config_parser_unittest.cc

// Copyright (C) 2012-2017 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 <arpa/inet.h>
#include <gtest/gtest.h>

#include <cc/command_interpreter.h>
#include <config/module_spec.h>
#include <dhcp4/dhcp4_srv.h>
#include <dhcp4/json_config_parser.h>
#include <dhcp/option4_addrlst.h>
#include <dhcp/option_custom.h>
#include <dhcp/option_int.h>
#include <dhcp/docsis3_option_defs.h>
#include <dhcp/classify.h>
#include <dhcp/tests/iface_mgr_test_config.h>
#include <dhcpsrv/subnet.h>
#include <dhcpsrv/cfgmgr.h>
#include <dhcpsrv/cfg_expiration.h>
#include <dhcpsrv/cfg_hosts.h>
#include <dhcpsrv/cfg_subnets4.h>
#include <dhcpsrv/testutils/config_result_check.h>
#include <hooks/hooks_manager.h>

#include "marker_file.h"
#include "test_libraries.h"
#include "test_data_files_config.h"
#include "dhcp4_test_utils.h"

#include <boost/foreach.hpp>
#include <boost/scoped_ptr.hpp>

#include <iostream>
#include <fstream>
#include <sstream>
#include <limits.h>

using namespace isc;
using namespace isc::asiolink;
using namespace isc::config;
using namespace isc::data;
using namespace isc::dhcp;
using namespace isc::dhcp::test;
using namespace isc::hooks;
using namespace std;

namespace {
const char* PARSER_CONFIGS[] = {
    // CONFIGURATION 0: one subnet with one pool, no user contexts
    "{"
    "    \"interfaces-config\": {"
    "        \"interfaces\": [\"*\" ]"
    "    },"
    "    \"valid-lifetime\": 4000,"
    "    \"rebind-timer\": 2000,"
    "    \"renew-timer\": 1000,"
    "    \"subnet4\": [ {"
    "        \"pools\": [ "
    "            { \"pool\":  \"192.0.2.0/28\" }"
    "        ],"
    "        \"subnet\": \"192.0.2.0/24\""
    "     } ]"
    "}",

    // Configuration 1: one pool with empty user context
    "{"
    "    \"interfaces-config\": {"
    "        \"interfaces\": [\"*\" ]"
    "    },"
    "    \"valid-lifetime\": 4000,"
    "    \"rebind-timer\": 2000,"
    "    \"renew-timer\": 1000,"
    "    \"subnet4\": [ {"
    "        \"pools\": [ "
    "            { \"pool\":  \"192.0.2.0/28\","
    "                \"user-context\": {"
    "                }"
    "            }"
    "        ],"
    "        \"subnet\": \"192.0.2.0/24\""
    "     } ]"
    "}",

    // Configuration 2: one pool with user context containing lw4over6 parameters
    "{"
    "    \"interfaces-config\": {"
    "        \"interfaces\": [\"*\" ]"
    "    },"
    "    \"valid-lifetime\": 4000,"
    "    \"rebind-timer\": 2000,"
    "    \"renew-timer\": 1000,"
    "    \"subnet4\": [ {"
    "        \"pools\": [ "
    "            { \"pool\":  \"192.0.2.0/28\","
    "                \"user-context\": {"
    "                    \"integer-param\": 42,"
    "                    \"string-param\": \"Sagittarius\","
    "                    \"bool-param\": true"
    "                }"
    "            }"
    "        ],"
    "        \"subnet\": \"192.0.2.0/24\""
    "     } ]"
    "}",

    // Configuration 3: one min-max pool with user context containing lw4over6 parameters
    "{"
    "    \"interfaces-config\": {"
    "        \"interfaces\": [\"*\" ]"
    "    },"
    "    \"valid-lifetime\": 4000,"
    "    \"rebind-timer\": 2000,"
    "    \"renew-timer\": 1000,"
    "    \"subnet4\": [ {"
    "        \"pools\": [ "
    "            { \"pool\":  \"192.0.2.0 - 192.0.2.15\","
    "                \"user-context\": {"
    "                    \"integer-param\": 42,"
    "                    \"string-param\": \"Sagittarius\","
    "                    \"bool-param\": true"
    "                }"
    "            }"
    "        ],"
    "        \"subnet\": \"192.0.2.0/24\""
    "     } ]"
    "}"
};

/// @brief Prepends the given name with the DHCP4 source directory
///
/// @param name file name of the desired file
/// @return string containing the absolute path of the file in the DHCP source
/// directory.
std::string specfile(const std::string& name) {
    return (std::string(DHCP4_SRC_DIR) + "/" + name);
}

