Merge branch 'ia/ssh/sending-large-data-and-eof/OTP-10467'

* ia/ssh/sending-large-data-and-eof/OTP-10467:
  ssh: Make test case platform independant
  ssh: ssh_connection:channel_data() and send_eof() now return {error, closed} for closed or invalid channels.
  ssh: Ensure that all data is sent before ssh:send returns.
  ssh: add test suite for testing channel send/receive behavior.

7 files changed, 452 insertions, 39 deletions

diff --git a/lib/ssh/doc/src/ssh_connection.xml b/lib/ssh/doc/src/ssh_connection.xml
index 9942306b93..a9ae13d556 100644
--- a/lib/ssh/doc/src/ssh_connection.xml
+++ b/lib/ssh/doc/src/ssh_connection.xml
@@ -196,7 +196,7 @@
        <name>send(ConnectionRef, ChannelId, Data, Timeout) -></name>
        <name>send(ConnectionRef, ChannelId, Type, Data) -></name>
        <name>send(ConnectionRef, ChannelId, Type, Data, TimeOut) ->
-       ok | {error, timeout}</name>
+       ok | {error, timeout} | {error, closed}</name>
        <fsummary>Sends channel data </fsummary>
        <type>
 	<v> ConnectionRef = ssh_connection_ref() </v>
@@ -212,7 +212,7 @@
      </func>
      
      <func>
-       <name>send_eof(ConnectionRef, ChannelId) -> ok </name>
+       <name>send_eof(ConnectionRef, ChannelId) -> ok | {error, closed}</name>
        <fsummary>Sends eof on the channel <c>ChannelId</c>.  </fsummary>
        <type>
 	<v> ConnectionRef = ssh_connection_ref() </v>
diff --git a/lib/ssh/src/ssh_connection.erl b/lib/ssh/src/ssh_connection.erl
index e3b8ebfb79..240d7f70d1 100644
--- a/lib/ssh/src/ssh_connection.erl
+++ b/lib/ssh/src/ssh_connection.erl
@@ -318,21 +318,22 @@ channel_data(ChannelId, DataType, Data,
 	     From) ->
     
     case ssh_channel:cache_lookup(Cache, ChannelId) of
-	#channel{remote_id = Id} = Channel0 ->
-	    {SendList, Channel} = update_send_window(Channel0, DataType, 
+	#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, ConnectionPid, 
-				       channel_data_msg(Id, 
-							SendDataType, 
-							SendData)}
+				  {connection_reply, ConnectionPid,
+				   channel_data_msg(Id,
+						    SendDataType,
+						    SendData)}
 			  end, SendList),
 	    FlowCtrlMsgs = flow_control(Replies, 
-					Channel#channel{flow_control = From}, 
+					Channel,
 					Cache),
 	    {{replies, Replies ++ FlowCtrlMsgs}, Connection};
-	undefined ->
+	_ ->
+	    gen_server:reply(From, {error, closed}),
 	    {noreply, Connection}
     end.
 
@@ -386,20 +387,30 @@ handle_msg(#ssh_msg_channel_close{recipient_channel = ChannelId},
 	   ConnectionPid, _) ->
 
 	case ssh_channel:cache_lookup(Cache, ChannelId) of
-	    #channel{sent_close = Closed, remote_id = RemoteId} = Channel ->
+		#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 ->
-			{{replies, [CloseMsg]}, Connection};
+					true -> [];
 		    false ->
 			RemoteCloseMsg = channel_close_msg(RemoteId),
-			{{replies, 
-			  [{connection_reply, 
-				      ConnectionPid, RemoteCloseMsg},
-			   CloseMsg]}, Connection}
-		end;
+						[{connection_reply, ConnectionPid, 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, Replies}, Connection};
+
 	    undefined ->
 		{{replies, []}, Connection0}
 	end;
@@ -1126,13 +1137,13 @@ flow_control(Channel, Cache) ->
 flow_control([], Channel, Cache) ->
     ssh_channel:cache_update(Cache, Channel),
     [];
-flow_control([_|_], #channel{flow_control = From} = Channel, Cache) ->
-    case From of
-	undefined ->
-	    [];
-	_ ->
-	    [{flow_control, Cache,  Channel, From, ok}]
-    end.
+
+flow_control([_|_], #channel{flow_control = From,
+							 send_buf = []} = Channel, Cache) when From =/= undefined ->
+	[{flow_control, Cache, Channel, From, ok}];
+flow_control(_,_,_) ->
+	[].
+
 
 encode_pty_opts(Opts) ->
     Bin = list_to_binary(encode_pty_opts2(Opts)),
diff --git a/lib/ssh/src/ssh_connection_manager.erl b/lib/ssh/src/ssh_connection_manager.erl
index e53cd4f4f7..af521b77e4 100644
--- a/lib/ssh/src/ssh_connection_manager.erl
+++ b/lib/ssh/src/ssh_connection_manager.erl
@@ -163,7 +163,7 @@ send(ConnectionManager, ChannelId, Type, Data, Timeout) ->
     call(ConnectionManager, {data, ChannelId, Type, Data}, Timeout).
 
