[erlang-bugs] ssh2_msg_channel_failure

Ingela Anderton Andin <>
Fri May 4 12:00:39 CEST 2012


Hello again!

After some more testing I found my first patch attempt was faulty but 
the following patch makes the problem
go away. Maybe that is why putty described their bug as "semi"-bug ("if 
handled correctly it will not matter").Well never mind, if  it ends up 
making our
ssh implementation better it was, at leas in some way, a good bug ;)

diff --git a/lib/ssh/src/ssh_connection.erl b/lib/ssh/src/ssh_connection.erl
index 46f0c7e..c46f799 100644
--- a/lib/ssh/src/ssh_connection.erl
+++ b/lib/ssh/src/ssh_connection.erl
@@ -720,12 +720,17 @@ handle_msg(#ssh_msg_channel_request{request_type = 
"env"},

 handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
                                    request_type = _Other,
-                                   want_reply = WantReply}, Connection,
+                                   want_reply = WantReply},  
#connection{channel_cache = Cache} = Connection,
           ConnectionPid, _) ->
     if WantReply == true ->
-           FailMsg = channel_failure_msg(ChannelId),
-           {{replies, [{connection_reply, ConnectionPid, FailMsg}]},
-            Connection};
+               case ssh_channel:cache_lookup(Cache, ChannelId) of
+                   #channel{remote_id = RemoteId}  ->
+                       FailMsg = channel_failure_msg(RemoteId),
+                       {{replies, [{connection_reply, ConnectionPid, 
FailMsg}]},
+                        Connection};
+                   undefined -> %% Chanel has been closed
+                       {noreply, Connection}
+               end;
        true ->
            {noreply, Connection}
     end;
diff --git a/lib/ssh/src/ssh_connection_manager.erl 
b/lib/ssh/src/ssh_connection_manager.erl
index 8c1f88e..a0ea04a 100644
--- a/lib/ssh/src/ssh_connection_manager.erl
+++ b/lib/ssh/src/ssh_connection_manager.erl
@@ -267,7 +267,7 @@ handle_call({ssh_msg, Pid, Msg}, From,
            disconnect_fun(Reason, SSHOpts),
            {stop, {shutdown, normal}, State#state{connection_state = 
Connection}}
        catch
-           _:Reason ->
+           _:Error ->
                {disconnect, Reason, {{replies, Replies}, Connection}} =
                    ssh_connection:handle_msg(
                      #ssh_msg_disconnect{code = 
?SSH_DISCONNECT_BY_APPLICATION,
@@ -277,7 +277,7 @@ handle_call({ssh_msg, Pid, Msg}, From,
                lists:foreach(fun send_msg/1, Replies),
                SSHOpts = proplists:get_value(ssh_opts, Opts),
                disconnect_fun(Reason, SSHOpts),
-               {stop, {shutdown, Reason}, State#state{connection_state 
= Connection}}
+               {stop, {shutdown, Error}, State#state{connection_state = 
Connection}}
        end;



Regards Ingela Erlang/OTP team Ericsson AB



Ingela Anderton Andin wrote:
> Hello again!
>
> I tested this some more and found that adding a sleep in 
> start_local_sshd would let the session be up longer before it crashed.
> I also traced the erlang code and I recive this message
>
> 6> (<0.61.0>) call 
> ssh_connection:handle_msg({ssh_msg_channel_request,0,"",true,<<>>},{connection,[],20497,[],1, 
>
>            {ssh_cli,[#Fun<foo.0.70052927>]},
>            "dain",2222,
>            [{role,server},
>             {pwdfun,#Fun<foo.pwdcheck.2>},
>             {system_dir,"."},
>             {shell,#Fun<foo.0.70052927>}],
>            undefined,<0.58.0>,undefined},<0.62.0>,server)
>
> which seems to be related to this putty bug:  
> http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/winadj-success.html 
>
>
> So maybe we can do something to make erlang server more graceful, but 
> it looks like the root of the problem is putty.
>
> Regards Ingela Erlang/OTP team - Ericsson AB
>
>
> Fyodor Ustinov wrote:
>> On 27.04.2012 11:54, Ingela Anderton Andin wrote:
>>> Hi!
>>>
>>> Fyodor Ustinov wrote:
>>>> Hi!
>>>>
>>>> putty say "Server send disconnect message type 11 (by application): 
>>>> "Internal error"
>>>>
>>>> Erlang say:
>>>>
>>> Interesting! It seems like the server is trying to handle a request 
>>> for a channel that has for some reason been closed.
