Error messages when connecting via CyberDuck FTP Client

[Kevin Bombino]

Hi all,

I have set up an FTP server powered by pyftpdlib. Many thanks for all
your work on this. It's great. I have noticed though, when
connecting via the CyberDuck FTP Client on Mac OS X, and trying to
download a folder's contents, I get an error message.

CyberDuck pops up an error window displaying this error message:
"Data connection already open; transfer starting."

The best I can understand is that pyftpdlib is sending a "125" code,
which CyberDuck is mistakenly interpreting as an error condition in
this situation. This may be a CyberDuck bug, but I don't experience
this when I connect to other FTP servers using CyberDuck.

Here is the relevant section of the log output (note I blacked out the
IP addresses and path with Xs and Ys):

X.X.X.X:55771 <== NOOP
X.X.X.X:55771 ==> 200 I successfully done nothin'.
X.X.X.X:55771 <== CWD /X/X/X/X
[bombino]@X.X.X.X:55771 OK CWD "/X/X/X/X".
X.X.X.X:55771 ==> 250 "/X/X/X/X" is the current directory.
X.X.X.X:55771 <== STAT /X/X/X/X
X.X.X.X:55771 ==> 213 End of status.
X.X.X.X:55771 <== PASV
X.X.X.X:55771 ==> 227 Entering passive mode (Y,Y,Y,Y,189,139).
X.X.X.X:55771 <== MLSD
[bombino]@X.X.X.X:55771 OK MLSD "/X/X/X/X". Transfer starting.
X.X.X.X:55771 ==> 125 Data connection already open. Transfer starting.
X.X.X.X:55771 ==> 226 Transfer complete.
X.X.X.X:55771 <== NOOP
X.X.X.X:55771 ==> 200 I successfully done nothin'.
[bombino]@X.X.X.X:55771 Disconnected.

It looks like that 125 code is the source of CyberDuck's popup.

Does anyone have any suggestions of things I could try or how I could
provide more information that might give any of the developers some
more insight into the problem?

Thanks in advance,
Kevin Bombino

[Giampaolo Rodola']

Hi Kevin,
as stated by RFC-959 in various chapters 125 is the correct code to
send in that situation so I believe it's CyberDuck's fault.
I don't know what could you do except asking to CyberDuck's developers
if they know something about this.
By taking a look at your log it seems that the transfer goes well,
btw.