Files
openttd-client/lib/openttd/protocol.py
T
kovagoadiandClaude f7ca395a4f
Continuous Integration / lint-and-security (pull_request) Failing after 19s
Continuous Integration / tests-and-coverage (pull_request) Successful in 24s
Put the AdminBridge GameScript under version control
The last commit noted in passing that the server-side half of the admin
GameScript channel "is not in this repo -- docker/config is gitignored --
so it has to be updated separately for any of this to work." That was true
of all nine features the README documents: list_vehicles, list_stations,
list_cargo, get_timetable, get_station, get_station_cargo, get_dispatch and
the event stream all answer from 705 lines of Squirrel that no clone could
reproduce, no reviewer could see, and CI never touched.

The bridge now lives in gamescript/AdminBridge/ with its own README, the
same arrangement docker/patches/ uses for the local JGRPP patches, and
docker-compose.yml bind-mounts it read-only over the container's
game/AdminBridge. docker/config stays ignored -- it also holds savegames,
downloaded content and generated config -- so the copy under it is now
shadowed and can be deleted. main.nut is byte-identical to what was running,
apart from the version work below.

Adds a version handshake, because the channel gives no way to tell a stale
bridge from a hung one: a bridge that does not recognise a command drops it
silently, so a client ahead of the server sees nothing but timeouts. The
bridge now answers get_version with its protocol version plus its command
and event catalogues, and get_bridge_version() raises when that is below
GS_BRIDGE_VERSION. It is opt-in rather than checked on connect: GameScripts
do not tick while the game is paused, so an automatic check would refuse to
connect to a paused server. A bridge older than 4 predates get_version
itself and can only fail by timing out, so the E2E test catches that and
reports it by name instead.

tests/test_gamescript.py gives CI a foothold on the GameScript without a
Squirrel toolchain: it parses the .nut files and pins the protocol version
across info.nut, main.nut and protocol.py, the event catalogue against
GameEventType, and the command table against the commands client.py sends.
The version has to be declared three times because a GameScript cannot read
its own info.nut at runtime -- GSController.GetVersion() returns the OpenTTD
version, not the script's.

info.nut also gains MinVersionToLoad() { return 1; }. The engine defaults it
to GetVersion(), so without it this bump would orphan every savegame pinned
to version 3: the scanner finds no compatible script and falls back with a
warning. The bridge keeps no savegame state, so any version can take over.

HandleCommand now dispatches through the same table get_version reports,
rather than an if/else chain, so the catalogue a client feature-detects
against cannot drift from what is implemented.

Co-Authored-By: Claude <[email protected]>
2026-08-31 19:06:33 +02:00

630 lines
21 KiB
Python

import struct
from enum import IntEnum, StrEnum
import monocypher
from openttd_protocol.wire.exceptions import SocketClosed
from openttd_protocol.wire.read import read_string, read_uint8, read_uint16, read_uint32
from openttd_protocol.wire.tcp import TCPProtocol
def write_varuint(buffer, value):
"""Encode a non-negative integer using OpenTTD's UTF-8-like varuint scheme."""
if value < 0:
raise ValueError("write_varuint requires a non-negative value")
thresholds = [1 << 7, 1 << 14, 1 << 21, 1 << 28, 1 << 35, 1 << 42, 1 << 49, 1 << 56]
for extra, limit in enumerate(thresholds):
if value < limit:
header_ones = (0xFF << (8 - extra)) & 0xFF
header = header_ones | (value >> (extra * 8))
buffer.append(header)
for i in range(extra - 1, -1, -1):
buffer.append((value >> (i * 8)) & 0xFF)
return
buffer.append(0xFF)
for i in range(7, -1, -1):
buffer.append((value >> (i * 8)) & 0xFF)
def read_varuint(data):
"""Decode a varuint written by write_varuint. Returns (value, rest)."""