/// @brief Tests that the spec file is valid.
/// Verifies that the Kea DHCPv4 configuration specification file is valid.
TEST(Dhcp4SpecTest, basicSpec) {
    (isc::config::moduleSpecFromFile(specfile("dhcp4.spec")));
    ASSERT_NO_THROW(isc::config::moduleSpecFromFile(specfile("dhcp4.spec")));
}

class Dhcp4ParserTest : public ::testing::Test {
protected:
    // Check that no hooks libraries are loaded.  This is a pre-condition for
    // a number of tests, so is checked in one place.  As this uses an
    // ASSERT call - and it is not clear from the documentation that Gtest
    // predicates can be used in a constructor - the check is placed in SetUp.
    virtual void SetUp() {
        std::vector<std::string> libraries = HooksManager::getLibraryNames();
        ASSERT_TRUE(libraries.empty());
    }

public:
    Dhcp4ParserTest()
    : rcode_(-1) {
        // Open port 0 means to not do anything at all. We don't want to
        // deal with sockets here, just check if configuration handling
        // is sane.
        srv_.reset(new Dhcpv4Srv(0));
        // Create fresh context.
        resetConfiguration();
    }

public:

    // Checks if the result of DHCP server configuration has
    // expected code (0 for success, other for failures).
    // Also stores result in rcode_ and comment_.
    void checkResult(ConstElementPtr status, int expected_code) {
        ASSERT_TRUE(status);
        comment_ = parseAnswer(rcode_, status);
        EXPECT_EQ(expected_code, rcode_);
    }

    ~Dhcp4ParserTest() {
        resetConfiguration();

        // ... and delete the hooks library marker files if present
        static_cast<void>(remove(LOAD_MARKER_FILE));
        static_cast<void>(remove(UNLOAD_MARKER_FILE));
    };

    /// @brief Returns an interface configuration used by the most of the
    /// unit tests.
    std::string genIfaceConfig() const {
        return ("\"interfaces-config\": {"
                "  \"interfaces\": [ \"*\" ]"
                "}");
    }

    /// @brief Create the simple configuration with single option.
    ///
    /// This function allows to set one of the parameters that configure
    /// option value. These parameters are: "name", "code", "data",
    /// "csv-format" and "space".
    ///
    /// @param param_value string holding option parameter value to be
    /// injected into the configuration string.
    /// @param parameter name of the parameter to be configured with
    /// param value.
    /// @return configuration string containing custom values of parameters
    /// describing an option.
    std::string createConfigWithOption(const std::string& param_value,
                                       const std::string& parameter) {
        std::map<std::string, std::string> params;
        if (parameter == "name") {
            params["name"] = param_value;
            params["space"] = DHCP4_OPTION_SPACE;
            params["code"] = "56";
            params["data"] = "ABCDEF0105";
            params["csv-format"] = "false";
        } else if (parameter == "space") {
            params["name"] = "dhcp-message";
            params["space"] = param_value;
            params["code"] = "56";
            params["data"] = "ABCDEF0105";
            params["csv-format"] = "false";
        } else if (parameter == "code") {
            params["name"] = "dhcp-message";
            params["space"] = DHCP4_OPTION_SPACE;
            params["code"] = param_value;
            params["data"] = "ABCDEF0105";
            params["csv-format"] = "false";
        } else if (parameter == "data") {
            params["name"] = "dhcp-message";
            params["space"] = DHCP4_OPTION_SPACE;
            params["code"] = "56";
            params["data"] = param_value;
            params["csv-format"] = "false";
        } else if (parameter == "csv-format") {
            params["name"] = "dhcp-message";
            params["space"] = DHCP4_OPTION_SPACE;
            params["code"] = "56";
            params["data"] = "ABCDEF0105";
            params["csv-format"] = param_value;
        }
        return (createConfigWithOption(params));
    }

