Linux Certif

Toute la documentation sur la certification Linux LPI

iplog.conf

NAME

iplog.conf - iplog configuration file.

DESCRIPTION

Upon execution and upon being restarted, iplog reads a list of configuration rules from its configuration file. The default location of this file is /etc/iplog.conf.

NOTATION

Throughout this document, required parameters will be denoted by enclosing the parameter in angle brackets <like this>.

Optional parameters will be denoted by enclosing the parameter in square brackets [like this].

The '|' character is used to express exclusive or. For example [true|false] means you may give "true" or "false", but not both.

COMMENTS

The '#' character marks the beginning of a comment. C-style (/**/) comments are accepted, also.

RULE CLASSES

There are nine classes of rules supported in the iplog configuration file. These rules are: set rules, interface rule, priority rule, facility rule, user rule, group rule, promisc rule, logfile rule, and pid-file rule.

SET RULE SYNTAX

Set rules allow for boolean program options to be enabled or disabled at runtime.

The syntax for "set" rules is:
set <keyword> [true|false]

SET KEYWORDS

tcp

Log or ignore TCP traffic.

udp

Log or ignore UDP traffic.

icmp

Log or ignore ICMP traffic.

frag

Enable or disable detection of IP fragment attacks (duplicated and overlapping fragments).

smurf

Enable or disable detection of "smurf" attacks.

bogus

Enable or disable detection of TCP packets with invalid TCP flags set. Programs such as nmap and queso may set these flags while trying to perform OS detection.

log_ip

Enable or disable logging IP addresses in addition to host names.

log_dest

Log the destination address of IP packets that are received.

stdout

Enable or disable logging to stdout. This option is incompatible with the "logfile" keyword.

no_fork

Enable or disable running in the foreground.

verbose

Enable or disable verbose mode. In verbose mode, packets with invalid checksums and truncated headers are logged.

fin_scan

Enable or disable the detection of TCP FIN scans.

syn_scan

Enable or disable the detection of TCP SYN scans.

udp_scan

Enable or disable the detection of UDP scans and UDP floods.

portscan

Enable or disable the detection of TCP port scans.

fool_nmap

Enable or disable a mechanism that attempts to fool programs, such as nmap and queso, that perform remote OS detection. As a side effect, enabling this option will also cause most of nmap's "stealth" scans to fail.

xmas_scan

Enable or disable the detection of TCP XMas scans.

null_scan

Enable or disable the detection of TCP null scans.

get_ident

Enable or disable fetching IDENT info for connections to local ports that are listening. This option is only available on Linux.

dns_cache

Enable or disable the use of a built-in DNS cache.

syn_flood

If this option is enabled, iplog will stop resolving IP addresses (until the flood ends) if a SYN flood is detected.

ignore_dns

If this option is enabled, DNS traffic from hosts listed in /etc/resolv.conf will be ignored.

ping_flood

Enable or disable detection of ICMP ping floods.

scans_only

Enable or disable detecting only scans and floods.

traceroute

Enable or disable detection of traceroute.

udp_resolve

Enable or disable looking up the host names for the source and destination hosts for UDP traffic.

tcp_resolve

Enable or disable looking up the host names for the source and destination hosts for TCP traffic.

icmp_resolve

Enable or disable looking up the host names for the source and destination hosts for ICMP traffic.

disable_resolver

Enable or disable turning off host name lookups for all traffic.

INTERFACE RULE SYNTAX

The interface rule is used to define the interfaces on which iplog will listen.

The rule format for the interface rule is:
interface <if0,...,ifN>
Where ifX is an interface name.

PRIORITY RULE SYNTAX

The priority rule is used to define the syslog(3) priority (or level) that iplog will use.

The rule format for the priority rule is:
priority <syslog_priority>
See the syslog(3) for a list of valid priority levels.

FACILITY RULE SYNTAX

The facility rule is used to define the syslog(3) facility that iplog will use.

The rule format for the facility rule is:
facility <syslog_facility>
See the syslog(3) for a list of valid syslog facilities.

USER RULE SYNTAX

The user rule is used to define which user iplog will run as.

The user rule format is:
user <UID|username>

GROUP RULE SYNTAX

The group rule is used to define which group iplog will run with.

The group rule format is:
group <GID|group>

LOGFILE RULE SYNTAX

The logfile rule is used to define a file to which iplog will log its output. iplog can either log to syslog, to stdout or to a logfile, but only one.

The logfile rule format is:
logfile <path_to_logfile>

PID-FILE RULE SYNTAX

The pid-file rule is used to specify the location of iplog's pid file. The user that iplog will run as should have write access to the directory the specified file is in. The location of the pid file defaults to /var/run/iplog.pid.

This option should be used when iplog is set to run as a user that does not have write access to /var/run.

The pid-file rule format is:
pid-file <path_to_pid-file>

PROMISC RULE SYNTAX

The promisc rule enables iplog to operate in promiscuous mode. In promiscuous mode, iplog examines traffic to all visible hosts on the local network.