 send_eof(ConnectionManager, ChannelId) ->
-    cast(ConnectionManager, {eof, ChannelId}).
+    call(ConnectionManager, {eof, ChannelId}).
 
 %%====================================================================
 %% gen_server callbacks
@@ -295,6 +295,18 @@ handle_call({data, ChannelId, Type, Data}, From,
     channel_data(ChannelId, Type, Data, Connection0, ConnectionPid, From,
 		 State);
 
+handle_call({eof, ChannelId}, _From,
+			#state{connection = Pid, connection_state =
+					   #connection{channel_cache = Cache}} = State) ->
+	case ssh_channel:cache_lookup(Cache, ChannelId) of
+		#channel{remote_id = Id, sent_close = false} ->
+			send_msg({connection_reply, Pid,
+					  ssh_connection:channel_eof_msg(Id)}),
+			{reply, ok, State};
+		_ ->
+			{reply, {error,closed}, State}
+	end;
+
 handle_call({connection_info, Options}, From, 
 	    #state{connection = Connection} = State) ->
     ssh_connection_handler:connection_info(Connection, From, Options),
@@ -453,18 +465,6 @@ handle_cast({adjust_window, ChannelId, Bytes},
     end,
     {noreply, State};
 
-handle_cast({eof, ChannelId}, 
-	    #state{connection = Pid, connection_state = 
-		   #connection{channel_cache = Cache}} = State) ->
-    case ssh_channel:cache_lookup(Cache, ChannelId) of			 
-	#channel{remote_id = Id} ->
-	    send_msg({connection_reply, Pid, 
-		      ssh_connection:channel_eof_msg(Id)}),
-	    {noreply, State};
-	undefined -> 
-	    {noreply, State}
-    end;
-
 handle_cast({success, ChannelId},  #state{connection = Pid} = State) ->
     Msg = ssh_connection:channel_success_msg(ChannelId),
     send_msg({connection_reply, Pid, Msg}),
@@ -614,6 +614,8 @@ do_send_msg({connection_reply, Pid, Data}) ->
     ssh_connection_handler:send(Pid, Msg);
 do_send_msg({flow_control, Cache, Channel, From, Msg}) ->
     ssh_channel:cache_update(Cache, Channel#channel{flow_control = undefined}),
+    gen_server:reply(From, Msg);
+do_send_msg({flow_control, From, Msg}) ->
     gen_server:reply(From, Msg).
 
 handle_request(ChannelPid, ChannelId, Type, Data, WantReply, From, 
diff --git a/lib/ssh/test/Makefile b/lib/ssh/test/Makefile
index 25072688ad..f5db31baee 100644
--- a/lib/ssh/test/Makefile
+++ b/lib/ssh/test/Makefile
@@ -36,7 +36,9 @@ MODULES= \
 	ssh_to_openssh_SUITE \
 	ssh_sftp_SUITE \
 	ssh_sftpd_SUITE \
-        ssh_sftpd_erlclient_SUITE
+	ssh_sftpd_erlclient_SUITE \
+	ssh_connection_SUITE \
+	ssh_echo_server
 
