Posts Tagged ‘www data’

How to list and delete mail queue on Qmail / Sendmail / Postfix and Exim SMTP server

Wednesday, April 3rd, 2013

How to list and manage delete Qmail Postfix Sendmail Exim mail SMTP queue View-and delete manage Linux and FreeBSD mail server queue

I have to administrate different kind of mail servers. Different clients has different requirements so in daily job I had to take care for all major mail server platforms our there. Often I have to fix problems with mail servers one very useful thing is to check the mail server queue to see what is there holding to be delivered. Often problems with busy mail servers are rooted in overfilled queues with undelivered mails so checking the queue on Postfix / Exim / Sendmail and Qmail is among the first thing to do to diagnose a problem with improperly working SMTP. In this little article I will show how one can check what is in the queue even if he didn't have the technical background on how each of those mail delivery agents works.

1. How to check and manage queue of Qmail Mail Server

Essential info on how many messages are in the queue and to list this messages in Qmail are done with qmail-qstat and qmail-qread.

a) Checking how many messages are in Qmail queue undelivered to remote SMTPs

root@mail:~# qmail-qstat
messages in queue: 1
messages in queue but not yet preprocessed: 0

b) Listing undelivered e-mails held in Qmail queue

root@mail:~# qmail-qread
26 Mar 2013 01:33:07 GMT  #9609259  748  <info@pomoriemonastery.org>
    remote    bpfejd@gprizm.com
root@mail:~#

One other useful command in dealing with Qmail queue is qmail-qread type it and see for yourself what it does.
c) Flushing qmail queue

Use a tiny shell script ( flush_qmail_queue.sh ), deleting all files in /var/qmail/queue/mess – directory where qmail stores undelivered messages in queue.

# ./flush_qmail_queue.sh

Though above script should be working in some cases, where there are permission problems with Queue or some other mess it is better to use more sophisticated Qmail Queue cleaining tool Qmail MailRemove. To use its necessary to have a working version of Python programming language. Once downloaded Qmail MailRemove, mkdir  /var/qmail/queue/filter (a directory needed for MailRemove to work). Then run script

# ./mailRemove.py email_to_remove

Other variant to clean messed qmail queue is to use qmailHandle.

2. How to check and delete mails from queue in Postfix SMTP

On postfix queue is checked using both postqueue command which is postfix's specific tool for viewing the queue or the standard sendmail mailq. mailq is actually – Postfix to sendmail compitability interface, i.e. this command is not the native way to view queue in Postfix but is just a wrapper binary which invokes postqueue with an option to visualize what is in queue for SMTP admins accustomed to work with sendmail.

a) Checking list of undelivered e-mails

Below is an examples:

mail:~# mailq

-Queue ID- –Size– —-Arrival Time—- -Sender/Recipient——-
4A22BBE1A3*     657 Mon Apr  1 18:46:01  www-data@debian.uk2net.com
                                         csacpabb@nasvalke.com

25824BE18B*     660 Thu Mar 28 18:15:03  www-data@debian.uk2net.com
                                         Aliermarl@fmailxc.com.com

D2AA7BE1BF      652 Sun Mar 31 04:30:21  www-data@debian.uk2net.com
(host mail.drugsellr.com[37.1.218.81] refused to talk to me: 421 Too many concurrent SMTP connections; please try again later.)
                                         Erudge@drugsellr.com

mail:~# postfix -p
-Queue ID- –Size– —-Arrival Time—- -Sender/Recipient——-
36911BE18D*     662 Mon Mar 25 11:08:01  www-data@debian.uk2net.com
                                         lutuaslenty@fmailxc.com.com

C2439BE207*     662 Fri Mar 22 14:59:45  www-data@debian.uk2net.com
                                         Gavepolla@fmailxc.com.com

4A22BBE1A3*     657 Mon Apr  1 18:46:01  www-data@debian.uk2net.com
                                         csacpabb@nasvalke.com

b) Checking the  number of undelivered mails living in Postfix queue

postfix:~#  postqueue -p|wc -l
433

c) Viewing content of specific mail held in Postfix queue

Whether you need to check content of specific undelivered mail kept in queue you should do it by its ID, to view last mail from earlier postfix -p example:

postfix:~# postcat -q 4A22BBE1A3

*** ENVELOPE RECORDS deferred/A/4A22BBE1A3 ***
message_size:             656             187               1               0             656
message_arrival_time: Tue Apr  2 14:25:34 2013
create_time: Tue Apr  2 14:25:35 2013
named_attribute: rewrite_context=local
sender_fullname: www-data
sender: www-data@debian.uk2net.com
*** MESSAGE CONTENTS deferred/A/4A22BBE1A3 ***
Received: by postfix (Postfix, from userid 33)
        id AA379BE07A; Tue,  2 Apr 2013 14:25:34 +0100 (BST)
To: hawtiene@drugsellr.com
Subject: =?UTF8?B?QWNjb3VudCBpbmZvcm1hdGlvbiBmb3IgU09DQ0VSRkFNRQ==?=
X-PHP-Originating-Script: 1000:register_login_functions.php
From: SOCCERFAME <no-reply@mail.host.com>
Content-type:text/plain; charset=UTF8
Message-Id: <20130402132535.AA379BE07A@mail.host.com>
Date: Tue,  2 Apr 2013 14:25:34 +0100 (BST)

Please keep that email. It contains your username and password for postfix.
—————————-
nick : hawtiene
pass : 1v7Upjw3nT
—————————-

*** HEADER EXTRACTED deferred/A/4A22BBE1A3 ***
original_recipient: hawtiene@drugsellr.com
recipient: hawtiene@drugsellr.com
*** MESSAGE FILE END deferred/A/4A22BBE1A3 ***

d) Deleting mails in Postfix queue

To delete all mails in Postfix queue run:

postfix:~# postsuper -d ALL

If Postfix cannot deliver a message to a recipient it is placed in the deferred queue.  The queue manager will scan the deferred queue to see it if can place mail back into the active queue.  How often this scan occurs is determined by the queue_run_delay.
The queue_run_delay is by default 300s or 300 seconds. If you have a very busy mail server you may see a large deferred queue.
To delete all mails in deferred queue.

postfix:~# postsuper -d ALL deferred

3. How to check mail queue of Exim mail server

Viewing number of messages and list of undelivered messages in Exim queue is done using exim command by specifying arguments.

a) Checking the list of undelivered mails kept undelivered in Exim SMTP Queue

 

root@iqtestfb:/etc/exim4# exim -bp

4d 416 1UI1fS-00021I-1s <root@ETC_MAILNAME> *** frozen *** hipo@pc-freak.net 4d 746 1UI1gc-00023T-0S <root@ETC_MAILNAME> *** frozen *** root@ETC_MAILNAME 4d 752 1UI1lR-0003H0-89 <root@ETC_MAILNAME> *** frozen *** root@ETC_MAILNAME 4d 894 1UI1lR-0003H5-I6 <www-data@ETC_MAILNAME> *** frozen *** www-data@ETC_MAILNAME

b) Counting number of Exim undelivered messages kept in Mail Queue
exim-smtp:/etc/exim4# exim -bpc 2063 c) Getting a summary of all messages in Exim Queue (Count, Volume, Oldest, Newest, Destination Domain)
exim-smtp:/etc/exim4# exim -bp| exiqsumm

