kea/src/lib/dhcpsrv/tests/cfgmgr_unittest.cc

// Copyright (C) 2012-2014 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

#include <config.h>

#include <dhcpsrv/cfgmgr.h>
#include <dhcpsrv/dhcp_parsers.h>
#include <exceptions/exceptions.h>
#include <dhcp/dhcp6.h>
#include <dhcp/tests/iface_mgr_test_config.h>

#include <gtest/gtest.h>

#include <iostream>
#include <sstream>

#include <arpa/inet.h>

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

// don't import the entire boost namespace.  It will unexpectedly hide uint8_t
// for some systems.
using boost::scoped_ptr;

namespace {

// This test verifies that BooleanStorage functions properly.
TEST(ValueStorageTest, BooleanTesting) {
    BooleanStorage testStore;

    // Verify that we can add and retrieve parameters.
    testStore.setParam("firstBool", false);
    testStore.setParam("secondBool", true);

    EXPECT_FALSE(testStore.getParam("firstBool"));
    EXPECT_TRUE(testStore.getParam("secondBool"));

    // Verify that we can update parameters.
    testStore.setParam("firstBool", true);
    testStore.setParam("secondBool", false);

    EXPECT_TRUE(testStore.getParam("firstBool"));
    EXPECT_FALSE(testStore.getParam("secondBool"));

    // Verify that we can delete a parameter and it will no longer be found.
    testStore.delParam("firstBool");
    EXPECT_THROW(testStore.getParam("firstBool"), isc::dhcp::DhcpConfigError);

    // Verify that the delete was safe and the store still operates.
    EXPECT_FALSE(testStore.getParam("secondBool"));

    // Verify that looking for a parameter that never existed throws.
    ASSERT_THROW(testStore.getParam("bogusBool"), isc::dhcp::DhcpConfigError);

    // Verify that attempting to delete a parameter that never existed does not throw.
    EXPECT_NO_THROW(testStore.delParam("bogusBool"));

    // Verify that we can empty the list.
    testStore.clear();
    EXPECT_THROW(testStore.getParam("secondBool"), isc::dhcp::DhcpConfigError);

}

// This test verifies that Uint32Storage functions properly.
TEST(ValueStorageTest, Uint32Testing) {
    Uint32Storage testStore;

    uint32_t intOne = 77;
    uint32_t intTwo = 33;

    // Verify that we can add and retrieve parameters.
    testStore.setParam("firstInt", intOne);
    testStore.setParam("secondInt", intTwo);

    EXPECT_EQ(testStore.getParam("firstInt"), intOne);
    EXPECT_EQ(testStore.getParam("secondInt"), intTwo);

    // Verify that we can update parameters.
    testStore.setParam("firstInt", --intOne);
    testStore.setParam("secondInt", ++intTwo);

    EXPECT_EQ(testStore.getParam("firstInt"), intOne);
    EXPECT_EQ(testStore.getParam("secondInt"), intTwo);

    // Verify that we can delete a parameter and it will no longer be found.
    testStore.delParam("firstInt");
    EXPECT_THROW(testStore.getParam("firstInt"), isc::dhcp::DhcpConfigError);

    // Verify that the delete was safe and the store still operates.
    EXPECT_EQ(testStore.getParam("secondInt"), intTwo);

    // Verify that looking for a parameter that never existed throws.
    ASSERT_THROW(testStore.getParam("bogusInt"), isc::dhcp::DhcpConfigError);

    // Verify that attempting to delete a parameter that never existed does not throw.
    EXPECT_NO_THROW(testStore.delParam("bogusInt"));

    // Verify that we can empty the list.
    testStore.clear();
    EXPECT_THROW(testStore.getParam("secondInt"), isc::dhcp::DhcpConfigError);
}

// This test verifies that StringStorage functions properly.
TEST(ValueStorageTest, StringTesting) {
    StringStorage testStore;

    std::string stringOne = "seventy-seven";
    std::string stringTwo = "thirty-three";

    // Verify that we can add and retrieve parameters.
    testStore.setParam("firstString", stringOne);
    testStore.setParam("secondString", stringTwo);

    EXPECT_EQ(testStore.getParam("firstString"), stringOne);
    EXPECT_EQ(testStore.getParam("secondString"), stringTwo);

    // Verify that we can update parameters.
    stringOne.append("-boo");
    stringTwo.append("-boo");

    testStore.setParam("firstString", stringOne);
    testStore.setParam("secondString", stringTwo);

    EXPECT_EQ(testStore.getParam("firstString"), stringOne);
    EXPECT_EQ(testStore.getParam("secondString"), stringTwo);

    // Verify that we can delete a parameter and it will no longer be found.
    testStore.delParam("firstString");
    EXPECT_THROW(testStore.getParam("firstString"), isc::dhcp::DhcpConfigError);

    // Verify that the delete was safe and the store still operates.
    EXPECT_EQ(testStore.getParam("secondString"), stringTwo);

    // Verify that looking for a parameter that never existed throws.
    ASSERT_THROW(testStore.getParam("bogusString"), isc::dhcp::DhcpConfigError);

    // Verify that attempting to delete a parameter that never existed does not throw.
    EXPECT_NO_THROW(testStore.delParam("bogusString"));

    // Verify that we can empty the list.
    testStore.clear();
    EXPECT_THROW(testStore.getParam("secondString"), isc::dhcp::DhcpConfigError);
}



class CfgMgrTest : public ::testing::Test {
public:
    CfgMgrTest() {
        // make sure we start with a clean configuration
        CfgMgr::instance().deleteSubnets4();
        CfgMgr::instance().deleteSubnets6();
        CfgMgr::instance().deleteOptionDefs();
        CfgMgr::instance().deleteActiveIfaces();
    }