    /// @brief Create simple configuration with single option.
    ///
    /// This function creates a configuration for a single option with
    /// custom values for all parameters that describe the option.
    ///
    /// @params params map holding parameters and their values.
    /// @return configuration string containing custom values of parameters
    /// describing an option.
    std::string createConfigWithOption(const std::map<std::string, std::string>& params) {
        std::ostringstream stream;
        stream << "{ " << genIfaceConfig() << "," <<
            "\"rebind-timer\": 2000, "
            "\"renew-timer\": 1000, "
            "\"subnet4\": [ { "
            "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
            "    \"subnet\": \"192.0.2.0/24\", "
            "    \"option-data\": [ {";
        bool first = true;
        typedef std::pair<std::string, std::string> ParamPair;
        BOOST_FOREACH(ParamPair param, params) {
            if (!first) {
                stream << ", ";
            } else {
                // cppcheck-suppress unreadVariable
                first = false;
            }
            if (param.first == "name") {
                stream << "\"name\": \"" << param.second << "\"";
            } else if (param.first == "space") {
                stream << "\"space\": \"" << param.second << "\"";
            } else if (param.first == "code") {
                stream << "\"code\": " << param.second << "";
            } else if (param.first == "data") {
                stream << "\"data\": \"" << param.second << "\"";
            } else if (param.first == "csv-format") {
                stream << "\"csv-format\": " << param.second;
            }
        }
        stream <<
            "        } ]"
            " } ],"
            "\"valid-lifetime\": 4000 }";
        return (stream.str());
    }

    /// @brief Returns an option from the subnet.
    ///
    /// This function returns an option from a subnet to which the
    /// specified subnet address belongs. The option is identified
    /// by its code.
    ///
    /// @param subnet_address Address which belongs to the subnet from
    /// which the option is to be returned.
    /// @param option_code Code of the option to be returned.
    /// @param expected_options_count Expected number of options in
    /// the particular subnet.
    ///
    /// @return Descriptor of the option. If the descriptor holds a
    /// NULL option pointer, it means that there was no such option
    /// in the subnet.
    OptionDescriptor
    getOptionFromSubnet(const IOAddress& subnet_address,
                        const uint16_t option_code,
                        const uint16_t expected_options_count = 1) {
        Subnet4Ptr subnet = CfgMgr::instance().getStagingCfg()->
            getCfgSubnets4()->selectSubnet(subnet_address);
        if (!subnet) {
            /// @todo replace toText() with the use of operator <<.
            ADD_FAILURE() << "A subnet for the specified address "
                          << subnet_address.toText()
                          << "does not exist in Config Manager";
        }
        OptionContainerPtr options =
            subnet->getCfgOption()->getAll(DHCP4_OPTION_SPACE);
        if (expected_options_count != options->size()) {
            ADD_FAILURE() << "The number of options in the subnet '"
                          << subnet_address.toText() << "' is different "
                " than expected number of options '"
                          << expected_options_count << "'";
        }

        // Get the search index. Index #1 is to search using option code.
        const OptionContainerTypeIndex& idx = options->get<1>();

        // Get the options for specified index. Expecting one option to be
        // returned but in theory we may have multiple options with the same
        // code so we get the range.
        std::pair<OptionContainerTypeIndex::const_iterator,
                  OptionContainerTypeIndex::const_iterator> range =
            idx.equal_range(option_code);
        if (std::distance(range.first, range.second) > 1) {
            ADD_FAILURE() << "There is more than one option having the"
                " option code '" << option_code << "' in a subnet '"
                          << subnet_address.toText() << "'. Expected "
                " at most one option";
        } else if (std::distance(range.first, range.second) == 0) {
            return (OptionDescriptor(OptionPtr(), false));
        }

        return (*range.first);
    }

    /// @brief Test invalid option parameter value.
    ///
    /// This test function constructs the simple configuration
    /// string and injects invalid option configuration into it.
    /// It expects that parser will fail with provided option code.
    ///
    /// @param param_value string holding invalid option parameter value
    /// to be injected into configuration string.
    /// @param parameter name of the parameter to be configured with
    /// param_value (can be any of "name", "code", "data")
    void testInvalidOptionParam(const std::string& param_value,
                                const std::string& parameter) {
        ConstElementPtr x;
        std::string config = createConfigWithOption(param_value, parameter);
        ConstElementPtr json = parseDHCP4(config);
        EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
        checkResult(x, 1);
        EXPECT_TRUE(errorContainsPosition(x, "<string>"));
    }

    /// @brief Test invalid option parameter value.
    ///
    /// This test function constructs the simple configuration
    /// string and injects invalid option configuration into it.
    /// It expects that parser will fail with provided option code.
    ///
    /// @param params Map of parameters defining an option.
    void
    testInvalidOptionParam(const std::map<std::string, std::string>& params) {
        ConstElementPtr x;
        std::string config = createConfigWithOption(params);
        ConstElementPtr json = parseDHCP4(config);
        EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
        checkResult(x, 1);
        EXPECT_TRUE(errorContainsPosition(x, "<string>"));
    }

