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/* $OpenBSD: fwrite.c,v 1.12 2015/08/31 02:53:57 guenther Exp $ */ |
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/*- |
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* Copyright (c) 1990, 1993 |
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* The Regents of the University of California. All rights reserved. |
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* |
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* This code is derived from software contributed to Berkeley by |
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* Chris Torek. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <stdint.h> |
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#include <errno.h> |
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#include "local.h" |
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#include "fvwrite.h" |
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#define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 4)) |
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/* |
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* Write `count' objects (each size `size') from memory to the given file. |
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* Return the number of whole objects written. |
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*/ |
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size_t |
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fwrite(const void *buf, size_t size, size_t count, FILE *fp) |
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{ |
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size_t n; |
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struct __suio uio; |
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struct __siov iov; |
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int ret; |
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/* |
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* Extension: Catch integer overflow |
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*/ |
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✗✓✗✗
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if ((size >= MUL_NO_OVERFLOW || count >= MUL_NO_OVERFLOW) && |
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size > 0 && SIZE_MAX / size < count) { |
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errno = EOVERFLOW; |
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fp->_flags |= __SERR; |
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return (0); |
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} |
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/* |
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* ANSI and SUSv2 require a return value of 0 if size or count are 0. |
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*/ |
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✗✓ |
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if ((n = count * size) == 0) |
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return (0); |
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iov.iov_base = (void *)buf; |
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uio.uio_resid = iov.iov_len = n; |
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uio.uio_iov = &iov; |
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uio.uio_iovcnt = 1; |
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/* |
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* The usual case is success (__sfvwrite returns 0); |
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* skip the divide if this happens, since divides are |
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* generally slow and since this occurs whenever size==0. |
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*/ |
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✗✓ |
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FLOCKFILE(fp); |
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✓✗✓✗
✓✓ |
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_SET_ORIENTATION(fp, -1); |
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ret = __sfvwrite(fp, &uio); |
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✗✓ |
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FUNLOCKFILE(fp); |
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✓✗ |
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if (ret == 0) |
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return (count); |
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return ((n - uio.uio_resid) / size); |
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} |
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DEF_STRONG(fwrite); |