    /// @brief generates interface-id option based on provided text
    ///
    /// @param text content of the option to be created
    ///
    /// @return pointer to the option object created
    OptionPtr generateInterfaceId(const string& text) {
        OptionBuffer buffer(text.begin(), text.end());
        return OptionPtr(new Option(Option::V6, D6O_INTERFACE_ID, buffer));
    }

    ~CfgMgrTest() {
        // clean up after the test
        CfgMgr::instance().deleteSubnets4();
        CfgMgr::instance().deleteSubnets6();
        CfgMgr::instance().deleteOptionDefs();
    }

    /// used in client classification (or just empty container for other tests)
    isc::dhcp::ClientClasses classify_;
};

// This test verifies that multiple option definitions can be added
// under different option spaces.
TEST_F(CfgMgrTest, getOptionDefs) {
    CfgMgr& cfg_mgr = CfgMgr::instance();
    // Create a set of option definitions with codes between 100 and 109.
    for (uint16_t code = 100; code < 110; ++code) {
        std::ostringstream option_name;
        // Option name is unique, e.g. option-100, option-101 etc.
        option_name << "option-" << code;
        OptionDefinitionPtr def(new OptionDefinition(option_name.str(), code,
                                                     "uint16"));
        // Add option definition to "isc" option space.
        // Option codes are not duplicated so expect no error
        // when adding them.
        ASSERT_NO_THROW(cfg_mgr.addOptionDef(def, "isc"));
    }

    // Create a set of option definitions with codes between 105 and 114 and
    // add them to the different option space.
    for (uint16_t code = 105; code < 115; ++code) {
        std::ostringstream option_name;
        option_name << "option-" << code;
        OptionDefinitionPtr def(new OptionDefinition(option_name.str(), code,
                                                     "uint16"));
        ASSERT_NO_THROW(cfg_mgr.addOptionDef(def, "abcde"));
    }

    // Sanity check that all 10 option definitions are there.
    OptionDefContainerPtr option_defs1 = cfg_mgr.getOptionDefs("isc");
    ASSERT_TRUE(option_defs1);
    ASSERT_EQ(10, option_defs1->size());

    // Iterate over all option definitions and check that they have
    // valid codes. Also, their order should be the same as they
    // were added (codes 100-109).
    uint16_t code = 100;
    for (OptionDefContainer::const_iterator it = option_defs1->begin();
         it != option_defs1->end(); ++it, ++code) {
        OptionDefinitionPtr def(*it);
        ASSERT_TRUE(def);
        EXPECT_EQ(code, def->getCode());
    }

    // Sanity check that all 10 option definitions are there.
    OptionDefContainerPtr option_defs2 = cfg_mgr.getOptionDefs("abcde");
    ASSERT_TRUE(option_defs2);
    ASSERT_EQ(10, option_defs2->size());

    // Check that the option codes are valid.
    code = 105;
    for (OptionDefContainer::const_iterator it = option_defs2->begin();
         it != option_defs2->end(); ++it, ++code) {
        OptionDefinitionPtr def(*it);
        ASSERT_TRUE(def);
        EXPECT_EQ(code, def->getCode());
    }

    // Let's make one more check that the empty set is returned when
    // invalid option space is used.
    OptionDefContainerPtr option_defs3 = cfg_mgr.getOptionDefs("non-existing");
    ASSERT_TRUE(option_defs3);
    EXPECT_TRUE(option_defs3->empty());
}

// This test verifies that single option definition is correctly
// returned with getOptionDef function.
TEST_F(CfgMgrTest, getOptionDef) {
    CfgMgr& cfg_mgr = CfgMgr::instance();
    // Create a set of option definitions with codes between 100 and 109.
    for (uint16_t code = 100; code < 110; ++code) {
        std::ostringstream option_name;
        // Option name is unique, e.g. option-100, option-101 etc.
        option_name << "option-" << code;
        OptionDefinitionPtr def(new OptionDefinition(option_name.str(), code,
                                                     "uint16"));
        // Add option definition to "isc" option space.
        // Option codes are not duplicated so expect no error
        // when adding them.
        ASSERT_NO_THROW(cfg_mgr.addOptionDef(def, "isc"));
    }

    // Create a set of option definitions with codes between 105 and 114 and
    // add them to the different option space.
    for (uint16_t code = 105; code < 115; ++code) {
        std::ostringstream option_name;
        option_name << "option-other-" << code;
        OptionDefinitionPtr def(new OptionDefinition(option_name.str(), code,
                                                     "uint16"));
        ASSERT_NO_THROW(cfg_mgr.addOptionDef(def, "abcde"));
    }

    // Try to get option definitions one by one using all codes
    // that we expect to be there.
    for (uint16_t code = 100; code < 110; ++code) {
        OptionDefinitionPtr def = cfg_mgr.getOptionDef("isc", code);
        ASSERT_TRUE(def);
        // Check that the option name is in the format of 'option-[code]'.
        // That way we make sure that the options that have the same codes
        // within different option spaces are different.
        std::ostringstream option_name;
        option_name << "option-" << code;
        EXPECT_EQ(option_name.str(), def->getName());
        EXPECT_EQ(code, def->getCode());
    }

    // Check that the option codes are valid.
    for (uint16_t code = 105; code < 115; ++code) {
        OptionDefinitionPtr def = cfg_mgr.getOptionDef("abcde", code);
        ASSERT_TRUE(def);
        // Check that the option name is in the format of 'option-other-[code]'.
        // That way we make sure that the options that have the same codes
        // within different option spaces are different.
        std::ostringstream option_name;
        option_name << "option-other-" << code;
        EXPECT_EQ(option_name.str(), def->getName());

