NAME
Net::DNSBL::Client - Client code for querying multiple DNSBLs
SYNOPSIS
use Net::DNSBL::Client;
my $c = Net::DNSBL::Client->new({ timeout => 3 });
$c->query_ip('127.0.0.2', [
{ domain => 'simple.dnsbl.tld' },
{ domain => 'masked.dnsbl.tld', type => 'mask', data => '0.0.0.255' },
{ domain => 'txt.dnsbl.tld', type => 'txt' },
{ domain => 'need-a-key.example.net' }],
{ lookup_keys => { 'need-a-key.example.net' => 'my_secret_key' }});
# And later...
my $answers = $c->get_answers();
METHODS
Class Methods
- new ( $args )
-
Returns a new Net::DNSBL::Client object.
$args is a hash reference and may contain the following key-value pairs:
- resolver
-
(optional) A Net::DNS::Resolver object. If not provided, a new resolver will be created.
- timeout
-
(optional) An integer number of seconds to use as the upper time limit for the query. If not provided, the default is 10 seconds. If provided, timeout must be a positive integer.
Instance Methods
- get_resolver ( )
-
Returns the Net::DNS::Resolver object used for DNS queries.
- get_timeout ( )
-
Returns the timeout in seconds for queries.
- set_timeout ( $secs )
-
Sets the timeout in seconds for queries.
- query_is_in_flight ( )
-
Returns non-zero if "query" has been called, but "get_answers" has not yet been called. Returns zero otherwise.
- query_ip ( $ipaddr, $dnsbls [, $options])
-
Issues a set of DNS queries. Note that the query_ip() method returns as soon as the DNS queries have been issued. It does not wait for DNS responses to come in. Once query_ip() has been called, the Net::DNSBL::Client object is said to have a query in flight. query_ip() may not be called again while a query is in flight.
$ipaddr is the text representation of an IPv4 or IPv6 address.
$dnsbls is a reference to a list of DNSBL entries; each DNSBL entry is a hash with the following members:
- domain
-
(required) The domain to query. For example, zen.spamhaus.org.
- type
-
(optional) The type of DNSBL. Possible values are normal, meaning that any returned A record indicates a hit, match, meaning that one of the returned A records must exactly match a given IP address, mask, meaning that one of the returned A records must evaluate to non-zero when bitwise-ANDed against a given IP address, or txt meaning that TXT records should be looked up and returned (rather than A records)a. If omitted, type defaults to normal
- data
-
(optional) For the match and mask types, this data specifies the required match or the bitwise-AND mask. In the case of a mask type, the data can be something like "0.0.0.4", or an integer like "8". In the latter case, the integer n must range from 1 to 255 and is equivalent to 0.0.0.n.
- userdata
-
(optional) This element can be any scalar or reference that you like. It is simply returned back unchanged in the list of hits.
$options, if supplied, is a hash of options. Currently, three options are defined:
- early_exit
-
If set to 1, querying will stop after the first positive result is received, even if other DNSBLs are being queried. Default is 0.
- return_all
-
If set to 1, then the return value from get_answers() will contain all DNSBLs that were supplied to query_ip(), even if the DNSBL did not hit. If set to 0 (the default), then the return value from get_answers() only returns entries for those DNSBLs that actually hit.
- lookup_keys
-
This is a hashref of domain_name => key. Some domains require a secret key to be inserted just before the domain name; rather than including the key in the domain, you can separate it out with the lookup_keys hash, making the returned results more readable.
- query_domain ( $domain, $dnsbls [, $options])
-
Similar to query_ip, but considers $domain to be a domain name rather than an IP address, and does not reverse the domain.
- get_answers ( )
-
This method may only be called while a query is in flight. It waits for DNS replies to come back and returns a reference to a list of hits. Once get_answers() returns, a query is no longer in flight.
Note that the list of hits is not necessarily returned in the same order as the original list of DNSBLs supplied to query_ip().
Each hit in the returned list is a hash reference containing the following elements:
- domain
-
The domain of the DNSBL.
- hit
-
Set to 1 if the DNSBL was hit or 0 if it was not. (You will only get entries with hit set to 0 if you used the return_all option to query_ip().)
- type
-
The type of the DNSBL (normal, match or mask).
- data
-
The data supplied (for normal and mask types)
- userdata
-
The userdata as supplied in the query_ip() call
- actual_hits
-
Reference to array containing actual A or TXT records returned by the lookup that caused a hit.
- replycode
-
The reply code from the DNS server (as a string). Likely to be one of NOERROR, NXDOMAIN, SERVFAIL or TIMEOUT. (TIMEOUT is not a real DNS reply code; it is synthesized by this Perl module if the lookup times out.)
The hit may contain other elements not documented here; you should count on only the elements documented above.
If no DNSBLs were hit, then a reference to a zero-element list is returned.
DEPENDENCIES
Net::DNS::Resolver, IO::Select
AUTHOR
David Skoll <dfs@roaringpenguin.com>, Dave O'Neill <dmo@roaringpenguin.com>
COPYRIGHT AND LICENSE
Copyright (c) 2010 Roaring Penguin Software
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.