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ssh: Fix keepalive response stealing channel open requests #11205

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ssh: Fix keepalive response stealing channel open requests #11205

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64 changes: 39 additions & 25 deletions lib/ssh/src/ssh_connection.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -1291,36 +1291,50 @@ handle_msg(#ssh_msg_global_request{name = _Type,
end;

handle_msg(#ssh_msg_request_failure{},
#connection{requests = [{_, From} | Rest]} = Connection, _, _SSH) ->
{[{channel_request_reply, From, {failure, <<>>}}],
Connection#connection{requests = Rest}};

handle_msg(#ssh_msg_request_failure{},
#connection{requests = [{_, From,_} | Rest]} = Connection, _, _SSH) ->
{[{channel_request_reply, From, {failure, <<>>}}],
Connection#connection{requests = Rest}};

handle_msg(#ssh_msg_request_success{data = Data},
#connection{requests = [{_, From} | Rest]} = Connection, _, _SSH) ->
{[{channel_request_reply, From, {success, Data}}],
Connection#connection{requests = Rest}};
#connection{requests = Requests} = Connection, _, _SSH) ->
case take_global_request(Requests) of
{{_, From}, Rest} ->
{[{channel_request_reply, From, {failure, <<>>}}],
Connection#connection{requests = Rest}};
{{_, From, _}, Rest} ->
{[{channel_request_reply, From, {failure, <<>>}}],
Connection#connection{requests = Rest}};
false ->
{[], Connection}
end;

handle_msg(#ssh_msg_request_success{data = Data},
#connection{requests = [{_, From, Fun} | Rest]} = Connection0, _, _SSH) ->
Connection = Fun({success,Data}, Connection0),
{[{channel_request_reply, From, {success, Data}}],
Connection#connection{requests = Rest}};

%% alive responses
handle_msg(#ssh_msg_request_success{},
#connection{requests = []} = Connection, _, _SSH) ->
{[], Connection};
#connection{requests = Requests} = Connection0, _, _SSH) ->
case take_global_request(Requests) of
{{_, From}, Rest} ->
{[{channel_request_reply, From, {success, Data}}],
Connection0#connection{requests = Rest}};
{{_, From, Fun}, Rest} ->
Connection = Fun({success, Data}, Connection0),
{[{channel_request_reply, From, {success, Data}}],
Connection#connection{requests = Rest}};
false ->
{[], Connection0}
end.

handle_msg(#ssh_msg_request_failure{},
#connection{requests = []} = Connection, _, _SSH) ->
{[], Connection}.


%%%----------------------------------------------------------------
%%% Find and remove the first global request entry (keyed by reference)
%%% from the requests list, skipping channel entries (keyed by integer).
%%% Returns {Entry, RemainingList} or false.
%%%
take_global_request([]) ->
false;
take_global_request([{Ref, _} = E | Rest]) when is_reference(Ref) ->
{E, Rest};
take_global_request([{Ref, _, _} = E | Rest]) when is_reference(Ref) ->
{E, Rest};
take_global_request([H | T]) ->
case take_global_request(T) of
{E, Rest} -> {E, [H | Rest]};
false -> false
end.

%%%----------------------------------------------------------------
%%% Returns pending responses to be delivered to the peer when a
Expand Down
4 changes: 3 additions & 1 deletion lib/ssh/src/ssh_connection_handler.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -2105,6 +2105,8 @@ get_repl({channel_data,undefined,_Data}, Acc) ->
get_repl({channel_data,Pid,Data}, Acc) ->
Pid ! {ssh_cm, self(), Data},
Acc;
get_repl({channel_request_reply,undefined,_Data}, Acc) ->
Acc;
get_repl({channel_request_reply,From,Data}, {CallRepls,S}) ->
{[{reply,From,Data}|CallRepls], S};
get_repl({flow_control,Cache,Channel,From,Msg}, {CallRepls,S}) ->
Expand Down Expand Up @@ -2226,7 +2228,7 @@ triggered_alive(StateName, D0 = #data{},
{stop, Shutdown, D};
_ ->
D = send_msg({ssh_msg_global_request,"keepalive@erlang.org", true, <<>>},
D0),
add_request(fun(_,Conn) -> Conn end, make_ref(), undefined, D0)),
Ssh = D#data.ssh_params,
Now = erlang:monotonic_time(milli_seconds),
Ssh1 = Ssh#ssh{alive_probes_sent = SentProbes + 1,
Expand Down
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