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Minetest protocol (incomplete, early draft):
Updated 2011-06-18
A custom protocol over UDP.
Integers are big endian.
Refer to connection.{h,cpp} for further reference.
Initialization:
- A dummy reliable packet with peer_id=PEER_ID_INEXISTENT=0 is sent to the server:
- Actually this can be sent without the reliable packet header, too, i guess,
but the sequence number in the header allows the sender to re-send the
packet without accidentally getting a double initialization.
- Packet content:
# Basic header
u32 protocol_id = PROTOCOL_ID = 0x4f457403
u16 sender_peer_id = PEER_ID_INEXISTENT = 0
u8 channel = 0
# Reliable packet header
u8 type = TYPE_RELIABLE = 3
u16 seqnum = SEQNUM_INITIAL = 65500
# Original packet header
u8 type = TYPE_ORIGINAL = 1
# And no actual payload.
- Server responds with something like this:
- Packet content:
# Basic header
u32 protocol_id = PROTOCOL_ID = 0x4f457403
u16 sender_peer_id = PEER_ID_INEXISTENT = 0
u8 channel = 0
# Reliable packet header
u8 type = TYPE_RELIABLE = 3
u16 seqnum = SEQNUM_INITIAL = 65500
# Control packet header
u8 type = TYPE_CONTROL = 0
u8 controltype = CONTROLTYPE_SET_PEER_ID = 1
u16 peer_id_new = assigned peer id to client (other than 0 or 1)
- Then the connection can be disconnected by sending:
- Packet content:
# Basic header
u32 protocol_id = PROTOCOL_ID = 0x4f457403
u16 sender_peer_id = whatever was gotten in CONTROLTYPE_SET_PEER_ID
u8 channel = 0
# Control packet header
u8 type = TYPE_CONTROL = 0
u8 controltype = CONTROLTYPE_DISCO = 3
- Here's a quick untested connect-disconnect done in PHP:
# host: ip of server (use gethostbyname(hostname) to get from a dns name)
# port: port of server
function check_if_minetestserver_up($host, $port)
{
$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
$timeout = array("sec" => 1, "usec" => 0);
socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, $timeout);
$buf = "\x4f\x45\x74\x03\x00\x00\x00\x03\xff\xdc\x01";
socket_sendto($socket, $buf, strlen($buf), 0, $host, $port);
$buf = socket_read($socket, 1000);
if($buf != "")
{
# We got a reply! read the peer id from it.
$peer_id = substr($buf, 9, 2);
# Disconnect
$buf = "\x4f\x45\x74\x03".$peer_id."\x00\x00\x03";
socket_sendto($socket, $buf, strlen($buf), 0, $host, $port);
socket_close($socket);
return true;
}
return false;
}
- Here's a Python script for checking if a minetest server is up, confirmed working
#!/usr/bin/env python3
import sys, time, socket
address = ""
port = 30000
if len(sys.argv) <= 1:
print("Usage: %s <address>" % sys.argv[0])
exit()
if ":" in sys.argv[1]:
address = sys.argv[1].split(":")[0]
try:
port = int(sys.argv[1].split(":")[1])
except ValueError:
print("Please specify a valid port")
exit()
else:
address = sys.argv[1]
try:
start = time.time()
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.settimeout(2.0)
buf = b"\x4f\x45\x74\x03\x00\x00\x00\x01"
sock.sendto(buf, (address, port))
data, addr = sock.recvfrom(1000)
if data:
peer_id = data[12:14]
buf = b"\x4f\x45\x74\x03" + peer_id + b"\x00\x00\x03"
sock.sendto(buf, (address, port))
sock.close()
end = time.time()
print("%s is up (%0.5fms)" % (sys.argv[1], end - start))
else:
print("%s seems to be down " % sys.argv[1])
except Exception as err:
print("%s seems to be down (%s) " % (sys.argv[1], str(err)))
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