        EXPECT_EQ(code, def->getCode());
    }

    // Check that an option definition can be added to the standard
    // (dhcp4 and dhcp6) option spaces when the option code is not
    // reserved by the standard option.
    OptionDefinitionPtr def6(new OptionDefinition("option-foo", 79, "uint16"));
    EXPECT_NO_THROW(cfg_mgr.addOptionDef(def6, "dhcp6"));

    OptionDefinitionPtr def4(new OptionDefinition("option-foo", 222, "uint16"));
    EXPECT_NO_THROW(cfg_mgr.addOptionDef(def4, "dhcp4"));

    // Try to query the option definition from an non-existing
    // option space and expect NULL pointer.
    OptionDefinitionPtr def = cfg_mgr.getOptionDef("non-existing", 56);
    EXPECT_FALSE(def);

    // Try to get the non-existing option definition from an
    // existing option space.
    EXPECT_FALSE(cfg_mgr.getOptionDef("isc", 56));

}

// This test verifies that it is not allowed to override a definition of the
// standard option which has its definition defined in libdhcp++, but it is
// allowed to create a definition for the standard option which doesn't have
// its definition in libdhcp++.
TEST_F(CfgMgrTest, overrideStdOptionDef) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    OptionDefinitionPtr def;
    // There is a definition for routers option in libdhcp++, so an attempt
    // to add (override) another definition for this option should fail.
    def.reset(new OptionDefinition("routers", DHO_ROUTERS, "uint32"));
    EXPECT_THROW(cfg_mgr.addOptionDef(def, "dhcp4"), isc::BadValue);

    /// @todo There is no definition for the NIS Server Addr option in
    /// libdhcp++. Once it is implemented it should be not allowed to
    /// add a custom definition for it. At the moment, it should be ok
    /// to add a definition for this option (using configuration mechanism)
    /// because we haven't implemented the one in libdhcp++.
    def.reset(new OptionDefinition("nis-server-addr", 65, "uint16"));
    EXPECT_NO_THROW(cfg_mgr.addOptionDef(def, "dhcp4"));

    // It is not allowed to override the definition of the option which
    // has its definition in the libdhcp++.
    def.reset(new OptionDefinition("sntp-servers", D6O_SNTP_SERVERS,
                                   "ipv4-address"));
    EXPECT_THROW(cfg_mgr.addOptionDef(def, "dhcp6"), isc::BadValue);
    // There is no definition for option 59 in libdhcp++ yet, so it should
    // be possible provide a custom definition.
    def.reset(new OptionDefinition("bootfile-url", 59, "uint32"));
    EXPECT_NO_THROW(cfg_mgr.addOptionDef(def, "dhcp6"));

}

// This test verifies that the function that adds new option definition
// throws exceptions when arguments are invalid.
TEST_F(CfgMgrTest, addOptionDefNegative) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    OptionDefinitionPtr def(new OptionDefinition("option-foo", 1000, "uint16"));

    // Try empty option space name.
    ASSERT_THROW(cfg_mgr.addOptionDef(def, ""), isc::BadValue);
    // Try NULL option definition.
    ASSERT_THROW(cfg_mgr.addOptionDef(OptionDefinitionPtr(), "isc"),
                 isc::dhcp::MalformedOptionDefinition);
    // Try adding option definition twice and make sure that it
    // fails on the second attempt.
    ASSERT_NO_THROW(cfg_mgr.addOptionDef(def, "isc"));
    EXPECT_THROW(cfg_mgr.addOptionDef(def, "isc"), DuplicateOptionDefinition);
}

// This test verifies if the configuration manager is able to hold and return
// valid subnets.
TEST_F(CfgMgrTest, subnet4) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    Subnet4Ptr subnet1(new Subnet4(IOAddress("192.0.2.0"), 26, 1, 2, 3));
    Subnet4Ptr subnet2(new Subnet4(IOAddress("192.0.2.64"), 26, 1, 2, 3));
    Subnet4Ptr subnet3(new Subnet4(IOAddress("192.0.2.128"), 26, 1, 2, 3));

    // There shouldn't be any subnet configured at this stage
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.0"), classify_));

    cfg_mgr.addSubnet4(subnet1);

    // Now we have only one subnet, any request will be served from it
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet4(IOAddress("192.0.2.63"),
                  classify_));

    // Now we add more subnets and check that both old and new subnets
    // are accessible.
    cfg_mgr.addSubnet4(subnet2);
    cfg_mgr.addSubnet4(subnet3);

    EXPECT_EQ(subnet3, cfg_mgr.getSubnet4(IOAddress("192.0.2.191"), classify_));
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet4(IOAddress("192.0.2.15"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet4(IOAddress("192.0.2.85"), classify_));

    // Try to find an address that does not belong to any subnet
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.192"), classify_));

    // Check that deletion of the subnets works.
    cfg_mgr.deleteSubnets4();
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.191"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.15"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.85"), classify_));
}

// This test verifies if the configuration manager is able to hold subnets with
// their classifier information and return proper subnets, based on those
// classes.
TEST_F(CfgMgrTest, classifySubnet4) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Let's configure 3 subnets
    Subnet4Ptr subnet1(new Subnet4(IOAddress("192.0.2.0"), 26, 1, 2, 3));
    Subnet4Ptr subnet2(new Subnet4(IOAddress("192.0.2.64"), 26, 1, 2, 3));
    Subnet4Ptr subnet3(new Subnet4(IOAddress("192.0.2.128"), 26, 1, 2, 3));

    cfg_mgr.addSubnet4(subnet1);
    cfg_mgr.addSubnet4(subnet2);
    cfg_mgr.addSubnet4(subnet3);

