Subj : Data connection already open?
To   : g00r00
From : Bj”rn Wiberg
Date : Mon Mar 14 2022 07:04 pm

Hello g00r00!

When using the FTP server with passive FTP (e.g. the 'pftp' command), I get a lot of "Data connection already open" messages followed by "Closing data connection". Is this normal?

(The file listings show up as they should.)

+ 2022.03.14 18:53:37  FTP > Connect on slot 1/10 (127.0.0.1)
+ 2022.03.14 18:53:37  FTP 1-HostName localhost.localdomain
+ 2022.03.14 18:53:37  FTP 1-Country  Unknown (-)
+ 2022.03.14 18:53:38  FTP 1-C: USER Data: guest
+ 2022.03.14 18:53:38  FTP 1-S: 331 User name okay, need password.
+ 2022.03.14 18:53:39  FTP 1-C: PASS
+ 2022.03.14 18:53:39  FTP 1-S: 230 User logged in, proceed.
+ 2022.03.14 18:53:39  FTP 1-Logged in as guest
+ 2022.03.14 18:53:39  FTP 1-C: SYST Data:
+ 2022.03.14 18:53:39  FTP 1-S: 215 UNIX Type: L8
+ 2022.03.14 18:53:40  FTP 1-C: PASV Data:
+ 2022.03.14 18:53:40  FTP 1-S: 227 Entering Passive Mode (188,149,138,116,198,212).
+ 2022.03.14 18:53:40  FTP 1-C: LIST Data:
+ 2022.03.14 18:53:40  FTP 1-Listing files in /
+ 2022.03.14 18:53:40  FTP 1-S: 125 Data connection already open
+ 2022.03.14 18:53:40  FTP 1-S: 226 Closing data connection.
+ 2022.03.14 18:53:43  FTP 1-C: CWD Data: uploads
+ 2022.03.14 18:53:43  FTP 1-S: 250 Working directory is now "/uploads"
+ 2022.03.14 18:53:43  FTP 1-Changed to uploads
+ 2022.03.14 18:53:44  FTP 1-C: PASV Data:
+ 2022.03.14 18:53:44  FTP 1-S: 227 Entering Passive Mode (188,149,138,116,198,212).
+ 2022.03.14 18:53:44  FTP 1-C: LIST Data:
+ 2022.03.14 18:53:44  FTP 1-Listing files in uploads
+ 2022.03.14 18:53:44  FTP 1-S: 125 Data connection already open
+ 2022.03.14 18:53:44  FTP 1-S: 226 Closing data connection.
+ 2022.03.14 18:53:52  FTP 1-C: QUIT Data:
+ 2022.03.14 18:53:52  FTP 1-S: 221 Goodbye
+ 2022.03.14 18:53:52  FTP 1-Connection closed

Active FTP (e.g. the 'ftp' command) does not exhibit this:

+ 2022.03.14 19:02:33  FTP > Connect on slot 1/10 (192.168.1.1)
+ 2022.03.14 19:02:33  FTP 1-HostName router.asus.com
+ 2022.03.14 19:02:33  FTP 1-Country  Unknown (-)
+ 2022.03.14 19:02:35  FTP 1-C: USER Data: guest
+ 2022.03.14 19:02:35  FTP 1-S: 331 User name okay, need password.
+ 2022.03.14 19:02:36  FTP 1-C: PASS
+ 2022.03.14 19:02:36  FTP 1-S: 230 User logged in, proceed.
+ 2022.03.14 19:02:36  FTP 1-Logged in as guest
+ 2022.03.14 19:02:36  FTP 1-C: SYST Data:
+ 2022.03.14 19:02:36  FTP 1-S: 215 UNIX Type: L8
+ 2022.03.14 19:02:37  FTP 1-C: PORT Data: 192,168,1,5,145,95
+ 2022.03.14 19:02:37  FTP 1-S: 200 Command okay.
+ 2022.03.14 19:02:37  FTP 1-C: LIST Data:
+ 2022.03.14 19:02:37  FTP 1-Listing files in /
+ 2022.03.14 19:02:37  FTP 1-S: 150 File status okay; opening data connection.
+ 2022.03.14 19:02:37  FTP 1-Connecting to 192.168.1.5 port 37215
+ 2022.03.14 19:02:37  FTP 1-Data connection established
+ 2022.03.14 19:02:37  FTP 1-S: 226 Closing data connection.
+ 2022.03.14 19:02:38  FTP 1-C: PORT Data: 192,168,1,5,199,253
+ 2022.03.14 19:02:38  FTP 1-S: 200 Command okay.
+ 2022.03.14 19:02:38  FTP 1-C: LIST Data:
+ 2022.03.14 19:02:38  FTP 1-Listing files in /
+ 2022.03.14 19:02:38  FTP 1-S: 150 File status okay; opening data connection.
+ 2022.03.14 19:02:38  FTP 1-Connecting to 192.168.1.5 port 51197
+ 2022.03.14 19:02:38  FTP 1-Data connection established
+ 2022.03.14 19:02:38  FTP 1-S: 226 Closing data connection.
+ 2022.03.14 19:02:39  FTP 1-C: QUIT Data:
+ 2022.03.14 19:02:39  FTP 1-S: 221 Goodbye
+ 2022.03.14 19:02:39  FTP 1-Connection closed

I have the Time Out for the FTP server set to 300 seconds, if that would matter somehow.

Thanks in advance!

Best regards
Bj”rn

--- Mystic BBS v1.12 A48 2022/03/11 (Linux/64)
 * Origin: Star Collision BBS, Uppsala, Sweden (2:201/137)

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