Marc Lehmann

NAME

EV::ADNS - lightweight asynchronous dns queries using EV and libadns

SYNOPSIS

 use EV;
 use EV::ADNS;

 EV::ADNS::submit "example.com", EV::ADNS::r_addr, 0, sub {
    my ($status, $expires, @a) = @_;
    warn $a[0]; # "127.13.166.3" etc.
 };

 EV::loop;

DESCRIPTION

This is a simple interface to libadns (asynchronous dns) that integrates well and automatically into the EV event loop. The documentation for libadns is vital to understand this module, see http://www.chiark.greenend.org.uk/~ian/adns/.

You can use it only with EV (directly or indirectly, e.g. via Glib::EV). Apart from loading and using the submit function you need not do anything (except run an EV event loop).

OVERVIEW

All the constants/enums from adns.h are available in the EV::ADNS namespace, without the adns_ prefix, e.g. adns_r_a becomes EV::ADNS::r_a, adns__qtf_deref becomes EV::ADNS::_qtf_deref and so on.

FUNCTIONS

$query = EV::ADNS::submit "domain", $rrtype, $flags, $cb

Submits a new request to be handled. See the adns_submit C function description for more details. The function optionally returns a query object which can be used to cancel an in-progress request. You do not need to store the query object, even if you ignore it the query will proceed.

The callback will be invoked with a result status, the time the resource record validity expires and zero or more resource records, one scalar per result record. Example:

   sub adns_cb {
      my ($status, $expires, @rr) = @_;
      if ($status == EV::ADNS::s_ok) {
         use JSON::XS;
         warn encode_json \@rr;
      }
   }

The format of result records varies considerably, here is some cursory documentation of how each record will look like, depending on the query type:

EV::ADNS::r_a, EV::ADNS::r_addr

An IPv4 address in dotted quad (string) form.

EV::ADNS::r_ns_raw, EV::ADNS::r_cname, EV::ADNS::r_ptr, EV::ADNS::r_ptr_raw

The resource record as a simple string.

EV::ADNS::r_txt

An arrayref of strings.

EV::ADNS::r_ns

A "host address", a hostname with any number of addresses (hint records).

Currently only the hostname will be stored, so this is alway an arrayref with a single element of the hostname. Future versions might add additional address entries.

EV::ADNS::r_hinfo

An arrayref consisting of the two strings.

EV::ADNS::r_rp, EV::ADNS::r_rp_raw

An arrayref with two strings.

EV::ADNS::r_mx

An arrayref consisting of the priority and a "host address" (see EV::ADNS::r_ns). Example:

   [10, "mail10.example.com"]
EV::ADNS::r_mx_raw

An arrayref consisting of the priority and the hostname, e.g. [10, "mail.example.com"].

EV::ADNS::r_soa, EV::ADNS::r_soa_raw

An arrayref consisting of the primary nameserver, admin name, serial, refresh, retry expire and minimum times, e.g.:

  ["ns.example.net", "hostmaster@example.net", 2000001102, 86400, 21600, 2592000, 172800]

The "raw" form doesn't mangle the e-mail address.

EV::ADNS::r_srv_raw

An arrayref consisting of the priority, weight, port and hostname, e.g.:

   [10, 10, 5060, "sip1.example.net"]
EV::ADNS::r_srv

The same as EV::ADNS::r_srv_raw, but the hostname is replaced by a "host address" (see EV::ADNS::r_ns).

EV::ADNS::r_unknown

A single octet string with the raw contents.

anything else

Currently undef.

$query->cancel

Cancels a request that is in progress.

SEE ALSO

EV, Net::ADNS another interface to adns, maybe better, but without real support to integrate it into other event loops.

AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/



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