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NWM Services

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Revision as of 17:48, 13 April 2016 by Yellows8 (talk | contribs) (→‎Network structure)


These NWM services are used for local-WLAN communications, NWM module handles regular wifi APs as well. These services are used for creating/connecting to networks, and for sending/receiving data over the network etc. NWM module uses the wifi SDIO hardware via the IO registers for this.

NWM local-WLAN service "nwm::UDS"

Command Header Available since system version Description
0x00010442 Initialize Deprecated. Appears to be handled about the same way as NWMUDS:InitializeWithVersion, except this uses version=0x100 internally instead of loading it from the command request.
0x00020000 Scrap Not used by sub-wars. This sets a state value to 0x2 then signals an event. This is probably some sort of shutdown command since this state write will result in all UDS commands returning an error if used afterwards.
0x00030000 Shutdown
0x00040402 CreateNetwork Deprecated. Only used by very old titles.
0x00050040 EjectClient
0x00060000 EjectSpectator
0x00070080 UpdateNetworkAttribute
0x00080000 DestroyNetwork
0x00090442 ConnectNetwork Deprecated. Only used by very old titles.
0x000A0000 DisconnectNetwork
0x000B0000 GetConnectionStatus
0x000C0000 This writes two output u8 values to cmdreply[2] +0/+1. Not used by sub-wars.
0x000D0040 GetNodeInformation
0x000E0006 Identical to DecryptBeaconData. Deprecated, only used by old titles.
0x000F0404 RecvBeaconBroadcastData
0x00100042 SetApplicationData
0x00110040 GetApplicationData
0x00120100 Bind
0x00130040 Unbind
0x001400C0 PullPacket
0x00150080 SetMaxSendDelay(u64 unk) Not used by sub-wars.
0x00160040 (u8 inputval) Unknown. Not used by sub-wars.
0x00170182 SendTo
0x00180040 (u16 inputval) Unknown. Not used by sub-wars.
0x00190040 (u32 inputval) Unknown. Not used by sub-wars.
0x001A0000 GetChannel
0x001B0302 InitializeWithVersion
0x001C0040 (u8 inputval) Unknown. Not used by sub-wars.
0x001D0044 Unknown, >2.0.0-2 BeginHostingNetwork This is a replacement for the original network-creation command.
0x001E0084 Unknown, >2.0.0-2 ConnectToNetwork This is a replacement for the original network-connection command.
0x001F0006 Unknown, >2.0.0-2 DecryptBeaconData
0x00200040 Unknown, >2.0.0-2 Flush (u8 data_frame_index) Unknown. Not used by sub-wars.
0x00210080 Unknown, >2.0.0-2 SetProbeResponseParam
0x00220402 Unknown, >2.0.0-2 ScanOnConnection
0x00230000 Unknown, >2.0.0-2 This writes an output u16 value to cmdreply[2]. Unknown. Not used by sub-wars.

PullPacket is used for receiving data over the network and SendTo is for sending data over the network.

NWM infrastructure service "nwm::INF"

Command Header Description
0x000603C4 RecvBeaconBroadcastData
0x00070742 ConnectToEncryptedAP
0x0008.... ConnectToAP

NWM socket service "nwm::SOC"

NWM service "nwm::SAP"

NWM local-WLAN StreetPass service "nwm::CEC"

Command Header Description
0x00060002 Unknown, called by CECD module, cmdbuf[2] takes an event handle.
0x000D0082 SendProbeRequest

NWM service "nwm::EXT"

Command Header Available since system version Description
0x0001.... <=2.0.0-2 ?
0x0002.... <=2.0.0-2 ?
0x0003.... <=2.0.0-2 ?
0x0004.... <=2.0.0-2 ?
0x0005.... <=2.0.0-2 ?
0x0006.... <=2.0.0-2 ?
0x00070000 <=2.0.0-2 This copies 0x1C-bytes from NWM-module state to the data starting at cmdreply[2].
0x00080040 <=2.0.0-2 ControlWirelessEnabled
0x0009.... <=2.0.0-2 ?

NWM service "nwm::TST"

BeaconDataReply Structure

Offset Size Description
0x0 0x4 Max output size, from the command request.
0x4 0x4 Total amount of output data written relative to struct+0. 0xC when there's no entries.
0x8 0x4 Total entries, 0 for none.
0xC <Rest of the structure> Beacon entries.

