// Copyright (C) 2013-2026 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 <gtest/gtest.h>

#include <cc/command_interpreter.h>
#include <config/unix_command_config.h>
#include <dhcp/option6_status_code.h>
#include <dhcp/testutils/pkt_captures.h>
#include <dhcpsrv/cfg_multi_threading.h>
#include <dhcp6/tests/dhcp6_client.h>
#include <dhcp6/tests/dhcp6_test_utils.h>
#include <dhcp6/json_config_parser.h>
#include <log/logger_support.h>
#include <process/log_parser.h>
#include <stats/stats_mgr.h>
#include <util/filesystem.h>
#include <util/pointer_util.h>

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <sstream>

using namespace isc::data;
using namespace isc::dhcp;
using namespace isc::asiolink;
using namespace isc::stats;
using namespace isc::util;
using namespace isc::process;
using namespace isc::config;
using namespace boost::posix_time;

namespace isc {
namespace dhcp {
namespace test {

const char* BaseServerTest::DUID_FILE = "kea-dhcp6-serverid";

BaseServerTest::BaseServerTest() {
    isc::dhcp::CfgMgr::instance().clear();
    CfgMgr::instance().setFamily(AF_INET6);
    original_datadir_ = CfgMgr::instance().getDataDir();
    CfgMgr::instance().getDataDir(true, TEST_DATA_BUILDDIR);
    resetLogPath();
    resetSocketPath();
    file::PathChecker::enableEnforcement(true);
}

BaseServerTest::~BaseServerTest() {
    // Remove test DUID file.
    std::ostringstream s;
    s << CfgMgr::instance().getDataDir() << "/" << DUID_FILE;
    static_cast<void>(::remove(s.str().c_str()));

    // Remove default lease file.
    std::ostringstream s2;
    s2 << CfgMgr::instance().getDataDir() << "/kea-leases6.csv";
    static_cast<void>(::remove(s2.str().c_str()));

    // Revert to original data directory.
    CfgMgr::instance().getDataDir(true, original_datadir_);

    // Revert to unit test logging, in case the test reconfigured it.
    isc::log::initLogger();
    resetLogPath();
    resetSocketPath();
    file::PathChecker::enableEnforcement(true);
}

void
BaseServerTest::setLogTestPath(const std::string explicit_path /* = "" */) {
    LogConfigParser::getLogPath(true, (!explicit_path.empty() ?
                                       explicit_path : TEST_DATA_BUILDDIR));
}

void
BaseServerTest::resetLogPath() {
    LogConfigParser::getLogPath(true);
}

void
BaseServerTest::setSocketTestPath(const std::string explicit_path /* = "" */) {
    UnixCommandConfig::getSocketPath(true,
                                     (!explicit_path.empty() ?
                                     explicit_path : TEST_DATA_BUILDDIR));

    auto path = UnixCommandConfig::getSocketPath();
    UnixCommandConfig::setSocketPathPerms(file::getPermissions(path));
}

void
BaseServerTest::resetSocketPath() {
    UnixCommandConfig::getSocketPath(true);
    UnixCommandConfig::setSocketPathPerms();
}

Dhcpv6SrvTest::Dhcpv6SrvTest()
    : NakedDhcpv6SrvTest(), srv_(new NakedDhcpv6Srv(0)), multi_threading_(false) {
    subnet_ = Subnet6::create(isc::asiolink::IOAddress("2001:db8:1::"),
                              48, 1000, 2000, 3000, 4000, SubnetID(1));
    subnet_->setIface("eth0");

    pool_ = isc::dhcp::Pool6Ptr(new isc::dhcp::Pool6(isc::dhcp::Lease::TYPE_NA,
                                isc::asiolink::IOAddress("2001:db8:1:1::"),
                                64));
    subnet_->addPool(pool_);

    isc::dhcp::CfgMgr::instance().clear();
    CfgMgr::instance().setFamily(AF_INET6);
    isc::dhcp::CfgMgr::instance().getStagingCfg()->getCfgSubnets6()->add(subnet_);
    isc::dhcp::CfgMgr::instance().commit();

    // configure PD pool
    pd_pool_ = isc::dhcp::Pool6Ptr(new isc::dhcp::Pool6(isc::dhcp::Lease::TYPE_PD,
                                   isc::asiolink::IOAddress("2001:db8:1:2::"),
                                   64, 80));
    subnet_->addPool(pd_pool_);

    // Reset the thread pool.
    MultiThreadingMgr::instance().apply(false, 0, 0);
}

Dhcpv6SrvTest::~Dhcpv6SrvTest() {
    isc::dhcp::CfgMgr::instance().clear();

    // Reset the thread pool.
    MultiThreadingMgr::instance().apply(false, 0, 0);
};

// Checks that server response (ADVERTISE or REPLY) contains proper IA_NA option
// It returns IAADDR option for each chaining with checkIAAddr method.
boost::shared_ptr<Option6IAAddr>
Dhcpv6SrvTest::checkIA_NA(const Pkt6Ptr& rsp, uint32_t expected_iaid,
                          uint32_t expected_t1, uint32_t expected_t2) {
    OptionPtr tmp = rsp->getOption(D6O_IA_NA);
    // Can't use ASSERT_TRUE() in method that returns something
    if (!tmp) {
        ADD_FAILURE() << "IA_NA option not present in response";
        return (boost::shared_ptr<Option6IAAddr>());
    }

    boost::shared_ptr<Option6IA> ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
    if (!ia) {
        ADD_FAILURE() << "IA_NA cannot convert option ptr to Option6";
        return (boost::shared_ptr<Option6IAAddr>());
    }

    if (expected_iaid != ia->getIAID()) {
        ADD_FAILURE() << "ia->iaid: " << ia->getIAID()
                      << " is not expected value: " << expected_iaid;
        return (boost::shared_ptr<Option6IAAddr>());
    }

    if (expected_t1 != ia->getT1()) {
        ADD_FAILURE() << "ia->t1: " << ia->getT1()
                      << " is not expected value: " << expected_t1;
        return (boost::shared_ptr<Option6IAAddr>());
    }

    if (expected_t2 != ia->getT2()) {
        ADD_FAILURE() << "ia->t2: " << ia->getT2()
                      << " is not expected value: " << expected_t2;
        return (boost::shared_ptr<Option6IAAddr>());
    }

    tmp = ia->getOption(D6O_IAADDR);
    boost::shared_ptr<Option6IAAddr> addr = boost::dynamic_pointer_cast<Option6IAAddr>(tmp);
    return (addr);
}

boost::shared_ptr<Option6IAPrefix>
Dhcpv6SrvTest::checkIA_PD(const Pkt6Ptr& rsp, uint32_t expected_iaid,
                          uint32_t expected_t1, uint32_t expected_t2) {
    OptionPtr tmp = rsp->getOption(D6O_IA_PD);
    // Can't use ASSERT_TRUE() in method that returns something
    if (!tmp) {
        ADD_FAILURE() << "IA_PD option not present in response";
        return (boost::shared_ptr<Option6IAPrefix>());
    }

    boost::shared_ptr<Option6IA> ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
    if (!ia) {
        ADD_FAILURE() << "IA_PD cannot convert option ptr to Option6";
        return (boost::shared_ptr<Option6IAPrefix>());
    }

