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Diffstat (limited to 'lib/ssh/test/ssh_relay.erl')
| -rw-r--r-- | lib/ssh/test/ssh_relay.erl | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/lib/ssh/test/ssh_relay.erl b/lib/ssh/test/ssh_relay.erl new file mode 100644 index 0000000000..28000fbb97 --- /dev/null +++ b/lib/ssh/test/ssh_relay.erl @@ -0,0 +1,407 @@ +%%%------------------------------------------------------------------- +%%% @author Simon Cornish <[email protected]> +%%% @copyright (C) 2015, Simon Cornish +%%% @doc +%%% Provide manipulatable TCP-level relaying for testing SSH +%%% @end +%%% Created : 7 May 2015 by Simon Cornish <[email protected]> +%%%------------------------------------------------------------------- +-module(ssh_relay). + +-behaviour(gen_server). + +%% API +-export([start_link/4]). +-export([stop/1]). +-export([hold/4, release/2, release_next/3]). + +%% gen_server callbacks +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, + terminate/2, code_change/3]). + +-record(hold, { + port, + n, + tmo, + tref, + q = [] + }). + +-record(state, { + local_addr, + local_port, + peer_addr, + peer_port, + lpid, + local, + peer, + tx_hold, + rx_hold + }). + +-define(ACCEPT_TMO, 200). +%%%=================================================================== +%%% API +%%%=================================================================== +%%-------------------------------------------------------------------- +%% @doc +%% Hold N (or 'all') messages in given direction. +%% Messages will be released after the N+1th message or +%% Tmo ms or 'infinity' +%% +%% Dir is 'tx' for direction local -> peer +%% and 'rx' for direction peer -> local +%% +%% An Error, ealready, is returned if there is already a hold +%% in the given direction +%% +%% @spec hold(Srv, Dir, N, Tmo) -> ok | {error, Error} +%% @end +%%-------------------------------------------------------------------- +hold(Srv, Dir, N, Tmo) -> + gen_server:call(Srv, {hold, Dir, N, Tmo}). + +%%-------------------------------------------------------------------- +%% @doc +%% Release all held messages in given direction. +%% +%% An Error, enoent, is returned if there is no hold +%% in the given direction +%% +%% @spec release(Srv, Dir) -> ok | {error, Error} +%% @end +%%-------------------------------------------------------------------- +release(Srv, Dir) -> + gen_server:call(Srv, {release, Dir}). + +%%-------------------------------------------------------------------- +%% @doc +%% Release all held messages in given direction after the +%% next message in the trigger direction +%% +%% An Error, enoent, is returned if there is no hold +%% in the given direction +%% +%% @spec release_next(Srv, Dir, TriggerDir) -> ok | {error, Error} +%% @end +%%-------------------------------------------------------------------- +release_next(Srv, Dir, TriggerDir) -> + gen_server:call(Srv, {release_next, Dir, TriggerDir}). + +%%-------------------------------------------------------------------- +%% @doc +%% Starts the server +%% +%% @spec start_link() -> {ok, Pid} | ignore | {error, Error} +%% @end +%%-------------------------------------------------------------------- +start_link(ListenAddr, ListenPort, PeerAddr, PeerPort) -> + gen_server:start_link(?MODULE, [ListenAddr, ListenPort, PeerAddr, PeerPort], []). + +stop(Srv) -> + unlink(Srv), + Srv ! stop. + +%%%=================================================================== +%%% gen_server callbacks +%%%=================================================================== + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Initializes the server +%% +%% @spec init(Args) -> {ok, State} | +%% {ok, State, Timeout} | +%% ignore | +%% {stop, Reason} +%% @end +%%-------------------------------------------------------------------- +init([ListenAddr, ListenPort, PeerAddr, PeerPort | _Options]) -> + IfAddr = case ListenAddr of + {0,0,0,0} -> + []; + _ -> + [{ifaddr, ListenAddr}] + end, + case gen_tcp:listen(ListenPort, [{reuseaddr, true}, {backlog, 1}, {active, false}, binary | IfAddr]) of + {ok, LSock} -> + Parent = self(), + {LPid, _LMod} = spawn_monitor(fun() -> listen(Parent, LSock) end), + S = #state{local_addr = ListenAddr, + local_port = ListenPort, + lpid = LPid, + peer_addr = PeerAddr, + peer_port = PeerPort + }, + {ok, S}; + Error -> + {stop, Error} + end. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Handling call messages +%% +%% @spec handle_call(Request, From, State) -> +%% {reply, Reply, State} | +%% {reply, Reply, State, Timeout} | +%% {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, Reply, State} | +%% {stop, Reason, State} +%% @end +%%-------------------------------------------------------------------- +handle_call({hold, Dir, N, Tmo}, _From, State) -> + case Dir of + tx -> + do_hold(#state.tx_hold, State#state.peer, N, Tmo, State); + rx -> + do_hold(#state.rx_hold, State#state.local, N, Tmo, State); + _ -> + {reply, {error, einval}, State} + end; +handle_call({release, Dir}, _From, State) -> + case Dir of + tx -> + do_release(#state.tx_hold, State); + rx -> + do_release(#state.rx_hold, State); + _ -> + {reply, {error, einval}, State} + end; +handle_call({release_next, _Dir, _TriggerDir}, _From, State) -> + {reply, {error, nyi}, State}; + +handle_call(Request, _From, State) -> + Reply = {unhandled, Request}, + {reply, Reply, State}. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Handling cast messages +%% +%% @spec handle_cast(Msg, State) -> {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} +%% @end +%%-------------------------------------------------------------------- +handle_cast(_Msg, State) -> + {noreply, State}. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Handling all non call/cast messages +%% +%% @spec handle_info(Info, State) -> {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} +%% @end +%%-------------------------------------------------------------------- +handle_info({tcp, Local, Data}, S) when S#state.local == Local -> + S1 = do_local(Data, S), + {noreply, S1}; + +handle_info({tcp_error, Local, Error}, S) when S#state.local == Local -> + S1 = do_local({error, Error}, S), + {noreply, S1}; + +handle_info({tcp_closed, Local}, S) when S#state.local == Local -> + S1 = do_local(closed, S), + {noreply, S1}; + +handle_info({tcp, Peer, Data}, S) when S#state.peer == Peer -> + S1 = do_peer(Data, S), + {noreply, S1}; + +handle_info({tcp_error, Peer, Error}, S) when S#state.peer == Peer -> + S1 = do_peer({error, Error}, S), + {noreply, S1}; + +handle_info({tcp_closed, Peer}, S) when S#state.peer == Peer -> + S1 = do_peer(closed, S), + {noreply, S1}; + +handle_info({accept, Local}, S) -> + S1 = do_accept(Local, S), + {noreply, S1}; + +handle_info({activate, Local}, State) -> + inet:setopts(Local, [{active, true}]), + {noreply, State}; + +handle_info({release, Pos}, S) -> + {reply, _, S1} = do_release(Pos,S), + {noreply, S1}; + +handle_info(stop, State) -> + {stop, normal, State}; + +handle_info({'DOWN', _Ref, _process, LPid, Reason}, S) when S#state.lpid == LPid -> + io:format("Acceptor has finished: ~p~n", [Reason]), + {noreply, S}; + +handle_info(_Info, State) -> + io:format("Unhandled info: ~p~n", [_Info]), + {noreply, State}. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% This function is called by a gen_server when it is about to +%% terminate. It should be the opposite of Module:init/1 and do any +%% necessary cleaning up. When it returns, the gen_server terminates +%% with Reason. The return value is ignored. +%% +%% @spec terminate(Reason, State) -> void() +%% @end +%%-------------------------------------------------------------------- +terminate(_Reason, _State) -> + ok. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Convert process state when code is changed +%% +%% @spec code_change(OldVsn, State, Extra) -> {ok, NewState} +%% @end +%%-------------------------------------------------------------------- +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +%%%=================================================================== +%%% Internal functions +%%%=================================================================== +do_hold(Pos, _Port, _N, _Tmo, S) when element(Pos, S) /= undefined -> + {reply, {error, ealready}, S}; +do_hold(Pos, Port, N, Tmo, S) -> + TRef = if is_integer(Tmo) andalso Tmo > 0 -> + erlang:send_after(Tmo, self(), {release, Pos}); + true -> + undefined + end, + Hold = #hold{port = Port, n = N, tmo = Tmo, tref = TRef}, + {reply, ok, setelement(Pos, S, Hold)}. + +do_release(HPos, S) when element(HPos, S) == undefined -> + {reply, {error, enoent}, S}; +do_release(HPos, S) -> + #hold{port = Port, tref = TRef, q = Q} = element(HPos, S), + lists:foreach(fun(M) -> gen_tcp:send(Port, M), erlang:yield() end, Q), + catch erlang:cancel_timer(TRef), + receive + {release, HPos} -> ok + after 0 -> + ok + end, + {reply, ok, setelement(HPos, S, undefined)}. + +listen(Parent, LSock) -> + monitor(process, Parent), + do_listen(Parent, LSock). + +do_listen(Parent, LSock) -> + %% So annoying there is no select-like sematic for this + case gen_tcp:accept(LSock, ?ACCEPT_TMO) of + {ok, Sock} -> + Parent ! {accept, Sock}, + gen_tcp:controlling_process(Sock, Parent), + Parent ! {activate, Sock}, + do_flush(Parent, Sock), + gen_tcp:close(LSock); + {error, timeout} -> + receive + DOWN when element(1, DOWN) == 'DOWN' -> + ok; + stop -> + ok + after 1 -> + do_listen(Parent, LSock) + end; + Error -> + gen_tcp:close(LSock), + exit({accept,Error}) + end. + +do_flush(Parent, Sock) -> + receive + {Tcp, Sock, _} = Msg when Tcp == tcp; Tcp == tcp_error -> + Parent ! Msg, + do_flush(Parent, Sock); + {tcp_closed, Sock} = Msg -> + Parent ! Msg, + do_flush(Parent, Sock) + after 1 -> + ok + end. + +do_accept(Local, S) -> + case gen_tcp:connect(S#state.peer_addr, S#state.peer_port, [{active, true}, binary]) of + {ok, Peer} -> + S#state{local = Local, peer = Peer}; + Error -> + exit({connect, Error}) + end. + +do_local(Data, S) when is_binary(Data) -> + TxH = S#state.tx_hold, + if TxH == undefined -> + gen_tcp:send(S#state.peer, Data), + S; + TxH#hold.n == 0 -> + lists:foreach(fun(M) -> gen_tcp:send(S#state.peer, M) end, TxH#hold.q), + gen_tcp:send(S#state.peer, Data), + catch erlang:cancel_timer(TxH#hold.tref), + TxP = #state.tx_hold, + receive + {release, TxP} -> + ok + after 0 -> + ok + end, + S#state{tx_hold = undefined}; + true -> + Q = TxH#hold.q ++ [Data], + N = if is_integer(TxH#hold.n) -> + TxH#hold.n -1; + true -> + TxH#hold.n + end, + S#state{tx_hold = TxH#hold{q = Q, n = N}} + end; +do_local(Error, _S) -> + exit({local, Error}). + +do_peer(Data, S) when is_binary(Data) -> + RxH = S#state.rx_hold, + if RxH == undefined -> + gen_tcp:send(S#state.local, Data), + S; + RxH#hold.n == 0 -> + lists:foreach(fun(M) -> gen_tcp:send(S#state.local, M) end, RxH#hold.q), + gen_tcp:send(S#state.local, Data), + catch erlang:cancel_timer(RxH#hold.tref), + RxP = #state.rx_hold, + receive + {release, RxP} -> + ok + after 0 -> + ok + end, + S#state{rx_hold = undefined}; + true -> + Q = RxH#hold.q ++ [Data], + N = if is_integer(RxH#hold.n) -> + RxH#hold.n -1; + true -> + RxH#hold.n + end, + S#state{rx_hold = RxH#hold{q = Q, n = N}} + end; +do_peer(Error, _S) -> + exit({peer, Error}). + |