1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28/*	  All Rights Reserved	*/
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"
31
32#include "lint.h"
33#include <mtlib.h>
34#include <stdarg.h>
35#include <values.h>
36#include <thread.h>
37#include <synch.h>
38#include <errno.h>
39#include <sys/types.h>
40#include "print.h"
41#include "libc.h"
42
43/*VARARGS2*/
44int
45snprintf(char *string, size_t n, const char *format, ...)
46{
47	ssize_t count;
48	FILE siop;
49	va_list ap;
50	size_t	max = MAXINT;
51	unsigned char tmpbuf[1]; /* dummy buffer for _doprnt() if NULL string */
52
53	siop._cnt = n - 1;
54	siop._base = siop._ptr = (unsigned char *)string;
55	siop._flag = _IOREAD;   /* distinguish dummy file descriptor */
56#ifdef _LP64
57	/*
58	 * _bufend() (_realbufend()) should return NULL for v/snprintf,
59	 * so PUT() macro in _doprnt() will bounds check.  For 32-bit,
60	 * there is no _end field, and _realbufend() will return NULL
61	 * since it cannot find the dummy FILE structure in the linked
62	 * list of FILE strucutres.  See bug 4274368.
63	 */
64	siop._end = NULL;
65#endif	/* _LP64 */
66
67	if (n == 0) {
68		/*
69		 * When n==0, string may be NULL, so always use tmpbuf to
70		 * guard for this case.  No bytes should be transmitted to
71		 * the buffer when n==0, so using tmpbuf instead of string
72		 * (ie, if string is not NULL) should not matter.
73		 */
74		siop._base = siop._ptr = tmpbuf;
75		siop._cnt = 0;
76	} else if (n > max) {
77		errno = EOVERFLOW;
78		return (EOF);
79	}
80
81	va_start(ap, format);
82	count = _ndoprnt(format, ap, &siop, 0);
83	va_end(ap);
84
85	*siop._ptr = '\0';   /* plant terminating null character */
86
87	if (count == EOF)
88		return (EOF);
89
90	/* overflow check */
91	if ((size_t)count > max) {
92		errno = EOVERFLOW;
93		return (EOF);
94	} else {
95		return ((int)count);
96	}
97}
98
99#ifndef _LP64
100
101/*
102 * 32-bit shadow function of snprintf().
103 * When using the c89 compiler to build 32-bit applications, the size
104 * of intmax_t is 32-bits, otherwise the size of intmax_t is 64-bits.
105 * The shadow function uses 32-bit size of intmax_t for %j conversion.
106 * The #pragma redefine_extname in <stdio.h> selects the proper routine
107 * at compile time for the user application.
108 * NOTE: this function is only available in the 32-bit library.
109 */
110
111int
112_snprintf_c89(char *string, size_t n, const char *format, ...)
113{
114	ssize_t count;
115	va_list ap;
116
117	va_start(ap, format);
118	count = _vsnprintf_c89(string, n, format, ap);
119	va_end(ap);
120	return ((int)count);
121}
122
123#endif	/* _LP64 */
124