text: 
  /* Copyright 1998 by the Massachusetts Institute of Technology.
   * Copyright (C) 2012 Marko Kreen <markokr@gmail.com>
   *
   * 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_NETDB_H
  #  include <netdb.h>
  #endif
  #ifdef HAVE_ARPA_INET_H
  #  include <arpa/inet.h>
  #endif
  #ifdef HAVE_ARPA_NAMESER_H
  #  include <arpa/nameser.h>
  #else
  #  include "nameser.h"
  #endif
  #ifdef HAVE_ARPA_NAMESER_COMPAT_H
  #  include <arpa/nameser_compat.h>
  #endif
  
  #include "ares.h"
  #include "ares_dns.h"
  #include "ares_data.h"
  #include "ares_private.h"
  
  int
  ares_parse_soa_reply(const unsigned char *abuf, int alen,
  		     struct ares_soa_reply **soa_out)
  {
    const unsigned char *aptr;
    long len;
    char *qname = NULL, *rr_name = NULL;
    struct ares_soa_reply *soa = NULL;
    int qdcount, ancount;
    int status;
  
    if (alen < HFIXEDSZ)
      return ARES_EBADRESP;
  
    /* parse message header */
    qdcount = DNS_HEADER_QDCOUNT(abuf);
    ancount = DNS_HEADER_ANCOUNT(abuf);
    if (qdcount != 1 || ancount != 1)
      return ARES_EBADRESP;
    aptr = abuf + HFIXEDSZ;
  
    /* query name */
    status = ares__expand_name_for_response(aptr, abuf, alen, &qname, &len);
    if (status != ARES_SUCCESS)
      goto failed_stat;
    aptr += len;
  
    /* skip qtype & qclass */
    if (aptr + QFIXEDSZ > abuf + alen)
      goto failed;
    aptr += QFIXEDSZ;
  
    /* rr_name */
    status = ares__expand_name_for_response(aptr, abuf, alen, &rr_name, &len);
    if (status != ARES_SUCCESS)
      goto failed_stat;
    aptr += len;
  
    /* skip rr_type, rr_class, rr_ttl, rr_rdlen */
    if (aptr + RRFIXEDSZ > abuf + alen)
      goto failed;
    aptr += RRFIXEDSZ;
  
    /* allocate result struct */
    soa = ares_malloc_data(ARES_DATATYPE_SOA_REPLY);
    if (!soa)
      {
        status = ARES_ENOMEM;
        goto failed_stat;
      }
  
    /* nsname */
    status = ares__expand_name_for_response(aptr, abuf, alen, &soa->nsname, &len);
    if (status != ARES_SUCCESS)
      goto failed_stat;
    aptr += len;
  
    /* hostmaster */
    status = ares__expand_name_for_response(aptr, abuf, alen, &soa->hostmaster, &len);
    if (status != ARES_SUCCESS)
      goto failed_stat;
    aptr += len;
  
    /* integer fields */
    if (aptr + 5 * 4 > abuf + alen)
      goto failed;
    soa->serial = DNS__32BIT(aptr + 0 * 4);
    soa->refresh = DNS__32BIT(aptr + 1 * 4);
    soa->retry = DNS__32BIT(aptr + 2 * 4);
    soa->expire = DNS__32BIT(aptr + 3 * 4);
    soa->minttl = DNS__32BIT(aptr + 4 * 4);
  
    ares_free(qname);
    ares_free(rr_name);
  
    *soa_out = soa;
  
    return ARES_SUCCESS;
  
  failed:
    status = ARES_EBADRESP;
  
  failed_stat:
    ares_free_data(soa);
    if (qname)
      ares_free(qname);
    if (rr_name)
      ares_free(rr_name);
    return status;
  }
  
  