// Copyright (C) 2013-2025 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>

#include <asiolink/io_address.h>
#include <dhcp_ddns/ncr_msg.h>
#include <dhcp/dhcp6.h>
#include <dhcp/option.h>
#include <dhcp/option_custom.h>
#include <dhcp/option6_client_fqdn.h>
#include <dhcp/option6_ia.h>
#include <dhcp/option6_iaaddr.h>
#include <dhcp/option6_status_code.h>
#include <dhcp/option_int_array.h>
#include <dhcp/testutils/iface_mgr_test_config.h>
#include <dhcpsrv/lease.h>
#include <dhcpsrv/lease_mgr_factory.h>
#include <dhcpsrv/ncr_generator.h>
#include <dhcp6/tests/dhcp6_client.h>
#include <dhcp6/tests/dhcp6_test_utils.h>

#include <boost/pointer_cast.hpp>
#include <gtest/gtest.h>

using namespace isc;
using namespace isc::dhcp::test;
using namespace isc::asiolink;
using namespace isc::dhcp;
using namespace isc::dhcp_ddns;
using namespace isc::util;
using namespace isc::hooks;
using namespace std;

namespace {

/// @brief A test fixture class for testing DHCPv6 Client FQDN Option handling.
class FqdnDhcpv6SrvTest : public Dhcpv6SrvTest {
public:
    // Bit Constants for turning on and off DDNS configuration options.
    // (Defined here as these are only meaningful to this class.)
    static const uint16_t OVERRIDE_NO_UPDATE = 1;
    static const uint16_t OVERRIDE_CLIENT_UPDATE = 2;
    static const uint16_t REPLACE_CLIENT_NAME = 4;

    // Enum used to specify whether a client (packet) should include
    // the hostname option
    enum ClientNameFlag {
        CLIENT_NAME_PRESENT,
        CLIENT_NAME_NOT_PRESENT
    };

    // Enum used to specify whether the server should replace/supply
    // the hostname or not
    enum ReplacementFlag {
        NAME_REPLACED,
        NAME_NOT_REPLACED
    };

    // Type used to indicate whether or not forward updates are expected
    struct ExpFwd {
        ExpFwd(bool exp_fwd) : value_(exp_fwd){};
        bool value_;
    };

    // Type used to indicate whether or not reverse updates are expected
    struct ExpRev {
        ExpRev(bool exp_rev) : value_(exp_rev){};
        bool value_;
    };

    /// @brief Constructor
    FqdnDhcpv6SrvTest()
        : Dhcpv6SrvTest(),
          d2_mgr_(CfgMgr::instance().getD2ClientMgr()),
          iface_mgr_test_config_(true) {
        // generateClientId assigns DUID to duid_.
        generateClientId();
        lease_.reset(new Lease6(Lease::TYPE_NA, IOAddress("2001:db8:1::1"),
                                duid_, 1234, 501, 502, 1, HWAddrPtr()));
        // Config DDNS to be enabled, all controls off
        enableD2();
    }

    /// @brief Destructor
    virtual ~FqdnDhcpv6SrvTest() {
        // Default constructor creates a config with DHCP-DDNS updates
        // disabled.
        D2ClientConfigPtr cfg(new D2ClientConfig());
        CfgMgr::instance().setD2ClientConfig(cfg);
    }

    /// @brief Sets the server's DDNS configuration to ddns updates disabled.
    void disableD2() {
        // Default constructor creates a config with DHCP-DDNS updates
        // disabled.
        D2ClientConfigPtr cfg(new D2ClientConfig());
        CfgMgr::instance().setD2ClientConfig(cfg);
    }

    /// @brief Enables DHCP-DDNS updates with the given options enabled.
    ///
    /// Replaces the current D2ClientConfiguration with a configuration
    /// which as updates enabled and the control options set based upon
    /// the bit mask of options.
    ///
    /// @param mask Bit mask of configuration options that should be enabled.
    void enableD2(const uint16_t mask = 0) {
        D2ClientConfigPtr cfg;

        ASSERT_NO_THROW(cfg.reset(new D2ClientConfig(true,
                                  isc::asiolink::IOAddress("::1"), 53001,
                                  isc::asiolink::IOAddress("::"), 0,
                                  1024, dhcp_ddns::NCR_UDP, dhcp_ddns::FMT_JSON)));

        ASSERT_NO_THROW(CfgMgr::instance().setD2ClientConfig(cfg));

        // Now we'll set the DDNS parameters at the subnet level.
        // These should get fetched when getDdnsParams() is invoked.
        ASSERT_TRUE(subnet_) << "enableD2 called without subnet_ set";
        subnet_->setDdnsSendUpdates(true);
        subnet_->setDdnsOverrideNoUpdate(mask & OVERRIDE_NO_UPDATE);
        subnet_->setDdnsOverrideClientUpdate(mask & OVERRIDE_CLIENT_UPDATE);
        subnet_->setDdnsReplaceClientNameMode((mask & REPLACE_CLIENT_NAME) ?
                                              D2ClientConfig::RCM_WHEN_PRESENT :
                                              D2ClientConfig::RCM_NEVER);
        subnet_->setDdnsGeneratedPrefix("myhost");
        subnet_->setDdnsQualifyingSuffix("example.com");
        // In V6 the dot (".") can, and equally can not be specified in the
        // "hostname-char-set" because the FQDN is split before any character
        // is replaced and then is put back together.
        subnet_->setHostnameCharSet("[^A-Za-z0-9.-]");
        subnet_->setHostnameCharReplacement("x");
        subnet_->setDdnsConflictResolutionMode("check-with-dhcid");

        ASSERT_NO_THROW(srv_->startD2());
    }

    // Fetch DDNS parameter set scoped to the current subnet_.
    DdnsParamsPtr getDdnsParams() {
        ConstElementPtr cfg = CfgMgr::instance().getCurrentCfg()->toElement();
        if (!subnet_) {
            ADD_FAILURE() << "getDdnsParams() - subnet_ is empty!";
            return (DdnsParamsPtr(new DdnsParams()));
        }

        return(CfgMgr::instance().getCurrentCfg()->getDdnsParams(subnet_));
    }

    /// @brief Construct the DHCPv6 Client FQDN option using flags and
    /// domain-name.
    ///
    /// @param flags Flags to be set for the created option.
    /// @param fqdn_name A name which should be stored in the option.
    /// @param fqdn_type A type of the name carried by the option: partial
    /// or fully qualified.
    ///
    /// @return A pointer to the created option.
    Option6ClientFqdnPtr
    createClientFqdn(const uint8_t flags,
                     const std::string& fqdn_name,
                     const Option6ClientFqdn::DomainNameType fqdn_type) {
        return (Option6ClientFqdnPtr(new Option6ClientFqdn(flags,
                                                           fqdn_name,
                                                           fqdn_type)));
    }

    /// @brief Create a message with or without DHCPv6 Client FQDN Option.
    ///
    /// @param msg_type A type of the DHCPv6 message to be created.
    /// @param fqdn_flags Flags to be carried in the FQDN option.
    /// @param fqdn_domain_name A name to be carried in the FQDN option.
    /// @param fqdn_type A type of the name carried by the option: partial
    /// or fully qualified.
    /// @param include_oro A boolean value which indicates whether the ORO
    /// option should be added to the message (if true).
    /// @param srvid server id to be stored in the message.
    ///
    /// @return An object representing the created message.
    Pkt6Ptr generateMessage(uint8_t msg_type,
                            const uint8_t fqdn_flags,
                            const std::string& fqdn_domain_name,
                            const Option6ClientFqdn::DomainNameType
                            fqdn_type,
                            const bool include_oro,
                            OptionPtr srvid = OptionPtr()) {
        Pkt6Ptr pkt = Pkt6Ptr(new Pkt6(msg_type, 1234));
        pkt->setIface("eth0");
        pkt->setIndex(ETH0_INDEX);
        Option6IAPtr ia = generateIA(D6O_IA_NA, 234, 1500, 3000);
        if (msg_type != DHCPV6_REPLY) {
            IOAddress hint("2001:db8:1:1::dead:beef");
            OptionPtr hint_opt(new Option6IAAddr(D6O_IAADDR, hint, 300, 500));
            ia->addOption(hint_opt);
            pkt->addOption(ia);
        }

        OptionPtr clientid = generateClientId();
        pkt->addOption(clientid);
        if (srvid && (msg_type != DHCPV6_SOLICIT)) {
            pkt->addOption(srvid);
        }

        pkt->addOption(createClientFqdn(fqdn_flags, fqdn_domain_name,
                                            fqdn_type));

        if (include_oro) {
            OptionUint16ArrayPtr oro(new OptionUint16Array(Option::V6,
                                                           D6O_ORO));
            oro->addValue(D6O_CLIENT_FQDN);
            pkt->addOption(oro);
        }

        return (pkt);
    }

    /// @brief Creates instance of the DHCPv6 message with client id and
    /// server id.
    ///
    /// @param msg_type A type of the message to be created.
    ///
    /// @return An object representing the created message.
    Pkt6Ptr generateMessageWithIds(const uint8_t msg_type) {
        Pkt6Ptr pkt = Pkt6Ptr(new Pkt6(msg_type, 1234));
        pkt->setIface("eth0");
        pkt->setIndex(ETH0_INDEX);
        // Generate client-id.
        OptionPtr opt_clientid = generateClientId();
        pkt->addOption(opt_clientid);

        if (msg_type != DHCPV6_SOLICIT) {
            // Generate server-id.
            pkt->addOption(srv_->getServerID());
        }

        return (pkt);
    }

    /// @brief Returns an instance of the option carrying FQDN.
    ///
    /// @param pkt A message holding FQDN option to be returned.
    ///
    /// @return An object representing DHCPv6 Client FQDN option.
    Option6ClientFqdnPtr getClientFqdnOption(const Pkt6Ptr& pkt) {
        return (boost::dynamic_pointer_cast<Option6ClientFqdn>
                (pkt->getOption(D6O_CLIENT_FQDN)));
    }

    /// @brief Adds IA option to the message.
    ///
    /// Added option holds an address.
    ///
    /// @param iaid IAID
    /// @param pkt A DHCPv6 message to which the IA option should be added.
    /// @param cxt allocation engine context to which IA option should be
    /// added.
    void addIA(const uint32_t iaid, const IOAddress& addr, Pkt6Ptr& pkt,
               AllocEngine::ClientContext6& ctx) {
        Option6IAPtr opt_ia = generateIA(D6O_IA_NA, iaid, 1500, 3000);
        Option6IAAddrPtr opt_iaaddr(new Option6IAAddr(D6O_IAADDR, addr,
                                                      300, 500));
        opt_ia->addOption(opt_iaaddr);
        pkt->addOption(opt_ia);
        ctx.createIAContext();
        ctx.currentIA().ia_rsp_ = opt_ia;
    }

    /// @brief Adds IA option to the message.
    ///
    /// Added option holds status code.
    ///
    /// @param iaid IAID
    /// @param status_code Status code
    /// @param pkt A DHCPv6 message to which the option should be added.
    /// @param cxt allocation engine context to which IA option should be
    /// added.
    void addIA(const uint32_t iaid, const uint16_t status_code, Pkt6Ptr& pkt,
               AllocEngine::ClientContext6& ctx) {
        Option6IAPtr opt_ia = generateIA(D6O_IA_NA, iaid, 1500, 3000);
        addStatusCode(status_code, "", opt_ia);
        pkt->addOption(opt_ia);
        ctx.createIAContext();
        ctx.currentIA().ia_rsp_ = opt_ia;
    }

    /// @brief Creates status code with the specified code and message.
    ///
    /// @param code A status code.
    /// @param msg A string representation of the message to be added to the
    /// Status Code option.
    ///
    /// @return An object representing the Status Code option.
    Option6StatusCodePtr createStatusCode(const uint16_t code,
                                     const std::string& msg) {
        Option6StatusCodePtr opt_status(new Option6StatusCode(code, msg));
        return (opt_status);
    }