Count Volume Oldest Newest Domain —– —— —— —— —— 1 862 22h 22h 126.com 2 1751 12h 5h 163.com 21 3111KB 4d 3h abv.bg 2 766KB 42h 7h alice.it 1 383KB 7h 7h aol.com 1 383KB 4d 4d att.net 1 383KB 3d 3d beotel.net 2 766KB 20h 19h bih.net.ba 1685 3291KB 4d 1m etc_mailname 1 383KB 70h 70h facebook.com 1 383KB 66h 66h gaaa 81 22MB 4d 15m gmail.com 1 564 3d 3d gmaill.com 1 383KB 3d 3d googlemail.com 1 383KB 64h 64h hotmai.rs 33 10MB 4d 2h hotmail.com 25 9193KB 4d 79m hotmail.it 1 383KB 4d 4d hotmailcom 2 1128 24h 20h icloud.com 2 766KB 67h 67h inwind.it 11 3831KB 3d 7h libero.it 1 383KB 20h 20h live.co.uk 3 767KB 37h 3h live.com 6 1916KB 67h 45h live.it 1 552 28h 28h live.no 1 383KB 67h 67h llle.it 1 383KB 67h 67h lllle.it 1 383KB 33m 33m luigimori.it 2 389KB 56h 4h mail.bg 1 383KB 66h 66h mailmetrash.com 1 383KB 39h 39h malltron.it 1 562 7h 7h me.com 1 383KB 4d 4d msn.com 2 1116 49h 47h net.hr 1 383KB 28h 28h orion.rs 1 383KB 3d 3d paskaa.com 75 31KB 4d 3d pc-freak.net 1 572 3d 3d prismamedia.ro 1 383KB 71h 71h rediffmail.com 1 383KB 28h 28h seznam.cz 1 383KB 14m 14m siol.net 36 11KB 4d 3d sms.mtel.net 1 557 53h 53h t-com.hr 1 383KB 23h 23h tecnobagno.191.it 1 383KB 4d 4d teol.net 2 766KB 67h 44h virgilio.it 1 383KB 42h 42h windwslive.com 1 549 3d 3d yahoo 43 9213KB 4d 74m yahoo.com 2 766KB 70h 46h yahoo.it 1 383KB 71h 71h ymail.com ————————————————————— 2068 76MB 4d 1m TOTAL

 

c)  List Exim queued messages sorted by recipient address and sender address

  To list e-mails in queue sorted by recipient address

exim-smtp:/etc/exim4# exim -bpr|grep -Eo "^\s*[^ ]*@[^ ]*$" |sort | uniq -c

To List queued messages grouped by address of sender
exim-smtp:/etc/exim4# exim -bpr | grep -Eo "<[^ ]*@[^ ]*>" | sort | uniq -c  

d) Forcing Exim  to attempt re-send e-mails kept inside
queue

As Exim is relatively new SMTP its authors thought deeply before writting it and included options to do queue e-mail sent whether server is not under extremely high loads as well as send, regardless of load. Make Exim start sending queue e-mails if server is not overloaded (no extra-high server load)
exim-smtp:/etc/exim4# exim -q -v

  To make Exim force a queue run regardless of system load exim-smtp:/etc/exim4# exim -qf -v  

To make Exim deliver only e-mails sent from server to server (usually e-mails from local server monitoring software and log reports)
exim-smtp:/etc/exim4# exim -ql -v

e) Deleting e-mails from Exim mail queue

To Remove a message from queue identify by ID

exim-smtp:/etc/exim4# exim -Mrm <message-id>     Force Exim delivery of a message regardless of Frozen status

exim-smtp:/etc/exim4# exim -M<message-id >  

f) Removing Exim mails older than certain seconds or hours To remove all mails older than 12hrs (43000 seconds) exim-smtp:~# exiqgrep -o 43000 -i | xargs exim -Mrm

Deleting all frozen mails from queue is done with:

exim-smtp:~# exiqgrep -z -i | xargs exim -Mrm  

Removing all e-mails belonging to particular sender

exim-smtp:~# exiqgrep -i -f user@domain.com | xargs exim -Mrm

  Removing all mails from a sender that are older than 12hrs

exim-smtp:~# exiqgrep -o 43000 -i -f user@domain.com | xargs exim -Mrm
 

g) Flushing Exim mail queue
Use

exim-smtp:~# runq
  or

exim-smtp:~# exim -q

4. How to view and manage sendmail SMTP queue

a) Listing all e-mails stored in Sendmail queue

To list the mail queue in sendmail

sendmail:~# sendmail -bp
/var/spool/mqueue is empty
        Total requests: 0

or

sendmail:~# mailq
 

/var/spool/mqueue (3 requests) —–Q-ID—– –Size– —–Q-Time—– ————Sender/Recipient———– m9TMLQHG012749 1103 Thu Oct 30 11:21 <apache@localhost.localdomain> (host map: lookup (electrictoolbox.com): deferred) <test@electrictoolbox.com> m9TMLRB9012751 37113 Thu Oct 30 11:21 <apache@localhost.localdomain> (host map: lookup (electrictoolbox.com): deferred) <test@electrictoolbox.com> m9TMLPcg012747 240451 Thu Oct 30 11:21 <apache@localhost.localdomain> (host map: lookup (electrictoolbox.com): deferred) <test@electrictoolbox.com> Total requests: 3

b) Checking queue for specific mail sender or recipient

sendmail:~# mailq | grep -i email@domain-name.com -A 2 -B 2
....

