"Error parsing folder listing"

[colindavidfoster]

I have never been able to successfully connect BC3 to the FTP server in one particular piece of hardware, so I've been using FileZilla which seems to be able to do so. Today I decided to investigate further and the last few lines of the section of a log file seems to be the key

15/07/2010 08:20:08 Username: SERVICE\foster_colin
15/07/2010 08:20:08 Stat> Connected.
15/07/2010 08:20:08 Recv> 220 NET+OS 7.4.1 FTP server ready.
15/07/2010 08:20:08 Sent> USER Helvar
15/07/2010 08:20:08 Recv> 331 User Helvar OK, send password.
15/07/2010 08:20:08 Sent> PASS ********
15/07/2010 08:20:08 Recv> 230 Password OK.
15/07/2010 08:20:08 Sent> FEAT
15/07/2010 08:20:08 Recv> 502 Command not implemented.
15/07/2010 08:20:08 Sent> TYPE I
15/07/2010 08:20:08 Recv> 200 Type set to I.
15/07/2010 08:20:08 Sent> SYST
15/07/2010 08:20:08 Recv> 215 NET+OS FTP for the ns9360_a
15/07/2010 08:20:08 Sent> PWD
15/07/2010 08:20:08 Recv> 257 "/FLASH0" is current directory
15/07/2010 08:20:08 Sent> REST 1
15/07/2010 08:20:08 Recv> 502 Command not implemented.
15/07/2010 08:20:08 Sent> REST 0
15/07/2010 08:20:08 Recv> 502 Command not implemented.
15/07/2010 08:20:08 Sent> TYPE A
15/07/2010 08:20:08 Recv> 200 Type set to A.
15/07/2010 08:20:08 Sent> PASV
15/07/2010 08:20:08 Recv> 227 Entering Passive Mode (10,254,1,2,195,202)
15/07/2010 08:20:08 Sent> LIST
15/07/2010 08:20:08 Recv> 150 File Listing Follows in ASCII mode
15/07/2010 08:20:09 Recv> 226 Transfer complete.
15/07/2010 08:20:09 Unable to load ftp://[email protected]/: Error parsing folder listing
15/07/2010 08:20:09 Load comparison: C:\Public\924 Touch Panel <-> ftp://[email protected]/

The FTP server in question was written by a third party, and is not particularly modern, but as pointed out above, it works fine with FileZilla and the DOS FTP command. I've used Wireshark to capture FTP accesses and the file listing returned from the device is as follows

drw-rw---- 1 noone group1 76 Jan 01 00:00 LANG\r\n
-rwlrwl--- 1 noone group1 2 Jan 01 00:00 memory.bin\r\n
drw-rw---- 1 noone group1 380 Jan 01 00:00 EMERGENCY\r\n

or in raw form including the ethernet headers

0000 00 1d 0f c0 32 ac 00 e0 aa e0 59 7d 08 00 45 00 ....2... ..Y}..E.
0010 00 de 00 02 00 00 40 06 65 18 0a fe 01 02 0a fe ......@. e.......
0020 fe 02 c3 ca c4 8a 22 b8 27 3e 31 87 05 ab 50 18 ......". '>1...P.
0030 44 70 f4 be 00 00 64 72 77 2d 72 77 2d 2d 2d 2d Dp....dr w-rw----
0040 20 31 20 6e 6f 6f 6e 65 20 20 20 20 67 72 6f 75 1 noone grou
0050 70 31 20 37 36 20 20 20 20 20 20 20 4a 61 6e 20 p1 76 Jan
0060 30 31 20 30 30 3a 30 30 20 4c 41 4e 47 0d 0a 2d 01 00:00 LANG..-
0070 72 77 6c 72 77 6c 2d 2d 2d 20 31 20 6e 6f 6f 6e rwlrwl-- - 1 noon
0080 65 20 20 20 20 67 72 6f 75 70 31 20 32 20 20 20 e gro up1 2
0090 20 20 20 20 20 4a 61 6e 20 30 31 20 30 30 3a 30 Jan 01 00:0
00a0 30 20 6d 65 6d 6f 72 79 2e 62 69 6e 0d 0a 64 72 0 memory .bin..dr
00b0 77 2d 72 77 2d 2d 2d 2d 20 31 20 6e 6f 6f 6e 65 w-rw---- 1 noone
00c0 20 20 20 20 67 72 6f 75 70 31 20 33 38 30 20 20 grou p1 380
00d0 20 20 20 20 4a 61 6e 20 30 31 20 30 30 3a 30 30 Jan 01 00:00
00e0 20 45 4d 45 52 47 45 4e 43 59 0d 0a EMERGEN CY..

