FileZilla Client (Win X64) + vsftpd server + FTPES

[Janos Kovari]

Connecting from Filezilla client, (tested: running on Vista Business x64 or XP Professional x86) to a vsftpd server (running on Ubuntu 7.04 x86 and Ubuntu 8.04 x86 (two servers) ), using FTPES and TLS authentication. Works fine, but when the client is closed or the "disconnect" button is used, it doesn't seem to disconnect from the server properly, not closing down the SSL session:

Mon Oct 12 12:30:47 2009 [pid 17113] [ftpusername] OK LOGIN: Client "11.22.33.44"
Mon Oct 12 12:31:11 2009 [pid 17114] [ftpusername] DEBUG: Client "11.22.33.44", "Connection terminated without SSL shutdown - buggy client?"

I get this on both servers, with all kinds of FZ-Windows clients. Other clients I tested seem to disconnect correctly.

[Tim Kosse]

This is harmless. Due to the nature of FTP there can be no outstanding data on the control connection when the connection gets closed, thus an SSL shutdown is not needed and in fact would only waste bandwidth.

[Janos Kovari]

Replying to codesquid:

This is harmless. Due to the nature of FTP there can be no outstanding data on the control connection when the connection gets closed, thus an SSL shutdown is not needed and in fact would only waste bandwidth.

I know it's "harmless", but still: filezilla is not closing the connection properly, while other clients do so. I'd prefer this be fixed, coz I don't wanna see this warning message flooding my logs :D (and no, i won't turn down log levels just because of this.)
I don't think sending a few more commands and packets to close down this properly is too much of a waste of bandwidth...

[Tim Kosse]

To quote RFC 959:
"An unexpected close on the control connection will cause the server to take the effective action of an abort (ABOR) and a logout (QUIT)"