header = data[0]
mask = 0x80
extra = 0
while header & mask:
extra += 1
mask >>= 1
value = header & (0x7F >> extra)
rest = data[1:]
for i in range(extra):
value = (value << 8) | rest[i]
return value, rest[extra:]
def write_varuint_signed(buffer, value):
"""Encode a signed integer using zigzag + write_varuint."""
zigzag = (value << 1) ^ (-1 if value < 0 else 0)
write_varuint(buffer, zigzag)
def read_varuint_signed(data):
"""Decode a signed varuint written by write_varuint_signed. Returns (value, rest)."""
zigzag, rest = read_varuint(data)
value = (zigzag >> 1) ^ -(zigzag & 1)
return value, rest
class GameCommand(IntEnum):
DeleteOrder = 51
InsertOrder = 52
ChangeTimetable = 174
SetVehicleOnTime = 176
AutofillTimetable = 177
SetTimetableStart = 180
# Scheduled dispatch (JGRPP)
SchDispatch = 205
SchDispatchAdd = 206
SchDispatchRemove = 207
SchDispatchSetDuration = 208
SchDispatchSetStartDate = 209
SchDispatchClear = 213
SchDispatchAddNewSchedule = 214
SchDispatchRemoveSchedule = 215
# Sentinel VehicleOrderID meaning "append to the end of the order list" for InsertOrder.
INVALID_VEH_ORDER_ID = 0xFFFF
class OrderType(IntEnum):
"""OrderType occupies bits 0-3 of an order's `type` byte (bits 6-7 hold OrderNonStopFlags)."""
GotoStation = 1
GotoDepot = 2
GotoWaypoint = 6
class OrderNonStopFlags(IntEnum):
"""Packed into bits 6-7 of an order's `type` byte."""
StopEverywhere = 0
NoStopAtIntermediate = 1
NoStopAtDestination = 2
NoStopAtAny = 3
class OrderStopLocation(IntEnum):
"""Packed into bits 4-5 of an order's `type` byte. Near-end/middle/through are train-only;
FarEnd is the only value the server accepts for every vehicle type, so it is the safe default."""
PlatformNearEnd = 0
PlatformMiddle = 1
PlatformFarEnd = 2
PlatformThrough = 3
class ModifyTimetableFlags(IntEnum):
WaitTime = 0
TravelTime = 1
TravelSpeed = 2
SetWaitFixed = 3
SetTravelFixed = 4
SetLeaveType = 5
AssignSchedule = 6
class ModifyTimetableCtrlFlag(IntEnum):
ClearField = 1 << 0
class PacketGameType(IntEnum):
ServerFull = 0
ServerBanned = 1
ClientJoin = 2
ServerError = 3
ClientUnused = 4
ServerUnused = 5
ServerGameInfo = 6
ClientGameInfo = 7
ServerNewGame = 8
ServerShutdown = 9
ServerGameInfoExtended = 10
ServerAuthenticationRequest = 11
ClientAuthenticationResponse = 12
ServerEnableEncryption = 13
ClientIdentify = 14
ServerCheckNewGRFs = 15
ClientNewGRFsChecked = 16
ServerNeedCompanyPassword = 17
ClientCompanyPassword = 18
ClientSettingsPassword = 19
ServerSettingsAccess = 20
ServerWelcome = 21
ServerClientInfo = 22
ClientGetMap = 23
ServerWaitForMap = 24
ServerMapBegin = 25
ServerMapSize = 26
ServerMapData = 27
ServerMapDone = 28
ClientMapOk = 29
ServerClientJoined = 30
ServerFrame = 31
ClientAck = 32
ServerSync = 33
ClientCommand = 34
ServerCommand = 35
ClientChat = 36
ServerChat = 37
ServerExternalChat = 38
ClientQuit = 47
ServerCompanyUpdate = 45
PACKET_END = 100
class PacketAdminType(IntEnum):
AdminJoin = 0
AdminQuit = 1
AdminUpdateFrequency = 2
AdminPoll = 3
AdminChat = 4
AdminRcon = 5
AdminGamescript = 6
AdminPing = 7
AdminExternalChat = 8
AdminJoinSecure = 9
AdminAuthResponse = 10
ServerFull = 100
ServerBanned = 101
ServerError = 102