    /// @brief Adds Status Code option to the IA.
    ///
    /// @param code A status code value.
    /// @param msg A string representation of the message to be added to the
    /// Status Code option.
    void addStatusCode(const uint16_t code, const std::string& msg,
                       Option6IAPtr& opt_ia) {
        opt_ia->addOption(createStatusCode(code, msg));
    }

    /// @brief Verifies if the DHCPv6 server processes DHCPv6 Client FQDN option
    /// as expected and subsequent interpretation of this processing when
    /// creating NCRs, if any should be created.
    ///
    /// This function simulates generation of the client's message holding FQDN.
    /// It then calls the server's @c Dhcpv6Srv::processClientFqdn option to
    /// generate server's response to the FQDN. This function returns the FQDN
    /// which should be appended to the server's response to the client.
    /// This function verifies that the FQDN option returned is correct
    /// Optionally, this function then proceeds to call createNameChangeRequests
    /// to verify if that method interprets the FQDN information properly.
    ///
    /// @param msg_type A type of the client's message.
    /// @param in_flags A value of flags field to be set for the FQDN carried
    /// in the client's message.
    /// @param in_domain_name A domain name to be carried in the client's FQDN
    /// option.
    /// @param in_domain_type A type of the domain name to be carried in the
    /// client's FQDM option (partial or fully qualified).
    /// @param exp_flags A value of flags expected in the FQDN sent by a server.
    /// @param exp_domain_name A domain name expected in the FQDN sent by a
    /// server.
    /// @param create_ncr_check if true, calls createNameChangeRequests method
    /// and tests the outcome.
    /// @param exp_fwd indicates whether or not a forward change is expected
    /// @param exp_fwd indicates whether or not a reverse change is expected
    void testFqdn(const uint16_t msg_type,
                  const uint8_t in_flags,
                  const std::string& in_domain_name,
                  const Option6ClientFqdn::DomainNameType in_domain_type,
                  const uint8_t exp_flags,
                  const std::string& exp_domain_name,
                  const bool create_ncr_check,
                  const ExpFwd& exp_fwd = ExpFwd(true),
                  const ExpRev& exp_rev = ExpRev(true)) {

        Pkt6Ptr question = generateMessage(msg_type,
                                           in_flags,
                                           in_domain_name,
                                           in_domain_type,
                                           true);

        ASSERT_TRUE(getClientFqdnOption(question));

        Pkt6Ptr answer = generateMessageWithIds(msg_type == DHCPV6_SOLICIT
                                                ? DHCPV6_ADVERTISE :
                                                DHCPV6_REPLY);

        AllocEngine::ClientContext6 ctx;
        // Set the selected subnet so ddns params get returned correctly.
        ctx.subnet_ = subnet_;

        // Create three IAs, each having different address.
        addIA(1234, IOAddress("2001:db8:1::1"), answer, ctx);

        ASSERT_NO_THROW(srv_->processClientFqdn(question, answer, ctx));
        Option6ClientFqdnPtr answ_fqdn = boost::dynamic_pointer_cast<
            Option6ClientFqdn>(answer->getOption(D6O_CLIENT_FQDN));
        ASSERT_TRUE(answ_fqdn);

        const bool flag_n = (exp_flags & Option6ClientFqdn::FLAG_N) != 0;
        const bool flag_s = (exp_flags & Option6ClientFqdn::FLAG_S) != 0;
        const bool flag_o = (exp_flags & Option6ClientFqdn::FLAG_O) != 0;

        EXPECT_EQ(flag_n, answ_fqdn->getFlag(Option6ClientFqdn::FLAG_N));
        EXPECT_EQ(flag_s, answ_fqdn->getFlag(Option6ClientFqdn::FLAG_S));
        EXPECT_EQ(flag_o, answ_fqdn->getFlag(Option6ClientFqdn::FLAG_O));

        EXPECT_EQ(exp_domain_name, answ_fqdn->getDomainName());
        // If server is configured to generate full FQDN for a client, and/or
        // client sent empty FQDN the expected result of the processing by
        // processClientFqdn is an empty, partial FQDN. This is an indication
        // for the code which performs lease allocation that the FQDN has to
        // be generated from the lease address.
        if (exp_domain_name.empty()) {
            EXPECT_EQ(Option6ClientFqdn::PARTIAL,
                      answ_fqdn->getDomainNameType());

        } else {
            EXPECT_EQ(Option6ClientFqdn::FULL, answ_fqdn->getDomainNameType());

        }

        if (create_ncr_check) {
            // Context flags are normally set during lease allocation. Since that
            // hasn't occurred we'll set them here to match the expected values.
            // Call createNameChangeRequests
            ctx.fwd_dns_update_ = exp_fwd.value_;
            ctx.rev_dns_update_ = exp_rev.value_;
            ASSERT_NO_THROW(srv_->createNameChangeRequests(answer, ctx));
            if (exp_fwd.value_ || exp_rev.value_) {
                // Should have created 1 NCR.
                NameChangeRequestPtr ncr;
                ASSERT_EQ(1, d2_mgr_.getQueueSize());
                ASSERT_NO_THROW(ncr = d2_mgr_.peekAt(0));
                ASSERT_TRUE(ncr);
                EXPECT_EQ(dhcp_ddns::CHG_ADD, ncr->getChangeType());
                EXPECT_EQ(exp_fwd.value_, ncr->isForwardChange());
                EXPECT_EQ(exp_rev.value_, ncr->isReverseChange());
                ASSERT_NO_THROW(d2_mgr_.runReadyIO());
            } else {
                // Should not have created any NCRs.
                EXPECT_EQ(0, d2_mgr_.getQueueSize());
            }
        }
    }

    // Test that the server processes the FQDN option (or lack thereof)
    // in a client request correctly, according to the ddns-replace-client-name
    // mode configuration parameter.
    //
    // @param mode - value to use for ddns-replace-client-name mode
    //
    // @param client_name_flag - specifies whether or not the client request
    // should contain a hostname option
    // @param exp_replacement_flag - specifies whether or not the server is
    // expected to replace (or supply) the FQDN/name in its response
    void testReplaceClientNameMode(const char* mode,
                                   enum ClientNameFlag client_name_flag,
                                   enum ReplacementFlag exp_replacement_flag) {
        // Configuration "template" with a replaceable mode parameter
        const char* config_template =
            "{ \"interfaces-config\": { \n"
            "  \"interfaces\": [ \"eth0\" ] \n"
            "}, \n"
            "\"valid-lifetime\": 4000, \n"
            "\"preferred-lifetime\": 3000, \n"
            "\"rebind-timer\": 2000, \n"
            "\"renew-timer\": 1000, \n"
            "\"ddns-replace-client-name\": \"%s\", \n"
            "\"ddns-qualifying-suffix\": \"fake-suffix.isc.org.\", \n"
            "\"subnet6\": [ { \n"
            "    \"id\": 1, \n"
            "    \"pools\": [ { \"pool\": \"2001:db8:1::/64\" } ], \n"
            "    \"subnet\": \"2001:db8:1::/48\", \n"
            "    \"interface\": \"eth0\" \n"
            " } ], \n"
            "\"dhcp-ddns\": { \n"
            "\"enable-updates\": true \n"
            "}} \n";

        // Create the configuration and configure the server
        char config_buf[1024];
        snprintf(config_buf, 1024, config_template, mode);
        configure(config_buf, *srv_);

        // Build our client packet
        Pkt6Ptr query;
        if (client_name_flag == CLIENT_NAME_PRESENT) {
            query = generateMessage(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S,
                                    "my.example.com.", Option6ClientFqdn::FULL,
                                    true);
        } else {
            query = generateMessageWithIds(DHCPV6_SOLICIT);
        }

        AllocEngine::ClientContext6 ctx;
        bool drop = !srv_->earlyGHRLookup(query, ctx);
        ASSERT_FALSE(drop);
        ctx.subnet_ = srv_->selectSubnet(query, drop);
        ASSERT_FALSE(drop);
        srv_->initContext(ctx, drop);

        ASSERT_FALSE(drop);
        Pkt6Ptr answer = generateMessageWithIds(DHCPV6_ADVERTISE);

        ASSERT_NO_THROW(srv_->processClientFqdn(query, answer, ctx));

        Option6ClientFqdnPtr answ_fqdn = boost::dynamic_pointer_cast<
            Option6ClientFqdn>(answer->getOption(D6O_CLIENT_FQDN));

        // Verify the contents (or lack thereof) of the FQDN
        if (exp_replacement_flag == NAME_REPLACED) {
            ASSERT_TRUE(answ_fqdn);
            EXPECT_TRUE(answ_fqdn->getDomainName().empty());
            EXPECT_EQ(Option6ClientFqdn::PARTIAL,
                      answ_fqdn->getDomainNameType());
        } else {
            if (client_name_flag == CLIENT_NAME_PRESENT) {
                ASSERT_TRUE(answ_fqdn);
                EXPECT_EQ("my.example.com.", answ_fqdn->getDomainName());
                EXPECT_EQ(Option6ClientFqdn::FULL,
                          answ_fqdn->getDomainNameType());
            } else {
                ASSERT_FALSE(answ_fqdn);
            }
        }
    }

    /// @brief Tests that the client's message holding an FQDN is processed
    /// and that lease is acquired.
    ///
    /// @param msg_type A type of the client's message.
    /// @param hostname A domain name in the client's FQDN.
    /// @param client_flags A bitmask of the client FQDN flags
    /// @param include_oro A boolean value which indicates whether the ORO
    /// option should be included in the client's message (if true) or not
    /// (if false). In the former case, the function will expect that server
    /// responds with the FQDN option. In the latter case, the function expects
    /// that the server doesn't respond with the FQDN.
    void testProcessMessage(const uint8_t msg_type,
                            const std::string& hostname,
                            const std::string& exp_hostname,
                            const uint8_t client_flags =
                                Option6ClientFqdn::FLAG_S,
                            const IOAddress& expected_address = IOAddress("2001:db8:1:1::dead:beef"),
                            const bool include_oro = true) {
        // Create a message of a specified type, add server id and
        // FQDN option.
        OptionPtr srvid = srv_->getServerID();
        // Set the appropriate FQDN type. It must be partial if hostname is
        // empty or if it does not end with dot '.'.
        Option6ClientFqdn::DomainNameType fqdn_type = ((hostname.empty() || hostname.back() != '.') ?
            Option6ClientFqdn::PARTIAL : Option6ClientFqdn::FULL);

        Pkt6Ptr req = generateMessage(msg_type, client_flags,
                                      hostname, fqdn_type, include_oro, srvid);

        // For different client's message types we have to invoke different
        // functions to generate response.
        Pkt6Ptr reply;
        AllocEngine::ClientContext6 ctx;
        bool drop = !srv_->earlyGHRLookup(req, ctx);
        ASSERT_FALSE(drop);
        ctx.subnet_ = srv_->selectSubnet(req, drop);
        ASSERT_FALSE(drop);
        srv_->initContext(ctx, drop);

        ASSERT_FALSE(drop);
        if (msg_type == DHCPV6_SOLICIT) {
            ASSERT_NO_THROW(reply = srv_->processSolicit(ctx));

        } else if (msg_type == DHCPV6_REQUEST) {
            ASSERT_NO_THROW(reply = srv_->processRequest(ctx));

        } else if (msg_type == DHCPV6_RENEW) {
            ASSERT_NO_THROW(reply = srv_->processRenew(ctx));

        } else if (msg_type == DHCPV6_RELEASE) {
            // For Release no lease will be acquired so we have to leave
            // function here.
            ASSERT_NO_THROW(reply = srv_->processRelease(ctx));
            return;
        } else {
            // We are not interested in testing other message types.
            return;
        }

        // For Solicit, we will get different message type obviously.
        if (msg_type == DHCPV6_SOLICIT) {
            checkResponse(reply, DHCPV6_ADVERTISE, 1234);