>>> If i modify the patch like this ...
>>>
>>> diff --git a/lib/ssh/src/ssh_connection.erl 
>>> b/lib/ssh/src/ssh_connection.erl
>>> index 8574e08..fbd4967 100644
>>> --- a/lib/ssh/src/ssh_connection.erl
>>> +++ b/lib/ssh/src/ssh_connection.erl
>>> @@ -723,11 +723,14 @@ 
>>> handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
>>>                                    want_reply = WantReply},  
>>> #connection{channel_cache = Cache} = Connection,
>>>           ConnectionPid, _) ->
>>>     if WantReply == true ->
>>> -           #channel{remote_id = RemoteId} = ChannelId =
>>> -               ssh_channel:cache_lookup(Cache, ChannelId),
>>> -           FailMsg = channel_failure_msg(RemoteId),
>>> -           {{replies, [{connection_reply, ConnectionPid, FailMsg}]},
>>> -            Connection};
>>> +               case ssh_channel:cache_lookup(Cache, ChannelId) of
>>> +                   #channel{remote_id = RemoteId} = ChannelId ->
>>> +                       FailMsg = channel_failure_msg(RemoteId),
>>> +                       {{replies, [{connection_reply, 
>>> ConnectionPid, FailMsg}]},
>>> +                        Connection};
>>> +                   undefined -> %% Chanel has been closed
>>> +                       {noreply, Connection}
>>> +               end;
>>>        true ->
>>>            {noreply, Connection}
>>>     end;
>>>
>>> ... you should not get the below crash. But I am wondering if your 
>>> application will
>>> now behave as you expect?  Can you give me any more information on 
>>> the senario
>>> of your application. It would like to be able to write a minimal 
>>> test case that provokes
>>> the problem.
>> Hmm. I'll wait for the final patch. :)
>>
>> minimal test case is very simple:
>> %%%-------------------------------------------------------------------
>>
>> -module(sshd).
>> -export([start/0]).
>>
>> -export([start_local_sshd/2, pwdcheck/2]).
>>
>>
>> start() ->
>>     crypto:start(),
>>     ssh:start(),
>>     ssh:daemon(
>>         {172,28,3,22},
>>         2222,
>>         [{shell, fun (U,A) -> spawn(?MODULE, start_local_sshd, [U, 
>> A]) end},
>>         {pwdfun, fun sshd:pwdcheck/2}
>>         ]
>>     )
>> .
>>
>> pwdcheck(_Usr, _Pwd) ->
>>     true
>> .
>>
>> start_local_sshd(U, Address) ->
>>     
>> io:format("------------------------------------------------------------------------------------------------------------------------------------------------ 
>>
>> ----~n"),
>>     start_local_sshd(U, Address)
>> .
>>>
>>>
>>>> =ERROR REPORT==== 25-Apr-2012::20:03:09 ===
>>>> ** Generic server <0.156.0> terminating
>>>> ** Last message in was {ssh_msg,<0.157.0>,
>>>> <<98,0,0,0,0,0,0,0,34,119,105,110,97,100,106,
>>>>                                   
>>>> 64,112,117,116,116,121,46,112,114,111,106,
>>>>                                   
>>>> 101,99,116,115,46,116,97,114,116,97,114,117,
>>>>                                   115,46,111,114,103,1>>}
>>>> ** When Server state == {state,server,undefined,undefined,<0.157.0>,
>>>>                             {connection,[],315439,[],1,
>>>>                                 {ssh_cli,[#Fun<sshd.0.34972026>]},
>>>>                                 {10,128,0,10},
>>>>                                 2222,
>>>>                                 [{role,server},
>>>>                                  {pwdfun,#Fun<sshd.pwcheck.2>},
>>>>                                  {shell,#Fun<sshd.0.34972026>}],
>>>>                                 undefined,<0.153.0>,undefined},
>>>>                             0,
>>>>                             [{address,{10,128,0,10}},
>>>>                              {port,2222},
>>>>                              {role,server},
>>>>                              {socket_opts,[inet,{ip,{10,128,0,10}}]},
>>>>                              {ssh_opts,
>>>>                                  [{role,server},
>>>>                                   {pwdfun,#Fun<sshd.pwcheck.2>},
>>>>                                   {shell,#Fun<sshd.0.34972026>}]}],
>>>>                             undefined,true}
>>>> ** Reason for termination ==
>>>> ** {{badmatch,
>>>>         {disconnect,
>>>>             {11,"Internal error"},
>>>>             {{replies,[{channel_data,<0.159.0>,{closed,0}}]},
>>>>              {connection,[],315439,[],1,
>>>>                  {ssh_cli,[#Fun<sshd.0.34972026>]},
>>>>                  {10,128,0,10},
>>>>                  2222,
>>>>                  [{role,server},
>>>>                   {pwdfun,#Fun<sshd.pwcheck.2>},
>>>>                   {shell,#Fun<sshd.0.34972026>}],
>>>>                  undefined,<0.153.0>,undefined}}}},
>>>>     [{ssh_connection_manager,handle_call,3,
>>>>          [{file,"../src/ssh_connection_manager.erl"},{line,271}]},
>>>>      {gen_server,handle_msg,5,[{file,"gen_server.erl"},{line,588}]},
>>>>      {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,227}]}]}
>>>>
>>>> =ERROR REPORT==== 25-Apr-2012::20:03:09 ===
>>>> Erlang ssh connection handler failed with reason: {{{badmatch,
>>>>                                                      {disconnect,
>>>>                                                       {11,"Internal 
>>>> error"},
>>>>                                                       {{replies,
>>>>                                                         
>>>> [{channel_data,
>>>> <0.159.0>,
>>>>                                                           
>>>> {closed,0}}]},
>>>>                                                        
>>>> {connection,[],315439,
>>>>                                                         [],1,
>>>>                                                         {ssh_cli,
>>>>                                                          
>>>> [#Fun<sshd.0.34972026>]},
>>>>                                                         {10,128,0,10},
>>>>                                                         2222,
>>>>                                                         
>>>> [{role,server},
>>>>                                                          {pwdfun,
>>>>                                                           
>>>> #Fun<sshd.pwcheck.2>},
>>>>                                                          {shell,
>>>>                                                           
>>>> #Fun<sshd.0.34972026>}],
>>>>                                                         
>>>> undefined,<0.153.0>,
>>>>                                                         undefined}}}},
>>>>                                                     
>>>> [{ssh_connection_manager,
>>>>                                                       handle_call,3,
>>>>                                                       [{file,
>>>>                                                         
>>>> "../src/ssh_connection_manager.erl"},
>>>>                                                        {line,271}]},
>>>>                                                      
>>>> {gen_server,handle_msg,
>>>>                                                       5,
>>>>                                                       
>>>> [{file,"gen_server.erl"},
>>>>                                                        {line,588}]},
>>>>                                                      {proc_lib,
>>>>                                                       
>>>> init_p_do_apply,3,
>>>>                                                       
>>>> [{file,"proc_lib.erl"},
>>>>                                                        {line,227}]}]},
>>>>                                                    {gen_server,call,
>>>>                                                     [<0.156.0>,
>>>>                                                      
>>>> {ssh_msg,<0.157.0>,
>>>> <<93,0,0,0,0,0,0,32,106>>},
>>>>                                                      infinity]}}
>>>> , Stacktace: 
>>>> [{gen_server,call,3,[{file,"gen_server.erl"},{line,188}]},
>>>>               {ssh_connection_manager,call,3,
>>>>                   
>>>> [{file,"../src/ssh_connection_manager.erl"},{line,583}]},
>>>>               {ssh_connection_handler,generate_event,4,
>>>>                   [{file,"ssh_connection_handler.erl"},{line,804}]},
>>>>               
>>>> {gen_fsm,handle_msg,7,[{file,"gen_fsm.erl"},{line,494}]},
>>>>               
>>>> {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,227}]}]
>>>> please report this to 
>>>> =ERROR REPORT==== 25-Apr-2012::20:03:09 ===
>>>> ** State machine <0.157.0> terminating
>>>> ** Last message in was {tcp,#Port<0.1845>,<<>>}
>>>> ** When State == connected
>>>> **      Data  == {state,tcp,gen_tcp,tcp_closed,
