Network: Add state checksum which is check in network sync

source.list

@@ -460,6 +460,7 @@ core/alloc_type.hpp
 core/backup_type.hpp
 core/bitmath_func.cpp
 core/bitmath_func.hpp
+core/checksum_func.hpp
 core/container_func.hpp
 core/dyn_arena_alloc.hpp
 core/endian_func.hpp

src/aircraft_cmd.cpp

@@ -40,6 +40,7 @@
 #include "disaster_vehicle.h"
 #include "newgrf_airporttiles.h"
 #include "framerate_type.h"
+#include "core/checksum_func.hpp"
 
 #include "table/strings.h"
 
@@ -2127,6 +2128,7 @@ static bool AircraftEventHandler(Aircraft *v, int loop)
 
 bool Aircraft::Tick()
 {
+	UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
 	if (!this->IsNormalAircraft()) return true;
 
 	this->tick_counter++;

src/core/checksum_func.hpp

@@ -0,0 +1,33 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD 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, version 2.
+ * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file checksum_func.hpp Checksum utility functions. */
+
+#ifndef CHECKSUM_FUNC_HPP
+#define CHECKSUM_FUNC_HPP
+
+#include "bitmath_func.hpp"
+
+struct SimpleChecksum64 {
+	uint64 state = 0;
+
+	void Update(uint64 input)
+	{
+		this->state = ROL(this->state, 1) ^ input ^ 0x123456789ABCDEF7ULL;
+	}
+};
+
+extern SimpleChecksum64 _state_checksum;
+
+inline void UpdateStateChecksum(uint64 input)
+{
+	_state_checksum.Update(input);
+}
+
+#endif /* CHECKSUM_FUNC_HPP */

src/core/random_func.hpp

@@ -12,6 +12,8 @@
 #ifndef RANDOM_FUNC_HPP
 #define RANDOM_FUNC_HPP
 
+#include "bitmath_func.hpp"
+
 #if defined(__APPLE__)
 	/* Apple already has Random declared */
 	#define Random OTTD_Random

src/disaster_vehicle.cpp

@@ -47,6 +47,7 @@
 #include "company_base.h"
 #include "core/random_func.hpp"
 #include "core/backup_type.hpp"
+#include "core/checksum_func.hpp"
 
 #include "table/strings.h"
 
@@ -707,6 +708,7 @@ static DisasterVehicleTickProc * const _disastervehicle_tick_procs[] = {
 
 bool DisasterVehicle::Tick()
 {
+	UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
 	return _disastervehicle_tick_procs[this->subtype](this);
 }
 

src/effectvehicle.cpp

@@ -18,6 +18,7 @@
 #include "animated_tile_func.h"
 #include "effectvehicle_func.h"
 #include "effectvehicle_base.h"
+#include "core/checksum_func.hpp"
 
 #include <algorithm>
 
@@ -670,6 +671,7 @@ EffectVehicle *CreateEffectVehicleRel(const Vehicle *v, int x, int y, int z, Eff
 
 bool EffectVehicle::Tick()
 {
+	UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
 	return _effect_tick_procs[this->subtype](this);
 }
 

src/network/network.cpp

@@ -35,6 +35,7 @@
 #include "../core/pool_func.hpp"
 #include "../gfx_func.h"
 #include "../error.h"
+#include "../core/checksum_func.hpp"
 
 #include "../safeguards.h"
 
@@ -74,6 +75,7 @@ uint32 _sync_seed_1;                  ///< Seed to compare during sync checks.
 #ifdef NETWORK_SEND_DOUBLE_SEED
 uint32 _sync_seed_2;                  ///< Second part of the seed.
 #endif
+uint64 _sync_state_checksum;          ///< State checksum to compare during sync checks.
 uint32 _sync_frame;                   ///< The frame to perform the sync check.
 bool _network_first_time;             ///< Whether we have finished joining or not.
 bool _network_udp_server;             ///< Is the UDP server started?
@@ -1028,6 +1030,7 @@ void NetworkGameLoop()
 #ifdef NETWORK_SEND_DOUBLE_SEED
 		_sync_seed_2 = _random.state[1];
 #endif
+		_sync_state_checksum = _state_checksum.state;
 
 		NetworkServer_Tick(send_frame);
 	} else {

src/network/network_client.cpp

@@ -32,6 +32,7 @@
 #include "../core/backup_type.hpp"
 #include "../thread.h"
 #include "../crashlog.h"
+#include "../core/checksum_func.hpp"
 
 #include "table/strings.h"
 
