ferencd@0: #ifndef FLOOD_CHECK
ferencd@0: #define FLOOD_CHECK
ferencd@0: 
ferencd@0: #include <string>
ferencd@0: #include <map>
ferencd@0: #include <chrono>
ferencd@0: #include <mutex>
ferencd@0: 
ferencd@0: /**
ferencd@0:  * @brief The flood_check class will check if there is a flood attempt from some specific
ferencd@0:  * IP. The following is the method: If it can identify that in a given second a given IP
ferencd@0:  * has tried more than 100 (configurable) requests it will reject the requests without
ferencd@0:  * going further.
ferencd@0:  */
ferencd@0: class flood_check
ferencd@0: {
ferencd@0: public:
ferencd@0: 
ferencd@0:     static void attempt(std::string ip);
ferencd@0: 
ferencd@0: private:
ferencd@0: 
ferencd@0:     static std::mutex locker;
ferencd@0: 
ferencd@0:     // holds the flood attempts and when they have first occured
ferencd@0:     struct count_started
ferencd@0:     {
ferencd@0:         int count = 0;
ferencd@0:         std::time_t first_time = std::chrono::duration_cast<std::chrono::seconds>(std::chrono::system_clock::now().time_since_epoch()).count();
ferencd@0:     };
ferencd@0: 
ferencd@0:     // structures used to determine the flood rate / second
ferencd@0:     using flood_map = std::map<std::string, int>;
ferencd@0:     static std::map<std::time_t, flood_map> floods;
ferencd@0: 
ferencd@0:     // holds the flood attempts of a host. For each IP we have an attempt counter
ferencd@0:     // how many times it tried to flood us and when the last attempt happened
ferencd@0:     static std::map<std::string, count_started> hostd_flood;
ferencd@0: 
ferencd@0:     // holds the evil hosts that are flooding the system and how long they are locked out
ferencd@0:     // the content of this map is determined based on the content of the hostd_flood
ferencd@0:     // map. If a count from there reaches over 10 and the first_time of the
ferencd@0:     // entry is < 1 minute then we consider the host flooding us.
ferencd@0:     static std::map<std::string, std::time_t> rejected_hosts;
ferencd@0: 
ferencd@0:     // holds how many times the given host was suspended. Each suspension will give another minute to the host
ferencd@0:     static std::map<std::string, int> suspension_times;
ferencd@0: };
ferencd@0: 
ferencd@0: #endif // FLOOD_CHECK
ferencd@0: