%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2008-2017. 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.
%%
%% %CopyrightEnd%
%%
%%
%%----------------------------------------------------------------------
%% Purpose: Details of connection protocol
%%----------------------------------------------------------------------
-module(ssh_connection).
-include("ssh.hrl").
-include("ssh_connect.hrl").
-include("ssh_transport.hrl").
%% API
-export([session_channel/2, session_channel/4,
exec/4, shell/2, subsystem/4, send/3, send/4, send/5,
send_eof/2, adjust_window/3, setenv/5, close/2, reply_request/4,
ptty_alloc/3, ptty_alloc/4]).
%% Potential API currently unsupported and not tested
-export([window_change/4, window_change/6,
signal/3, exit_status/3]).
%% Internal SSH application API
-export([channel_data/5,
handle_msg/3,
handle_stop/1,
channel_adjust_window_msg/2,
channel_close_msg/1,
channel_open_failure_msg/4,
channel_open_msg/5,
channel_status_msg/1,
channel_data_msg/3,
channel_eof_msg/1,
channel_failure_msg/1,
channel_open_confirmation_msg/4,
channel_request_msg/4,
channel_success_msg/1,
request_failure_msg/0,
request_success_msg/1,
bind/4, unbind/3, unbind_channel/2,
bound_channel/3, encode_ip/1
]).
-type connection_ref() :: ssh:connection_ref().
-type channel_id() :: ssh:channel_id().
%%--------------------------------------------------------------------
%%% API
%%--------------------------------------------------------------------
%%--------------------------------------------------------------------
%% Description: Opens a channel for a ssh session. A session is a
%% remote execution of a program. The program may be a shell, an
%% application, a system command, or some built-in subsystem.
%% --------------------------------------------------------------------
-spec session_channel(connection_ref(), timeout()) ->
{ok, channel_id()} | {error, timeout | closed}.
session_channel(ConnectionHandler, Timeout) ->
session_channel(ConnectionHandler, ?DEFAULT_WINDOW_SIZE, ?DEFAULT_PACKET_SIZE, Timeout).
-spec session_channel(connection_ref(), integer(), integer(), timeout()) ->
{ok, channel_id()} | {error, timeout | closed}.
session_channel(ConnectionHandler, InitialWindowSize, MaxPacketSize, Timeout) ->
case ssh_connection_handler:open_channel(ConnectionHandler, "session", <<>>,
InitialWindowSize,
MaxPacketSize, Timeout) of
{open, Channel} ->
{ok, Channel};
Error ->
Error
end.
%%--------------------------------------------------------------------
%% Description: Will request that the server start the
%% execution of the given command.
%%--------------------------------------------------------------------
-spec exec(connection_ref(), channel_id(), string(), timeout()) ->
success | failure | {error, timeout | closed}.
exec(ConnectionHandler, ChannelId, Command, TimeOut) ->
ssh_connection_handler:request(ConnectionHandler, self(), ChannelId, "exec",
true, [?string(Command)], TimeOut).
%%--------------------------------------------------------------------
%% Description: Will request that the user's default shell (typically
%% defined in /etc/passwd in UNIX systems) be started at the other
%% end.
%%--------------------------------------------------------------------
-spec shell(connection_ref(), channel_id()) ->
ok | success | failure | {error, timeout}.
shell(ConnectionHandler, ChannelId) ->
ssh_connection_handler:request(ConnectionHandler, self(), ChannelId,
"shell", false, <<>>, 0).
%%--------------------------------------------------------------------
%%
%% Description: Executes a predefined subsystem.
%%--------------------------------------------------------------------
-spec subsystem(connection_ref(), channel_id(), string(), timeout()) ->
success | failure | {error, timeout | closed}.
subsystem(ConnectionHandler, ChannelId, SubSystem, TimeOut) ->
ssh_connection_handler:request(ConnectionHandler, self(),
ChannelId, "subsystem",
true, [?string(SubSystem)], TimeOut).
%%--------------------------------------------------------------------
%% Description: Sends channel data.
%%--------------------------------------------------------------------
-spec send(connection_ref(), channel_id(), iodata()) ->
ok | {error, timeout | closed}.
send(ConnectionHandler, ChannelId, Data) ->
send(ConnectionHandler, ChannelId, 0, Data, infinity).
-spec send(connection_ref(), channel_id(), integer()| iodata(), timeout() | iodata()) ->
ok | {error, timeout | closed}.
send(ConnectionHandler, ChannelId, Data, TimeOut) when is_integer(TimeOut) ->
send(ConnectionHandler, ChannelId, 0, Data, TimeOut);
send(ConnectionHandler, ChannelId, Data, infinity) ->
send(ConnectionHandler, ChannelId, 0, Data, infinity);
send(ConnectionHandler, ChannelId, Type, Data) ->
send(ConnectionHandler, ChannelId, Type, Data, infinity).
-spec send(connection_ref(), channel_id(), integer(), iodata(), timeout()) ->
ok | {error, timeout | closed}.
send(ConnectionHandler, ChannelId, Type, Data, TimeOut) ->
ssh_connection_handler:send(ConnectionHandler, ChannelId,
Type, Data, TimeOut).
%%--------------------------------------------------------------------
-spec send_eof(connection_ref(), channel_id()) -> ok | {error, closed}.
%%
%%
%% Description: Sends eof on the channel <ChannelId>.
%%--------------------------------------------------------------------
send_eof(ConnectionHandler, Channel) ->
ssh_connection_handler:send_eof(ConnectionHandler, Channel).
%%--------------------------------------------------------------------
-spec adjust_window(connection_ref(), channel_id(), integer()) -> ok.
%%
%%
%% Description: Adjusts the ssh flowcontrol window.
%%--------------------------------------------------------------------
adjust_window(ConnectionHandler, Channel, Bytes) ->
ssh_connection_handler:adjust_window(ConnectionHandler, Channel, Bytes).
%%--------------------------------------------------------------------
-spec setenv(connection_ref(), channel_id(), string(), string(), timeout()) ->
success | failure | {error, timeout | closed}.
%%
%%
%% Description: Environment variables may be passed to the shell/command to be
%% started later.
%%--------------------------------------------------------------------
setenv(ConnectionHandler, ChannelId, Var, Value, TimeOut) ->
ssh_connection_handler:request(ConnectionHandler, ChannelId,
"env", true, [?string(Var), ?string(Value)], TimeOut).
%%--------------------------------------------------------------------
-spec close(connection_ref(), channel_id()) -> ok.
%%
%%
%% Description: Sends a close message on the channel <ChannelId>.
%%--------------------------------------------------------------------
close(ConnectionHandler, ChannelId) ->
ssh_connection_handler:close(ConnectionHandler, ChannelId).
%%--------------------------------------------------------------------
-spec reply_request(connection_ref(), boolean(), success | failure, channel_id()) -> ok.
%%
%%
%% Description: Send status replies to requests that want such replies.
%%--------------------------------------------------------------------
reply_request(ConnectionHandler, true, Status, ChannelId) ->
ssh_connection_handler:reply_request(ConnectionHandler, Status, ChannelId);
reply_request(_,false, _, _) ->
ok.
%%--------------------------------------------------------------------
%% Description: Sends a ssh connection protocol pty_req.
%%--------------------------------------------------------------------
-spec ptty_alloc(connection_ref(), channel_id(), proplists:proplist()) ->
success | failure | {error, timeout}.
ptty_alloc(ConnectionHandler, Channel, Options) ->
ptty_alloc(ConnectionHandler, Channel, Options, infinity).
-spec ptty_alloc(connection_ref(), channel_id(), proplists:proplist(), timeout()) ->
success | failure | {error, timeout | closed}.
ptty_alloc(ConnectionHandler, Channel, Options0, TimeOut) ->
TermData = backwards_compatible(Options0, []), % FIXME
{Width, PixWidth} = pty_default_dimensions(width, TermData),
{Height, PixHeight} = pty_default_dimensions(height, TermData),
pty_req(ConnectionHandler, Channel,
proplists:get_value(term, TermData, os:getenv("TERM", ?DEFAULT_TERMINAL)),
proplists:get_value(width, TermData, Width),
proplists:get_value(height, TermData, Height),
proplists:get_value(pixel_widh, TermData, PixWidth),
proplists:get_value(pixel_height, TermData, PixHeight),
proplists:get_value(pty_opts, TermData, []), TimeOut
).
%%--------------------------------------------------------------------
%% Not yet officialy supported! The following functions are part of the
%% initial contributed ssh application. They are untested. Do we want them?
%% Should they be documented and tested?
%%--------------------------------------------------------------------
window_change(ConnectionHandler, Channel, Width, Height) ->
window_change(ConnectionHandler, Channel, Width, Height, 0, 0).
window_change(ConnectionHandler, Channel, Width, Height,
PixWidth, PixHeight) ->
ssh_connection_handler:request(ConnectionHandler, Channel,
"window-change", false,
[?uint32(Width), ?uint32(Height),
?uint32(PixWidth), ?uint32(PixHeight)], 0).
signal(ConnectionHandler, Channel, Sig) ->
ssh_connection_handler:request(ConnectionHandler, Channel,
"signal", false, [?string(Sig)], 0).
exit_status(ConnectionHandler, Channel, Status) ->
ssh_connection_handler:request(ConnectionHandler, Channel,
"exit-status", false, [?uint32(Status)], 0).
%%--------------------------------------------------------------------
%%% Internal, that is, ssh application internal API
%%--------------------------------------------------------------------
%%%----------------------------------------------------------------
%%% Send data on a channel/connection as result of for example
%%% ssh_connection:send (executed in the ssh_connection_state machine)
%%%
channel_data(ChannelId, DataType, Data, Connection, From) when is_list(Data)->
channel_data(ChannelId, DataType, l2b(Data), Connection, From);
channel_data(ChannelId, DataType, Data,
#connection{channel_cache = Cache} = Connection,
From) ->
case ssh_channel:cache_lookup(Cache, ChannelId) of
#channel{remote_id = Id, sent_close = false} = Channel0 ->
{SendList, Channel} =
update_send_window(Channel0#channel{flow_control = From}, DataType,
Data, Connection),
Replies =
lists:map(fun({SendDataType, SendData}) ->
{connection_reply,
channel_data_msg(Id,
SendDataType,
SendData)}
end, SendList),
FlowCtrlMsgs = flow_control(Replies, Channel, Cache),
{Replies ++ FlowCtrlMsgs, Connection};
_ ->
{[{channel_request_reply,From,{error,closed}}], Connection}
end.
%%%----------------------------------------------------------------
%%% Handle the channel messages on behalf of the ssh_connection_handler
%%% state machine.
