Mail::SpamAssassin::PlUser:Contributed Perl Mail::SpamAssassin::Plugin::ASN(3)
NAME
Mail::SpamAssassin::Plugin::ASN - SpamAssassin plugin to look up the
Autonomous System Number (ASN) of the connecting IP address.
SYNOPSIS
loadplugin Mail::SpamAssassin::Plugin::ASN
asn_lookup asn.routeviews.org _ASN_ _ASNCIDR_
asn_lookup_ipv6 origin6.asn.cymru.com _ASN_ _ASNCIDR_
add_header all ASN _ASN_ _ASNCIDR_
header TEST_AS1234 X-ASN =~ /^1234$/
DESCRIPTION
This plugin uses DNS lookups to the services of an external DNS zone
such as at "http://www.routeviews.org/" to do the actual work. Please
make sure that your use of the plugin does not overload their
infrastructure - this generally means that you should not use this
plugin in a high-volume environment or that you should use a local
mirror of the zone (see "ftp://ftp.routeviews.org/dnszones/"). Other
similar zones may also be used.
TEMPLATE TAGS
This plugin allows you to create template tags containing the
connecting IP's AS number and route info for that AS number.
The default config will add a header field that looks like this:
X-Spam-ASN: AS24940 213.239.192.0/18
where "24940" is the ASN and "213.239.192.0/18" is the route announced
by that ASN where the connecting IP address came from. If the AS
announces multiple networks (more/less specific), they will all be
added to the "_ASNCIDR_" tag, separated by spaces, eg:
X-Spam-ASN: AS1680 89.138.0.0/15 89.139.0.0/16
Note that the literal "AS" before the ASN in the _ASN_ tag is
configurable through the asn_prefix directive and may be set to an
empty string.
CONFIGURATION
The standard ruleset contains a configuration that will add a header
field containing ASN data to scanned messages. The bayes tokenizer
will use the added header field for bayes calculations, and thus affect
which BAYES_* rule will trigger for a particular message.
Note that in most cases you should not score on the ASN data directly.
Bayes learning will probably trigger on the _ASNCIDR_ tag, but probably
not very well on the _ASN_ tag alone.
SEE ALSO
http://www.routeviews.org/ - all data regarding routing, ASNs, etc....
http://issues.apache.org/SpamAssassin/show_bug.cgi?id=4770 -
SpamAssassin Issue #4770 concerning this plugin
STATUS
No in-depth analysis of the usefulness of bayes tokenization of ASN
data has been performed.
ADMINISTRATOR SETTINGS
asn_lookup asn-zone.example.com [ _ASNTAG_ _ASNCIDRTAG_ ]
Use this to lookup the ASN info in the specified zone for the first
external IPv4 address and add the AS number to the first specified
tag and routing info to the second specified tag.
If no tags are specified the AS number will be added to the _ASN_
tag and the routing info will be added to the _ASNCIDR_ tag. You
must specify either none or both of the tag names. Tag names must
start and end with an underscore.
If two or more asn_lookups use the same set of template tags, the
results of their lookups will be appended to each other in the
template tag values in no particular order. Duplicate results will
be omitted when combining results. In a similar fashion, you can
also use the same template tag for both the AS number tag and the
routing info tag.
Examples:
asn_lookup asn.routeviews.org
asn_lookup asn.routeviews.org _ASN_ _ASNCIDR_
asn_lookup myview.example.com _MYASN_ _MYASNCIDR_
asn_lookup asn.routeviews.org _COMBINEDASN_ _COMBINEDASNCIDR_
asn_lookup myview.example.com _COMBINEDASN_ _COMBINEDASNCIDR_
asn_lookup in1tag.example.net _ASNDATA_ _ASNDATA_
asn_lookup_ipv6 asn-zone6.example.com [_ASN_ _ASNCIDR_]
Use specified zone for lookups of IPv6 addresses. If zone supports
both IPv4 and IPv6 queries, use both asn_lookup and asn_lookup_ipv6
for the same zone.
clear_asn_lookups
Removes any previously declared asn_lookup entries from a list of
queries.
asn_prefix 'prefix_string' (default: 'AS')
The string specified in the argument is prepended to each ASN when
storing it as a tag. This prefix is rather redundant, but its
default value 'AS' is kept for backward compatibility with versions
of SpamAssassin earlier than 3.4.0. A sensible setting is an empty
string. The argument may be (but need not be) enclosed in single or
double quotes for clarity.
perl v5.26.3 2021-04-09Mail::SpamAssassin::Plugin::ASN(3)