    /// @brief Test option against given code and data.
    ///
    /// @param option_desc option descriptor that carries the option to
    /// be tested.
    /// @param expected_code expected code of the option.
    /// @param expected_data expected data in the option.
    /// @param expected_data_len length of the reference data.
    /// @param extra_data if true extra data is allowed in an option
    /// after tested data.
    void testOption(const OptionDescriptor& option_desc,
                    uint16_t expected_code, const uint8_t* expected_data,
                    size_t expected_data_len,
                    bool extra_data = false) {
        // Check if option descriptor contains valid option pointer.
        ASSERT_TRUE(option_desc.option_);
        // Verify option type.
        EXPECT_EQ(expected_code, option_desc.option_->getType());
        // We may have many different option types being created. Some of them
        // have dedicated classes derived from Option class. In such case if
        // we want to verify the option contents against expected_data we have
        // to prepare raw buffer with the contents of the option. The easiest
        // way is to call pack() which will prepare on-wire data.
        util::OutputBuffer buf(option_desc.option_->getData().size());
        option_desc.option_->pack(buf);
        if (extra_data) {
            // The length of the buffer must be at least equal to size of the
            // reference data but it can sometimes be greater than that. This is
            // because some options carry suboptions that increase the overall
            // length.
            ASSERT_GE(buf.getLength() - option_desc.option_->getHeaderLen(),
                      expected_data_len);
        } else {
            ASSERT_EQ(buf.getLength() - option_desc.option_->getHeaderLen(),
                      expected_data_len);
        }
        // Verify that the data is correct. Do not verify suboptions and a header.
        const uint8_t* data = static_cast<const uint8_t*>(buf.getData());
        EXPECT_EQ(0, memcmp(expected_data, data + option_desc.option_->getHeaderLen(),
                            expected_data_len));
    }

    /// @brief Test option configuration.
    ///
    /// This function creates a configuration for a specified option using
    /// a map of parameters specified as the argument. The map holds
    /// name/value pairs which identifies option's configuration parameters:
    /// - name
    /// - space
    /// - code
    /// - data
    /// - csv-format.
    /// This function applies a new server configuration and checks that the
    /// option being configured is inserted into CfgMgr. The raw contents of
    /// this option are compared with the binary data specified as expected
    /// data passed to this function.
    ///
    /// @param params Map of parameters defining an option.
    /// @param option_code Option code.
    /// @param expected_data Array containing binary data expected to be stored
    /// in the configured option.
    /// @param expected_data_len Length of the array holding reference data.
    void testConfiguration(const std::map<std::string, std::string>& params,
                           const uint16_t option_code,
                           const uint8_t* expected_data,
                           const size_t expected_data_len) {
        std::string config = createConfigWithOption(params);
        ASSERT_TRUE(executeConfiguration(config, "parse option configuration"));
        // The subnet should now hold one option with the specified option code.
        OptionDescriptor desc =
            getOptionFromSubnet(IOAddress("192.0.2.24"), option_code);
        ASSERT_TRUE(desc.option_);
        testOption(desc, option_code, expected_data, expected_data_len);
    }

    /// @brief Parse and Execute configuration
    ///
    /// Parses a configuration and executes a configuration of the server.
    /// If the operation fails, the current test will register a failure.
    ///
    /// @param config Configuration to parse
    /// @param operation Operation being performed.  In the case of an error,
    ///        the error text will include the string "unable to <operation>.".
    ///
    /// @return true if the configuration succeeded, false if not.  In the
    ///         latter case, a failure will have been added to the current test.
    bool
    executeConfiguration(const std::string& config, const char* operation) {
        CfgMgr::instance().clear();
        ConstElementPtr json;
        ConstElementPtr status;
        try {
            json = parseJSON(config);
            status = configureDhcp4Server(*srv_, json);
        } catch (const std::exception& ex) {
            ADD_FAILURE() << "Unable to " << operation << ". "
                   << "The following configuration was used: " << std::endl
                   << config << std::endl
                   << " and the following error message was returned:"
                   << ex.what() << std::endl;
            return (false);
        }

        // The status object must not be NULL
        if (!status) {
            ADD_FAILURE() << "Unable to " << operation << ". "
                   << "The configuration function returned a null pointer.";
            return (false);
        }

        // Store the answer if we need it.