%%%
%%% Replies {Reply, UpdatedConnection}
%%%
handle_msg(#ssh_msg_channel_open_confirmation{recipient_channel = ChannelId,
sender_channel = RemoteId,
initial_window_size = WindowSz,
maximum_packet_size = PacketSz},
#connection{channel_cache = Cache} = Connection0, _) ->
#channel{remote_id = undefined} = Channel =
ssh_channel:cache_lookup(Cache, ChannelId),
ssh_channel:cache_update(Cache, Channel#channel{
remote_id = RemoteId,
recv_packet_size = max(32768, % rfc4254/5.2
min(PacketSz, Channel#channel.recv_packet_size)
),
send_window_size = WindowSz,
send_packet_size = PacketSz}),
reply_msg(Channel, Connection0, {open, ChannelId});
handle_msg(#ssh_msg_channel_open_failure{recipient_channel = ChannelId,
reason = Reason,
description = Descr,
lang = Lang},
#connection{channel_cache = Cache} = Connection0, _) ->
Channel = ssh_channel:cache_lookup(Cache, ChannelId),
ssh_channel:cache_delete(Cache, ChannelId),
reply_msg(Channel, Connection0, {open_error, Reason, Descr, Lang});
handle_msg(#ssh_msg_channel_success{recipient_channel = ChannelId}, Connection, _) ->
reply_msg(ChannelId, Connection, success);
handle_msg(#ssh_msg_channel_failure{recipient_channel = ChannelId}, Connection, _) ->
reply_msg(ChannelId, Connection, failure);
handle_msg(#ssh_msg_channel_eof{recipient_channel = ChannelId}, Connection, _) ->
reply_msg(ChannelId, Connection, {eof, ChannelId});
handle_msg(#ssh_msg_channel_close{recipient_channel = ChannelId},
#connection{channel_cache = Cache} = Connection0, _) ->
case ssh_channel:cache_lookup(Cache, ChannelId) of
#channel{sent_close = Closed, remote_id = RemoteId,
flow_control = FlowControl} = Channel ->
ssh_channel:cache_delete(Cache, ChannelId),
{CloseMsg, Connection} =
reply_msg(Channel, Connection0, {closed, ChannelId}),
ConnReplyMsgs =
case Closed of
true -> [];
false ->
RemoteCloseMsg = channel_close_msg(RemoteId),
[{connection_reply, RemoteCloseMsg}]
end,
%% if there was a send() in progress, make it fail
SendReplyMsgs =
case FlowControl of
undefined -> [];
From ->
[{flow_control, From, {error, closed}}]
end,
Replies = ConnReplyMsgs ++ CloseMsg ++ SendReplyMsgs,
{Replies, Connection};
undefined ->
{[], Connection0}
end;
handle_msg(#ssh_msg_channel_data{recipient_channel = ChannelId,
data = Data},
Connection, _) ->
channel_data_reply_msg(ChannelId, Connection, 0, Data);
handle_msg(#ssh_msg_channel_extended_data{recipient_channel = ChannelId,
data_type_code = DataType,
data = Data},
Connection, _) ->
channel_data_reply_msg(ChannelId, Connection, DataType, Data);
handle_msg(#ssh_msg_channel_window_adjust{recipient_channel = ChannelId,
bytes_to_add = Add},
#connection{channel_cache = Cache} = Connection, _) ->
#channel{send_window_size = Size, remote_id = RemoteId} =
Channel0 = ssh_channel:cache_lookup(Cache, ChannelId),
{SendList, Channel} = %% TODO: Datatype 0 ?
update_send_window(Channel0#channel{send_window_size = Size + Add},
0, undefined, Connection),
Replies = lists:map(fun({Type, Data}) ->
{connection_reply, channel_data_msg(RemoteId, Type, Data)}
end, SendList),
FlowCtrlMsgs = flow_control(Channel, Cache),
{Replies ++ FlowCtrlMsgs, Connection};
handle_msg(#ssh_msg_channel_open{channel_type = "session" = Type,
sender_channel = RemoteId,
initial_window_size = WindowSz,
maximum_packet_size = PacketSz},
#connection{options = SSHopts} = Connection0,
server) ->
MinAcceptedPackSz =
?GET_OPT(minimal_remote_max_packet_size, SSHopts),
if
MinAcceptedPackSz =< PacketSz ->
try setup_session(Connection0, RemoteId,
Type, WindowSz, PacketSz) of
Result ->
Result
catch _:_ ->
FailMsg = channel_open_failure_msg(RemoteId,
?SSH_OPEN_CONNECT_FAILED,
"Connection refused", "en"),
{[{connection_reply, FailMsg}], Connection0}
end;
MinAcceptedPackSz > PacketSz ->
FailMsg = channel_open_failure_msg(RemoteId,
?SSH_OPEN_ADMINISTRATIVELY_PROHIBITED,
lists:concat(["Maximum packet size below ",MinAcceptedPackSz,
" not supported"]), "en"),
{[{connection_reply, FailMsg}], Connection0}
end;
handle_msg(#ssh_msg_channel_open{channel_type = "session",
sender_channel = RemoteId},
Connection,
client) ->
%% Client implementations SHOULD reject any session channel open
%% requests to make it more difficult for a corrupt server to attack the
%% client. See See RFC 4254 6.1.
FailMsg = channel_open_failure_msg(RemoteId,
?SSH_OPEN_CONNECT_FAILED,
"Connection refused", "en"),
{[{connection_reply, FailMsg}], Connection};
handle_msg(#ssh_msg_channel_open{sender_channel = RemoteId}, Connection, _) ->
FailMsg = channel_open_failure_msg(RemoteId,
?SSH_OPEN_ADMINISTRATIVELY_PROHIBITED,
"Not allowed", "en"),
{[{connection_reply, FailMsg}], Connection};
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "exit-status",
data = Data},
Connection, _) ->
<<?UINT32(Status)>> = Data,
reply_msg(ChannelId, Connection, {exit_status, ChannelId, Status});
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "exit-signal",
want_reply = false,
data = Data},
#connection{channel_cache = Cache} = Connection0, _) ->
<<?DEC_BIN(SigName, _SigLen),
?BOOLEAN(_Core),
?DEC_BIN(Err, _ErrLen),
?DEC_BIN(Lang, _LangLen)>> = Data,
Channel = ssh_channel:cache_lookup(Cache, ChannelId),
RemoteId = Channel#channel.remote_id,
{Reply, Connection} = reply_msg(Channel, Connection0,
{exit_signal, ChannelId,
binary_to_list(SigName),
binary_to_list(Err),
binary_to_list(Lang)}),
CloseMsg = channel_close_msg(RemoteId),
{[{connection_reply, CloseMsg}|Reply], Connection};
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "xon-xoff",
want_reply = false,
data = Data},
Connection, _) ->
<<?BOOLEAN(CDo)>> = Data,
reply_msg(ChannelId, Connection, {xon_xoff, ChannelId, CDo=/= 0});
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "window-change",
want_reply = false,
data = Data},
Connection0, _) ->
<<?UINT32(Width),?UINT32(Height),
?UINT32(PixWidth), ?UINT32(PixHeight)>> = Data,
reply_msg(ChannelId, Connection0, {window_change, ChannelId,
Width, Height,
PixWidth, PixHeight});
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "signal",
data = Data},
Connection0, _) ->
<<?DEC_BIN(SigName, _SigLen)>> = Data,
reply_msg(ChannelId, Connection0, {signal, ChannelId,
binary_to_list(SigName)});
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "subsystem",
want_reply = WantReply,
data = Data},
#connection{channel_cache = Cache} = Connection, server) ->
<<?DEC_BIN(SsName,_SsLen)>> = Data,
#channel{remote_id = RemoteId} = Channel0 =
ssh_channel:cache_lookup(Cache, ChannelId),
ReplyMsg = {subsystem, ChannelId, WantReply, binary_to_list(SsName)},
try
{ok, Pid} = start_subsystem(SsName, Connection, Channel0, ReplyMsg),
erlang:monitor(process, Pid),
Channel = Channel0#channel{user = Pid},
ssh_channel:cache_update(Cache, Channel),
Reply = {connection_reply,
channel_success_msg(RemoteId)},
{[Reply], Connection}
catch
_:_ ->
ErrorReply = {connection_reply, channel_failure_msg(RemoteId)},
{[ErrorReply], Connection}
end;
handle_msg(#ssh_msg_channel_request{request_type = "subsystem"},
Connection, client) ->
%% The client SHOULD ignore subsystem requests. See RFC 4254 6.5.
{[], Connection};
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "pty-req",
want_reply = WantReply,
data = Data},
Connection, server) ->
<<?DEC_BIN(BTermName,_TermLen),
?UINT32(Width),?UINT32(Height),
?UINT32(PixWidth), ?UINT32(PixHeight),
Modes/binary>> = Data,
TermName = binary_to_list(BTermName),
PtyRequest = {TermName, Width, Height,
PixWidth, PixHeight, decode_pty_opts(Modes)},
handle_cli_msg(Connection, ChannelId,
{pty, ChannelId, WantReply, PtyRequest});
handle_msg(#ssh_msg_channel_request{request_type = "pty-req"},
Connection, client) ->
%% The client SHOULD ignore pty requests. See RFC 4254 6.2.
{[], Connection};
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "shell",
want_reply = WantReply},
Connection, server) ->
handle_cli_msg(Connection, ChannelId,
{shell, ChannelId, WantReply});
handle_msg(#ssh_msg_channel_request{request_type = "shell"},
Connection, client) ->
%% The client SHOULD ignore shell requests. See RFC 4254 6.5.
{[], Connection};
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "exec",
want_reply = WantReply,
data = Data},
Connection, server) ->
<<?DEC_BIN(Command, _Len)>> = Data,
handle_cli_msg(Connection, ChannelId,
{exec, ChannelId, WantReply, binary_to_list(Command)});
handle_msg(#ssh_msg_channel_request{request_type = "exec"},
Connection, client) ->
%% The client SHOULD ignore exec requests. See RFC 4254 6.5.
{[], Connection};
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = "env",
want_reply = WantReply,
data = Data},
Connection, server) ->
<<?DEC_BIN(Var,_VarLen), ?DEC_BIN(Value,_ValLen)>> = Data,
handle_cli_msg(Connection, ChannelId,
{env, ChannelId, WantReply, Var, Value});
handle_msg(#ssh_msg_channel_request{request_type = "env"},
Connection, client) ->
%% The client SHOULD ignore env requests.
{[], Connection};
handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = _Other,
want_reply = WantReply},
#connection{channel_cache = Cache} = Connection, _) ->
if WantReply == true ->
case ssh_channel:cache_lookup(Cache, ChannelId) of
#channel{remote_id = RemoteId} ->
FailMsg = channel_failure_msg(RemoteId),
{[{connection_reply, FailMsg}], Connection};
undefined -> %% Chanel has been closed
{[], Connection}
end;
true ->
{[], Connection}
end;
handle_msg(#ssh_msg_global_request{name = _Type,
want_reply = WantReply,
data = _Data}, Connection, _) ->
if WantReply == true ->
FailMsg = request_failure_msg(),
{[{connection_reply, FailMsg}], Connection};
true ->
{[], Connection}
end;
handle_msg(#ssh_msg_request_failure{},
#connection{requests = [{_, From} | Rest]} = Connection, _) ->
{[{channel_request_reply, From, {failure, <<>>}}],
Connection#connection{requests = Rest}};
handle_msg(#ssh_msg_request_success{data = Data},
#connection{requests = [{_, From} | Rest]} = Connection, _) ->
{[{channel_request_reply, From, {success, Data}}],
Connection#connection{requests = Rest}};
handle_msg(#ssh_msg_disconnect{code = Code,
description = Description},
Connection, _) ->
{disconnect, {Code, Description}, handle_stop(Connection)}.
