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
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 2 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, MA 02110-1301, USA. */
31 #define S_IXUSR 0100 /* Execute by owner. */
34 #define S_IXGRP 0010 /* Execute by group. */
37 #define S_IXOTH 0001 /* Execute by others. */
41 real_ftell (FILE *file
)
43 #if defined (HAVE_FTELLO64)
44 return ftello64 (file
);
45 #elif defined (HAVE_FTELLO)
53 real_fseek (FILE *file
, file_ptr offset
, int whence
)
55 #if defined (HAVE_FSEEKO64)
56 return fseeko64 (file
, offset
, whence
);
57 #elif defined (HAVE_FSEEKO)
58 return fseeko (file
, offset
, whence
);
60 return fseek (file
, offset
, whence
);
65 real_fopen (const char *filename
, const char *modes
)
67 #if defined (HAVE_FOPEN64)
68 return fopen64 (filename
, modes
);
70 return fopen (filename
, modes
);
80 The <<struct bfd_iovec>> contains the internal file I/O class.
81 Each <<BFD>> has an instance of this class and all file I/O is
82 routed through it (it is assumed that the instance implements
83 all methods listed below).
87 . {* To avoid problems with macros, a "b" rather than "f"
88 . prefix is prepended to each method name. *}
89 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
90 . bytes starting at PTR. Return the number of bytes actually
91 . transfered (a read past end-of-file returns less than NBYTES),
92 . or -1 (setting <<bfd_error>>) if an error occurs. *}
93 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
94 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
96 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
97 . if an error occurs. *}
98 . file_ptr (*btell) (struct bfd *abfd);
99 . {* For the following, on successful completion a value of 0 is returned.
100 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
101 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
102 . int (*bclose) (struct bfd *abfd);
103 . int (*bflush) (struct bfd *abfd);
104 . int (*bstat) (struct bfd *abfd, struct stat *sb);
110 /* Return value is amount read. */
113 bfd_bread (void *ptr
, bfd_size_type size
, bfd
*abfd
)
117 /* If this is an archive element, don't read past the end of
119 if (abfd
->arelt_data
!= NULL
)
121 size_t maxbytes
= ((struct areltdata
*) abfd
->arelt_data
)->parsed_size
;
126 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
128 struct bfd_in_memory
*bim
;
131 bim
= abfd
->iostream
;
133 if (abfd
->where
+ get
> bim
->size
)
135 if (bim
->size
< (bfd_size_type
) abfd
->where
)
138 get
= bim
->size
- abfd
->where
;
139 bfd_set_error (bfd_error_file_truncated
);
141 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
147 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
150 if (nread
!= (size_t) -1)
151 abfd
->where
+= nread
;
157 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
161 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
163 struct bfd_in_memory
*bim
= abfd
->iostream
;
165 size
= (size_t) size
;
166 if (abfd
->where
+ size
> bim
->size
)
168 bfd_size_type newsize
, oldsize
;
170 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
171 bim
->size
= abfd
->where
+ size
;
172 /* Round up to cut down on memory fragmentation */
173 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
174 if (newsize
> oldsize
)
176 bim
->buffer
= bfd_realloc (bim
->buffer
, newsize
);
177 if (bim
->buffer
== 0)
184 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
190 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
194 if (nwrote
!= (size_t) -1)
195 abfd
->where
+= nwrote
;
201 bfd_set_error (bfd_error_system_call
);
211 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
216 ptr
= abfd
->iovec
->btell (abfd
);
218 if (abfd
->my_archive
)
229 bfd_flush (bfd
*abfd
)
231 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
235 return abfd
->iovec
->bflush (abfd
);
239 /* Returns 0 for success, negative value for failure (in which case
240 bfd_get_error can retrieve the error code). */
242 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
246 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
250 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
255 bfd_set_error (bfd_error_system_call
);
259 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
260 can retrieve the error code). */
263 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
266 file_ptr file_position
;
267 /* For the time being, a BFD may not seek to it's end. The problem
268 is that we don't easily have a way to recognize the end of an
269 element in an archive. */
271 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
273 if (direction
== SEEK_CUR
&& position
== 0)
276 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
278 struct bfd_in_memory
*bim
;
280 bim
= abfd
->iostream
;
282 if (direction
== SEEK_SET
)
283 abfd
->where
= position
;
285 abfd
->where
+= position
;
287 if (abfd
->where
> bim
->size
)
289 if ((abfd
->direction
== write_direction
) ||
290 (abfd
->direction
== both_direction
))
292 bfd_size_type newsize
, oldsize
;
294 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
295 bim
->size
= abfd
->where
;
296 /* Round up to cut down on memory fragmentation */
297 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
298 if (newsize
> oldsize
)
300 bim
->buffer
= bfd_realloc (bim
->buffer
, newsize
);
301 if (bim
->buffer
== 0)
310 abfd
->where
= bim
->size
;
311 bfd_set_error (bfd_error_file_truncated
);
318 if (abfd
->format
!= bfd_archive
&& abfd
->my_archive
== 0)
320 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
325 /* We need something smarter to optimize access to archives.
326 Currently, anything inside an archive is read via the file
327 handle for the archive. Which means that a bfd_seek on one
328 component affects the `current position' in the archive, as
329 well as in any other component.
331 It might be sufficient to put a spike through the cache
332 abstraction, and look to the archive for the file position,
333 but I think we should try for something cleaner.
335 In the meantime, no optimization for archives. */
338 file_position
= position
;
339 if (direction
== SEEK_SET
&& abfd
->my_archive
!= NULL
)
340 file_position
+= abfd
->origin
;
343 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
349 int hold_errno
= errno
;
351 /* Force redetermination of `where' field. */
354 /* An EINVAL error probably means that the file offset was
356 if (hold_errno
== EINVAL
)
357 bfd_set_error (bfd_error_file_truncated
);
360 bfd_set_error (bfd_error_system_call
);
366 /* Adjust `where' field. */
367 if (direction
== SEEK_SET
)
368 abfd
->where
= position
;
370 abfd
->where
+= position
;
380 long bfd_get_mtime (bfd *abfd);
383 Return the file modification time (as read from the file system, or
384 from the archive header for archive members).
389 bfd_get_mtime (bfd
*abfd
)
396 if (abfd
->iovec
== NULL
)
399 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
402 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
411 file_ptr bfd_get_size (bfd *abfd);
414 Return the file size (as read from file system) for the file
415 associated with BFD @var{abfd}.
417 The initial motivation for, and use of, this routine is not
418 so we can get the exact size of the object the BFD applies to, since
419 that might not be generally possible (archive members for example).
420 It would be ideal if someone could eventually modify
421 it so that such results were guaranteed.
423 Instead, we want to ask questions like "is this NNN byte sized
424 object I'm about to try read from file offset YYY reasonable?"
425 As as example of where we might do this, some object formats
426 use string tables for which the first <<sizeof (long)>> bytes of the
427 table contain the size of the table itself, including the size bytes.
428 If an application tries to read what it thinks is one of these
429 string tables, without some way to validate the size, and for
430 some reason the size is wrong (byte swapping error, wrong location
431 for the string table, etc.), the only clue is likely to be a read
432 error when it tries to read the table, or a "virtual memory
433 exhausted" error when it tries to allocate 15 bazillon bytes
434 of space for the 15 bazillon byte table it is about to read.
435 This function at least allows us to answer the question, "is the
440 bfd_get_size (bfd
*abfd
)
444 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
445 return ((struct bfd_in_memory
*) abfd
->iostream
)->size
;
447 if (abfd
->iovec
== NULL
)
450 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)