mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 20:51:11 +00:00
96 lines
2.8 KiB
C
96 lines
2.8 KiB
C
/* Copyright (C) 2009-2013 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <string.h>
|
|
#include <limits.h>
|
|
#include <stdbool.h>
|
|
#include <sys/param.h>
|
|
#if __WORDSIZE == 64 && !defined PWRITEV
|
|
/* Hide the pwritev64 declaration. */
|
|
# define pwritev64 __redirect_pwritev64
|
|
#endif
|
|
#include <sys/uio.h>
|
|
#include <bits/wordsize.h>
|
|
|
|
#ifndef PWRITEV
|
|
# define PWRITEV pwritev
|
|
# define PWRITE __pwrite
|
|
# define OFF_T off_t
|
|
#endif
|
|
|
|
|
|
static void
|
|
ifree (char **ptrp)
|
|
{
|
|
free (*ptrp);
|
|
}
|
|
|
|
|
|
/* Write data pointed by the buffers described by IOVEC, which is a
|
|
vector of COUNT 'struct iovec's, to file descriptor FD at the given
|
|
position OFFSET without change the file pointer. The data is
|
|
written in the order specified. Operates just like 'write' (see
|
|
<unistd.h>) except that the data are taken from IOVEC instead of a
|
|
contiguous buffer. */
|
|
ssize_t
|
|
PWRITEV (int fd, const struct iovec *vector, int count, OFF_T offset)
|
|
{
|
|
/* Find the total number of bytes to be read. */
|
|
size_t bytes = 0;
|
|
for (int i = 0; i < count; ++i)
|
|
{
|
|
/* Check for ssize_t overflow. */
|
|
if (SSIZE_MAX - bytes < vector[i].iov_len)
|
|
{
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
bytes += vector[i].iov_len;
|
|
}
|
|
|
|
/* Allocate a temporary buffer to hold the data. We should normally
|
|
use alloca since it's faster and does not require synchronization
|
|
with other threads. But we cannot if the amount of memory
|
|
required is too large. */
|
|
char *buffer;
|
|
char *malloced_buffer __attribute__ ((__cleanup__ (ifree))) = NULL;
|
|
if (__libc_use_alloca (bytes))
|
|
buffer = (char *) __alloca (bytes);
|
|
else
|
|
{
|
|
malloced_buffer = buffer = (char *) malloc (bytes);
|
|
if (buffer == NULL)
|
|
return -1;
|
|
}
|
|
|
|
/* Copy the data from BUFFER into the memory specified by VECTOR. */
|
|
char *ptr = buffer;
|
|
for (int i = 0; i < count; ++i)
|
|
ptr = __mempcpy ((void *) ptr, (void *) vector[i].iov_base,
|
|
vector[i].iov_len);
|
|
|
|
/* Write the data. */
|
|
return PWRITE (fd, buffer, bytes, offset);
|
|
}
|
|
#if __WORDSIZE == 64 && defined pwritev64
|
|
# undef pwritev64
|
|
strong_alias (pwritev, pwritev64)
|
|
#endif
|