    EXPECT_EQ(expected_iaid, ia->getIAID());
    EXPECT_EQ(expected_t1, ia->getT1());
    EXPECT_EQ(expected_t2, ia->getT2());

    tmp = ia->getOption(D6O_IAPREFIX);
    boost::shared_ptr<Option6IAPrefix> addr = boost::dynamic_pointer_cast<Option6IAPrefix>(tmp);
    return (addr);
}

// Checks if the lease sent to client is present in the database
// and is valid when checked against the configured subnet
Lease6Ptr
Dhcpv6SrvTest::checkLease(const DuidPtr& duid, const OptionPtr& ia_na,
                          boost::shared_ptr<Option6IAAddr> addr) {
    boost::shared_ptr<Option6IA> ia = boost::dynamic_pointer_cast<Option6IA>(ia_na);

    Lease6Ptr lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_NA,
                                                            addr->getAddress());
    if (!lease) {
        std::cout << "Lease for " << addr->getAddress()
                  << " not found in the database backend.";
        return (Lease6Ptr());
    }

    EXPECT_EQ(addr->getAddress(), lease->addr_);
    EXPECT_TRUE(*lease->duid_ == *duid);
    EXPECT_EQ(ia->getIAID(), lease->iaid_);
    EXPECT_EQ(subnet_->getID(), lease->subnet_id_);

    return (lease);
}

isc::dhcp::Lease6Ptr
Dhcpv6SrvTest::checkLease(const isc::dhcp::Lease6& lease) {
    Lease6Ptr lease_db = LeaseMgrFactory::instance().getLease6(lease.type_,
                                                               lease.addr_);
    if (!lease_db) {
        return (Lease6Ptr());
    }

    EXPECT_TRUE(util::nullOrEqualValues(lease_db->hwaddr_, lease.hwaddr_));
    EXPECT_TRUE(util::nullOrEqualValues(lease_db->duid_, lease.duid_));

    return (lease_db);
}

Lease6Ptr
Dhcpv6SrvTest::checkPdLease(const DuidPtr& duid, const OptionPtr& ia_pd,
                            boost::shared_ptr<Option6IAPrefix> prefix){
    boost::shared_ptr<Option6IA> ia = boost::dynamic_pointer_cast<Option6IA>(ia_pd);

    Lease6Ptr lease = LeaseMgrFactory::instance().getLease6(Lease::TYPE_PD,
                                                            prefix->getAddress());
    if (!lease) {
        std::cout << "PD lease for " << prefix->getAddress()
                  << " not found in the database backend.";
        return (Lease6Ptr());
    }

    EXPECT_EQ(prefix->getAddress(), lease->addr_);
    EXPECT_TRUE(*lease->duid_ == *duid);
    EXPECT_EQ(ia->getIAID(), lease->iaid_);
    EXPECT_EQ(subnet_->getID(), lease->subnet_id_);

    return (lease);
}

Pkt6Ptr
Dhcpv6SrvTest::createMessage(uint8_t message_type, Lease::Type lease_type,
                             const IOAddress& addr, const uint8_t prefix_len,
                             const uint32_t iaid) {
    Pkt6Ptr msg = Pkt6Ptr(new Pkt6(message_type, 1234));
    msg->setRemoteAddr(IOAddress("fe80::abcd"));
    msg->setIface("eth0");
    msg->setIndex(ETH0_INDEX);
    msg->addOption(createIA(lease_type, addr, prefix_len, iaid));
    return (msg);
}

Option6IAPtr
Dhcpv6SrvTest::createIA(isc::dhcp::Lease::Type lease_type,
                        const isc::asiolink::IOAddress& addr,
                        const uint8_t prefix_len, const uint32_t iaid) {
    uint16_t code;
    OptionPtr subopt;
    switch (lease_type) {
    case Lease::TYPE_NA:
        code = D6O_IA_NA;
        subopt.reset(new Option6IAAddr(D6O_IAADDR, addr, 300, 500));
        break;
    case Lease::TYPE_PD:
        code = D6O_IA_PD;
        subopt.reset(new Option6IAPrefix(D6O_IAPREFIX, addr, prefix_len,
                                         300, 500));
        break;
    default:
        isc_throw(BadValue, "Invalid lease type specified "
                  << static_cast<int>(lease_type));
    }

    Option6IAPtr ia = generateIA(code, iaid, 1500, 3000);
    ia->addOption(subopt);

    return (ia);
}

void
Dhcpv6SrvTest::testRenewBasic(Lease::Type type,
                              const std::string& existing_addr,
                              const std::string& renew_addr,
                              const uint8_t prefix_len,
                              bool insert_before_renew,
                              bool expire_before_renew,
                              uint32_t hint_pref,
                              uint32_t hint_valid,
                              uint32_t expected_pref,
                              uint32_t expected_valid) {
    const IOAddress existing(existing_addr);
    const IOAddress renew(renew_addr);
    const uint32_t iaid = 234;

    // To reuse an expired lease we need a subnet with a pool that
    // consists of exactly one address. This address will get expired
    // and then be reused.
    if (expire_before_renew) {
        CfgMgr::instance().clear();
        subnet_ = Subnet6::create(IOAddress("2001:db8:1:1::"), 48,
                                  1000, 2000, 3000, 4000, subnet_->getID());
        subnet_->setIface("eth0");
        pool_.reset(new Pool6(Lease::TYPE_NA, existing, existing));
        subnet_->addPool(pool_);
        CfgMgr::instance().setFamily(AF_INET6);
        CfgMgr::instance().getStagingCfg()->getCfgSubnets6()->add(subnet_);
        CfgMgr::instance().commit();
    }

    // Use intervals for lifetimes for lifetime tests.
    if (hint_pref != 300 || hint_valid != 500) {
        subnet_->setPreferred(Triplet<uint32_t>(2000, 3000, 4000));
        subnet_->setValid(Triplet<uint32_t>(3000, 4000, 5000));
    }

    // Generate client-id also duid_
    OptionPtr clientid = generateClientId();

    // Check that the address we are about to use is indeed in pool
    ASSERT_TRUE(subnet_->inPool(type, existing));

    Lease6Ptr l;
    if (insert_before_renew) {
        // Note that preferred, valid, T1 and T2 timers and CLTT are set to invalid
        // value on purpose. They should be updated during RENEW.
        Lease6Ptr lease(new Lease6(type, existing, duid_, iaid, 501, 502,
                                   subnet_->getID(), HWAddrPtr(), prefix_len));
        lease->cltt_ = 1234;
        ASSERT_TRUE(LeaseMgrFactory::instance().addLease(lease));

        // Check that the lease is really in the database
        l = LeaseMgrFactory::instance().getLease6(type, existing);
        ASSERT_TRUE(l);