        } else {
            checkResponse(reply, DHCPV6_REPLY, 1234);
        }

        // Check verify that IA_NA is correct.
        Option6IAAddrPtr addr =
            checkIA_NA(reply, 234, subnet_->getT1(), subnet_->getT2());
        ASSERT_TRUE(addr);

        // Check that we have got the address we requested.
        checkIAAddr(addr, expected_address,
                    Lease::TYPE_NA);

        if (msg_type != DHCPV6_SOLICIT) {
            // Check that the lease exists.
            Lease6Ptr lease =
                checkLease(duid_, reply->getOption(D6O_IA_NA), addr);
            ASSERT_TRUE(lease);
            EXPECT_EQ(exp_hostname, lease->hostname_);
        }

        // The Client FQDN option should be always present in the server's
        // response, regardless if requested using ORO or not.
        Option6ClientFqdnPtr fqdn;
        ASSERT_TRUE(fqdn = boost::dynamic_pointer_cast<
                        Option6ClientFqdn>(reply->getOption(D6O_CLIENT_FQDN)));
        EXPECT_EQ(exp_hostname, fqdn->getDomainName());
    }

    /// @brief Verify that NameChangeRequest holds valid values.
    ///
    /// This function picks first NameChangeRequest from the internal server's
    /// queue and checks that it holds valid parameters. The NameChangeRequest
    /// is removed from the queue.
    ///
    /// @param type An expected type of the NameChangeRequest (Add or Remove).
    /// @param reverse An expected setting of the reverse update flag.
    /// @param forward An expected setting of the forward update flag.
    /// @param addr A string representation of the IPv6 address held in the
    /// NameChangeRequest.
    /// @param dhcid An expected DHCID value.  Ignored if blank.
    /// @note This value is the value that is produced by
    /// dhcp_ddns::D2Dhcid::createDigest() with the appropriate arguments. This
    /// method uses encryption tools to produce the value which cannot be
    /// easily duplicated by hand.  It is more or less necessary to generate
    /// these values programmatically and place them here. Should the
    /// underlying implementation of createDigest() change these test values
    /// will likely need to be updated as well.
    /// @param expires The cltt of the lease associated with the
    /// NameChangeRequest, and used to calculate NCR expires value.
    /// @param valid_lft the valid lifetime of the lease associated with the
    /// NameChangeRequest.
    /// @param fqdn The expected string value of the FQDN, if blank the
    /// check is skipped
    /// @param exp_cr_mode expected value of NCR::conflict_resolution_mode_
    /// @param ddns_ttl_percent expected value of ddns_ttl_percent used for
    /// the NCR
    /// @param exp_ddns_ttl expected configured value for ddns-ttl
    /// @param exp_ddns_ttl_min expected configured value for ddns-ttl-min
    /// @param exp_ddns_ttl_max expected configured value for ddns-ttl-max
    void verifyNameChangeRequest(const isc::dhcp_ddns::NameChangeType type,
                                 const bool reverse, const bool forward,
                                 const std::string& addr,
                                 const std::string& dhcid,
                                 const uint64_t expires,
                                 const uint16_t valid_lft,
                                 const std::string& fqdn = "",
                                 const ConflictResolutionMode exp_cr_mode = CHECK_WITH_DHCID,
                                 util::Optional<double> exp_ddns_ttl_percent
                                 = util::Optional<double>(),
                                 Optional<uint32_t> exp_ddns_ttl = Optional<uint32_t>(),
                                 Optional<uint32_t> exp_ddns_ttl_min = Optional<uint32_t>(),
                                 Optional<uint32_t> exp_ddns_ttl_max = Optional<uint32_t>()) {
        NameChangeRequestPtr ncr;
        ASSERT_NO_THROW(ncr = d2_mgr_.peekAt(0));
        ASSERT_TRUE(ncr);

        EXPECT_EQ(type, ncr->getChangeType());
        EXPECT_EQ(forward, ncr->isForwardChange());
        EXPECT_EQ(reverse, ncr->isReverseChange());
        EXPECT_EQ(addr, ncr->getIpAddress());
        if (!dhcid.empty()) {
            EXPECT_EQ(dhcid, ncr->getDhcid().toStr());
        }

        uint32_t ttl = calculateDdnsTtl(valid_lft, exp_ddns_ttl_percent, exp_ddns_ttl,
                                        exp_ddns_ttl_min, exp_ddns_ttl_max);
        if (expires != 0) {
            EXPECT_EQ(expires + ttl, ncr->getLeaseExpiresOn());
        }

        EXPECT_EQ(ttl, ncr->getLeaseLength());

        EXPECT_EQ(isc::dhcp_ddns::ST_NEW, ncr->getStatus());

        if (! fqdn.empty()) {
           EXPECT_EQ(fqdn, ncr->getFqdn());
        }

        EXPECT_EQ(exp_cr_mode, ncr->getConflictResolutionMode());

        // Process the message off the queue
        ASSERT_NO_THROW(d2_mgr_.runReadyIO());
    }

    /// @brief Updates inherited subnet and pool members
    ///
    /// Hack added to set subnet_ and pool_ members that are buried into lower
    /// level tests such as checkLease(), so one can use "meson setup" functionality
    /// rather than hand-building configured objects
    /// @param subnet_idx Element index of the desired subnet
    /// @param pool_idx Element index of the desired pool within the desired subnet
    /// @param type lease type of desired pool
    ///
    void setSubnetAndPool(int subnet_idx, int pool_idx, Lease::Type type) {
        ConstCfgSubnets6Ptr subnets = CfgMgr::instance().getCurrentCfg()->getCfgSubnets6();
        ASSERT_TRUE(subnets);
        const Subnet6Collection* subnet_col = subnets->getAll();
        ASSERT_EQ(subnet_idx + 1, subnet_col->size());
        auto subnet_it = subnet_col->begin();
        // std::advance is not available for this iterator.
        for (int i = 0; i < subnet_idx; ++i) {
            subnet_it = std::next(subnet_it);
        }
        subnet_ = *subnet_it;
        ASSERT_TRUE(subnet_);

        const PoolCollection& pool_col = subnet_->getPools(type);
        ASSERT_LE(pool_idx + 1, pool_col.size());
        PoolPtr pool = (subnet_->getPools(type)).at(pool_idx);
        ASSERT_TRUE(pool);
        pool_ = boost::dynamic_pointer_cast<Pool6>(pool);
        ASSERT_TRUE(pool);
    }

    /// @brief Verifies that DDNS TTL parameters are used when specified.
    ///
    /// @param valid_flt lease life time
    /// @param ddns_ttl_percent expected configured value for ddns-ttl-percent
    /// @param ddns_ttl expected configured value for ddns-ttl
    /// @param ddns_ttl_min expected configured value for ddns-ttl-min
    /// @param ddns_ttl_max expected configured value for ddns-ttl-max
    void testDdnsTtlParameters(uint32_t valid_lft,
                               Optional<double> ddns_ttl_percent = Optional<double>(),
                               Optional<uint32_t> ddns_ttl = Optional<uint32_t>(),
                               Optional<uint32_t> ddns_ttl_min = Optional<uint32_t>(),
                               Optional<uint32_t> ddns_ttl_max = Optional<uint32_t>()) {

        // Create Reply message with Client Id and Server id.
        Pkt6Ptr answer = generateMessageWithIds(DHCPV6_REPLY);

        // Create NameChangeRequest for the first allocated address.
        AllocEngine::ClientContext6 ctx;
        subnet_->setDdnsConflictResolutionMode("no-check-with-dhcid");
        subnet_->setDdnsTtlPercent(ddns_ttl_percent);
        subnet_->setDdnsTtl(ddns_ttl);
        subnet_->setDdnsTtlMin(ddns_ttl_min);
        subnet_->setDdnsTtlMax(ddns_ttl_max);

        ctx.subnet_ = subnet_;
        ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;

        // Create an IA.
        Option6IAPtr opt_ia = generateIA(D6O_IA_NA, 1234, 1500, 3000);
        Option6IAAddrPtr opt_iaaddr(new Option6IAAddr(D6O_IAADDR,
                                                      IOAddress("2001:db8:1::1"),
                                                      valid_lft, valid_lft));
        opt_ia->addOption(opt_iaaddr);
        answer->addOption(opt_ia);
        ctx.createIAContext();
        ctx.currentIA().ia_rsp_ = opt_ia;

        // Use domain name in upper case. It should be converted to lower-case
        // before DHCID is calculated. So, we should get the same result as if
        // we typed domain name in lower-case.
        Option6ClientFqdnPtr fqdn = createClientFqdn(Option6ClientFqdn::FLAG_S,
                                                     "MYHOST.EXAMPLE.COM",
                                                     Option6ClientFqdn::FULL);
        answer->addOption(fqdn);

        ASSERT_NO_THROW(srv_->createNameChangeRequests(answer, ctx));
        ASSERT_EQ(1, d2_mgr_.getQueueSize());

        // Verify that NameChangeRequest is correct.
        verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                                "2001:db8:1::1",
                                "000201415AA33D1187D148275136FA30300478"
                                "FAAAA3EBD29826B5C907B2C9268A6F52",
                                0, valid_lft, "", NO_CHECK_WITH_DHCID,
                                ddns_ttl_percent,
                                ddns_ttl,
                                ddns_ttl_min,
                                ddns_ttl_max);
    }

    // Reference to D2ClientMgr singleton
    D2ClientMgr& d2_mgr_;

    /// @brief Interface Manager's fake configuration control.
    IfaceMgrTestConfig iface_mgr_test_config_;

    // Holds a lease used by a test.
    Lease6Ptr lease_;
};

// A set of tests verifying server's behavior when it receives the DHCPv6
// Client Fqdn Option.

// Test server's response when client requests that server performs AAAA update.
TEST_F(FqdnDhcpv6SrvTest, serverAAAAUpdate) {
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S,
             "myhost.example.com",
             Option6ClientFqdn::FULL, Option6ClientFqdn::FLAG_S,
             "myhost.example.com.", true, ExpFwd(true), ExpRev(true));
}

// Test server's response when client provides partial domain-name and requests
// that server performs AAAA update.
TEST_F(FqdnDhcpv6SrvTest, serverAAAAUpdatePartialName) {
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S, "myhost",
             Option6ClientFqdn::PARTIAL, Option6ClientFqdn::FLAG_S,
             "myhost.example.com.", true, ExpFwd(true), ExpRev(true));
}

// Test server's response when client provides empty domain-name and requests
// that server performs AAAA update.
TEST_F(FqdnDhcpv6SrvTest, serverAAAAUpdateNoName) {
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S, "",
             Option6ClientFqdn::PARTIAL, Option6ClientFqdn::FLAG_S, "", false);
}

// Test server's response when client requests no DNS update.
TEST_F(FqdnDhcpv6SrvTest, noUpdate) {
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_N,
             "myhost.example.com",
             Option6ClientFqdn::FULL, Option6ClientFqdn::FLAG_N,
             "myhost.example.com.", true, ExpFwd(false), ExpRev(false));
}

// Test server's response when client requests no DNS update and
// ddns-override-no-updates is true.
TEST_F(FqdnDhcpv6SrvTest, overrideNoUpdate) {
    enableD2(OVERRIDE_NO_UPDATE);
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_N,
             "myhost.example.com",
             Option6ClientFqdn::FULL,
             (Option6ClientFqdn::FLAG_S | Option6ClientFqdn::FLAG_O),
             "myhost.example.com.", true, ExpFwd(true), ExpRev(true));
}

// Test server's response when client requests that server delegates the AAAA
// update to the client
TEST_F(FqdnDhcpv6SrvTest, clientAAAAUpdate) {
    testFqdn(DHCPV6_SOLICIT, 0, "myhost.example.com.",
             Option6ClientFqdn::FULL,
             0,
             "myhost.example.com.", true, ExpFwd(false), ExpRev(true));
}

