LinuxQuestions.org
Support LQ: Use code LQ3 and save $3 on Domain Registration
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Distributions > Slackware
User Name
Password
Slackware This Forum is for the discussion of Slackware Linux.

Notices

Reply
 
Search this Thread
Old 09-01-2012, 06:08 AM   #1
Martinus2u
Member
 
Registered: Apr 2010
Distribution: Slackware
Posts: 345

Rep: Reputation: 56
breaking ftp connections with vsftpd on -current


since a recent -current upgrade I've had this issue that ftp connections in my LAN would break as soon as a data connection was opened.

I am currently on RC4.

Symptoms: midnight commander refuses to enter a directory with a red popup saying
Code:
Error - cannot change directory
In the classical ftp client the problem can be triggered by using the ls command (active or passive mode irrelevant):
Code:
ftp> ls
200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
421 Service not available, remote server has closed connection
Code:
ftp> pa
Passive mode on.
ftp> ls
227 Entering Passive Mode (...).
150 Here comes the directory listing.
421 Service not available, remote server has closed connection
this happens for localhost and remote hosts, but not consistently for all directories.

I'm investigating, but maybe someone has an idea where else to look?

Update: normally started from inetd without tcp wrappers, i have tried standalone mode. result is the same.

Last edited by Martinus2u; 09-01-2012 at 06:23 AM.
 
Old 09-01-2012, 09:41 AM   #2
Martinus2u
Member
 
Registered: Apr 2010
Distribution: Slackware
Posts: 345

Original Poster
Rep: Reputation: 56
Strace reveals that the vsftpd server process is killed by a SIGSYS signal. Internet studies reveal that this signal may be related to something called "seccomp filter sandboxing" which was newly introduced in vsftpd-3.0.0.

Reverting vsftpd back to 2.3.4 (ie. the package delivered in Slackware 13.37) solves the issue.

With regards to Slackware 14, how to proceed with this?
 
Old 09-10-2012, 04:32 PM   #3
Martinus2u
Member
 
Registered: Apr 2010
Distribution: Slackware
Posts: 345

Original Poster
Rep: Reputation: 56
quick update: what I didn't know is the option
Code:
seccomp_sandbox=NO
which makes 3.0.0 work on my machine.

The other thing I found out: the issue is probably related to my kernel version (3.5.3) or config. Good news for Slackware 14.0: the issue is not present when booting the distro kernel.

Still investigating.
 
Old 09-16-2012, 06:04 AM   #4
Martinus2u
Member
 
Registered: Apr 2010
Distribution: Slackware
Posts: 345

Original Poster
Rep: Reputation: 56
update: Chris has put out version 3.0.1 which solves the issue. I had a build issue though (that can be overcome). We'll see how this pans out.
 
Old 09-16-2012, 09:54 AM   #5
willysr
Senior Member
 
Registered: Jul 2004
Location: Jogja, Indonesia
Distribution: Slackware-Current
Posts: 2,551

Rep: Reputation: 422Reputation: 422Reputation: 422Reputation: 422Reputation: 422
I built vsftpd 3.0.1 using -Current SlackBuild and it's OK here
 
Old 09-16-2012, 12:37 PM   #6
Martinus2u
Member
 
Registered: Apr 2010
Distribution: Slackware
Posts: 345

Original Poster
Rep: Reputation: 56
Strange. I found the linker choking on the command line created with the help of the script vsf_findlibs.sh. The script creates the following output on my system:

Code:
-lwrap
-lnsl
-lnsl
-lcrypt
-lcrypt
-lcrypt
-ldl
-lnsl
-lresolv
-lutil
/lib/libcap.so.2
-lssl -lcrypto
I had to replace "/lib/libcap.so.2" by "-lcap" to make it work. I'm on x86_64 and gcc-4.7.1_multilib-x86_64-1fix1_alien.

PS: just as I re-read my post it suddenly occurs to me that the missing $LIBDIRSUFFIX might be the problem.
PPS: confirmed

Last edited by Martinus2u; 09-16-2012 at 12:47 PM. Reason: *facepalm*
 
Old 09-18-2012, 02:48 PM   #7
Martinus2u
Member
 
Registered: Apr 2010
Distribution: Slackware
Posts: 345

Original Poster
Rep: Reputation: 56
for those interested, there was another seccomp issue which has now been fixed upstream by version 3.0.2.

Regarding the build issue, it only occurs in a multilib environment. The correct way of fixing it is to replace all occurrences of /lib/ by /lib$LIBDIRSUFFIX/ in vsf_findlibs.sh, and by exporting the environment variable LIBDIRSUFFIX in the Slackbuild. But as I said, it only really causes a build problem in a multilib environment, not in the Slackware binary distribution.

Marking issue as solved.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] file-5.05 breaking certwatch on current ulyx Slackware 1 02-10-2011 12:37 PM
[SOLVED] Very Secure FTP (vsftpd) is refusing to start on Slackware Current WhisperiN Linux - Server 12 12-15-2009 12:29 AM
Displaying current FTP connections munk78 Linux - Networking 1 06-07-2006 05:13 AM
VSFTPD - Extended sessions seem to be breaking user passwds/credentials eviser Linux - Software 1 05-26-2006 10:48 AM
vsftpd & ssl - how do I tell if it's actually vsftpd maintaining the connections?? hunterhunter Linux - General 0 03-27-2006 04:41 PM


All times are GMT -5. The time now is 06:59 PM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration