Stepmania Protocol

Introduction

Stepmania use his own protocol SMLan. It’s composed of 3 parts.

Size|Command|Payload

  • Size: size of packets.
  • Command: Command to use
  • Payload: data which depend of the command used.

Size type:

  • MSN: Most signifiant 4 bits. Eg. 11110000 -> 1111 represents the 4 most signifiant bits (15 in decimal)
  • LSN: Least signifiant 4 bits. EG. 00001111 -> 1111 represents the 4 least signifiant bits (15 in decimal)
  • NT: Null terminating string.
  • X: Integer store in X bytes.

The protocol is implemented in smserver.smutils.smpacket module

SMClient Packet

000: Ping

This command will cause server to respond with a PingR response.

Payload: None.

See smserver.smutils.smpacket.SMPacketClientNSCPing

001: PingR

This command is used to respond to a ping packet.

Payload: None.

See smserver.smutils.smpacket.SMPacketClientNSCPingR

002: Hello

This is the first packet from a client to server. It introduce the client to the server.

Payload:

Size Description
1 Client protocol version
NT Name of the stepmania build

See smserver.smutils.smpacket.SMPacketClientNSCHello

003: Game Start Request

This command is called once after most loading is done, and again immediately before the sound starts.

Payload:

Size Description
MSN Primary player difficulty (feet) (0 for no player)
LSN Secondary player difficulty (feet) (0 for no player)
MSN Primary player difficulty (0=Beginner, 1=easy, etc.)
LSN Second player difficulty (0=Beginner, 1=easy, etc.)
MSN Start Position (0 is pre-sync, 1 is for sync)
LSN Reserved
NT Song Title
NT Song Subtitle
NT Song Artist
NT Course Title (If none exists; make it just a null)
NT Song Options (in string-format)
NT Primary Player’s options (Null if non-existant)
NT Secondary Player’s Options (Null if non-existant)

See smserver.smutils.smpacket.SMPacketClientNSCGSR

004: Game Over Notice

This command is sent when end of game is encounterd

Payload: None.

See smserver.smutils.smpacket.SMPacketClientNSCGON

005: Game Status update

Updates game info for each step

Size Description
MSN Player #
LSN

StepID:

  • 1: HitMine
  • 2: AvoidMine
  • 3: Miss
  • 4: W5
  • 5: W4
  • 6: W3
  • 7: W2
  • 8: W1
  • 9: LetGo
  • 10: Held
MSN Projected Grade (StepMania enum int)
LSN Reserved
4 Net-order long containing score.
2 Net-order int containing combo.
2 Net-order int containing health.
2 Net-order # containing offset. 32767 would be DEAD on the note. If the user is hitting late, the # will be higher. It if the user is exactly 0.25 seconds off, the number will be different by 500, if 0.5, it will be different by 1000.)

See smserver.smutils.smpacket.SMPacketClientNSCGSU

006: Style Update

This is sent when a profile is choosed. It also indicates the number of players in the local client. (1 or 2)

Payload:

Size Description
1 Number of players in the client (1 or 2)
1 Player id. (0 or 1)
NT Player name for this id

See smserver.smutils.smpacket.SMPacketClientNSCSU

007: Chat message

Sent when a user type a message on the general chat

Payload:

Size Description
NT Message

See smserver.smutils.smpacket.SMPacketClientNSCCM

008: Request Start Game and Tell server existance/non existance of song.

The user selected a song on a Net-enabled selection

Payload:

Size Description
1

Usage of message

  • 0: (in response to server 8) User has specified song,
  • 1: (in response to server 8) User does NOT have specified song,
  • 2: User requested a start game on given song)
NT Song Title (As gotten by GetTranslitMainTitle)
NT Song Artist (As Gotten by GetTranslitArtist)
NT Song Subtitle (As gotten by GetTranslitSubTitle)

See smserver.smutils.smpacket.SMPacketClientNSCRSG

009: reserved

nothing

See smserver.smutils.smpacket.SMPacketClientNSCUUL

010: User status

Indicate where the user is.

Payload:

Size Description
1

Indicate where the user is:

  • 0: exited ScreenNetSelectMusic
  • 1: entered ScreenNetSelectMusic
  • 2: Not Sent
  • 3: entered options screen
  • 4: exited the evaluation screen
  • 5: entered evaluation screen
  • 6: exited ScreenNetRoom
  • 7: entered ScreenNetRoom

See smserver.smutils.smpacket.SMPacketClientNSSCSMS

011: User has changed player options

Payload:

Size Description
NT Player 0’s options
NT Player 1’s options

See smserver.smutils.smpacket.SMPacketClientNSCUOpts

012: SMOnline Packet

Use to send custom SMO client packet.

Payload:

Size Description
SMOPacket A SMO packet (Command + SMO payload).

See smserver.smutils.smpacket.SMPacketClientNSSMONL

015: XMLPacket

This packet contains XML data. Don’t know yet when it is used.