// Test server's response when client requests that server delegates the AAAA
// update to the client and this delegation is not allowed.
TEST_F(FqdnDhcpv6SrvTest, clientAAAAUpdateNotAllowed) {
    enableD2(OVERRIDE_CLIENT_UPDATE);
    testFqdn(DHCPV6_SOLICIT, 0, "myhost.example.com.",
             Option6ClientFqdn::FULL,
             Option6ClientFqdn::FLAG_S | Option6ClientFqdn::FLAG_O,
             "myhost.example.com.", true, ExpFwd(true), ExpRev(true));
}

// Test that exception is thrown if supplied NULL answer packet when
// creating NameChangeRequests.
TEST_F(FqdnDhcpv6SrvTest, createNameChangeRequestsNoAnswer) {
    Pkt6Ptr answer;

    AllocEngine::ClientContext6 ctx;
    ctx.subnet_ = subnet_;
    ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;
    EXPECT_THROW(srv_->createNameChangeRequests(answer, ctx),
                 isc::Unexpected);
}

// Test that exception is thrown if supplied answer from the server
// contains no DUID when creating NameChangeRequests.
TEST_F(FqdnDhcpv6SrvTest, createNameChangeRequestsNoDUID) {
    Pkt6Ptr answer = Pkt6Ptr(new Pkt6(DHCPV6_REPLY, 1234));
    Option6ClientFqdnPtr fqdn = createClientFqdn(Option6ClientFqdn::FLAG_S,
                                                 "myhost.example.com",
                                                 Option6ClientFqdn::FULL);
    answer->addOption(fqdn);

    AllocEngine::ClientContext6 ctx;
    ctx.subnet_ = subnet_;
    ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;
    EXPECT_THROW(srv_->createNameChangeRequests(answer, ctx), isc::Unexpected);
}

// Test no NameChangeRequests if Client FQDN is not added to the server's
// response.
TEST_F(FqdnDhcpv6SrvTest, createNameChangeRequestsNoFQDN) {
    // Create Reply message with Client Id and Server id.
    Pkt6Ptr answer = generateMessageWithIds(DHCPV6_REPLY);

    AllocEngine::ClientContext6 ctx;
    ctx.subnet_ = subnet_;
    ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;
    ASSERT_NO_THROW(srv_->createNameChangeRequests(answer, ctx));

    // There should be no new NameChangeRequests.
    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that NameChangeRequests are not generated if an answer message
// contains no addresses.
TEST_F(FqdnDhcpv6SrvTest, createNameChangeRequestsNoAddr) {
    // Create Reply message with Client Id and Server id.
    Pkt6Ptr answer = generateMessageWithIds(DHCPV6_REPLY);

    // Add Client FQDN option.
    Option6ClientFqdnPtr fqdn = createClientFqdn(Option6ClientFqdn::FLAG_S,
                                                 "myhost.example.com",
                                                 Option6ClientFqdn::FULL);
    answer->addOption(fqdn);
    AllocEngine::ClientContext6 ctx;
    ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;
    ASSERT_NO_THROW(srv_->createNameChangeRequests(answer, ctx));

    // We didn't add any IAs, so there should be no NameChangeRequests in the
    // queue.
    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that exactly one NameChangeRequest is created as a result of processing
// the answer message which holds 3 IAs and when FQDN is specified.
TEST_F(FqdnDhcpv6SrvTest, createNameChangeRequests) {
    // Create Reply message with Client Id and Server id.
    Pkt6Ptr answer = generateMessageWithIds(DHCPV6_REPLY);

    // Create NameChangeRequest for the first allocated address.
    AllocEngine::ClientContext6 ctx;
    ctx.subnet_ = subnet_;
    ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;

    // Create three IAs, each having different address.
    addIA(1234, IOAddress("2001:db8:1::1"), answer, ctx);
    addIA(2345, IOAddress("2001:db8:1::2"), answer, ctx);
    addIA(3456, IOAddress("2001:db8:1::3"), answer, ctx);

    // Use domain name in upper case. It should be converted to lower-case
    // before DHCID is calculated. So, we should get the same result as if
    // we typed domain name in lower-case.
    Option6ClientFqdnPtr fqdn = createClientFqdn(Option6ClientFqdn::FLAG_S,
                                                 "MYHOST.EXAMPLE.COM",
                                                 Option6ClientFqdn::FULL);
    answer->addOption(fqdn);


    ASSERT_NO_THROW(srv_->createNameChangeRequests(answer, ctx));
    ASSERT_EQ(1, d2_mgr_.getQueueSize());

    // Verify that NameChangeRequest is correct.
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1::1",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 500);
}

// Verify that conflict resolution is turned off when the
// subnet has it disabled.
TEST_F(FqdnDhcpv6SrvTest, noConflictResolution) {
    // Create Reply message with Client Id and Server id.
    Pkt6Ptr answer = generateMessageWithIds(DHCPV6_REPLY);

    // Create NameChangeRequest for the first allocated address.
    AllocEngine::ClientContext6 ctx;
    subnet_->setDdnsConflictResolutionMode("no-check-with-dhcid");
    ctx.subnet_ = subnet_;
    ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;

    // Create three IAs, each having different address.
    addIA(1234, IOAddress("2001:db8:1::1"), answer, ctx);

    // Use domain name in upper case. It should be converted to lower-case
    // before DHCID is calculated. So, we should get the same result as if
    // we typed domain name in lower-case.
    Option6ClientFqdnPtr fqdn = createClientFqdn(Option6ClientFqdn::FLAG_S,
                                                 "MYHOST.EXAMPLE.COM",
                                                 Option6ClientFqdn::FULL);
    answer->addOption(fqdn);

    ASSERT_NO_THROW(srv_->createNameChangeRequests(answer, ctx));
    ASSERT_EQ(1, d2_mgr_.getQueueSize());

    // Verify that NameChangeRequest is correct.
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1::1",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 500, "", NO_CHECK_WITH_DHCID);
}

// Checks that NameChangeRequests to add entries are not
// created when ddns updates are disabled.
TEST_F(FqdnDhcpv6SrvTest, noAddRequestsWhenDisabled) {
    // Disable DDNS updates.
    disableD2();

    // Create Reply message with Client Id and Server id.
    Pkt6Ptr answer = generateMessageWithIds(DHCPV6_REPLY);

    // An attempt to send a NCR would throw.
    AllocEngine::ClientContext6 ctx;
    ctx.subnet_ = subnet_;
    ctx.fwd_dns_update_ = ctx.rev_dns_update_ = true;

    // Create three IAs, each having different address.
    addIA(1234, IOAddress("2001:db8:1::1"), answer, ctx);

    // Use domain name in upper case. It should be converted to lower-case
    // before DHCID is calculated. So, we should get the same result as if
    // we typed domain name in lower-case.
    Option6ClientFqdnPtr fqdn = createClientFqdn(Option6ClientFqdn::FLAG_S,
                                                 "MYHOST.EXAMPLE.COM",
                                                 Option6ClientFqdn::FULL);
    answer->addOption(fqdn);

    ASSERT_NO_THROW(srv_->createNameChangeRequests(answer, ctx));
}

// Test creation of the NameChangeRequest to remove both forward and reverse
// mapping for the given lease.
TEST_F(FqdnDhcpv6SrvTest, createRemovalNameChangeRequestFwdRev) {
    lease_->fqdn_fwd_ = true;
    lease_->fqdn_rev_ = true;
    // Part of the domain name is in upper case, to test that it gets converted
    // to lower case before DHCID is computed. So, we should get the same DHCID
    // as if we typed domain-name in lower case.
    lease_->hostname_ = "MYHOST.example.com.";

    ASSERT_NO_THROW(queueNCR(CHG_REMOVE, lease_));

    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, true,
                            "2001:db8:1::1",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            lease_->cltt_, lease_->valid_lft_);
}

// Checks that calling queueNCR would not result in error if DDNS updates are
// disabled.
TEST_F(FqdnDhcpv6SrvTest, noRemovalsWhenDisabled) {
    // Disable DDNS updates.
    disableD2();

    lease_->fqdn_fwd_ = true;
    lease_->fqdn_rev_ = true;
    // Part of the domain name is in upper case, to test that it gets converted
    // to lower case before DHCID is computed. So, we should get the same DHCID
    // as if we typed domain-name in lower case.
    lease_->hostname_ = "MYHOST.example.com.";

    // When DDNS is disabled an attempt to send a request should not throw, but
    // nothing is generated. Unfortunately, we can't see if anything get
    // generated because getting anything from the queue when DDNS is disabled
    // would result in exception.
    ASSERT_NO_THROW(queueNCR(CHG_REMOVE, lease_));
}

// Test creation of the NameChangeRequest to remove reverse mapping for the
// given lease.
TEST_F(FqdnDhcpv6SrvTest, createRemovalNameChangeRequestRev) {
    lease_->fqdn_fwd_ = false;
    lease_->fqdn_rev_ = true;
    lease_->hostname_ = "myhost.example.com.";

    ASSERT_NO_THROW(queueNCR(CHG_REMOVE, lease_));

    ASSERT_EQ(1, d2_mgr_.getQueueSize());

    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, false,
                            "2001:db8:1::1",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            lease_->cltt_, lease_->valid_lft_);
}

// Test that NameChangeRequest to remove DNS records is not generated when
// neither forward nor reverse DNS update has been performed for a lease.
TEST_F(FqdnDhcpv6SrvTest, createRemovalNameChangeRequestNoUpdate) {
    lease_->fqdn_fwd_ = false;
    lease_->fqdn_rev_ = false;

    ASSERT_NO_THROW(queueNCR(CHG_REMOVE, lease_));

    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that NameChangeRequest is not generated if the hostname hasn't been
// specified for a lease for which forward and reverse mapping has been set.
TEST_F(FqdnDhcpv6SrvTest, createRemovalNameChangeRequestNoHostname) {
    lease_->fqdn_fwd_ = true;
    lease_->fqdn_rev_ = true;
    lease_->hostname_ = "";

    Pkt6Ptr pkt(new Pkt6(DHCPREQUEST, 1234));
    ASSERT_NO_THROW(queueNCR(CHG_REMOVE, lease_));

    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that NameChangeRequest is not generated if the invalid hostname has
// been specified for a lease for which forward and reverse mapping has been
// set.
TEST_F(FqdnDhcpv6SrvTest, createRemovalNameChangeRequestWrongHostname) {
    lease_->fqdn_fwd_ = true;
    lease_->fqdn_rev_ = true;
    lease_->hostname_ = "myhost..example.com.";

    ASSERT_NO_THROW(queueNCR(CHG_REMOVE, lease_));

    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that Advertise message generated in a response to the Solicit will
// not result in generation if the NameChangeRequests.
TEST_F(FqdnDhcpv6SrvTest, processSolicit) {
    // Create a Solicit message with FQDN option and generate server's
    // response using processSolicit function.
    testProcessMessage(DHCPV6_SOLICIT, "myhost.example.com",
                       "myhost.example.com.");
    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that client may send two requests, each carrying FQDN option with
// a different domain-name. Server should use existing lease for the second
// request but modify the DNS entries for the lease according to the contents
// of the FQDN sent in the second request.
TEST_F(FqdnDhcpv6SrvTest, processTwoRequestsDiffFqdn) {
    // Create a Request message with FQDN option and generate server's
    // response using processRequest function. This will result in the
    // creation of a new lease and the appropriate NameChangeRequest
    // to add both reverse and forward mapping to DNS.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");

    // The lease should have been recorded in the database.
    lease_ = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                   IOAddress("2001:db8:1:1::dead:beef"));
    ASSERT_TRUE(lease_);

    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);

    // Client may send another request message with a new domain-name. In this
    // case the same lease will be returned. The existing DNS entry needs to
    // be replaced with a new one. Server should determine that the different
    // FQDN has been already added to the DNS. As a result, the old DNS
    // entries should be removed and the entries for the new domain-name
    // should be added. Therefore, we expect two NameChangeRequests. One to
    // remove the existing entries, one to add new entries.
    testProcessMessage(DHCPV6_REQUEST, "otherhost.example.com",
                       "otherhost.example.com.");
    ASSERT_EQ(2, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            lease_->cltt_, lease_->valid_lft_);
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201D422AA463306223D269B6CB7AFE7AAD265FC"
                            "EA97F93623019B2E0D14E5323D5A",
                            0, lease_->valid_lft_);
}

