Harald Welte | 176e28c | 2010-12-19 22:56:58 +0100 | [diff] [blame] | 1 | % ip.access IPA multiplex protocol |
| 2 | |
| 3 | % (C) 2010 by Harald Welte <laforge@gnumonks.org> |
| 4 | % (C) 2010 by On-Waves |
| 5 | % |
| 6 | % All Rights Reserved |
| 7 | % |
| 8 | % This program is free software; you can redistribute it and/or modify |
| 9 | % it under the terms of the GNU General Public License as published by |
| 10 | % the Free Software Foundation; either version 2 of the License, or |
| 11 | % (at your option) any later version. |
| 12 | % |
| 13 | % This program is distributed in the hope that it will be useful, |
| 14 | % but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | % GNU General Public License for more details. |
| 17 | % |
| 18 | % You should have received a copy of the GNU General Public License along |
| 19 | % with this program; if not, write to the Free Software Foundation, Inc., |
| 20 | % 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 21 | |
| 22 | -module(ipa_proto). |
| 23 | -author('Harald Welte <laforge@gnumonks.org>'). |
| 24 | -compile(export_all). |
| 25 | |
| 26 | -define(TIMEOUT, 1000). |
| 27 | -define(IPA_SOCKOPTS, [binary, {packet, 0}, {reuseaddr, true}, {active, false}]). |
| 28 | |
| 29 | -define(IPAC_MSGT_PING, 0). |
| 30 | -define(IPAC_MSGT_PONG, 1). |
| 31 | -define(IPAC_MSGT_ID_GET, 4). |
| 32 | -define(IPAC_MSGT_ID_RESP, 5). |
| 33 | -define(IPAC_MSGT_ID_ACK, 6). |
| 34 | |
| 35 | -export([register_socket/1, register_stream/3, unregister_stream/2, |
| 36 | send/3, connect/3, connect/4, listen_accept_handle/2, |
| 37 | start_listen/3, controlling_process/3]). |
| 38 | |
| 39 | -record(ipa_socket, {socket, ipaPid, streamTbl, listenType}). |
| 40 | |
| 41 | |
| 42 | |
| 43 | % register a TCP socket with this IPA protocol implementation |
| 44 | register_socket(Socket) -> |
| 45 | IpaPid = spawn(?MODULE, init_sock, [Socket, self()]), |
| 46 | % synchronously wait for init_sock to be done |
| 47 | receive |
| 48 | {ipa_init_sock_done, Socket} -> |
| 49 | % assign ownership of the socket to the new IPA handler process |
| 50 | gen_tcp:controlling_process(Socket, IpaPid), |
| 51 | {ok, IpaPid} |
| 52 | after |
| 53 | ?TIMEOUT -> |
| 54 | {error, timeout} |
| 55 | end. |
| 56 | |
| 57 | % call_sync() preceeded by a Socket -> Pid lookup |
| 58 | call_sync_sock(Socket, Request) -> |
| 59 | % resolve PID responsible for this socket |
| 60 | case ets:lookup(ipa_sockets, Socket) of |
| 61 | [IpaSock] -> |
| 62 | call_sync(IpaSock#ipa_socket.ipaPid, Request); |
| 63 | _ -> |
| 64 | io:format("No Process for Socket ~p~n", [Socket]), |
| 65 | {error, no_sock_for_pid} |
| 66 | end. |
| 67 | |
| 68 | % a user process wants to register itself for a given Socket/StreamID tuple |
| 69 | register_stream(Socket, StreamID, Pid) -> |
| 70 | call_sync_sock(Socket, {ipa_reg_stream, Socket, StreamID, Pid}). |
| 71 | |
| 72 | register_streams(_S, []) -> |
| 73 | ok; |
| 74 | register_streams(S, [{StreamID, Pid}|SList]) -> |
| 75 | ipa_proto:register_stream(S, StreamID, Pid), |
| 76 | register_streams(S, SList). |
| 77 | |
| 78 | % unregister for a given stream |
| 79 | unregister_stream(Socket, StreamID) -> |
| 80 | call_sync_sock(Socket, {ipa_unreg_stream, Socket, StreamID}). |