        // Check that preferred, valid and cltt really set and not using
        // previous (500, 501, etc.) values
        EXPECT_NE(l->preferred_lft_, subnet_->getPreferred());
        EXPECT_NE(l->valid_lft_, subnet_->getValid());
        EXPECT_NE(l->cltt_, time(NULL));
    }

    if (expire_before_renew) {
        // The lease must exist.
        ASSERT_TRUE(l);

        // Change the subnet identifier to make the allocation engine to
        // not treat the lease as being renewed by the same client,
        // but to treat it as expired lease to be reused.
        ++l->subnet_id_;

        // Move the cllt back in time and make sure that the lease got expired.
        l->cltt_ = time(NULL) - 10;
        l->valid_lft_ = 5;
        ASSERT_TRUE(l->expired());
        // Update the lease in the lease database.
        LeaseMgrFactory::instance().updateLease6(l);
    }

    Pkt6Ptr req;
    uint8_t message_type = DHCPV6_RENEW;
    // Use a request vs a renew for getting an expired lease without
    // extending it. i.e. not call extendLease6 after reuseExpiredLease.
    if (expire_before_renew) {
        message_type = DHCPV6_REQUEST;
    }

    if (hint_pref == 300 && hint_valid == 500) {
        req = createMessage(message_type, type, IOAddress(renew_addr),
                            prefix_len, iaid);
    } else {
        // from createMessage
        req.reset(new Pkt6(message_type, 1234));
        req->setRemoteAddr(IOAddress("fe80::abcd"));
        req->setIface("eth0");
        req->setIndex(ETH0_INDEX);

        // from createIA
        uint16_t code;
        OptionPtr subopt;
        switch (type) {
        case Lease::TYPE_NA:
            code = D6O_IA_NA;
            subopt.reset(new Option6IAAddr(D6O_IAADDR,
                                           IOAddress(renew_addr),
                                           hint_pref, hint_valid));
            break;
        case Lease::TYPE_PD:
            code = D6O_IA_PD;
            subopt.reset(new Option6IAPrefix(D6O_IAPREFIX,
                                             IOAddress(renew_addr), prefix_len,
                                             hint_pref, hint_valid));
            break;
        default:
            isc_throw(BadValue, "Invalid lease type specified "
                      << static_cast<int>(type));
        }

        Option6IAPtr ia = generateIA(code, iaid, 1500, 3000);
        ia->addOption(subopt);
        req->addOption(ia);
    };
    req->addOption(clientid);
    req->addOption(srv_->getServerID());

    // Pass it to the server and hope for a REPLY
    Pkt6Ptr reply;
    if (!expire_before_renew) {
        reply = srv_->processRenew(req);
    } else {
        reply = srv_->processRequest(req);
    }

    // Check if we get response at all
    checkResponse(reply, DHCPV6_REPLY, 1234);

    // Check DUIDs
    checkServerId(reply, srv_->getServerID());
    checkClientId(reply, clientid);

    switch (type) {
    case Lease::TYPE_NA: {
        // Check that IA_NA was returned and that there's an address included
        boost::shared_ptr<Option6IAAddr>
          addr_opt = checkIA_NA(reply, 234, subnet_->getT1(), subnet_->getT2());

        ASSERT_TRUE(addr_opt);

        // Check that we've got the address we requested
        checkIAAddr(addr_opt, renew, Lease::TYPE_NA,
                    expected_pref, expected_valid);

        // Check that the lease is really in the database
        l = checkLease(duid_, reply->getOption(D6O_IA_NA), addr_opt);
        ASSERT_TRUE(l);
        break;
    }

    case Lease::TYPE_PD: {
        // Check that IA_NA was returned and that there's an address included
        boost::shared_ptr<Option6IAPrefix> prefix_opt
            = checkIA_PD(reply, 234, subnet_->getT1(), subnet_->getT2());

        ASSERT_TRUE(prefix_opt);

        // Check that we've got the address we requested
        checkIAAddr(prefix_opt, renew, Lease::TYPE_PD,
                    expected_pref, expected_valid);
        EXPECT_EQ(pd_pool_->getLength(), prefix_opt->getLength());

        // Check that the lease is really in the database
        l = checkPdLease(duid_, reply->getOption(D6O_IA_PD), prefix_opt);
        ASSERT_TRUE(l);
        break;
    }
    default:
        isc_throw(BadValue, "Invalid lease type");
    }

    // Check that preferred, valid and cltt were really updated
    EXPECT_EQ(expected_pref ? expected_pref : subnet_->getPreferred().get(),
              l->preferred_lft_);
    EXPECT_EQ(expected_valid ? expected_valid : subnet_->getValid().get(),
              l->valid_lft_);

    // Checking for CLTT is a bit tricky if we want to avoid off by 1 errors
    int32_t cltt = static_cast<int32_t>(l->cltt_);
    int32_t expected = static_cast<int32_t>(time(NULL));
    // equality or difference by 1 between cltt and expected is ok.
    EXPECT_GE(1, abs(cltt - expected));

    Lease6Ptr lease = LeaseMgrFactory::instance().getLease6(type,
                                                            IOAddress(renew_addr));
    EXPECT_TRUE(LeaseMgrFactory::instance().deleteLease(lease));
}

void
Dhcpv6SrvTest::testRenewWrongIAID(Lease::Type type, const IOAddress& addr) {
    const uint32_t transid = 1234;
    const uint32_t valid_iaid = 234;
    const uint32_t bogus_iaid = 456;

    uint8_t prefix_len = (type != Lease::TYPE_PD) ? 128 : pd_pool_->getLength();

    // Quick sanity check that the address we're about to use is ok
    ASSERT_TRUE(subnet_->inPool(type, addr));

    // Check that the lease is NOT in the database
    Lease6Ptr l = LeaseMgrFactory::instance().getLease6(type, addr);
    ASSERT_FALSE(l);

    // GenerateClientId() also sets duid_
    OptionPtr clientid = generateClientId();

    // Note that preferred, valid, T1 and T2 timers and CLTT are set to invalid
    // value on purpose. They should be updated during RENEW.
    Lease6Ptr lease(new Lease6(type, addr, duid_, valid_iaid,
                               501, 502, subnet_->getID(),
                               HWAddrPtr(), prefix_len));
    ASSERT_TRUE(LeaseMgrFactory::instance().addLease(lease));

    // Pass it to the server and hope for a REPLY
    // Let's create a RENEW
    Pkt6Ptr renew = createMessage(DHCPV6_RENEW, type, IOAddress(addr), prefix_len,
                                  bogus_iaid);
    renew->addOption(clientid);
    renew->addOption(srv_->getServerID());

    // The duid and address matches, but the iaid is different. The server could
    // respond with NoBinding. However, according to
    // draft-ietf-dhc-dhcpv6-stateful-issues-10, the server can also assign a
    // new address. And that's what we expect here.
    Pkt6Ptr reply = srv_->processRenew(renew);
    checkResponse(reply, DHCPV6_REPLY, transid);

    // Check that IA_NA was returned and that there's an address included
    boost::shared_ptr<Option6IAAddr>
        addr_opt = checkIA_NA(reply, bogus_iaid, subnet_->getT1(), subnet_->getT2());

    ASSERT_TRUE(addr_opt);

