IPC Commands

IPC Commands

This page documents the IPC commands used by ryu_ldn_nx.

Standard LDN Commands

These are the standard Nintendo LDN IPC commands that ryu_ldn_nx intercepts:

Service: ldn:u

Cmd	Name	Description
0	CreateUserLocalCommunicationService	Creates a communication session

ICommunicationInterface

Cmd	Name	Description
0	GetState	Get current LDN state
100	AttachStateChangeEvent	Get event handle for state changes
200	GetNetworkInfo	Get current network information
201	GetIpv4Address	Get local IPv4 address
202	GetDisconnectReason	Get reason for last disconnect
203	GetSecurityParameter	Get security configuration
204	GetNetworkConfig	Get network configuration
300	OpenAccessPoint	Open as network host
301	CloseAccessPoint	Close host mode
302	CreateNetwork	Create a new network
303	CreateNetworkPrivate	Create private network
304	DestroyNetwork	Destroy current network
400	OpenStation	Open as client
401	CloseStation	Close client mode
402	Connect	Connect to a network
403	ConnectPrivate	Connect to private network
404	Disconnect	Disconnect from network
500	SetAdvertiseData	Set advertisement data
600	Scan	Scan for networks
601	ScanPrivate	Scan for private networks

Custom Config Commands

ryu_ldn_nx adds custom IPC commands for overlay communication. These are obtained via command 65000 on the MITM service.

LdnConfigService

Cmd	Name	Parameters	Returns	Description
65001	GetVersion	-	char[32]	Sysmodule version string
65002	GetConnectionStatus	-	u32	Server connection state
65003	GetLdnState	-	u32	Current LDN state
65004	GetSessionInfo	-	SessionInfo	Current session information
65005	GetServerAddress	-	ServerAddress	Configured server address
65006	SetServerAddress	ServerAddress	-	Change server address
65007	GetDebugEnabled	-	u32	Debug logging state
65008	SetDebugEnabled	u32	-	Enable/disable debug
65009	ForceReconnect	-	-	Force server reconnection
65010	GetLastRtt	-	u32	Last RTT in milliseconds

Data Structures

ConnectionStatus (enum u32)

Value	Name	Description
0	Disconnected	Not connected to server
1	Connecting	Connection in progress
2	Connected	TCP connected, handshake pending
3	Ready	Fully connected and operational
4	Error	Connection error occurred

LdnState (enum u32)

Value	Name	Description
0	None	Not initialized
1	Initialized	Service initialized
2	AccessPoint	Host mode opened
3	AccessPointCreated	Network created
4	Station	Client mode opened
5	StationConnected	Connected to network
6	Error	Error state

SessionInfo (struct, 72 bytes)

Offset	Type	Name	Description
0x00	u8	node_count	Players in session
0x01	u8	node_count_max	Maximum players
0x02	u8	local_node_id	Our node ID
0x03	u8	is_host	1 if hosting
0x04	u32	session_duration_ms	Session duration
0x08	char[64]	game_name	Game name

ServerAddress (struct, 68 bytes)

Offset	Type	Name	Description
0x00	char[64]	host	Server hostname
0x40	u16	port	Server port
0x42	u16	padding	Reserved

Usage Example (C)

// Get config service from ldn:u MITM
Service ldnService;
smGetService(&ldnService, "ldn:u");

RyuLdnConfigService configService;
serviceDispatch(&ldnService, 65000,
    .out_num_objects = 1,
    .out_objects = &configService.s,
);

// Get version
char version[32];
serviceDispatchOut(&configService.s, 65001, version);
printf("Version: %s\n", version);

// Get connection status
u32 status;
serviceDispatchOut(&configService.s, 65002, &status);
printf("Status: %u\n", status);

// Force reconnect
serviceDispatch(&configService.s, 65009);