>>>>                      {ssh,server,
>>>>                          {undefined,{{10,128,0,1},1076}},
>>>>                          {2,0},
>>>>                          {2,0},
>>>>                          
>>>> "SSH-2.0-PuTTY_Release_0.62","SSH-2.0-Erlang",
>>>> <<20,231,36,36,12,195,57,51,47,209,229,164,97,204,116,
>>>>                            
>>>> 116,90,0,0,0,154,100,105,102,102,105,101,45,104,101,
>>>>                            
>>>> 108,108,109,97,110,45,103,114,111,117,112,45,101,
>>>>                            
>>>> 120,99,104,97,110,103,101,45,115,104,97,50,53,54,44,
>>>>                            
>>>> 100,105,102,102,105,101,45,104,101,108,108,109,97,
>>>>                            
>>>> 110,45,103,114,111,117,112,45,101,120,99,104,97,110,
>>>>                            
>>>> 103,101,45,115,104,97,49,44,100,105,102,102,105,101,
>>>>                            
>>>> 45,104,101,108,108,109,97,110,45,103,114,111,117,
>>>>                            
>>>> 112,49,52,45,115,104,97,49,44,100,105,102,102,105,
>>>>                            
>>>> 101,45,104,101,108,108,109,97,110,45,103,114,111,
>>>>                            
>>>> 117,112,49,45,115,104,97,49,44,114,115,97,50,48,52,
>>>>                            
>>>> 56,45,115,104,97,50,53,54,44,114,115,97,49,48,50,52,
>>>>                            
>>>> 45,115,104,97,49,0,0,0,15,115,115,104,45,114,115,97,
>>>>                            
>>>> 44,115,115,104,45,100,115,115,0,0,0,159,97,101,115,
>>>>                            
>>>> 50,53,54,45,99,116,114,44,97,101,115,50,53,54,45,99,
>>>>                            
>>>> 98,99,44,114,105,106,110,100,97,101,108,45,99,98,99,
>>>>                            
>>>> 64,108,121,115,97,116,111,114,46,108,105,117,46,115,
>>>>                            
>>>> 101,44,97,101,115,49,57,50,45,99,116,114,44,97,101,
>>>>                            
>>>> 115,49,57,50,45,99,98,99,44,97,101,115,49,50,56,45,
>>>>                            
>>>> 99,116,114,44,97,101,115,49,50,56,45,99,98,99,44,98,
>>>>                            
>>>> 108,111,119,102,105,115,104,45,99,116,114,44,98,108,
>>>>                            
>>>> 111,119,102,105,115,104,45,99,98,99,44,51,100,101,
>>>>                            
>>>> 115,45,99,116,114,44,51,100,101,115,45,99,98,99,44,
>>>>                            
>>>> 97,114,99,102,111,117,114,50,53,54,44,97,114,99,102,
>>>>                            
>>>> 111,117,114,49,50,56,0,0,0,159,97,101,115,50,53,54,
>>>>                            
>>>> 45,99,116,114,44,97,101,115,50,53,54,45,99,98,99,44,
>>>>                            
>>>> 114,105,106,110,100,97,101,108,45,99,98,99,64,108,
>>>>                            
>>>> 121,115,97,116,111,114,46,108,105,117,46,115,101,44,
>>>>                            
>>>> 97,101,115,49,57,50,45,99,116,114,44,97,101,115,49,
>>>>                            
>>>> 57,50,45,99,98,99,44,97,101,115,49,50,56,45,99,116,
>>>>                            
>>>> 114,44,97,101,115,49,50,56,45,99,98,99,44,98,108,
>>>>                            
>>>> 111,119,102,105,115,104,45,99,116,114,44,98,108,111,
>>>>                            
>>>> 119,102,105,115,104,45,99,98,99,44,51,100,101,115,
>>>>                            
>>>> 45,99,116,114,44,51,100,101,115,45,99,98,99,44,97,
>>>>                            
>>>> 114,99,102,111,117,114,50,53,54,44,97,114,99,102,
>>>>                            
>>>> 111,117,114,49,50,56,0,0,0,31,104,109,97,99,45,115,
>>>>                            
>>>> 104,97,49,44,104,109,97,99,45,115,104,97,49,45,57,
>>>>                            
>>>> 54,44,104,109,97,99,45,109,100,53,0,0,0,31,104,109,
>>>>                            
>>>> 97,99,45,115,104,97,49,44,104,109,97,99,45,115,104,
>>>>                            
>>>> 97,49,45,57,54,44,104,109,97,99,45,109,100,53,0,0,0,
>>>>                            
>>>> 9,110,111,110,101,44,122,108,105,98,0,0,0,9,110,111,
>>>>                            
>>>> 110,101,44,122,108,105,98,0,0,0,0,0,0,0,0,0,0,0,0,0>>,
>>>> <<20,68,106,202,126,189,248,249,152,175,237,102,43,
>>>>                            
>>>> 239,21,11,93,0,0,0,26,100,105,102,102,105,101,45,
>>>>                            
>>>> 104,101,108,108,109,97,110,45,103,114,111,117,112,
>>>>                            
