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//
// iovec.c
//
// Scatter/gather utility routines
//
// Copyright (C) 2002 Michael Ringgaard. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of the project nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
#include <os/krnl.h>
int check_iovec(struct iovec *iov, int iovlen, int modify) {
if (iov) {
if (iovlen < 0) return -EINVAL;
if (!mem_access(iov, iovlen * sizeof(struct iovec), PT_USER_READ)) return -EFAULT;
while (iovlen > 0) {
if (iov->iov_len < 0) return -EINVAL;
if (iov->iov_base) {
if (!mem_access(iov->iov_base, iov->iov_len, modify ? PT_USER_WRITE : PT_USER_READ)) return -EFAULT;
} else if (iov->iov_len != 0) {
return -EFAULT;
}
iov++;
iovlen--;
}
} else {
if (iovlen != 0) return -EFAULT;
}
return 0;
}
size_t get_iovec_size(struct iovec *iov, int iovlen) {
size_t size = 0;
while (iovlen > 0) {
size += iov->iov_len;
iov++;
iovlen--;
}
return size;
}
struct iovec *dup_iovec(struct iovec *iov, int iovlen) {
struct iovec *newiov;
newiov = (struct iovec *) kmalloc(iovlen * sizeof(struct iovec));
if (!newiov) return NULL;
memcpy(newiov, iov, iovlen * sizeof(struct iovec));
return newiov;
}
int read_iovec(struct iovec *iov, int iovlen, char *buf, size_t count) {
size_t read = 0;
size_t len;
while (count > 0 && iovlen > 0) {
if (iov->iov_len > 0) {
len = iov->iov_len;
if (count < iov->iov_len) len = count;
memcpy(buf, iov->iov_base, len);
read += len;
(char *) iov->iov_base += len;
iov->iov_len -= len;
buf += len;
count -= len;
}
iov++;
iovlen--;
}
return read;
}
int write_iovec(struct iovec *iov, int iovlen, char *buf, size_t count) {
size_t written = 0;
size_t len;
while (count > 0 && iovlen > 0) {
if (iov->iov_len > 0) {
len = iov->iov_len;
if (count < iov->iov_len) len = count;
memcpy(iov->iov_base, buf, len);
written += len;
(char *) iov->iov_base += len;
iov->iov_len -= len;
buf += len;
count -= len;
}
iov++;
iovlen--;
}
return written;
}