c) Removing all e-mails from Sendmail queue

To delete everything stored in Sendmail queue delete files from directory where sendmail stores still undelivered mails. In sendmail this is /var/spool/mqueue and /var/mqueue

sendmail:~# rm /var/spool/mqueue/*.*
sendmail:~# rm /var/mqueue/*.*

Deleting all pending mails from queue

To remove / delete e-mails originating from certain domain / user or recipient

sendmail:~# sendmail -qS -v domain-name.com

To delete e-mail from certain user or recipieint

sendmail:~# sendmail -qR -v yahoo.co.uk

 

How to check what process is listening on network port with: lsof & fuser commands in Linux / BSD

Saturday, March 16th, 2013

It is a common thing for me as a Linux and FreeBSD sysadmin to know what process assignes to which port number? I'm sure many novice system administrators will end up sooner or later with same question. Knowing what kind of processes has listening to TCP and UDP protocol / ports is a must to have a proper configured Linux / BSD system. In Linux there are two commands ( lsof and fuser) with which you can get various extra PID information on running processes (i.e. get information which cannot otherwise be obtained via the usual ps and netstat  To use them on most Linux distributions, you will have to have them installed.

1. Install fuser / lsof on Linux / BSD

a) On RPM based Linux distros – Fedora, CentOS, RHEL, SuSE /sbin/fuser is usually part of base install psmisc rpm package, however /usr/sbin/lsof is not among standard installed rpms, so you have to manually install via yum:

[root@centos ~]# yum install -y lsof
….

b) On Deb based Linuxes (Debian, Ubuntu, Mint, ArchLinux etc.). both lsof and fuser has to be installed via a separate packages non-part of Debian base install packs.

server:~# apt-get --yes install lsof fuser
....

On Debian full path location of both is in /bin/fuser and /usr/bin/lsof.

Two tools are precious swiss army knife outfit to use, whether you doubt someone cracked into a server or in doubt you might have "hidden" cracker processes on server.

c) Install fuser on Free/Net/Open/ BSD

bsd# cd /usr/ports/sysutils/fuser
bsd# make install clean
....
bsd# cd /usr/ports/sysutils/lsof
bsd# make install clean
....

2. Using fuser and lsof to look up process PIDs assigned to port numbers

lsof name is derived from List Open Files, as we know in UNIX, GNU / Linux,  *BSD everything on the system is a file, thus to get all kind of information concerning all active files (i.e. ports, PIDs, procotols and process names;

