Mail::SpamAssassin::DnsResolver(3)
NAME
Mail::SpamAssassin::DnsResolver - DNS resolution engine
DESCRIPTION
This is a DNS resolution engine for SpamAssassin, implemented in order
to reduce file descriptor usage by Net::DNS and avoid a response
collision bug in that module.
METHODS
$res->load_resolver()
Load the "Net::DNS::Resolver" object. Returns 0 if Net::DNS cannot
be used, 1 if it is available.
$resolver = $res->get_resolver()
Return the "Net::DNS::Resolver" object.
$res->nameservers()
Wrapper for Net::DNS::Resolver->nameservers to get or set list of
nameservers
$res->connect_sock()
Re-connect to the first nameserver listed in "/etc/resolv.conf" or
similar platform-dependent source, as provided by "Net::DNS".
$res->get_sock()
Return the "IO::Socket::INET" object used to communicate with the
nameserver.
$packet = new_dns_packet ($host, $type, $class)
A wrapper for "Net::DNS::Packet::new()" which traps a die thrown by
it.
To use this, change calls to "Net::DNS::Resolver::bgsend" from:
$res->bgsend($hostname, $type);
to:
$res->bgsend(Mail::SpamAssassin::DnsResolver::new_dns_packet($hostname, $type, $class));
$id = $res->bgsend($host, $type, $class, $cb)
Quite similar to "Net::DNS::Resolver::bgsend", except that when a
response packet eventually arrives, and "poll_responses" is called,
the callback sub reference $cb will be called.
Note that $type and $class may be "undef", in which case they will
default to "A" and "IN", respectively.
The callback sub will be called with two arguments -- the packet
that was delivered and an id string that fingerprints the query
packet and the expected reply. It is expected that a closure
callback be used, like so:
my $id = $self->{resolver}->bgsend($host, $type, undef, sub {
my $reply = shift;
my $reply_id = shift;
$self->got_a_reply ($reply, $reply_id);
});
The callback can ignore the reply as an invalid packet sent to the
listening port if the reply id does not match the return value from
bgsend.
$nfound = $res->poll_responses()
See if there are any "bgsend" response packets ready, and return
the number of such packets delivered to their callbacks.
$res->bgabort()
Call this to release pending requests from memory, when aborting
backgrounded requests, or when the scan is complete.
"Mail::SpamAssassin::PerMsgStatus::check" calls this before
returning.
$packet = $res->send($name, $type, $class)
Emulates "Net::DNS::Resolver::send()".
$res->errorstring()
Little more than a stub for callers expecting this from
"Net::DNS::Resolver".
If called immediately after a call to $res->send this will return
"query timed out" if the $res->send DNS query timed out. Otherwise
"unknown error or no error" will be returned.
No other errors are reported.
$res->finish_socket()
Reset socket when done with it.
$res->finish()
Clean up for destruction.
perl v5.10.0 2007-06-19Mail::SpamAssassin::DnsResolver(3)
Mac OS X 10.6Server - Generated Thu Apr 15 06:47:04 CDT 2010