// Test that client may send two requests, each carrying FQDN option with
// the same domain-name. Server should use existing lease for the second
// request and not modify the DNS entries.
TEST_F(FqdnDhcpv6SrvTest, processTwoRequestsSameFqdn) {
    // Create a Request message with FQDN option and generate server's
    // response using processRequest function. This will result in the
    // creation of a new lease and the appropriate NameChangeRequest
    // to add both reverse and forward mapping to DNS.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");

    // The lease should have been recorded in the database.
    lease_ = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                   IOAddress("2001:db8:1:1::dead:beef"));
    ASSERT_TRUE(lease_);

    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);

    // Client may send another request message with a same domain-name. In this
    // case the same lease will be returned. The existing DNS entry should be
    // left alone, so we expect no NameChangeRequests queued..
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");
    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that NameChangeRequest is not generated when Solicit message is sent.
// The Solicit is here sent after a lease has been allocated for a client.
// The Solicit conveys a different hostname which would trigger updates to
// DNS if the Request was sent instead of Soicit. The code should differentiate
// behavior depending whether Solicit or Request is sent.
TEST_F(FqdnDhcpv6SrvTest, processRequestSolicit) {
    // Create a Request message with FQDN option and generate server's
    // response using processRequest function. This will result in the
    // creation of a new lease and the appropriate NameChangeRequest
    // to add both reverse and forward mapping to DNS.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);

    // When the returning client sends Solicit the code should never generate
    // NameChangeRequest and preserve existing DNS entries for the client.
    // The NameChangeRequest should only be generated when a client sends
    // Request or Renew.
    testProcessMessage(DHCPV6_SOLICIT, "otherhost.example.com",
                       "otherhost.example.com.");
    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Test that client may send Request followed by the Renew, both holding
// FQDN options, but each option holding different domain-name. The Renew
// should result in generation of the two NameChangeRequests, one to remove
// DNS entry added previously when Request was processed, another one to
// add a new entry for the FQDN held in the Renew.
/// @todo: Fix will be available on trac3677
TEST_F(FqdnDhcpv6SrvTest, processRequestRenewDiffFqdn) {
    // Create a Request message with FQDN option and generate server's
    // response using processRequest function. This will result in the
    // creation of a new lease and the appropriate NameChangeRequest
    // to add both reverse and forward mapping to DNS.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");
    // The lease should have been recorded in the database.
    lease_ = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                   IOAddress("2001:db8:1:1::dead:beef"));
    ASSERT_TRUE(lease_);

    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);

    // Client may send Renew message with a new domain-name. In this
    // case the same lease will be returned. The existing DNS entry needs to
    // be replaced with a new one. Server should determine that the different
    // FQDN has been already added to the DNS. As a result, the old DNS
    // entries should be removed and the entries for the new domain-name
    // should be added. Therefore, we expect two NameChangeRequests. One to
    // remove the existing entries, one to add new entries.
    testProcessMessage(DHCPV6_RENEW, "otherhost.example.com",
                       "otherhost.example.com.");
    ASSERT_EQ(2, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            lease_->cltt_, lease_->valid_lft_);
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201D422AA463306223D269B6CB7AFE7AAD265FC"
                            "EA97F93623019B2E0D14E5323D5A",
                            0, lease_->valid_lft_);
}

// Test that client may send Request followed by the Renew, both holding
// FQDN options, but each option holding different domain-name. The Renew
// should result in generation of the two NameChangeRequests, one to remove
// DNS entry added previously when Request was processed, another one to
// add a new entry for the FQDN held in the Renew.
TEST_F(FqdnDhcpv6SrvTest, processRequestRenewSameFqdn) {
    // Create a Request message with FQDN option and generate server's
    // response using processRequest function. This will result in the
    // creation of a new lease and the appropriate NameChangeRequest
    // to add both reverse and forward mapping to DNS.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);

    ASSERT_EQ(0, d2_mgr_.getQueueSize());

    // Client may send Renew message with a same domain-name. In this
    // case the same lease will be returned. No DNS updates should be
    // required, so the NCR queue should be empty.
    testProcessMessage(DHCPV6_RENEW, "myhost.example.com",
                       "myhost.example.com.");
    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Tests that renewals using the same domain name but differing values for
// the directional update flags result in NCRs or not, accordingly.
// If the new leases's flags are the same as the previous lease's flags,
// then no requests should be generated.  If at lease one of the new lease's
// flags differ from the previous lease, then:
// A: A removal NCR should be created based on the previous leases's flags
// if at least one of those flags are true
// B: An add NCR should be created based on the new lease's flags, if at
// least one of those flags are true
TEST_F(FqdnDhcpv6SrvTest, processRequestRenewFqdnFlags) {
    // Create a Request message with FQDN option but with N flag = 1, which
    // means no updates should be done. This should result in no NCRs.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.", Option6ClientFqdn::FLAG_N);
    // Queue should be empty.
    ASSERT_EQ(0, d2_mgr_.getQueueSize());

    // Now renew with Both N and S = 0.  This means the server should only
    // do reverse updates and should result in a reverse-only NCR.
    testProcessMessage(DHCPV6_RENEW, "myhost.example.com",
                       "myhost.example.com.", 0);
    // We should a only have reverse-only ADD, no remove.
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, false,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);

    // Renew again with the same flags, this should not generate any NCRs.
    testProcessMessage(DHCPV6_RENEW, "myhost.example.com",
                       "myhost.example.com.", 0);
    // Queue should be empty.
    ASSERT_EQ(0, d2_mgr_.getQueueSize());

    // Renew with both N and S flags = 0. This tells the server to update
    // both directions, which should change forward flag to true. This should
    // generate a reverse only remove and a dual add.
    testProcessMessage(DHCPV6_RENEW, "myhost.example.com",
                       "myhost.example.com.", Option6ClientFqdn::FLAG_S);

    // We need the lease for the expiration value.
    lease_ = LeaseMgrFactory::
             instance().getLease6(Lease::TYPE_NA,
                                  IOAddress("2001:db8:1:1::dead:beef"));
    ASSERT_TRUE(lease_);

    // We should have two NCRs, one remove and one add.
    ASSERT_EQ(2, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, false,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            lease_->cltt_, lease_->valid_lft_);

    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, lease_->valid_lft_);

    // Lastly, we renew with the N flag = 1 (which means no updates) so we
    // should have a dual direction remove NCR but NO add NCR.
    testProcessMessage(DHCPV6_RENEW, "myhost.example.com",
                       "myhost.example.com.", Option6ClientFqdn::FLAG_N);
    // We should only have the removal NCR.
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            lease_->cltt_, lease_->valid_lft_);
}

TEST_F(FqdnDhcpv6SrvTest, processRequestRelease) {
    CfgMgr::instance().getCurrentCfg()->getCfgExpiration()->setFlushReclaimedTimerWaitTime(0);
    CfgMgr::instance().getCurrentCfg()->getCfgExpiration()->setHoldReclaimedTime(0);

    // Create a Request message with FQDN option and generate server's
    // response using processRequest function. This will result in the
    // creation of a new lease and the appropriate NameChangeRequest
    // to add both reverse and forward mapping to DNS.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");

    // The lease should have been recorded in the database.
    lease_ = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                   IOAddress("2001:db8:1:1::dead:beef"));
    ASSERT_TRUE(lease_);

    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, lease_->valid_lft_);

    // Client may send Release message. In this case the lease should be
    // removed and all existing DNS entries for this lease should also
    // be removed. Therefore, we expect that single NameChangeRequest to
    // remove DNS entries is generated.
    testProcessMessage(DHCPV6_RELEASE, "otherhost.example.com",
                       "otherhost.example.com.");
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            lease_->cltt_, lease_->valid_lft_);
}

TEST_F(FqdnDhcpv6SrvTest, processRequestReleaseNoDelete) {
    // Create a Request message with FQDN option and generate server's
    // response using processRequest function. This will result in the
    // creation of a new lease and the appropriate NameChangeRequest
    // to add both reverse and forward mapping to DNS.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");

    // The lease should have been recorded in the database.
    lease_ = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                   IOAddress("2001:db8:1:1::dead:beef"));
    ASSERT_TRUE(lease_);

    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, lease_->valid_lft_);

    // Client may send Release message. In this case the lease should be
    // expired and no NameChangeRequest to remove DNS entries is generated.
    testProcessMessage(DHCPV6_RELEASE, "otherhost.example.com",
                       "otherhost.example.com.");
    ASSERT_EQ(0, d2_mgr_.getQueueSize());
}

// Checks that the server include DHCPv6 Client FQDN option in its
// response even when client doesn't request this option using ORO.
TEST_F(FqdnDhcpv6SrvTest, processRequestWithoutFqdn) {
    // The last parameter disables use of the ORO to request FQDN option
    // In this case, we expect that the FQDN option will not be included
    // in the server's response. The testProcessMessage will check that.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.", Option6ClientFqdn::FLAG_S,
                       IOAddress("2001:db8:1:1::dead:beef"), false);
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);
}

// Checks that FQDN is generated from an ip address, when client sends an empty
// FQDN.
TEST_F(FqdnDhcpv6SrvTest, processRequestEmptyFqdn) {
    testProcessMessage(DHCPV6_REQUEST, "",
                       "myhost-2001-db8-1-1--dead-beef.example.com.",
                       Option6ClientFqdn::FLAG_S,
                       IOAddress("2001:db8:1:1::dead:beef"), false);
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201C905E54BE12DE6AF92ADE72752B9F362"
                            "13B5A8BC9D217548CD739B4CF31AFB1B",
                            0, 4000);
}

// Checks that when the server reuses expired lease, the NameChangeRequest
// is generated to remove the DNS mapping for the expired lease and second
// NameChangeRequest to add a DNS mapping for a new lease.
TEST_F(FqdnDhcpv6SrvTest, processRequestReuseExpiredLease) {
    // This address will be used throughout the test.
    IOAddress addr("2001:db8:1:1::dead:beef");
    // We are going to configure a subnet with a pool that consists of
    // exactly one address. This address will be handed out to the
    // client, will get expired and then be reused.
    CfgMgr::instance().clear();
    subnet_ = Subnet6::create(IOAddress("2001:db8:1:1::"),
                              56, 1, 2, 3, 4, SubnetID(10));
    subnet_->setIface("eth0");
    subnet_->setDdnsSendUpdates(true);

    pool_ = Pool6Ptr(new Pool6(Lease::TYPE_NA, addr, addr));
    subnet_->addPool(pool_);
    CfgMgr::instance().getStagingCfg()->getCfgSubnets6()->add(subnet_);
    CfgMgr::instance().commit();

    // Enable D2.
    enableD2();

    // Allocate a lease.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.");
    // Test that the appropriate NameChangeRequest has been generated.
    ASSERT_EQ(1, d2_mgr_.getQueueSize());

    // Get the lease acquired.
    Lease6Ptr lease =
        LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA, addr);
    ASSERT_TRUE(lease);

    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, lease_->valid_lft_);
    // One of the following: IAID, DUID or subnet identifier has to be changed
    // because otherwise the allocation engine will treat the lease as
    // being renewed by the same client. If we at least change subnet identifier
    // the lease will be treated as expired lease to be reused.
    ++lease->subnet_id_;

    // Move the cllt back in time and make sure that the lease got expired.
    lease->cltt_ = time(NULL) - 10;
    lease->valid_lft_ = 5;
    ASSERT_TRUE(lease->expired());
    // Change the hostname so as the name change request for removing existing
    // DNS mapping is generated.
    lease->hostname_ = "otherhost.example.com.";
    // Update the lease in the lease database.
    LeaseMgrFactory::instance().updateLease6(lease);