%%%----------------------------------------------------------------
%%% Returns pending responses to be delivered to the peer when a
%%% Channel/Connection closes
%%%
handle_stop(#connection{channel_cache = Cache} = Connection0) ->
{Connection, Replies} =
ssh_channel:cache_foldl(
fun(Channel, {Connection1, Acc}) ->
{Reply, Connection2} =
reply_msg(Channel, Connection1,
{closed, Channel#channel.local_id}),
{Connection2, Reply ++ Acc}
end, {Connection0, []}, Cache),
ssh_channel:cache_delete(Cache),
{Replies, Connection}.
%%%----------------------------------------------------------------
%%% channel_*_msg(...)
%%% Returns a #ssh_msg_....{} for channel operations.
%%%
channel_adjust_window_msg(ChannelId, Bytes) ->
#ssh_msg_channel_window_adjust{recipient_channel = ChannelId,
bytes_to_add = Bytes}.
channel_close_msg(ChannelId) ->
#ssh_msg_channel_close {recipient_channel = ChannelId}.
channel_data_msg(ChannelId, 0, Data) ->
#ssh_msg_channel_data{recipient_channel = ChannelId,
data = Data};
channel_data_msg(ChannelId, Type, Data) ->
#ssh_msg_channel_extended_data{recipient_channel = ChannelId,
data_type_code = Type,
data = Data}.
channel_eof_msg(ChannelId) ->
#ssh_msg_channel_eof{recipient_channel = ChannelId}.
channel_failure_msg(ChannelId) ->
#ssh_msg_channel_failure{recipient_channel = ChannelId}.
channel_open_msg(Type, ChannelId, WindowSize, MaxPacketSize, Data) ->
#ssh_msg_channel_open{channel_type = Type,
sender_channel = ChannelId,
initial_window_size = WindowSize,
maximum_packet_size = MaxPacketSize,
data = Data
}.
channel_open_confirmation_msg(RemoteId, LID, WindowSize, PacketSize) ->
#ssh_msg_channel_open_confirmation{recipient_channel = RemoteId,
sender_channel = LID,
initial_window_size = WindowSize,
maximum_packet_size = PacketSize}.
channel_open_failure_msg(RemoteId, Reason, Description, Lang) ->
#ssh_msg_channel_open_failure{recipient_channel = RemoteId,
reason = Reason,
description = Description,
lang = Lang}.
channel_status_msg({success, ChannelId}) ->
channel_success_msg(ChannelId);
channel_status_msg({failure, ChannelId}) ->
channel_failure_msg(ChannelId).
channel_request_msg(ChannelId, Type, WantReply, Data) ->
#ssh_msg_channel_request{recipient_channel = ChannelId,
request_type = Type,
want_reply = WantReply,
data = Data}.
channel_success_msg(ChannelId) ->
#ssh_msg_channel_success{recipient_channel = ChannelId}.
%%%----------------------------------------------------------------
%%% request_*_msg(...)
%%% Returns a #ssh_msg_....{} for request responses.
%%%
request_failure_msg() ->
#ssh_msg_request_failure{}.
request_success_msg(Data) ->
#ssh_msg_request_success{data = Data}.
%%%----------------------------------------------------------------
%%%
%%%
bind(IP, Port, ChannelPid, Connection) ->
Binds = [{{IP, Port}, ChannelPid}
| lists:keydelete({IP, Port}, 1,
Connection#connection.port_bindings)],
Connection#connection{port_bindings = Binds}.
unbind(IP, Port, Connection) ->
Connection#connection{
port_bindings =
lists:keydelete({IP, Port}, 1,
Connection#connection.port_bindings)}.
unbind_channel(ChannelPid, Connection) ->
Binds = [{Bind, ChannelP} || {Bind, ChannelP}
<- Connection#connection.port_bindings,
ChannelP =/= ChannelPid],
Connection#connection{port_bindings = Binds}.
bound_channel(IP, Port, Connection) ->
case lists:keysearch({IP, Port}, 1, Connection#connection.port_bindings) of
{value, {{IP, Port}, ChannelPid}} -> ChannelPid;
_ -> undefined
end.
encode_ip(Addr) when is_tuple(Addr) ->
case catch inet_parse:ntoa(Addr) of
{'EXIT',_} -> false;
A -> A
end;
encode_ip(Addr) when is_list(Addr) ->
case inet_parse:address(Addr) of
{ok, _} -> Addr;
Error ->
case inet:getaddr(Addr, inet) of
{ok, A} ->
inet_parse:ntoa(A);
Error -> false
end
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%
%%% Internal functions
%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%----------------------------------------------------------------
%%% Create the channel data when an ssh_msg_open_channel message
%%% of "session" typ is handled
%%%
setup_session(#connection{channel_cache = Cache,
channel_id_seed = NewChannelID
} = C,
RemoteId, Type, WindowSize, PacketSize) ->
NextChannelID = NewChannelID + 1,
Channel =
#channel{type = Type,
sys = "ssh",
local_id = NewChannelID,
recv_window_size = ?DEFAULT_WINDOW_SIZE,
recv_packet_size = ?DEFAULT_PACKET_SIZE,
send_window_size = WindowSize,
send_packet_size = PacketSize,
send_buf = queue:new(),
remote_id = RemoteId
},
ssh_channel:cache_update(Cache, Channel),
OpenConfMsg = channel_open_confirmation_msg(RemoteId, NewChannelID,
?DEFAULT_WINDOW_SIZE,
?DEFAULT_PACKET_SIZE),
Reply = {connection_reply, OpenConfMsg},
{[Reply], C#connection{channel_id_seed = NextChannelID}}.
