Networking And Public Variables

Networking And Public Variables

Arma 2 OA networking here is built around public variables, public-variable event handlers and wrapper functions that dispatch named PVF commands.

Central PVF Registration

Common/Init/Init_PublicVariables.sqf creates two command lists:

Server PVF commands:

• RequestVehicleLock
• RequestOnUnitKilled
• RequestChangeScore
• RequestCommanderVote
• RequestNewCommander
• RequestStructure
• RequestDefense
• RequestJoin
• RequestMHQRepair
• RequestSpecial
• RequestTeamUpdate
• RequestUpgrade
• RequestAutoWallConstructinChange

Client PVF commands:

• AllCampsCaptured
• AwardBounty
• AwardBountyPlayer
• CampCaptured
• ChangeScore
• HandleSpecial
• LocalizeMessage
• SetTask
• SetVehicleLock
• TownCaptured
• SetMHQLock
• Available
• RequestBaseArea
• NukeIncoming

Each command is compiled into either SRVFNC... or CLTFNC..., and WFBE_PVF_<Command> receives an event handler that passes payloads to Server_HandlePVF or Client_HandlePVF.

Network Helper Layer

• Common_SendToServer: sends a server PVF; uses optimized publicVariableServer outside vanilla mode.
• Common_SendToClients: broadcasts client PVF to all clients.
• Common_SendToClient: targets one client where supported.

These wrappers are preferred over hand-coded public variable dispatch for new features.

Direct Public Variables

Some systems use explicit public-variable channels outside the generic PVF list:

• Supply mission: WFBE_Client_PV_IsSupplyMissionActiveInTown, WFBE_Client_PV_SupplyMissionStarted, WFBE_Server_PV_IsSupplyMissionActiveInTown, WFBE_Server_PV_SupplyMissionCompleted, WFBE_Server_PV_SupplyMissionCompletedMessage.
• Anti-stack join checks: WFBE_CLIENT_HAS_CONNECTED_AT_LAUNCH, WFBE_P_HAS_CONNECTED_AT_LAUNCH_ACK, WFBE_C_PLAYER_OBJECT.
• Day/night: WFBE_DAYNIGHT_DATE.
• Server FPS/HUD: SERVER_FPS_GUI, WFBE_VAR_SERVER_FPS.
• AFK kick: AFKthresholdExceededName and kickAFK; kickAFK is intentionally caught by BattlEye filters because serverCommand is unavailable.
• Markers/messages: MARKER_CREATION, SEND_MESSAGE, ICBM and radiation variables.

Safety Notes

• Keep payloads small and structured; Arma 2 public-variable traffic can be expensive.
• Prefer server authority for state changes. Client scripts should request, not mutate, team/base/economy state directly.
• When adding a PVF command, update both the registration list and the target Client/PVFunctions or Server/PVFunctions file.
• Hosted-server paths often call the handler locally in addition to broadcasting. Preserve those branches when modernizing code.

PVF Dispatch Internals

Claude independently deep-read the dispatch path and confirmed these runtime details. Paths are relative to Missions/[55-2hc]warfarev2_073v48co.chernarus/.

One PV Variable Per Command

Common/Init/Init_PublicVariables.sqf:43-51 creates one public-variable name per command, such as WFBE_PVF_RequestJoin and WFBE_PVF_TownCaptured, each with its own addPublicVariableEventHandler. This is not one numeric multiplexed protocol channel. Client handlers register under if (!isServer || local player); server handlers register under if (isServer).

Client-Side Index-0 Routing

Client/Functions/Client_HandlePVF.sqf uses payload element 0 as the destination filter:

Element 0	Client behavior
nil	Run on all clients.
SIDE	Run only if sideJoined == destination.
STRING	Run only if getPlayerUID player == destination.

The actual function name comes from element 1 (CLTFNC<Command>) and is executed with _parameters Spawn (Call Compile _script). Server/Functions/Server_HandlePVF.sqf is simpler: it resolves SRVFNC<Command> and spawns it with no destination filtering.

Wrapper To Engine Primitive Map

Wrapper	Direction	Engine primitive	Destination handling
Common_SendToServer / optimized variant	client -> server	publicVariable or publicVariableServer	Server PVF receives command payload.
Common_SendToClients	server -> clients	publicVariable	Payload element 0 is nil, side, or UID.
Common_SendToClient	server -> one client	publicVariableClient to owner _player	Player object is rewritten to UID for the client filter.

Second-Level Multiplexers

Some registered commands are broad routers:

• Client/PVFunctions/HandleSpecial.sqf switches over tags such as join-answer, attack-wave, commander-vote and endgame.
• Client/PVFunctions/LocalizeMessage.sqf switches over message keys such as Teamkill, FundsTransfer and AttackModeActivated.

When tracing one feature, grep the string tag as well as the PVF command name.

Gotchas

• UID-targeted SendToClients still broadcasts to every client and lets non-matching clients discard locally. Use SendToClient for true unicast when possible.
• PVF handlers use Spawn, so rapid messages that mutate shared state have no strict ordering guarantee.
• Both dispatchers use Call Compile on the generated function-name string per dispatch. Keep command names controlled and avoid turning hot paths into chatty PVF streams.
• Some bare PV channels are copied per side, such as wfbe_supply_temp_west and wfbe_supply_temp_east; there is no resistance-side handler in that path.

Security: the Call Compile trust boundary

Server_HandlePVF.sqf / Client_HandlePVF.sqf run Call Compile on the function-name string taken from the value a remote machine broadcast (select 0 / select 1), with no check that it names a registered command — and the shipped BattlEyeFilter/publicvariable.txt only carries the kickAFK feature rule, not a security filter. Validate the command string against the known SRVFNC*/CLTFNC* set before compiling, and add a real BattlEye PV filter (restrictive default + whitelist of WFBE_PVF_* and the direct channels, keeping kickAFK). Full analysis and remediation playbook: Deep-review findings DR-1.

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