server:~# lsof +M -i4 | less

COMMAND     PID     USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
portmap    1317   daemon    4u  IPv4     3930      0t0  UDP *:sunrpc[portmapper]
portmap    1317   daemon    5u  IPv4     3939      0t0  TCP *:sunrpc[portmapper] (LISTEN)
rpc.statd  1329    statd    4u  IPv4     3974      0t0  UDP *:657
rpc.statd  1329    statd    6u  IPv4     3983      0t0  UDP *:28530[status]
rpc.statd  1329    statd    7u  IPv4     3986      0t0  TCP *:58515[status] (LISTEN)
apache2    1625 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    1625 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
sshd       1918     root    3u  IPv4     4945      0t0  TCP *:ssh (LISTEN)
miniserv.  2155     root    5u  IPv4     5299      0t0  TCP *:20000 (LISTEN)
miniserv.  2155     root    6u  IPv4     5300      0t0  UDP *:20000
miniserv.  2161     root    6u  IPv4     5367      0t0  TCP *:webmin (LISTEN)
miniserv.  2161     root    7u  IPv4     5368      0t0  UDP *:10000
ntpd       2172      ntp   16u  IPv4     5395      0t0  UDP *:ntp
ntpd       2172      ntp   18u  IPv4     5402      0t0  UDP localhost:ntp
ntpd       2172      ntp   19u  IPv4     5403      0t0  UDP iqtest.soccerfame.com:ntp
ntpd       2172      ntp   20u  IPv4    16028      0t0  UDP secure.broomlake.com:ntp
apache2    4505 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    4505 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    4539 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    4539 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    4780 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    4780 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    4900 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    4900 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    4907 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    4907 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    4915 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    4915 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5067 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5067 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5133 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5133 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5134 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5134 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5148 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5148 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5152 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5152 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5259 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5259 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5265 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5265 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5266 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5266 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5346 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5346 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5356 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5356 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5467 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5467 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5523 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5523 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5568 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5568 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5715 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5715 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5716 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5716 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5758 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5758 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    5789 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    5789 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2    6106 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2    6106 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   16608 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   16608 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   16904 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   16904 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   17124 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   17124 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   17280 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   17280 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   20855 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   20855 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   20920 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   20920 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   21023 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   21023 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   22182 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   22182 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23307 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23307 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23366 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23366 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23408 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23408 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23419 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23419 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23428 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23428 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23452 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23452 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23561 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23561 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23579 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23579 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   23851 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   23851 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   24103 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   24103 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   24659 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   24659 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
sshd      25073     root    3u  IPv4 29855891      0t0  TCP iqtest.soccerfame.com:ssh->pc-freak.net:50176 (ESTABLISHED)
sshd      25084     hipo    3u  IPv4 29855891      0t0  TCP iqtest.soccerfame.com:ssh->pc-freak.net:50176 (ESTABLISHED)
apache2   25089 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   25089 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   26737 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   26737 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   27243 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   27243 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   27282 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   27282 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   27633 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   27633 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   28205 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   28205 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   29244 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   29244 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   29372 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   29372 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   29411 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   29411 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   29462 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   29462 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   29548 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   29548 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   30161 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   30161 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   31876 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   31876 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   31958 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   31958 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   32052 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   32052 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   32061 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   32061 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   32143 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   32143 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   32149 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   32149 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   32440 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   32440 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   32635 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   32635 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   32790 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   32790 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   40211 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   40211 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   40309 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   40309 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   40432 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   40432 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   40476 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   40476 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46319     root    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46319     root    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46438 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46438 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46439 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46439 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46440 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46440 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46441 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46441 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46442 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46442 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46443 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46443 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46509     root    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46509     root    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46510     root    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46510     root    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   46515     root    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   46515     root    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   51287 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   51287 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   51485 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   51485 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   51804 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   51804 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
named     54418     bind   20u  IPv4 31298857      0t0  TCP localhost:domain (LISTEN)
named     54418     bind   21u  IPv4 31298859      0t0  TCP iqtest.soccerfame.com:domain (LISTEN)
named     54418     bind   22u  IPv4 31298861      0t0  TCP secure.broomlake.com:domain (LISTEN)
named     54418     bind   23u  IPv4 31298865      0t0  TCP localhost:953 (LISTEN)
named     54418     bind  512u  IPv4 31298856      0t0  UDP localhost:domain
named     54418     bind  513u  IPv4 31298858      0t0  UDP iqtest.soccerfame.com:domain
named     54418     bind  514u  IPv4 31298860      0t0  UDP secure.broomlake.com:domain
named     54418     bind  515u  IPv4 31298864      0t0  UDP *:domain
proftpd   62010  proftpd    1u  IPv4 31306260      0t0  TCP *:ftp (LISTEN)
mysqld    62420    mysql   11u  IPv4 31306903      0t0  TCP *:mysql (LISTEN)
apache2   62582 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   62582 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   62845 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   62845 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)
apache2   64748 www-data    3u  IPv4     5456      0t0  TCP *:www (LISTEN)
apache2   64748 www-data    4u  IPv4     5458      0t0  TCP *:https (LISTEN)

Above lsof command lists all active listening processes port number on UDP and TCP/IP 4 proto with the assigned process PID number (in second column). This is very useful if you find out to have listening service on port number and you cannot figure out what process name exactly is listening.