Payload:

Size Description
NT XML Data

See smserver.smutils.smpacket.SMPacketClientXMLPacket

SMServer Packet

The command start at 128 for server response.

128: Ping

This command will cause client to respond with a PingR command

Payload: None.

See smserver.smutils.smpacket.SMPacketServerNSCPing

129: PingR

This command is used to respond to a Ping command.

Payload: None.

See smserver.smutils.smpacket.SMPacketServerNSCPingR

130: Hello

This command introduces the server. (In response of Client Hello command)

Payload:

Size Description
1 Server protocol version (128 for SMOnline server)
NT Server name
4 Random key (at the moment only used for hash password on login)

See smserver.smutils.smpacket.SMPacketServerNSCHello

131: Allow Start

This will cause the client to start the game

Payload: None

See smserver.smutils.smpacket.SMPacketServerNSCGSR

132: Game Over Stats

This packet is send in response to the game over packet. It contains information regarding how well each player did.

Payload:

Size Description
1 NB of players sent in this packet. This determine the lenght of all the list send after
  • 1
  • 1
  • 1
  • 1
  • First player’s index
  • Second player’s index
  • ...
  • Last player’s index
4..4 Player’s scores
1..1

Player’s grades:

  • 0: AAAA
  • 1: AAA
  • 2: AA
  • 3: A
  • 4: B
  • 5: C
  • 6: D
  • 7: F
1..1

Player’s difficulties:

  • 0: Beginner
  • 1: Easy
  • 2: Medium
  • 3: Hard
  • 4: Expert
2..2 NB of Player’s flawless
2..2 NB of Player’s perfect
2..2 NB of Player’s great
2..2 NB of Player’s good
2..2 NB of Player’s boo
2..2 NB of Player’s miss
2..2 NB of Player’s held
2..2 NB of Player’s max_combo
NT..NT Player’s Options

See smserver.smutils.smpacket.SMPacketServerNSCGON

133: Scoreboard update

This will update the client’s scoreboard.

Payload:

Size Description
1

Which section to update in the scoreboard

  • 0: Update the names
  • 1: Update the combos
  • 2: Update the grade
1 NB of players sent in this packet. This determine the lenght of all the list send after
1..1

If usage is names:

List of player’s index (determine by the NSCUUL packet)
2..2

If usage is combos:

List of player’s combo
1..1

If usage is grades:

List of player’s grades

See smserver.smutils.smpacket.SMPacketServerNSCGSU

134: System Message

Send a system message to user

Payload:

Size Description
NT Message

See smserver.smutils.smpacket.SMPacketServerNSCSU

135: Chat message

Add a chat message to the chat window on some StepMania screens.

Payload:

Size Description
NT Message

See smserver.smutils.smpacket.SMPacketServerNSCCM

136: Request Start Game

Tell client to start song/ask if client has song

Payload:

Size Description
1

Usage of message

  • 0: see if client has song
  • 1: see if client has song, if so, scroll to song
  • 2: See if client has song, if so, scroll to song, and play it
  • 3: Blindly start song
NT Song Title (As gotten by GetTranslitMainTitle)
NT Song Artist (As Gotten by GetTranslitArtist)
NT Song Subtitle (As gotten by GetTranslitSubTitle)

See smserver.smutils.smpacket.SMPacketServerNSCRSG

137: Update User List

This sends all the users currently connected

Pay attention of the user’s order in this packet. The index of each user will server for NSCGON and NSCGSU packet.

Size Description
1 Number max of player’s allowed
1 NB of players sent in this packet. This determine the lenght of all the list send after
1

First player’s status

  • 0: Inactive (no info on this user yet)
  • 1: Active (You know who is is)
  • 2: In music selection screen
  • 3: In options
  • 4: In evaluation
NT First player’s name
...  
1 Last player’s status
NT Last player’s name

See smserver.smutils.smpacket.SMPacketServerNSCCUUL

138: Change to Select Music Screen

Force change to Networking select music screen.

Payload:

Size Description
NT Set specified gametype
NT Set specified style

See smserver.smutils.smpacket.SMPacketServerNSSCSMS

140: SMOnline Packet

The SMLan packet 140 is a wrapper for the SMOnline packet.

Payload:

Size Description
SMOPacket A SMO packet (Command + SMO payload).

See smserver.smutils.smpacket.SMPacketServerNSSMONL

141: Formatted information packet

Send formatted information regarding the server back to the player.

Payload:

Size Description
NT Server Name
2 Port the server is listening on
2 Number of players connected

See smserver.smutils.smpacket.SMPacketServerNSCFormatted

142: Attack Client

Payload:

Size Description
1 Player # (0 or 1)
4 Time to last (in ms)
NT Text describing modifiers

See smserver.smutils.smpacket.SMPacketServerNSCAttack

143: XMLPacket

This packet contains XML data. Don’t know yet when it is used.

Payload:

Size Description
NT XML Data

See smserver.smutils.smpacket.SMPacketServerXMLPacket

SMOClient Packet

SMOServer Packet