 HRL_FILES_NEEDED_IN_TEST= \
 	$(ERL_TOP)/lib/ssh/src/ssh.hrl \
diff --git a/lib/ssh/test/ssh_connection_SUITE.erl b/lib/ssh/test/ssh_connection_SUITE.erl
new file mode 100644
index 0000000000..43a899f974
--- /dev/null
+++ b/lib/ssh/test/ssh_connection_SUITE.erl
@@ -0,0 +1,312 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2008-2012. 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_connection_SUITE).
+
+-include_lib("common_test/include/ct.hrl").
+
+-compile(export_all).
+
+-define(SSH_DEFAULT_PORT, 22).
+-define(EXEC_TIMEOUT, 10000).
+
+%%--------------------------------------------------------------------
+suite() ->
+    [{ct_hooks,[ts_install_cth]}].
+
+all() ->
+    [
+     {group, erlang_client},
+     interrupted_send
+    ].
+groups() ->
+    [{erlang_client, [], [simple_exec,
+			  small_cat,
+			  big_cat,
+			  send_after_exit
+			 ]}].
+
+%%--------------------------------------------------------------------
+
+init_per_suite(Config) ->
+    case catch crypto:start() of
+	ok ->
+	    Config;
+	_Else ->
+	    {skip, "Crypto could not be started!"}
+    end.
+
+end_per_suite(_Config) ->
+    crypto:stop(),
+    ok.
+%%--------------------------------------------------------------------
+init_per_group(erlang_client, Config) ->
+    case gen_tcp:connect("localhost", 22, []) of
+	{error,econnrefused} ->
+	    {skip,"No openssh deamon"};
+	_ ->
+	    Config
+     end;
+init_per_group(_, Config) ->
+    Config.
+
+end_per_group(_, Config) ->
+    Config.
+
+%%--------------------------------------------------------------------
+init_per_testcase(_TestCase, Config) ->
+    ssh:start(),
+    Config.
+
+end_per_testcase(_Config) ->
+    ssh:stop(),
+    ok.
+
+%%% TEST cases starts here.
+%%--------------------------------------------------------------------
+simple_exec(doc) ->
+    ["Simple openssh connectivity test for ssh_connection:exec"];
+
+simple_exec(Config) when is_list(Config) ->
+    ConnectionRef = ssh_test_lib:connect(?SSH_DEFAULT_PORT, [{silently_accept_hosts, true},
+							     {user_interaction, false}]),
+    {ok, ChannelId0} = ssh_connection:session_channel(ConnectionRef, infinity),
+    success = ssh_connection:exec(ConnectionRef, ChannelId0,
+				  "echo testing", infinity),
+
+    %% receive response to input
+    receive
+	{ssh_cm, ConnectionRef, {data, ChannelId0, 0, <<"testing\n">>}} ->
+	    ok
+    end,
+
+    %% receive close messages
+    receive
+	{ssh_cm, ConnectionRef, {eof, ChannelId0}} ->
+	    ok
+    end,
+    receive
+	{ssh_cm, ConnectionRef, {exit_status, ChannelId0, 0}} ->
+	    ok
+    end,
+    receive
+	{ssh_cm, ConnectionRef,{closed, ChannelId0}} ->
+	    ok
+    end.
+
+%%--------------------------------------------------------------------
+small_cat(doc) ->
+    ["Use 'cat' to echo small data block back to us."];
+
+small_cat(Config) when is_list(Config) ->
+    ConnectionRef = ssh_test_lib:connect(?SSH_DEFAULT_PORT, [{silently_accept_hosts, true},
+							     {user_interaction, false}]),
+    {ok, ChannelId0} = ssh_connection:session_channel(ConnectionRef, infinity),
+    success = ssh_connection:exec(ConnectionRef, ChannelId0,
+				  "cat", infinity),
+
+    Data = <<"I like spaghetti squash">>,
+    ok = ssh_connection:send(ConnectionRef, ChannelId0, Data),
+    ok = ssh_connection:send_eof(ConnectionRef, ChannelId0),
+
+    %% receive response to input
+    receive
+	{ssh_cm, ConnectionRef, {data, ChannelId0, 0, Data}} ->
+	    ok
+    end,
+
+    %% receive close messages
+    receive
+	{ssh_cm, ConnectionRef, {eof, ChannelId0}} ->
+	    ok
+    end,
+    receive
+	{ssh_cm, ConnectionRef, {exit_status, ChannelId0, 0}} ->
+	    ok
+    end,
+    receive
+	{ssh_cm, ConnectionRef,{closed, ChannelId0}} ->
+	    ok
+    end.
+
+%%--------------------------------------------------------------------
+big_cat(doc) ->
+    ["Use 'cat' to echo large data block back to us."];
+
+big_cat(Config) when is_list(Config) ->
+    ConnectionRef = ssh_test_lib:connect(?SSH_DEFAULT_PORT, [{silently_accept_hosts, true},
+							     {user_interaction, false}]),
+    {ok, ChannelId0} = ssh_connection:session_channel(ConnectionRef, infinity),
+    success = ssh_connection:exec(ConnectionRef, ChannelId0,
+				  "cat", infinity),
+
+    %% build 10MB binary
+    Data = << <<X:32>> || X <- lists:seq(1,2500000)>>,
+
+    %% pre-adjust receive window so the other end doesn't block
+    ssh_connection:adjust_window(ConnectionRef, ChannelId0, size(Data)),
+
+    test_server:format("sending ~p byte binary~n",[size(Data)]),
+    ok = ssh_connection:send(ConnectionRef, ChannelId0, Data, 10000),
+    ok = ssh_connection:send_eof(ConnectionRef, ChannelId0),
+
+    %% collect echoed data until eof
+    case big_cat_rx(ConnectionRef, ChannelId0) of
+	{ok, Data} ->
+	    ok;
+	{ok, Other} ->
+	    case size(Data) =:= size(Other) of
+		true ->
+		    test_server:format("received and sent data are same"
+				       "size but do not match~n",[]);
+		false ->
+		    test_server:format("sent ~p but only received ~p~n",
+				       [size(Data), size(Other)])
+	    end,
+	    ct:fail(receive_data_mismatch);
+	Else ->
+	    ct:fail(Else)
+    end,
+
+    %% receive close messages (eof already consumed)
+    receive
+	{ssh_cm, ConnectionRef, {exit_status, ChannelId0, 0}} ->
+	    ok
+    end,
+    receive
+	{ssh_cm, ConnectionRef,{closed, ChannelId0}} ->
+	    ok
+    end.
+
+big_cat_rx(ConnectionRef, ChannelId) ->
+    big_cat_rx(ConnectionRef, ChannelId, []).
+
+big_cat_rx(ConnectionRef, ChannelId, Acc) ->
+    receive
+	{ssh_cm, ConnectionRef, {data, ChannelId, 0, Data}} ->
+	    %% ssh_connection:adjust_window(ConnectionRef, ChannelId, size(Data)),
+	    %% window was pre-adjusted, don't adjust again here
+	    big_cat_rx(ConnectionRef, ChannelId, [Data | Acc]);
+	{ssh_cm, ConnectionRef, {eof, ChannelId}} ->
+	    {ok, iolist_to_binary(lists:reverse(Acc))}
+    after ?EXEC_TIMEOUT ->
+	    timeout
+    end.
+
+%%--------------------------------------------------------------------
+send_after_exit(doc) ->
+    ["Send channel data after the channel has been closed."];
+
+send_after_exit(Config) when is_list(Config) ->
+    ConnectionRef = ssh_test_lib:connect(?SSH_DEFAULT_PORT, [{silently_accept_hosts, true},
+							     {user_interaction, false}]),
+    {ok, ChannelId0} = ssh_connection:session_channel(ConnectionRef, infinity),
+
+    %% Shell command "false" will exit immediately
+    success = ssh_connection:exec(ConnectionRef, ChannelId0,
+				  "false", infinity),
+
+    timer:sleep(2000), %% Allow incoming eof/close/exit_status ssh messages to be processed
+
+    Data = <<"I like spaghetti squash">>,
+    case ssh_connection:send(ConnectionRef, ChannelId0, Data, 2000) of
+	{error, closed} -> ok;
+	ok ->
+	    ct:fail({expected,{error,closed}});
+	{error, timeout} ->
+	    ct:fail({expected,{error,closed}});
+	Else ->
+	    ct:fail(Else)
+    end,
+
+    %% receive close messages
+    receive
+	{ssh_cm, ConnectionRef, {eof, ChannelId0}} ->
+	    ok
+    end,
+    receive
+	{ssh_cm, ConnectionRef, {exit_status, ChannelId0, _}} ->
+	    ok
+    end,
+    receive
+	{ssh_cm, ConnectionRef,{closed, ChannelId0}} ->
+	    ok
+    end.
+%%--------------------------------------------------------------------
+interrupted_send(doc) ->
+    ["Use a subsystem that echos n char and then sends eof to cause a channel exit partway through a large send."];
+
+interrupted_send(Config) when is_list(Config) ->
+    PrivDir = ?config(priv_dir, Config),
+    UserDir = filename:join(PrivDir, nopubkey), % to make sure we don't use public-key-auth
+    file:make_dir(UserDir),
+    SysDir = ?config(data_dir, Config),
+    {Pid, Host, Port} = ssh_test_lib:daemon([{system_dir, SysDir},
+					     {user_dir, UserDir},