        // Returned value should be 0 (configuration success)
        comment_ = parseAnswer(rcode_, status);
        if (rcode_ != 0) {
            string reason = "";
            if (comment_) {
                reason = string(" (") + comment_->stringValue() + string(")");
            }
            ADD_FAILURE() << "Unable to " << operation << ". "
                   << "The configuration function returned error code "
                   << rcode_ << reason;
            return (false);
        }

        return (true);
    }

    /// @brief Reset configuration database.
    ///
    /// This function resets configuration data base by
    /// removing all subnets and option-data. Reset must
    /// be performed after each test to make sure that
    /// contents of the database do not affect result of
    /// subsequent tests.
    void resetConfiguration() {
        string config = "{ " + genIfaceConfig() + "," +
            "\"hooks-libraries\": [ ], "
            "\"valid-lifetime\": 4000, "
            "\"subnet4\": [ ], "
            "\"dhcp-ddns\": { \"enable-updates\" : false }, "
            "\"option-def\": [ ], "
            "\"option-data\": [ ] }";
        static_cast<void>(executeConfiguration(config,
                                               "reset configuration database"));
        CfgMgr::instance().clear();
    }

    /// @brief Retrieve an option associated with a host.
    ///
    /// The option is retrieved from the "dhcp4" option space.
    ///
    /// @param host Reference to a host for which an option should be retrieved.
    /// @param option_code Option code.
    /// @tparam ReturnType Type of the pointer object returned.
    ///
    /// @return Pointer to an option or NULL pointer if not found.
    template<typename ReturnType>
    ReturnType
    retrieveOption(const Host& host, const uint16_t option_code) const {
        return (retrieveOption<ReturnType>(host, DHCP4_OPTION_SPACE, option_code));
    }

    /// @brief Retrieve an option associated with a host.
    ///
    /// @param host Reference to a host for which an option should be retrieved.
    /// @param space Option space from which option should be retrieved.
    /// @param option_code Option code.
    /// @tparam ReturnType Type of the pointer object returned.
    ///
    /// @return Pointer to an option or NULL pointer if not found.
    template<typename ReturnType>
    ReturnType
    retrieveOption(const Host& host, const std::string& space,
                   const uint16_t option_code) const {
        ConstCfgOptionPtr cfg_option = host.getCfgOption4();
        if (cfg_option) {
            OptionDescriptor opt_desc = cfg_option->get(space, option_code);
            if (opt_desc.option_) {
                return (boost::dynamic_pointer_cast<
                        typename ReturnType::element_type>(opt_desc.option_));
            }
        }
        return (ReturnType());
    }


    /// @brief This utility method attempts to configure using specified
    ///        config and then returns requested pool from requested subnet
    ///
    /// @param config configuration to be applied
    /// @param subnet_index index of the subnet to be returned (0 - the first subnet)
    /// @param pool_index index of the pool within a subnet (0 - the first pool)
    /// @param pool [out] Pool pointer will be stored here (if found)
    void getPool(const std::string& config, size_t subnet_index,
                 size_t pool_index, PoolPtr& pool) {
        ConstElementPtr status;
        ConstElementPtr json;

        EXPECT_NO_THROW(json = parseDHCP4(config, true));
        EXPECT_NO_THROW(status = configureDhcp4Server(*srv_, json));
        ASSERT_TRUE(status);
        checkResult(status, 0);

        ConstCfgSubnets4Ptr subnets4 = CfgMgr::instance().getStagingCfg()->getCfgSubnets4();
        ASSERT_TRUE(subnets4);

        const Subnet4Collection* subnets = subnets4->getAll();
        ASSERT_TRUE(subnets);
        ASSERT_GE(subnets->size(), subnet_index + 1);

        const PoolCollection pools = subnets->at(subnet_index)->getPools(Lease::TYPE_V4);
        ASSERT_GE(pools.size(), pool_index + 1);

        pool = pools.at(pool_index);
        EXPECT_TRUE(pool);
    }

    boost::scoped_ptr<Dhcpv4Srv> srv_;  ///< DHCP4 server under test
    int rcode_;                         ///< Return code from element parsing
    ConstElementPtr comment_;           ///< Reason for parse fail
    isc::dhcp::ClientClasses classify_; ///< used in client classification
};

/// The goal of this test is to verify that the code accepts only
/// valid commands and malformed or unsupported parameters are rejected.
TEST_F(Dhcp4ParserTest, bogusCommand) {

    ConstElementPtr x;

    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_,
                    parseJSON("{\"bogus\": 5}")));

    // returned value must be 1 (configuration parse error)
    checkResult(x, 1);

    // it should be refused by syntax too
    EXPECT_THROW(parseDHCP4("{\"bogus\": 5}"), Dhcp4ParseError);
}

/// The goal of this test is to verify if wrongly defined subnet will
/// be rejected. Properly defined subnet must include at least one
/// pool definition.
TEST_F(Dhcp4ParserTest, emptySubnet) {

    ConstElementPtr json;
    EXPECT_NO_THROW(json = parseDHCP4("{ " + genIfaceConfig() + "," +
                                      "\"rebind-timer\": 2000, "
                                      "\"renew-timer\": 1000, "
                                      "\"subnet4\": [  ], "
                                      "\"valid-lifetime\": 4000 }"));

