Parses binary packets into records.

src/parser.erl

@@ -0,0 +1,142 @@
+%%% @author Niclas Axelsson <niclas@burbas.se>
+%%% @copyright (C) 2010, Niclas Axelsson
+%%% @doc
+%%% Parser for messages sent from client-side
+%%% @end
+%%% Created : 22 Oct 2010 by Niclas Axelsson <niclas@burbas.se>
+
+-module(parser).
+
+-include("../include/client_packets.hrl").
+-include("../include/types.hrl").
+
+-export([parse_header/1]).
+
+parse_header(<<?mc_byte(PacketID), Rest/binary>>) ->
+    case PacketID of
+	1 ->
+	    <<?mc_int(ProtocolVersion), ?mc_short(UsernameLength), RRest/binary>> = Rest,
+	    ULength = 8*UsernameLength,
+	    <<Username:ULength/native-signed-integer, ?mc_short(_PasswordLength), Password/binary>> = RRest,
+	    #login_request{
+			    protocol_version = ProtocolVersion,
+			    username = Username, 
+			    password = Password
+			  };
+	2 ->
+	    <<?mc_short(_Length), Username/binary>> = Rest,
+	    #handshake{
+			username = erlang:binary_to_list(Username)
+		      };
+	3 ->
+	    <<?mc_short(_Length), Message/binary>> = Rest,
+	      #chat_message{
+			     message = Message
+			   };
+	5 ->
+	    <<?mc_int(Type), ?mc_short(Count), Payload/binary>> = Rest,
+	    ParsedPayload = parse_payload(Payload),
+	    #player_inventory{
+			       type = Type,
+			       count = Count,
+			       payload = ParsedPayload
+			     };
+	10 ->
+	    <<?mc_byte(OnGround)>> = Rest,
+	    OG = case OnGround of
+		     0 -> false;
+		     1 -> true
+		 end,
+	    #player{
+		     on_ground = OG
+		  };
+	11 ->
+	    <<?mc_double(X), ?mc_double(Y), ?mc_double(Stance), ?mc_double(Z), ?mc_byte(OnGround)>> = Rest,
+	    OG = case OnGround of
+		     0 -> false;
+		     1 -> true
+		 end,
+	    #player_position{
+		   x = X,
+		   y = Y,
+		   stance = Stance,
+		   z = Z,
+		   on_ground = OG
+		  };
+	12 ->
+	    <<?mc_float(Yaw), ?mc_float(Pitch), ?mc_byte(OnGround)>> = Rest,
+	    OG = case OnGround of
+		     0 -> false;
+		     1 -> true
+		 end,
+	    #player_look{
+		   yaw = Yaw,
+		   pitch = Pitch,
+		   on_ground = OG
+		  };
+	13 ->
+	    <<?mc_double(X), ?mc_double(Y), ?mc_double(Stance), ?mc_double(Z), ?mc_float(Yaw), ?mc_float(Pitch), ?mc_byte(OnGround)>> = Rest,
+	    OG = case OnGround of
+		     0 -> false;
+		     1 -> true
+		 end,
+	    #player_position_and_look{
+		   x = X,
+		   y = Y,
+		   stance = Stance,
+		   z = Z,
+		   yaw = Yaw,
+		   pitch = Pitch,
+		   on_ground = OG
+		  };
+	14 ->
+	    <<?mc_byte(Status), ?mc_int(X), ?mc_byte(Y), ?mc_int(Z), ?mc_byte(Face)>> = Rest,
+	    #player_digging{
+			     status = Status,
+			     x = X,
+			     y = Y,
+			     z = Z,
+			     face = Face
+			   };
+	15 ->
+	    <<?mc_short(ItemID), ?mc_int(X), ?mc_byte(Y), ?mc_int(Z), ?mc_byte(Direction)>> = Rest,
+	    #player_block_placement{
+				     item_id = ItemID,
+				     x = X,
+				     y = Y,
+				     z = Z,
+				     direction = Direction
+				   };
+	16 ->
+	    <<?mc_int(_Unused), ?mc_short(ItemID)>> = Rest,
+	    #holding_change{
+			     item_id = ItemID
+			   };
+	255 ->
+	    <<?mc_short(_Length), Reason/binary>> = Rest,
+	    #disconnect{
+	      reason = Reason
+	     };
+	_ ->
+	    error
+    end.
+
+
+
+
+
+
+
+
+parse_payload(Payload) ->
+    parse_payload(Payload, []).
+
+parse_payload(<<>>, Acc) ->
+    lists:reverse(Acc);
+parse_payload(<<?mc_short(-1), Payload/binary>>, Acc) ->
+    parse_payload(Payload, [{empty} | Acc]);
+parse_payload(<<?mc_short(ItemID), ?mc_byte(Count), ?mc_short(Health), Payload/binary>>, Acc) ->
+    parse_payload(Payload, [{ItemID, Count, Health} | Acc]).
+
+
+