The rule format for the promisc rule is:
promisc <network0,...,networkN>

FILTER RULE SYNTAX

The rule format for TCP and UDP filters is:
<log|ignore> <tcp|udp>
from [!]<address>[/<mask>]]
[sport [!]<port-start[:[<port-end>]]]
[to [!]<address>[/<mask>]]
[dport [!]<port-start[:[<port-end>]]>]
(All on one line)

The rule format for ICMP filters is:
<log|ignore> icmp
[type [!]<type>]
[from [!]<address>[/<mask>]]
[to [!]<address>[/<mask>]]
(All on one line)

FILTER KEYWORDS

The sense of a keyword can be inverted by prefixing its argument with a '!' character.

log

Log packets matching the rule. Either this or ignore must be the first keyword specified in a rule. The log and ignore keywords cannot be used in the same rule.

ignore

Ignore packets matching the rule. Either this or log must be the first keyword specified in a rule. The log and ignore keywords cannot be used in the same rule.

tcp

Specifies this rule should be applied to TCP traffic. Exactly one of the tcp, udp and icmp keywords must be used in each rule.

udp

Specifies this rule should be applied to UDP traffic. Exactly one of the tcp, udp and icmp keywords must be used in each rule.

icmp

Specifies this rule should be applied to ICMP traffic. Exactly one of the tcp, udp and icmp keywords must be used in each rule.

from <Address parameter>

The from keyword specifies the source address(es) the rule will match.

to <Address parameter>

The to keyword specifies the destination address(es) the rule will match.

sport <Port parameter>

The sport keyword specifies the source port(s) the rule will match. This keyword is applicable only to TCP and UDP rules.

dport <Port parameter>

The dport keyword specifies the destination port(s) the rule will match. This keyword is applicable only to TCP and UDP rules.

type <Type parameter>

The type keyword specifies an ICMP type. This keyword is applicable only to ICMP rules.

FILTER PARAMETER SYNTAX

An asterisk character ('*') may be used as a wildcard for any parameter.

Address parameters

The syntax for an address parameter is [!]<addr>[/<mask>] The addr token specifies the address the rule will match. This token may be specified in quad-dot notation or as a fully qualified domain name (FQDN). The mask token is optional, and is used to specify a range of addresses the rule will match. The mask token may be specified either in quad-dot notation, as a FQDN or in CIDR notation. If the mask token is present, the addr token will be treated as a network address.

Port parameters

The syntax for a port parameter is [!]<port-start[:[<port-end>]]> The port-start token specifies the port the rule will match. This token may be specified as either a decimal number or as a service name (e.g. "telnet"). The optional port-end token is used to define port ranges the rule will match. The port-end token also may be specified as either a decimal number or a service name. When the port-end token is present, the port-start token is interpreted as the first port the rule will match. Suffixing port-start with a ':' but omitting the port-end parameter causes port-end to be implicitly set to 65535 (i.e. all ports greater than or equal to port-start will be matched). In general, "port1:portN" will match all ports from port1 to portN, inclusive. "port1:" matches all ports from port1 to 65535, inclusive.

Type parameters

Either integers or a string can be used to specify a type parameter. Obviously, only an integer can be used to describe a type that has no name. "ICMP_" may precede any of the names. Legal type parameters follow:

 
 
 NAME                          CODE
 ECHOREPLY                     0
 n/a                           1
 n/a                           2
 UNREACH                       3
 SOURCEQUENCH                  4
 REDIRECT                      5
 n/a                           6
 n/a                           7
 ECHO                          8
 ROUTERADVERT                  9
 ROUTERSOLICIT                 10
 TIMXCEED                      11
 PARAMPROB                     12
 TSTAMP                        13
 TSTAMPREPLY                   14
 IREQ                          15
 IREQREPLY                     16
 MASKREQ                       17
 MASKREPLY                     18
 
 

GENERAL FILTER SYNTAX

*

Case is ignored in all places, except for in a service name (i.e. "telnet").

*

All parameters are optional except "log" or "ignore" and "tcp" "udp" and "icmp". Either log or ignore must be specified for each rule. Exactly one of the "tcp" "udp" and "icmp" parameters must be specified for each rule.

*

The order in which the rules are listed is not significant in regard to "log" or "ignore." The entries will be reordered such that all "log" statements precede all "ignore" statements.

EXAMPLES

Run as user nobody.
user nobody

Run with group nogroup.
group nogroup

Log to /var/log/iplog
logfile /var/log/iplog

Use the syslog(3) facility log_daemon.
facility log_daemon

Use the syslog(3) priority (level) log_info.
priority log_info

Log the IP address as well as the hostname of packets.
set log_ip true

Do not log the destination of packets.
set log_dest false

Ignore DNS traffic from nameservers in /etc/resolv.conf.
set ignore_dns

Listen on eth0 and eth1
interface eth0,eth1

Ignore DNS traffic from nameservers.
ignore udp from 192.168.0.1 sport 53
ignore udp from 192.168.0.2 sport 53
NOTE: (Using the -d option will add similar rules for all nameservers listed in /etc/resolv.conf).

Log connections with source port ftp-data (20) to ports 1045-1055, inclusive.
log tcp dport 1045:1055 sport ftp-data

Ignore ftp-data connections from to ports 1024 and above.
ignore tcp dport 1024: sport 20

Ignore WWW connections.
ignore tcp dport 80

Ignore ICMP unreach.
ignore icmp type unreach
or
ignore icmp type 3

Ignore ICMP traffic with any type other than ECHO
ignore icmp type !echo

Ignore UDP traffic from the 127.1.2 network
ignore udp from 127.1.2/24
or
ignore udp from 127.1.2/255.255.255.0

AUTHOR

Ryan McCabe <odin@numb.org>

SEE ALSO

iplog(8) syslog(3) services(5)