    ConstElementPtr status;
    EXPECT_NO_THROW(status = configureDhcp4Server(*srv_, json));

    // returned value should be 0 (success)
    checkResult(status, 0);
}

/// Check that the renew-timer doesn't have to be specified, in which case
/// it is marked unspecified in the Subnet.
TEST_F(Dhcp4ParserTest, unspecifiedRenewTimer) {

    string config = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\" } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    ConstElementPtr status;
    EXPECT_NO_THROW(status = configureDhcp4Server(*srv_, json));

    // returned value should be 0 (success)
    checkResult(status, 0);

    Subnet4Ptr subnet = CfgMgr::instance().getStagingCfg()->
        getCfgSubnets4()->selectSubnet(IOAddress("192.0.2.200"));
    ASSERT_TRUE(subnet);
    EXPECT_FALSE(subnet->getT1().unspecified());
    EXPECT_FALSE(subnet->getT2().unspecified());
    EXPECT_EQ(900, subnet->getT1()); // that's the default value
    EXPECT_EQ(2000, subnet->getT2());
    EXPECT_EQ(4000, subnet->getValid());

    // Check that subnet-id is 1
    EXPECT_EQ(1, subnet->getID());

}

/// Check that the rebind-timer doesn't have to be specified, in which case
/// it is marked unspecified in the Subnet.
TEST_F(Dhcp4ParserTest, unspecifiedRebindTimer) {

    string config = "{ " + genIfaceConfig() + "," +
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\" } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    ConstElementPtr status;
    EXPECT_NO_THROW(status = configureDhcp4Server(*srv_, json));

    // returned value should be 0 (success)
    checkResult(status, 0);

    Subnet4Ptr subnet = CfgMgr::instance().getStagingCfg()->
        getCfgSubnets4()->selectSubnet(IOAddress("192.0.2.200"));
    ASSERT_TRUE(subnet);
    EXPECT_FALSE(subnet->getT1().unspecified());
    EXPECT_EQ(1000, subnet->getT1());
    EXPECT_FALSE(subnet->getT2().unspecified());
    EXPECT_EQ(1800, subnet->getT2()); // that's the default value
    EXPECT_EQ(4000, subnet->getValid());

    // Check that subnet-id is 1
    EXPECT_EQ(1, subnet->getID());
}

/// The goal of this test is to verify if defined subnet uses global
/// parameter timer definitions.
TEST_F(Dhcp4ParserTest, subnetGlobalDefaults) {

    string config = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\" } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    ConstElementPtr status;
    EXPECT_NO_THROW(status = configureDhcp4Server(*srv_, json));

    // check if returned status is OK
    checkResult(status, 0);

    // Now check if the configuration was indeed handled and we have
    // expected pool configured.
    Subnet4Ptr subnet = CfgMgr::instance().getStagingCfg()->
        getCfgSubnets4()->selectSubnet(IOAddress("192.0.2.200"));
    ASSERT_TRUE(subnet);
    EXPECT_EQ(1000, subnet->getT1());
    EXPECT_EQ(2000, subnet->getT2());
    EXPECT_EQ(4000, subnet->getValid());

    // Check that subnet-id is 1
    EXPECT_EQ(1, subnet->getID());
}

// Goal of this test is to verify that multiple subnets get unique
// subnet-ids. Also, test checks that it's possible to do reconfiguration
// multiple times.
TEST_F(Dhcp4ParserTest, multipleSubnets) {
    ConstElementPtr x;
    // Collection of four subnets for which subnet ids should be
    // autogenerated - ids are unspecified or set to 0.
    string config = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\" "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.3.101 - 192.0.3.150\" } ],"
        "    \"subnet\": \"192.0.3.0/24\", "
        "    \"id\": 0 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.4.101 - 192.0.4.150\" } ],"
        "    \"subnet\": \"192.0.4.0/24\" "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.5.101 - 192.0.5.150\" } ],"
        "    \"subnet\": \"192.0.5.0/24\" "
        " } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    int cnt = 0; // Number of reconfigurations

    do {
        EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
        checkResult(x, 0);

        CfgMgr::instance().commit();

        const Subnet4Collection* subnets =
            CfgMgr::instance().getCurrentCfg()->getCfgSubnets4()->getAll();
        ASSERT_TRUE(subnets);
        ASSERT_EQ(4, subnets->size()); // We expect 4 subnets