| 81 | |
| 82 | % change the controlling process for a given {Socket, StreamID} |
| 83 | controlling_process(Socket, StreamID, NewPid) -> |
| 84 | call_sync_sock(Socket, {ipa_ctrl_proc, Socket, StreamID, NewPid}). |
| 85 | |
| 86 | % unblock the socket from further processing |
| 87 | unblock(Socket) -> |
| 88 | send_ccm_id_get(Socket), |
| 89 | call_sync_sock(Socket, {ipa_unblock, Socket}). |
| 90 | |
| 91 | |
| 92 | % server-side handler for unregister_stream() |
| 93 | request({ipa_reg_stream, Socket, StreamID, Pid}) -> |
| 94 | io:format("Registering handler ~p for socket ~p Stream ~p~n", [Pid, Socket, StreamID]), |
| 95 | [IpaSock] = ets:lookup(ipa_sockets, Socket), |
| 96 | ets:insert_new(IpaSock#ipa_socket.streamTbl, {{Socket, StreamID}, Pid}); |
| 97 | % server-side handler for unregister_stream() |
| 98 | request({ipa_unreg_stream, Socket, StreamID}) -> |
| 99 | io:format("Unregistering handler for Socket ~p Stream ~p~n", [Socket, StreamID]), |
| 100 | [IpaSock] = ets:lookup(ipa_sockets, Socket), |
| 101 | ets:delete(IpaSock#ipa_socket.streamTbl, {Socket, StreamID}); |
| 102 | % server-side handler for controlling_process() |
| 103 | request({ipa_ctrl_proc, Socket, StreamID, NewPid}) -> |
| 104 | io:format("Changing handler for socket ~p Stream ~p~n", [Socket, StreamID]), |
| 105 | [IpaSock] = ets:lookup(ipa_sockets, Socket), |
| 106 | ets:delete(IpaSock#ipa_socket.streamTbl, {Socket, StreamID}), |
| 107 | ets:insert_new(IpaSock#ipa_socket.streamTbl, {{Socket, StreamID}, NewPid}); |
| 108 | % server-side handler for unblock() |
| 109 | request({ipa_unblock, Socket}) -> |
| 110 | io:format("Unblocking socket ~p~n", [Socket]), |
| 111 | %[IpaSock] = ets:lookup(ipa_sockets, Socket), |
| 112 | Ret = inet:setopts(Socket, [{active, once}]), |
| 113 | io:format("Unblocking socket ~p:~p~n", [Socket, Ret]). |
| 114 | |
| 115 | % split an incoming IPA message and split it into Length/StreamID/Payload |
| 116 | split_ipa_msg(DataBin) -> |
| 117 | % FIXME: This will throw an exception if DataBin doesn't contain all payload |
| 118 | <<Length:16/big-unsigned-integer, StreamID:8, Payload:Length/binary, Trailer/binary>> = DataBin, |
| 119 | io:format("Stream ~p, ~p bytes~n", [StreamID, Length]), |
| 120 | {StreamID, Payload, Trailer}. |
| 121 | |
| 122 | % deliver an incoming message to the process that is registered for the socket/stream_id |
| 123 | deliver_rx_ipa_msg(Socket, StreamID, StreamMap, DataBin) -> |
| 124 | case ets:lookup(StreamMap, {Socket, StreamID}) of |
| 125 | [{_,{process_id, Pid}}] -> |
| 126 | Pid ! {ipa, Socket, StreamID, DataBin}; |
| 127 | [{_,{callback_fn, Fn, Args}}] -> |
| 128 | Fn(Socket, StreamID, DataBin, Args); |
| 129 | [] -> |
| 130 | io:format("No Pid registered for Socket ~p Stream ~p~n", [Socket, StreamID]) |
| 131 | end. |
| 132 | |
| 133 | % process (split + deliver) an incoming IPA message |
| 134 | process_rx_ipa_msg(_S, _StreamMap, <<>>) -> |
| 135 | ok; |
| 136 | process_rx_ipa_msg(S, StreamMap, Data) -> |
| 137 | {StreamID, PayloadBin, Trailer} = split_ipa_msg(Data), |
| 138 | case StreamID of |
| 139 | 254 -> |
| 140 | process_rx_ccm_msg(S, StreamID, PayloadBin); |
| 141 | _ -> |
| 142 | deliver_rx_ipa_msg(S, StreamID, StreamMap, PayloadBin) |
| 143 | end, |
