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-rw-r--r--lib/common_test/test/Makefile1
-rw-r--r--lib/common_test/test/telnet_server.erl217
2 files changed, 218 insertions, 0 deletions
diff --git a/lib/common_test/test/Makefile b/lib/common_test/test/Makefile
index 94569fa87f..31ab28c41d 100644
--- a/lib/common_test/test/Makefile
+++ b/lib/common_test/test/Makefile
@@ -28,6 +28,7 @@ MODULES= \
ct_test_support \
ct_test_support_eh \
ct_userconfig_callback \
+ telnet_server \
ct_smoke_test_SUITE \
ct_priv_dir_SUITE \
ct_event_handler_SUITE \
diff --git a/lib/common_test/test/telnet_server.erl b/lib/common_test/test/telnet_server.erl
new file mode 100644
index 0000000000..5843155eee
--- /dev/null
+++ b/lib/common_test/test/telnet_server.erl
@@ -0,0 +1,217 @@
+-module(telnet_server).
+-compile(export_all).
+
+%% telnet control characters
+-define(SE, 240).
+-define(NOP, 241).
+-define(DM, 242).
+-define(BRK, 243).
+-define(IP, 244).
+-define(AO, 245).
+-define(AYT, 246).
+-define(EC, 247).
+-define(EL, 248).
+-define(GA, 249).
+-define(SB, 250).
+-define(WILL, 251).
+-define(WONT, 252).
+-define(DO, 253).
+-define(DONT, 254).
+-define(IAC, 255).
+
+%% telnet options
+-define(BINARY, 0).
+-define(ECHO, 1).
+-define(SUPPRESS_GO_AHEAD, 3).
+-define(TERMINAL_TYPE, 24).
+
+-record(state,
+ {listen,
+ client,
+ users,
+ authorized=false,
+ suppress_go_ahead=false,
+ buffer=[]}).
+
+-type options() :: [{port,pos_integer()} | {users,users()}].
+-type users() :: [{user(),password()}].
+-type user() :: string().
+-type password() :: string().
+
+-spec start(Opts::options()) -> Pid::pid().
+start(Opts) when is_list(Opts) ->
+ spawn_link(fun() -> init(Opts) end).
+
+-spec stop(Pid::pid()) -> ok.
+stop(Pid) ->
+ Ref = erlang:monitor(process,Pid),
+ Pid ! stop,
+ receive {'DOWN',Ref,_,_,_} -> ok end.
+
+init(Opts) ->
+ Port = proplists:get_value(port,Opts),
+ Users = proplists:get_value(users,Opts,[]),
+ {ok, LSock} = gen_tcp:listen(Port, [list, {packet, 0},
+ {active, true}]),
+ State = #state{listen=LSock,users=Users},
+ accept(State),
+ ok = gen_tcp:close(LSock).
+
+accept(#state{listen=LSock}=State) ->
+ Server = self(),
+ Acceptor = spawn_link(fun() -> do_accept(LSock,Server) end),
+ receive
+ {Acceptor,Sock} when is_port(Sock) ->
+ case init_client(State#state{client=Sock}) of
+ stopped ->
+ io:format("telnet_server stopped\n"),
+ ok;
+ R ->
+ io:format("connection to client closed with reason ~p~n",[R]),
+ accept(State)
+ end;
+ {Acceptor,closed} ->
+ io:format("listen socket closed unexpectedly, "
+ "terminating telnet_server\n"),
+ ok;
+ stop ->
+ io:format("telnet_server stopped\n"),
+ ok
+ end.
+
+do_accept(LSock,Server) ->
+ case gen_tcp:accept(LSock) of
+ {ok, Sock} ->
+ ok = gen_tcp:controlling_process(Sock,Server),
+ Server ! {self(),Sock};
+ {error,closed} ->
+ %% This will happen when stop/1 is called, since listen
+ %% socket is closed. Then the server is probably already
+ %% dead by now, but to be 100% sure not to hang, we send a
+ %% message to say what happened.
+ Server ! {self(),closed}
+ end.
+
+init_client(#state{client=Sock}=State) ->
+ R = case gen_tcp:send(Sock,"login: ") of
+ ok ->
+ loop(State);
+ Error ->
+ Error
+ end,
+ _ = gen_tcp:close(Sock),
+ R.
