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