| 144 | process_rx_ipa_msg(S, StreamMap, Trailer). |
| 145 | |
| 146 | send_close_signal([]) -> |
| 147 | ok; |
| 148 | send_close_signal([StreamSpec|Tail]) -> |
| 149 | io:format("FIXME: send_close_signal ~p ~p~n", [StreamSpec, Tail]), |
| 150 | %[{{Socket, StreamID, Pid}}] = StreamSpec, |
| 151 | %Pid ! {ipa_closed, {Socket, StreamID}}, |
| 152 | send_close_signal(Tail). |
| 153 | |
| 154 | process_tcp_closed(S, StreamMap) -> |
| 155 | % signal the closed socket to the user |
| 156 | StreamList = ets:match(StreamMap, '$1'), |
| 157 | send_close_signal(StreamList), |
| 158 | % remove the stream map for this socket |
| 159 | ets:delete(StreamMap), |
| 160 | % remove any entry regarding 'S' from ipa_sockets |
| 161 | ets:delete(ipa_sockets, S), |
| 162 | ok. |
| 163 | |
| 164 | % send a binary message through a given Socket / StreamID |
| 165 | send(Socket, StreamID, DataBin) -> |
| 166 | Size = byte_size(DataBin), |
| 167 | gen_tcp:send(Socket, iolist_to_binary([<<Size:2/big-unsigned-integer-unit:8>>, StreamID, DataBin])). |
| 168 | |
| 169 | |
| 170 | call_sync(Pid, Request) -> |
| 171 | Ref = make_ref(), |
| 172 | Pid ! {request, {self(), Ref}, Request}, |
| 173 | receive |
| 174 | {reply, Ref, Reply} -> Reply |
| 175 | after |
| 176 | ?TIMEOUT -> {error, timeout} |
| 177 | end. |
| 178 | |
| 179 | reply({From, Ref}, Reply) -> |
| 180 | From ! {reply, Ref, Reply}. |
| 181 | |
| 182 | |
| 183 | % global module initialization |
| 184 | init() -> |
| 185 | case ets:new(ipa_sockets, [named_table, set, public, {keypos, #ipa_socket.socket}]) of |
| 186 | ipa_sockets -> |
| 187 | ok; |
| 188 | _ -> |
| 189 | {error, ets_new_ipa_sockets} |
| 190 | end. |
| 191 | |
| 192 | % initialize a signle socket, create its handle process |
| 193 | init_sock(Socket, CallingPid) -> |
| 194 | StreamMap = ets:new(stream_map, [set]), |
| 195 | ets:insert(ipa_sockets, #ipa_socket{socket=Socket, ipaPid=self(), streamTbl=StreamMap}), |
| 196 | CallingPid ! {ipa_init_sock_done, Socket}, |
| 197 | loop(Socket, StreamMap). |
| 198 | |
| 199 | loop(S, StreamMap) -> |
| 200 | receive |
| 201 | {request, From, Request} -> |
| 202 | Reply = ipa_proto:request(Request), |
| 203 | ipa_proto:reply(From, Reply), |
| 204 | ipa_proto:loop(S, StreamMap); |
| 205 | {ipa_send, S, StreamId, Data} -> |
| 206 | send(S, StreamId, Data), |
| 207 | ipa_proto:loop(S, StreamMap); |
| 208 | {tcp, S, Data} -> |
| 209 | % process incoming IPA message and mark socket active once more |
| 210 | ipa_proto:process_rx_ipa_msg(S, StreamMap, Data), |
| 211 | inet:setopts(S, [{active, once}]), |
| 212 | ipa_proto:loop(S, StreamMap); |
| 213 | {tcp_closed, S} -> |
| 214 | io:format("Socket ~w closed [~w]~n", [S,self()]), |
| 215 | ipa_proto:process_tcp_closed(S, StreamMap), |
| 216 | % terminate the process by not looping further |
| 217 | ok |
| 218 | end. |
| 219 | |
| 220 | % Respond with PONG to PING |
| 221 | process_ccm_msg(Socket, StreamID, ?IPAC_MSGT_PING, _) -> |
| 222 | io:format("Socket ~p Stream ~p: PING -> PONG~n", [Socket, StreamID]), |
| 223 | send(Socket, StreamID, <<?IPAC_MSGT_PONG>>); |
| 224 | % Simply respond to ID_ACK with ID_ACK |
| 225 | process_ccm_msg(_Socket, _StreamID, ?IPAC_MSGT_ID_ACK, _) -> |
| 226 | % send(Socket, StreamID, <<?IPAC_MSGT_ID_ACK>>); |
