Fail2ban Status commands

fail2ban-client status postfix

Show status of all fail2ban jails at once
create the file fail2ban-allstatus.sh
#!/bin/bash
JAILS=`fail2ban-client status | grep Jail list | sed -E s/^[^:]+:[ \t]+// | sed s/,//g`
for JAIL in $JAILS
do
fail2ban-client status $JAIL
done

or with a command

fail2ban-client status|awk -F: ‘/Jail list:/ { split($2,jail,”,”) ; for (i in jail) { gsub(/[\t ]/,””,jail[i]); system(“fail2ban-client status “jail[i]); }; }’

grep -srni “journalmatch” /etc/fail2ban/filter.d/

 

Install and configure Milter Manager

Install to CentOS 7

Install to CentOS 7 — How to install milter manager to CentOS 7

About this document

This document describes how to install milter manager to CentOS 7. See Install for general install information.

In this document, CentOS 7.6 is used. Sudo is used to run a command with root privilege. If you don’t use sudo, use su instead.

Install packages

Postfix is used as MTA because it’s installed by default.

Spamass-milter, clamav-milter and milter-greylist are used as milters. Milter packages registered in EPEL are used.

Register EPEL like the following:

% sudo yum install -y epel-release

Now, you install milters:

% sudo yum install -y spamass-milter-postfix clamav-scanner-systemd clamav-update clamav-milter clamav-milter-systemd milter-greylist

And you install RRDtool for generating graphs:

% sudo yum install -y rrdtool

Build and Install

milter manager can be installed by yum.

Register milter manager yum repository like the following:

% curl -s https://packagecloud.io/install/repositories/milter-manager/repos/script.rpm.sh | sudo bash

See also: <URL:https://packagecloud.io/milter-manager/repos/install>

Now, you install milter manager:

% sudo yum install -y milter-manager

Configuration

Here is a basic configuration policy.

milter-greylist should be applied only if S25R condition is matched to reduce needless delivery delay. But the configuration is automatically done by milter manager. You need to do nothing for it.

It’s difficult that milter manager runs on SELinux. Disable SELinux policy module for Postfix and Milter.

% sudo semodule -d postfix
% sudo semodule -d milter

Configure spamass-milter

At first, you configure spamd.

spamd adds “[SPAM]” to spam mail’s subject by default. If you don’t like the behavior, edit /etc/mail/spamassassin/local.cf.

Before:

rewrite_header Subject [SPAM]

After:

# rewrite_header Subject [SPAM]

Add the following configuration to /etc/mail/spamassassin/local.cf. This configuration is for adding headers only if spam detected.

remove_header ham Status
remove_header ham Level

Start spamd on startup:

% sudo systemctl enable spamassassin

Start spamd:

% sudo systemctl start spamassassin

Here are spamass-milter’s configuration items:

  • Disable needless body change feature.
  • Reject if score is larger than or equal to 15.

Change /etc/sysconfig/spamass-milter:

Before:

#EXTRA_FLAGS="-m -r 15"

After:

EXTRA_FLAGS="-m -r 15"

Start spamass-milter on startup:

% sudo systemctl enable spamass-milter

Start spamass-milter:

% sudo systemctl start spamass-milter

Configure clamav-milter

Update ClamAV virus database and start clamd.

Edit /etc/freshclam.conf like the following. It comments out “Example”, changes “NotifyClamd” value and uncomments other items.

Before:

Example
#LogFacility LOG_MAIL
#NotifyClamd /path/to/clamd.conf

After:

#Example
LogFacility LOG_MAIL
NotifyClamd /etc/clamd.d/scan.conf

Run freshclam by hand at the first time:

% sudo freshclam

Configure clamd.

Edit /etc/clamd.d/scan.conf like the following. It comments out “Example” and uncomments other items:

Before:

Example
#LogFacility LOG_MAIL
#LocalSocket /run/clamd.scan/clamd.sock

After:

#Example
LogFacility LOG_MAIL
LocalSocket /run/clamd.scan/clamd.sock

Start clamd on startup:

% sudo systemctl enable [email protected]

Start clamd:

% sudo systemctl start [email protected]

Configure clamav-milter.

Edit /etc/mail/clamav-milter.conf like the following. It comments out “Example”, change “ClamdSocket” value and uncomments other items:

Before:

Example
#MilterSocket /run/clamav-milter/clamav-milter.socket
#MilterSocketMode 660
#ClamdSocket tcp:scanner.mydomain:7357
#LogFacility LOG_MAIL

After:

#Example
MilterSocket /run/clamav-milter/clamav-milter.socket
MilterSocketMode 660
ClamdSocket unix:/run/clamd.scan/clamd.sock
LogFacility LOG_MAIL

Add “clamilt” user to “clamscan” group to access clamd’s socket:

% sudo usermod -G clamscan -a clamilt

Start clamav-milter on startup:

% sudo systemctl enable clamav-milter

Start clamav-milter:

% sudo systemctl start clamav-milter

Configure milter-greylist

Change /etc/mail/greylist.conf for the following configurations:

  • use the leading 24bits for IP address match to avoid Greylist adverse effect for sender uses some MTA case.
  • decrease retransmit check time to 10 minutes from 30 minutes (default value) to avoid Greylist adverse effect.
  • increase auto whitelist period to a week from 1 day (default value) to avoid Greylist adverse effect.
  • don’t use Greylist when trusted domain passes SPF. (Trusted domains are configured in milter manager)
  • use Greylist by default.

