xref: /netbsd-src/lib/libc/stdio/vdprintf.c (revision a536ee5124e62c9a0051a252f7833dc8f50f44c9)
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 
57 int
58 vdprintf(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