Asynchronous NBTstat

This commit is contained in:
Eric A. Miller
2014-07-20 21:51:20 -04:00
parent b86ff6580e
commit e7803caa59
7 changed files with 381 additions and 47 deletions

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@@ -0,0 +1,277 @@
package App::Netdisco::AnyEvent::Nbtstat;
use Socket qw(AF_INET SOCK_DGRAM inet_aton sockaddr_in);
use List::Util ();
use Carp ();
use AnyEvent (); BEGIN { AnyEvent::common_sense }
use AnyEvent::Util ();
sub new {
my ( $class, %args ) = @_;
my $interval = $args{interval};
# This default should generate ~ 50 requests per second
$interval = 0.2 unless defined $interval;
my $timeout = $args{timeout};
# Timeout should be 250ms according to RFC1002, but we're going to double
$timeout = 0.5 unless defined $timeout;
my $self = bless { interval => $interval, timeout => $timeout, %args },
$class;
Scalar::Util::weaken( my $wself = $self );
socket my $fh4, AF_INET, Socket::SOCK_DGRAM(), 0
or Carp::croak "Unable to create socket : $!";
AnyEvent::Util::fh_nonblocking $fh4, 1;
$self->{fh4} = $fh4;
$self->{rw4} = AE::io $fh4, 0, sub {
if ( my $peer = recv $fh4, my $resp, 2048, 0 ) {
$wself->_on_read( $resp, $peer );
}
};
# Nbtstat tasks
$self->{_tasks} = {};
return $self;
}
sub interval { @_ > 1 ? $_[0]->{interval} = $_[1] : $_[0]->{interval} }
sub timeout { @_ > 1 ? $_[0]->{timeout} = $_[1] : $_[0]->{timeout} }
sub nbtstat {
my ( $self, $host, $cb ) = @_;
my $ip = inet_aton($host);
my $port = 137;
my $request = {
host => $host,
results => {},
cb => $cb,
destination => scalar sockaddr_in( $port, $ip ),
};
$self->{_tasks}{ $request->{destination} } = $request;
my $delay = $self->interval * scalar keys $self->{_tasks};
# There's probably a better way to throttle the sends
# but this will work for now since we currently don't support retries
my $w; $w = AE::timer $delay, 0, sub {
undef $w;
$self->_send_request($request);
};
return $self;
}
sub _on_read {
my ( $self, $resp, $peer ) = @_;
($resp) = $resp =~ /^(.*)$/s
if AnyEvent::TAINT && $self->{untaint};
# Find our task
my $request = $self->{_tasks}{$peer};
return unless $request;
$self->_store_result( $request, 'OK', $resp );
return;
}
sub _store_result {
my ( $self, $request, $status, $resp ) = @_;
my $results = $request->{results};
my @rr = ();
my $mac_address = "";
if ( $status eq 'OK' && length($resp) > 56 ) {
my $num_names = unpack( "C", substr( $resp, 56 ) );
my $name_data = substr( $resp, 57 );
for ( my $i = 0; $i < $num_names; $i++ ) {
my $rr_data = substr( $name_data, 18 * $i, 18 );
push @rr, _decode_rr($rr_data);
}
$mac_address = join "-",
map { sprintf "%02X", $_ }
unpack( "C*", substr( $name_data, 18 * $num_names, 6 ) );
$results = {
'status' => 'OK',
'names' => \@rr,
'mac_address' => $mac_address
};
}
elsif ( $status eq 'OK' ) {
$results = { 'status' => 'SHORT' };
}
else {
$results = { 'status' => $status };
}
# Clear request specific data
delete $request->{timer};
# Cleanup
delete $self->{_tasks}{ $request->{destination} };
# Done
$request->{cb}->($results);
undef $request;
return;
}
sub _send_request {
my ( $self, $request ) = @_;
my $msg = "";
# We use process id as identifier field, since don't have a need to
# unique responses beyond host / port queried
$msg .= pack( "n*", $$, 0, 1, 0, 0, 0 );
$msg .= _encode_name( "*", "\x00", 0 );
$msg .= pack( "n*", 0x21, 0x0001 );
$request->{start} = time;
$request->{timer} = AE::timer $self->timeout, 0, sub {
$self->_store_result( $request, 'TIMEOUT' );
};
my $fh = $self->{fh4};
send $fh, $msg, 0, $request->{destination}
or $self->_store_result( $request, 'ERROR' );
return;
}
sub _encode_name {
my $name = uc(shift);
my $pad = shift || "\x20";
my $suffix = shift || 0x00;
$name .= $pad x ( 16 - length($name) );
substr( $name, 15, 1, chr( $suffix & 0xFF ) );
my $encoded_name = "";
for my $c ( unpack( "C16", $name ) ) {
$encoded_name .= chr( ord('A') + ( ( $c & 0xF0 ) >> 4 ) );
$encoded_name .= chr( ord('A') + ( $c & 0xF ) );
}
# Note that the _encode_name function doesn't add any scope,
# nor does it calculate the length (32), it just prefixes it
return "\x20" . $encoded_name . "\x00";
}
sub _decode_rr {
my $rr_data = shift;
my @nodetypes = qw/B-node P-node M-node H-node/;
my ( $name, $suffix, $flags ) = unpack( "a15Cn", $rr_data );
$name =~ tr/\x00-\x19/\./; # replace ctrl chars with "."