    // Check that we've got the an address
    checkIAAddr(addr_opt, addr_opt->getAddress(), Lease::TYPE_NA);

    // Check that we got a different address than was in the database.
    EXPECT_NE(addr_opt->getAddress().toText(), addr.toText());

    // Check that the lease is really in the database
    l = checkLease(duid_, reply->getOption(D6O_IA_NA), addr_opt);
    ASSERT_TRUE(l);
}

void
Dhcpv6SrvTest::testRenewSomeoneElsesLease(Lease::Type type, const IOAddress& addr) {
    const uint32_t valid_iaid = 234;
    const uint32_t transid = 1234;

    uint8_t prefix_len = (type != Lease::TYPE_PD) ? 128 : pd_pool_->getLength();

    // GenerateClientId() also sets duid_
    OptionPtr clientid = generateClientId();

    // Let's create a lease.
    Lease6Ptr lease(new Lease6(type, addr, duid_, valid_iaid,
                               501, 502, subnet_->getID(),
                               HWAddrPtr(), prefix_len));
    ASSERT_TRUE(LeaseMgrFactory::instance().addLease(lease));

    // CASE 3: Lease belongs to a client with different client-id
    Pkt6Ptr renew = createMessage(DHCPV6_RENEW, type, IOAddress(addr), prefix_len,
                                  valid_iaid);
    renew->addOption(generateClientId(13)); // generate different DUID (length 13)
    renew->addOption(srv_->getServerID());

    // The iaid and address matches, but the duid is different.
    // The server should not renew it, but assign something else.
    Pkt6Ptr reply = srv_->processRenew(renew);
    checkResponse(reply, DHCPV6_REPLY, transid);
    OptionPtr tmp = reply->getOption(D6O_IA_NA);
    ASSERT_TRUE(tmp);

    // Check that IA_?? was returned and that there's proper status code
    // Check that IA_NA was returned and that there's an address included
    boost::shared_ptr<Option6IAAddr>
        addr_opt = checkIA_NA(reply, valid_iaid, subnet_->getT1(), subnet_->getT2());

    ASSERT_TRUE(addr_opt);

    // Check that we've got the an address
    checkIAAddr(addr_opt, addr_opt->getAddress(), Lease::TYPE_NA);

    // Check that we got a different address than was in the database.
    EXPECT_NE(addr_opt->getAddress().toText(), addr.toText());

    // Check that the lease is really in the database
    Lease6Ptr l = checkLease(duid_, reply->getOption(D6O_IA_NA), addr_opt);
    ASSERT_TRUE(l);
}

void
Dhcpv6SrvTest::testReleaseBasic(Lease::Type type, const IOAddress& existing,
                                const IOAddress& release_addr,
                                const LeaseAffinity lease_affinity) {
    if (lease_affinity == LEASE_AFFINITY_DISABLED) {
        auto expiration_cfg = CfgMgr::instance().getCurrentCfg()->getCfgExpiration();
        expiration_cfg->setFlushReclaimedTimerWaitTime(0);
        expiration_cfg->setHoldReclaimedTime(0);
    }
    const uint32_t iaid = 234;

    uint32_t code; // option code of the container (IA_NA or IA_PD)
    uint8_t prefix_len;
    if (type == Lease::TYPE_NA) {
        code = D6O_IA_NA;
        prefix_len = 128;
    } else if (type == Lease::TYPE_PD) {
        code = D6O_IA_PD;
        prefix_len = pd_pool_->getLength();
    } else {
        isc_throw(BadValue, "Invalid lease type");
    }

    // Generate client-id also duid_
    OptionPtr clientid = generateClientId();

    // Check that the address we are about to use is indeed in pool
    ASSERT_TRUE(subnet_->inPool(type, existing));

    // Let's prepopulate the database
    Lease6Ptr lease(new Lease6(type, existing, duid_, iaid,
                               501, 502, subnet_->getID(),
                               HWAddrPtr(), prefix_len));
    ASSERT_TRUE(LeaseMgrFactory::instance().addLease(lease));

    // Check that the lease is really in the database
    Lease6Ptr l = LeaseMgrFactory::instance().getLease6(type, existing);
    ASSERT_TRUE(l);

    // And prepopulate the stats counter
    StatsMgr::instance().setValue(type == Lease::TYPE_NA ?
                                  "assigned-nas" : "assigned-pds",
                                  static_cast<int64_t>(1));

    std::string name = StatsMgr::generateName("subnet", subnet_->getID(),
                                              type == Lease::TYPE_NA ?
                                              "assigned-nas" : "assigned-pds");
    StatsMgr::instance().setValue(name, static_cast<int64_t>(1));

    ObservationPtr stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);

    // Let's create a RELEASE
    Pkt6Ptr rel = createMessage(DHCPV6_RELEASE, type, release_addr, prefix_len,
                                iaid);
    rel->addOption(clientid);
    rel->addOption(srv_->getServerID());

    // Pass it to the server and hope for a REPLY
    Pkt6Ptr reply = srv_->processRelease(rel);

    // Check if we get response at all
    checkResponse(reply, DHCPV6_REPLY, 1234);

    OptionPtr tmp = reply->getOption(code);
    ASSERT_TRUE(tmp);

    // Check that IA_NA was returned and that there's an address included
    boost::shared_ptr<Option6IA> ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
    checkIA_NAStatusCode(ia, STATUS_Success, 0, 0);
    checkMsgStatusCode(reply, STATUS_Success);

    // There should be no address returned in RELEASE (see RFC 8415, 18.3.7)
    // There should be no prefix
    EXPECT_FALSE(tmp->getOption(D6O_IAADDR));
    EXPECT_FALSE(tmp->getOption(D6O_IAPREFIX));

    // Check DUIDs
    checkServerId(reply, srv_->getServerID());
    checkClientId(reply, clientid);

    if (lease_affinity == LEASE_AFFINITY_DISABLED) {
        // Check that the lease is really gone in the database
        // get lease by address
        l = LeaseMgrFactory::instance().getLease6(type, release_addr);
        ASSERT_FALSE(l);

        // get lease by subnetid/duid/iaid combination
        l = LeaseMgrFactory::instance().getLease6(type, *duid_, iaid,
                                                  subnet_->getID());
        ASSERT_FALSE(l);
    } else {
        l = LeaseMgrFactory::instance().getLease6(type, release_addr);
        ASSERT_TRUE(l);

        EXPECT_EQ(l->valid_lft_, 0);
        EXPECT_EQ(l->preferred_lft_, 0);

        EXPECT_EQ(Lease6::STATE_RELEASED, l->state_);

        // get lease by subnetid/duid/iaid combination
        l = LeaseMgrFactory::instance().getLease6(type, *duid_, iaid,
                                                  subnet_->getID());
        ASSERT_TRUE(l);

        EXPECT_EQ(l->valid_lft_, 0);
        EXPECT_EQ(l->preferred_lft_, 0);
        EXPECT_EQ(Lease::STATE_RELEASED, l->state_);
    }

