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 #include "lint.h"
31 #include <mtlib.h>
32 #include <stdarg.h>
33 #include <values.h>
34 #include <errno.h>
35 #include <synch.h>
36 #include <thread.h>
37 #include <sys/types.h>
38 #include "print.h"
39 #include "libc.h"
40
41 /*
42 * 32-bit shadow function _vsnprintf_c89() is included here.
43 * When using the c89 compiler to build 32-bit applications, the size
44 * of intmax_t is 32-bits, otherwise the size of intmax_t is 64-bits.
45 * The shadow function uses 32-bit size of intmax_t for j conversion.
46 * The #pragma redefine_extname in <stdio.h> selects the proper routine
47 * at compile time for the user application.
48 * NOTE: the shadow function only exists in the 32-bit library.
49 */
50
51 /*VARARGS2*/
52 int
53 #ifdef _C89_INTMAX32 /* _C89_INTMAX32 version in 32-bit libc only */
_vsnprintf_c89(char * string,size_t n,const char * format,va_list ap)54 _vsnprintf_c89(char *string, size_t n, const char *format, va_list ap)
55 #else
56 vsnprintf(char *string, size_t n, const char *format, va_list ap)
57 #endif
58 {
59 ssize_t count;
60 FILE siop;
61 size_t max = MAXINT;
62 unsigned char tmpbuf[1]; /* dummy buffer for _doprnt() if NULL string */
63
64 siop._cnt = n - 1;
65 siop._base = siop._ptr = (unsigned char *)string;
66 siop._flag = _IOREAD; /* distinguish dummy file descriptor */
67 #ifdef _LP64
68 /*
69 * _bufend() (_realbufend()) should return NULL for v/snprintf,
70 * so PUT() macro in _doprnt() will bounds check. For 32-bit,
71 * there is no _end field, and _realbufend() will return NULL
72 * since it cannot find the dummy FILE structure in the linked
73 * list of FILE strucutres. See bug 4274368.
74 */
75 siop._end = NULL;
76 #endif /* _LP64 */
77
78 if (n == 0) {
79 /*
80 * When n==0, string may be NULL, so always use tmpbuf to
81 * guard for this case. No bytes should be transmitted to
82 * the buffer when n==0, so using tmpbuf instead of string
83 * (ie, if string is not NULL) should not matter.
84 */
85 siop._base = siop._ptr = tmpbuf;
86 siop._cnt = 0;
87 } else if (n > max) {
88 errno = EOVERFLOW;
89 return (EOF);
90 }
91
92
93 #ifdef _C89_INTMAX32
94 count = _ndoprnt(format, ap, &siop, _F_INTMAX32);
95 #else
96 count = _ndoprnt(format, ap, &siop, 0);
97 #endif /* _C89_INTMAX32 */
98
99 *siop._ptr = '\0'; /* plant terminating null character */
100
101 /* overflow check */
102 if ((size_t)count > max) {
103 errno = EOVERFLOW;
104 return (EOF);
105 } else {
106 return ((int)count);
107 }
108 }
109