vdprintf.c revision 1.2 
1/*	$NetBSD: vdprintf.c,v 1.2 2011/07/17 20:54:34 joerg Exp $	*/
2
3/*-
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36#if defined(LIBC_SCCS) && !defined(lint)
37__RCSID("$NetBSD: vdprintf.c,v 1.2 2011/07/17 20:54:34 joerg Exp $");
38#endif /* LIBC_SCCS and not lint */
39
40#include "namespace.h"
41#include <sys/types.h>
42
43#include <assert.h>
44#include <errno.h>
45#include <fcntl.h>
46#include <unistd.h>
47#include <stdio.h>
48#include <limits.h>
49
50#include "reentrant.h"
51#include "local.h"
52
53#ifdef __weak_alias
54__weak_alias(vdprintf,_vdprintf)
55#endif
56
57int
58vdprintf(int fd, const char * __restrict fmt, va_list ap)
59{
60	FILE f;
61	struct __sfileext fext;
62	unsigned char buf[BUFSIZ];
63	int ret, fdflags, tmp;
64
65	_DIAGASSERT(fd != -1);
66
67	/*
68	 * File descriptors are a full int, but _file is only a short.
69	 * If we get a valid file descriptor that is greater or equal to
70	 * USHRT_MAX, then the fd will get sign-extended into an
71	 * invalid file descriptor.  Handle this case by failing the
72	 * open. (We treat the short as unsigned, and special-case -1).
73	 */
74	if (fd >= USHRT_MAX) {
75		errno = EMFILE;
76		return EOF;
77	}
78
79	if ((fdflags = fcntl(fd, F_GETFL, 0)) == -1)
80		return EOF;
81
82	tmp = fdflags & O_ACCMODE;
83	if (tmp != O_RDWR && tmp != O_WRONLY) {
84		errno = EINVAL;
85		return EOF;
86	}
87
88	if (fdflags & O_NONBLOCK) {
89		struct stat st;
90		if (fstat(fd, &st) == -1)
91			return -1;
92		if (!S_ISREG(st.st_mode)) {
93			errno = EFTYPE;
94			return EOF;
95		}
96	}
97
98	_FILEEXT_SETUP(&f, &fext);
99	__sfpinit(&f);
100	f._p = buf;
101	f._w = sizeof(buf);
102	f._flags = __SWR;
103	f._file = fd;
104	f._bf._base = buf;
105	f._bf._size = sizeof(buf);
106	f._cookie = &f;
107	f._read = NULL;
108	f._write = __swrite;
109	f._seek = NULL;
110	f._close = NULL;
111
112	if ((ret = vfprintf(&f, fmt, ap)) < 0)
113		return ret;
114
115	return fflush(&f) ? EOF : ret;
116}
117