1 | /* Copyright (C) 1993-2016 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <http://www.gnu.org/licenses/>. |
17 | |
18 | As a special exception, if you link the code in this file with |
19 | files compiled with a GNU compiler to produce an executable, |
20 | that does not cause the resulting executable to be covered by |
21 | the GNU Lesser General Public License. This exception does not |
22 | however invalidate any other reasons why the executable file |
23 | might be covered by the GNU Lesser General Public License. |
24 | This exception applies to code released by its copyright holders |
25 | in files containing the exception. */ |
26 | |
27 | #include <stdlib.h> |
28 | #include <libioP.h> |
29 | #include <errno.h> |
30 | #ifndef errno |
31 | extern int errno; |
32 | #endif |
33 | #ifndef __set_errno |
34 | # define __set_errno(Val) errno = (Val) |
35 | #endif |
36 | |
37 | _IO_off64_t |
38 | _IO_seekoff_unlocked (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) |
39 | { |
40 | if (dir != _IO_seek_cur && dir != _IO_seek_set && dir != _IO_seek_end) |
41 | { |
42 | __set_errno (EINVAL); |
43 | return EOF; |
44 | } |
45 | |
46 | /* If we have a backup buffer, get rid of it, since the __seekoff |
47 | callback may not know to do the right thing about it. |
48 | This may be over-kill, but it'll do for now. TODO */ |
49 | if (mode != 0 && ((_IO_fwide (fp, 0) < 0 && _IO_have_backup (fp)) |
50 | || (_IO_fwide (fp, 0) > 0 && _IO_have_wbackup (fp)))) |
51 | { |
52 | if (dir == _IO_seek_cur && _IO_in_backup (fp)) |
53 | { |
54 | if (_IO_vtable_offset (fp) != 0 || fp->_mode <= 0) |
55 | offset -= fp->_IO_read_end - fp->_IO_read_ptr; |
56 | else |
57 | abort (); |
58 | } |
59 | if (_IO_fwide (fp, 0) < 0) |
60 | _IO_free_backup_area (fp); |
61 | else |
62 | _IO_free_wbackup_area (fp); |
63 | } |
64 | |
65 | return _IO_SEEKOFF (fp, offset, dir, mode); |
66 | } |
67 | |
68 | |
69 | _IO_off64_t |
70 | _IO_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) |
71 | { |
72 | _IO_off64_t retval; |
73 | |
74 | _IO_acquire_lock (fp); |
75 | retval = _IO_seekoff_unlocked (fp, offset, dir, mode); |
76 | _IO_release_lock (fp); |
77 | return retval; |
78 | } |
79 | |