SFTP Timeout/Disconnect not disconnecting filezilla

[David Bennett]

Im having an issue with Timeout's in SFTP (and have been since 3.0)

Basicly if the server connection expires/timeout's filezilla dosent know. so if i ls it works, then ls in over a minite it dosent.
see log:

Status: Directory listing successful
one min later...
Status: Retrieving directory listing...
Command: ls
Error: Network error: Software caused connection abort
Error: Failed to retrieve directory listing

I can get around this by going to "Server->Cancel current operation", "Server->Disconnect", "Server->Connect" then retrying my command :)

This is a bit of a hassle though, so if could be fixed in a later release that would be great!

Thanks,

Complistic.

[mirtschin]

I would like to add some information that I think is related. I am using WinXP SP3 with Filezilla client v3.2.7.1. The problem I am describing has been there for at least the v3.2.x versions.

After a sftp server times out, the next command issued by Filezilla doesn't execute. This can be, for example, ls, pwd or cd. A second attempt imediately after that forces Filezilla to relogin and then the command executes. The problem seems to be that Filezilla needs a failed command to notice that the server connection has disconnected.

I haven't tried the same thing after a ftp server timeout.

Here is a dump from my message log of Filezilla for the failed command:

Status: Disconnected from server
Error: Server unexpectedly closed network connection
Status: Retrieving directory listing...
Command: cd "/public_html"
Error: Failed to retrieve directory listing

Here is a dump from my message log of Filezilla for the subsequent successful command (URLs changed for privacy reasons):

Status: Connecting to zzz.org:1111...
Response: fzSftp started
Command: open "mirt@…" 1111
Command: Pass:
Status: Connected to zzz.org
Status: Retrieving directory listing...
Command: cd "/public_html/t"
Response: New directory is: "/public_html/t"
Command: ls
Status: Listing directory /public_html/t
Status: Directory listing successful

[notrone]

This is one of the few frustrating things about filezilla I have to deal with day to day. I usually leave connections open to my development site 24/7 via SSH and Filezilla (SFTP). Filezilla will eventually time out and disconnect without any notice, resulting in the next command hanging and forcing an abort and reconnect. My SSH sessions meanwhile will remain alive for weeks at a time without issue (or user activity).

I enabled tracing of an idle connection, which reveals re-keying may not be working as expected:

Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange with hash SHA-256
Trace: Initialised AES-256 SDCTR client->server encryption
Trace: Initialised HMAC-SHA-256 client->server MAC algorithm
Trace: Initialised AES-256 SDCTR server->client encryption
Trace: Initialised HMAC-SHA-256 server->client MAC algorithm
Trace: Initiating key re-exchange (timeout)
Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange with hash SHA-256
Trace: Initialised AES-256 SDCTR client->server encryption
Trace: Initialised HMAC-SHA-256 client->server MAC algorithm
Trace: Initialised AES-256 SDCTR server->client encryption
Trace: Initialised HMAC-SHA-256 server->client MAC algorithm
Trace: Initiating key re-exchange (timeout)
Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange with hash SHA-256
Trace: Initialised AES-256 SDCTR client->server encryption
Trace: Initialised HMAC-SHA-256 client->server MAC algorithm
Trace: Initialised AES-256 SDCTR server->client encryption
Trace: Initialised HMAC-SHA-256 server->client MAC algorithm
Trace: Initiating key re-exchange (timeout)
Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange with hash SHA-256
Trace: Initialised AES-256 SDCTR client->server encryption
Trace: Initialised HMAC-SHA-256 client->server MAC algorithm
Trace: Initialised AES-256 SDCTR server->client encryption
Trace: Initialised HMAC-SHA-256 server->client MAC algorithm
Trace: Initiating key re-exchange (timeout)
Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange with hash SHA-256
Trace: Initialised AES-256 SDCTR client->server encryption
Trace: Initialised HMAC-SHA-256 client->server MAC algorithm
Trace: Initialised AES-256 SDCTR server->client encryption
Trace: Initialised HMAC-SHA-256 server->client MAC algorithm
Trace: Initiating key re-exchange (timeout)
Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange with hash SHA-256

(Notice no 'Initialised encryption')?

Trace: Initiating key re-exchange (timeout)
Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange with hash SHA-256
Trace: Initialised AES-256 SDCTR client->server encryption
Trace: Initialised HMAC-SHA-256 client->server MAC algorithm
Trace: Initialised AES-256 SDCTR server->client encryption
Trace: Initialised HMAC-SHA-256 server->client MAC algorithm
Trace: Initiating key re-exchange (timeout)
Trace: Doing Diffie-Hellman group exchange

(Notice key exchange never completes)

(Issuing a new command)

Status: Retrieving directory listing...
Trace: CSftpControlSocket::SendNextCommand()
Trace: CSftpControlSocket::ChangeDirSend()
Command: cd "/"

(Freezes)

Trace: CSftpControlSocket::ResetOperation(74)
Trace: CControlSocket::ResetOperation(74)
Trace: CSftpControlSocket::ResetOperation(74)
Trace: CControlSocket::ResetOperation(74)
Error: Directory listing aborted by user

[dough]

Still seeing the same issues on SSH file listings and timeouts ( you have to x / close the connection and then reopen it to get a updated file listing). Running the latest version of filezilla client windows as of aug 20 2015.

it would be awesome to get this bug fixed.
tks