%%%----------------------------------------------------------------
%%% Start a cli or subsystem
%%%
start_cli(#connection{options = Options,
cli_spec = CliSpec,
exec = Exec,
sub_system_supervisor = SubSysSup}, ChannelId) ->
case CliSpec of
no_cli ->
{error, cli_disabled};
{CbModule, Args} ->
start_channel(CbModule, ChannelId, Args, SubSysSup, Exec, Options)
end.
start_subsystem(BinName, #connection{options = Options,
sub_system_supervisor = SubSysSup},
#channel{local_id = ChannelId}, _ReplyMsg) ->
Name = binary_to_list(BinName),
case check_subsystem(Name, Options) of
{Callback, Opts} when is_atom(Callback), Callback =/= none ->
start_channel(Callback, ChannelId, Opts, SubSysSup, Options);
{Other, _} when Other =/= none ->
{error, legacy_option_not_supported}
end.
%%% Helpers for starting cli/subsystems
start_channel(Cb, Id, Args, SubSysSup, Opts) ->
start_channel(Cb, Id, Args, SubSysSup, undefined, Opts).
start_channel(Cb, Id, Args, SubSysSup, Exec, Opts) ->
ChannelSup = ssh_subsystem_sup:channel_supervisor(SubSysSup),
case max_num_channels_not_exceeded(ChannelSup, Opts) of
true ->
ssh_daemon_channel_sup:start_child(ChannelSup, Cb, Id, Args, Exec);
false ->
throw(max_num_channels_exceeded)
end.
max_num_channels_not_exceeded(ChannelSup, Opts) ->
MaxNumChannels = ?GET_OPT(max_channels, Opts),
NumChannels = length([x || {_,_,worker,[ssh_daemon_channel]} <-
supervisor:which_children(ChannelSup)]),
%% Note that NumChannels is BEFORE starting a new one
NumChannels < MaxNumChannels.
check_subsystem("sftp"= SsName, Options) ->
case ?GET_OPT(subsystems, Options) of
no_subsys -> % FIXME: Can 'no_subsys' ever be matched?
{SsName, {Cb, Opts}} = ssh_sftpd:subsystem_spec([]),
{Cb, Opts};
SubSystems ->
proplists:get_value(SsName, SubSystems, {none, []})
end;
check_subsystem(SsName, Options) ->
Subsystems = ?GET_OPT(subsystems, Options),
case proplists:get_value(SsName, Subsystems, {none, []}) of
Fun when is_function(Fun) ->
{Fun, []};
{_, _} = Value ->
Value
end.
%%%----------------------------------------------------------------
%%%
%%% Send-window handling
%%%
update_send_window(Channel, _, undefined,
#connection{channel_cache = Cache}) ->
do_update_send_window(Channel, Cache);
update_send_window(#channel{send_buf = SendBuffer} = Channel, DataType, Data,
#connection{channel_cache = Cache}) ->
do_update_send_window(Channel#channel{send_buf = queue:in({DataType, Data}, SendBuffer)},
Cache).
do_update_send_window(Channel0, Cache) ->
{SendMsgs, Channel} = get_window(Channel0, []),
ssh_channel:cache_update(Cache, Channel),
{SendMsgs, Channel}.
get_window(#channel{send_window_size = 0
} = Channel, Acc) ->
{lists:reverse(Acc), Channel};
get_window(#channel{send_packet_size = 0
} = Channel, Acc) ->
{lists:reverse(Acc), Channel};
get_window(#channel{send_buf = Buffer,
send_packet_size = PacketSize,
send_window_size = WindowSize0
} = Channel, Acc0) ->
case queue:out(Buffer) of
{{value, {_, Data} = Msg}, NewBuffer} ->
case handle_send_window(Msg, size(Data), PacketSize, WindowSize0, Acc0) of
{WindowSize, Acc, {_, <<>>}} ->
{lists:reverse(Acc), Channel#channel{send_window_size = WindowSize,
send_buf = NewBuffer}};
{WindowSize, Acc, Rest} ->
get_window(Channel#channel{send_window_size = WindowSize,
send_buf = queue:in_r(Rest, NewBuffer)}, Acc)
end;
{empty, NewBuffer} ->
{[], Channel#channel{send_buf = NewBuffer}}
end.
handle_send_window(Msg = {Type, Data}, Size, PacketSize, WindowSize, Acc) when Size =< WindowSize ->
case Size =< PacketSize of
true ->
{WindowSize - Size, [Msg | Acc], {Type, <<>>}};
false ->
<<Msg1:PacketSize/binary, Msg2/binary>> = Data,
{WindowSize - PacketSize, [{Type, Msg1} | Acc], {Type, Msg2}}
end;
handle_send_window({Type, Data}, _, PacketSize, WindowSize, Acc) when WindowSize =< PacketSize ->
<<Msg1:WindowSize/binary, Msg2/binary>> = Data,
{WindowSize - WindowSize, [{Type, Msg1} | Acc], {Type, Msg2}};
handle_send_window({Type, Data}, _, PacketSize, WindowSize, Acc) ->
<<Msg1:PacketSize/binary, Msg2/binary>> = Data,
{WindowSize - PacketSize, [{Type, Msg1} | Acc], {Type, Msg2}}.
%%%----------------------------------------------------------------
%%%
%%% Flow control
%%%
flow_control(Channel, Cache) ->
flow_control([window_adjusted], Channel, Cache).
flow_control([], Channel, Cache) ->
ssh_channel:cache_update(Cache, Channel),
[];
flow_control([_|_], #channel{flow_control = From,
send_buf = Buffer} = Channel, Cache) when From =/= undefined ->
case queue:is_empty(Buffer) of
true ->
ssh_channel:cache_update(Cache, Channel#channel{flow_control = undefined}),
[{flow_control, Cache, Channel, From, ok}];
false ->
[]
end;
flow_control(_,_,_) ->
[].
