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 */ 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