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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 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 "synonyms.h" 33 #include <mtlib.h> 34 #include <stdarg.h> 35 #include <values.h> 36 #include <errno.h> 37 #include <synch.h> 38 #include <thread.h> 39 #include <sys/types.h> 40 #include "print.h" 41 #include "libc.h" 42 43 /* 44 * 32-bit shadow function _vsnprintf_c89() is included here. 45 * When using the c89 compiler to build 32-bit applications, the size 46 * of intmax_t is 32-bits, otherwise the size of intmax_t is 64-bits. 47 * The shadow function uses 32-bit size of intmax_t for j conversion. 48 * The #pragma redefine_extname in <stdio.h> selects the proper routine 49 * at compile time for the user application. 50 * NOTE: the shadow function only exists in the 32-bit library. 51 */ 52 53 /*VARARGS2*/ 54 int 55 #ifdef _C89_INTMAX32 /* _C89_INTMAX32 version in 32-bit libc only */ 56 _vsnprintf_c89(char *string, size_t n, const char *format, va_list ap) 57 #else 58 vsnprintf(char *string, size_t n, const char *format, va_list ap) 59 #endif 60 { 61 ssize_t count; 62 FILE siop; 63 size_t max = MAXINT; 64 unsigned char tmpbuf[1]; /* dummy buffer for _doprnt() if NULL string */ 65 66 siop._cnt = n - 1; 67 siop._base = siop._ptr = (unsigned char *)string; 68 siop._flag = _IOREAD; /* distinguish dummy file descriptor */ 69 #ifdef _LP64 70 /* 71 * _bufend() (_realbufend()) should return NULL for v/snprintf, 72 * so PUT() macro in _doprnt() will bounds check. For 32-bit, 73 * there is no _end field, and _realbufend() will return NULL 74 * since it cannot find the dummy FILE structure in the linked 75 * list of FILE strucutres. See bug 4274368. 76 */ 77 siop._end = NULL; 78 #endif /* _LP64 */ 79 80 if (n == 0) { 81 /* 82 * When n==0, string may be NULL, so always use tmpbuf to 83 * guard for this case. No bytes should be transmitted to 84 * the buffer when n==0, so using tmpbuf instead of string 85 * (ie, if string is not NULL) should not matter. 86 */ 87 siop._base = siop._ptr = tmpbuf; 88 siop._cnt = 0; 89 } else if (n > max) { 90 errno = EOVERFLOW; 91 return (EOF); 92 } 93 94 95 #ifdef _C89_INTMAX32 96 count = _ndoprnt(format, ap, &siop, _F_INTMAX32); 97 #else 98 count = _ndoprnt(format, ap, &siop, 0); 99 #endif /* _C89_INTMAX32 */ 100 101 *siop._ptr = '\0'; /* plant terminating null character */ 102 103 /* overflow check */ 104 if ((size_t)count > max) { 105 errno = EOVERFLOW; 106 return (EOF); 107 } else { 108 return ((int)count); 109 } 110 } 111