    // We should have decremented the address counter
    stat = StatsMgr::instance().getObservation(type == Lease::TYPE_NA ?
                                               "assigned-nas" : "assigned-pds");
    ASSERT_TRUE(stat);
    EXPECT_EQ(0, stat->getInteger().first);

    stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);
    EXPECT_EQ(0, stat->getInteger().first);
}

void
Dhcpv6SrvTest::testReleaseAndReclaim(Lease::Type type) {
    IfaceMgrTestConfig iface_mgr_test_config(true);

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

    // Configure DHCP server.
    const char* RELEASE_CONFIG = {
    // Configuration 0
        "{ \"interfaces-config\": {"
            "  \"interfaces\": [ \"*\" ]"
            "},"
            "\"preferred-lifetime\": 3,"
            "\"rebind-timer\": 2, "
            "\"renew-timer\": 1, "
            "\"subnet6\": [ { "
            "    \"id\": 1, "
            "    \"pools\": [ { \"pool\": \"2001:db8:1::/64\" } ],"
            "    \"pd-pools\": [ { \"prefix\": \"2001:db8:2::\", \"delegated-len\": 64, \"prefix-len\": 48 } ],"
            "    \"subnet\": \"2001:db8::/32\", "
            "    \"interface-id\": \"\","
            "    \"interface\": \"eth0\""
            " } ],"
            "\"valid-lifetime\": 4,"
            " \"expired-leases-processing\": {"
            "    \"flush-reclaimed-timer-wait-time\": 3,"
            "    \"hold-reclaimed-time\": 1,"
            "    \"max-reclaim-leases\": 100,"
            "    \"max-reclaim-time\": 250,"
            "    \"reclaim-timer-wait-time\": 1,"
            "    \"unwarned-reclaim-cycles\": 5"
            "},"
            "\"multi-threading\": { \"enable-multi-threading\": false }"
        "}"
    };

    isc::dhcp::CfgMgr::instance().clear();
    CfgMgr::instance().setFamily(AF_INET6);

    setenv("KEA_LFC_EXECUTABLE", KEA_LFC_EXECUTABLE, 1);
    ConstElementPtr json;
    try {
        json = parseJSON(RELEASE_CONFIG);
    } catch (const std::exception& ex) {
        // Fatal failure on parsing error
        FAIL() << "parsing failure:"
               << "config:" << RELEASE_CONFIG << std::endl
               << "error: " << ex.what();
    }

    disableIfacesReDetect(json);

    client.getServer()->processConfig(json);

    CfgMgr::instance().commit();

    const uint32_t iaid = 234;

    uint32_t code; // option code of the container (IA_NA or IA_PD)
    uint8_t prefix_len;
    if (type == Lease::TYPE_NA) {
        code = D6O_IA_NA;
        prefix_len = 128;
        client.requestAddress(iaid);
    } else if (type == Lease::TYPE_PD) {
        code = D6O_IA_PD;
        prefix_len = pd_pool_->getLength();
        client.requestPrefix(iaid);
    } else {
        isc_throw(BadValue, "Invalid lease type");
    }

    // Let's get the subnet-id and generate statistics name out of it
    const Subnet6Collection* subnets =
        CfgMgr::instance().getCurrentCfg()->getCfgSubnets6()->getAll();
    ASSERT_EQ(1, subnets->size());

    // And prepopulate the stats counter
    std::string name = StatsMgr::generateName("subnet", (*subnets->begin())->getID(),
                                              type == Lease::TYPE_NA ?
                                              "assigned-nas" : "assigned-pds");

    // Perform 4-way exchange.
    ASSERT_NO_THROW(client.doSARR());

    ObservationPtr stat = StatsMgr::instance().getObservation(type == Lease::TYPE_NA ?
                                                              "assigned-nas" : "assigned-pds");
    ASSERT_TRUE(stat);
    uint64_t global_before = stat->getInteger().first;

    stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);
    uint64_t subnet_before = stat->getInteger().first;

    // Make sure that the client has acquired NA lease.
    std::vector<Lease6> leases = client.getLeasesByType(type);
    ASSERT_EQ(1, leases.size());
    EXPECT_EQ(STATUS_Success, client.getStatusCode(iaid));

    // Let's create a RELEASE
    Pkt6Ptr rel = createMessage(DHCPV6_RELEASE, type, leases[0].addr_, prefix_len,
                                iaid);
    rel->addOption(client.getClientId());
    rel->addOption(srv_->getServerID());

    // Pass it to the server and hope for a REPLY
    Pkt6Ptr reply = srv_->processRelease(rel);

    // Check if we get response at all
    checkResponse(reply, DHCPV6_REPLY, 1234);

    OptionPtr tmp = reply->getOption(code);
    ASSERT_TRUE(tmp);

    // Check that IA_NA was returned and that there's an address included
    boost::shared_ptr<Option6IA> ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
    checkIA_NAStatusCode(ia, STATUS_Success, 0, 0);
    checkMsgStatusCode(reply, STATUS_Success);

    // There should be no address returned in RELEASE (see RFC 8415, 18.3.7)
    // There should be no prefix
    EXPECT_FALSE(tmp->getOption(D6O_IAADDR));
    EXPECT_FALSE(tmp->getOption(D6O_IAPREFIX));

    // Check DUIDs
    checkServerId(reply, srv_->getServerID());
    checkClientId(reply, client.getClientId());

    Lease6Ptr l = LeaseMgrFactory::instance().getLease6(type, leases[0].addr_);
    ASSERT_TRUE(l);

    EXPECT_EQ(l->valid_lft_, 0);
    EXPECT_EQ(l->preferred_lft_, 0);

    EXPECT_EQ(Lease6::STATE_RELEASED, l->state_);

    // get lease by subnetid/duid/iaid combination
    l = LeaseMgrFactory::instance().getLease6(type, *client.getDuid(), iaid,
                                              (*subnets->begin())->getID());
    ASSERT_TRUE(l);

    EXPECT_EQ(l->valid_lft_, 0);
    EXPECT_EQ(l->preferred_lft_, 0);
    EXPECT_EQ(Lease::STATE_RELEASED, l->state_);

    stat = StatsMgr::instance().getObservation(type == Lease::TYPE_NA ?
                                               "assigned-nas" : "assigned-pds");
    ASSERT_TRUE(stat);
    uint64_t global_after = stat->getInteger().first;
    ASSERT_EQ(global_after, global_before - 1);

    stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);
    uint64_t subnet_after = stat->getInteger().first;
    ASSERT_EQ(subnet_after, subnet_before - 1);
    sleep(1);
    client.getServer()->getIOService()->poll();

    l = LeaseMgrFactory::instance().getLease6(type, leases[0].addr_);
    ASSERT_TRUE(l);

    EXPECT_EQ(l->valid_lft_, 0);
    EXPECT_EQ(l->preferred_lft_, 0);

    EXPECT_EQ(Lease6::STATE_EXPIRED_RECLAIMED, l->state_);

    // get lease by subnetid/duid/iaid combination
    l = LeaseMgrFactory::instance().getLease6(type, *client.getDuid(), iaid,
                                              (*subnets->begin())->getID());
    ASSERT_TRUE(l);