>>>> 49,45,115,104,97,49,0,0,0,15,115,115,104,45,114,115,
>>>>                            
>>>> 97,44,115,115,104,45,100,115,115,0,0,0,19,97,101,
>>>>                            
>>>> 115,49,50,56,45,99,98,99,44,51,100,101,115,45,99,98,
>>>>                            
>>>> 99,0,0,0,19,97,101,115,49,50,56,45,99,98,99,44,51,
>>>>                            
>>>> 100,101,115,45,99,98,99,0,0,0,9,104,109,97,99,45,
>>>>                            
>>>> 115,104,97,49,0,0,0,9,104,109,97,99,45,115,104,97,
>>>>                            
>>>> 49,0,0,0,9,110,111,110,101,44,122,108,105,98,0,0,0,
>>>>                            
>>>> 9,110,111,110,101,44,122,108,105,98,0,0,0,0,0,0,0,0,
>>>>                            0,0,0,0,0>>,
>>>>                          
>>>> undefined,'diffie-hellman-group1-sha1','ssh-rsa',
>>>>                          ssh_file,ssh_io,'hmac-sha1',
>>>> <<92,89,171,169,113,136,6,188,156,238,58,144,38,214,
>>>>                            101,198,247,166,205,208>>,
>>>>                          20,'hmac-sha1',
>>>> <<24,206,173,99,5,252,206,70,166,228,30,17,101,89,36,
>>>>                            241,175,116,238,86>>,
>>>>                          20,'aes128-cbc',
>>>> <<45,208,196,236,205,82,244,222,24,132,67,151,22,62,
>>>>                            250,150>>,
>>>>                          16,
>>>> <<219,113,112,85,250,220,170,249,194,198,230,158,76,
>>>>                            122,39,155>>,
>>>>                          'aes128-cbc',
>>>> <<44,157,215,194,90,86,202,31,228,49,188,97,227,97,
>>>>                            233,144>>,
>>>>                          16,
>>>> <<196,110,206,199,93,111,201,100,74,194,231,242,179,
>>>>                            201,15,112>>,
>>>>                          none,undefined,none,undefined,none,none,true,
>>>>                          infinity,
>>>>                          
>>>> 132151717501655075704740428602371821313660310182519774905429178494543592682738802201444120687073445805819575914576401425536104160589136387731343596760889931670361900328999551747697001054684538185039596790225261438983095509229017954492065022996307622720613396529860286665422597229362632923823896919144441708303, 
>>>>
>>>> <<163,238,219,114,10,240,95,30,207,178,78,138,146,58,
>>>>                            87,102,43,69,173,214>>,
>>>> <<163,238,219,114,10,240,95,30,207,178,78,138,146,58,
>>>>                            87,102,43,69,173,214>>,
>>>>                          [{address,{10,128,0,10}},
>>>>                           {port,2222},
>>>>                           {role,server},
>>>>                           {pwdfun,#Fun<sshd.pwcheck.2>},
>>>>                           {shell,#Fun<sshd.0.34972026>}],
>>>>                          114,49,
>>>>                          
>>>> {{49985839305237737688589908016292087537304670681285167039328910635484947391794443232164854289884214947929742793900078775832939310627327467626874637085242037758449972175725827907772272533385534014381436171929411436926043326068534386929776710296045274502307637113679098707841881585433086106245829282665980090815, 
>>>>
>>>>                            
>>>> 8395950144135694221446766804944646771011612746974327140375413192360614631043395924085970461957169944119762874929925969231067866506208529309578676567265288403413833138477256106374779295193693244061192404399083583730265790053008130870886892278024924477046645863115470835406736499812828883753405586277633495326}, 
>>>>
>>>>                           {2,
>>>>                            
>>>> 179769313486231590770839156793787453197860296048756011706444423684197180216158519368947833795864925541502180565485980503646440548199239100050792877003355816639229553136239076508735759914822574862575007425302077447712589550957937778424442426617334727629299387668709205606050270810842907692932019128194467627007}}, 
>>>>
>>>>                          
>>>> undefined,undefined,"ssh-connection",undefined,
>>>>                          
>>>> "publickey,keyboard_interactive,password",undefined,
>>>>                          undefined,
>>>>                          ["ssh-rsa","ssh-dss"]},
>>>>                      #Port<0.1845>,<<>>,
>>>> <<107,0,185,229,147,59,116,109,92,16,81,210,0,243,152,220,
>>>>                        
>>>> 153,112,133,2,156,113,5,213,202,236,150,200,184,190,61,
>>>>                        
>>>> 227,37,31,157,1,53,98,136,245,199,18,165,166,214,36,210,
>>>>                        12,92,130,17,174>>,
>>>>                      undefined,
>>>>                      {ssh_msg_kexinit,
>>>> <<126,96,184,235,216,208,69,175,215,35,94,180,214,20,
>>>>                            246,141>>,
>>>>                          ["diffie-hellman-group1-sha1"],
>>>>                          ["ssh-rsa","ssh-dss"],
>>>>                          ["aes128-cbc","3des-cbc"],
>>>>                          ["aes128-cbc","3des-cbc"],
>>>>                          ["hmac-sha1"],
>>>>                          ["hmac-sha1"],
>>>>                          ["none","zlib"],
>>>>                          ["none","zlib"],
>>>>                          [],[],false,0},
>>>>                      false,<0.156.0>,undefined,undefined,undefined,
>>>>                      [{address,{10,128,0,10}},
>>>>                       {port,2222},
>>>>                       {role,server},
>>>>                       {pwdfun,#Fun<sshd.pwcheck.2>},
>>>>                       {shell,#Fun<sshd.0.34972026>}]}
>>>> ** Reason for termination =
>>>> ** {{{badmatch,
>>>>          {disconnect,
>>>>              {11,"Internal error"},
>>>>              {{replies,[{channel_data,<0.159.0>,{closed,0}}]},
>>>>               {connection,[],315439,[],1,
>>>>                   {ssh_cli,[#Fun<sshd.0.34972026>]},
>>>>                   {10,128,0,10},
>>>>                   2222,
>>>>                   [{role,server},
>>>>                    {pwdfun,#Fun<sshd.pwcheck.2>},
>>>>                    {shell,#Fun<sshd.0.34972026>}],
>>>>                   undefined,<0.153.0>,undefined}}}},
>>>>      [{ssh_connection_manager,handle_call,3,
>>>>           [{file,"../src/ssh_connection_manager.erl"},{line,271}]},
>>>>       {gen_server,handle_msg,5,[{file,"gen_server.erl"},{line,588}]},
>>>>       
>>>> {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,227}]}]},
>>>>     {gen_server,call,
>>>>         
>>>> [<0.156.0>,{ssh_msg,<0.157.0>,<<93,0,0,0,0,0,0,32,106>>},infinity]}}
>>>>
>>>>
>>>>
>>>>> Hi!
>>>>>
>>>>> Daniel Goertzen wrote:
>>>>>> The channel number on the putty side is 0x100, and on the Erlang 
>>>>>> side it is 0x0.  Erlang is responding to SSH_MSG_CHANNEL_REQUEST 
>>>>>> using 0x0, however RFC4254 says the responses should be...
>>>>>>
>>>>>>
>>>>>>       byte      SSH_MSG_CHANNEL_SUCCESS
>>>>>>       uint32    recipient channel
>>>>>>
>>>>>>
>>>>>>       byte      SSH_MSG_CHANNEL_FAILURE
>>>>>>       uint32    recipient channel
>>>>>>
>>>>>>
>>>>>> ...and I interpret "recipient channel" as being the Putty side, 
>>>>>> which is 0x100.  Putty seems to cope when Erlang returns SUCCESS, 
>>>>>> but blows up when Erlang returns a FAILURE.
>>>>>>
>>>>>
>>>>> Yes that is correct I remember correcting such a bug a long time 
>>>>> ago, checking the code however there seems to be one error 
>>>>> handling case that I missed.  Could you check if
>>>>> the following patch resolves your issue Fyodor?
>>>>>
>>>>> diff --git a/lib/ssh/src/ssh_connection.erl 
>>>>> b/lib/ssh/src/ssh_connection.erl
>>>>> index 46f0c7e..8574e08 100644
>>>>> --- a/lib/ssh/src/ssh_connection.erl
>>>>> +++ b/lib/ssh/src/ssh_connection.erl
>>>>> @@ -720,10 +720,12 @@ 
>>>>> handle_msg(#ssh_msg_channel_request{request_type = "env"},
>>>>>
>>>>> handle_msg(#ssh_msg_channel_request{recipient_channel = ChannelId,
>>>>>                                    request_type = _Other,
>>>>> -                                   want_reply = WantReply}, 
>>>>> Connection,
>>>>> +                                   want_reply = WantReply},  
>>>>> #connection{channel_cache = Cache} = Connection,
>>>>>           ConnectionPid, _) ->
>>>>>     if WantReply == true ->
>>>>> -           FailMsg = channel_failure_msg(ChannelId),
>>>>> +           #channel{remote_id = RemoteId} = ChannelId =
>>>>> +               ssh_channel:cache_lookup(Cache, ChannelId),
>>>>> +           FailMsg = channel_failure_msg(RemoteId),
>>>>>            {{replies, [{connection_reply, ConnectionPid, FailMsg}]},
>>>>>             Connection};
>>>>>        true ->
>>>>>
>>>>>
>>>>>> I could imagine this passing automated tests when both ends 
>>>>>> number their channels starting from 0.  I bet randomizing the 
>>>>>> channel numbers would reveal this and maybe other issues.
