11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1990, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * This code is derived from software contributed to Berkeley by 61573Srgrimes * Chris Torek. 71573Srgrimes * 81573Srgrimes * Redistribution and use in source and binary forms, with or without 91573Srgrimes * modification, are permitted provided that the following conditions 101573Srgrimes * are met: 111573Srgrimes * 1. Redistributions of source code must retain the above copyright 121573Srgrimes * notice, this list of conditions and the following disclaimer. 131573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141573Srgrimes * notice, this list of conditions and the following disclaimer in the 151573Srgrimes * documentation and/or other materials provided with the distribution. 16249808Semaste * 3. Neither the name of the University nor the names of its contributors 171573Srgrimes * may be used to endorse or promote products derived from this software 181573Srgrimes * without specific prior written permission. 191573Srgrimes * 201573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301573Srgrimes * SUCH DAMAGE. 311573Srgrimes */ 321573Srgrimes 331573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 341573Srgrimesstatic char sccsid[] = "@(#)fread.c 8.2 (Berkeley) 12/11/93"; 351573Srgrimes#endif /* LIBC_SCCS and not lint */ 3692986Sobrien#include <sys/cdefs.h> 3792986Sobrien__FBSDID("$FreeBSD$"); 381573Srgrimes 3971579Sdeischen#include "namespace.h" 40201999Scperciva#include <errno.h> 41201999Scperciva#include <stdint.h> 421573Srgrimes#include <stdio.h> 431573Srgrimes#include <string.h> 4471579Sdeischen#include "un-namespace.h" 4513545Sjulian#include "local.h" 4635129Sjb#include "libc_private.h" 471573Srgrimes 48153467Sdavidxu/* 49153467Sdavidxu * MT-safe version 50153467Sdavidxu */ 51153467Sdavidxu 521573Srgrimessize_t 53153467Sdavidxufread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp) 541573Srgrimes{ 55185516Sru size_t ret; 56153467Sdavidxu 57153467Sdavidxu FLOCKFILE(fp); 58153467Sdavidxu ret = __fread(buf, size, count, fp); 59153467Sdavidxu FUNLOCKFILE(fp); 60153467Sdavidxu return (ret); 61153467Sdavidxu} 62153467Sdavidxu 63153467Sdavidxusize_t 64153467Sdavidxu__fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp) 65153467Sdavidxu{ 6692889Sobrien size_t resid; 6792889Sobrien char *p; 6892889Sobrien int r; 691573Srgrimes size_t total; 701573Srgrimes 711573Srgrimes /* 72195637Sed * ANSI and SUSv2 require a return value of 0 if size or count are 0. 731573Srgrimes */ 74201999Scperciva if ((count == 0) || (size == 0)) 751573Srgrimes return (0); 76201999Scperciva 77201999Scperciva /* 78201999Scperciva * Check for integer overflow. As an optimization, first check that 79201999Scperciva * at least one of {count, size} is at least 2^16, since if both 80201999Scperciva * values are less than that, their product can't possible overflow 81201999Scperciva * (size_t is always at least 32 bits on FreeBSD). 82201999Scperciva */ 83201999Scperciva if (((count | size) > 0xFFFF) && 84201999Scperciva (count > SIZE_MAX / size)) { 85201999Scperciva errno = EINVAL; 86201999Scperciva fp->_flags |= __SERR; 87201999Scperciva return (0); 88201999Scperciva } 89201999Scperciva 90201999Scperciva /* 91201999Scperciva * Compute the (now required to not overflow) number of bytes to 92201999Scperciva * read and actually do the work. 93201999Scperciva */ 94201999Scperciva resid = count * size; 95101776Stjr ORIENT(fp, -1); 961573Srgrimes if (fp->_r < 0) 971573Srgrimes fp->_r = 0; 981573Srgrimes total = resid; 991573Srgrimes p = buf; 1001573Srgrimes while (resid > (r = fp->_r)) { 1011573Srgrimes (void)memcpy((void *)p, (void *)fp->_p, (size_t)r); 1021573Srgrimes fp->_p += r; 1031573Srgrimes /* fp->_r = 0 ... done in __srefill */ 1041573Srgrimes p += r; 1051573Srgrimes resid -= r; 1061573Srgrimes if (__srefill(fp)) { 1071573Srgrimes /* no more input: return partial result */ 1081573Srgrimes return ((total - resid) / size); 1091573Srgrimes } 1101573Srgrimes } 1111573Srgrimes (void)memcpy((void *)p, (void *)fp->_p, resid); 1121573Srgrimes fp->_r -= resid; 1131573Srgrimes fp->_p += resid; 1141573Srgrimes return (count); 1151573Srgrimes} 116