A classic example, where this is very helpful is if you have a listening process on SMTP port 25 and you cannot identify what kind of mail server is taking up the port? This has happened me many times on Debian Linux based hosts, which by default had priorly installed sendmail and I later removed sendmail to install Postfix or Exim SMTP.
To find out what is assigning port 25, you had to grep the protocol name from all binded host processes, like so:

 

server:~# lsof +M -i4 | grep -i smtp

exim4     17550     root    3u  IPv4 31577966      0t0  TCP localhost:smtp (LISTEN)

Whether you want to get information on Process ID, binding other random port lets say port 10000, following same logic you can grep it:

server:~# lsof +M -i4 |grep -i 10000
miniserv.  2161     root    7u  IPv4     5368      0t0  UDP *:10000

To get rid of a process for which you're unsure what kind of (/etc/init.d/service-name) init script is starting it, you can then use kill cmd to stop it;

server:~# kill -9 2161

Second approach to find out what kind of process is listening on a random port or socket, lets say port num 58515 is by using fuser.

 

 

server:~# netstat -ltn4
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State     
tcp        0      0 0.0.0.0:3306            0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:10000           0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:58515           0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:21              0.0.0.0:*               LISTEN    
tcp        0      0 77.92.85.71:53          0.0.0.0:*               LISTEN    
tcp        0      0 109.123.106.44:53       0.0.0.0:*               LISTEN    
tcp        0      0 127.0.0.1:53            0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN    
tcp        0      0 127.0.0.1:953           0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN    
tcp        0      0 0.0.0.0:20000           0.0.0.0:*               LISTEN    

Below netstat cmmand, lists all active listening processes on respective IP address and port for protocol TCPIP v.4.

Hence on to get more information on what process is listening on port 58515?

server:~#  fuser -v 58515/tcp

                     USER        PID ACCESS COMMAND
58515/tcp:           statd      1329 F…. rpc.statd

Once you know what is listening, whether you want to kill it this is also possible directly through fuser;

 

server:~# fuser -vk 58515/tcp

As a close-up, I will say fuser and lsof are two must have software tools on any productive server. It is among the critical applications admin has to install during initial server set-up. fuser and lsof helps me often in my sysadmin work, it was more than once I've used them to identify script-kiddies exploit scanners running as a standard process names, as well secretly listening on weird port number  cracker back-doors.

Hopefully this little article, helps someone learn something new. Plenty is written and will be written and if one takes the time to research he can learn much, much more. I'm sure my tiny article is nothing new under the sun for old-school admins, I still hope it will be of use to novice. I'm looking forward to hear if I'm missing some neat use or some interesting case, when lsof or fuser "saved your ass" 🙂
 

How to solve “[crit] [client xxx.xxx.xxx.xxx] (13)Permission denied: /var/lib/ejabberd/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable, referer: http://jabber.mydomain.com/” – Error Cause and Solution

Thursday, January 5th, 2012

While configuring JWchat domain, I've come across around an error:

pcfg_openfile: unable to check htaccess file, ensure it is readable

The exact error I got in /var/log/apache2/error.log looked like so:

[crit] [client xxx.xxx.xxx.xxx] (13)Permission denied: /var/lib/ejabberd/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable, referer: http://jabber.mydomain.com/

The error message suggested /var/lib/ejabberd/.htaccess – is missing or not readable, however after checking i've seen .htaccess existed as well as was readable:

debian:~# ls -al /var/lib/ejabberd/.htaccess
-rw-r--r-- 1 www-data www-data 114 2012-01-05 07:44 /var/lib/ejabberd/.htaccess

At first glimpse it seems like the message is misleading and not true, however when I switched to www-data user (the user with which Apache runs on Debian), I've figured out the error meaning of unreadability is exactly correct:

www-data@debian:$ ls -al /var/lib/ejabberd/.htaccess
ls: cannot access /var/lib/ejabberd/.htaccess: Permission denied