ServerProtocol = 103
ServerWelcome = 104
ServerNewGame = 105
ServerShutdown = 106
ServerDate = 107
ServerClientJoin = 108
ServerClientInfo = 109
ServerClientUpdate = 110
ServerClientQuit = 111
ServerClientError = 112
ServerCompanyNew = 113
ServerCompanyInfo = 114
ServerCompanyUpdate = 115
ServerCompanyRemove = 116
ServerCompanyEconomy = 117
ServerCompanyStats = 118
ServerChat = 119
ServerRcon = 120
ServerConsole = 121
ServerCmdNames = 122
ServerCmdLoggingOld = 123
ServerGamescript = 124
ServerRconEnd = 125
ServerPong = 126
ServerCmdLogging = 127
ServerAuthRequest = 128
ServerEnableEncryption = 129
PACKET_END = 130
class AdminUpdateFrequency(IntEnum):
Poll = 1 << 0
Daily = 1 << 1
Weekly = 1 << 2
Monthly = 1 << 3
Quarterly = 1 << 4
Annually = 1 << 5
Automatic = 1 << 6
class AdminUpdateType(IntEnum):
Date = 0
ClientInfo = 1
CompanyInfo = 2
CompanyEconomy = 3
CompanyStats = 4
Chat = 5
Console = 6
CmdNames = 7
CmdLogging = 8
Gamescript = 9
End = 10
class NetworkAuthenticationMethod(IntEnum):
X25519_KeyExchangeOnly = 0
X25519_PAKE = 1
X25519_AuthorizedKey = 2
# Version of the AdminBridge GameScript's JSON protocol this client is written against. The
# bridge reports its own version via get_version (OpenTTDAdminClient.get_bridge_version()), and
# an older one will not understand everything sent here. The bridge source lives in
# gamescript/AdminBridge/; tests/test_gamescript.py keeps this in step with the version declared
# there, so bumping one without the other fails in CI rather than at runtime.
GS_BRIDGE_VERSION = 4
class GameEventType(StrEnum):
"""Event kinds the AdminBridge GameScript can push over the Admin Network.
These are the values of the "event" field of each event dict, and what
OpenTTDAdminClient.subscribe_events() and wait_for_event() take. They are plain strings,
so a bare "vehicle_arrive" works everywhere a member does.
The first three are synthesised by the GameScript sampling game state on an interval,
because the engine raises no event for them; the rest are engine events forwarded as they
happen. VehicleLost, VehicleWaitingInDepot and VehicleUnprofitable have deliberately no
entry here: the engine only ever raises those for AI companies, never for a GameScript.
"""
# Polled: derived by diffing successive samples of the game state.
VehicleArrive = "vehicle_arrive"
VehicleDepart = "vehicle_depart"
CargoWaiting = "cargo_waiting"
# Forwarded straight from the engine's own GameScript events.
VehicleCrashed = "vehicle_crashed"
StationFirstVehicle = "station_first_vehicle"
IndustryOpen = "industry_open"
IndustryClose = "industry_close"
TownFounded = "town_founded"
CompanyNew = "company_new"
CompanyInTrouble = "company_in_trouble"
CompanyBankrupt = "company_bankrupt"
SubsidyOffer = "subsidy_offer"
SubsidyOfferExpired = "subsidy_offer_expired"
SubsidyAwarded = "subsidy_awarded"
SubsidyExpired = "subsidy_expired"
# Emitted by the bridge itself, never subscribed to: one poll produced more events than
# fit in the per-poll cap and `count` of them were discarded.
EventsDropped = "events_dropped"
class OpenTTDProtocol(TCPProtocol):
"""Low-level OpenTTD TCP protocol handler with encryption support."""