    // Simulate another lease acquisition. Since, our pool consists of
    // exactly one address and this address is used by the lease in the
    // lease database, it is guaranteed that the allocation engine will
    // reuse this lease.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com.",
                       "myhost.example.com.");
    ASSERT_EQ(2, d2_mgr_.getQueueSize());
    // The first name change request generated, should remove a DNS
    // mapping for an expired lease.
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201D422AA463306223D269B6CB7AFE7AAD2"
                            "65FCEA97F93623019B2E0D14E5323D5A",
                            lease->cltt_, lease->valid_lft_);
    // The second name change request should add a DNS mapping for
    // a new lease.
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52", 0, 4);
}

TEST_F(FqdnDhcpv6SrvTest, processClientDelegation) {
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "myhost.example.com.", 0);
    ASSERT_EQ(1, d2_mgr_.getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, false,
                            "2001:db8:1:1::dead:beef",
                            "000201415AA33D1187D148275136FA30300478"
                            "FAAAA3EBD29826B5C907B2C9268A6F52",
                            0, 4000);
}

// Verify that the host reservation is found and used. Lease host name and
// FQDN should be the reservation hostname suffixed by the qualifying suffix.
TEST_F(FqdnDhcpv6SrvTest, hostnameReservationSuffix) {
    isc::dhcp::test::IfaceMgrTestConfig test_config(true);

    string config_str = "{ "
        "\"interfaces-config\": {"
        "  \"interfaces\": [ \"*\" ]"
        "},"
        "\"valid-lifetime\": 4000, "
        "\"preferred-lifetime\": 3000,"
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet6\": [ "
        " { "
        "    \"id\": 1, \n"
        "    \"subnet\": \"2001:db8:1::/48\", "
        "    \"pools\": [ { \"pool\": \"2001:db8:1:1::/64\" } ],"
        "    \"interface\": \"eth0\" , "
        "   \"reservations\": ["
        "    {"
        "        \"duid\": \"" + duid_->toText() + "\","
        "        \"ip-addresses\": [ \"2001:db8:1:1::babe\" ],"
        "        \"hostname\": \"alice\""
        "    }"
        "    ]"
        " } ],"
        " \"ddns-qualifying-suffix\": \"example.com\", "
        " \"dhcp-ddns\": {"
        "     \"enable-updates\": true }"
        "}";

    configure(config_str);

    // Update subnet_ and pool_ members after config
    setSubnetAndPool(0, 0, Lease::TYPE_NA);

    ASSERT_NO_THROW(srv_->startD2());

    ASSERT_TRUE(CfgMgr::instance().ddnsEnabled());

    // Verify that the host reservation is found and lease name/FQDN are
    // formed properly from the host name and qualifying suffix.
    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "alice.example.com.", 1, IOAddress("2001:db8:1:1::babe"));

    // Verify that NameChangeRequest is correct.
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::babe",
                            "000201E2EB74FB53A5778E74AFD43870ECA5"
                            "4150B1F52B0CFED434802DA1259D6D3CA4",
                            0, 4000, "alice.example.com.");
}

// Verify that the host reservation is found and used, rather than dynamic
// Address.  Lease host name and FQDN should be the reservation hostname
// without a qualifying suffix.
TEST_F(FqdnDhcpv6SrvTest, hostnameReservationNoSuffix) {
    isc::dhcp::test::IfaceMgrTestConfig test_config(true);

    string config_str = "{ "
        "\"interfaces-config\": {"
        "  \"interfaces\": [ \"*\" ]"
        "},"
        "\"valid-lifetime\": 4000, "
        "\"preferred-lifetime\": 3000,"
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet6\": [ "
        " { "
        "    \"id\": 1, \n"
        "    \"subnet\": \"2001:db8:1::/48\", "
        "    \"pools\": [ { \"pool\": \"2001:db8:1:1::/64\" } ],"
        "    \"interface\": \"eth0\" , "
        "   \"reservations\": ["
        "    {"
        "        \"duid\": \"" + duid_->toText() + "\","
        "        \"ip-addresses\": [ \"2001:db8:1:1::babe\" ],"
        "        \"hostname\": \"alice.example.com\""
        "    }"
        "    ]"
        " } ],"
        " \"ddns-qualifying-suffix\": \"\", "
        " \"dhcp-ddns\": {"
        "     \"enable-updates\": true }"
        "}";

    configure(config_str);
    // Update subnet_ and pool_ members after config
    setSubnetAndPool(0, 0, Lease::TYPE_NA);

    ASSERT_NO_THROW(srv_->startD2());

    ASSERT_TRUE(CfgMgr::instance().ddnsEnabled());

    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "alice.example.com.", 1,
                       IOAddress("2001:db8:1:1::babe"));

    // Verify that NameChangeRequest is correct.
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                            "2001:db8:1:1::babe",
                            "000201E2EB74FB53A5778E74AFD43870ECA5"
                            "4150B1F52B0CFED434802DA1259D6D3CA4",
                            0, 4000, "alice.example.com.");
}

TEST_F(FqdnDhcpv6SrvTest, hostnameReservationDdnsDisabled) {
    isc::dhcp::test::IfaceMgrTestConfig test_config(true);

    string config_str = "{ "
        "\"interfaces-config\": {"
        "  \"interfaces\": [ \"*\" ]"
        "},"
        "\"valid-lifetime\": 4000, "
        "\"preferred-lifetime\": 3000,"
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet6\": [ "
        " { "
        "    \"id\": 1, \n"
        "    \"subnet\": \"2001:db8:1::/48\", "
        "    \"pools\": [ { \"pool\": \"2001:db8:1:1::/64\" } ],"
        "    \"interface\": \"eth0\" , "
        "    \"reservations\": ["
        "    {"
        "        \"duid\": \"" + duid_->toText() + "\","
        "        \"ip-addresses\": [ \"2001:db8:1:1::babe\" ],"
        "        \"hostname\": \"alice\""
        "    }"
        "    ]"
        " } ],"
        " \"ddns-qualifying-suffix\": \"disabled.example.com\", "
        " \"dhcp-ddns\": {"
        "     \"enable-updates\": false }"
        "}";

    configure(config_str);

    // Update subnet_ and pool_ members after config
    setSubnetAndPool(0, 0, Lease::TYPE_NA);

    ASSERT_FALSE(CfgMgr::instance().ddnsEnabled());

    testProcessMessage(DHCPV6_REQUEST, "myhost.example.com",
                       "alice.disabled.example.com.", 0,
                       IOAddress("2001:db8:1:1::babe"));
}

// Verifies that the ddns-replace-client-name behavior is correct for each of
// the supported modes.
TEST_F(FqdnDhcpv6SrvTest, replaceClientNameModeTest) {
    isc::dhcp::test::IfaceMgrTestConfig test_config(true);

    testReplaceClientNameMode("never",
                              CLIENT_NAME_NOT_PRESENT, NAME_NOT_REPLACED);

    testReplaceClientNameMode("never",
                              CLIENT_NAME_PRESENT, NAME_NOT_REPLACED);

    testReplaceClientNameMode("always",
                              CLIENT_NAME_NOT_PRESENT, NAME_REPLACED);
    testReplaceClientNameMode("always",
                              CLIENT_NAME_PRESENT, NAME_REPLACED);

    testReplaceClientNameMode("when-present",
                              CLIENT_NAME_NOT_PRESENT, NAME_NOT_REPLACED);
    testReplaceClientNameMode("when-present",
                              CLIENT_NAME_PRESENT, NAME_REPLACED);

    testReplaceClientNameMode("when-not-present",
                              CLIENT_NAME_NOT_PRESENT, NAME_REPLACED);
    testReplaceClientNameMode("when-not-present",
                              CLIENT_NAME_PRESENT, NAME_NOT_REPLACED);
}

// Verifies that setting hostname-char-set sanitizes FQDN option
// values received from clients.
TEST_F(FqdnDhcpv6SrvTest, sanitizeFqdn) {
    // Verify a full FQDN with no invalid chars is left alone
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S,
             "myhost.example.com",
             Option6ClientFqdn::FULL, Option6ClientFqdn::FLAG_S,
             "myhost.example.com.", false);

    // Verify that a partial FQDN with no invalid chars is left alone
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S,
             "myhost",
             Option6ClientFqdn::PARTIAL, Option6ClientFqdn::FLAG_S,
             "myhost.example.com.", false);

    // Verify that a full FQDN with invalid chars is cleaned.
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S,
             "m%y*host.example.com",
             Option6ClientFqdn::FULL, Option6ClientFqdn::FLAG_S,
             "mxyxhost.example.com.", false);

    // Verify that a partial FQDN with invalid chars is cleaned.
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S,
             "m%y*host",
             Option6ClientFqdn::PARTIAL, Option6ClientFqdn::FLAG_S,
             "mxyxhost.example.com.", false);

    // Verify that a full FQDN with nul chars is cleaned.
    testFqdn(DHCPV6_SOLICIT, Option6ClientFqdn::FLAG_S,
             std::string("m\000yhost.exa\000mple.com", 20),
             Option6ClientFqdn::FULL, Option6ClientFqdn::FLAG_S,
             "mxyhost.exaxmple.com.", false);
}

// Verifies that scoped ddns-parameter handling.
// Specifically that D2 can be enabled with sending updates
// disabled globally, and enabled at the subnet level.
TEST_F(FqdnDhcpv6SrvTest, ddnsScopeTest) {
    std::string config_str =
    "{ \"interfaces-config\": {\n"
        "  \"interfaces\": [ \"*\" ]\n"
        "},\n"
        "\"preferred-lifetime\": 3000,\n"
        "\"rebind-timer\": 2000,\n"
        "\"renew-timer\": 1000,\n"
        "\"ddns-send-updates\": false,\n"
        "\"subnet6\": [ {\n"
        "    \"id\": 1, \n"
        "    \"subnet\": \"2001:db8:1::/48\",\n"
        "    \"pools\": [ { \"pool\": \"2001:db8:1::1 - 2001:db8:1::10\" } ],\n"
        "    \"interface\": \"eth0\"\n"
        " },\n"
        " {\n"
        "    \"id\": 2, \n"
        "    \"subnet\": \"2001:db8:2::/48\",\n"
        "    \"pools\": [ { \"pool\": \"2001:db8:2::1 - 2001:db8:2::10\" } ],\n"
        "    \"interface\": \"eth1\",\n"
        "    \"ddns-send-updates\": true\n"
        " } ],\n"
        "\"valid-lifetime\": 4000,\n"
        " \"dhcp-ddns\": {\n"
        "     \"enable-updates\": true\n"
        " }\n"
    "}";

    Dhcp6Client client1(srv_);
    client1.setInterface("eth0");

    // Load a configuration with D2 enabled
    ASSERT_NO_FATAL_FAILURE(configure(config_str, *client1.getServer()));
    ASSERT_TRUE(CfgMgr::instance().ddnsEnabled());
    ASSERT_NO_THROW(client1.getServer()->startD2());

    // Include the Client FQDN option.
    ASSERT_NO_THROW(client1.useFQDN(Option6ClientFqdn::FLAG_S, "one.example.org.",
                                    Option6ClientFqdn::FULL));

    // Now send the DHCPREQUEST with including the FQDN option.
    ASSERT_NO_THROW(client1.doSARR());
    Pkt6Ptr resp = client1.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    Option6ClientFqdnPtr fqdn;
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("one.example.org.", fqdn->getDomainName());

    // ddns-send-updates for subnet 1 should be off, so we should NOT have an NRC.
    ASSERT_EQ(0, CfgMgr::instance().getD2ClientMgr().getQueueSize());

    // Now let's try with a client on subnet 2.
    Dhcp6Client client2(srv_);
    client2.setInterface("eth1");
    client2.requestAddress();

    // Include the Client FQDN option.
    ASSERT_NO_THROW(client2.useFQDN(Option6ClientFqdn::FLAG_S, "two.example.org.",
                                    Option6ClientFqdn::FULL));

