1 /* $OpenBSD: lseek.c,v 1.7 2003/08/11 06:23:09 deraadt Exp $ */
2 /* $NetBSD: lseek.c,v 1.3 1996/06/21 20:09:03 pk Exp $ */
3
4 /*-
5 * Copyright (c) 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * The Mach Operating System project at Carnegie-Mellon University.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)lseek.c 8.1 (Berkeley) 6/11/93
36 *
37 *
38 * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
39 * All Rights Reserved.
40 *
41 * Author: Alessandro Forin
42 *
43 * Permission to use, copy, modify and distribute this software and its
44 * documentation is hereby granted, provided that both the copyright
45 * notice and this permission notice appear in all copies of the
46 * software, derivative works or modified versions, and any portions
47 * thereof, and that both notices appear in supporting documentation.
48 *
49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
51 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 *
53 * Carnegie Mellon requests users of this software to return to
54 *
55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
56 * School of Computer Science
57 * Carnegie Mellon University
58 * Pittsburgh PA 15213-3890
59 *
60 * any improvements or extensions that they make and grant Carnegie the
61 * rights to redistribute these changes.
62 */
63
64 #include "stand.h"
65
66 off_t
67 #ifndef __INTERNAL_LIBSA_CREAD
lseek(int fd,off_t offset,int where)68 lseek(int fd, off_t offset, int where)
69 #else
70 olseek(int fd, off_t offset, int where)
71 #endif
72 {
73 struct open_file *f = &files[fd];
74
75 if ((unsigned)fd >= SOPEN_MAX || f->f_flags == 0) {
76 errno = EBADF;
77 return (-1);
78 }
79
80 if (f->f_flags & F_RAW) {
81 /*
82 * On RAW devices, update internal offset.
83 */
84 switch (where) {
85 case SEEK_SET:
86 f->f_offset = offset;
87 break;
88 case SEEK_CUR:
89 f->f_offset += offset;
90 break;
91 case SEEK_END:
92 default:
93 errno = EOFFSET;
94 return (-1);
95 }
96 return (f->f_offset);
97 }
98
99 return (f->f_ops->seek)(f, offset, where);
100 }
101