This permission denied was quite strange, especially when considering the .htaccess is readable for all users:

debian:~# ls -al /var/lib/ejabberd/.htaccess
-rw-r--r-- 1 www-data www-data 114 2012-01-05 07:44 /var/lib/ejabberd/.htaccess

After a thorough look on what might go wrong, thanksfully I've figured it out. The all issues were caused by wrong permissions of /var/lib/ejabberd/.htaccess .You can see below the executable flag for all users (including apache's www-data) is missing :

debian:/var/lib# ls -ld /var/lib/ejabberd/drw-r--r-- 3 ejabberd ejabberd 4096 2012-01-05 07:45 /var/lib/ejabberd/

Solving the error, hence is as easy as adding +x flag to /var/lib/ejabberd :

debian:/var/lib# chmod +x /var/lib/ejabberd

Another way to fix the error is to chmod to 755 to the directory which holds .htaccess:

From now onwards pcfg_openfile: unable to check htaccess file, ensure it is readable err is no more 😉

Fix of “Unable to allocate memory for pool.” PHP error messages

Saturday, October 15th, 2011

Since some time, I don’t know exactly where, after some updates of my WordPress running on a small server with FreeBSD 7.2. I’ve started getting a lot of Apache crashes. Often the wordpress scripts stopped working completely and I got only empty pages when trying to process the wordpress blog in a browser.

After a bunch of reading online, I’ve figured out that the cause might be PHP APC stands for Alternative PHP Cache .

I was not sure if the PHP running on the server had an APC configured at all so I used a phpinfo(); script to figure out if I had it loaded. I saw the APC among the loaded to show off in the list of loaded php modules, so this further led me to the idea the APC could be really causing the unexpected troubles.

Thus first I decided to disable the APC on a Virtualhost level for the domain where the crashing wordpress was hosted, to do I placed in the VirtualHost section in the Apache configuration /usr/local/etc/apache2/httpd.conf the following config directive:

php_flag apc.cache_by_default Off

These get me rid of the multiple errors:

PHP Warning: require_once() [function.require-once]: Unable to allocate memory for pool. in /usr/local/www/data-dist/blog/wp-content/plugins/tweet-old-post/top-admin.php on line 6

which constantly were re-occuring in php_error.log:

Further after evaluating all the websites hosted on the server and making sure none of which was really depending on APC , I’ve disabled the APC completely for PHP. To do so I issued:

echo 'apc.enabled = 0' >> /usr/local/etc/php.ini

Similarly on GNU/Linux to disable globally APC from PHP only the correct location to php.ini should be provided on Debian this is /etc/php5/apache2/php.ini .

Fix to Nagios is currently not checking for external commands

Wednesday, August 24th, 2011

While I was deploying a new Nagios install to Monitor some Windows hosts I’ve came across the following error in Nagios’s web interface:

Sorry, but Nagios is currently not checking for external commands, so your command will not be committed!
Read the documentation for information on how to enable external commands...

This error is caused by an option configuration for /etc/nagios/nrpe.cfg (part of the nrpe-nagios-server Debian package.

The config variable in nrpe.cfg causing the error is check_external_command=0 , the fix comes to changing the variable to:

check_external_command=1

As well as restart the /etc/init.d/nagios-nrpe-server and /etc/init.d/nagios3 services:

debian:~# /etc/init.d/nagios3 restart
...
debian:~# /etc/init.d/nagios-nrpe-server
...

This changes has work out the error Sorry, but Nagios is currently not checking for external commands, so your command will not be committed! , however immediately after another kind of error appared in Nagios web interface when I tried to use the send Nagios commands button. The error was:

Error: Could not stat() command file '/var/lib/nagios3/rw/nagios.cmd'!

This error is due to a deb package, which seems to be affecting the current deb versions of Nagios shipped with Debian 6 Squeeze stable, as well as the Latest Ubuntu release 11.04.