    ASSERT_NO_THROW(client2.doSARR());
    resp = client2.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("two.example.org.", fqdn->getDomainName());

    Subnet6Ptr subnet = (CfgMgr::instance().getCurrentCfg()->getCfgSubnets6()->getSubnet(2));
    ASSERT_TRUE(subnet);
    DdnsParamsPtr p = (CfgMgr::instance().getCurrentCfg()->getDdnsParams(subnet));
    ASSERT_TRUE(p->getEnableUpdates());

    // ddns-send-updates for subnet 2 are enabled, verify the NCR is correct.
    ASSERT_EQ(1, CfgMgr::instance().getD2ClientMgr().getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true, "2001:db8:2::1",
                            "", 0, 4000);
}

// Verifies that the DDNS parameters used for a lease in subnet in
// a shared-network belong to lease's subnet.  This checks that we
// get the right results even when the allocation engine changes the
// subnet chosen.  The configuration is two 1-address pool subnets in
// a shared-network. The first will do a SARR, which consumes the first
// pool. This should cause the allocation engine to dynamically select
// the second subnet for the second client.  The subnets define different
// values for qualifying suffixes, thus making it simple to verify
// the appropriate subnet parameters are used.  Both clients then
// renew their leases.
TEST_F(FqdnDhcpv6SrvTest, ddnsSharedNetworkTest) {
    std::string config_str =
    "{ \"interfaces-config\": { \n"
        "  \"interfaces\": [ \"*\" ] \n"
        "}, \n"
        "\"preferred-lifetime\": 3000, \n"
        "\"rebind-timer\": 2000, \n"
        "\"renew-timer\": 1000, \n"
        "\"valid-lifetime\": 4000, \n"
        "\"shared-networks\": [ \n"
        "{ \n"
            "\"name\": \"frog\", \n"
            "\"interface\": \"eth0\", \n"
            "\"subnet6\": [ { \n"
                "\"id\": 1, \n"
                "\"subnet\": \"2001:db8:1::/64\", \n"
                "\"pools\": [ { \"pool\": \"2001:db8:1::1 - 2001:db8:1::1\" } ], \n"
                "\"interface\": \"eth0\", \n"
                "\"ddns-qualifying-suffix\": \"one.example.com.\" \n"
            " }, \n"
            " { \n"
                "\"id\": 2, \n"
                "\"subnet\": \"2001:db8:2::/64\", \n"
                "\"pools\": [ { \"pool\": \"2001:db8:2::1 - 2001:db8:2::1\" } ], \n"
                "\"interface\": \"eth0\", \n"
                "\"ddns-qualifying-suffix\": \"two.example.com.\" \n"
            " } ] \n"
        "} ], \n"
        "\"ddns-send-updates\": true, \n"
        "\"dhcp-ddns\": { \n"
        "     \"enable-updates\": true \n"
        " } \n"
    "}";

    Dhcp6Client client1(srv_);
    client1.setInterface("eth0");
    client1.requestAddress();

    // Load a configuration with D2 enabled
    ASSERT_NO_FATAL_FAILURE(configure(config_str, *client1.getServer()));
    ASSERT_TRUE(CfgMgr::instance().ddnsEnabled());
    ASSERT_NO_THROW(client1.getServer()->startD2());

    // Include the Client FQDN option.
    ASSERT_NO_THROW(client1.useFQDN(Option6ClientFqdn::FLAG_S, "client1",
                                    Option6ClientFqdn::PARTIAL));

    // Now do a SARR.
    ASSERT_NO_THROW(client1.doSARR());
    Pkt6Ptr resp = client1.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    Option6ClientFqdnPtr fqdn;
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("client1.one.example.com.", fqdn->getDomainName());

    // ddns-send-updates for subnet 1 are enabled, verify the NCR is correct.
    ASSERT_EQ(1, CfgMgr::instance().getD2ClientMgr().getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true, "2001:db8:1::1",
                            "", 0, 4000, "client1.one.example.com.");

    // Make sure the lease hostname and fqdn flags are correct.
    Lease6Ptr lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                            IOAddress("2001:db8:1::1"));
    ASSERT_TRUE(lease);
    EXPECT_EQ("client1.one.example.com.", lease->hostname_);
    EXPECT_TRUE(lease->fqdn_fwd_);
    EXPECT_TRUE(lease->fqdn_rev_);

    // Now let's try with a different client. Subnet 1 is full so we should get an
    // address from subnet 2.
    Dhcp6Client client2(srv_);
    client2.setInterface("eth0");
    client2.requestAddress();

    // Include the Client FQDN option.
    ASSERT_NO_THROW(client2.useFQDN(Option6ClientFqdn::FLAG_S, "client2",
                                    Option6ClientFqdn::PARTIAL));

    // Do a SARR.
    ASSERT_NO_THROW(client2.doSARR());
    resp = client2.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("client2.two.example.com.", fqdn->getDomainName());

    // ddns-send-updates for subnet 2 are enabled, verify the NCR is correct.
    ASSERT_EQ(1, CfgMgr::instance().getD2ClientMgr().getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true, "2001:db8:2::1",
                            "", 0, 4000, "client2.two.example.com.");

    // Make sure the lease hostname and fqdn flags are correct.
    lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA, IOAddress("2001:db8:2::1"));
    ASSERT_TRUE(lease);
    EXPECT_EQ("client2.two.example.com.", lease->hostname_);
    EXPECT_TRUE(lease->fqdn_fwd_);
    EXPECT_TRUE(lease->fqdn_rev_);

    // Now let's check Renewals
    // First we'll renew a client2.
    ASSERT_NO_THROW(client2.doRenew());
    resp = client2.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("client2.two.example.com.", fqdn->getDomainName());

    // ddns-send-updates for subnet 2 are enabled, but currently a renew/rebind does
    // not update, unless the FQDN or flags change.
    ASSERT_EQ(0, CfgMgr::instance().getD2ClientMgr().getQueueSize());

    // Make sure the lease hostname is still correct.
    lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA, IOAddress("2001:db8:2::1"));
    ASSERT_TRUE(lease);
    EXPECT_EQ("client2.two.example.com.", lease->hostname_);

    // Next we'll renew client1
    ASSERT_NO_THROW(client1.doRenew());
    resp = client1.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("client1.one.example.com.", fqdn->getDomainName());

    // ddns-send-updates for subnet 1 are enabled, but currently a renew/rebind does
    // not update, unless the FQDN or flags change.
    ASSERT_EQ(0, CfgMgr::instance().getD2ClientMgr().getQueueSize());

    // Make sure the lease hostname and fqdn flags are correct.
    lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA, IOAddress("2001:db8:1::1"));
    ASSERT_TRUE(lease);
    EXPECT_EQ("client1.one.example.com.", lease->hostname_);
    EXPECT_TRUE(lease->fqdn_fwd_);
    EXPECT_TRUE(lease->fqdn_rev_);
}

// Verifies lease and NCR content (or lack of NCRs) are correct when
// subnets in a shared-network define different values for send-ddns-updates
// This checks that we get the right results even when the allocation engine
// changes the subnet chosen.  The configuration is two 1-address pool subnets in
// a shared-network. The first client will do a SARR, which consumes the first
// pool. This should cause the allocation engine to dynamically select
// the second subnet for the second client.
TEST_F(FqdnDhcpv6SrvTest, ddnsSharedNetworkTest2) {
    std::string config_str =
    "{ \"interfaces-config\": { \n"
        "  \"interfaces\": [ \"*\" ] \n"
        "}, \n"
        "\"preferred-lifetime\": 3000, \n"
        "\"rebind-timer\": 2000, \n"
        "\"renew-timer\": 1000, \n"
        "\"valid-lifetime\": 4000, \n"
        "\"shared-networks\": [ \n"
        "{ \n"
            "\"name\": \"frog\", \n"
            "\"interface\": \"eth0\", \n"
            "\"subnet6\": [ { \n"
                "\"id\": 1, \n"
                "\"subnet\": \"2001:db8:1::/64\", \n"
                "\"pools\": [ { \"pool\": \"2001:db8:1::1 - 2001:db8:1::1\" } ], \n"
                "\"interface\": \"eth0\", \n"
                "\"ddns-qualifying-suffix\": \"one.example.com.\", \n"
                "\"ddns-send-updates\": true \n"
            " }, \n"
            " { \n"
                "\"id\": 2, \n"
                "\"subnet\": \"2001:db8:2::/64\", \n"
                "\"pools\": [ { \"pool\": \"2001:db8:2::1 - 2001:db8:2::1\" } ], \n"
                "\"interface\": \"eth0\", \n"
                "\"ddns-qualifying-suffix\": \"two.example.com.\", \n"
                "\"ddns-send-updates\": false \n"
            " } ] \n"
        "} ], \n"
        "\"dhcp-ddns\": { \n"
        "     \"enable-updates\": true \n"
        " } \n"
    "}";

    Dhcp6Client client1(srv_);
    client1.setInterface("eth0");
    client1.requestAddress();

    // Load a configuration with D2 enabled
    ASSERT_NO_FATAL_FAILURE(configure(config_str, *client1.getServer()));
    ASSERT_TRUE(CfgMgr::instance().ddnsEnabled());
    ASSERT_NO_THROW(client1.getServer()->startD2());

    // Include the Client FQDN option.
    ASSERT_NO_THROW(client1.useFQDN(Option6ClientFqdn::FLAG_S, "client1",
                                    Option6ClientFqdn::PARTIAL));

    // Now do a SARR.
    ASSERT_NO_THROW(client1.doSARR());
    Pkt6Ptr resp = client1.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    Option6ClientFqdnPtr fqdn;
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("client1.one.example.com.", fqdn->getDomainName());

    // ddns-send-updates for subnet 1 are enabled, verify the NCR is correct.
    ASSERT_EQ(1, CfgMgr::instance().getD2ClientMgr().getQueueSize());
    verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true, "2001:db8:1::1",
                            "", 0, 4000, "client1.one.example.com.");

    // Make sure the lease hostname and fdqn flags are correct.
    Lease6Ptr lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                            IOAddress("2001:db8:1::1"));
    ASSERT_TRUE(lease);
    EXPECT_EQ("client1.one.example.com.", lease->hostname_);
    EXPECT_TRUE(lease->fqdn_fwd_);
    EXPECT_TRUE(lease->fqdn_rev_);

    // Now let's try with a different client. Subnet 1 is full so we should get an
    // address from subnet 2.
    Dhcp6Client client2(srv_);
    client2.setInterface("eth0");
    client2.requestAddress();

    // Include the Client FQDN option.
    ASSERT_NO_THROW(client2.useFQDN(Option6ClientFqdn::FLAG_S, "client2",
                                    Option6ClientFqdn::PARTIAL));

    // Do a SARR.
    ASSERT_NO_THROW(client2.doSARR());
    resp = client2.getContext().response_;
    ASSERT_TRUE(resp);
    ASSERT_EQ(DHCPV6_REPLY, static_cast<int>(resp->getType()));

    // Check that the response FQDN is as expected.
    fqdn = boost::dynamic_pointer_cast<Option6ClientFqdn>(resp->getOption(D6O_CLIENT_FQDN));
    ASSERT_TRUE(fqdn);
    EXPECT_EQ("client2.two.example.com.", fqdn->getDomainName());

    // ddns-send-updates for subnet 2 are disabled, verify there is no NCR.
    ASSERT_EQ(0, CfgMgr::instance().getD2ClientMgr().getQueueSize());

    // Make sure the lease hostname and fdqn flags are correct.
    lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA, IOAddress("2001:db8:2::1"));
    ASSERT_TRUE(lease);
    EXPECT_EQ("client2.two.example.com.", lease->hostname_);
    EXPECT_FALSE(lease->fqdn_fwd_);
    EXPECT_FALSE(lease->fqdn_rev_);
}

