NAME

statefulProtect - Parametric script used for monitor stateful's event

SYNOPSIS

statefulProtect EVT_NAME RANGE EVT_BOUND RED_BOUND FREQ_EMAIL ALLOWED_FILE NOTIFY FILTER EVT_LIST

DESCRIPTION

Used for specifies rule with kind STATEFUL_FILTER specified in configuration's file /etc/aLid/aLid.conf. Packet's detection happen through packet's analysis (described in log's file). It allows to intercept events identified by more patterns in sequence:

Es. Three way handshake. TCP protocol at beginning of comunication between two hosts want a particular packet's exchange:

        PC1 --- SYN --> PC2
        PC1 <-- SYN ACK -- PC2
        PC1 --- ACK --> PC2

If you want describe a filter that intercept this event you needs to define regular expression's list and a target's list. Responsible ip, in this case, is host that begin comunication; in first and third packet it is the source ip(), while in the second packet it is the destination ip(O).

        EXPRESSION=RES=\w+\sSYN\sURGP            TARGET=I
        EXPRESSION=RES=\w+\sACK\sSYN\sURGP       TARGET=O
        EXPRESSION=RES=\w+\sACK\sURGP            TARGET=I

OPTIONS

EVT_NAME

It specifics the event's name in which is associated a rule. The name of event allows to indenfy the rule, that send a notific or drop's rule. The name of event is unambiguous in all rules.

RANGE

It is the value, in seconds, of the temporal window to analyze. If N is the value of range, the temporal window to analyze is [ NOW - N , NOW ].

EVT_BOUND

It's the maximun number of times that the found event can verifies inside of temporal window(RANGE). Source ip, findable on log file, is considered responsible. At the overcoming of threshold, depending on configuration, can block source ip or simply notify what is happened. If an ip is blocked, there is also a mark of the moment in which it happens with reference to universal time (UTC) in seconds.

RED_BOUND

It is the number of seconds in which an blocked ip can't communicate through machine where is installed the program. When the redemption's source is reached blocked ip is unlocked. The overcoming is calculated in the following way:

        IF ( NOW - BLOCKING_TIME > RED_BOUNG ) 
                UNLOCK BLOCKED IP 
        ELSE
                BLOCKED IP REMAINS BLOCKED

FREQ_EMAIL

It specifics the attendance of send of notifics mail in seconds. It's optional and subordinate at the presence of options MAIL or LOG.

ALLOWED_FILE

It is file's path where are listed allowed ip. If is detected an event with ip present in ALLOWED_FILE so event is ignored. File must respect following syntattic rule: every rule must contains only an ip.

NOTIFY There are 4 kinds of notific option: MAIL, LOG, ALL, NOTHING.

MAIL

It sends a notific email to alla addresses specified on file /etc/aLid/email.conf

LOG

It allows to write a line on log file of application.

ALL

Include both notify's typologies MAIL e LOG.

NOTHING

No nothification

FILTER

It specifics the policy to adopt considering ip detected. Options accepted are: DROP and NODROP.

DROP

It blocks detected ip in the firewall applying a specific rule.

NODROP

It doesn't execute a rule of drop in the firewall.

EVT_LIST

List of monitored events that made up a stateful filter. Must respect following syntax:

EXPR_REG_1 TARGET_1 EXPR_REG_2 TARGET_2 ... EXPR_REG_N TARGET_N

EXPR_REG

It is a filter's sub-evento. Sub-events must match in sequence.

TARGET

Describes the position, in log's line, of responsible's host of event.

NOTES

Script reads of input file indicated in the rule through stream <STDIN>.

EXAMPLES

Configuration's example:

statefulProtect THREE_WAY_HANDSHAKE 10 5 7 7 /etc/aLid/ip_allowed_THREE_WAY_HANDSHAKE log drop FILE_INPUT=/var/log/iptables.log

EXPRESSION=RES=\w+\sSYN\sURGP TARGET=I EXPRESSION=RES=\w+\sACK\sSYN\sURGP TARGET=O EXPRESSION=RES=\w+\sACK\sURGP TARGET=I

It executes script with THREE_WAY_HANDSHAKE as event name, using a range of 10 seconds, 5 maximum attempts in temporal window, 7 seconds as redemption threshold, 7 seconds is mail's frequency, ip_allowed_THREE_WAY_HANDSHAKE is the name of file used to specified immunes ip at event, all is notific's typology and drop is the kind of filter. FILE_INPUT is a log's file.

FILES

/etc/aLid/aLid.conf

Configuration's file of the application.

REQUIREMENT

DateTime

DateTime - Perl Library of cpan community

SEE ALSO

sharedTail, aLid, aLid.conf

AUTHOR

Andrea Martire (andreamartire@gmail.com)

COPYRIGHT AND LICENSE

Copyright © 2010 Andrea Martire <andreamartire@gmail.com>. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.