PacketType = PacketGameType
PACKET_END = PacketGameType.PACKET_END
def __init__(self, handler):
super().__init__(handler)
self.handler = handler
def receive_packet(self, source, data):
try:
if self.handler.encryption_enabled:
if not self.handler._recv_aead:
self.handler._recv_aead = monocypher.IncrementalAuthenticatedEncryption(self.handler._session_key_recv, self.handler._encryption_nonce)
_, rest = read_uint16(data)
payload = self.handler._recv_aead.unlock(bytes(rest[:16]), bytes(rest[16:]))
if payload is None:
raise SocketClosed("Decryption failed")
data = memoryview(struct.pack("<H", len(payload) + 2) + payload)
return super().receive_packet(source, data)
except Exception: # noqa: BLE001 - untrusted wire data: any decode failure must degrade to a no-op packet rather than kill the connection
return PacketGameType.ServerUnused, {}
async def send_packet(self, data):
if self.handler.encryption_enabled:
if not self.handler._send_aead:
self.handler._send_aead = monocypher.IncrementalAuthenticatedEncryption(self.handler._session_key_send, self.handler._encryption_nonce)
_, payload = read_uint16(memoryview(data))
mac, ciphertext = self.handler._send_aead.lock(payload.tobytes())
data = struct.pack("<H", 18 + len(ciphertext)) + mac + ciphertext
await self._can_write.wait()
if self.transport.is_closing():
raise SocketClosed
self.transport.write(data)
return len(data)
# --- Static Parsers ---
@staticmethod
def receive_ServerGameInfo(source, data):
from openttd_protocol.protocol.game import GameProtocol
return GameProtocol.receive_PACKET_SERVER_GAME_INFO(source, data)
@staticmethod
def receive_ServerError(source, data):
ec, _ = read_uint8(data)
return {"error_code": ec}
@staticmethod
def receive_ServerAuthenticationRequest(source, data):
at, rest = read_uint8(data)
return {"auth_type": at, "data": rest}
@staticmethod
def receive_ServerEnableEncryption(source, data): return {"data": data}
@staticmethod
def receive_ServerCheckNewGRFs(source, data): return {}
@staticmethod
def receive_ServerUnused(source, data): return {}
@staticmethod
def receive_ServerWelcome(source, data):
cid, _ = read_uint32(data)
return {"client_id": cid}
@staticmethod
def receive_ServerNeedCompanyPassword(source, data):
seed, data = read_uint32(data)
sid, _ = read_string(data)
return {"seed": seed, "server_id": sid}
@staticmethod
def receive_ServerFrame(source, data):
f, data = read_uint32(data)
_, data = read_uint32(data)
token = 0
if len(data) > 0:
if len(data) >= 13:
data = data[12:]
token, _ = read_uint8(data)
return {"frame": f, "token": token}
@staticmethod
def receive_ServerChat(source, data):
_, data = read_uint8(data)
cid, data = read_uint32(data)
_, data = read_uint8(data)
msg, _ = read_string(data)
return {"client_id": cid, "message": msg}
@staticmethod
def receive_ServerCompanyUpdate(source, data):
mask, _ = read_uint16(data)
return {"passworded_mask": mask}
@staticmethod
def receive_ServerMapDone(source, data): return {}
@staticmethod
def receive_ServerClientInfo(source, data): return {}
@staticmethod
def receive_ServerSync(source, data): return {}
@staticmethod
def receive_ServerClientJoined(source, data): return {}
@staticmethod
def receive_ServerMapBegin(source, data): return {}
@staticmethod
def receive_ServerMapSize(source, data): return {"size": 0}
@staticmethod
def receive_ServerMapData(source, data): return {"data": data}
@staticmethod
def receive_ServerConfigurationUpdate(source, data): return {}
@staticmethod
def receive_ServerExternalChat(source, data): return {}
@staticmethod
def receive_ServerCommand(source, data):
company, data = read_uint8(data)
cmd, data = read_uint16(data)
error_msg, data = read_uint16(data)
tile, data = read_uint32(data)
payload_len, data = read_uint16(data)
payload = data[:payload_len]
data = data[payload_len:]
callback, data = read_uint8(data)
callback_param = 0
if callback != 0:
callback_param, data = read_uint32(data)
frame, data = read_uint32(data)
my_cmd, _ = read_uint8(data)
return {
"company": company, "cmd": cmd, "error_msg": error_msg, "tile": tile,
"payload": payload, "callback": callback, "callback_param": callback_param,
"frame": frame, "my_cmd": bool(my_cmd)
}
@staticmethod
def receive_ServerFull(source, data): return {}
@staticmethod
def receive_ServerBanned(source, data): return {}
@staticmethod
def receive_ClientAck(source, data):
f, data = read_uint32(data)
t, _ = read_uint8(data)
return {"frame": f, "token": t}
@staticmethod
def receive_ClientIdentify(source, data): return {}
class OpenTTDAdminProtocol(OpenTTDProtocol):
"""Low-level OpenTTD Admin TCP protocol handler."""