    // Let's sanity check that we can use that configuration.
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet4(IOAddress("192.0.2.5"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet4(IOAddress("192.0.2.70"), classify_));
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet4(IOAddress("192.0.2.130"), classify_));

    // Client now belongs to bar class.
    classify_.insert("bar");

    // There are no class restrictions defined, so everything should work
    // as before
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet4(IOAddress("192.0.2.5"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet4(IOAddress("192.0.2.70"), classify_));
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet4(IOAddress("192.0.2.130"), classify_));

    // Now let's add client class restrictions.
    subnet1->allowClientClass("foo"); // Serve here only clients from foo class
    subnet2->allowClientClass("bar"); // Serve here only clients from bar class
    subnet3->allowClientClass("baz"); // Serve here only clients from baz class

    // The same check as above should result in client being served only in
    // bar class, i.e. subnet2
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.5"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet4(IOAddress("192.0.2.70"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.130"), classify_));

    // Now let's check that client with wrong class is not supported
    classify_.clear();
    classify_.insert("some_other_class");
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.5"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.70"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.130"), classify_));

    // Finally, let's check that client without any classes is not supported
    classify_.clear();
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.5"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.70"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("192.0.2.130"), classify_));
}

// This test verifies if the configuration manager is able to hold v4 subnets
// with their relay address information and return proper subnets, based on
// those addresses.
TEST_F(CfgMgrTest, subnet4RelayOverride) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Let's configure 3 subnets
    Subnet4Ptr subnet1(new Subnet4(IOAddress("192.0.2.0"), 26, 1, 2, 3));
    Subnet4Ptr subnet2(new Subnet4(IOAddress("192.0.2.64"), 26, 1, 2, 3));
    Subnet4Ptr subnet3(new Subnet4(IOAddress("192.0.2.128"), 26, 1, 2, 3));

    cfg_mgr.addSubnet4(subnet1);
    cfg_mgr.addSubnet4(subnet2);
    cfg_mgr.addSubnet4(subnet3);

    // Check that without relay-info specified, subnets are not selected
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("10.0.0.1"), classify_, true));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("10.0.0.2"), classify_, true));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("10.0.0.3"), classify_, true));

    // Now specify relay info
    subnet1->setRelayInfo(IOAddress("10.0.0.1"));
    subnet2->setRelayInfo(IOAddress("10.0.0.2"));
    subnet3->setRelayInfo(IOAddress("10.0.0.3"));

    // And try again. This time relay-info is there and should match.
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet4(IOAddress("10.0.0.1"), classify_, true));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet4(IOAddress("10.0.0.2"), classify_, true));
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet4(IOAddress("10.0.0.3"), classify_, true));

    // Finally, check that the relay works only if hint provided is relay address
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("10.0.0.1"), classify_, false));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("10.0.0.2"), classify_, false));
    EXPECT_FALSE(cfg_mgr.getSubnet4(IOAddress("10.0.0.3"), classify_, false));
}

// This test verifies if the configuration manager is able to hold v6 subnets
// with their relay address information and return proper subnets, based on
// those addresses.
TEST_F(CfgMgrTest, subnet6RelayOverride) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Let's configure 3 subnets
    Subnet6Ptr subnet1(new Subnet6(IOAddress("2001:db8:1::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("2001:db8:2::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("2001:db8:3::"), 48, 1, 2, 3, 4));

    cfg_mgr.addSubnet6(subnet1);
    cfg_mgr.addSubnet6(subnet2);
    cfg_mgr.addSubnet6(subnet3);

    // Check that without relay-info specified, subnets are not selected
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::1"), classify_, true));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::2"), classify_, true));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::3"), classify_, true));

    // Now specify relay info
    subnet1->setRelayInfo(IOAddress("2001:db8:ff::1"));
    subnet2->setRelayInfo(IOAddress("2001:db8:ff::2"));
    subnet3->setRelayInfo(IOAddress("2001:db8:ff::3"));

    // And try again. This time relay-info is there and should match.
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::1"), classify_, true));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::2"), classify_, true));
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::3"), classify_, true));

    // Finally, check that the relay works only if hint provided is relay address
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::1"), classify_, false));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::2"), classify_, false));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2001:db8:ff::3"), classify_, false));
}


// This test verifies if the configuration manager is able to hold and return
// valid leases
TEST_F(CfgMgrTest, classifySubnet6) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Let's configure 3 subnets
    Subnet6Ptr subnet1(new Subnet6(IOAddress("2000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("3000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("4000::"), 48, 1, 2, 3, 4));

    cfg_mgr.addSubnet6(subnet1);
    cfg_mgr.addSubnet6(subnet2);
    cfg_mgr.addSubnet6(subnet3);

    // Let's sanity check that we can use that configuration.
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6(IOAddress("2000::123"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6(IOAddress("3000::345"), classify_));
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6(IOAddress("4000::567"), classify_));

    // Client now belongs to bar class.
    classify_.insert("bar");

    // There are no class restrictions defined, so everything should work
    // as before
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6(IOAddress("2000::123"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6(IOAddress("3000::345"), classify_));
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6(IOAddress("4000::567"), classify_));

    // Now let's add client class restrictions.
    subnet1->allowClientClass("foo"); // Serve here only clients from foo class
    subnet2->allowClientClass("bar"); // Serve here only clients from bar class
    subnet3->allowClientClass("baz"); // Serve here only clients from baz class

