package Net::Bonjour::Entry; =head1 NAME Net::Bonjour::Entry - Support module for mDNS service discovery (Apple's Bonjour) =head1 SYNOPSIS use Net::Bonjour; my $res = Net::Bonjour->new([, ]); $res->discover; foreach my $entry ( $res->entries ) { print $entry->name, "\n"; } =head1 DESCRIPTION Net::Bonjour::Entry is a module used to manage entries returned by a mDNS service discovery (Apple's Bonjour). See L for more information. =head1 METHODS =head2 new([]) Creates a new Net::Bonjour::Entry object. The optional argument defines the fully qualifed domain name (FQDN) of the entry. Normal usage of the L module will not require the construction of Net::Bonjour::Entry objects, as they are automatically created during the discovery process. =head2 address Returns the IP address of the entry. =head2 all_attrs Returns all the current attributes in the form of hashed array. =head2 attribute() Returns the specified attribute from the TXT record of the entry. TXT records are used to specify additional information, e.g. path for http. =head2 dnsrr([]) Returns an DNS answer packet of the entry. The output will be in the format of a L object. The I designates the resource record to answer with, i.e. PTR, SRV, or TXT. The default is PTR. =head2 fetch Reloads the information for the entry via mDNS. =head2 fqdn Returns the fully qualifed domain name (FQDN) of entry. An example FQDN is server._afpovertcp._tcp.local =head2 hostname Returns the hostname of the server, e.g. 'server.local'. =head2 name Returns the name of the entry. In the case of the fqdn example, the name would be 'server'. This name may not be the hostname of the server. For example, names for presence/tcp will be the name of the user and http/tcp will be title of the web resource. =head2 port Returns the TCP or UDP port of the entry. =head2 sockaddr Returns the binary socket address for the resource and can be used directly to bind() sockets. =head1 EXAMPLES =head2 Print out a list of local websites print "Local Websites"; use Net::Bonjour; my $res = Net::Bonjour->new('http'); $res->discover; foreach my $entry ( $res->entries) { printf "%s
", $entry->address, $entry->attribute('path'), $entry->name; } print ""; =head2 Find a service and connect to it use Net::Bonjour; my $res = Net::Bonjour->new('custom'); $res->discover; my $entry = $res->shift_entry; socket SOCK, PF_INET, SOCK_STREAM, scalar(getprotobyname('tcp')); connect SOCK, $entry->sockaddr; print SOCK "Send a message to the service"; while ($line = ) { print $line; } close SOCK; =head1 SEE ALSO L =head1 COPYRIGHT This library is free software and can be distributed or modified under the same terms as Perl itself. Bonjour (in this context) is a trademark of Apple Computer, Inc. =head1 AUTHORS The Net::Bonjour::Entry module was created by George Chlipala =cut use strict; use warnings; use vars qw($AUTOLOAD); use Socket; use Net::DNS; sub new { my $self = {}; bless $self, shift; $self->_init(@_); return $self; } sub _init { my $self = shift; $self->{'_dns_server'} = [ '224.0.0.251' ]; $self->{'_dns_port'} = '5353'; $self->{'_ip_type'} = 'A'; $self->{'_index'} = 0; $self->{'_ttl'} = 3600; if ( ref($_[0]) eq 'HASH') { my $attrs = shift; foreach my $k ( keys(%{$attrs}) ) { $self->{'_' . $k} = $attrs->{$k}; } $self->all_attrs if ref( $attrs->{'attr'} ) eq 'HASH'; } elsif ( $#_ == 0 ) { $self->fqdn(shift); } return; } sub fetch { my $self = shift; my $res = Net::DNS::Resolver->new( nameservers => $self->{'_dns_server'}, port => $self->{'_dns_port'} ); # Hey, I get to cite an RFC: # # DNS-SD draft, section 6.1 # Note that when using Multicast DNS [mDNS] the maximum packet size is # 9000 bytes, including IP header, UDP header, and DNS message header, # which imposes an upper limit on the size of TXT records of about 8900 # bytes. In practice the maximum sensible size of a DNS-SD TXT record # size is smaller even than