148 lines
4.3 KiB
C
148 lines
4.3 KiB
C
/*
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* Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
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* Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this list of
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* conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice, this list
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* of conditions and the following disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* 3. Neither the name of the copyright holder nor the names of its contributors may be used
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* to endorse or promote products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "sys/types.h"
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#include "sys/uio.h"
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#include "unistd.h"
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#include "string.h"
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#include "stdlib.h"
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#include "fs/file.h"
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#include "user_copy.h"
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#include "stdio.h"
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#include "limits.h"
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static char *pread_buf_and_check(int fd, const struct iovec *iov, int iovcnt, ssize_t *totalbytesread, off_t *offset)
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{
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char *buf = NULL;
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size_t buflen = 0;
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int i;
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if ((iov == NULL) || (iovcnt > IOV_MAX)) {
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*totalbytesread = VFS_ERROR;
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return NULL;
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}
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for (i = 0; i < iovcnt; ++i) {
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if (SSIZE_MAX - buflen < iov[i].iov_len) {
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set_errno(EINVAL);
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return NULL;
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}
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buflen += iov[i].iov_len;
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}
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if (buflen == 0) {
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*totalbytesread = 0;
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return NULL;
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}
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#ifdef LOSCFG_KERNEL_VM
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buf = (char *)LOS_VMalloc(buflen * sizeof(char));
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#else
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buf = (char *)malloc(buflen * sizeof(char));
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#endif
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if (buf == NULL) {
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set_errno(ENOMEM);
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*totalbytesread = VFS_ERROR;
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return buf;
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}
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*totalbytesread = (offset == NULL) ? read(fd, buf, buflen)
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: pread(fd, buf, buflen, *offset);
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if ((*totalbytesread == VFS_ERROR) || (*totalbytesread == 0)) {
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#ifdef LOSCFG_KERNEL_VM
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LOS_VFree(buf);
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#else
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free(buf);
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#endif
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return NULL;
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}
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return buf;
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}
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ssize_t vfs_readv(int fd, const struct iovec *iov, int iovcnt, off_t *offset)
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{
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int i;
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int ret;
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char *buf = NULL;
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char *curbuf = NULL;
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ssize_t bytestoread;
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ssize_t totalbytesread = 0;
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ssize_t bytesleft;
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buf = pread_buf_and_check(fd, iov, iovcnt, &totalbytesread, offset);
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if (buf == NULL) {
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return totalbytesread;
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}
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curbuf = buf;
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bytesleft = totalbytesread;
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for (i = 0; i < iovcnt; ++i) {
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bytestoread = iov[i].iov_len;
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if (bytestoread == 0) {
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continue;
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}
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if (bytesleft <= bytestoread) {
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ret = LOS_CopyFromKernel(iov[i].iov_base, bytesleft, curbuf, bytesleft);
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bytesleft = ret;
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goto out;
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}
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ret = LOS_CopyFromKernel(iov[i].iov_base, bytestoread, curbuf, bytestoread);
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if (ret != 0) {
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bytesleft = bytesleft - (bytestoread - ret);
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goto out;
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}
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bytesleft -= bytestoread;
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curbuf += bytestoread;
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}
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out:
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#ifdef LOSCFG_KERNEL_VM
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LOS_VFree(buf);
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#else
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free(buf);
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#endif
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if ((i == 0) && (ret == iov[i].iov_len)) {
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/* failed in the first iovec copy, and 0 bytes copied */
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set_errno(EFAULT);
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return VFS_ERROR;
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}
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return totalbytesread - bytesleft;
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}
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ssize_t readv(int fd, const struct iovec *iov, int iovcnt)
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{
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return vfs_readv(fd, iov, iovcnt, NULL);
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}
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