@@ -282,9 +283,9 @@ void ClientNetworkGameSocketHandler::ClientError(NetworkRecvStatus res)
 	if (_sync_frame != 0) {
 		if (_sync_frame == _frame_counter) {
 #ifdef NETWORK_SEND_DOUBLE_SEED
-			if (_sync_seed_1 != _random.state[0] || _sync_seed_2 != _random.state[1]) {
+			if (_sync_seed_1 != _random.state[0] || _sync_seed_2 != _random.state[1] || _sync_state_checksum != _state_checksum.state) {
 #else
-			if (_sync_seed_1 != _random.state[0]) {
+			if (_sync_seed_1 != _random.state[0] || _sync_state_checksum != _state_checksum.state) {
 #endif
 				NetworkError(STR_NETWORK_ERROR_DESYNC);
 				DEBUG(desync, 1, "sync_err: date{%08x; %02x; %02x}", _date, _date_fract, _tick_skip_counter);
@@ -945,6 +946,7 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_FRAME(Packet *p
 #ifdef NETWORK_SEND_DOUBLE_SEED
 		_sync_seed_2 = p->Recv_uint32();
 #endif
+		_sync_state_checksum = p->Recv_uint64();
 	}
 #endif
 	/* Receive the token. */
@@ -972,6 +974,7 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_SYNC(Packet *p)
 #ifdef NETWORK_SEND_DOUBLE_SEED
 	_sync_seed_2 = p->Recv_uint32();
 #endif
+	_sync_state_checksum = p->Recv_uint64();
 
 	return NETWORK_RECV_STATUS_OKAY;
 }

src/network/network_internal.h

@@ -118,6 +118,7 @@ extern uint32 _sync_seed_1;
 #ifdef NETWORK_SEND_DOUBLE_SEED
 extern uint32 _sync_seed_2;
 #endif
+extern uint64 _sync_state_checksum;
 extern uint32 _sync_frame;
 extern bool _network_first_time;
 /* Vars needed for the join-GUI */

src/network/network_server.cpp

@@ -689,6 +689,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendFrame()
 #ifdef NETWORK_SEND_DOUBLE_SEED
 	p->Send_uint32(_sync_seed_2);
 #endif
+	p->Send_uint64(_sync_state_checksum);
 #endif
 
 	/* If token equals 0, we need to make a new token and send that. */
@@ -711,6 +712,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendSync()
 #ifdef NETWORK_SEND_DOUBLE_SEED
 	p->Send_uint32(_sync_seed_2);
 #endif
+	p->Send_uint64(_sync_state_checksum);
 	this->SendPacket(p);
 	return NETWORK_RECV_STATUS_OKAY;
 }

src/openttd.cpp

@@ -77,6 +77,7 @@
 #include "string_func_extra.h"
 #include "industry.h"
 #include "cargopacket.h"
+#include "core/checksum_func.hpp"
 
 #include "linkgraph/linkgraphschedule.h"
 #include "tracerestrict.h"
@@ -103,6 +104,8 @@ GameEventFlags _game_events_overall;
 
 time_t _game_load_time;
 
+SimpleChecksum64 _state_checksum;
+
 /**
  * Error handling for fatal user errors.
  * @param s the string to print.
@@ -1749,6 +1752,11 @@ void StateGameLoop()
 		CallWindowGameTickEvent();
 		NewsLoop();
 		cur_company.Restore();
+
+		Company *c;
+		FOR_ALL_COMPANIES(c) {
+			UpdateStateChecksum(c->money);
+		}
 	}
 
 	assert(IsLocalCompany());

src/roadveh_cmd.cpp

@@ -39,6 +39,7 @@
 #include "framerate_type.h"
 #include "scope_info.h"
 #include "string_func.h"
+#include "core/checksum_func.hpp"
 
 #include "table/strings.h"
 
@@ -1061,6 +1062,7 @@ static Trackdir RoadFindPathToDest(RoadVehicle *v, TileIndex tile, DiagDirection
 
 		default: NOT_REACHED();
 	}
+	UpdateStateChecksum((((uint64) v->index) << 32) | (path_found << 16) | best_track);
 	v->HandlePathfindingResult(path_found);
 
 found_best_track:;
@@ -1726,6 +1728,8 @@ Money RoadVehicle::GetRunningCost() const
 
 bool RoadVehicle::Tick()
 {
+	UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
+	UpdateStateChecksum((((uint64) this->state) << 32) | this->frame);
 	if (this->IsFrontEngine()) {
 		if (!(this->IsRoadVehicleStopped())) this->running_ticks++;
 		return RoadVehController(this);

