emqx/apps/emqx_gateway_coap/src/emqx_coap_proxy_conn.erl

68 lines
2.5 KiB
Erlang

%%--------------------------------------------------------------------
%% Copyright (c) 2021-2024 EMQ Technologies Co., Ltd. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%--------------------------------------------------------------------
-module(emqx_coap_proxy_conn).
-behaviour(esockd_udp_proxy_connection).
-include("emqx_coap.hrl").
-export([initialize/1, find_or_create/4, get_connection_id/4, dispatch/3, close/2]).
%%--------------------------------------------------------------------
%% Callbacks
%%--------------------------------------------------------------------
initialize(_Opts) ->
emqx_coap_frame:initial_parse_state(#{}).
find_or_create(CId, Transport, Peer, Opts) ->
case emqx_gateway_cm_registry:lookup_channels(coap, CId) of
[Pid] ->
{ok, Pid};
[] ->
emqx_gateway_conn:start_link(Transport, Peer, Opts)
end.
get_connection_id(_Transport, _Peer, State, Data) ->
case parse_incoming(Data, [], State) of
{[Msg | _] = Packets, NState} ->
case emqx_coap_message:extract_uri_query(Msg) of
#{
<<"clientid">> := ClientId
} ->
{ok, ClientId, Packets, NState};
_ ->
ErrMsg = <<"Missing token or clientid in connection mode">>,
Reply = emqx_coap_message:piggyback({error, bad_request}, ErrMsg, Msg),
Bin = emqx_coap_frame:serialize_pkt(Reply, emqx_coap_frame:serialize_opts()),
{error, Bin}
end;
_Error ->
invalid
end.
dispatch(Pid, _State, Packet) ->
erlang:send(Pid, Packet).
close(Pid, _State) ->
erlang:send(Pid, udp_proxy_closed).
parse_incoming(<<>>, Packets, State) ->
{Packets, State};
parse_incoming(Data, Packets, State) ->
{ok, Packet, Rest, NParseState} = emqx_coap_frame:parse(Data, State),
parse_incoming(Rest, [Packet | Packets], NParseState).