Separate anticheat settings (#15040)

builtin/settingtypes.txt

@@ -884,8 +884,13 @@ default_privs (Default privileges) string interact, shout
 #    Privileges that players with basic_privs can grant
 basic_privs (Basic privileges) string interact, shout
 
-#    If enabled, disable cheat prevention in multiplayer.
+#    Server anticheat configuration.
-disable_anticheat (Disable anticheat) bool false
+#    Flags are positive. Uncheck the flag to disable corresponding anticheat module.
+anticheat_flags (Anticheat flags) flags digging,interaction,movement digging,interaction,movement
+
+#    Tolerance of movement cheat detector.
+#    Increase the value if players experience stuttery movement.
+anticheat_movement_tolerance (Anticheat movement tolerance) float 1.0 1.0
 
 #    If enabled, actions are recorded for rollback.
 #    This option is only read when server starts.

src/defaultsettings.cpp

@@ -25,6 +25,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "porting.h"
 #include "mapgen/mapgen.h" // Mapgen::setDefaultSettings
 #include "util/string.h"
+#include "server.h"
 
 
 /*
@@ -459,7 +460,9 @@ void set_default_settings()
 	settings->setDefault("enable_pvp", "true");
 	settings->setDefault("enable_mod_channels", "false");
 	settings->setDefault("disallow_empty_password", "false");
-	settings->setDefault("disable_anticheat", "false");
+	settings->setDefault("anticheat_flags", flagdesc_anticheat,
+		AC_DIGGING | AC_INTERACTION | AC_MOVEMENT);
+	settings->setDefault("anticheat_movement_tolerance", "1.0");
 	settings->setDefault("enable_rollback_recording", "false");
 	settings->setDefault("deprecated_lua_api_handling", "log");
 

src/migratesettings.h

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LGPL-2.1-or-later
 
 #include "settings.h"
+#include "server.h"
 
 void migrate_settings()
 {
@@ -19,4 +20,12 @@ void migrate_settings()
 		g_settings->setBool("touch_gui", value);
 		g_settings->remove("enable_touch");
 	}
+
+	// Disables anticheat
+	if (g_settings->existsLocal("disable_anticheat")) {
+		if (g_settings->getBool("disable_anticheat")) {
+			g_settings->setFlagStr("anticheat_flags", 0, flagdesc_anticheat);
+		}
+		g_settings->remove("disable_anticheat");
+	}
 }

src/network/serverpackethandler.cpp

@@ -1011,12 +1011,12 @@ void Server::handleCommand_Interact(NetworkPacket *pkt)
 	/*
 		Check that target is reasonably close
 	*/
-	static thread_local const bool enable_anticheat =
+	static thread_local const u32 anticheat_flags =
-			!g_settings->getBool("disable_anticheat");
+		g_settings->getFlagStr("anticheat_flags", flagdesc_anticheat, nullptr);
 
 	if ((action == INTERACT_START_DIGGING || action == INTERACT_DIGGING_COMPLETED ||
 			action == INTERACT_PLACE || action == INTERACT_USE) &&
-			enable_anticheat && !isSingleplayer()) {
+			(anticheat_flags & AC_INTERACTION) && !isSingleplayer()) {
 		v3f target_pos = player_pos;
 		if (pointed.type == POINTEDTHING_NODE) {
 			target_pos = intToFloat(pointed.node_undersurface, BS);
@@ -1119,7 +1119,7 @@ void Server::handleCommand_Interact(NetworkPacket *pkt)
 
 		/* Cheat prevention */
 		bool is_valid_dig = true;
-		if (enable_anticheat && !isSingleplayer()) {
+		if ((anticheat_flags & AC_DIGGING) && !isSingleplayer()) {
 			v3s16 nocheat_p = playersao->getNoCheatDigPos();
 			float nocheat_t = playersao->getNoCheatDigTime();
 			playersao->noCheatDigEnd();

src/server.h

@@ -81,6 +81,20 @@ struct PackedValue;
 struct ParticleParameters;
 struct ParticleSpawnerParameters;
 
+// Anticheat flags
+enum {
+	AC_DIGGING     = 0x01,
+	AC_INTERACTION = 0x02,
+	AC_MOVEMENT    = 0x04
+};
+
+constexpr const static FlagDesc flagdesc_anticheat[] = {
+	{"digging",     AC_DIGGING},
+	{"interaction", AC_INTERACTION},
+	{"movement",    AC_MOVEMENT},
+	{NULL,          0}
+};
+
 enum ClientDeletionReason {
 	CDR_LEAVE,
 	CDR_TIMEOUT,

src/server/player_sao.cpp

@@ -646,9 +646,12 @@ void PlayerSAO::setMaxSpeedOverride(const v3f &vel)
 
 bool PlayerSAO::checkMovementCheat()
 {
+	static thread_local const u32 anticheat_flags =
+		g_settings->getFlagStr("anticheat_flags", flagdesc_anticheat, nullptr);
+
 	if (m_is_singleplayer ||
 			isAttached() ||
-			g_settings->getBool("disable_anticheat")) {
+			!(anticheat_flags & AC_MOVEMENT)) {
 		m_last_good_position = m_base_position;
 		return false;
 	}
@@ -729,6 +732,11 @@ bool PlayerSAO::checkMovementCheat()
 		required_time = MYMAX(required_time, d_vert / s);
 	}
 
+	static thread_local float anticheat_movement_tolerance =
+		std::max(g_settings->getFloat("anticheat_movement_tolerance"), 1.0f);
+
+	required_time /= anticheat_movement_tolerance;
+
 	if (m_move_pool.grab(required_time)) {
 		m_last_good_position = m_base_position;
 	} else {