    EXPECT_EQ(l->valid_lft_, 0);
    EXPECT_EQ(l->preferred_lft_, 0);
    EXPECT_EQ(Lease::STATE_EXPIRED_RECLAIMED, l->state_);

    stat = StatsMgr::instance().getObservation(type == Lease::TYPE_NA ?
                                               "assigned-nas" : "assigned-pds");
    ASSERT_TRUE(stat);
    uint64_t count = stat->getInteger().first;
    ASSERT_EQ(count, global_after);

    stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);
    count = stat->getInteger().first;
    ASSERT_EQ(count, subnet_after);
}

void
Dhcpv6SrvTest::testReleaseNoDelete(Lease::Type type, const IOAddress& addr,
                                   uint8_t qtype) {
    const uint32_t iaid = 234;

    uint8_t prefix_len = (type == Lease::TYPE_NA ? 128 : pd_pool_->getLength());

    // Generate client-id also duid_
    OptionPtr clientid = generateClientId();

    // Check that the address we are about to use is indeed in pool
    ASSERT_TRUE(subnet_->inPool(type, addr));

    // Let's prepopulate the database
    Lease6Ptr lease(new Lease6(type, addr, duid_, iaid,
                               501, 502, subnet_->getID(),
                               HWAddrPtr(), prefix_len));
    ASSERT_TRUE(LeaseMgrFactory::instance().addLease(lease));

    // Check that the lease is really in the database
    Lease6Ptr l = LeaseMgrFactory::instance().getLease6(type, addr);
    ASSERT_TRUE(l);

    // Let's create a RELEASE
    Pkt6Ptr rel = createMessage(DHCPV6_RELEASE, type, addr, prefix_len, iaid);
    rel->addOption(clientid);
    rel->addOption(srv_->getServerID());

    // Pass it to the server and hope for a REPLY
    Pkt6Ptr reply = srv_->processRelease(rel);

    // Check if we get response at all
    checkResponse(reply, DHCPV6_REPLY, 1234);
    checkMsgStatusCode(reply, STATUS_Success);

    // Check DUIDs
    checkServerId(reply, srv_->getServerID());
    checkClientId(reply, clientid);

    // Check lease
    l = LeaseMgrFactory::instance().getLease6(type, *duid_, iaid,
                                              subnet_->getID());
    ASSERT_TRUE(l);
    EXPECT_EQ(l->valid_lft_, 0);
    EXPECT_EQ(l->preferred_lft_, 0);

    // Create query
    Pkt6Ptr query;
    if (qtype != DHCPV6_SOLICIT) {
        query = createMessage(qtype, type, addr, prefix_len, iaid);
        query->addOption(srv_->getServerID());
    } else {
        query = createMessage(qtype, type, IOAddress::IPV6_ZERO_ADDRESS(),
                              prefix_len, iaid);
    }
    query->addOption(clientid);

    // Process query
    switch (qtype) {
    case DHCPV6_SOLICIT:
        reply = srv_->processSolicit(query);
        break;
    case DHCPV6_REQUEST:
        reply = srv_->processRequest(query);
        break;
    case DHCPV6_RENEW:
        reply = srv_->processRenew(query);
        break;
    case DHCPV6_REBIND:
        reply = srv_->processRebind(query);
        break;
    default:
        reply.reset();
        break;
    }

    // Check reply
    if (qtype == DHCPV6_SOLICIT) {
        checkResponse(reply, DHCPV6_ADVERTISE, 1234);
    } else {
        checkResponse(reply, DHCPV6_REPLY, 1234);
    }
    checkServerId(reply, srv_->getServerID());
    checkClientId(reply, clientid);
    checkMsgStatusCode(reply, STATUS_Success);
    if (type == Lease::TYPE_NA) {
        Option6IAAddrPtr iaaddr = checkIA_NA(reply, iaid, subnet_->getT1(),
                                             subnet_->getT2());
        ASSERT_TRUE(iaaddr);
        checkIAAddr(iaaddr, addr, type, subnet_->getPreferred(),
                    subnet_->getValid());
    } else {
        Option6IAPrefixPtr iapref = checkIA_PD(reply, iaid, subnet_->getT1(),
                                             subnet_->getT2());
        ASSERT_TRUE(iapref);
        checkIAAddr(iapref, addr, type, subnet_->getPreferred(),
                    subnet_->getValid());
    }

    // Check lease
    l = LeaseMgrFactory::instance().getLease6(type, *duid_, iaid,
                                              subnet_->getID());
    ASSERT_TRUE(l);
    if (qtype == DHCPV6_SOLICIT) {
        EXPECT_EQ(l->valid_lft_, 0);
        EXPECT_EQ(l->preferred_lft_, 0);
    } else {
        EXPECT_EQ(l->valid_lft_, subnet_->getValid());
        EXPECT_EQ(l->preferred_lft_, subnet_->getPreferred());
    }
}

void
Dhcpv6SrvTest::testReleaseReject(Lease::Type type, const IOAddress& addr) {
    const uint32_t transid = 1234;
    const uint32_t valid_iaid = 234;
    const uint32_t bogus_iaid = 456;

    uint32_t code; // option code of the container (IA_NA or IA_PD)
    uint8_t prefix_len;
    if (type == Lease::TYPE_NA) {
        code = D6O_IA_NA;
        prefix_len = 128;
    } else if (type == Lease::TYPE_PD) {
        code = D6O_IA_PD;
        prefix_len = pd_pool_->getLength();
    } else {
        isc_throw(BadValue, "Invalid lease type");
    }

    // Quick sanity check that the address we're about to use is ok
    ASSERT_TRUE(subnet_->inPool(type, addr));

    // GenerateClientId() also sets duid_
    OptionPtr clientid = generateClientId();

    // Pretend we have allocated 1 lease
    StatsMgr::instance().setValue(type == Lease::TYPE_NA ?
                                  "assigned-nas" : "assigned-pds",
                                  static_cast<int64_t>(1));

    std::string name = StatsMgr::generateName("subnet", subnet_->getID(),
                                              type == Lease::TYPE_NA ?
                                              "assigned-nas" : "assigned-pds");
    StatsMgr::instance().setValue(name, static_cast<int64_t>(1));

    // Check that the lease is NOT in the database
    Lease6Ptr l = LeaseMgrFactory::instance().getLease6(type, addr);
    ASSERT_FALSE(l);

    // Let's create a RELEASE
    Pkt6Ptr rel = createMessage(DHCPV6_RELEASE, type, addr, prefix_len, valid_iaid);
    rel->addOption(clientid);
    rel->addOption(srv_->getServerID());

    // Case 1: No lease known to server
    SCOPED_TRACE("CASE 1: No lease known to server");

    // Pass it to the server and hope for a REPLY
    Pkt6Ptr reply = srv_->processRelease(rel);

    // Check if we get response at all
    checkResponse(reply, DHCPV6_REPLY, transid);
    OptionPtr tmp = reply->getOption(code);
    ASSERT_TRUE(tmp);
    // Check that IA_NA/IA_PD was returned and that there's status code in it
    boost::shared_ptr<Option6IA> ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
    ASSERT_TRUE(ia);
    checkIA_NAStatusCode(ia, STATUS_NoBinding, 0, 0);
    checkMsgStatusCode(reply, STATUS_NoBinding);