Beacon entry:

Offset Size Description
0x0 0x4 Size of this entire entry. The next entry starts at curentry_startoffset+curentry_size.
0x4 0x1 ?
0x5 0x1 AP wifi channel.
0x6 0x1 ?
0x7 0x1 ?
0x8 0x6 AP MAC address.
0xE 0x6 ?
0x14 0x4 ?
0x18 0x4 Value 0x1C(size of this header and/or offset to the actual beacon data).
0x1C Entry_size - 0x1C The actual beacon data is located here, starting at the 802.11 management frame header.

This section describes the structure returned by NWMINF:RecvBeaconBroadcastData and NWMUDS:RecvBeaconBroadcastData.

ScanInputStruct

Index Word Description
0 Two unknown u16s.
1 Two unknown u16s.
2-3 Host MAC address. The 6-bytes located here are normally all 0xFF, for all hosts. Otherwise when not set to broadcast-MAC, the command will only return info for the specified host MAC address.
4-12 Uninitialized for UDS.

This section describes the 0x34-byte input structure used by NWMINF:RecvBeaconBroadcastData and NWMUDS:RecvBeaconBroadcastData.

Local-WLAN

UDS is used for 3DS<>3DS local-WLAN communications, and for 3DS<>Wii U communications. The latter is mainly only used for multi-player in games.

All UDS local-WLAN communications have the CCMP key for data encryption generated via NWM module. The CCMP key passed to nwm::CEC commands(stored in a 0x44-byte input structure) for StreetPass is generated by the CECD module. The input data used with EncryptDecryptAes with keytype1 is a MD5 hash over the input passphrase. This input passphrase is fixed for Download Play, it's unique per local-WLAN application. The CTR is a MD5 hash over the below 0x10-byte structure. The output from encrypting that data with AES-CTR is the final CCMP key. This passphrase is a raw input buffer: while the passphrase specified by user-processes is normally a string with the NUL-terminator included, it can be anything(like the WirelessRebootPassphrase for example).

The maximum number of nodes(including the host) which can be on an UDS network is 16.

NodeID

There are two types of client connections: regular Client, and Spectator. The latter never sends any 802.11 frame at all to the host, hence nothing actually connected to the network(including the host) can know about any spectators. Once a spectator is "connected" to a network, it can only receive broadcasted data, no sending.

DLP-client connects to the network as a spectator during DLP scanning to get various metadata including icon data.

NetworkNodeID

This is the network u16 ID for each device on the UDS network. NodeID 0xFFFF is a broadcast alias. 0x1 is for the host, the 0x2 for the first client, 0x3 for the second client, and so on.

The spectator doesn't have a NetworkNodeID, since it can't send any data.

NetworkNodeIDs for clients do not change when any clients disconnect, likewise for the encrypted node-listing stored in the wifi beacons. When a client disconnects, the corresponding NetworkNodeID bit in the node_bitmask is cleared. When a client is connecting, the client is assigned the NetworkNodeID with the lowest corresponding clear-bit in the node_bitmask, then that bit is set.

BindNodeID

This u32 is an ID only used on the local device. How many devices are on the network or which device this system is does not affect this ID.

The spectator uses BindNodeID 0x1. DLP uses BindNodeID 0x3 when connecting as an actual client. Hence, it seems BindNodeID bit0 is spectator-related. All normal nodes(host/client) start with BindNodeID 0x2. When connecting to a network again(and probably with network creation) without reinitializing NWMUDS, official user processes increase the used BindNodeID by 0x2.

BindNodeID value 0x0 is invalid. The maximum number of BindNodeIDs which can be open at the same time is 16.

Application data transfer

The protocol used for sending/receiving data over the network with UDS by official applications is PRUDP(in some cases at least). Mario Kart 7 uses PRUDP here. Triforce Heroes uses plaintext for whatever protocol it uses for UDS.

The UDS version of PRUDP is different from the normal UDP version it appears(no afa1/a1af data for example).

Data frames

Data is transferred over the network using NWMUDS:PullPacket/NWMUDS:SendTo. That data is transferred using 802.11 data frames using CCMP encryption. The encrypted data contained in the frame starts with the 0x10-byte LLC header, then the 0xE-byte NWM header, followed by the actual application data from the previously mentioned commands. When NWMUDS:SendTo was used with dst_NodeID = broadcast, the data frame is sent to the 802.11 broadcast MAC address. Otherwise with a specific NodeID, the data frame is sent to the actual MAC address for that device.

