/*
 * 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]);
}