$name =~ s/\s+//g;
my $rr = {};
$rr->{'name'} = $name;
$rr->{'suffix'} = $suffix;
$rr->{'G'} = ( $flags & 2**15 ) ? "GROUP" : "UNIQUE";
$rr->{'ONT'} = $nodetypes[ ( $flags >> 13 ) & 3 ];
$rr->{'DRG'} = ( $flags & 2**12 ) ? "Deregistering" : "Registered";
$rr->{'CNF'} = ( $flags & 2**11 ) ? "Conflict" : "";
$rr->{'ACT'} = ( $flags & 2**10 ) ? "Active" : "Inactive";
$rr->{'PRM'} = ( $flags & 2**9 ) ? "Permanent" : "";
return $rr;
}
1;
__END__
=head1 NAME
App::Netdisco::AnyEvent::Nbtstat - Request NetBIOS node status with AnyEvent
=head1 SYNOPSIS
use App::Netdisco::AnyEvent::Nbtstat;;
my $request = App::Netdisco::AnyEvent::Nbtstat->new();
my $cv = AE::cv;
$request->nbtstat(
'127.0.0.1',
sub {
my $result = shift;
print "MAC: ", $result->{'mac_address'} || '', " ";
print "Status: ", $result->{'status'}, "\n";
printf '%3s %-18s %4s %-18s', '', 'Name', '', 'Type'
if ( $result->{'status'} eq 'OK' );
print "\n";
for my $rr ( @{ $result->{'names'} } ) {
printf '%3s %-18s <%02s> %-18s', '', $rr->{'name'},
$rr->{'suffix'},
$rr->{'G'};
print "\n";
}
$cv->send;
}
);
$cv->recv;
=head1 DESCRIPTION
L<App::Netdisco::AnyEvent::Nbtstat> is an asynchronous AnyEvent NetBIOS node
status requester.
=head1 ATTRIBUTES
L<App::Netdisco::AnyEvent::Nbtstat> implements the following attributes.
=head2 C<interval>
my $interval = $request->interval;
$request->interval(1);
Interval between requests, defaults to 0.02 seconds.
=head2 C<timeout>
my $timeout = $request->timeout;
$request->timeout(2);
Maximum request response time, defaults to 0.5 seconds.
=head1 METHODS
L<App::Netdisco::AnyEvent::Nbtstat> implements the following methods.
=head2 C<nbtstat>
$request->nbtstat($ip, sub {
my $result = shift;
});
Perform a NetBIOS node status request of $ip.
=head1 SEE ALSO
L<AnyEvent>
=cut

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@@ -5,11 +5,11 @@ use Dancer::Plugin::DBIC 'schema';
use App::Netdisco::Util::Node 'check_mac';
use NetAddr::IP::Lite ':lower';
use Net::NBName;
use App::Netdisco::AnyEvent::Nbtstat;
use base 'Exporter';
our @EXPORT = ();
our @EXPORT_OK = qw/ do_nbtstat store_nbt /;
our @EXPORT_OK = qw/ nbtstat_resolve_async store_nbt /;
our %EXPORT_TAGS = (all => \@EXPORT_OK);
=head1 NAME
@@ -25,42 +25,64 @@ subroutines.
=head1 EXPORT_OK
=head2 do_nbtstat( $node )
=head2 nbtstat_resolve_async( $ips )
Connects to node and gets NetBIOS information. Then adds entries to
node_nbt table.
This method uses an asynchronous AnyEvent NetBIOS node status requester
C<App::Netdisco::AnyEvent::Nbtstat>.
Returns whether a node is answering netbios calls or not.
Given a reference to an array of hashes will connects to the C<IPv4> of a
node and gets NetBIOS node status information.
Returns the supplied reference to an array of hashes with MAC address,
NetBIOS name, NetBIOS domain/workgroup, NetBIOS user, and NetBIOS server
service status for addresses which responded.