        // Check subnet-ids of each subnet (it should be monotonously increasing)
        EXPECT_EQ(1, subnets->at(0)->getID());
        EXPECT_EQ(2, subnets->at(1)->getID());
        EXPECT_EQ(3, subnets->at(2)->getID());
        EXPECT_EQ(4, subnets->at(3)->getID());

        // Repeat reconfiguration process 10 times and check that the subnet-id
        // is set to the same value. Technically, just two iterations would be
        // sufficient, but it's nice to have a test that exercises reconfiguration
        // a bit.
    } while (++cnt < 10);
}

// This test checks that it is possible to assign arbitrary ids for subnets.
TEST_F(Dhcp4ParserTest, multipleSubnetsExplicitIDs) {
    ConstElementPtr x;
    // Four subnets with arbitrary subnet ids.
    string config = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\", "
        "    \"id\": 1024 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.3.101 - 192.0.3.150\" } ],"
        "    \"subnet\": \"192.0.3.0/24\", "
        "    \"id\": 100 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.4.101 - 192.0.4.150\" } ],"
        "    \"subnet\": \"192.0.4.0/24\", "
        "    \"id\": 1 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.5.101 - 192.0.5.150\" } ],"
        "    \"subnet\": \"192.0.5.0/24\", "
        "    \"id\": 34 "
        " } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    int cnt = 0; // Number of reconfigurations
    do {
        EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
        checkResult(x, 0);

        CfgMgr::instance().commit();

        const Subnet4Collection* subnets =
            CfgMgr::instance().getCurrentCfg()->getCfgSubnets4()->getAll();
        ASSERT_TRUE(subnets);
        ASSERT_EQ(4, subnets->size()); // We expect 4 subnets

        // Verify that subnet ids are as expected.
        EXPECT_EQ(1024, subnets->at(0)->getID());
        EXPECT_EQ(100, subnets->at(1)->getID());
        EXPECT_EQ(1, subnets->at(2)->getID());
        EXPECT_EQ(34, subnets->at(3)->getID());

        // Repeat reconfiguration process 10 times and check that the subnet-id
        // is set to the same value.
    } while (++cnt < 3);
}

// Check that the configuration with two subnets having the same id is rejected.
TEST_F(Dhcp4ParserTest, multipleSubnetsOverlapingIDs) {
    ConstElementPtr x;
    // Four subnets, two of them having the same id.
    string config = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\", "
        "    \"id\": 1024 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.3.101 - 192.0.3.150\" } ],"
        "    \"subnet\": \"192.0.3.0/24\", "
        "    \"id\": 100 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.4.101 - 192.0.4.150\" } ],"
        "    \"subnet\": \"192.0.4.0/24\", "
        "    \"id\": 1024 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.5.101 - 192.0.5.150\" } ],"
        "    \"subnet\": \"192.0.5.0/24\", "
        "    \"id\": 34 "
        " } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
    checkResult(x, 1);
    EXPECT_TRUE(errorContainsPosition(x, "<string>"));
}

// Goal of this test is to verify that a previously configured subnet can be
// deleted in subsequent reconfiguration.
TEST_F(Dhcp4ParserTest, reconfigureRemoveSubnet) {
    ConstElementPtr x;

    // All four subnets
    string config4 = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\", "
        "    \"id\": 1 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.3.101 - 192.0.3.150\" } ],"
        "    \"subnet\": \"192.0.3.0/24\", "
        "    \"id\": 2 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.4.101 - 192.0.4.150\" } ],"
        "    \"subnet\": \"192.0.4.0/24\", "
        "    \"id\": 3 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.5.101 - 192.0.5.150\" } ],"
        "    \"subnet\": \"192.0.5.0/24\", "
        "    \"id\": 4 "
        " } ],"
        "\"valid-lifetime\": 4000 }";

    // Three subnets (the last one removed)
    string config_first3 = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\", "
        "    \"id\": 1 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\":  \"192.0.3.101 - 192.0.3.150\" } ],"
        "    \"subnet\": \"192.0.3.0/24\", "
        "    \"id\": 2 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.4.101 - 192.0.4.150\" } ],"
        "    \"subnet\": \"192.0.4.0/24\", "
        "    \"id\": 3 "
        " } ],"
        "\"valid-lifetime\": 4000 }";

    // Second subnet removed
    string config_second_removed = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\", "
        "    \"id\": 1 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.4.101 - 192.0.4.150\" } ],"
        "    \"subnet\": \"192.0.4.0/24\", "
        "    \"id\": 3 "
        " },"
        " {"
        "    \"pools\": [ { \"pool\": \"192.0.5.101 - 192.0.5.150\" } ],"
        "    \"subnet\": \"192.0.5.0/24\", "
        "    \"id\": 4 "
        " } ],"
        "\"valid-lifetime\": 4000 }";

    // CASE 1: Configure 4 subnets, then reconfigure and remove the
    // last one.

