doc/protocol.txt

   1 Minetest-c55 protocol (incomplete, early draft):
   2 Updated 2011-06-18
   3
   4 A custom protocol over UDP.
   5
   6 Initialization:
   7 - A dummy reliable packet with peer_id=PEER_ID_INEXISTENT=0 is sent to the server:
   8         - Actually this can be sent without the reliable packet header, too, i guess,
   9           but the sequence number in the header allows the sender to re-send the
  10           packet without accidentally getting a double initialization.
  11         - Packet content:
  12                 # Basic header
  13                 u32 protocol_id = PROTOCOL_ID = 0x4f457403
  14                 u16 sender_peer_id = PEER_ID_INEXISTENT = 0
  15                 u8 channel = 0
  16                 # Reliable packet header
  17                 u8 type = TYPE_RELIABLE = 3
  18                 u16 seqnum = SEQNUM_INITIAL = 65500
  19                 # Original packet header
  20                 u8 type = TYPE_ORIGINAL = 1
  21                 # And no actual payload.
  22 - Server responds with something like this:
  23         - Packet content:
  24                 # Basic header
  25                 u32 protocol_id = PROTOCOL_ID = 0x4f457403
  26                 u16 sender_peer_id = PEER_ID_INEXISTENT = 0
  27                 u8 channel = 0
  28                 # Reliable packet header
  29                 u8 type = TYPE_RELIABLE = 3
  30                 u16 seqnum = SEQNUM_INITIAL = 65500
  31                 # Control packet header
  32                 u8 type = TYPE_CONTROL = 0
  33                 u8 controltype = CONTROLTYPE_SET_PEER_ID = 1
  34                 u16 peer_id_new = assigned peer id to client (other than 0 or 1)
  35 - Then the connection can be disconnected by sending:
  36         - Packet content:
  37                 # Basic header
  38                 u32 protocol_id = PROTOCOL_ID = 0x4f457403
  39                 u16 sender_peer_id = whatever was gotten in CONTROLTYPE_SET_PEER_ID
  40                 u8 channel = 0
  41                 # Control packet header
  42                 u8 type = TYPE_CONTROL = 0
  43                 u8 controltype = CONTROLTYPE_DISCO = 2
  44