Files
K11MCH1andKurt Himebauch f16b023f0d fix(ubisoft): R2 games get a session matching the subsystems they ask for (#2450)
uplay_r2.dll speaks the same UplayDll.proto as uplay_r1.dll, but its InitReq
names the subsystems the game uses (fields 4 to 11) and its ApiContext only
creates objects for those. It copies gameInstall and storage into their
objects without checking for them, so the gameInstall droiddeck-upc always
sent crashed Prince of Persia: The Lost Crown (6145), which asks for overlay,
product and store only: an access violation reading 0x68 in
uplay_r264.dll+0xaca2 two seconds after the session.

- When the request names subsystems, gameInstall (14) is sent only with
  subSystemInstall and storage (17) only with subSystemStorage, and an empty
  multiplayerInit (20) is added. Requests that name none keep the old session.
- streamingReq (27) is answered: the streaming type is None, other streaming
  queries are not found.
- The log records the subsystems each init asked for.

Co-authored-by: Kurt Himebauch <136133082+xXJSONDeruloXx@users.noreply.github.com>
2026-11-11 10:34:06 -05:00

9.2 KiB

Ubisoft launch without Ubisoft Connect

A Ubisoft game never holds its own ticket. Its DRM loader opens Ubisoft's API DLL from the Connect folder, and that DLL asks the running launcher for the session over local named pipes. DroidDeck answers those pipes with droiddeck-upc.exe, a small Windows program that runs in the game's prefix. The game and every Ubisoft DLL stay unmodified, and there is no Connect client, CEF or background service. The session the game receives is real: its ticket comes from Ubisoft's ownership service for the signed-in account.

This file is the specification tools/ubisoft-launcher was written from. The facts come from the protobuf descriptors embedded in Ubisoft's own uplay_r1.dll (proto_uplaydll/UplayDll.proto) and from the public notes in Foxtrot47/Ubisoft-Connect-RE (docs/06-launch.md, docs/10-denuvo.md). No code was taken from either.

Pieces

Piece Where Job
Ubisoft runtime C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher\ in the shared prefix Ubisoft's own uplay_r1(64).dll, uplay_aux_r1(64).dll, uplay_r2(64).dll, ubiorbitapi_r2(64).dll, UbisoftGameLauncher(64).exe, the starter's imports (discord-rpc.x86/x64.dll, steam_api(64).dll) and overlay(64).dll. droiddeck-store-launch extracts exactly these 16 files with 7z from the official UbisoftConnectInstaller.exe, then deletes the installer
Registry HKLM\Software\[Wow6432Node\]Ubisoft\Launcher InstallDir points at the runtime folder in both views; Installs\<productId>\InstallDir points at the game, with forward slashes and a trailing slash, as Connect writes it
Shared prefix compatdata/2929927072 Every Ubisoft game runs here (UbisoftConnect.launchOptions sets STEAM_COMPAT_DATA_PATH), so the runtime is extracted once
Launch file <game>/.droiddeck-ubisoft.json Written by droiddeck-store-launch before every launch from the app's ubisoft-launch answer: the account, the owned product ids, a fresh PC ticket, the entitlement's application id and the save folder. Removed first, so a failed refresh falls back to starting the game directly
Launcher <game>/.droiddeck-launch.bat Runs Z:\usr\local\lib\droiddeck-ubisoft\droiddeck-upc.exe <launch file> when both exist
Tickets app, Rust ubisoft/service.rs Demux ownership_service: initialize (owned products), then GetUplayPCTicketReq (field 14) answered in field 13 {1: success, 2: ticket}

Pipes

All pipes are \\.\pipe\terminal_<session>_<name>, where <session> is ProcessIdToSessionId(GetCurrentProcessId()) (1 under Wine). They are byte-mode duplex pipes with unlimited instances, created before the game starts. Every message is a 4-byte big-endian length followed by a proto2 message, except on uplay_service_ipc_pipe_.

Pipe Client Exchange
game_start_ipc_pipe_ UbisoftGameLauncher.exe game_starter.Upstream{1:{1:{1: build, 2: product, 10: exe, 11: arguments, ...}}} → Downstream{2:{1:{1:0 (overlay off), 2:0, 3: <root>/ + "/" + <exe under root>, 4: <root>/, 8:3, 9:{1:{1,113,0,1,0} 1:{3,123,0,0,0}}}}}
uplay_api_process_ipc_pipe_ game Req.initProcessReq{1: product, 2: game pid, 5: env set} → Rsp.initProcessRsp(13){1:1, 3:0 (overlay off), 4:3, 6:0}. Kept open. Answering it is what releases the starter (below). Far Cry 3 Blood Dragon sends only {2: pid, 5:1}; a missing pid is taken from the pipe's client process
uplay_ipc_pipe_ game (uplay_r1.dll, uplay_r2.dll) Req.initReq(1) → Rsp.initRsp(1), answered every time it is asked. Req.installerReq(13) with initInstallerReq → Rsp.installerRsp(10){1:{1:1, 2:"", 3: language}}. Req.userReq(11).getCredentialsReq(1){1: id} → Rsp.userRsp(8).getCredentialsRsp(1){1: id, 2: username, 3: "" (password), 4: userId, 5: email}. Req.streamingReq(27) → Rsp.streamingRsp(20){1: id, 2:1, 4:{1:0}} for the streaming type (not streamed), {1: id, 2:4} for any other streaming query
uplay_aux_ipc_pipe_ uplay_aux_r1(64).dll (Denuvo) {1: rid, 2: init} → {1: rid, 2:{1:1, 2: pid, 3:3367, 3:3368, 3:3962}}; {1: rid, 3:{2:{2: challenge}}} → {1: rid, 3:{2:{2:1, 3:0, 4: game token, 5:""}}}
uplay_service_ipc_pipe_ Ubisoft helpers Server sends {3:{1:1, 3:{1: <hwscore path>}}} once, then only reads, unframed
orbit_ipc_pipe_ game (ubiorbitapi_r2.dll) mg.protocol.orbitdll from the DLL's own proto_orbitdll/OrbitDll.proto. Req{1: id, 12: init{1: product}} → Rsp{1: id, 12:{1: save folder, 2:1}}; getLoginDetails(2) → {1: username, 2:"", 3:""}; getOsi(3){1: sub} → {2:1} (failed, no online-services pipe)
upc_api_process_ipc_pipe_standard, uplay_protocol_ipc_pipe_, uplay_overlay_ipc_pipe_, uplay_crash_reporter_ipc_pipe_ — Held open, never answered