Thanksfully there is a work around to the problem I found online, to fix it up I had to execute the commands:

debian:~# /etc/init.d/nagios3 stop debian:~# dpkg-statoverride --update --add nagios www-data 2710 /var/lib/nagios3/rw
debian:~# dpkg-statoverride --update --add nagios nagios 751 /var/lib/nagios3
debian:~# /etc/init.d/nagios3 start

And hooray Thanks God the error is gone 😉

wordpress & awstats

Wednesday, July 29th, 2009

awstats-logo and wordpress awstats

I'm planning to bring up a website for remote system administration for quite some time 'till now.A couple of days before I've installed wordpress and used the monochrome theme in combination with a couple of plugins.I've used the WordPress, "Contact Form 7" plugin. I struggled around for a day before I realize the way it's beeingembeded into the Page post. Amri (Marto) a friend of mine helped me up with the whole deal, it came to be as simple assimply adding [contact-form 1 "My feedback" to one of the pages I've created in wordpress. There were a bunch of things on my newlycreated wordpress blog that looked more like a blog than a page which was not my initial goal and therefore I had to remove some chunksof code from some of the php files that came with the monochrome theme. I've partially used a guide called
"How to create Websites using WordPress" which probably would be of an interest to you if you're trying to make wordpress look more like a website than a blog, check it out here . Amri suggested few plugins that would add up to my current wordpress installation.
This are:
Cyr2Lat Slugs
Google XML Sitemaps Generates sitemap.xml. Gives an option to setup Google WebMaster Tools and in that manner of thoughts ads up for faster indexing of the blog
All In One SEO pack – SEO instrument that optimizes your wordpress
Belavir – Tracks the changes in files in wordpress.
In my case I couldn't make the Google XML Sitemap work correctly. Probably because I've removed bits of php code from some main php pages.Anyways I was able to make my wordpress look like a normal website and in general it might be said that it looks quite decent now if I have to compare it with my previous websites I've built like let's say my home page pc-freak.net . I've plans to deliver remote system administration services to the masses via my Yet Another Cheap System Administration Services.
I've also installed awstats on the pcfreak box currently running on
a nice foxy IBM machine. To properly install and run the Awstats I've used fractions from the article Install Awstats on FreeBSD . What was different in my case was:
1. I had to cd /usr/ports/www/awstats/work/awstats-6.9/tools/; run ./awstats_configure.pl. Answer a couple of questions. I've initially installed awstats configurations to /etc/awstats after which I've moved it to /usr/local/etc/awstats .
2. I had to create /var/lib/awstats where awstats stores it's database files: mkdir /var/lib/awstats
3. I had to link awstats to the location where my cgi-bin dir was set up by httpd.conf: ln -sf /usr/local/www/awstats/cgi-bin/ /usr/local/www/cgi-bin/awstats
4. I had to create a link to make the awstats icons visualize: ln -sf /usr/local/www/awstats/icons /usr/local/www/data/awstatsicons
5. I had to edit my conf file and align it with my desires, most important to note is the requirement to change the location to my Apache log file in my case that was /var/log/httpd-access.log: Change LogFile value in /usr/local/etc/awstats/awstats.pc-freak.net.conf I've changed it to LogFile="/var/log/httpd-access.log"
6. Next I had to execute the following to generate statistics for my domain pc-freak.net: /usr/local/www/awstats/cgi-bin/awstats.pl -update -config=pc-freak.net
7. Edit the root user crontab (crontab -u root -e) and paste the following : 01 0 * * * /usr/local/www/awstats/cgi-bin/awstats.pl -update -config=pc-freak.net 2>&1 >/dev/null8. Change the default Directory settings for /usr/local/www/cgi-bin. Had to changed them to the following AllowOverride FileInfo AuthConfig Limit Indexes Options FollowSymLinks ExecCGI Order allow,deny Allow from all
9. After that I've protected my awstats with a pass putting /usr/local/awstats/cgi-bin/.htaccess file containing the followingAuthType BasicAuthName "Restricted Access"AuthUserFile /usr/local/etc/apache2/myawstats.passwdRequire user admin
10. And last but not least, had to create the myawstats.passwd with the following command: htpasswd -c /usr/local/etc/apache2/myawstats.passwd admin

Right after I happily accessed my newly installed awstats via my domain http://pc-freak.net/cgi-bin/awstats/awstats.pl END—–