/* 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_NETINET_IN_H

#  include <netinet/in.h>

#endif

#ifdef HAVE_ARPA_NAMESER_H

#  include <arpa/nameser.h>

#else

#  include "nameser.h"

#endif

#include "ares.h"

#include "ares_private.h" /* for the memdebug */

/* Simply decodes a length-encoded character string. The first byte of the

 * input is the length of the string to be returned and the bytes thereafter

 * are the characters of the string. The returned result will be NULL

 * terminated.

 */

int ares_expand_string(const unsigned char *encoded,

                       const unsigned char *abuf,

                       int alen,

                       unsigned char **s,

                       long *enclen)

{

  unsigned char *q;

  union {

    ares_ssize_t sig;

     size_t uns;

  } elen;

  if (encoded == abuf+alen)

    return ARES_EBADSTR;

  elen.uns = *encoded;

  if (encoded+elen.sig+1 > abuf+alen)

    return ARES_EBADSTR;

  encoded++;

  *s = ares_malloc(elen.uns+1);

  if (*s == NULL)

    return ARES_ENOMEM;

  q = *s;

  strncpy((char *)q, (char *)encoded, elen.uns);

  q[elen.uns] = '\0';

  *s = q;

  *enclen = (long)(elen.sig+1);

  return ARES_SUCCESS;

}