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 /* Attribute found - rebuild modes. */
106 size_t modes_len
= vms_attr
- modes
;
108 BFD_ASSERT (modes_len
< sizeof (vms_modes
));
109 memcpy (vms_modes
, modes
, modes_len
);
110 vms_modes
[modes_len
] = 0;
111 return close_on_exec (fopen (filename
, vms_modes
, vms_attr
+ 1));
114 #if defined (HAVE_FOPEN64)
115 return close_on_exec (fopen64 (filename
, modes
));
117 return close_on_exec (fopen (filename
, modes
));
128 The <<struct bfd_iovec>> contains the internal file I/O class.
129 Each <<BFD>> has an instance of this class and all file I/O is
130 routed through it (it is assumed that the instance implements
131 all methods listed below).
135 . {* To avoid problems with macros, a "b" rather than "f"
136 . prefix is prepended to each method name. *}
137 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
138 . bytes starting at PTR. Return the number of bytes actually
139 . transfered (a read past end-of-file returns less than NBYTES),
140 . or -1 (setting <<bfd_error>>) if an error occurs. *}
141 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
142 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
144 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
145 . if an error occurs. *}
146 . file_ptr (*btell) (struct bfd *abfd);
147 . {* For the following, on successful completion a value of 0 is returned.
148 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
149 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
150 . int (*bclose) (struct bfd *abfd);
151 . int (*bflush) (struct bfd *abfd);
152 . int (*bstat) (struct bfd *abfd, struct stat *sb);
158 /* Return value is amount read. */
161 bfd_bread (void *ptr
, bfd_size_type size
, bfd
*abfd
)
165 /* If this is an archive element, don't read past the end of
167 if (abfd
->arelt_data
!= NULL
)
169 size_t maxbytes
= ((struct areltdata
*) abfd
->arelt_data
)->parsed_size
;
174 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
176 struct bfd_in_memory
*bim
;
179 bim
= abfd
->iostream
;
181 if (abfd
->where
+ get
> bim
->size
)
183 if (bim
->size
< (bfd_size_type
) abfd
->where
)
186 get
= bim
->size
- abfd
->where
;
187 bfd_set_error (bfd_error_file_truncated
);
189 memcpy (ptr
, bim
->buffer
+ abfd
->where
, (size_t) get
);
195 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
198 if (nread
!= (size_t) -1)
199 abfd
->where
+= nread
;
205 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
209 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
211 struct bfd_in_memory
*bim
= abfd
->iostream
;
213 size
= (size_t) size
;
214 if (abfd
->where
+ size
> bim
->size
)
216 bfd_size_type newsize
, oldsize
;
218 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
219 bim
->size
= abfd
->where
+ size
;
220 /* Round up to cut down on memory fragmentation */
221 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
222 if (newsize
> oldsize
)
224 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
225 if (bim
->buffer
== NULL
)
232 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
238 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
242 if (nwrote
!= (size_t) -1)
243 abfd
->where
+= nwrote
;
249 bfd_set_error (bfd_error_system_call
);
259 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
264 ptr
= abfd
->iovec
->btell (abfd
);
266 if (abfd
->my_archive
)
277 bfd_flush (bfd
*abfd
)
279 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
283 return abfd
->iovec
->bflush (abfd
);
287 /* Returns 0 for success, negative value for failure (in which case
288 bfd_get_error can retrieve the error code). */
290 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
294 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
298 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
303 bfd_set_error (bfd_error_system_call
);
307 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
308 can retrieve the error code). */
311 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
314 file_ptr file_position
;
315 /* For the time being, a BFD may not seek to it's end. The problem
316 is that we don't easily have a way to recognize the end of an
317 element in an archive. */
319 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
321 if (direction
== SEEK_CUR
&& position
== 0)
324 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
326 struct bfd_in_memory
*bim
;
328 bim
= abfd
->iostream
;
330 if (direction
== SEEK_SET
)
331 abfd
->where
= position
;
333 abfd
->where
+= position
;
335 if (abfd
->where
> bim
->size
)
337 if ((abfd
->direction
== write_direction
) ||
338 (abfd
->direction
== both_direction
))
340 bfd_size_type newsize
, oldsize
;
342 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
343 bim
->size
= abfd
->where
;
344 /* Round up to cut down on memory fragmentation */
345 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
346 if (newsize
> oldsize
)
348 bim
->buffer
= bfd_realloc_or_free (bim
->buffer
, newsize
);
349 if (bim
->buffer
== NULL
)
358 abfd
->where
= bim
->size
;
359 bfd_set_error (bfd_error_file_truncated
);
366 if (abfd
->format
!= bfd_archive
&& abfd
->my_archive
== 0)
368 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
373 /* We need something smarter to optimize access to archives.
374 Currently, anything inside an archive is read via the file
375 handle for the archive. Which means that a bfd_seek on one
376 component affects the `current position' in the archive, as
377 well as in any other component.
379 It might be sufficient to put a spike through the cache
380 abstraction, and look to the archive for the file position,
381 but I think we should try for something cleaner.
383 In the meantime, no optimization for archives. */
386 file_position
= position
;
387 if (direction
== SEEK_SET
&& abfd
->my_archive
!= NULL
)
388 file_position
+= abfd
->origin
;
391 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
397 int hold_errno
= errno
;
399 /* Force redetermination of `where' field. */
402 /* An EINVAL error probably means that the file offset was
404 if (hold_errno
== EINVAL
)
405 bfd_set_error (bfd_error_file_truncated
);
408 bfd_set_error (bfd_error_system_call
);
414 /* Adjust `where' field. */
415 if (direction
== SEEK_SET
)
416 abfd
->where
= position
;
418 abfd
->where
+= position
;
428 long bfd_get_mtime (bfd *abfd);
431 Return the file modification time (as read from the file system, or
432 from the archive header for archive members).
437 bfd_get_mtime (bfd
*abfd
)
444 if (abfd
->iovec
== NULL
)
447 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
450 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
459 file_ptr bfd_get_size (bfd *abfd);
462 Return the file size (as read from file system) for the file
463 associated with BFD @var{abfd}.
465 The initial motivation for, and use of, this routine is not
466 so we can get the exact size of the object the BFD applies to, since
467 that might not be generally possible (archive members for example).
468 It would be ideal if someone could eventually modify
469 it so that such results were guaranteed.
471 Instead, we want to ask questions like "is this NNN byte sized
472 object I'm about to try read from file offset YYY reasonable?"
473 As as example of where we might do this, some object formats
474 use string tables for which the first <<sizeof (long)>> bytes of the
475 table contain the size of the table itself, including the size bytes.
476 If an application tries to read what it thinks is one of these
477 string tables, without some way to validate the size, and for
478 some reason the size is wrong (byte swapping error, wrong location
479 for the string table, etc.), the only clue is likely to be a read
480 error when it tries to read the table, or a "virtual memory
481 exhausted" error when it tries to allocate 15 bazillon bytes
482 of space for the 15 bazillon byte table it is about to read.
483 This function at least allows us to answer the question, "is the
488 bfd_get_size (bfd
*abfd
)
492 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
493 return ((struct bfd_in_memory
*) abfd
->iostream
)->size
;
495 if (abfd
->iovec
== NULL
)
498 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
This page took 0.040242 seconds and 4 git commands to generate.