    // Check that the lease is not there
    l = LeaseMgrFactory::instance().getLease6(type, addr);
    ASSERT_FALSE(l);

    // Verify we didn't decrement the stats counter
    ObservationPtr stat = StatsMgr::instance().getObservation(type == Lease::TYPE_NA ?
                                                              "assigned-nas" : "assigned-pds");
    ASSERT_TRUE(stat);
    EXPECT_EQ(1, stat->getInteger().first);

    stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);
    EXPECT_EQ(1, stat->getInteger().first);

    // CASE 2: Lease is known and belongs to this client, but to a different IAID
    SCOPED_TRACE("CASE 2: Lease is known and belongs to this client, but to a different IAID");

    Lease6Ptr lease(new Lease6(type, addr, duid_, valid_iaid, 501, 502,
                               subnet_->getID(), HWAddrPtr(), prefix_len));
    ASSERT_TRUE(LeaseMgrFactory::instance().addLease(lease));

    // Let's create a different RELEASE, with a bogus iaid
    rel = createMessage(DHCPV6_RELEASE, type, addr, prefix_len, bogus_iaid);
    rel->addOption(clientid);
    rel->addOption(srv_->getServerID());

    // Pass it to the server and hope for a REPLY
    reply = srv_->processRelease(rel);
    checkResponse(reply, DHCPV6_REPLY, transid);
    tmp = reply->getOption(code);
    ASSERT_TRUE(tmp);

    // Check that IA_?? was returned and that there's proper status code
    ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
    ASSERT_TRUE(ia);
    checkIA_NAStatusCode(ia, STATUS_NoBinding, 0, 0);
    checkMsgStatusCode(reply, STATUS_NoBinding);

    // Check that the lease is still there
    l = LeaseMgrFactory::instance().getLease6(type, addr);
    ASSERT_TRUE(l);

    // Verify we didn't decrement the stats counter
    stat = StatsMgr::instance().getObservation(type == Lease::TYPE_NA ?
                                               "assigned-nas" : "assigned-pds");
    ASSERT_TRUE(stat);
    EXPECT_EQ(1, stat->getInteger().first);

    stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);
    EXPECT_EQ(1, stat->getInteger().first);

    // CASE 3: Lease belongs to a client with different client-id
    SCOPED_TRACE("CASE 3: Lease belongs to a client with different client-id");

    rel->delOption(D6O_CLIENTID);
    ia = boost::dynamic_pointer_cast<Option6IA>(rel->getOption(code));
    ia->setIAID(valid_iaid); // Now iaid in renew matches that in leasemgr
    rel->addOption(generateClientId(13)); // generate different DUID
                                          // (with length 13)

    reply = srv_->processRelease(rel);
    checkResponse(reply, DHCPV6_REPLY, transid);
    tmp = reply->getOption(code);
    ASSERT_TRUE(tmp);

    // Check that IA_?? was returned and that there's proper status code
    ia = boost::dynamic_pointer_cast<Option6IA>(tmp);
    ASSERT_TRUE(ia);
    checkIA_NAStatusCode(ia, STATUS_NoBinding, 0, 0);
    checkMsgStatusCode(reply, STATUS_NoBinding);

    // Check that the lease is still there
    l = LeaseMgrFactory::instance().getLease6(type, addr);
    ASSERT_TRUE(l);

    // Verify we didn't decrement the stats counter
    stat = StatsMgr::instance().getObservation(type == Lease::TYPE_NA ?
                                               "assigned-nas" : "assigned-pds");
    ASSERT_TRUE(stat);
    EXPECT_EQ(1, stat->getInteger().first);

    stat = StatsMgr::instance().getObservation(name);
    ASSERT_TRUE(stat);
    EXPECT_EQ(1, stat->getInteger().first);

    // Finally, let's cleanup the database
    lease = LeaseMgrFactory::instance().getLease6(type, addr);
    EXPECT_TRUE(LeaseMgrFactory::instance().deleteLease(lease));
}

void
Dhcpv6SrvTest::testReceiveStats(uint8_t pkt_type, const std::string& stat_name) {

    StatsMgr& mgr = StatsMgr::instance();
    // Let's get a simple SOLICIT...
    Pkt6Ptr pkt = PktCaptures::captureSimpleSolicit();

    // And pretend it's packet of a different type
    pkt->data_[0] = pkt_type;

    // Check that the tested statistics is initially set to 0
    ObservationPtr pkt6_rcvd = mgr.getObservation("pkt6-received");
    ObservationPtr tested_stat = mgr.getObservation(stat_name);
    ASSERT_TRUE(pkt6_rcvd);
    ASSERT_TRUE(tested_stat);
    EXPECT_EQ(0, pkt6_rcvd->getInteger().first);
    EXPECT_EQ(0, tested_stat->getInteger().first);

    // Simulate that we have received that traffic
    srv_->fakeReceive(pkt);

    // Server will now process to run its normal loop, but instead of calling
    // IfaceMgr::receive6(), it will read all packets from the list set by
    // fakeReceive()
    srv_->run();

    // All expected statistics must be present.
    pkt6_rcvd = mgr.getObservation("pkt6-received");
    tested_stat = mgr.getObservation(stat_name);
    ASSERT_TRUE(pkt6_rcvd);
    ASSERT_TRUE(tested_stat);

    // They also must have expected values.
    EXPECT_EQ(1, pkt6_rcvd->getInteger().first);
    EXPECT_EQ(1, tested_stat->getInteger().first);
}

ConstElementPtr
Dhcpv6SrvTest::configure(Dhcpv6Srv& server, ConstElementPtr config) {
    ConstElementPtr const status(configureDhcp6Server(server, config));

    // Simulate the application of MT config such as in ControlledDhcpvXSrv::processConfig().
    CfgMultiThreading::apply(CfgMgr::instance().getStagingCfg()->getDHCPMultiThreading());

    return status;
}

void
Dhcpv6SrvTest::configure(const std::string& config,
                         const bool commit,
                         const bool open_sockets,
                         const bool create_managers,
                         const bool test,
                         const LeaseAffinity lease_affinity) {
    configure(config, *srv_, commit, open_sockets, create_managers, test,
              lease_affinity);
}

void
Dhcpv6SrvTest::configure(const std::string& config,
                         NakedDhcpv6Srv& srv,
                         const bool commit,
                         const bool open_sockets,
                         const bool create_managers,
                         const bool test,
                         const LeaseAffinity lease_affinity) {
    setenv("KEA_LFC_EXECUTABLE", KEA_LFC_EXECUTABLE, 1);
    MultiThreadingCriticalSection cs;
    ConstElementPtr json;
    try {
        json = parseJSON(config);
    } catch (const std::exception& ex) {
        // Fatal failure on parsing error
        FAIL() << "parsing failure:"
               << "config:" << config << std::endl
               << "error: " << ex.what();
    }

