/*
* answer.c -- manipulating query answers and encoding them.
*
* Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
*
* See LICENSE for the license.
*
*/

#include "config.h"

#include <string.h>

#include "answer.h"
#include "packet.h"
#include "query.h"

void
answer_init(answer_type *answer)
{
       answer->rrset_count = 0;
}

int
answer_add_rrset(answer_type *answer, rr_section_type section,
                domain_type *domain, rrset_type *rrset)
{
       size_t i;

       assert(section >= ANSWER_SECTION && section < RR_SECTION_COUNT);
       assert(domain);
       assert(rrset);

       /* Don't add an RRset multiple times.  */
       for (i = 0; i < answer->rrset_count; ++i) {
               if (answer->rrsets[i] == rrset &&
                       answer->domains[i]->number == domain->number) {
                       if (section < answer->section[i]) {
                               answer->section[i] = section;
                               return 1;
                       } else {
                               return 0;
                       }
               }
       }

       if (answer->rrset_count >= MAXRRSPP) {
               /* XXX: Generate warning/error? */
               return 0;
       }

       answer->section[answer->rrset_count] = section;
       answer->domains[answer->rrset_count] = domain;
       answer->rrsets[answer->rrset_count] = rrset;
       ++answer->rrset_count;

       return 1;
}

void
encode_answer(query_type *q, const answer_type *answer)
{
       uint16_t counts[RR_SECTION_COUNT];
       rr_section_type section;
       size_t i;
       int minimal_respsize = IPV4_MINIMAL_RESPONSE_SIZE;
       int done = 0;

#if defined(INET6) && defined(MINIMAL_RESPONSES)
       if (q->client_addr.ss_family == AF_INET6)
               minimal_respsize = IPV6_MINIMAL_RESPONSE_SIZE;
#endif

       for (section = ANSWER_SECTION; section < RR_SECTION_COUNT; ++section) {
               counts[section] = 0;
       }

       for (section = ANSWER_SECTION;
            !TC(q->packet) && section < RR_SECTION_COUNT;
            ++section) {

               for (i = 0; !TC(q->packet) && i < answer->rrset_count; ++i) {
                       if (answer->section[i] == section) {
                               counts[section] += packet_encode_rrset(
                                       q,
                                       answer->domains[i],
                                       answer->rrsets[i],
                                       section, minimal_respsize, &done);
                       }
               }
#ifdef MINIMAL_RESPONSES
               /**
                * done is set prematurely, because the minimal response size
                * has been reached. No need to try adding RRsets in following
                * sections.
                */
               if (done) {
                       /* delegations should have a usable address in it */
                       if(section == ADDITIONAL_A_SECTION &&
                               counts[ADDITIONAL_A_SECTION] == 0 &&
                               q->delegation_domain)
                               TC_SET(q->packet);
                       break;
               }
#endif
       }

       ANCOUNT_SET(q->packet, counts[ANSWER_SECTION]);
       NSCOUNT_SET(q->packet,
                   counts[AUTHORITY_SECTION]
                   + counts[OPTIONAL_AUTHORITY_SECTION]);
       ARCOUNT_SET(q->packet,
                   counts[ADDITIONAL_A_SECTION]
                   + counts[ADDITIONAL_AAAA_SECTION]
                   + counts[ADDITIONAL_OTHER_SECTION]);
}