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
)
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);
166 /* Return value is amount read. */
169 bfd_bread (void *ptr
, bfd_size_type size
, bfd
*abfd
)
173 /* If this is an archive element, don't read past the end of
175 if (abfd
->arelt_data
!= NULL
)
177 size_t maxbytes
= ((struct areltdata
*) abfd
->arelt_data
)->parsed_size
;
182 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
184 struct bfd_in_memory
*bim
;
187 bim
= abfd
->iostream
;
189 if (abfd
->where
+ get
> bim
->size
)
191 if (bim
->size
< (bfd_size_type
) abfd
->where
)
194 get
= bim
->size
- abfd
->where
;
195 bfd_set_error (bfd_error_file_truncated
);
197 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
203 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
206 if (nread
!= (size_t) -1)
207 abfd
->where
+= nread
;
213 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
217 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
219 struct bfd_in_memory
*bim
= abfd
->iostream
;
221 size
= (size_t) size
;
222 if (abfd
->where
+ size
> bim
->size
)
224 bfd_size_type newsize
, oldsize
;
226 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
227 bim
->size
= abfd
->where
+ size
;
228 /* Round up to cut down on memory fragmentation */
229 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
230 if (newsize
> oldsize
)
232 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
233 if (bim
->buffer
== NULL
)
240 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
246 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
250 if (nwrote
!= (size_t) -1)
251 abfd
->where
+= nwrote
;
257 bfd_set_error (bfd_error_system_call
);
267 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
272 ptr
= abfd
->iovec
->btell (abfd
);
274 if (abfd
->my_archive
)
285 bfd_flush (bfd
*abfd
)
287 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
291 return abfd
->iovec
->bflush (abfd
);
295 /* Returns 0 for success, negative value for failure (in which case
296 bfd_get_error can retrieve the error code). */
298 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
302 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
306 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
311 bfd_set_error (bfd_error_system_call
);
315 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
316 can retrieve the error code). */
319 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
322 file_ptr file_position
;
323 /* For the time being, a BFD may not seek to it's end. The problem
324 is that we don't easily have a way to recognize the end of an
325 element in an archive. */
327 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
329 if (direction
== SEEK_CUR
&& position
== 0)
332 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
334 struct bfd_in_memory
*bim
;
336 bim
= abfd
->iostream
;
338 if (direction
== SEEK_SET
)
339 abfd
->where
= position
;
341 abfd
->where
+= position
;
343 if (abfd
->where
> bim
->size
)
345 if ((abfd
->direction
== write_direction
) ||
346 (abfd
->direction
== both_direction
))
348 bfd_size_type newsize
, oldsize
;
350 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
351 bim
->size
= abfd
->where
;
352 /* Round up to cut down on memory fragmentation */
353 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
354 if (newsize
> oldsize
)
356 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
357 if (bim
->buffer
== NULL
)
366 abfd
->where
= bim
->size
;
367 bfd_set_error (bfd_error_file_truncated
);
374 if (abfd
->format
!= bfd_archive
&& abfd
->my_archive
== 0)
376 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
381 /* We need something smarter to optimize access to archives.
382 Currently, anything inside an archive is read via the file
383 handle for the archive. Which means that a bfd_seek on one
384 component affects the `current position' in the archive, as
385 well as in any other component.
387 It might be sufficient to put a spike through the cache
388 abstraction, and look to the archive for the file position,
389 but I think we should try for something cleaner.
391 In the meantime, no optimization for archives. */
394 file_position
= position
;
395 if (direction
== SEEK_SET
&& abfd
->my_archive
!= NULL
)
396 file_position
+= abfd
->origin
;
399 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
405 int hold_errno
= errno
;
407 /* Force redetermination of `where' field. */
410 /* An EINVAL error probably means that the file offset was
412 if (hold_errno
== EINVAL
)
413 bfd_set_error (bfd_error_file_truncated
);
416 bfd_set_error (bfd_error_system_call
);
422 /* Adjust `where' field. */
423 if (direction
== SEEK_SET
)
424 abfd
->where
= position
;
426 abfd
->where
+= position
;
436 long bfd_get_mtime (bfd *abfd);
439 Return the file modification time (as read from the file system, or
440 from the archive header for archive members).
445 bfd_get_mtime (bfd
*abfd
)
452 if (abfd
->iovec
== NULL
)
455 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
458 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
467 file_ptr bfd_get_size (bfd *abfd);
470 Return the file size (as read from file system) for the file
471 associated with BFD @var{abfd}.
473 The initial motivation for, and use of, this routine is not
474 so we can get the exact size of the object the BFD applies to, since
475 that might not be generally possible (archive members for example).
476 It would be ideal if someone could eventually modify
477 it so that such results were guaranteed.
479 Instead, we want to ask questions like "is this NNN byte sized
480 object I'm about to try read from file offset YYY reasonable?"
481 As as example of where we might do this, some object formats
482 use string tables for which the first <<sizeof (long)>> bytes of the
483 table contain the size of the table itself, including the size bytes.
484 If an application tries to read what it thinks is one of these
485 string tables, without some way to validate the size, and for
486 some reason the size is wrong (byte swapping error, wrong location
487 for the string table, etc.), the only clue is likely to be a read
488 error when it tries to read the table, or a "virtual memory
489 exhausted" error when it tries to allocate 15 bazillon bytes
490 of space for the 15 bazillon byte table it is about to read.
491 This function at least allows us to answer the question, "is the
496 bfd_get_size (bfd
*abfd
)
500 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
501 return ((struct bfd_in_memory
*) abfd
->iostream
)->size
;
503 if (abfd
->iovec
== NULL
)
506 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
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