src/saveload/extended_ver_sl.cpp

@@ -108,6 +108,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_GAME_EVENTS,            XSCF_NULL,                1,   1, "game_events",               nullptr, nullptr, nullptr        },
 	{ XSLFI_ROAD_LAYOUT_CHANGE_CTR, XSCF_NULL,                1,   1, "road_layout_change_ctr",    nullptr, nullptr, nullptr        },
 	{ XSLFI_TOWN_CARGO_MATRIX,      XSCF_NULL,                1,   1, "town_cargo_matrix",         nullptr, nullptr, nullptr        },
+	{ XSLFI_STATE_CHECKSUM,         XSCF_NULL,                1,   1, "state_checksum",            nullptr, nullptr, nullptr        },
 	{ XSLFI_DEBUG,                  XSCF_IGNORABLE_ALL,       1,   1, "debug",                     nullptr, nullptr, "DBGL"      },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
 };

src/saveload/extended_ver_sl.h

@@ -75,6 +75,7 @@ enum SlXvFeatureIndex {
 	XSLFI_GAME_EVENTS,                            ///< Game event flags
 	XSLFI_ROAD_LAYOUT_CHANGE_CTR,                 ///< Road layout change counter
 	XSLFI_TOWN_CARGO_MATRIX,                      ///< Town cargo matrix savegame format changes
+	XSLFI_STATE_CHECKSUM,                         ///< State checksum
 	XSLFI_DEBUG,                                  ///< Debugging info
 
 	XSLFI_RIFF_HEADER_60_BIT,                     ///< Size field in RIFF chunk header is 60 bit

src/saveload/misc_sl.cpp

@@ -19,6 +19,7 @@
 #include "../core/random_func.hpp"
 #include "../fios.h"
 #include "../road_type.h"
+#include "../core/checksum_func.hpp"
 
 #include "saveload.h"
 
@@ -86,6 +87,7 @@ static const SaveLoadGlobVarList _date_desc[] = {
 	SLE_CONDNULL(2, SL_MIN_VERSION, SLV_120),
 	    SLEG_VAR(_random.state[0],        SLE_UINT32),
 	    SLEG_VAR(_random.state[1],        SLE_UINT32),
+	SLEG_CONDVAR_X(_state_checksum.state, SLE_UINT64,         SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_STATE_CHECKSUM)),
 	SLE_CONDNULL(1,  SL_MIN_VERSION,  SLV_10),
 	SLE_CONDNULL(4, SLV_10, SLV_120),
 	    SLEG_VAR(_cur_company_tick_index, SLE_FILE_U8  | SLE_VAR_U32),
@@ -114,6 +116,7 @@ static const SaveLoadGlobVarList _date_check_desc[] = {
 	SLE_CONDNULL(2, SL_MIN_VERSION, SLV_120),
 	    SLE_NULL(4),                       // _random.state[0]
 	    SLE_NULL(4),                       // _random.state[1]
+	SLE_CONDNULL_X(8, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_STATE_CHECKSUM)), // _state_checksum.state
 	SLE_CONDNULL(1,  SL_MIN_VERSION,  SLV_10),
 	SLE_CONDNULL(4, SLV_10, SLV_120),
 	    SLE_NULL(1),                       // _cur_company_tick_index

src/ship_cmd.cpp

@@ -36,6 +36,7 @@
 #include "tunnelbridge_map.h"
 #include "zoom_func.h"
 #include "framerate_type.h"
+#include "core/checksum_func.hpp"
 
 #include "table/strings.h"
 
@@ -523,6 +524,7 @@ static Track ChooseShipTrack(Ship *v, TileIndex tile, DiagDirection enterdir, Tr
 			default: NOT_REACHED();
 		}
 	}
+	UpdateStateChecksum((((uint64) v->index) << 32) | (path_found << 16) | track);
 
 	v->HandlePathfindingResult(path_found);
 	return track;
@@ -948,6 +950,7 @@ reverse_direction:
 
 bool Ship::Tick()
 {
+	UpdateStateChecksum((((uint64) this->x_pos) << 32) | this->y_pos);
 	if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;
 
 	ShipController(this);

src/train_cmd.cpp

@@ -43,6 +43,7 @@
 #include "engine_func.h"
 #include "bridge_signal_map.h"
 #include "scope_info.h"
+#include "core/checksum_func.hpp"
 
 #include "table/strings.h"
 #include "table/train_cmd.h"
@@ -3127,6 +3128,7 @@ static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir,
 		TileIndex new_tile = res_dest.tile;
 
 		Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
+		UpdateStateChecksum((((uint64) v->index) << 32) | (path_found << 16) | next_track);
 		if (new_tile == tile) best_track = next_track;
 		v->HandlePathfindingResult(path_found);
 	}
@@ -4971,6 +4973,7 @@ Money Train::GetRunningCost() const
  */
 bool Train::Tick()
 {
+	UpdateStateChecksum((((uint64) this->x_pos) << 32) | (this->y_pos << 16) | this->track );
 	if (this->IsFrontEngine()) {
 		if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;