The configuration relaxes Greylist check to avoid Greylist adverse effect. It increases received spam mails but you should give priority to avoid false positive rather than false negative. You should not consider that you blocks all spam mails by Greylist. You can blocks spam mails that isn’t blocked by Greylist by other anti-spam technique such as SpamAssassin. milter manager helps constructing mail system that combines some anti-spam techniques.

Before:

socket "/run/milter-greylist/milter-greylist.sock"
# ...
racl whitelist default

After:

socket "/run/milter-greylist/milter-greylist.sock" 660
# ...
subnetmatch /24
greylist 10m
autowhite 1w
sm_macro "trusted_domain" "{trusted_domain}" "yes"
racl whitelist sm_macro "trusted_domain" spf pass
racl greylist sm_macro "trusted_domain" not spf pass
racl greylist default

Start milter-greylist on startup:

% sudo systemctl enable milter-greylist

Start milter-greylist:

% sudo systemctl start milter-greylist

Configure milter manager

Add “milter-manager” user to “clamilt” group to access clamav-milter’s socket:

% sudo usermod -G clamilt -a milter-manager

Add “milter-manager” user to “mail” group and “grmilter” group to access milter-greylist’s socket:

% sudo usermod -G mail -a milter-manager
% sudo usermod -G grmilter -a milter-manager

Add “milter-manager” user to “postfix”” group to access spamass-milter’s socket:

% sudo usermod -G postfix -a milter-manager

milter manager detects milters that installed in system. You can confirm spamass-milter, clamav-milter and milter-greylist are detected:

% sudo /usr/sbin/milter-manager -u milter-manager -g milter-manager --show-config

The following output shows milters are detected:

...
define_milter("milter-greylist") do |milter|
  milter.connection_spec = "unix:/run/milter-greylist/milter-greylist.sock"
  ...
  milter.enabled = true
  ...
end
...
define_milter("clamav-milter") do |milter|
  milter.connection_spec = "unix:/var/run/clamav-milter/clamav-milter.socket"
  ...
  milter.enabled = true
  ...
end
...
define_milter("spamass-milter") do |milter|
  milter.connection_spec = "unix:/run/spamass-milter/postfix/sock"
  ...
  milter.enabled = true
  ...
end
...

You should confirm that milter’s name, socket path and “enabled = true”. If the values are unexpected, you need to change /etc/milter-manager/milter-manager.local.conf. See Configuration for details of milter-manager.local.conf.

But if we can, we want to use milter manager without editing miter-manager.local.conf. If you report your environment to the milter manager project, the milter manager project may improve detect method.

milter manager’s configuration is finished.

Start to milter manager on startup:

% sudo systemctl enable milter-manager

Start to milter manager:

% sudo systemctl start milter-manager

milter-test-server is usuful to confirm milter manager was ran:

% sudo -u milter-manager milter-test-server -s unix:/var/run/milter-manager/milter-manager.sock

Here is a sample success output:

status: accept
elapsed-time: 0.128 seconds

If milter manager fails to run, the following message will be shown:

Failed to connect to unix:/var/run/milter-manager/milter-manager.sock

In this case, you can use log to solve the problem. milter manager is verbosily if –verbose option is specified. milter manager outputs logs to standard output if milter manager isn’t daemon process.

You can add the following configuration to /etc/sysconfig/milter-manager to output verbose log to standard output:

OPTION_ARGS="--verbose --no-daemon"

Restart milter manager:

% sudo systemctl restart milter-manager

Some logs are output if there is a problem. Running milter manager can be exitted by Ctrl+c.

OPTION_ARGS configuration in /etc/sysconfig/milter-manager should be commented out after the problem is solved to run milter manager as daemon process. And you should restart milter manager.


Configure Postfix

Enables Postfix:

% sudo systemctl enable postfix
% sudo systemctl start postfix

Configure Postfix for milters. Append following lines to /etc/postfix/main.cf:

milter_protocol = 6
milter_default_action = accept
milter_mail_macros = {auth_author} {auth_type} {auth_authen}

For details for each lines.

milter_protocol = 6Use milter protocol version 6.
milter_default_action = acceptMTA receives mails when MTA cannot access milter. Although there are problems between MTA and milter, MTA can deliver mails to clients. But until you recover milter, perhaps MTA receives spam mails and virus mails.

