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 <thread.h> 35 #include <synch.h> 36 #include <errno.h> 37 #include <sys/types.h> 38 #include "print.h" 39 #include "libc.h" 40 41 /*VARARGS2*/ 42 int 43 snprintf(char *string, size_t n, const char *format, ...) 44 { 45 ssize_t count; 46 FILE siop; 47 va_list ap; 48 size_t max = MAXINT; 49 unsigned char tmpbuf[1]; /* dummy buffer for _doprnt() if NULL string */ 50 51 siop._cnt = n - 1; 52 siop._base = siop._ptr = (unsigned char *)string; 53 siop._flag = _IOREAD; /* distinguish dummy file descriptor */ 54 #ifdef _LP64 55 /* 56 * _bufend() (_realbufend()) should return NULL for v/snprintf, 57 * so PUT() macro in _doprnt() will bounds check. For 32-bit, 58 * there is no _end field, and _realbufend() will return NULL 59 * since it cannot find the dummy FILE structure in the linked 60 * list of FILE strucutres. See bug 4274368. 61 */ 62 siop._end = NULL; 63 #endif /* _LP64 */ 64 65 if (n == 0) { 66 /* 67 * When n==0, string may be NULL, so always use tmpbuf to 68 * guard for this case. No bytes should be transmitted to 69 * the buffer when n==0, so using tmpbuf instead of string 70 * (ie, if string is not NULL) should not matter. 71 */ 72 siop._base = siop._ptr = tmpbuf; 73 siop._cnt = 0; 74 } else if (n > max) { 75 errno = EOVERFLOW; 76 return (EOF); 77 } 78 79 va_start(ap, format); 80 count = _ndoprnt(format, ap, &siop, 0); 81 va_end(ap); 82 83 *siop._ptr = '\0'; /* plant terminating null character */ 84 85 if (count == EOF) 86 return (EOF); 87 88 /* overflow check */ 89 if ((size_t)count > max) { 90 errno = EOVERFLOW; 91 return (EOF); 92 } else { 93 return ((int)count); 94 } 95 } 96 97 #ifndef _LP64 98 99 /* 100 * 32-bit shadow function of snprintf(). 101 * When using the c89 compiler to build 32-bit applications, the size 102 * of intmax_t is 32-bits, otherwise the size of intmax_t is 64-bits. 103 * The shadow function uses 32-bit size of intmax_t for %j conversion. 104 * The #pragma redefine_extname in <stdio.h> selects the proper routine 105 * at compile time for the user application. 106 * NOTE: this function is only available in the 32-bit library. 107 */ 108 109 int 110 _snprintf_c89(char *string, size_t n, const char *format, ...) 111 { 112 ssize_t count; 113 va_list ap; 114 115 va_start(ap, format); 116 count = _vsnprintf_c89(string, n, format, ap); 117 va_end(ap); 118 return ((int)count); 119 } 120 121 #endif /* _LP64 */ 122