>>>>>>
>>>>>> Dan.
>>>>>>
>>>>> I think you have a valid point however we have to change the 
>>>>> implementation in one way or an other to do that and that has not 
>>>>> been prioritized.
>>>>>
>>>>>
>>>>> Regards Ingela Erlang/OTP team -Ericsson AB
>>>>>
>>>>>>
>>>>>> On Tue, Apr 24, 2012 at 11:22 AM, Fyodor Ustinov < 
>>>>>> <mailto:>> wrote:
>>>>>>
>>>>>>     Hi!
>>>>>>
>>>>>>     I added this patch - did not help.
>>>>>>
>>>>>>     http://blog.ufm.su/putty.log - this putty log.
>>>>>>
>>>>>>
>>>>>>         Hi!
>>>>>>
>>>>>>         This might be a symptom of the "close race-condition"-bug
>>>>>>          reported by Daniel. The patch for that bug is
>>>>>>
>>>>>>         diff --git a/lib/ssh/src/ssh_channel.erl
>>>>>>         b/lib/ssh/src/ssh_channel.erl
>>>>>>         index 7b600ed..1938858 100644
>>>>>>         --- a/lib/ssh/src/ssh_channel.erl
>>>>>>         +++ b/lib/ssh/src/ssh_channel.erl
>>>>>>         @@ -1,7 +1,7 @@
>>>>>>         %%
>>>>>>         %% %CopyrightBegin%
>>>>>>         %%
>>>>>>         -%% Copyright Ericsson AB 2008-2011. All Rights Reserved.
>>>>>>         +%% 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
>>>>>>         @@ -215,7 +215,7 @@ handle_info({ssh_cm, ConnectionManager,
>>>>>>         {closed, ChannelId}},
>>>>>>                          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};
>>>>>>         +    {stop, normal, State#state{close_sent = true}};
>>>>>>
>>>>>>         handle_info({ssh_cm, _, _} = Msg, #state{cm = 
>>>>>> ConnectionManager,
>>>>>>                               channel_cb = Module,
>>>>>>         diff --git a/lib/ssh/src/ssh_connection_manager.erl
>>>>>>         b/lib/ssh/src/ssh_connection_manager.erl
>>>>>>         index e993f59..8c1f88e 100644
>>>>>>         --- a/lib/ssh/src/ssh_connection_manager.erl
>>>>>>         +++ b/lib/ssh/src/ssh_connection_manager.erl
>>>>>>         @@ -384,9 +384,10 @@ handle_call({close, ChannelId}, _,
>>>>>>                   #state{connection = Pid, connection_state =
>>>>>>                          #connection{channel_cache = Cache}} = 
>>>>>> State) ->
>>>>>>            case ssh_channel:cache_lookup(Cache, ChannelId) of
>>>>>>         -       #channel{remote_id = Id} ->
>>>>>>         +       #channel{remote_id = Id} = Channel ->
>>>>>>                   send_msg({connection_reply, Pid,
>>>>>>                             ssh_connection:channel_close_msg(Id)}),
>>>>>>         +           ssh_channel:cache_update(Cache,
>>>>>>         Channel#channel{sent_close = true}),
>>>>>>                   {reply, ok, State};
>>>>>>               undefined ->
>>>>>>                   {reply, ok, State}
>>>>>>
>>>>>>
>>>>>>         Regards Ingela Erlang/OTP  team - Ericsson AB
>>>>>>
>>>>>>         Daniel Goertzen wrote:
>>>>>>
>>>>>>             Under Putty Session->Logging can you turn on "SSH 
>>>>>> Packets"
>>>>>>             and post the log showing the error?
>>>>>>
>>>>>>             Dan.
>>>>>>
>>>>>>             On Sun, Apr 22, 2012 at 3:58 AM, Fyodor Ustinov
>>>>>> < <mailto:> <mailto:
>>>>>> <mailto:>>> wrote:
>>>>>>
>>>>>>                Hi!
>>>>>>
>>>>>>                Windows ssh client PuTTY show message  "Disconnected:
>>>>>>             Received
>>>>>>                SSH2_MSG_CHANNEL_FAILURE for nonexistent channel 0"
>>>>>>             while working
>>>>>>                with erlang ssh daemon.
