From d4c76258e37337ea585cf24d8e05b50a30fa307d Mon Sep 17 00:00:00 2001 From: Loic Blot Date: Tue, 4 Oct 2016 18:17:12 +0200 Subject: [PATCH] Chat: new settings to prevent spam Added the following chat coreside features * Chat messages length limit * Message rate limiting * Message rate kicking Note: * handleChat now takes RemotePlayer pointer instead of u16 to remove useless lookups --- builtin/settingtypes.txt | 9 +++++ minetest.conf.example | 14 +++++++- src/defaultsettings.cpp | 3 ++ src/network/serverpackethandler.cpp | 10 +++--- src/player.cpp | 56 ++++++++++++++++++++++++++++- src/player.h | 16 ++++++++- src/server.cpp | 25 +++++++++++-- src/server.h | 3 +- 8 files changed, 125 insertions(+), 11 deletions(-) diff --git a/builtin/settingtypes.txt b/builtin/settingtypes.txt index 15fab0f30..95cc826a0 100644 --- a/builtin/settingtypes.txt +++ b/builtin/settingtypes.txt @@ -774,6 +774,15 @@ time_speed (Time speed) int 72 # Interval of saving important changes in the world, stated in seconds. server_map_save_interval (Map save interval) float 5.3 +# Set the maximum character length of a chat message sent by clients. +# chat_message_max_size int 500 + +# Limit a single player to send X messages per 10 seconds. +# chat_message_limit_per_10sec float 10.0 + +# Kick player if send more than X messages per 10 seconds. +# chat_message_limit_trigger_kick int 50 + [**Physics] movement_acceleration_default (Default acceleration) float 3 diff --git a/minetest.conf.example b/minetest.conf.example index 9c8015625..b1b202786 100644 --- a/minetest.conf.example +++ b/minetest.conf.example @@ -933,6 +933,18 @@ # type: float # server_map_save_interval = 5.3 +# Set the maximum character length of a chat message sent by clients. (0 to disable) +# type: integer +# chat_message_max_size = 500 + +# Limit a single player to send X messages per 10 seconds. (0 to disable) +# type: float +# chat_message_limit_per_10sec = 8.0 + +# Kick player if send more than X messages per 10 seconds. (0 to disable) +# type: integer +# chat_message_limit_trigger_kick = 50 + ### Physics # type: float @@ -1523,7 +1535,7 @@ # profiler.default_report_format = txt # The file path relative to your worldpath in which profiles will be saved to. -# +# # type: string # profiler.report_path = "" diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp index 4520bac2f..00c233a42 100644 --- a/src/defaultsettings.cpp +++ b/src/defaultsettings.cpp @@ -285,6 +285,9 @@ void set_default_settings(Settings *settings) settings->setDefault("server_unload_unused_data_timeout", "29"); settings->setDefault("max_objects_per_block", "49"); settings->setDefault("server_map_save_interval", "5.3"); + settings->setDefault("chat_message_max_size", "500"); + settings->setDefault("chat_message_limit_per_10sec", "8.0"); + settings->setDefault("chat_message_limit_trigger_kick", "50"); settings->setDefault("sqlite_synchronous", "2"); settings->setDefault("full_block_send_enable_min_time_from_building", "2.0"); settings->setDefault("dedicated_server_step", "0.1"); diff --git a/src/network/serverpackethandler.cpp b/src/network/serverpackethandler.cpp index 1bcb78a8a..a8bfd9068 100644 --- a/src/network/serverpackethandler.cpp +++ b/src/network/serverpackethandler.cpp @@ -1065,7 +1065,7 @@ void Server::handleCommand_ChatMessage(NetworkPacket* pkt) std::wstring wname = narrow_to_wide(name); std::wstring answer_to_sender = handleChat(name, wname, message, - true, pkt->getPeerId()); + true, dynamic_cast(player)); if (!answer_to_sender.empty()) { // Send the answer to sender SendChatMessage(pkt->getPeerId(), answer_to_sender); @@ -1656,16 +1656,16 @@ void Server::handleCommand_Interact(NetworkPacket* pkt) } } // action == 4 - + /* 5: rightclick air */ else if (action == 5) { ItemStack item = playersao->getWieldedItem(); - - actionstream << player->getName() << " activates " + + actionstream << player->getName() << " activates " << item.name << std::endl; - + if (m_script->item_OnSecondaryUse( item, playersao)) { if( playersao->setWieldedItem(item)) { diff --git a/src/player.cpp b/src/player.cpp index 5949712a5..fd72d63b6 100644 --- a/src/player.cpp +++ b/src/player.cpp @@ -227,10 +227,25 @@ void Player::clearHud() } } +// static config cache for remoteplayer +bool RemotePlayer::m_setting_cache_loaded = false; +float RemotePlayer::m_setting_chat_message_limit_per_10sec = 0.0f; +u16 RemotePlayer::m_setting_chat_message_limit_trigger_kick = 0; + RemotePlayer::RemotePlayer(IGameDef *gamedef, const char *name): Player(gamedef, name), - m_sao(NULL) + m_sao(NULL), + m_last_chat_message_sent(time(NULL)), + m_chat_message_allowance(5.0f), + m_message_rate_overhead(0) { + if (!RemotePlayer::m_setting_cache_loaded) { + RemotePlayer::m_setting_chat_message_limit_per_10sec = + g_settings->getFloat("chat_message_limit_per_10sec"); + RemotePlayer::m_setting_chat_message_limit_trigger_kick = + g_settings->getU16("chat_message_limit_trigger_kick"); + RemotePlayer::m_setting_cache_loaded = true; + } movement_acceleration_default = g_settings->getFloat("movement_acceleration_default") * BS; movement_acceleration_air = g_settings->getFloat("movement_acceleration_air") * BS; movement_acceleration_fast = g_settings->getFloat("movement_acceleration_fast") * BS; @@ -304,3 +319,42 @@ void RemotePlayer::setPosition(const v3f &position) m_sao->setBasePosition(position); } +const RemotePlayerChatResult RemotePlayer::canSendChatMessage() +{ + // Rate limit messages + u32 now = time(NULL); + float time_passed = now - m_last_chat_message_sent; + m_last_chat_message_sent = now; + + // If this feature is disabled + if (m_setting_chat_message_limit_per_10sec <= 0.0) { + return RPLAYER_CHATRESULT_OK; + } + + m_chat_message_allowance += time_passed * (m_setting_chat_message_limit_per_10sec / 8.0f); + if (m_chat_message_allowance > m_setting_chat_message_limit_per_10sec) { + m_chat_message_allowance = m_setting_chat_message_limit_per_10sec; + } + + if (m_chat_message_allowance < 1.0f) { + infostream << "Player " << m_name + << " chat limited due to excessive message amount." << std::endl; + + // Kick player if flooding is too intensive + m_message_rate_overhead++; + if (m_message_rate_overhead > RemotePlayer::m_setting_chat_message_limit_trigger_kick) { + return RPLAYER_CHATRESULT_KICK; + } + + return RPLAYER_CHATRESULT_FLOODING; + } + + // Reinit message overhead + if (m_message_rate_overhead > 0) { + m_message_rate_overhead = 0; + } + + m_chat_message_allowance -= 1.0f; + return RPLAYER_CHATRESULT_OK; +} + diff --git a/src/player.h b/src/player.h index eab00bb04..f38effa9d 100644 --- a/src/player.h +++ b/src/player.h @@ -439,7 +439,11 @@ private: Mutex m_mutex; }; - +enum RemotePlayerChatResult { + RPLAYER_CHATRESULT_OK, + RPLAYER_CHATRESULT_FLOODING, + RPLAYER_CHATRESULT_KICK, +}; /* Player on the server */ @@ -457,8 +461,18 @@ public: { m_sao = sao; } void setPosition(const v3f &position); + const RemotePlayerChatResult canSendChatMessage(); + private: PlayerSAO *m_sao; + + static bool m_setting_cache_loaded; + static float m_setting_chat_message_limit_per_10sec; + static u16 m_setting_chat_message_limit_trigger_kick; + + u32 m_last_chat_message_sent; + float m_chat_message_allowance; + u16 m_message_rate_overhead; }; #endif diff --git a/src/server.cpp b/src/server.cpp index fb241f179..c615aee13 100644 --- a/src/server.cpp +++ b/src/server.cpp @@ -358,6 +358,7 @@ Server::Server( add_legacy_abms(m_env, m_nodedef); m_liquid_transform_every = g_settings->getFloat("liquid_update"); + m_max_chatmessage_length = g_settings->getU16("chat_message_max_size"); } Server::~Server() @@ -2734,8 +2735,7 @@ void Server::handleChatInterfaceEvent(ChatEvent *evt) } std::wstring Server::handleChat(const std::string &name, const std::wstring &wname, - const std::wstring &wmessage, bool check_shout_priv, - u16 peer_id_to_avoid_sending) + const std::wstring &wmessage, bool check_shout_priv, RemotePlayer *player) { // If something goes wrong, this player is to blame RollbackScopeActor rollback_scope(m_rollback, @@ -2753,6 +2753,26 @@ std::wstring Server::handleChat(const std::string &name, const std::wstring &wna if (ate) return L""; + switch (player->canSendChatMessage()) { + case RPLAYER_CHATRESULT_FLOODING: { + std::wstringstream ws; + ws << L"You cannot send more messages. You are limited to " + << g_settings->getFloat("chat_message_limit_per_10sec") + << " messages per 10 seconds."; + return ws.str(); + } + case RPLAYER_CHATRESULT_KICK: + DenyAccess_Legacy(player->peer_id, L"You have been kicked due to message flooding."); + return L""; + case RPLAYER_CHATRESULT_OK: break; + default: FATAL_ERROR("Unhandled chat filtering result found."); + } + + if (m_max_chatmessage_length > 0 && wmessage.length() > m_max_chatmessage_length) { + return L"Your message exceed the maximum chat message limit set on the server. " + "It was refused. Send a shorter message"; + } + // Commands are implemented in Lua, so only catch invalid // commands that were not "eaten" and send an error back if (wmessage[0] == L'/') { @@ -2787,6 +2807,7 @@ std::wstring Server::handleChat(const std::string &name, const std::wstring &wna std::vector clients = m_clients.getClientIDs(); + u16 peer_id_to_avoid_sending = (player ? player->peer_id : PEER_ID_INEXISTENT); for (u16 i = 0; i < clients.size(); i++) { u16 cid = clients[i]; if (cid != peer_id_to_avoid_sending) diff --git a/src/server.h b/src/server.h index 7ee15a463..3ad894b38 100644 --- a/src/server.h +++ b/src/server.h @@ -487,7 +487,7 @@ private: std::wstring handleChat(const std::string &name, const std::wstring &wname, const std::wstring &wmessage, bool check_shout_priv = false, - u16 peer_id_to_avoid_sending = PEER_ID_INEXISTENT); + RemotePlayer *player = NULL); void handleAdminChat(const ChatEventChat *evt); v3f findSpawnPos(); @@ -522,6 +522,7 @@ private: // If true, do not allow multiple players and hide some multiplayer // functionality bool m_simple_singleplayer_mode; + u16 m_max_chatmessage_length; // Thread can set; step() will throw as ServerError MutexedVariable m_async_fatal_error;