    // The same check as above should result in client being served only in
    // bar class, i.e. subnet2
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2000::123"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6(IOAddress("3000::345"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("4000::567"), classify_));

    // Now let's check that client with wrong class is not supported
    classify_.clear();
    classify_.insert("some_other_class");
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2000::123"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("3000::345"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("4000::567"), classify_));

    // Finally, let's check that client without any classes is not supported
    classify_.clear();
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2000::123"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("3000::345"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("4000::567"), classify_));
}

// This test verifies if the configuration manager is able to hold, select
// and return valid subnets, based on interface names along with client
// classification.
TEST_F(CfgMgrTest, classifySubnet6Interface) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Let's have an odd configuration: 3 shared subnets available on the
    // same direct link.
    Subnet6Ptr subnet1(new Subnet6(IOAddress("2000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("3000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("4000::"), 48, 1, 2, 3, 4));
    subnet1->setIface("foo");
    subnet2->setIface("foo");
    subnet3->setIface("foo");
    cfg_mgr.addSubnet6(subnet1);
    cfg_mgr.addSubnet6(subnet2);
    cfg_mgr.addSubnet6(subnet3);


    // Regular client should get the first subnet, because it meets all
    // criteria (matching interface name, no class restrictions.
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6("foo", classify_));

    // Now let's add class requirements for subnet1
    subnet1->allowClientClass("alpha");

    // Client should now get the subnet2, because he no longer meets
    // requirements for subnet1 (belongs to wrong class)
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6("foo", classify_));

    // Now let's add (not matching) classes to the other two subnets
    subnet2->allowClientClass("beta");
    subnet3->allowClientClass("gamma");

    // No subnets are suitable, so nothing will be selected
    EXPECT_FALSE(cfg_mgr.getSubnet6("foo", classify_));

    // Ok, let's add the client to gamme class, so he'll get a subnet
    classify_.insert("gamma");
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6("foo", classify_));
}

// This test verifies if the configuration manager is able to hold, select
// and return valid subnets, based on interface-id option inserted by relay,
// along with client classification.
TEST_F(CfgMgrTest, classifySubnet6InterfaceId) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Let's have an odd configuration: 3 shared subnets available via the
    // same remote relay with the same interface-id.
    Subnet6Ptr subnet1(new Subnet6(IOAddress("2000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("3000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("4000::"), 48, 1, 2, 3, 4));
    OptionPtr ifaceid = generateInterfaceId("relay1.eth0");
    subnet1->setInterfaceId(ifaceid);
    subnet2->setInterfaceId(ifaceid);
    subnet3->setInterfaceId(ifaceid);
    cfg_mgr.addSubnet6(subnet1);
    cfg_mgr.addSubnet6(subnet2);
    cfg_mgr.addSubnet6(subnet3);

    // Regular client should get the first subnet, because it meets all
    // criteria (matching interface name, no class restrictions.
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6(ifaceid, classify_));

    // Now let's add class requirements for subnet1
    subnet1->allowClientClass("alpha");

    // Client should now get the subnet2, because he no longer meets
    // requirements for subnet1 (belongs to wrong class)
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6(ifaceid, classify_));

    // Now let's add (not matching) classes to the other two subnets
    subnet2->allowClientClass("beta");
    subnet3->allowClientClass("gamma");

    // No subnets are suitable, so nothing will be selected
    EXPECT_FALSE(cfg_mgr.getSubnet6(ifaceid, classify_));

    // Ok, let's add the client to gamme class, so he'll get a subnet
    classify_.insert("gamma");
    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6(ifaceid, classify_));
}

// This test verifies if the configuration manager is able to hold and return
// valid leases
TEST_F(CfgMgrTest, subnet6) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    Subnet6Ptr subnet1(new Subnet6(IOAddress("2000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("3000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("4000::"), 48, 1, 2, 3, 4));

    // There shouldn't be any subnet configured at this stage
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2000::1"), classify_));

    cfg_mgr.addSubnet6(subnet1);

    // Now we have only one subnet, any request will be served from it
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6(IOAddress("2000::1"), classify_));

    // We used to allow getting a sole subnet if there was only one subnet
    // configured. That is no longer true. The code should not return
    // a subnet.
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("fe80::dead:beef"), classify_));

    cfg_mgr.addSubnet6(subnet2);
    cfg_mgr.addSubnet6(subnet3);

    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6(IOAddress("4000::123"), classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6(IOAddress("3000::dead:beef"),
                  classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("5000::1"), classify_));

    // Check that deletion of the subnets works.
    cfg_mgr.deleteSubnets6();
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("2000::123"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("3000::123"), classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("4000::123"), classify_));
}

// This test verifies if the configuration manager is able to hold, select
// and return valid subnets, based on interface names.
TEST_F(CfgMgrTest, subnet6Interface) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    Subnet6Ptr subnet1(new Subnet6(IOAddress("2000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("3000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("4000::"), 48, 1, 2, 3, 4));
    subnet1->setIface("foo");
    subnet2->setIface("bar");
    subnet3->setIface("foobar");

    // There shouldn't be any subnet configured at this stage
    EXPECT_FALSE(cfg_mgr.getSubnet6("foo", classify_));

    cfg_mgr.addSubnet6(subnet1);

    // Now we have only one subnet, any request will be served from it
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6("foo", classify_));

    // Check that the interface name is checked even when there is
    // only one subnet defined.
    EXPECT_FALSE(cfg_mgr.getSubnet6("bar", classify_));