>>>>>>
>>>>>>                Erlang R15B01 (erts-5.9.1) [source] [64-bit] 
>>>>>> [smp:8:8]
>>>>>>                [async-threads:0] [kernel-poll:false]
>>>>>>
>>>>>>                WBR,
>>>>>>                   Fyodor.
>>>>>>
>>>>>>                _______________________________________________
>>>>>>                erlang-bugs mailing list
>>>>>>                 
>>>>>> <mailto:>
>>>>>> <mailto:
>>>>>> <mailto:>>
>>>>>>                http://erlang.org/mailman/listinfo/erlang-bugs
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>             --             *Daniel Goertzen | Senior Software 
>>>>>> Engineer*
>>>>>>             Office: 828.610.4596 <tel:828.610.4596> | Fax:
>>>>>>             828.322.5294 <tel:828.322.5294> |
>>>>>>             
>>>>>> <mailto:>
>>>>>> <mailto:
>>>>>> <mailto:>>
>>>>>>             *Network Integrity Systems | We Bring Security To 
>>>>>> Light™*
>>>>>>
>>>>>>             1937 Tate Blvd. SE
>>>>>>
>>>>>>             Hickory, North Carolina, USA 28602
>>>>>>
>>>>>>             /Network Integrity Systems’ INTERCEPTOR™ Optical Network
>>>>>>             Security System is a Smart-PDS™ that ensures superior
>>>>>>             protection and cost effectiveness of classified 
>>>>>> networks.
>>>>>>              For more information, visit our website
>>>>>>             at:www.networkintegritysystems.com
>>>>>> <http://www.networkintegritysystems.com>
>>>>>> <http://www.networkintegritysystems.com/>./
>>>>>>
>>>>>>
>>>>>>             __________________________________________
>>>>>>             INTERCEPTOR™ Optical Network Security System is made in
>>>>>>             the USA for the USA. Although not an export controlled
>>>>>>             item, because of the role it plays in the assurance 
>>>>>> of the
>>>>>>             safety and integrity of National Security Information,
>>>>>>             Network Integrity Systems (NIS) is committed to 
>>>>>> compliance
>>>>>>             with the U.S. Export Administration Act. Accordingly, 
>>>>>> NIS
>>>>>>             will not ship INTERCEPTOR products to certain foreign
>>>>>>             government end users without U.S. government approval 
>>>>>> and
>>>>>>             will refuse transactions with individuals or entities 
>>>>>> that
>>>>>>             have been denied export privileges.
>>>>>>
>>>>>>
>>>>>>             
>>>>>> ------------------------------------------------------------------------ 
>>>>>>
>>>>>>
>>>>>>             _______________________________________________
>>>>>>             erlang-bugs mailing list
>>>>>>              <mailto:>
>>>>>>             http://erlang.org/mailman/listinfo/erlang-bugs
>>>>>>
>>>>>>
>>>>>>
>>>>>>     _______________________________________________
>>>>>>     erlang-bugs mailing list
>>>>>>      <mailto:>
>>>>>>     http://erlang.org/mailman/listinfo/erlang-bugs
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> -- 
>>>>>> *Daniel Goertzen | Senior Software Engineer*
>>>>>> Office: 828.610.4596 | Fax: 828.322.5294 | 
>>>>>>  
>>>>>> <mailto:>
>>>>>> *Network Integrity Systems | We Bring Security To Light™*
>>>>>>
>>>>>> 1937 Tate Blvd. SE
>>>>>>
>>>>>> Hickory, North Carolina, USA 28602
>>>>>>
>>>>>> /Network Integrity Systems’ INTERCEPTOR™ Optical Network Security 
>>>>>> System is a Smart-PDS™ that ensures superior protection and cost 
>>>>>> effectiveness of classified networks.  For more information, 
>>>>>> visit our website at:www.networkintegritysystems.com 
>>>>>> <http://www.networkintegritysystems.com/>./
>>>>>>
>>>>>>
>>>>>> __________________________________________
>>>>>> INTERCEPTOR™ Optical Network Security System is made in the USA 
>>>>>> for the USA. Although not an export controlled item, because of 
>>>>>> the role it plays in the assurance of the safety and integrity of 
>>>>>> National Security Information, Network Integrity Systems (NIS) is 
>>>>>> committed to compliance with the U.S. Export Administration Act. 
>>>>>> Accordingly, NIS will not ship INTERCEPTOR products to certain 
>>>>>> foreign government end users without U.S. government approval and 
>>>>>> will refuse transactions with individuals or entities that have 
>>>>>> been denied export privileges.
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
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