1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifdef VARIANT_DARWINEXTSN
34#define _DARWIN_UNLIMITED_STREAMS
35#define COUNT	0
36#elif defined(VARIANT_LEGACY)
37#define COUNT	0
38#else
39#define COUNT	1
40#endif
41
42#if defined(LIBC_SCCS) && !defined(lint)
43static char sccsid[] = "@(#)fopen.c	8.1 (Berkeley) 6/4/93";
44#endif /* LIBC_SCCS and not lint */
45#include <sys/cdefs.h>
46__FBSDID("$FreeBSD: src/lib/libc/stdio/fopen.c,v 1.14 2008/04/22 17:03:32 jhb Exp $");
47
48#include "namespace.h"
49#include <sys/types.h>
50#include <sys/stat.h>
51#include <fcntl.h>
52#include <unistd.h>
53#include <stdio.h>
54#include <errno.h>
55#include <limits.h>
56#include "un-namespace.h"
57
58#include "local.h"
59
60FILE *
61fopen(file, mode)
62	const char * __restrict file;
63	const char * __restrict mode;
64{
65	FILE *fp;
66	int f;
67	int flags, oflags;
68
69	if ((flags = __sflags(mode, &oflags)) == 0)
70		return (NULL);
71	if ((fp = __sfp(COUNT)) == NULL)
72		return (NULL);
73	if ((f = _open(file, oflags, DEFFILEMODE)) < 0) {
74		__sfprelease(fp);		/* release */
75		return (NULL);
76	}
77	/*
78	 * File descriptors are a full int, but _file is only a short.
79	 * If we get a valid file descriptor that is greater than
80	 * SHRT_MAX, then the fd will get sign-extended into an
81	 * invalid file descriptor.  Handle this case by failing the
82	 * open.
83	 */
84	if (f > SHRT_MAX) {
85		fp->_flags = 0;			/* release */
86		_close(f);
87		errno = EMFILE;
88		return (NULL);
89	}
90	fp->_file = f;
91	fp->_flags = flags;
92	fp->_cookie = fp;
93	fp->_read = __sread;
94	fp->_write = __swrite;
95	fp->_seek = __sseek;
96	fp->_close = __sclose;
97	/*
98	 * When opening in append mode, even though we use O_APPEND,
99	 * we need to seek to the end so that ftell() gets the right
100	 * answer.  If the user then alters the seek pointer, or
101	 * the file extends, this will fail, but there is not much
102	 * we can do about this.  (We could set __SAPP and check in
103	 * fseek and ftell.)
104	 */
105	if (oflags & O_APPEND)
106		(void)_sseek(fp, (fpos_t)0, SEEK_END);
107	return (fp);
108}
109