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/* 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