    // We used to allow getting a sole subnet if there was only one subnet
    // configured. That is no longer true. The code should not return
    // a subnet.
    EXPECT_FALSE(cfg_mgr.getSubnet6(IOAddress("fe80::dead:beef"), classify_));

    cfg_mgr.addSubnet6(subnet2);
    cfg_mgr.addSubnet6(subnet3);

    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6("foobar", classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6("bar", classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6("xyzzy", classify_)); // no such interface

    // Check that deletion of the subnets works.
    cfg_mgr.deleteSubnets6();
    EXPECT_FALSE(cfg_mgr.getSubnet6("foo", classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6("bar", classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6("foobar", classify_));
}

// This test verifies if the configuration manager is able to hold, select
// and return valid leases, based on interface-id option values
TEST_F(CfgMgrTest, subnet6InterfaceId) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    Subnet6Ptr subnet1(new Subnet6(IOAddress("2000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("3000::"), 48, 1, 2, 3, 4));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("4000::"), 48, 1, 2, 3, 4));

    // interface-id options used in subnets 1,2, and 3
    OptionPtr ifaceid1 = generateInterfaceId("relay1.eth0");
    OptionPtr ifaceid2 = generateInterfaceId("VL32");
    // That's a strange interface-id, but this is a real life example
    OptionPtr ifaceid3 = generateInterfaceId("ISAM144|299|ipv6|nt:vp:1:110");

    // bogus interface-id
    OptionPtr ifaceid_bogus = generateInterfaceId("non-existent");

    subnet1->setInterfaceId(ifaceid1);
    subnet2->setInterfaceId(ifaceid2);
    subnet3->setInterfaceId(ifaceid3);

    // There shouldn't be any subnet configured at this stage
    EXPECT_FALSE(cfg_mgr.getSubnet6(ifaceid1, classify_));

    cfg_mgr.addSubnet6(subnet1);

    // If we have only a single subnet and the request came from a local
    // address, let's use that subnet
    EXPECT_EQ(subnet1, cfg_mgr.getSubnet6(ifaceid1, classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(ifaceid2, classify_));

    cfg_mgr.addSubnet6(subnet2);
    cfg_mgr.addSubnet6(subnet3);

    EXPECT_EQ(subnet3, cfg_mgr.getSubnet6(ifaceid3, classify_));
    EXPECT_EQ(subnet2, cfg_mgr.getSubnet6(ifaceid2, classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(ifaceid_bogus, classify_));

    // Check that deletion of the subnets works.
    cfg_mgr.deleteSubnets6();
    EXPECT_FALSE(cfg_mgr.getSubnet6(ifaceid1, classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(ifaceid2, classify_));
    EXPECT_FALSE(cfg_mgr.getSubnet6(ifaceid3, classify_));
}


// This test verifies that new DHCPv4 option spaces can be added to
// the configuration manager and that duplicated option space is
// rejected.
TEST_F(CfgMgrTest, optionSpace4) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Create some option spaces.
    OptionSpacePtr space1(new OptionSpace("isc", false));
    OptionSpacePtr space2(new OptionSpace("xyz", true));

    // Add option spaces with different names and expect they
    // are accepted.
    ASSERT_NO_THROW(cfg_mgr.addOptionSpace4(space1));
    ASSERT_NO_THROW(cfg_mgr.addOptionSpace4(space2));

    // Validate that the option spaces have been added correctly.
    const OptionSpaceCollection& spaces = cfg_mgr.getOptionSpaces4();

    ASSERT_EQ(2, spaces.size());
    EXPECT_FALSE(spaces.find("isc") == spaces.end());
    EXPECT_FALSE(spaces.find("xyz") == spaces.end());

    // Create another option space with the name that duplicates
    // the existing option space.
    OptionSpacePtr space3(new OptionSpace("isc", true));
    // Expect that the duplicate option space is rejected.
    ASSERT_THROW(
        cfg_mgr.addOptionSpace4(space3), isc::dhcp::InvalidOptionSpace
    );

    /// @todo decode if a duplicate vendor space is allowed.
}

// This test verifies that new DHCPv6 option spaces can be added to
// the configuration manager and that duplicated option space is
// rejected.
TEST_F(CfgMgrTest, optionSpace6) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Create some option spaces.
    OptionSpacePtr space1(new OptionSpace("isc", false));
    OptionSpacePtr space2(new OptionSpace("xyz", true));

    // Add option spaces with different names and expect they
    // are accepted.
    ASSERT_NO_THROW(cfg_mgr.addOptionSpace6(space1));
    ASSERT_NO_THROW(cfg_mgr.addOptionSpace6(space2));

    // Validate that the option spaces have been added correctly.
    const OptionSpaceCollection& spaces = cfg_mgr.getOptionSpaces6();

    ASSERT_EQ(2, spaces.size());
    EXPECT_FALSE(spaces.find("isc") == spaces.end());
    EXPECT_FALSE(spaces.find("xyz") == spaces.end());

    // Create another option space with the name that duplicates
    // the existing option space.
    OptionSpacePtr space3(new OptionSpace("isc", true));
    // Expect that the duplicate option space is rejected.
    ASSERT_THROW(
        cfg_mgr.addOptionSpace6(space3), isc::dhcp::InvalidOptionSpace
    );

    /// @todo decide if a duplicate vendor space is allowed.
}

// This test verifies that it is possible to specify interfaces that server
// should listen on.
TEST_F(CfgMgrTest, addActiveIface) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    EXPECT_NO_THROW(cfg_mgr.addActiveIface("eth0"));
    EXPECT_NO_THROW(cfg_mgr.addActiveIface("eth1"));

