auditd-plugin-clickhouse/auditd-record.hpp

/*
 * auditd-plugin-clickhouse is an auditd plugin for sending auditd data
 * to clickhouse DB.
 * Copyright (C) 2019 Aleksei Nikiforov <darktemplar@basealt.ru>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 *
 */

#ifndef AUDITD_PLUGIN_CLICKHOUSE_RECORD_HPP
#define AUDITD_PLUGIN_CLICKHOUSE_RECORD_HPP

#include <memory>
#include <map>
#include <functional>
#include <string>

#include <stdint.h>

#include <boost/optional.hpp>

#include <auparse.h>
#include <libaudit.h>

#include <clickhouse-cpp/columns/column.h>

class AbstractRecordFieldFactory;

class AbstractRecordField
{
public:
	enum class Type
	{
		Int,
		String,
		InterpretedString
	};

	virtual ~AbstractRecordField() = default;

	virtual void addToColumn(const std::vector<clickhouse::ColumnRef> &columns) const = 0;
	virtual Type getType() const = 0;

	std::string getName() const { return m_name; }

protected:
	explicit AbstractRecordField(const std::string &name);
	AbstractRecordField(const AbstractRecordField &other) = default;
	AbstractRecordField& operator=(const AbstractRecordField &other) = default;

	std::string m_name;

	friend class AbstractRecordFieldFactory;
};

class AuditRecord
{
public:

private:
	time_t m_seconds;
	uint64_t m_milliseconds;
	uint64_t m_serial;
	std::string m_node; // skip processing node from record fields

	std::map<std::string, std::shared_ptr<AbstractRecordField> > m_fields;
};

class AbstractRecordFieldFactory
{
public:
	std::shared_ptr<AbstractRecordField> createFromAuditRecord(const std::string &name, auparse_state_t *record);

	static AbstractRecordFieldFactory& instance();

	template <typename RecordFieldType>
	class AuditRecordFieldRegister
	{
	public:
		explicit AuditRecordFieldRegister(auparse_type_t type)
		{
			AbstractRecordFieldFactory::instance().m_factoryMap[type] = &RecordFieldType::createRecord;
		}
	};

protected:
	AbstractRecordFieldFactory() = default;

	AbstractRecordFieldFactory(const AbstractRecordFieldFactory &other) = delete;
	AbstractRecordFieldFactory& operator=(const AbstractRecordFieldFactory &other) = delete;

	std::map<auparse_type_t, std::function<std::shared_ptr<AbstractRecordField>(const std::string &name, auparse_state_t *record)> > m_factoryMap;
};

class CommonStringRecordField: public AbstractRecordField
{
public:
	virtual void addToColumn(const std::vector<clickhouse::ColumnRef> &columns) const override;

protected:
	explicit CommonStringRecordField(const std::string &name);

	boost::optional<std::string> m_value;
};

class StringRecordField: public CommonStringRecordField
{
public:
	static std::shared_ptr<AbstractRecordField> createRecord(const std::string &name, auparse_state_t *record);

	virtual Type getType() const override;

protected:
	StringRecordField(const std::string &name, auparse_state_t *record);
};

class InterpretedStringRecordField: public CommonStringRecordField
{
public:
	static std::shared_ptr<AbstractRecordField> createRecord(const std::string &name, auparse_state_t *record);

	virtual Type getType() const override;

protected:
	InterpretedStringRecordField(const std::string &name, auparse_state_t *record);
};

class IntegerRecordField: public InterpretedStringRecordField
{
public:
	static std::shared_ptr<AbstractRecordField> createRecord(const std::string &name, auparse_state_t *record);

	virtual void addToColumn(const std::vector<clickhouse::ColumnRef> &columns) const override;
	virtual Type getType() const override;

protected:
	IntegerRecordField(const std::string &name, auparse_state_t *record);

	boost::optional<int> m_int_value;
};

#endif /* AUDITD_PLUGIN_CLICKHOUSE_RECORD_HPP */