// Verifies that renews only generate NCRs if the situation dictates
// that it should. It checks:
//
// -# enable-updates true or false
// -# update-on-renew true or false
// -# Whether or not the FQDN has changed between old and new lease
TEST_F(FqdnDhcpv6SrvTest, processRequestRenew) {
    std::string fqdn1 = "one.example.com.";
    std::string fqdn2 = "two.example.com.";
    struct Scenario {
        std::string description_;
        bool send_updates_;
        bool update_on_renew_;
        std::string old_fqdn_;
        std::string new_fqdn_;
        size_t remove_;
        size_t add_;
    };

    // Mnemonic constants.
    const bool send_updates = true;
    const bool update_on_renew = true;
    const size_t remove = 1;
    const size_t add = 1;

    const std::vector<Scenario> scenarios = {
        {
        "#1 update-on-renew false, no change in fqdn",
        send_updates, !update_on_renew, fqdn1, fqdn1, !remove, !add
        },
        {
        "#2 update-on-renew is false, change in fqdn",
        send_updates, !update_on_renew, fqdn1, fqdn2, remove, add
        },
        {
        "#3 update-on-renew is true, no change in fqdn",
        send_updates, update_on_renew, fqdn1, fqdn1, remove, add
        },
        {
        "#4 update-on-renew is true, change in fqdn",
        send_updates, update_on_renew, fqdn1, fqdn2, remove, add
        },
        // All prior scenarios test with send-updates true.  We really
        // only need one with it false.
        {
        "#5 send-updates false, update-on-renew is true, change in fqdn",
        !send_updates, update_on_renew, fqdn1, fqdn2, !remove, !add
        }
    };

    enableD2();
    subnet_->setDdnsReplaceClientNameMode(D2ClientConfig::RCM_NEVER);

    // Iterate over test scenarios.
    for (auto const& scenario : scenarios) {
        SCOPED_TRACE(scenario.description_); {
            // Make sure the lease does not exist.
            ASSERT_FALSE(LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                               IOAddress("2001:db8:1:1::dead:beef")));
            // Set and verify DDNS params flags
            subnet_->setDdnsSendUpdates(scenario.send_updates_);
            subnet_->setDdnsUpdateOnRenew(scenario.update_on_renew_);

            ASSERT_EQ(scenario.send_updates_, getDdnsParams()->getEnableUpdates());
            ASSERT_EQ(scenario.update_on_renew_, getDdnsParams()->getUpdateOnRenew());

            // Create the "old" lease
            testProcessMessage(DHCPV6_REQUEST, scenario.old_fqdn_, scenario.old_fqdn_);

            // The lease should have been recorded in the database.
            Lease6Ptr old_lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                                        IOAddress("2001:db8:1:1::dead:beef"));
            ASSERT_TRUE(old_lease);

            if (!scenario.send_updates_ || scenario.old_fqdn_.empty()) {
                // We should not have an NCR.
                ASSERT_EQ(0, d2_mgr_.getQueueSize());
            } else {
                // We should have an NCR add.
                ASSERT_EQ(1, d2_mgr_.getQueueSize());
                verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                                        old_lease->addr_.toText(), "",
                                        0, old_lease->valid_lft_,
                                        old_lease->hostname_);
            }

            // Now let's renew (or create) the lease.
            testProcessMessage(DHCPV6_RENEW, scenario.new_fqdn_, scenario.new_fqdn_);

            // The lease should have been recorded in the database.
            Lease6Ptr new_lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                                        IOAddress("2001:db8:1:1::dead:beef"));
            ASSERT_TRUE(new_lease);

            // Verify queue count is correct.
            ASSERT_EQ((scenario.remove_ + scenario.add_), d2_mgr_.getQueueSize());

            // If we expect a remove, check it.
            if (scenario.remove_ > 0) {
                // Verify NCR content
                verifyNameChangeRequest(isc::dhcp_ddns::CHG_REMOVE, true, true,
                                        old_lease->addr_.toText(), "",
                                        0, old_lease->valid_lft_,
                                        old_lease->hostname_);
            }

            // If we expect an add, check it.
            if (scenario.add_ > 0) {
                // Verify NCR content
                verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                                        new_lease->addr_.toText(), "",
                                        0, new_lease->valid_lft_,
                                        new_lease->hostname_);
            }

            // Now delete the lease.
            bool deleted = false;
            ASSERT_NO_THROW(deleted = LeaseMgrFactory::instance().deleteLease(new_lease));
            ASSERT_TRUE(deleted);
        }
    }
}

// Verify the ddns-ttl-percent is used when specified.
TEST_F(FqdnDhcpv6SrvTest, ddnsTtlPercentTest) {
    testDdnsTtlParameters(2100, 0.5);
}

// Verify the ddns-ttl is used when specified.
TEST_F(FqdnDhcpv6SrvTest, ddnsTtlTest) {
    testDdnsTtlParameters(2100,                     // valid lft
                          Optional<double>(),       // percent
                          999,                      // ttl
                          Optional<uint32_t>(),     // min
                          Optional<uint32_t>());    // max
}

// Verify the ddns-ttl-min is used when specified.
TEST_F(FqdnDhcpv6SrvTest, ddnsTtlMinTest) {
    testDdnsTtlParameters(2100,                     // valid lft
                          Optional<double>(),       // percent
                          Optional<uint32_t>(),     // ttl
                          800,                      // ttl-min
                          Optional<uint32_t>());    // ttl-max
}

// Verify the ddns-ttl-max is used when specified.
TEST_F(FqdnDhcpv6SrvTest, ddnsTtlMaxTest) {
    testDdnsTtlParameters(2100,                     // valid lft
                          Optional<double>(),       // percent
                          Optional<uint32_t>(),     // ttl
                          Optional<uint32_t>(),     // ttl-min
                          500);                     // ttl-max
}

// Verify pool-level DDNS parameters are used.
// We don't verify all of them, just enough
// enough to ensure proper scoping of values.
TEST_F(FqdnDhcpv6SrvTest, poolDdnsParametersTest) {

    // A configuration with following pools:
    // 1. Specifies a qualifying suffix
    // 2. Specifies no DDNS parameters
    // 3. Disables DDNS updates
    // 4. Specifies a qualifying suffix but disables DDNS updates
    std::string config = R"(
    {
        "interfaces-config": { "interfaces": [ "*" ] },
        "dhcp-ddns": { "enable-updates": true },
        "valid-lifetime": 4000,
        "preferred-lifetime": 3000,
        "rebind-timer": 2000,
        "renew-timer": 1000,
        "subnet6": [{
            "subnet": "2001:db8::/64",
            "interface": "eth0",
            "id": 1,
            "ddns-qualifying-suffix": "subfix.com",
            "pools": [{
                "pool": "2001:db8::1-2001:db8::1",
                "ddns-qualifying-suffix": "poolfix.com",
            },
            {
                "pool": "2001:db8::2-2001:db8::2",
            },
            {
                "pool": "2001:db8::3-2001:db8::3",
                "ddns-send-updates": false
            },
            {
                "pool": "2001:db8::4-2001:db8::4",
                "ddns-qualifying-suffix": "pool4fix.com",
                "ddns-send-updates": false
            }]
          }]
    })";

    // Load the configuration with D2 enabled.
    ASSERT_NO_FATAL_FAILURE(configure(config));
    ASSERT_TRUE(CfgMgr::instance().ddnsEnabled());
    ASSERT_NO_THROW(srv_->startD2());

    struct Scenario {
        std::vector<uint8_t> raw_duid_;
        IOAddress expected_address_;
        std::string client_fqdn_;
        std::string expected_fqdn_;
        bool expect_ncr_;
        std::string expected_dhcid_;
    };

    std::list<Scenario> scenarios = {
    {
        { 0x01, 0x01, 0x01, 0x01 },
        IOAddress("2001:db8::1"),
        "myhost",
        "myhost.poolfix.com.",
        true,
        "0002019572DE453862C45A48A5F8498C440BC8A3038B89CFA93E5E1ABACA7599EFDDE9"
    },
    {
        { 0x02, 0x02, 0x02, 0x02 },
        IOAddress("2001:db8::2"),
        "myhost",
        "myhost.subfix.com.",
        true,
        "000201EB88CE3092CF3F22758AD0AAA19CD5C10B3F45EC1883601F586A48E6E3768EE0"
    },
    {
        { 0x03, 0x03, 0x03, 0x03 },
        IOAddress("2001:db8::3"),
        "myhost",
        "myhost.subfix.com.",
        false,
        ""
    },
    {
        { 0x04, 0x04, 0x04, 0x04 },
        IOAddress("2001:db8::4"),
        "myhost",
        "myhost.pool4fix.com.",
        false,
        ""
    }};

    for (auto const& scenario : scenarios) {
        // Build a REQUEST per the scenario.
        Pkt6Ptr query = Pkt6Ptr(new Pkt6(DHCPV6_REQUEST, 1234));
        query->setIface("eth0");
        query->setIndex(ETH0_INDEX);

        // Add the client id.
        OptionPtr client_id(new Option(Option::V6, D6O_CLIENTID,
                            scenario.raw_duid_));
        query->addOption(client_id);
        query->addOption(srv_->getServerID());

        // Add an IA requesting the expected address.
        Option6IAPtr ia = generateIA(D6O_IA_NA, 234, 1500, 3000);
        OptionPtr hint_opt(new Option6IAAddr(D6O_IAADDR,
                                             scenario.expected_address_,
                                             300, 500));
        ia->addOption(hint_opt);
        query->addOption(ia);

        // Add an FQDN option. We set it to partial to ensure we qualify
        // it with a suffix.
        query->addOption(createClientFqdn(Option6ClientFqdn::FLAG_S,
                                          scenario.client_fqdn_,
                                          Option6ClientFqdn::PARTIAL));

        // Process the REQUEST.
        Pkt6Ptr reply;
        AllocEngine::ClientContext6 ctx;
        bool drop = !srv_->earlyGHRLookup(query, ctx);
        ASSERT_FALSE(drop);
        ctx.subnet_ = srv_->selectSubnet(query, drop);
        ASSERT_FALSE(drop);
        srv_->initContext(ctx, drop);
        ASSERT_FALSE(drop);
        ASSERT_NO_THROW(reply = srv_->processRequest(ctx));
        checkResponse(reply, DHCPV6_REPLY, 1234);

        // Fetch the IA_NA from response.
        OptionPtr tmp = reply->getOption(D6O_IA_NA);
        ASSERT_TRUE(tmp);
        ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
        ASSERT_TRUE(ia);

        // Check that we got the address we requested.
        tmp = ia->getOption(D6O_IAADDR);
        boost::shared_ptr<Option6IAAddr> addr
            = boost::dynamic_pointer_cast<Option6IAAddr>(tmp);
        ASSERT_TRUE(addr);
        EXPECT_EQ(addr->getAddress(), scenario.expected_address_);

        // Check that the lease exists with the correct FDQN.
        Lease6Ptr lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                                addr->getAddress());
        ASSERT_TRUE(lease);
        EXPECT_EQ(lease->hostname_, scenario.expected_fqdn_);

        // Verify the FQDN in the response is correct.
        Option6ClientFqdnPtr fqdn;
        ASSERT_TRUE(fqdn = boost::dynamic_pointer_cast<
                        Option6ClientFqdn>(reply->getOption(D6O_CLIENT_FQDN)));
        EXPECT_EQ(fqdn->getDomainName(), scenario.expected_fqdn_);

        // Verify the NCR if we expect one.
        if (!scenario.expect_ncr_) {
            ASSERT_EQ(0, d2_mgr_.getQueueSize());
        } else {
            ASSERT_EQ(1, d2_mgr_.getQueueSize());
            verifyNameChangeRequest(isc::dhcp_ddns::CHG_ADD, true, true,
                                    scenario.expected_address_.toText(),
                                    scenario.expected_dhcid_,
                                    0, 4000,
                                    scenario.expected_fqdn_);
        }
    }
}

} // end of anonymous namespace