this, typically at most a few hundred # bytes, as described below in Section 6.2. $res->udppacketsize( 9000 ); my ($name, $protocol, $ipType) = split(/(?fqdn,3); $self->{'_name'} = $name; $self->type($protocol, $ipType); my $srv = $res->query($self->fqdn(), 'SRV') || return; my $srvrr = ($srv->answer)[0]; $self->priority($srvrr->priority); $self->weight($srvrr->weight); $self->port($srvrr->port); $self->hostname($srvrr->target); if ($srv->additional) { foreach my $additional ($srv->additional) { $self->{'_' . uc($additional->type)} = $additional->address; } } else { my $aquery = $res->query($srvrr->target, 'A'); my $arr = ($aquery->answer)[0]; if ( $arr->type eq 'A' ) { $self->{'_' . uc($arr->type)} = $arr->address; } } my $txt = $res->query($self->fqdn, 'TXT'); # Text::Parsewords, which is called by Net::DNS::RR::TXT can spew if ( defined( $txt )) { local $^W = 0; my $txti = 0; foreach my $txtrr ( $txt->answer ) { $self->txtdata([$txtrr->char_str_list ]); $self->index($txti++); foreach my $txtln ( $txtrr->char_str_list ) { my ($key,$val) = split(/=/,$txtln,2); $self->attribute($key, $val); } $txti++; } } $self->text($txt); return; } sub all_attrs { my $self = shift; my $index = $self->index;; if ( @_ ) { my $hash = shift; $index = (shift || 0); $self->{'_attr'}[$index] = { %{$hash} }; } my @txts; foreach ( keys(%{$self->{'_attr'}[$index]}) ) { push(@txts, sprintf('%s=%s', $_, $self->{'_attr'}[$index]{$_})); } $self->txtdata( \@txts ); return %{$self->{'_attr'}[$index]}; } sub attribute { my $self = shift; my $key = shift; my $index = $self->index; if ( @_ ) { $self->{'_attr'}[$index]{$key} = shift; } return $self->{'_attr'}[$index]{$key}; } sub type { my $self = shift; if ( @_ ) { my $type = sprintf '%s/%s', shift, shift; $type =~ s/_//g; $self->{'_type'} = $type; } return $self->{'_type'}; } sub address { my $self = shift; my $key = '_' . $self->{'_ip_type'}; if ( @_ ) { $self->{$key} = shift; } return $self->{$key}; } sub sockaddr { my $self = shift; return sockaddr_in($self->port, inet_aton($self->address)); } sub dnsrr { my $self = shift; my $type = uc(shift); my $packet; my $srv = Net::DNS::RR->new( 'type' => 'SRV', 'ttl' => $self->ttl, 'name' => $self->fqdn, 'port' => $self->port, 'priority' => ( $self->priority || 0 ), 'weight' => ( $self->weight || 0 ), 'target' => $self->hostname ); my $txt = Net::DNS::RR->new( 'type' => 'TXT', 'ttl' => $self->ttl, 'name' => $self->fqdn, 'char_str_list' => $self->txtdata ); if ($type eq 'SRV') { $packet = Net::DNS::Packet->new($self->fqdn, 'SRV', 'IN'); $packet->push('answer', $srv); } elsif ($type eq 'TXT') { $packet = Net::DNS::Packet->new($self->fqdn, 'TXT', 'IN'); $packet->push('answer', $txt); } else { my $app = (split(/\./, $self->fqdn,2))[1]; $packet = Net::DNS::Packet->new($app, 'PTR', 'IN'); $packet->push('answer', Net::DNS::RR->new( 'type' => 'PTR', 'ttl' => $self->ttl, 'ptrdname' => $self->fqdn, 'name' => $app )); $packet->push('additional', $srv, $txt); } $packet->header->qr(1); $packet->header->aa(1); $packet->header->rd(0); my @addrs = (); foreach my $type (qw(A AAAA)) { my $rr = Net::DNS::RR->new( 'type' => $type, 'ttl' => $self->ttl, 'address' => $self->{'_' . $type}, 'name' => $self->hostname ); push(@addrs, $rr) if $self->{'_' . $type}; } $packet->push('additional', @addrs); return $packet; } sub name { my $self = shift; if ( $_[0] ) { $self->{'_name'} = quotemeta($_[0]); } my $name = $self->{'_name'}; $name =~ s/\\([0-9]{3})/chr($1)/ge; $name =~ s/\\x([0-9A-Fa-f]{2})/chr(hex($1))/ge; $name =~ s/\\(.)/$1/g; return $name; } sub txtdata { my $self = shift; my $index = $self->index; if ( ref($_[0]) eq 'ARRAY' ) { my $list = shift; $self->{'_txtdata'}[$index] = [ @{$list} ]; } return $self->{'_txtdata'}[$index]; } sub AUTOLOAD { my $self = shift; my $key = $AUTOLOAD; $key =~ s/^.*:://; $key = '_' . $key; if ( @_ ) { $self->{$key} = shift; } return $self->{$key}; } 1;