Official application data is normally stored here as big-endian.

Structure used for generating the CTR for CCMP key generation

Offset Size Description
0x0 0x4 Local-WLAN communication ID, normally this is: (user_process uniqueID << 8) | val. Where val is 0x10 on retail(configmem UNITINFO bit0 set), 0x90 for devunit. For Download Play, this is always 0x2810 on retail(0x2890 on devunit).
0x4 0x4 u32 networkID, randomly-generated when creating the network. The network SSID used when a client connects to the network is sprintf(out, "%08X", networkID).
0x8 0x6 Host MAC address.
0xE 0x2 ID, for Download Play this is 0x55.

This data is stored as little-endian.

CTR used for beacon tags crypto

Offset Size Description
0x0 0x6 Host MAC address
0x6 0x4 wlancommID
0xA 0x1 This ID is also stored at offset 0xE in the CTR-generation structure.
0xB 0x1 Padding, value zero.
0xC 0x4 This is the u32 from offset 0x18 in the network-struct.

This data is stored as little-endian. All data here is all-zero except for the MAC address, when the u8 at offset 0x8 in the network-struct is 0.

Network structure

Offset Size Description
0x0 0x6 This is the MAC address of the host. This is used for when connecting to the network.
0x6 0x1 This is actually written as an u16 without byte-swapping. This is the network wifi channel. When connecting this is normally non-zero. When hosting, this can be 0 to automatically select a channel, or: 1, 6, or 11.
0x7 0x1 Padding
0x8 0x1 Initialized flag. Must be non-zero otherwise NWM-module will use value 0x0 for most/all(?) fields in this structure when reading these fields.
0xC 0x3 This is the OUI value for use with the beacon tags. Normally this is 001F32.
0xF 0x1 OUI type (21/0x15)
0x10 0x4 wlancommID
0x14 0x1 This ID is also stored at offset 0xE in the CTR-generation structure.
0x15 0x1 Some sort of counter for how many times this network was connected to?
0x16 0x2 This network attributes u16 bitmask can be written via NWMUDS:UpdateNetworkAttribute.

Bitmasks:

  • 0x1: When set, spectators are not allowed to connect(see here). Checked by official user-processes before using NWMUDS:ConnectToNetwork, when connecting as a Spectator. Must be clear otherwise that code returns error 0xE10113EA. If the initialized_flag at offset 0x8 is zero, this code handles it the same way as if this bit was set. The latest NWM-module handles checking this bit itself however.
  • 0x2: When set, new regular-clients are not allowed to connect.
  • 0x4: Unknown, has no affect on new clients/spectators connecting. Official software has an option for setting this bit via an input flag from the same code using bitmask 0x2. Official software always clears bitmask 0x6 when unblocking new connections.
0x18 0x4 u32 networkID, see above.
0x1C 0x1 Total number of currently connected nodes, including the host.
0x1D 0x1 Maximum number of nodes, including the host. This also is the total number of entries stored under the array in the encrypted beacon data.
0x1E 0x1 ?
0x1F 0x1 ?
0x3F 0x1 Size of appdata.
0x40 0xC8 Appdata(Application data), if any. Size of the appdata is specified via the u8 at offset 0x3F. This data is not used when the size-field is zero.

This 0x108-byte structure is used for NWMUDS:BeginHostingNetwork, NWMUDS:ConnectToNetwork, etc. This data is stored as big-endian.

NodeInfo structure

Offset Size Description
0x0 0x8 u64 ID, this is the UDS version of the FriendCodeSeed. This is loaded from BlkID 0x00090000 in the system-config via CfgS:GetConfigInfoBlk2.
0x8 0x14 The first 0x18-bytes from BlkID 0x000A0000 in the system-config loaded via CfgS:GetConfigInfoBlk2 is written here by user-processes. However, the data at +0x14(absolute offset 0x1C) is written by NWM-module later.
0x1C 0x2 u16, unknown. Set to 0x0 with the output from NWMUDS:DecryptBeaconData.
0x1E 0x1 u8 flag, unknown. Originates from the u16 bitmask in the beacon node-list header. This flag is normally 0 since that bitmask is normally 0?
0x1F 0x1 Padding?
0x20 0x2 u16 NetworkNodeID
0x22 0x6 Normally zero?

