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Diffstat (limited to 'lib/ssh/src/ssh_channel.erl')
-rw-r--r-- | lib/ssh/src/ssh_channel.erl | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/lib/ssh/src/ssh_channel.erl b/lib/ssh/src/ssh_channel.erl new file mode 100644 index 0000000000..3d67065ee1 --- /dev/null +++ b/lib/ssh/src/ssh_channel.erl @@ -0,0 +1,328 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2008-2009. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% + +%% + +-module(ssh_channel). + +-include("ssh_connect.hrl"). + +-behaviour(gen_server). + +%%% API +-export([behaviour_info/1, start/4, start/5, start_link/4, start_link/5, call/2, call/3, + cast/2, reply/2, enter_loop/1]). + +%% gen_server callbacks +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, + terminate/2, code_change/3]). + +%% Internal application API +-export([cache_create/0, cache_lookup/2, cache_update/2, + cache_delete/1, cache_delete/2, cache_foldl/3, + cache_find/2]). + +-record(state, { + cm, + channel_cb, + channel_state, + channel_id, + close_sent = false + }). + +%%==================================================================== +%% API +%%==================================================================== + +%%% Optionel callbacks handle_call/3, handle_cast/2, handle_msg/2, +%%% code_change/3 +behaviour_info(callbacks) -> + [ + {init, 1}, + {terminate, 2}, + {handle_ssh_msg, 2}, + {handle_msg, 2} + ]. + + +call(ChannelPid, Msg) -> + call(ChannelPid, Msg, infinity). + +call(ChannelPid, Msg, TimeOute) -> + try gen_server:call(ChannelPid, Msg, TimeOute) of + Result -> + Result + catch + exit:{noproc, _} -> + {error, closed}; + exit:{timeout, _} -> + {error, timeout} + end. + + +cast(ChannelPid, Msg) -> + gen_server:cast(ChannelPid, Msg). + + +reply(From, Msg) -> + gen_server:reply(From, Msg). + +%%==================================================================== +%% Internal application API +%%==================================================================== + +%%-------------------------------------------------------------------- +%% Function: start_link() -> {ok,Pid} | ignore | {error,Error} +%% Description: Starts the server +%%-------------------------------------------------------------------- +start(ConnectionManager, ChannelId, CallBack, CbInitArgs) -> + start(ConnectionManager, ChannelId, CallBack, CbInitArgs, undefined). + +start(ConnectionManager, ChannelId, CallBack, CbInitArgs, Exec) -> + Options = [{channel_cb, CallBack}, + {channel_id, ChannelId}, + {init_args, CbInitArgs}, + {cm, ConnectionManager}, + {exec, Exec}], + gen_server:start(?MODULE, [Options], []). + +start_link(ConnectionManager, ChannelId, CallBack, CbInitArgs) -> + start_link(ConnectionManager, ChannelId, CallBack, CbInitArgs, undefined). + +start_link(ConnectionManager, ChannelId, CallBack, CbInitArgs, Exec) -> + Options = [{channel_cb, CallBack}, + {channel_id, ChannelId}, + {init_args, CbInitArgs}, + {cm, ConnectionManager}, + {exec, Exec}], + gen_server:start_link(?MODULE, [Options], []). + +enter_loop(State) -> + gen_server:enter_loop(?MODULE, [], State). + +%%==================================================================== +%% gen_server callbacks +%%==================================================================== + +%%-------------------------------------------------------------------- +%% Function: init(Args) -> {ok, State} | +%% {ok, State, Timeout} | +%% ignore | +%% {stop, Reason} +%% Description: Initiates the server +%%-------------------------------------------------------------------- +init([Options]) -> + Cb = proplists:get_value(channel_cb, Options), + ConnectionManager = proplists:get_value(cm, Options), + ChannelId = proplists:get_value(channel_id, Options), + process_flag(trap_exit, true), + InitArgs = + case proplists:get_value(exec, Options) of + undefined -> + proplists:get_value(init_args, Options); + Exec -> + proplists:get_value(init_args, Options) ++ [Exec] + end, + try Cb:init(InitArgs) of + {ok, ChannelState} -> + State = #state{cm = ConnectionManager, + channel_cb = Cb, + channel_id = ChannelId, + channel_state = ChannelState}, + self() ! {ssh_channel_up, ChannelId, ConnectionManager}, + {ok, State}; + {ok, ChannelState, Timeout} -> + State = #state{cm = ConnectionManager, + channel_cb = Cb, + channel_id = ChannelId, + channel_state = ChannelState}, + self() ! {ssh_channel_up, ChannelId, ConnectionManager}, + {ok, State, Timeout}; + {stop, Why} -> + {stop, Why} + catch + _:Reason -> + {stop, Reason} + end. + +%%-------------------------------------------------------------------- +%% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} | +%% {reply, Reply, State, Timeout} | +%% {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, Reply, State} | +%% {stop, Reason, State} +%% Description: Handling call messages +%%-------------------------------------------------------------------- +handle_call(Request, From, #state{channel_cb = Module, + channel_state = ChannelState} = State) -> + try Module:handle_call(Request, From, ChannelState) of + Result -> + handle_cb_result(Result, State) + catch + error:{undef, _} -> + {noreply, State} + end. + + +%%-------------------------------------------------------------------- +%% Function: handle_cast(Msg, State) -> {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} +%% Description: Handling cast messages +%%-------------------------------------------------------------------- +handle_cast(Msg, #state{channel_cb = Module, + channel_state = ChannelState} = State) -> + + try Module:handle_cast(Msg, ChannelState) of + Result -> + handle_cb_result(Result, State) + catch + error:{undef, _} -> + {noreply, State} + end. + +%%-------------------------------------------------------------------- +%% Function: handle_info(Info, State) -> {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} +%% Description: Handling all non call/cast messages +%%-------------------------------------------------------------------- +handle_info({ssh_cm, ConnectionManager, {closed, _ChannelId}}, + #state{cm = ConnectionManager, + close_sent = true} = State) -> + {stop, normal, State}; +handle_info({ssh_cm, ConnectionManager, {closed, ChannelId}}, + #state{cm = ConnectionManager, + close_sent = false} = State) -> + %% To be on the safe side, i.e. the manager has already been terminated. + (catch ssh_connection:close(ConnectionManager, ChannelId)), + {stop, normal, State}; + +handle_info({ssh_cm, _, _} = Msg, #state{cm = ConnectionManager, + channel_cb = Module, + channel_state = ChannelState0} = State) -> + case Module:handle_ssh_msg(Msg, ChannelState0) of + {ok, ChannelState} -> + adjust_window(Msg), + {noreply, State#state{channel_state = ChannelState}}; + {ok, ChannelState, Timeout} -> + adjust_window(Msg), + {noreply, State#state{channel_state = ChannelState}, Timeout}; + {stop, ChannelId, ChannelState} -> + ssh_connection:close(ConnectionManager, ChannelId), + {stop, normal, State#state{close_sent = true, + channel_state = ChannelState}} + end; + +handle_info(Msg, #state{cm = ConnectionManager, channel_cb = Module, + channel_state = ChannelState0} = State) -> + case Module:handle_msg(Msg, ChannelState0) of + {ok, ChannelState} -> + {noreply, State#state{channel_state = ChannelState}}; + {ok, ChannelState, Timeout} -> + {noreply, State#state{channel_state = ChannelState}, Timeout}; + {stop, ChannelId, ChannelState} -> + ssh_connection:close(ConnectionManager, ChannelId), + {stop, normal, State#state{close_sent = true, + channel_state = ChannelState}} + end. + +%%-------------------------------------------------------------------- +%% Function: terminate(Reason, State) -> void() +%% Description: 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. +%%-------------------------------------------------------------------- +terminate(Reason, #state{cm = ConnectionManager, + channel_id = ChannelId, + close_sent = false} = State) -> + ssh_connection:close(ConnectionManager, ChannelId), + terminate(Reason, State#state{close_sent = true}); +terminate(_, #state{channel_cb = Cb, channel_state = ChannelState}) -> + catch Cb:terminate(Cb, ChannelState), + ok. + +%%-------------------------------------------------------------------- +%% Func: code_change(OldVsn, State, Extra) -> {ok, NewState} +%% Description: Convert process state when code is changed +%%-------------------------------------------------------------------- +code_change(OldVsn, #state{channel_cb = Module, + channel_state = ChannelState0} = State, Extra) -> + {ok, ChannelState} = Module:code_change(OldVsn, ChannelState0, Extra), + {ok, State#state{channel_state = ChannelState}}. + +%%==================================================================== +%% Internal application API +%%==================================================================== +cache_create() -> + ets:new(cm_tab, [set,{keypos, #channel.local_id}]). + +cache_lookup(Cache, Key) -> + case ets:lookup(Cache, Key) of + [Channel] -> + Channel; + [] -> + undefined + end. + +cache_update(Cache, #channel{local_id = Id} = Entry) when Id =/= undefined -> + ets:insert(Cache, Entry). + +cache_delete(Cache, Key) -> + ets:delete(Cache, Key). + +cache_delete(Cache) -> + ets:delete(Cache). + +cache_foldl(Fun, Acc, Cache) -> + ets:foldl(Fun, Acc, Cache). + +cache_find(ChannelPid, Cache) -> + case ets:match_object(Cache, #channel{user = ChannelPid}) of + [] -> + undefined; + [Channel] -> + Channel + end. + +%%-------------------------------------------------------------------- +%%% Internal functions +%%-------------------------------------------------------------------- +handle_cb_result({reply, Reply, ChannelState}, State) -> + {reply, Reply, State#state{channel_state = ChannelState}}; +handle_cb_result({reply, Reply, ChannelState, Timeout}, State) -> + {reply, Reply,State#state{channel_state = ChannelState}, Timeout}; +handle_cb_result({noreply, ChannelState}, State) -> + {noreply, State#state{channel_state = ChannelState}}; +handle_cb_result({noreply, ChannelState, Timeout}, State) -> + {noreply, State#state{channel_state = ChannelState}, Timeout}; +handle_cb_result({stop, Reason, Reply, ChannelState}, State) -> + {stop, Reason, Reply, State#state{channel_state = ChannelState}}; +handle_cb_result({stop, Reason, ChannelState}, State) -> + {stop, Reason, State#state{channel_state = ChannelState}}. + +adjust_window({ssh_cm, ConnectionManager, + {data, ChannelId, _, Data}}) -> + ssh_connection:adjust_window(ConnectionManager, ChannelId, size(Data)); +adjust_window(_) -> + ok. + + |