Postfix Changing Outgoing IP By Time Interval Using TCP_TABLE And Perl

Someone asked me if i can make a perl scripts that can change the ip address based on time interval, say he want ip address 1.2.3.4 used within one hour, if done next ip address will be used within next one hour..and so on. when it came to highest number of ip address in array, they will be reset back to the start. first i suggest him to look at the articles i wrote. But then i decide to write Perl script which was made for the purposes mention above.

here we are..

Postfix section:

master.cf
127.0.0.1:2527 inet  n       n       n       -       0      spawn
          user=nobody argv=/etc/postfix/ip_by_time.pl

ip1  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip1
          -o smtp_helo_name=smtp1.example.com
          -o smtp_bind_address=1.2.3.1

ip2  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip2
          -o smtp_helo_name=smtp2.example.com
          -o smtp_bind_address=1.2.3.2

ip3  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip3
          -o smtp_helo_name=smtp3.example.com
          -o smtp_bind_address=1.2.3.3

ip4  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip4
          -o smtp_helo_name=smtp4.example.com
          -o smtp_bind_address=1.2.3.4
....
....

main.cf

transport_maps = tcp:[127.0.0.1]:2527
127.0.0.1:2527_time_limit = 3600s

Perl section:

#!/usr/bin/perl
use strict;
use warnings;
use Storable;

## interval between ip switchover, one hour for example
my $ip_interval=3600;

my $hashfile="data.hash";
store {}, $hashfile unless -r $hashfile;

my @smtp_array = (
'ip1:',
'ip2:',
'ip3:',
'ip4:',
'ip5:',
'ip6:',
'ip7:',
'ip8:',
'ip9:',
'ip:'
);
# and more ips

#
# Autoflush standard output.
#
select STDOUT; $|++;

while (<>) {
        chomp;
        my $time_stamp = retrieve($hashfile);
        my $now = time();

        if (!defined $time_stamp->{'time_diff'}) {
                $time_stamp->{'time_diff'} = $now;
                $time_stamp->{'ip_index'} = 0;
                store $time_stamp, $hashfile;
        }

        if (/^get\s(.+)$/i) {
                if ($now > $time_stamp->{'time_diff'} + $ip_interval) {
                        if ($time_stamp->{'ip_index'} < scalar(@smtp_array) - 1) {
                                $time_stamp->{'ip_index'}++;
                        } else {
                                $time_stamp->{'ip_index'} = 0;
                        }
                        print "200 $smtp_array[$time_stamp->{'ip_index'}]\n";
                        $time_stamp->{'time_diff'} = $now;
                        store $time_stamp, $hashfile;
                        next;
                } else {
                        print "200 $smtp_array[$time_stamp->{'ip_index'}]\n";
                        next;
                }
        }

        ## default response
        print "200 smtp:\n";
}

Good luck.
PS: not tested in real environtment

You may also want to read these posts:

• Postfix Randomizing Outgoing IP Using TCP_TABLE And Perl
• Postfix Bind Sender Outgoing IP, Based On GeoIP Location
• Postfix Bind Sender Domain To Dedicated Outgoing IP Address
• Postfix Rotating Outgoing IP Using TCP_TABLE And Perl
• Measure Response Time Of SMTP Connections Using Perl
• postfix, integrating memcache as a lookup table using tcp_table
• Postfix Create Blackhole For Authenticated User’s Outgoing Submission (revised)
• Postfix, Maildir Replication In Real Time Using ChironFS
• Geo Location DNSBL Using Perl, Memcached And GeoIP
• Postfix GeoIP Based Rejections