PacketType = PacketAdminType
PACKET_END = PacketAdminType.PACKET_END
@staticmethod
def receive_ServerProtocol(source, data):
v, data = read_uint8(data)
updates = {}
while True:
has_more, data = read_uint8(data)
if not has_more:
break
ut, data = read_uint16(data)
freqs, data = read_uint16(data)
updates[ut] = freqs
return {"version": v, "updates": updates}
@staticmethod
def receive_ServerWelcome(source, data):
name, data = read_string(data)
ver, data = read_string(data)
dedi, data = read_uint8(data)
map_name, data = read_string(data)
seed, data = read_uint32(data)
land, data = read_uint8(data)
date, data = read_uint32(data)
width, data = read_uint16(data)
height, _ = read_uint16(data)
return {
"server_name": name, "openttd_version": ver, "dedicated": bool(dedi),
"map_name": map_name, "generation_seed": seed, "landscape": land,
"start_date": date, "map_width": width, "map_height": height
}
@staticmethod
def receive_ServerDate(source, data):
d, _ = read_uint32(data)
return {"date": d}
@staticmethod
def receive_ServerChat(source, data):
action, data = read_uint8(data)
dest_type, data = read_uint8(data)
cid, data = read_uint32(data)
msg, data = read_string(data)
money = 0
if len(data) >= 8:
import struct
money = struct.unpack("<Q", data[:8])[0]
return {"action": action, "dest_type": dest_type, "client_id": cid, "message": msg, "money": money}
@staticmethod
def receive_ServerConsole(source, data):
origin, data = read_string(data)
text, _ = read_string(data)
return {"origin": origin, "text": text}
@staticmethod
def receive_ServerRcon(source, data):
color, data = read_uint16(data)
text, _ = read_string(data)
return {"color": color, "text": text}
@staticmethod
def receive_ServerRconEnd(source, data):
cmd, _ = read_string(data)
return {"command": cmd}
@staticmethod
def receive_ServerAuthRequest(source, data):
at, rest = read_uint8(data)
return {"auth_type": at, "data": rest}
@staticmethod
def receive_ServerEnableEncryption(source, data): return {"data": data}
@staticmethod
def receive_ServerError(source, data):
ec, _ = read_uint8(data)
return {"error_code": ec}
@staticmethod
def receive_ServerFull(source, data): return {}
@staticmethod
def receive_ServerBanned(source, data): return {}
@staticmethod
def receive_ServerShutdown(source, data): return {}
@staticmethod
def receive_ServerNewGame(source, data): return {}
@staticmethod
def receive_ServerClientJoin(source, data):
cid, _ = read_uint32(data)
return {"client_id": cid}
@staticmethod
def receive_ServerClientInfo(source, data):
cid, data = read_uint32(data)
addr, data = read_string(data)
name, data = read_string(data)
lang, data = read_uint8(data)
date, data = read_uint32(data)
playas, _ = read_uint8(data)
return {
"client_id": cid, "network_address": addr, "name": name,
"language": lang, "join_date": date, "play_as": playas
}
@staticmethod
def receive_ServerClientUpdate(source, data):
cid, data = read_uint32(data)
name, data = read_string(data)
playas, _ = read_uint8(data)
return {"client_id": cid, "name": name, "play_as": playas}
@staticmethod
def receive_ServerClientQuit(source, data):
cid, _ = read_uint32(data)
return {"client_id": cid}
@staticmethod
def receive_ServerClientError(source, data):
cid, data = read_uint32(data)