If you can recover the system quickly, you can specify ‘tempfail’ instead of ‘accept’. Default value is ‘tempfail’.

milter_mail_macros = {auth_author} {auth_type} {auth_authen}MTA gives information related SMTP Auth to milters. milter-greylist etc. uses it.

Register milter manager to Postfix. It’s important that spamass-milter, clamav-milter and milter-greylist aren’t needed to be registered because they are used via milter manager.

Append following lines to /etc/postfix/main.cf:

smtpd_milters = unix:/var/run/milter-manager/milter-manager.sock

Reload Postfix’s configuration.

% sudo systemctl reload postfix

milter manager logs to syslog. If milter manager works well, some logs can be shown in /var/log/maillog. You need to send a test mail for confirming.

Conclusion

There are many configurations to work milter and Postfix together. They can be reduced by introducing milter manager.

Without milter manager, you need to specify sockets of spamass-milter, clamav-milter and milter-greylist to /etc/postfix/main.cf. With milter manager, you don’t need to specify sockets of them, just specify a socket of milter manager. They are detected automatically. You don’t need to take care some small mistakes like typo.

milter manager also detects which ‘/sbin/chkconfig -add’ is done or not. If you disable a milter, you use the following steps:

% sudo systemctl stop milter-greylist
% sudo systemctl disable milter-greylist

You need to reload milter manager after you disable a milter.

% sudo systemctl reload milter-manager

milter manager detects a milter is disabled and doesn’t use it. You don’t need to change /etc/postfix/main.cf.

You can reduce maintainance cost by introducing milter manager if you use some milters on CentOS.

milter manager also provides tools to help operation. Installing them is optional but you can reduce operation cost too. If you also install them, you will go to Install to CentOS (optional) .

Yum warning

After a yum update I receive this worning :

warning: /etc/fail2ban/jail.conf created as /etc/fail2ban/jail.conf.rpmnew

Those warnings are expected if you have made changes to your configuration files. yum is kind enough to not overwrite your existing modified configuration, but instead writes the new default configuration file to a .rpmnew file, which you can then review and perhaps incorporate the new defaults etc to your own configuration. This is OK. The kernel module warnings are also of no concern.

 

Virtual Box resize disk space

  • Go into settings of the VirtualBox console manager and go into Storage settings. Copy the position path of your current controller. The file can be *.vdi or *.vmdk or others.
  • Shut down VirtualBox again.
  • Make a copy of the VDI file – just in case (“C:\Users\Administrator\VirtualBox VMs\vm\Windows10TeamSystem-disk1.vdi” -> “C:\Users\Administrator\VirtualBox VMs\vm\Windows10TeamSystem-disk1Copy.vdi“)
  • Go into the Windows command prompt (Start->type “cmd” into the box)
  • cd C:\Users\Administrator\VirtualBox VMs\vm\ the location of the VDI file that you wish to resize.
  • At the Windows command prompt, type:
  • D:\>"C:\Program Files\Oracle\VirtualBox\VBoxmanage" modifyhd Windows10TeamSystem-disk1.vdi --resize 358400
    this will re-size the drive to 350 GB(1024 * 350 = 358400). Pick a value that suits you. Note, your vdi file will not change in size at this point. The output should look like:
    0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
  • Enlarge the Virtual Machine’s Partition

    You now have a larger virtual hard disk. However, the operating system’s partition on your virtual hard disk is the same size, so you won’t be able to access any of this space yet.

  • You’ll now need to extend the guest operating system’s partition as if you were enlarging a partition on a real hard disk in a physical computer. You can’t enlarge the partition while the guest operating system is running, just as you can’t enlarge your C:\ partition while Windows is running on your computer.You can use a GParted live CD to resize your virtual machine’s partition – simply boot the GParted ISO image in your virtual machine and you’ll be taken to the GParted partition editor in a live Linux environment. GParted will be able to enlarge the partition on the virtual hard disk.First, download the GParted live CD’s ISO file from here.Load the ISO file into your virtual machine by going into the virtual machine’s settings window, selecting your virtual CD drive, and browsing to the ISO file on your computer.

    Boot (or restart) your virtual machine after inserting the ISO image and the virtual machine will boot from the ISO image. GParted’s live CD will ask you several questions while booting – you can press Enter to skip them for the default options.

    Once GParted is booted, right-click the partition you want to enlarge and select Resize/Move.

    Specify a new size for the partition – for example, drag the slider all the way to the right to use all the available space for the partition. Click the Resize/Move button after you’ve specified the space you want to use.

    Finally, click the Apply button to apply your changes and enlarge the partition.

    After the resize operation completes, restart your virtual machine and remove the GParted ISO file. Windows will check the file system in your virtual machine to ensure it’s working properly — don’t interrupt this check.

    The virtual machine’s partition will now take up the entire virtual hard disk, so you’ll have access to the additional space.