[Aaron]

Hello,

Thanks for the info. If you would like, you can enable a debug directory listing by going to the Tweaks dialog (Ctrl+Shift+T), Folder Views tab, enable Include Debug messages in log.

Then email that log and a link to this forum post to [email protected]. Thanks.

[colindavidfoster]

Here's the new listing

16/07/2010 08:13:09 Username: SERVICE\foster_colin
16/07/2010 08:13:10 Stat> Connected.
16/07/2010 08:13:10 Recv> 220 NET+OS 7.4.1 FTP server ready.
16/07/2010 08:13:10 Sent> USER Helvar
16/07/2010 08:13:10 Recv> 331 User Helvar OK, send password.
16/07/2010 08:13:10 Sent> PASS ********
16/07/2010 08:13:10 Recv> 230 Password OK.
16/07/2010 08:13:10 Sent> FEAT
16/07/2010 08:13:10 Recv> 502 Command not implemented.
16/07/2010 08:13:10 Sent> TYPE I
16/07/2010 08:13:10 Recv> 200 Type set to I.
16/07/2010 08:13:10 Sent> SYST
16/07/2010 08:13:10 Recv> 215 NET+OS FTP for the ns9360_a
16/07/2010 08:13:10 Sent> PWD
16/07/2010 08:13:10 Recv> 257 "/FLASH0" is current directory
16/07/2010 08:13:10 Sent> REST 1
16/07/2010 08:13:10 Recv> 502 Command not implemented.
16/07/2010 08:13:10 Sent> REST 0
16/07/2010 08:13:10 Recv> 502 Command not implemented.
16/07/2010 08:13:10 Sent> TYPE A
16/07/2010 08:13:10 Recv> 200 Type set to A.
16/07/2010 08:13:10 Sent> PASV
16/07/2010 08:13:10 Recv> 227 Entering Passive Mode (10,254,1,2,140,160)
16/07/2010 08:13:10 Sent> LIST
16/07/2010 08:13:10 Recv> 150 File Listing Follows in ASCII mode
16/07/2010 08:13:10 Recv> 226 Transfer complete.
16/07/2010 08:13:10 drw-rw---- 1 noone group1 76 Jan 01 00:00 LANG
16/07/2010 08:13:10 -rwlrwl--- 1 noone group1 2 Jan 01 00:00 memory.bin
16/07/2010 08:13:10 drw-rw---- 1 noone group1 380 Jan 01 00:00 EMERGENCY
16/07/2010 08:13:10 FTP ParserID: Unix
16/07/2010 08:13:10 Unable to load ftp://[email protected]/: Error parsing folder listing
16/07/2010 08:13:10 Load comparison: C:\Public\924 Touch Panel <-> ftp://[email protected]/

[Zoë]

This will be easy to fix, but for our reference, what do the l's in the permissions for memory.bin mean?

[Aaron]

Thanks for the log. A developer is looking into this and we should have a fix in an upcoming version. Let us know if it works for you in the next release of BC3 (3.2 non-beta).

[colindavidfoster]

At first I thought it meant a link but that would be in the first position (Wikipedia seems to confirm this http://en.wikipedia.org/wiki/Filesys...ix_permissions). Also a link would not make sense for memory.bin since it is just a normal file, even if it is empty.

The operating system concerned is a third party affair and we have source code for some of it, including the FTP listing code. I've just looked and according to that code the file is "locked". Without looking at the FTP RFC I am guessing that the format of the FTP LIST command is well defined and the third party OS providing firm are bending/breaking the rules by putting an "l" in that postition.

[Zoë]

Actually, the FTP spec leaves the listing format completely undefined. We have about 30 distinctly different parsers, and the Unix one is extremely complicated to try to handle different date formats and missing columns.

In any case, thank you for the info. I've updated our parser, so this will be fixed in an upcoming release.