte swapping error, wrong location
453 for the string table, etc.), the only clue is likely to be a read
454 error when it tries to read the table, or a "virtual memory
455 exhausted" error when it tries to allocate 15 bazillon bytes
456 of space for the 15 bazillon byte table it is about to read.
457 This function at least allows us to answer the question, "is the
462 bfd_get_size (bfd
*abfd
)
466 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
467 return ((struct bfd_in_memory
*) abfd
->iostream
)->size
;
469 if (abfd
->iovec
== NULL
)
472 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
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