+
+loop(State) ->
+ receive
+ {tcp,_,Data} ->
+ try handle_data(Data,State) of
+ {ok,State1} ->
+ loop(State1)
+ catch
+ throw:Error ->
+ Error
+ end;
+ {tcp_closed, _} ->
+ closed;
+ {tcp_error,_,Error} ->
+ {error,tcp,Error};
+ stop ->
+ stopped
+ end.
+
+handle_data([?IAC|Cmd],State) ->
+ dbg("Server got cmd: ~p~n",[Cmd]),
+ handle_cmd(Cmd,State);
+handle_data(Data,State) ->
+ dbg("Server got data: ~p~n",[Data]),
+ case get_line(Data,[]) of
+ {Line,Rest} ->
+ WholeLine = lists:flatten(lists:reverse(State#state.buffer,Line)),
+ {ok,State1} = do_handle_data(WholeLine,State),
+ case Rest of
+ [] -> {ok,State1};
+ _ -> handle_data(Rest,State1)
+ end;
+ false ->
+ {ok,State#state{buffer=[Data|State#state.buffer]}}
+ end.
+
+%% Add function clause below to handle new telnet commands (sent with
+%% ?IAC from client - this is not possible to do from ct_telnet API,
+%% but ct_telnet sends DONT SUPPRESS_GO_AHEAD)
+handle_cmd([?DO,?SUPPRESS_GO_AHEAD|T],State) ->
+ send([?IAC,?WILL,?SUPPRESS_GO_AHEAD],State),
+ handle_cmd(T,State#state{suppress_go_ahead=true});
+handle_cmd([?DONT,?SUPPRESS_GO_AHEAD|T],State) ->
+ send([?IAC,?WONT,?SUPPRESS_GO_AHEAD],State),
+ handle_cmd(T,State#state{suppress_go_ahead=false});
+handle_cmd([?IAC|T],State) ->
+ %% Multiple commands in one packet
+ handle_cmd(T,State);
+handle_cmd([_H|T],State) ->
+ %% Not responding to this command
+ handle_cmd(T,State);
+handle_cmd([],State) ->
+ {ok,State}.
+
+%% Add function clause below to handle new text command (text entered
+%% from the telnet prompt)
+do_handle_data(Data,#state{authorized=false}=State) ->
+ check_user(Data,State);
+do_handle_data(Data,#state{authorized={user,_}}=State) ->
+ check_pwd(Data,State);
+do_handle_data("echo "++ Data,State) ->
+ send(Data++"\r\n> ",State),
+ {ok,State};
+do_handle_data("repeat "++ Data,State) ->
+ send(Data++"\r\n"++Data++"\r\n> ",State),
+ {ok,State};
+do_handle_data([],State) ->
+ send("> ",State),
+ {ok,State};
+do_handle_data(_Data,State) ->
+ send("error: unknown command\r\n> ",State),
+ {ok,State}.
+
+check_user(User,State) ->
+ case lists:keyfind(User,1,State#state.users) of
+ {User,Pwd} ->
+ dbg("user ok\n"),
+ send("Password: ",State),
+ {ok,State#state{authorized={user,Pwd}}};
+ false ->
+ throw({error,unknown_user})
+ end.
+
+check_pwd(Pwd,#state{authorized={user,Pwd}}=State) ->
+ dbg("password ok\n"),
+ send("Welcome to the ultimate telnet server!\r\n> ",State),
+ {ok,State#state{authorized=true}};
+check_pwd(_,_State) ->
+ throw({error,authentication}).
+
+send(Data,State) ->
+ dbg("Server sending: ~p~n",[Data]),
+ case gen_tcp:send(State#state.client,Data) of
+ ok ->
+ ok;
+ {error,Error} ->
+ throw({error,send,Error})
+ end.
+
+get_line([$\r,$\n|Rest],Acc) ->
+ {lists:reverse(Acc),Rest};
+get_line([$\r,0|Rest],Acc) ->
+ {lists:reverse(Acc),Rest};
+get_line([$\n|Rest],Acc) ->
+ {lists:reverse(Acc),Rest};
+get_line([H|T],Acc) ->
+ get_line(T,[H|Acc]);
+get_line([],_) ->
+ false.
+
+dbg(_F) ->
+ io:format(_F).
+dbg(_F,_A) ->
+ io:format(_F,_A).
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