1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #if defined(LIBC_SCCS) && !defined(lint) 36 static char sccsid[] = "@(#)fwrite.c 8.1 (Berkeley) 6/4/93"; 37 #endif /* LIBC_SCCS and not lint */ 38 #include <sys/cdefs.h> 39 #include "namespace.h" 40 #include <errno.h> 41 #include <stdint.h> 42 #include <stdio.h> 43 #include "un-namespace.h" 44 #include "local.h" 45 #include "fvwrite.h" 46 #include "libc_private.h" 47 48 /* 49 * Write `count' objects (each size `size') from memory to the given file. 50 * Return the number of whole objects written. 51 */ 52 size_t 53 fwrite_unlocked(const void * __restrict buf, size_t size, size_t count, 54 FILE * __restrict fp) 55 { 56 size_t n; 57 struct __suio uio; 58 struct __siov iov; 59 60 /* 61 * ANSI and SUSv2 require a return value of 0 if size or count are 0. 62 */ 63 if ((count == 0) || (size == 0)) 64 return (0); 65 66 /* 67 * Check for integer overflow. As an optimization, first check that 68 * at least one of {count, size} is at least 2^16, since if both 69 * values are less than that, their product can't possibly overflow 70 * (size_t is always at least 32 bits on FreeBSD). 71 */ 72 if (((count | size) > 0xFFFF) && 73 (count > SIZE_MAX / size)) { 74 errno = EINVAL; 75 fp->_flags |= __SERR; 76 return (0); 77 } 78 79 n = count * size; 80 81 iov.iov_base = (void *)buf; 82 uio.uio_resid = iov.iov_len = n; 83 uio.uio_iov = &iov; 84 uio.uio_iovcnt = 1; 85 86 ORIENT(fp, -1); 87 /* 88 * The usual case is success (__sfvwrite returns 0); 89 * skip the divide if this happens, since divides are 90 * generally slow and since this occurs whenever size==0. 91 */ 92 if (__sfvwrite(fp, &uio) != 0) 93 count = (n - uio.uio_resid) / size; 94 return (count); 95 } 96 97 size_t 98 fwrite(const void * __restrict buf, size_t size, size_t count, 99 FILE * __restrict fp) 100 { 101 size_t n; 102 103 FLOCKFILE_CANCELSAFE(fp); 104 n = fwrite_unlocked(buf, size, count, fp); 105 FUNLOCKFILE_CANCELSAFE(); 106 return (n); 107 } 108