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config4));
    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
    checkResult(x, 0);

    const Subnet4Collection* subnets =
        CfgMgr::instance().getStagingCfg()->getCfgSubnets4()->getAll();
    ASSERT_TRUE(subnets);
    ASSERT_EQ(4, subnets->size()); // We expect 4 subnets

    CfgMgr::instance().clear();

    // Do the reconfiguration (the last subnet is removed)
    ASSERT_NO_THROW(json = parseDHCP4(config_first3));
    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
    checkResult(x, 0);

    subnets = CfgMgr::instance().getStagingCfg()->getCfgSubnets4()->getAll();
    ASSERT_TRUE(subnets);
    ASSERT_EQ(3, subnets->size()); // We expect 3 subnets now (4th is removed)

    // Check subnet-ids of each subnet (it should be monotonously increasing)
    EXPECT_EQ(1, subnets->at(0)->getID());
    EXPECT_EQ(2, subnets->at(1)->getID());
    EXPECT_EQ(3, subnets->at(2)->getID());

    CfgMgr::instance().clear();

    /// CASE 2: Configure 4 subnets, then reconfigure and remove one
    /// from in between (not first, not last)

    /// @todo: Uncomment subnet removal test as part of #3281.
    ASSERT_NO_THROW(json = parseDHCP4(config4));
    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
    checkResult(x, 0);

    CfgMgr::instance().clear();

    // Do reconfiguration
    ASSERT_NO_THROW(json = parseDHCP4(config_second_removed));
    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
    checkResult(x, 0);

    subnets = CfgMgr::instance().getStagingCfg()->getCfgSubnets4()->getAll();
    ASSERT_TRUE(subnets);
    ASSERT_EQ(3, subnets->size()); // We expect 4 subnets

    EXPECT_EQ(1, subnets->at(0)->getID());
    // The second subnet (with subnet-id = 2) is no longer there
    EXPECT_EQ(3, subnets->at(1)->getID());
    EXPECT_EQ(4, subnets->at(2)->getID());

}

/// @todo: implement subnet removal test as part of #3281.

// Checks if the next-server defined as global parameter is taken into
// consideration.
TEST_F(Dhcp4ParserTest, nextServerGlobal) {

    string config = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"next-server\": \"1.2.3.4\", "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"subnet\": \"192.0.2.0/24\" } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    ConstElementPtr status;
    EXPECT_NO_THROW(status = configureDhcp4Server(*srv_, json));

    // check if returned status is OK
    checkResult(status, 0);

    // Now check if the configuration was indeed handled and we have
    // expected pool configured.
    Subnet4Ptr subnet = CfgMgr::instance().getStagingCfg()->
        getCfgSubnets4()->selectSubnet(IOAddress("192.0.2.200"));
    ASSERT_TRUE(subnet);
    EXPECT_EQ("1.2.3.4", subnet->getSiaddr().toText());
}

// Checks if the next-server defined as subnet parameter is taken into
// consideration.
TEST_F(Dhcp4ParserTest, nextServerSubnet) {

    string config = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"
        "    \"next-server\": \"1.2.3.4\", "
        "    \"subnet\": \"192.0.2.0/24\" } ],"
        "\"valid-lifetime\": 4000 }";

    ConstElementPtr json;
    ASSERT_NO_THROW(json = parseDHCP4(config));

    ConstElementPtr status;
    EXPECT_NO_THROW(status = configureDhcp4Server(*srv_, json));

    // check if returned status is OK
    checkResult(status, 0);

    // Now check if the configuration was indeed handled and we have
    // expected pool configured.
    Subnet4Ptr subnet = CfgMgr::instance().getStagingCfg()->
        getCfgSubnets4()->selectSubnet(IOAddress("192.0.2.200"));
    ASSERT_TRUE(subnet);
    EXPECT_EQ("1.2.3.4", subnet->getSiaddr().toText());
}

// Test checks several negative scenarios for next-server configuration: bogus
// address, IPv6 adddress and empty string.
TEST_F(Dhcp4ParserTest, nextServerNegative) {
    IfaceMgrTestConfig test_config(true);

    // Config with junk instead of next-server address
    string config_bogus1 = "{ " + genIfaceConfig() + "," +
        "\"rebind-timer\": 2000, "
        "\"renew-timer\": 1000, "
        "\"subnet4\": [ { "
        "    \"pools\": [ { \"pool\": \"192.0.2.1 - 192.0.2.100\" } ],"