The first 0x20-bytes are written by the user-process before using this structure with NWMUDS:InitializeWithVersion. The data starting at offset 0x8 is only initialized by NWM-module.

UDS Beacons

The UDS host broadcasts a beacon containing at least two Nintendo-vendor tags(tag number 0xDD, see above for the OUI), normally the data stored in these tags are static. The second tag contains the big-endian u32 networkID, used by the clients when connecting to the host and for the above CCMP key generation. The Nintendo-vendor tag(s) following the first two are unique to the process using UDS, these tags are used for broadcasting metadata regarding the host.

A tool for these beacons is available here: [1]

UDS Beacon Tags

The following is the structure of each tag, starting at the OUI. The order of the tags is the same as listed below. All data stored under these tags are stored as big-endian.

OUI Type 20

Offset Size Description
0x0 0x3 OUI, see above.
0x3 0x1 OUI type (20/0x14)
0x4 0x3 Sample data: 0a 00 00

Normally the size of this tag(from the tag size field) is 0x07.

OUI Type 21

Offset Size Description
0x0 0x1F This is the network structure starting at offset 0xC, with the first 0x1F-bytes from there.
0x1F 0x14 SHA1 hash. When doing the hashing, this hash is cleared to zero. The hash data starts at offset 0x0(OUI), and the size is 0x34 + <value of the u8 at offset 0x33>.
0x33 0x1 Size of appdata. Normally zero. When non-zero this appdata is located at offset 0x34.

Normally the size of this tag(from the tag size field) is 0x34, not including appdata.

OUI Type 24

Offset Size Description
0x0 0x3 OUI, see above.
0x3 0x1 OUI type (24/0x18)
0x4 See below Encrypted data

This is the tag0 used with NWMUDS:DecryptBeaconData. The size of data stored under this tag has a maximum size of 0xFA-bytes, however normally the size is smaller than that. Additional encrypted data, if any, is stored under the below tag1.

OUI Type 25

Offset Size Description
0x0 0x3 OUI, see above.
0x3 0x1 OUI type (25/0x19)
0x4 See above Encrypted data

When this exists in the beacon, this is the tag1 used with NWMUDS:DecryptBeaconData. The data stored here is the 0xFA-bytes following the previous encrypted data in tag0, for more space for storing the encrypted data.


Encrypted beacon data

The following structure is for the plaintext version of the encrypted data, stored as big-endian.

This data is encrypted with AES-CTR, by NWM module in software. The AES key is stored in NWM module itself. See above for the CTR. The size of this encrypted data is 0x12 + (0x1E*val), where val is the u8 from networkstruct offset 0x1D.

Structure
Offset Size Description
0x0 0x10 MD5 over the rest of the data following this(plaintext).
0x10 0x2 u16 bitmask. Unknown, normally 0? Bit0 is for entry0, bit1 for entry1, and so on.
0x12 0x1E * <total array entries> This is an array of entries for each of the devices on this network, the first entry is for the host and the rest is for the client(s).
Array entry
Offset Size Description
0x0 0x1C This is the first 0x1C-bytes of the NodeInfo structure, stored as big-endian.
0x1C 0x2 u16 NetworkNodeID, stored as big-endian.

Each entry is for a node.

Mapped IO

All of the IO mapped under the NWM-module process is listed below:

Userland address Physical address Size Description
0x1EC22000 0x10122000 0x1000 WIFI_Registers
0x1EC40000 0x10140000 0x1000 PDN_Registers
0x1EE22000 0x10322000 0x1000

Errors

Error code Description
0xC8A06C0D The operation being performed is already done (e.g., if you run NWMEXT_ControlWirelessEnabled to turn wifi on when it's on already, you can't turn it on again).
0xC8A113EA Returned when the command isn't allowed to be used on this device.
0xC90113FA Node doesn't exist / invalid NetworkNodeID?
0xC92113FB Returned when trying to connect to a host when the host has the specified connection-type blocked via the network attributes. There might be other causes too.
0xE10113E9 Returned when the input size is invalid. Returned by NWMUDS:PullPacket when the input size is smaller than the frame_size.
0xE10113EA Invalid bind / data_channel is invalid(0x0).
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