Update doc/lua_api.txt

[oweals/minetest.git] / doc / protocol.txt

diff --git a/doc/protocol.txt b/doc/protocol.txt
index 93037e70b637ec2075d76992bd42e903e94f6349..82dca59bfc617da485c66eab75867a4ca856a443 100644 (file)
--- a/doc/protocol.txt
+++ b/doc/protocol.txt
@@ -2,6 +2,8 @@ Minetest-c55 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:
@@ -15,7 +17,7 @@ Initialization:
                u8 channel = 0
                # Reliable packet header
                u8 type = TYPE_RELIABLE = 3
-               u16 seqnum = SEQNUM_INITIAL = 6550
+               u16 seqnum = SEQNUM_INITIAL = 65500
                # Original packet header
                u8 type = TYPE_ORIGINAL = 1
                # And no actual payload.
@@ -27,7 +29,7 @@ Initialization:
                u8 channel = 0
                # Reliable packet header
                u8 type = TYPE_RELIABLE = 3
-               u16 seqnum = SEQNUM_INITIAL = 6550
+               u16 seqnum = SEQNUM_INITIAL = 65500
                # Control packet header
                u8 type = TYPE_CONTROL = 0
                u8 controltype = CONTROLTYPE_SET_PEER_ID = 1
@@ -40,5 +42,31 @@ Initialization:
                u8 channel = 0
                # Control packet header
                u8 type = TYPE_CONTROL = 0
-               u8 controltype = CONTROLTYPE_DISCO = 2
+               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;
+}