| 227 | ok; |
| 228 | % Simply respond to ID_RESP with ID_ACK |
| 229 | process_ccm_msg(Socket, StreamID, ?IPAC_MSGT_ID_RESP, _) -> |
| 230 | io:format("Socket ~p Stream ~p: ID_RESP -> ID_ACK~n", [Socket, StreamID]), |
| 231 | send(Socket, StreamID, <<?IPAC_MSGT_ID_ACK>>); |
| 232 | % Default message handler for unknown messages |
| 233 | process_ccm_msg(Socket, StreamID, MsgType, Opts) -> |
| 234 | io:format("Socket ~p Stream ~p: Unknown CCM message type ~p Opts ~p~n", |
| 235 | [Socket, StreamID, MsgType, Opts]). |
| 236 | |
| 237 | % process an incoming CCM message (Stream ID 254) |
| 238 | process_rx_ccm_msg(Socket, StreamID, PayloadBin) -> |
| 239 | [MsgType|Opts] = binary:bin_to_list(PayloadBin), |
| 240 | process_ccm_msg(Socket, StreamID, MsgType, Opts). |
| 241 | |
| 242 | send_ccm_id_get(Socket) -> |
| 243 | send(Socket, 254, <<?IPAC_MSGT_ID_GET>>). |
| 244 | |
| 245 | % convenience wrapper for interactive use / debugging from the shell |
| 246 | listen_accept_handle(LPort, Opts) -> |
| 247 | case gen_tcp:listen(LPort, ?IPA_SOCKOPTS ++ Opts) of |
| 248 | {ok, ListenSock} -> |
| 249 | {ok, Port} = inet:port(ListenSock), |
| 250 | {ok, Sock} = gen_tcp:accept(ListenSock), |
| 251 | {ok, IpaPid} = ipa_proto:register_socket(Sock), |
| 252 | ipa_proto:register_stream(Sock, 0, self()), |
| 253 | ipa_proto:register_stream(Sock, 255, self()), |
| 254 | gen_tcp:controlling_process(Sock, IpaPid), |
| 255 | {ok, Port}; |
| 256 | {error, Reason} -> |
| 257 | {error, Reason} |
| 258 | end. |
| 259 | |
| 260 | % gen_tcp:connect() convenience wrappers |
| 261 | connect(Address, Port, Options) -> |
| 262 | connect(Address, Port, Options, infinity). |
| 263 | |
| 264 | connect(Address, Port, Options, Timeout) -> |
| 265 | case gen_tcp:connect(Address, Port, ?IPA_SOCKOPTS ++ Options, Timeout) of |
| 266 | {ok, Socket} -> |
| 267 | case ipa_proto:register_socket(Socket) of |
| 268 | {ok, _} -> |
| 269 | {ok, Socket}; |
| 270 | {error, Reason} -> |
| 271 | gen_tcp:close(Socket), |
| 272 | {error, Reason} |
| 273 | end; |
| 274 | {error, Reason} -> |
| 275 | {error, Reason} |
| 276 | end. |
| 277 | |
| 278 | % Utility function to continuously server incomming IPA connections on a |
| 279 | % listening TCP socket |
| 280 | start_listen(LPort, NumServers, Opts) -> |
| 281 | case gen_tcp:listen(LPort, ?IPA_SOCKOPTS ++ Opts) of |
| 282 | {ok, ListenSock} -> |
| 283 | start_servers(NumServers, ListenSock, self()), |
| 284 | {ok, Port} = inet:port(ListenSock), |
| 285 | Port; |
| 286 | {error, Reason} -> |
| 287 | {error, Reason} |
| 288 | end. |
| 289 | |
| 290 | start_servers(0, _, _) -> |
| 291 | ok; |
| 292 | start_servers(Num, LS, CtrlPid) -> |
| 293 | spawn(?MODULE, listen_server, [LS, CtrlPid]), |
| 294 | start_servers(Num-1, LS, CtrlPid). |
| 295 | |
| 296 | listen_server(LS, CtrlPid) -> |
| 297 | case gen_tcp:accept(LS) of |
| 298 | {ok, S} -> |
| 299 | io:format("Accepted TCP connection from ~p~n", [inet:peername(S)]), |
| 300 | % assign the socket to the Controlling process |
| 301 | gen_tcp:controlling_process(S, CtrlPid), |
| 302 | CtrlPid ! {ipa_tcp_accept, S}, |
| 303 | listen_server(LS, CtrlPid); |
| 304 | Other -> |
| 305 | io:format("accept returned ~w - goodbye!~n", [Other]), |
| 306 | ok |
| 307 | end. |