DOSGuard.hpp

//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2022, the clio developers.
 
    Permission to use, copy, modify, and 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
*/
//==============================================================================
 
#pragma once
 
#include "util/Mutex.hpp"
#include "util/log/Logger.hpp"
#include "util/newconfig/ConfigDefinition.hpp"
#include "web/dosguard/DOSGuardInterface.hpp"
#include "web/dosguard/WhitelistHandlerInterface.hpp"
 
#include <boost/asio.hpp>
#include <boost/iterator/transform_iterator.hpp>
#include <boost/system/error_code.hpp>
 
#include <cstdint>
#include <functional>
#include <string>
#include <string_view>
#include <unordered_map>
#include <unordered_set>
 
namespace web::dosguard {
 
class DOSGuard : public DOSGuardInterface {
    struct ClientState {
        std::uint32_t transferedByte = 0; 
        std::uint32_t requestsCount = 0;  
    };
 
    struct State {
        std::unordered_map<std::string, ClientState> ipState;
        std::unordered_map<std::string, std::uint32_t> ipConnCount;
    };
    util::Mutex<State> mtx_;
 
    std::reference_wrapper<WhitelistHandlerInterface const> whitelistHandler_;
 
    std::uint32_t const maxFetches_;
    std::uint32_t const maxConnCount_;
    std::uint32_t const maxRequestCount_;
    util::Logger log_{"RPC"};
 
public:
    DOSGuard(util::config::ClioConfigDefinition const& config, WhitelistHandlerInterface const& whitelistHandler);
 
    [[nodiscard]] bool
    isWhiteListed(std::string_view const ip) const noexcept override;
 
    [[nodiscard]] bool
    isOk(std::string const& ip) const noexcept override;
 
    void
    increment(std::string const& ip) noexcept override;
 
    void
    decrement(std::string const& ip) noexcept override;
 
    [[maybe_unused]] bool
    add(std::string const& ip, uint32_t numObjects) noexcept override;
 
    [[maybe_unused]] bool
    request(std::string const& ip) noexcept override;
 
    void
    clear() noexcept override;
 
private:
    [[nodiscard]] static std::unordered_set<std::string>
    getWhitelist(util::config::ClioConfigDefinition const& config);
};
 
}  // namespace web::dosguard