    EXPECT_TRUE(cfg_mgr.isActiveIface("eth0"));
    EXPECT_TRUE(cfg_mgr.isActiveIface("eth1"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth2"));

    EXPECT_NO_THROW(cfg_mgr.deleteActiveIfaces());

    EXPECT_FALSE(cfg_mgr.isActiveIface("eth0"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth1"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth2"));
}


// This test verifies that it is possible to specify interfaces that server
// should listen on.
TEST_F(CfgMgrTest, addUnicastAddresses) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    EXPECT_NO_THROW(cfg_mgr.addActiveIface("eth1/2001:db8::1"));
    EXPECT_NO_THROW(cfg_mgr.addActiveIface("eth2/2001:db8::2"));
    EXPECT_NO_THROW(cfg_mgr.addActiveIface("eth3"));

    EXPECT_TRUE(cfg_mgr.isActiveIface("eth1"));
    EXPECT_TRUE(cfg_mgr.isActiveIface("eth2"));
    EXPECT_TRUE(cfg_mgr.isActiveIface("eth3"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth4"));

    ASSERT_TRUE(cfg_mgr.getUnicast("eth1"));
    EXPECT_EQ("2001:db8::1", cfg_mgr.getUnicast("eth1")->toText());
    EXPECT_EQ("2001:db8::2", cfg_mgr.getUnicast("eth2")->toText());
    EXPECT_FALSE(cfg_mgr.getUnicast("eth3"));
    EXPECT_FALSE(cfg_mgr.getUnicast("eth4"));

    EXPECT_NO_THROW(cfg_mgr.deleteActiveIfaces());

    EXPECT_FALSE(cfg_mgr.isActiveIface("eth1"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth2"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth3"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth4"));

    ASSERT_FALSE(cfg_mgr.getUnicast("eth1"));
    ASSERT_FALSE(cfg_mgr.getUnicast("eth2"));
    EXPECT_FALSE(cfg_mgr.getUnicast("eth3"));
    EXPECT_FALSE(cfg_mgr.getUnicast("eth4"));
}


// This test verifies that it is possible to set the flag which configures the
// server to listen on all interfaces.
TEST_F(CfgMgrTest, activateAllIfaces) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    cfg_mgr.addActiveIface("eth0");
    cfg_mgr.addActiveIface("eth1");

    ASSERT_TRUE(cfg_mgr.isActiveIface("eth0"));
    ASSERT_TRUE(cfg_mgr.isActiveIface("eth1"));
    ASSERT_FALSE(cfg_mgr.isActiveIface("eth2"));

    cfg_mgr.activateAllIfaces();

    EXPECT_TRUE(cfg_mgr.isActiveIface("eth0"));
    EXPECT_TRUE(cfg_mgr.isActiveIface("eth1"));
    EXPECT_TRUE(cfg_mgr.isActiveIface("eth2"));

    cfg_mgr.deleteActiveIfaces();

    EXPECT_FALSE(cfg_mgr.isActiveIface("eth0"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth1"));
    EXPECT_FALSE(cfg_mgr.isActiveIface("eth2"));
}

// This test verifies that RFC6842 (echo client-id) compatibility may be
// configured.
TEST_F(CfgMgrTest, echoClientId) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    // Check that the default is true
    EXPECT_TRUE(cfg_mgr.echoClientId());

    // Check that it can be modified to false
    cfg_mgr.echoClientId(false);
    EXPECT_FALSE(cfg_mgr.echoClientId());

    // Check that the default value can be restored
    cfg_mgr.echoClientId(true);
    EXPECT_TRUE(cfg_mgr.echoClientId());
}

// This test checks the D2ClientMgr wrapper methods.
TEST_F(CfgMgrTest, d2ClientConfig) {
    // After CfgMgr construction, D2ClientMgr member should be initialized
    // with a D2 configuration that is disabled.
    // Verify we can Fetch the mgr.
    D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr();
    EXPECT_FALSE(d2_mgr.ddnsEnabled());

    // Make sure the convenience method fetches the config correctly.
    D2ClientConfigPtr original_config = CfgMgr::instance().getD2ClientConfig();
    ASSERT_TRUE(original_config);
    EXPECT_FALSE(original_config->getEnableUpdates());

    // Verify that we cannot set the configuration to an empty pointer.
    D2ClientConfigPtr new_cfg;
    ASSERT_THROW(CfgMgr::instance().setD2ClientConfig(new_cfg), D2ClientError);

    // Create a new, enabled configuration.
    ASSERT_NO_THROW(new_cfg.reset(new D2ClientConfig(true,
                                  isc::asiolink::IOAddress("127.0.0.1"), 477,
                                  dhcp_ddns::NCR_UDP, dhcp_ddns::FMT_JSON,
                                  true, true, true, true,
                                  "pre-fix", "suf-fix")));

    // Verify that we can assign a new, non-empty configuration.
    ASSERT_NO_THROW(CfgMgr::instance().setD2ClientConfig(new_cfg));

    // Verify that we can fetch the newly assigned configuration.
    D2ClientConfigPtr updated_config = CfgMgr::instance().getD2ClientConfig();
    ASSERT_TRUE(updated_config);
    EXPECT_TRUE(updated_config->getEnableUpdates());

    // Make sure convenience method agrees with updated configuration.
    EXPECT_TRUE(CfgMgr::instance().ddnsEnabled());

    // Make sure the configuration we fetched is the one we assigned,
    // and not the original configuration.
    EXPECT_EQ(*new_cfg, *updated_config);
    EXPECT_NE(*original_config, *updated_config);
}

