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. */
42 real_ftell (FILE *file
)
44 #if defined (HAVE_FTELLO64)
45 return ftello64 (file
);
46 #elif defined (HAVE_FTELLO)
54 real_fseek (FILE *file
, file_ptr offset
, int whence
)
56 #if defined (HAVE_FSEEKO64)
57 return fseeko64 (file
, offset
, whence
);
58 #elif defined (HAVE_FSEEKO)
59 return fseeko (file
, offset
, whence
);
61 return fseek (file
, offset
, whence
);
66 real_fopen (const char *filename
, const char *modes
)
68 #if defined (HAVE_FOPEN64)
69 return fopen64 (filename
, modes
);
71 return fopen (filename
, modes
);
81 The <<struct bfd_iovec>> contains the internal file I/O class.
82 Each <<BFD>> has an instance of this class and all file I/O is
83 routed through it (it is assumed that the instance implements
84 all methods listed below).
88 . {* To avoid problems with macros, a "b" rather than "f"
89 . prefix is prepended to each method name. *}
90 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
91 . bytes starting at PTR. Return the number of bytes actually
92 . transfered (a read past end-of-file returns less than NBYTES),
93 . or -1 (setting <<bfd_error>>) if an error occurs. *}
94 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
95 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
97 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
98 . if an error occurs. *}
99 . file_ptr (*btell) (struct bfd *abfd);
100 . {* For the following, on successful completion a value of 0 is returned.
101 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
102 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
103 . int (*bclose) (struct bfd *abfd);
104 . int (*bflush) (struct bfd *abfd);
105 . int (*bstat) (struct bfd *abfd, struct stat *sb);
111 /* Return value is amount read. */
114 bfd_bread (void *ptr
, bfd_size_type size
, bfd
*abfd
)
118 /* If this is an archive element, don't read past the end of
120 if (abfd
->arelt_data
!= NULL
)
122 size_t maxbytes
= ((struct areltdata
*) abfd
->arelt_data
)->parsed_size
;
127 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
129 struct bfd_in_memory
*bim
;
132 bim
= abfd
->iostream
;
134 if (abfd
->where
+ get
> bim
->size
)
136 if (bim
->size
< (bfd_size_type
) abfd
->where
)
139 get
= bim
->size
- abfd
->where
;
140 bfd_set_error (bfd_error_file_truncated
);
142 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
148 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
151 if (nread
!= (size_t) -1)
152 abfd
->where
+= nread
;
158 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
162 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
164 struct bfd_in_memory
*bim
= abfd
->iostream
;
166 size
= (size_t) size
;
167 if (abfd
->where
+ size
> bim
->size
)
169 bfd_size_type newsize
, oldsize
;
171 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
172 bim
->size
= abfd
->where
+ size
;
173 /* Round up to cut down on memory fragmentation */
174 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
175 if (newsize
> oldsize
)
177 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
178 if (bim
->buffer
== NULL
)
185 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
191 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
195 if (nwrote
!= (size_t) -1)
196 abfd
->where
+= nwrote
;
202 bfd_set_error (bfd_error_system_call
);
212 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
217 ptr
= abfd
->iovec
->btell (abfd
);
219 if (abfd
->my_archive
)
230 bfd_flush (bfd
*abfd
)
232 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
236 return abfd
->iovec
->bflush (abfd
);
240 /* Returns 0 for success, negative value for failure (in which case
241 bfd_get_error can retrieve the error code). */
243 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
247 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
251 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
256 bfd_set_error (bfd_error_system_call
);
260 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
261 can retrieve the error code). */
264 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
267 file_ptr file_position
;
268 /* For the time being, a BFD may not seek to it's end. The problem
269 is that we don't easily have a way to recognize the end of an
270 element in an archive. */
272 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
274 if (direction
== SEEK_CUR
&& position
== 0)
277 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
279 struct bfd_in_memory
*bim
;
281 bim
= abfd
->iostream
;
283 if (direction
== SEEK_SET
)
284 abfd
->where
= position
;
286 abfd
->where
+= position
;
288 if (abfd
->where
> bim
->size
)
290 if ((abfd
->direction
== write_direction
) ||
291 (abfd
->direction
== both_direction
))
293 bfd_size_type newsize
, oldsize
;
295 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
296 bim
->size
= abfd
->where
;
297 /* Round up to cut down on memory fragmentation */
298 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
299 if (newsize
> oldsize
)
301 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
302 if (bim
->buffer
== NULL
)
311 abfd
->where
= bim
->size
;
312 bfd_set_error (bfd_error_file_truncated
);
319 if (abfd
->format
!= bfd_archive
&& abfd
->my_archive
== 0)
321 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
326 /* We need something smarter to optimize access to archives.
327 Currently, anything inside an archive is read via the file
328 handle for the archive. Which means that a bfd_seek on one
329 component affects the `current position' in the archive, as
330 well as in any other component.
332 It might be sufficient to put a spike through the cache
333 abstraction, and look to the archive for the file position,
334 but I think we should try for something cleaner.
336 In the meantime, no optimization for archives. */
339 file_position
= position
;
340 if (direction
== SEEK_SET
&& abfd
->my_archive
!= NULL
)
341 file_position
+= abfd
->origin
;
344 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
350 int hold_errno
= errno
;
352 /* Force redetermination of `where' field. */
355 /* An EINVAL error probably means that the file offset was
357 if (hold_errno
== EINVAL
)
358 bfd_set_error (bfd_error_file_truncated
);
361 bfd_set_error (bfd_error_system_call
);
367 /* Adjust `where' field. */
368 if (direction
== SEEK_SET
)
369 abfd
->where
= position
;
371 abfd
->where
+= position
;
381 long bfd_get_mtime (bfd *abfd);
384 Return the file modification time (as read from the file system, or
385 from the archive header for archive members).
390 bfd_get_mtime (bfd
*abfd
)
397 if (abfd
->iovec
== NULL
)
400 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
403 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
412 file_ptr bfd_get_size (bfd *abfd);
415 Return the file size (as read from file system) for the file
416 associated with BFD @var{abfd}.
418 The initial motivation for, and use of, this routine is not
419 so we can get the exact size of the object the BFD applies to, since
420 that might not be generally possible (archive members for example).
421 It would be ideal if someone could eventually modify
422 it so that such results were guaranteed.
424 Instead, we want to ask questions like "is this NNN byte sized
425 object I'm about to try read from file offset YYY reasonable?"
426 As as example of where we might do this, some object formats
427 use string tables for which the first <<sizeof (long)>> bytes of the
428 table contain the size of the table itself, including the size bytes.
429 If an application tries to read what it thinks is one of these
430 string tables, without some way to validate the size, and for
431 some reason the size is wrong (byte swapping error, wrong location
432 for the string table, etc.), the only clue is likely to be a read
433 error when it tries to read the table, or a "virtual memory
434 exhausted" error when it tries to allocate 15 bazillon bytes
435 of space for the 15 bazillon byte table it is about to read.
436 This function at least allows us to answer the question, "is the
441 bfd_get_size (bfd
*abfd
)
445 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
446 return ((struct bfd_in_memory
*) abfd
->iostream
)->size
;
448 if (abfd
->iovec
== NULL
)
451 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
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