%%%----------------------------------------------------------------
%%%
%%% Pseudo terminal stuff
%%%
pty_req(ConnectionHandler, Channel, Term, Width, Height,
PixWidth, PixHeight, PtyOpts, TimeOut) ->
ssh_connection_handler:request(ConnectionHandler,
Channel, "pty-req", true,
[?string(Term),
?uint32(Width), ?uint32(Height),
?uint32(PixWidth),?uint32(PixHeight),
encode_pty_opts(PtyOpts)], TimeOut).
pty_default_dimensions(Dimension, TermData) ->
case proplists:get_value(Dimension, TermData, 0) of
N when is_integer(N), N > 0 ->
{N, 0};
_ ->
PixelDim = list_to_atom("pixel_" ++ atom_to_list(Dimension)),
case proplists:get_value(PixelDim, TermData, 0) of
N when is_integer(N), N > 0 ->
{0, N};
_ ->
{?TERMINAL_WIDTH, 0}
end
end.
encode_pty_opts(Opts) ->
Bin = list_to_binary(encode_pty_opts2(Opts)),
<<?STRING(Bin)>>.
encode_pty_opts2([]) ->
[?TTY_OP_END];
encode_pty_opts2([{vintr,Value} | Opts]) ->
[?VINTR, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vquit,Value} | Opts]) ->
[?VQUIT, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{verase,Value} | Opts]) ->
[?VERASE, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vkill,Value} | Opts]) ->
[?VKILL, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{veof,Value} | Opts]) ->
[?VEOF, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{veol,Value} | Opts]) ->
[?VEOL, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{veol2,Value} | Opts]) ->
[?VEOL2, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vstart,Value} | Opts]) ->
[?VSTART, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vstop,Value} | Opts]) ->
[?VSTOP, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vsusp,Value} | Opts]) ->
[?VSUSP, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vdsusp,Value} | Opts]) ->
[?VDSUSP, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vreprint,Value} | Opts]) ->
[?VREPRINT, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vwerase,Value} | Opts]) ->
[ ?VWERASE, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vlnext,Value} | Opts]) ->
[?VLNEXT, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vflush,Value} | Opts]) ->
[?VFLUSH, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vswtch,Value} | Opts]) ->
[?VSWTCH, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vstatus,Value} | Opts]) ->
[?VSTATUS, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{vdiscard,Value} | Opts]) ->
[?VDISCARD, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{ignpar,Value} | Opts]) ->
[?IGNPAR, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{parmrk,Value} | Opts]) ->
[?PARMRK, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{inpck,Value} | Opts]) ->
[?INPCK, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{istrip,Value} | Opts]) ->
[?ISTRIP, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{inlcr,Value} | Opts]) ->
[?INLCR, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{igncr,Value} | Opts]) ->
[?IGNCR, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{icrnl,Value} | Opts]) ->
[?ICRNL, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{iuclc,Value} | Opts]) ->
[?IUCLC, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{ixon,Value} | Opts]) ->
[?IXON, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{ixany,Value} | Opts]) ->
[?IXANY, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{ixoff,Value} | Opts]) ->
[?IXOFF, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{imaxbel,Value} | Opts]) ->
[?IMAXBEL, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{isig,Value} | Opts]) ->
[?ISIG, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{icanon,Value} | Opts]) ->
[?ICANON, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{xcase,Value} | Opts]) ->
[?XCASE, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{echo,Value} | Opts]) ->
[?ECHO, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{echoe,Value} | Opts]) ->
[?ECHOE, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{echok,Value} | Opts]) ->
[?ECHOK, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{echonl,Value} | Opts]) ->
[?ECHONL, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{noflsh,Value} | Opts]) ->
[?NOFLSH, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{tostop,Value} | Opts]) ->
[?TOSTOP, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{iexten,Value} | Opts]) ->
[?IEXTEN, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{echoctl,Value} | Opts]) ->
[?ECHOCTL, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{echoke,Value} | Opts]) ->
[?ECHOKE, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{pendin,Value} | Opts]) ->
[?PENDIN, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{opost,Value} | Opts]) ->
[?OPOST, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{olcuc,Value} | Opts]) ->
[?OLCUC, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{onlcr,Value} | Opts]) ->
[?ONLCR, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{ocrnl,Value} | Opts]) ->
[?OCRNL, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{onocr,Value} | Opts]) ->
[?ONOCR, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{onlret,Value} | Opts]) ->
[?ONLRET, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{cs7,Value} | Opts]) ->
[?CS7, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{cs8,Value} | Opts]) ->
[?CS8, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{parenb,Value} | Opts]) ->
[?PARENB, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{parodd,Value} | Opts]) ->
[?PARODD, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{tty_op_ispeed,Value} | Opts]) ->
[?TTY_OP_ISPEED, ?uint32(Value) | encode_pty_opts2(Opts)];
encode_pty_opts2([{tty_op_ospeed,Value} | Opts]) ->
[?TTY_OP_OSPEED, ?uint32(Value) | encode_pty_opts2(Opts)].
decode_pty_opts(<<>>) ->
[];
decode_pty_opts(<<0, 0, 0, 0>>) ->
[];
decode_pty_opts(<<?DEC_BIN(Modes,_Len)>>) ->
decode_pty_opts2(Modes);
decode_pty_opts(Binary) ->
decode_pty_opts2(Binary).