// This test verfies that CfgMgr correctly determines that the address of the
// interface belongs to existing IPv4 subnet.
TEST_F(CfgMgrTest, getSubnet4ForInterface) {
    IfaceMgrTestConfig config(true);

    // Initially, there are no subnets configured, so none of the IPv4
    // addresses assigned to eth0 and eth1 can match with any subnet.
    EXPECT_FALSE(CfgMgr::instance().getSubnet4("eth0", classify_));
    EXPECT_FALSE(CfgMgr::instance().getSubnet4("eth1", classify_));

    // Configure first subnet which address on eth0 corresponds to.
    Subnet4Ptr subnet1(new Subnet4(IOAddress("10.0.0.1"), 24, 1, 2, 3));
    CfgMgr::instance().addSubnet4(subnet1);

    // The address on eth0 should match the existing subnet.
    Subnet4Ptr subnet1_ret;
    subnet1_ret = CfgMgr::instance().getSubnet4("eth0", classify_);
    ASSERT_TRUE(subnet1_ret);
    EXPECT_EQ(subnet1->get().first, subnet1_ret->get().first);
    // There should still be no match for eth1.
    EXPECT_FALSE(CfgMgr::instance().getSubnet4("eth1", classify_));

    // Configure a second subnet.
    Subnet4Ptr subnet2(new Subnet4(IOAddress("192.0.2.1"), 24, 1, 2, 3));
    CfgMgr::instance().addSubnet4(subnet2);

    // There should be match between eth0 and subnet1 and between eth1 and
    // subnet 2.
    subnet1_ret = CfgMgr::instance().getSubnet4("eth0", classify_);
    ASSERT_TRUE(subnet1_ret);
    EXPECT_EQ(subnet1->get().first, subnet1_ret->get().first);
    Subnet4Ptr subnet2_ret = CfgMgr::instance().getSubnet4("eth1", classify_);
    ASSERT_TRUE(subnet2_ret);
    EXPECT_EQ(subnet2->get().first, subnet2_ret->get().first);

    // This function throws an exception if the name of the interface is wrong.
    EXPECT_THROW(CfgMgr::instance().getSubnet4("bogus-interface", classify_),
                 isc::BadValue);

}

// Checks that detection of duplicated subnet IDs works as expected. It should
// not be possible to add two IPv4 subnets holding the same ID to the config
// manager.
TEST_F(CfgMgrTest, subnet4Duplication) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    Subnet4Ptr subnet1(new Subnet4(IOAddress("192.0.2.0"), 26, 1, 2, 3, 123));
    Subnet4Ptr subnet2(new Subnet4(IOAddress("192.0.2.64"), 26, 1, 2, 3, 124));
    Subnet4Ptr subnet3(new Subnet4(IOAddress("192.0.2.128"), 26, 1, 2, 3, 123));

    ASSERT_NO_THROW(cfg_mgr.addSubnet4(subnet1));
    EXPECT_NO_THROW(cfg_mgr.addSubnet4(subnet2));
    // Subnet 3 has the same ID as subnet 1. It shouldn't be able to add it.
    EXPECT_THROW(cfg_mgr.addSubnet4(subnet3), isc::dhcp::DuplicateSubnetID);
}

// Checks that detection of duplicated subnet IDs works as expected. It should
// not be possible to add two IPv6 subnets holding the same ID to the config
// manager.
TEST_F(CfgMgrTest, subnet6Duplication) {
    CfgMgr& cfg_mgr = CfgMgr::instance();

    Subnet6Ptr subnet1(new Subnet6(IOAddress("2001:db8:1::"), 64, 1, 2, 3,
                                   4, 123));
    Subnet6Ptr subnet2(new Subnet6(IOAddress("2001:db8:2::"), 64, 1, 2, 3,
                                   4, 124));
    Subnet6Ptr subnet3(new Subnet6(IOAddress("2001:db8:3::"), 64, 1, 2, 3,
                                   4, 123));

    ASSERT_NO_THROW(cfg_mgr.addSubnet6(subnet1));
    EXPECT_NO_THROW(cfg_mgr.addSubnet6(subnet2));
    // Subnet 3 has the same ID as subnet 1. It shouldn't be able to add it.
    EXPECT_THROW(cfg_mgr.addSubnet6(subnet3), isc::dhcp::DuplicateSubnetID);
}


/// @todo Add unit-tests for testing:
/// - addActiveIface() with invalid interface name
/// - addActiveIface() with the same interface twice
/// - addActiveIface() with a bogus address
///
/// This is somewhat tricky. Care should be taken here, because it is rather
/// difficult to decide if interface name is valid or not. Some servers, e.g.
/// dibbler, allow to specify interface names that are not currently present in
/// the system. The server accepts them, but upon discovering that they are
/// yet available (for different definitions of not being available), adds
/// the to to-be-activated list.
///
/// Cases covered by dibbler are:
/// - missing interface (e.g. PPP connection that is not established yet)
/// - downed interface (no link local address, no way to open sockets)
/// - up, but not running interface (wifi up, but not associated)
/// - tentative addresses (interface up and running, but DAD procedure is
///   still in progress)
/// - weird interfaces without link-local addresses (don't ask, 6rd tunnels
///   look weird to me as well)

// No specific tests for getSubnet6. That method (2 overloaded versions) is tested
// in Dhcpv6SrvTest.selectSubnetAddr and Dhcpv6SrvTest.selectSubnetIface
// (see src/bin/dhcp6/tests/dhcp6_srv_unittest.cc)

} // end of anonymous namespace