Raknet Protocol

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Revision as of 12:05, 8 June 2020 by Orladog (talk | contribs) (Fix formatting of Unconnected Ping)
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RakNet is a networking library used by Minecraft Bedrock Edition. You might want to also look at the documentation for the Bedrock Protocol.

This is based on the old Pocket Edition Protocol Documentation and may be incomplete or outdated.

The source code for the RakNet Library can be found here.

Other implementations exist, such as JRakLibPlus and RakLib.

Data types

Size (Bytes) Range Notes
Byte 1 0 to 255
Long 8 -2^63 to 2^63-1 Signed 64-bit Integer
Magic 16 00ffff00fefefefefdfdfdfd12345678 Always those hex bytes, corresponding to RakNet's default OFFLINE_MESSAGE_DATA_ID
short 2 -32768 to 32767
unsigned short 2 0 to 65535
string unsigned short + string N/A Prefixed by a short containing the length of the string in characters. It appears that only the following ASCII characters can be displayed: !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~

Packets

Unconnected Ping

Packet ID Field Name Field Type Notes
0x01, 0x02 Time Long
MAGIC magic
Client GUID Long

0x02 is only replied to if there are open connections to the server. Note: as of 0.15.6 it seems that the game refreshes it's LAN world list every 4-5 seconds, however it seems the game will still ping in 1 second intervals.
This packet should be responded to with unconnected Pong.

Unconnected Pong

Packet ID Field Name Field Type Notes
0x1c Time Long
Server GUID Long
MAGIC magic
Server ID string string Used for the MOTD. See below for details.

Server ID string format

For Minecraft Bedrock this is separated by semicolons and uses the following format:
MCPE;MOTD line 1;Protocol Version;Version Name;Player Count;Max Player Count;Server Unique ID;MOTD line 2;Gamemode;Unknown;Port (IPv4);Port (IPv6);
Example:
MCPE;Dedicated Server;390;1.14.60;0;10;13253860892328930865;Bedrock level;Survival;1;19132;19133;
Result:
Server ID String Example.png

Connected Ping

Packet ID Field Name Field Type Notes
0x00 Time Long

Connected Pong

Packet ID Field Name Field Type Notes
0x03 Ping Time Long
Pong Time Long

Offline Connection Request 1

Packet ID Field Name Field Type Notes
0x05 Magic MAGIC
Protocol version byte Currently 7
MTU mtu-46 zero bytes The MTU sent in the response appears to be somewhere around the size of this padding + 46 (28 udp overhead, 1 packet id, 16 magic, 1 protocol version)

The client sends these to the target server with ever decreasing MTU until the server responds. This is used to discover the MTU size for the connection. If the RakNet protocol does not match your own, respond with the Incompatible protocol packet

Offline Connection Response 1

Packet ID Field Name Field Type Notes
0x06 Magic MAGIC
Server GUID Long
Use security boolean Make sure this is false, it is vital for the login sequence to continue!
MTU short see Offline Connection Request 1

Offline Connection Request 2

Packet ID Field Name Field Type Notes
0x07 Magic MAGIC
Server Address address
MTU short
Client GUID Long

Offline Connection Response 2

Packet ID Field Name Field Type Notes
0x08 Magic MAGIC
Server GUID Long
Client Address address
MTU short
Encryption enabled? byte 0 for disabled.

Online Connection Request

Packet ID Field Name Field Type Notes
0x09 GUID Long
Time Long

Online Connection Request Accepted

Packet ID Field Name Field Type Notes
0x10 Client address address
System index short Unknown what this does. 0 works as a value.
Internal IDs 10x address Unknown what these do. 255.255.255.255:19132 for all of them seems to work, any other address will probably work as well.
Request time Long
Time Long

Incompatible protocol

Packet ID Field Name Field Type Notes
0x19 Protocol byte
Magic MAGIC
Server GUID Long

Unconnected Ping

Packet ID Field Name Field Type Notes
0x01, 0x02 Time Long
GUID Long

Frame Set Packet

Packet ID Field Name Field Type Notes
0x80..0x8d Frame Set index uint24le
Frames Flags byte Top 3 bits are reliability type, fourth bit is 1 when the frame is fragmented and part of a compound.
Length IN BITS short Length of the body in bits.
Reliable frame index uint24le only if reliable
Sequenced frame index uint24le only if sequenced
Order Ordered frame index uint24le only if ordered
Order channel byte
Fragment Compound size int only if fragmented
Compound ID short
Index int
Body ceil(length/8) bytes

The reliability types are as follows:

ID Name Reliable Ordered Sequenced
0 unreliable
1 unreliable sequenced x x
2 reliable x
3 reliable ordered x x
4 reliable sequenced x x x
5 unreliable (+ ACK receipt)
6 reliable (+ ACK receipt) x
7 reliable ordered (+ ACK receipt) x x

Sequenced implies ordered.

Game Packet

Packet ID Field Name Field Type Notes
0x8e Body bytes Single packet of the GAME protocol.

NACK

Packet ID Field Name Field Type Notes
0xa0 Record count short
Record Is Range? byte 0 for range, 1 for no range
No Range Index uint24le
Range Start Index uint24le
End Index uint24le

ACK

Packet ID Field Name Field Type Notes
0xc0 Record count short
Record Is Range? byte 0 for range, 1 for no range
No Range Index uint24le
Range Start Index uint24le
End Index uint24le