curl/ares/ares_writev.c

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/* $Id$ */
/* Copyright 1998 by the Massachusetts Institute of Technology.
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting
* documentation, and that the name of M.I.T. not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is"
* without express or implied warranty.
*/
#include "setup.h"
#ifdef HAVE_LIMITS_H
# include <limits.h>
#endif
#include "ares.h"
#include "ares_private.h"
#ifndef HAVE_WRITEV
ssize_t ares_writev(ares_socket_t s, const struct iovec *iov, int iovcnt)
{
char *buffer, *bp;
int i;
size_t bytes = 0;
ssize_t result;
/* Validate iovcnt */
if (iovcnt <= 0)
{
SET_ERRNO(EINVAL);
return (-1);
}
/* Validate and find the sum of the iov_len values in the iov array */
for (i = 0; i < iovcnt; i++)
{
if (iov[i].iov_len > INT_MAX - bytes)
{
SET_ERRNO(EINVAL);
return (-1);
}
bytes += iov[i].iov_len;
}
if (bytes == 0)
return (0);
/* Allocate a temporary buffer to hold the data */
buffer = malloc(bytes);
if (!buffer)
{
SET_ERRNO(ENOMEM);
return (-1);
}
/* Copy the data into buffer */
for (bp = buffer, i = 0; i < iovcnt; ++i)
{
memcpy (bp, iov[i].iov_base, iov[i].iov_len);
bp += iov[i].iov_len;
}
/* Send buffer contents */
result = swrite(s, buffer, bytes);
free(buffer);
return (result);
}
#endif