+					     {password, "morot"},
+					     {subsystems, [{"echo_n", {ssh_echo_server, [4000000]}}]}]),
+
+    ConnectionRef = ssh_test_lib:connect(Host, Port, [{silently_accept_hosts, true},
+					  {user, "foo"},
+					  {password, "morot"},
+					  {user_interaction, false},
+					  {user_dir, UserDir}]),
+
+    {ok, ChannelId} = ssh_connection:session_channel(ConnectionRef, infinity),
+
+    success = ssh_connection:subsystem(ConnectionRef, ChannelId, "echo_n", infinity),
+
+    %% build 10MB binary
+    Data = << <<X:32>> || X <- lists:seq(1,2500000)>>,
+
+    %% expect remote end to send us 4MB back
+    <<ExpectedData:4000000/binary, _/binary>> = Data,
+
+    %% pre-adjust receive window so the other end doesn't block
+    ssh_connection:adjust_window(ConnectionRef, ChannelId, size(ExpectedData) + 1),
+
+    case ssh_connection:send(ConnectionRef, ChannelId, Data, 10000) of
+	{error, closed} ->
+	    ok;
+	Msg ->
+	    ct:fail({expected,{error,closed}, got, Msg})
+    end,
+    receive_data(ExpectedData, ConnectionRef, ChannelId),
+    ssh:close(ConnectionRef),
+    ssh:stop_daemon(Pid).
+
+
+%% Internal funtions ------------------------------------------------------------------
+
+receive_data(ExpectedData, ConnectionRef, ChannelId) ->
+    ExpectedData = collect_data(ConnectionRef, ChannelId).
+
+collect_data(ConnectionRef, ChannelId) ->
+    collect_data(ConnectionRef, ChannelId, []).
+
+collect_data(ConnectionRef, ChannelId, Acc) ->
+    receive
+	{ssh_cm, ConnectionRef, {data, ChannelId, 0, Data}} ->
+	    collect_data(ConnectionRef, ChannelId, [Data | Acc]);
+	{ssh_cm, ConnectionRef, {eof, ChannelId}} ->
+	    iolist_to_binary(lists:reverse(Acc))
+    after 5000 ->
+	    timeout
+    end.
diff --git a/lib/ssh/test/ssh_connection_SUITE_data/ssh_host_rsa_key b/lib/ssh/test/ssh_connection_SUITE_data/ssh_host_rsa_key
new file mode 100644
index 0000000000..6ae7ee023d
--- /dev/null
+++ b/lib/ssh/test/ssh_connection_SUITE_data/ssh_host_rsa_key
@@ -0,0 +1,15 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----
diff --git a/lib/ssh/test/ssh_echo_server.erl b/lib/ssh/test/ssh_echo_server.erl
new file mode 100644
index 0000000000..739aabe6fb
--- /dev/null
+++ b/lib/ssh/test/ssh_echo_server.erl
@@ -0,0 +1,71 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2005-2012. 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%
+%%
+
+%%
+
+%%% Description: Example ssh server
+-module(ssh_echo_server).
+-behaviour(ssh_channel).
+-record(state, {
+	  n,
+	  id,
+	  cm
+	 }).
+-export([init/1, handle_msg/2, handle_ssh_msg/2, terminate/2]).
+
+init([N]) ->
+    {ok, #state{n = N}}.
+
+handle_msg({ssh_channel_up, ChannelId, ConnectionManager}, State) ->
+    {ok, State#state{id = ChannelId,
+		     cm = ConnectionManager}}.
+
+handle_ssh_msg({ssh_cm, CM, {data, ChannelId, 0, Data}}, #state{n = N} = State) ->
+    M = N - size(Data),
+    case M > 0 of
+	true ->
+	    ssh_connection:send(CM, ChannelId, Data),
+	    {ok, State#state{n = M}};
+	false ->
+	    <<SendData:N/binary, _/binary>> = Data,
+	    ssh_connection:send(CM, ChannelId, SendData),
+	    ssh_connection:send_eof(CM, ChannelId),
+	    {stop, ChannelId, State}
+    end;
+handle_ssh_msg({ssh_cm, _ConnectionManager,
+		{data, _ChannelId, 1, Data}}, State) ->
+    error_logger:format("ssh: STDERR: ~s\n", [binary_to_list(Data)]),
+    {ok, State};
+
+handle_ssh_msg({ssh_cm, _ConnectionManager, {eof, _ChannelId}}, State) ->
+    {ok, State};
+
+handle_ssh_msg({ssh_cm, _, {signal, _, _}}, State) ->
+    %% Ignore signals according to RFC 4254 section 6.9.
+    {ok, State};
+
+handle_ssh_msg({ssh_cm, _, {exit_signal, ChannelId, _, _Error, _}},
+	       State) ->
+    {stop, ChannelId,  State};
+
+handle_ssh_msg({ssh_cm, _, {exit_status, ChannelId, _Status}}, State) ->
+    {stop, ChannelId, State}.
+
+terminate(_Reason, _State) ->
+    ok.