decode_pty_opts2(<<?TTY_OP_END>>) ->
[];
decode_pty_opts2(<<Code, ?UINT32(Value), Tail/binary>>) ->
Op = case Code of
?VINTR -> vintr;
?VQUIT -> vquit;
?VERASE -> verase;
?VKILL -> vkill;
?VEOF -> veof;
?VEOL -> veol;
?VEOL2 -> veol2;
?VSTART -> vstart;
?VSTOP -> vstop;
?VSUSP -> vsusp;
?VDSUSP -> vdsusp;
?VREPRINT -> vreprint;
?VWERASE -> vwerase;
?VLNEXT -> vlnext;
?VFLUSH -> vflush;
?VSWTCH -> vswtch;
?VSTATUS -> vstatus;
?VDISCARD -> vdiscard;
?IGNPAR -> ignpar;
?PARMRK -> parmrk;
?INPCK -> inpck;
?ISTRIP -> istrip;
?INLCR -> inlcr;
?IGNCR -> igncr;
?ICRNL -> icrnl;
?IUCLC -> iuclc;
?IXON -> ixon;
?IXANY -> ixany;
?IXOFF -> ixoff;
?IMAXBEL -> imaxbel;
?ISIG -> isig;
?ICANON -> icanon;
?XCASE -> xcase;
?ECHO -> echo;
?ECHOE -> echoe;
?ECHOK -> echok;
?ECHONL -> echonl;
?NOFLSH -> noflsh;
?TOSTOP -> tostop;
?IEXTEN -> iexten;
?ECHOCTL -> echoctl;
?ECHOKE -> echoke;
?PENDIN -> pendin;
?OPOST -> opost;
?OLCUC -> olcuc;
?ONLCR -> onlcr;
?OCRNL -> ocrnl;
?ONOCR -> onocr;
?ONLRET -> onlret;
?CS7 -> cs7;
?CS8 -> cs8;
?PARENB -> parenb;
?PARODD -> parodd;
?TTY_OP_ISPEED -> tty_op_ispeed;
?TTY_OP_OSPEED -> tty_op_ospeed;
_ -> Code
end,
[{Op, Value} | decode_pty_opts2(Tail)].
backwards_compatible([], Acc) ->
Acc;
backwards_compatible([{hight, Value} | Rest], Acc) ->
backwards_compatible(Rest, [{height, Value} | Acc]);
backwards_compatible([{pixel_hight, Value} | Rest], Acc) ->
backwards_compatible(Rest, [{height, Value} | Acc]);
backwards_compatible([Value| Rest], Acc) ->
backwards_compatible(Rest, [ Value | Acc]).
%%%----------------------------------------------------------------
%%%
%%% Common part of handling channel messages meant for a cli (like "env", "exec" etc)
%%% Called at the finnish of handle_msg(#ssh_msg_channel_request,...)
%%%
handle_cli_msg(C0, ChId, Reply0) ->
Cache = C0#connection.channel_cache,
Ch0 = ssh_channel:cache_lookup(Cache, ChId),
case Ch0#channel.user of
undefined ->
case (catch start_cli(C0, ChId)) of
{ok, Pid} ->
erlang:monitor(process, Pid),
Ch = Ch0#channel{user = Pid},
ssh_channel:cache_update(Cache, Ch),
reply_msg(Ch, C0, Reply0);
_Other ->
Reply = {connection_reply, channel_failure_msg(Ch0#channel.remote_id)},
{[Reply], C0}
end;
_ ->
reply_msg(Ch0, C0, Reply0)
end.
%%%----------------------------------------------------------------
%%%
%%% Request response handling on return to the calling ssh_connection_handler
%%% state machine.
%%%
channel_data_reply_msg(ChannelId, Connection, DataType, Data) ->
case ssh_channel:cache_lookup(Connection#connection.channel_cache, ChannelId) of
#channel{recv_window_size = Size} = Channel ->
WantedSize = Size - size(Data),
ssh_channel:cache_update(Connection#connection.channel_cache,
Channel#channel{recv_window_size = WantedSize}),
reply_msg(Channel, Connection, {data, ChannelId, DataType, Data});
undefined ->
{[], Connection}
end.
reply_msg(ChId, C, Reply) when is_integer(ChId) ->
reply_msg(ssh_channel:cache_lookup(C#connection.channel_cache, ChId), C, Reply);
reply_msg(Channel, Connection, {open, _} = Reply) ->
request_reply_or_data(Channel, Connection, Reply);
reply_msg(Channel, Connection, {open_error, _, _, _} = Reply) ->
request_reply_or_data(Channel, Connection, Reply);
reply_msg(Channel, Connection, success = Reply) ->
request_reply_or_data(Channel, Connection, Reply);
reply_msg(Channel, Connection, failure = Reply) ->
request_reply_or_data(Channel, Connection, Reply);
reply_msg(Channel, Connection, {closed, _} = Reply) ->
request_reply_or_data(Channel, Connection, Reply);
reply_msg(undefined, Connection, _Reply) ->
{[], Connection};
reply_msg(#channel{user = ChannelPid}, Connection, Reply) ->
{[{channel_data, ChannelPid, Reply}], Connection}.
request_reply_or_data(#channel{local_id = ChannelId, user = ChannelPid},
#connection{requests = Requests} =
Connection, Reply) ->
case lists:keysearch(ChannelId, 1, Requests) of
{value, {ChannelId, From}} ->
{[{channel_request_reply, From, Reply}],
Connection#connection{requests =
lists:keydelete(ChannelId, 1, Requests)}};
false when (Reply == success) or (Reply == failure) ->
{[], Connection};
false ->
{[{channel_data, ChannelPid, Reply}], Connection}
end.
%%%----------------------------------------------------------------
%%% l(ist)2b(inary)
%%%
l2b(L) when is_integer(hd(L)) ->
try list_to_binary(L)
of
B -> B
catch
_:_ ->
unicode:characters_to_binary(L)
end;
l2b([H|T]) ->
<< (l2b(H))/binary, (l2b(T))/binary >>;
l2b(B) when is_binary(B) ->
B;
l2b([]) ->
<<>>.