/* 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 "ares_setup.h"

#ifdef HAVE_LIMITS_H

#  include <limits.h>

#endif

#include "ares.h"

#include "ares_private.h"

#ifndef HAVE_WRITEV

ares_ssize_t ares_writev(ares_socket_t s, const struct iovec *iov, int iovcnt)

{

  char *buffer, *bp;

  int i;

  size_t bytes = 0;

  ares_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 = ares_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);

  ares_free(buffer);

  return (result);

}

#endif