    ConstElementPtr status;

    // Disable the re-detect flag
    disableIfacesReDetect(json);

    // Set up multi-threading
    configureMultiThreading(multi_threading_, json);

    // Configure the server and make sure the config is accepted
    EXPECT_NO_THROW(status = configureDhcp6Server(srv, json, test));
    ASSERT_TRUE(status);
    int rcode;
    ConstElementPtr comment = isc::config::parseAnswer(rcode, status);
    ASSERT_EQ(0, rcode) << "configuration failed, test is broken: "
        << comment->str();

    // Use specified lease database backend.
    if (create_managers) {
        ASSERT_NO_THROW( {
            CfgDbAccessPtr cfg_db = CfgMgr::instance().getStagingCfg()->getCfgDbAccess();
            cfg_db->setAppendedParameters("universe=6");
            cfg_db->createManagers();
        } );
    }

    if (lease_affinity == LEASE_AFFINITY_DISABLED) {
        auto expiration_cfg = CfgMgr::instance().getStagingCfg()->getCfgExpiration();
        expiration_cfg->setFlushReclaimedTimerWaitTime(0);
        expiration_cfg->setHoldReclaimedTime(0);
    }

    try {
        CfgMgr::instance().getStagingCfg()->getCfgSubnets6()->initAllocatorsAfterConfigure();
    } catch (const std::exception& ex) {
        ADD_FAILURE() << "Error initializing the allocators after configure: "
            << ex.what();
    }

    try {
        CfgMultiThreading::apply(CfgMgr::instance().getStagingCfg()->getDHCPMultiThreading());
    } catch (const std::exception& ex) {
        ADD_FAILURE() << "Error applying multi threading settings: "
            << ex.what();
    }

    if (commit) {
        CfgMgr::instance().commit();
    }

    // Opening sockets.
    if (open_sockets) {
        IfaceMgr::instance().openSockets6();
    }
}

NakedDhcpv6SrvTest::NakedDhcpv6SrvTest()
    : rcode_(-1), start_time_(PktEvent::now()) {
    // it's ok if that fails. There should not be such a file anyway
    static_cast<void>(remove(DUID_FILE));

    const IfaceCollection& ifaces = IfaceMgr::instance().getIfaces();

    // There must be some interface detected
    if (ifaces.empty()) {
        // We can't use ASSERT in constructor
        ADD_FAILURE() << "No interfaces detected.";
    }

    valid_iface_ = (*ifaces.begin())->getName();
    valid_ifindex_ = (*ifaces.begin())->getIndex();

    // Let's wipe all existing statistics.
    StatsMgr::instance().removeAll();
}

NakedDhcpv6SrvTest::~NakedDhcpv6SrvTest() {
    // Let's wipe all existing statistics.
    isc::stats::StatsMgr::instance().removeAll();

    // Let's clean up if there is such a file.
    static_cast<void>(remove(DUID_FILE));
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("buffer6_receive");
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("buffer6_send");
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("lease6_renew");
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("lease6_release");
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("pkt6_receive");
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("pkt6_send");
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("subnet6_select");
    isc::hooks::HooksManager::preCalloutsLibraryHandle()
        .deregisterAllCallouts("addr6_register");
}

// Generate IA_NA option with specified parameters
boost::shared_ptr<Option6IA>
NakedDhcpv6SrvTest::generateIA(uint16_t type, uint32_t iaid, uint32_t t1,
                               uint32_t t2) {
    boost::shared_ptr<Option6IA> ia =
        boost::shared_ptr<Option6IA>(new Option6IA(type, iaid));
    ia->setT1(t1);
    ia->setT2(t2);
    return (ia);
}

void
NakedDhcpv6SrvTest::checkPktEvents(const PktPtr& msg,
                             std::list<std::string> expected_events) {
    ASSERT_NE(start_time_, PktEvent::EMPTY_TIME());
    auto events = msg->getPktEvents();
    ASSERT_EQ(events.size(), expected_events.size());
    ptime prev_time = start_time_;
    auto expected_event = expected_events.begin();
    for (const auto& event : events) {
        ASSERT_EQ(event.label_, *expected_event);
        EXPECT_GE(event.timestamp_, prev_time);
        prev_time = event.timestamp_;
        ++expected_event;
    }
}

bool
Dhcpv6SrvTest::compareOptions(const isc::dhcp::OptionPtr& option1,
                              const isc::dhcp::OptionPtr& option2) {
    if ((!option1 && option2) || (option1 && !option2)) {
        return (false);
    }
    if (!option1 && !option2) {
        return (true);
    }

    // We could start by comparing option codes and option lengths
    // here, but it's just a waste of time. These are tests, so they
    // don't have to be super performant. The pack+memcmp approach
    // verifies all in one go.

    isc::util::OutputBuffer buf1(0);
    isc::util::OutputBuffer buf2(0);

    option1->pack(buf1);
    option2->pack(buf2);

    if (buf1.getLength() != buf2.getLength()) {
        return (false);
    }

    // memcmp returns 0 when equal.
    return (!memcmp(buf1.getData(), buf2.getData(), buf1.getLength()));
}

void
NakedDhcpv6SrvTest::checkIA_NAStatusCode(
    const boost::shared_ptr<isc::dhcp::Option6IA>& ia,
    uint16_t expected_status_code, uint32_t expected_t1, uint32_t expected_t2,
    bool check_addr)
{
    // Make sure there is no address assigned. Depending on the situation,
    // the server will either not return the address at all and sometimes
    // it will return it with zeroed lifetimes.
    if (check_addr) {
        dhcp::OptionCollection options = ia->getOptions();
        for (auto const& opt : options) {
            if (opt.second->getType() != D6O_IAADDR) {
                continue;
            }

            dhcp::Option6IAAddrPtr addr =
                boost::dynamic_pointer_cast<isc::dhcp::Option6IAAddr>(opt.second);
            ASSERT_TRUE(addr);

            EXPECT_EQ(0, addr->getPreferred());
            EXPECT_EQ(0, addr->getValid());
        }
    }

    // T1, T2 should NOT be zeroed. draft-ietf-dhc-dhcpv6-stateful-issues-10,
    // section 4.4.6 says says that T1,T2 should be consistent along all
    // provided IA options.
    EXPECT_EQ(expected_t1, ia->getT1());
    EXPECT_EQ(expected_t2, ia->getT2());

    isc::dhcp::Option6StatusCodePtr status =
        boost::dynamic_pointer_cast<isc::dhcp::Option6StatusCode>
        (ia->getOption(D6O_STATUS_CODE));

    // It is ok to not include status success as this is the default
    // behavior
    if (expected_status_code == STATUS_Success && !status) {
        return;
    }

    EXPECT_TRUE(status);

    if (status) {
        // We don't have dedicated class for status code, so let's
        // just interpret first 2 bytes as status. Remainder of the
        // status code option content is just a text explanation
        // what went wrong.
        EXPECT_EQ(static_cast<uint16_t>(expected_status_code),
                  status->getStatusCode());
    }
}

}  // namespace test
}  // namespace dhcp
}  // namespace isc