error, _ = read_uint8(data)
return {"client_id": cid, "error_code": error}
@staticmethod
def receive_ServerCompanyNew(source, data):
cid, _ = read_uint8(data)
return {"company_id": cid}
@staticmethod
def receive_ServerCompanyInfo(source, data):
cid, data = read_uint8(data)
name, data = read_string(data)
manager, data = read_string(data)
color, data = read_uint8(data)
protected, data = read_uint8(data)
year, data = read_uint32(data)
is_ai, _ = read_uint8(data)
return {
"company_id": cid, "name": name, "manager_name": manager,
"color": color, "password_protected": bool(protected),
"inaugurated_year": year, "is_ai": bool(is_ai)
}
@staticmethod
def receive_ServerCompanyUpdate(source, data):
cid, data = read_uint8(data)
name, data = read_string(data)
manager, data = read_string(data)
color, data = read_uint8(data)
protected, data = read_uint8(data)
bankrupt, data = read_uint8(data)
s1, data = read_uint8(data)
s2, data = read_uint8(data)
s3, data = read_uint8(data)
s4, _ = read_uint8(data)
return {
"company_id": cid, "name": name, "manager_name": manager,
"color": color, "password_protected": bool(protected),
"quarters_of_bankruptcy": bankrupt, "share_owners": [s1, s2, s3, s4]
}
@staticmethod
def receive_ServerCompanyRemove(source, data):
cid, data = read_uint8(data)
reason, _ = read_uint8(data)
return {"company_id": cid, "reason": reason}
@staticmethod
def receive_ServerCompanyEconomy(source, data):
import struct
cid, data = read_uint8(data)
money = struct.unpack("<Q", data[:8])[0]
data = data[8:]
loan = struct.unpack("<Q", data[:8])[0]
data = data[8:]
income = struct.unpack("<q", data[:8])[0]
data = data[8:]
delivered, data = read_uint16(data)
val_lq = struct.unpack("<Q", data[:8])[0]
data = data[8:]
perf_lq, data = read_uint16(data)
del_lq, data = read_uint16(data)
val_pq = struct.unpack("<Q", data[:8])[0]
data = data[8:]
perf_pq, data = read_uint16(data)
del_pq, _ = read_uint16(data)
return {
"company_id": cid, "money": money, "loan": loan, "income": income,
"delivered_cargo": delivered, "value_last_quarter": val_lq,
"performance_last_quarter": perf_lq, "delivered_cargo_last_quarter": del_lq,
"value_previous_quarter": val_pq, "performance_previous_quarter": perf_pq,
"delivered_cargo_previous_quarter": del_pq
}
@staticmethod
def receive_ServerCompanyStats(source, data):
cid, data = read_uint8(data)
trains, data = read_uint16(data)
lorries, data = read_uint16(data)
buses, data = read_uint16(data)
planes, data = read_uint16(data)
ships, data = read_uint16(data)
t_stations, data = read_uint16(data)
l_stations, data = read_uint16(data)
b_stops, data = read_uint16(data)
airports, data = read_uint16(data)
harbours, _ = read_uint16(data)
return {
"company_id": cid,
"vehicles": {"trains": trains, "lorries": lorries, "buses": buses, "planes": planes, "ships": ships},
"stations": {"train": t_stations, "lorry": l_stations, "bus": b_stops, "airport": airports, "harbour": harbours}
}
@staticmethod
def receive_ServerGamescript(source, data):
json_str, _ = read_string(data)
import json
try:
return {"data": json.loads(json_str)}
except json.JSONDecodeError:
return {"raw_data": json_str}
@staticmethod
def receive_ServerPong(source, data):
payload, _ = read_uint32(data)
return {"payload": payload}