The session (InitRsp)

Field Value
1 result 1 (InitResult_Success)
2 account {1: userId, 2: username, 3: nameOnPlatform, 4: email, 5: "" (password), 6: country}
3 connected 1
4 gameUplayId the product
5 uplayIds every owned product whose ownership entry is owned, of type 0 or 1, in state 0 or 3
6 gameCdKeys {1: product, 2: ""}
7 isInOfflineMode 0
8 upcTicket the PC ticket from GetUplayPCTicket, never the Denuvo token
11, 12, 15, 16, 18, 19, 21, 23 the values a real launch carries ({1:0}, 0, overlay {1:0, 2:3}, hardware score {6211, 22395, 1.0f}, empty, {1:1, 2:1}, {2:1}, empty)
14 gameInstall {1:1, 2: installed chunks, 3: language}
17 storage {1: "C:/users/steamuser/Saved Games/Ubisoft/<userId>/<product>/"}; the game appends file names directly, so the trailing slash matters
22 ubiServices {1: applicationId} from the account's entitlements, left out when unknown

R2 titles

uplay_r2.dll speaks the same mg.protocol.uplaydll messages (its embedded UplayDll.proto is identical to uplay_r1.dll's), but its InitReq names the subsystems the game uses: fields 4 to 11 (friend, overlay, product, storage, install, multiplayer, store, streaming). Its ApiContext creates one object per requested subsystem and copies the session into them. Friends, overlay, game session, store and crossboot are checked for a missing object first; install and storage are not. A gameInstall sent to a game that did not ask for install is copied into a null object: Prince of Persia: The Lost Crown (6145) asks for overlay, product and store only, and crashed reading 0x68 in uplay_r264.dll+0xaca2 two seconds after the session arrived.

So when the request names subsystems, 14 is sent only with subSystemInstall (8), 17 only with subSystemStorage (7), and an empty multiplayerInit (20) is added, which uplay_r2.dll asks for even when empty. A request that names none gets the session above unchanged. The Lost Crown also opens a second context that asks for every subsystem, and it gets the full session.

The overlay is reported off in all three places. uplay_r1.dll still loads overlay.dll from the runtime folder right after the session arrives, whatever the session says; without that file it gives up with UplayAPI [ERROR]: Startup failed: cannot load uplay library (Assassin's Creed Chronicles: China then sits on a black screen and aborts with code 3 after about 160 s), so the runtime includes it.

Orbit titles

Older titles such as Far Cry 3 Blood Dragon (205) load ubiorbitapi_r2.dll next to uplay_r1.dll and ask orbit_ipc_pipe_ for init before anything else; unanswered, the game waits forever on a black screen. The DLL keeps savegames itself as *.save files in the folder init returns, the same save folder as field 17 above.

Start sequence

  1. droiddeck-upc.exe creates the pipes and an auto-reset event marked inheritable, then starts the game's own exe with handle inheritance, in the install folder, with no extra arguments.
  2. The exe sees it was not started by Connect and starts UbisoftGameLauncher.exe -gamelauncher_wait_handle <event> -upc_uplay_id <product> ... (it exits with code 3; that is normal).
  3. The starter asks game_start and starts the real game from the reply.
  4. The game announces itself on uplay_api_process; the answer sets the event, which lets the starter exit. Without it the starter times out and its job object ends the game after about 15 seconds.
  5. uplay_r1.dll asks uplay_ipc for the session.
  6. droiddeck-upc.exe waits for the announced process, allows 15 s for a restart, then exits with the game's code so Steam sees the game end.

A log of every exchange is written to ~/.cache/droiddeck/ubisoft/upc-<product>.log in the guest.

Denuvo

For protected titles the aux pipe carries the activation challenge. droiddeck-upc.exe writes it to ~/.cache/droiddeck/ubisoft/bridge-<product>/denuvo-<rid>.req and waits 90 s for .rsp. Answering it needs denuvo_service with an ownership token (OwnershipTokenReq, field 28) and is the next step; titles without Denuvo never open the aux pipe.

Not covered yet

  • R2 titles other than The Lost Crown, and R2 requests beyond the session, credentials, product list and streaming type.
  • Orbit's online-services pipe (getOsi is declined) and Orbit titles other than Far Cry 3 Blood Dragon.
  • Achievements, friends, overlay, cloud saves.