[SOLVED] FTP error >>> CURLE_FTP_COULDNT_RETR_FILE

[h2o2]

Cannot read directory
"ftp://192.168.1.4/Qbackup/DriveA/black seed oil".

CURLE_FTP_COULDNT_RETR_FILE: RETR response: 501
501 Invalid number of arguments [curl_easy_perform]


Hi!

FreeFileSync (v. 11.2 64-bit 02.10.2020) сan not read FTP folders with space in path.
I did first mirror without any questions.
FreeFileSync made aqurate copy on FTP server.
But later I see that FreeFileSync can not read FTP folders with spaces in path during "Compare" command.

Client:

root@azulle:/# uname -a
Linux azulle 4.19.0-12-amd64 #1 SMP Debian 4.19.152-1 (2020-10-18) x86_64 GNU/Linux


Server:

[~] # uname -a
Linux QNAP 2.6.30.6 #1 Tue Jul 20 05:17:10 CST 2010 armv5tel unknown


All others FTP clients work Ok with this server.

[Zenju]

Can you update the FTP server software? Looks like a server bug.
If not, next step would be to find out what command FFS is sending to the server and see if the format is correct, e.g. via Wireshark.

[h2o2]

Can you update the FTP server software? Looks like a server bug.

All other FTP clients work Ok with this server.

If not, next step would be to find out what command FFS is sending to the server and see if the format is correct, e.g. via Wireshark.

Ok, found.

Double Commander --- Ok

----
# Packet 2 from /tmp/wireshark_enp1s0_20201102141442_tHC18a.pcapng
- 3
- 2.425972176
- 192.168.1.2
- 192.168.1.4
- FTP
- 107
- Request: CWD /Qbackup/DriveA/Untitled Folder/


FreeFileSync --- Bug

----
# Packet 107 from /tmp/wireshark_enp1s0_20201102135938_3hPKez.pcapng
- 108
- 4.125215973
- 192.168.1.2
- 192.168.1.4
- FTP
- 107
- Request: MLSD /Qbackup/DriveA/Untitled Folder


As you can see, authors of FreeFileSync
- forgot "/" symbol at the end of request argument
- use MLSD

[Zenju]

# Packet 107 from /tmp/wireshark_enp1s0_20201102135938_3hPKez.pcapng
- Request: MLSD /Qbackup/DriveA/Untitled Folder

The MLSD syntax looks correct. What happens if you manually issue "MLSD /Qbackup/DriveA/Untitled Folder/"? E.g. you can send manual FTP commands with FileZilla.

[Zenju]

I think QNAP uses proftpd for FTP internally.

proftpd had bugs with spaces in file names before (in very old releases):

1.3.2rc4 - Released 23-Jan-2009
--------------------------------
- Bug 3142 - "Invalid number of arguments MFMT" due to spaces in path argument.

Your version of QNAP is also ancient: Tue Jul 20 05:17:10 CST 2010

Updating QNAP will most likely fix the "Invalid number of arguments" bug.

[h2o2]

FileZilla uses CWD without "/" and OK.

Custom command test:
- MLSD >>> Does not working with ending "/"
- CWD >>> The ending "/" symbol does not matter

[h2o2]

Updating QNAP will most likely fix the "Invalid number of arguments" bug.

I will think about it.

p.s. I checked other my progs.
They start from CWD.
For example, requests CWD >>> PASV >>> MLSD.

[h2o2]

Updating QNAP will most likely fix the "Invalid number of arguments" bug.

Works. Thanks.

[~] # uname -a
Linux QNAP 3.4.6 #1 Tue Oct 6 11:39:23 CST 2020 armv5tel unknown


[~] # proftpd -v 
ProFTPD Version 1.3.5a