=cut
sub do_nbtstat {
my ($host, $now) = @_;
my $ip = NetAddr::IP::Lite->new($host) or return;
sub nbtstat_resolve_async {
my $ips = shift;
unless ( $ip->version() == 4 ) {
debug ' nbtstat only supports IPv4, invalid ip %s', $ip->addr;
return;
my $timeout = setting('nbtstat_timeout') || 1;
my $interval = setting('nbtstat_interval') || 0.02;
my $stater = App::Netdisco::AnyEvent::Nbtstat->new(
timeout => $timeout,
interval => $interval
);
# Set up the condvar
my $cv = AE::cv;
$cv->begin( sub { shift->send } );
foreach my $hash_ref (@$ips) {
my $ip = $hash_ref->{'ip'};
$cv->begin;
$stater->nbtstat(
$ip,
sub {
my $res = shift;
_filter_nbname( $ip, $hash_ref, $res );
$cv->end;
}
);
}
my $nb = Net::NBName->new;
my $ns = $nb->node_status( $ip->addr );
# Decrement the cv counter to cancel out the send declaration
$cv->end;
# Check for NetBIOS Info
return unless $ns;
# Wait for the resolver to perform all resolutions
$cv->recv;
my $nbname = _filter_nbname( $ip->addr, $ns );
# Close sockets
undef $stater;
if ($nbname) {
store_nbt($nbname, $now);
}
return 1;
return $ips;
}
# filter nbt names / information
sub _filter_nbname {
my $ip = shift;
my $hash_ref = shift;
my $node_status = shift;
my $server = 0;
@@ -68,10 +90,10 @@ sub _filter_nbname {
my $domain = '';
my $nbuser = '';
for my $rr ( $node_status->names ) {
my $suffix = defined $rr->suffix ? $rr->suffix : -1;
my $G = defined $rr->G ? $rr->G : '';
my $name = defined $rr->name ? $rr->name : '';
for my $rr ( @{$node_status->{'names'}} ) {
my $suffix = defined $rr->{'suffix'} ? $rr->{'suffix'} : -1;
my $G = defined $rr->{'G'} ? $rr->{'G'} : '';
my $name = defined $rr->{'name'} ? $rr->{'name'} : '';
if ( $suffix == 0 and $G eq "GROUP" ) {
$domain = $name;
@@ -88,11 +110,11 @@ sub _filter_nbname {
}
unless ($nbname) {
debug ' nbtstat no computer name found for %s', $ip;
debug sprintf ' nbtstat no computer name found for %s', $ip;
return;
}
my $mac = $node_status->mac_address || '';
my $mac = $node_status->{'mac_address'} || '';
unless ( check_mac( $ip, $mac ) ) {
@@ -101,23 +123,23 @@ sub _filter_nbname {
->single( { ip => $ip, -bool => 'active' } );
if ( !defined $node_ip ) {
debug ' no MAC for %s returned by nbtstat or in DB', $ip;
debug sprintf ' no MAC for %s returned by nbtstat or in DB', $ip;
return;
}
$mac = $node_ip->mac;
}
return {
ip => $ip,
mac => $mac,
nbname => $nbname,
domain => $domain,
server => $server,
nbuser => $nbuser
};
$hash_ref->{'ip'} = $ip;
$hash_ref->{'mac'} = $mac;
$hash_ref->{'nbname'} = $nbname;
$hash_ref->{'domain'} = $domain;
$hash_ref->{'server'} = $server;
$hash_ref->{'nbuser'} = $nbuser;
return;
}
=head2 store_nbt($nb_hash_ref, $now?)
=item store_nbt($nb_hash_ref, $now?)
Stores entries in C<node_nbt> table from the provided hash reference; MAC
C<mac>, IP C<ip>, Unique NetBIOS Node Name C<nbname>, NetBIOS Domain or

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@@ -3,7 +3,7 @@ package App::Netdisco::Daemon::Worker::Poller::Nbtstat;
use Dancer qw/:moose :syntax :script/;
use Dancer::Plugin::DBIC 'schema';
use App::Netdisco::Core::Nbtstat 'do_nbtstat';
use App::Netdisco::Core::Nbtstat qw/nbtstat_resolve_async store_nbt/;
use App::Netdisco::Util::Node 'is_nbtstatable';
use App::Netdisco::Util::Device qw/get_device is_discoverable/;
use App::Netdisco::Daemon::Util ':all';
@@ -33,7 +33,7 @@ sub nbtstat {
}
# get list of nodes on device
my $interval = (setting('nbt_max_age') || 7) . ' day';
my $interval = (setting('nbtstat_max_age') || 7) . ' day';
my $rs = schema('netdisco')->resultset('NodeIp')->search({
-bool => 'me.active',
-bool => 'nodes.active',
@@ -46,10 +46,25 @@ sub nbtstat {
})->ip_version(4);
my @nodes = $rs->get_column('ip')->all;
my $now = 'to_timestamp('. (join '.', gettimeofday) .')';
$self->_single_node_body('nbtstat', $_, $now)
for @nodes;
# Unless we have IP's don't bother
if (scalar @nodes) {
# filter exclusions from config
@nodes = grep { is_nbtstatable( $_ ) } @nodes;
# setup the hash nbtstat_resolve_async expects
my @ips = map {+{'ip' => $_}} @nodes;
my $now = 'to_timestamp('. (join '.', gettimeofday) .')';
my $resolved_nodes = nbtstat_resolve_async(\@ips);
# update node_nbt with status entries
foreach my $result (@$resolved_nodes) {
if (defined $result->{'nbname'}) {
store_nbt($result, $now);
}
}
}
return job_done("Ended nbtstat for ". $host->addr);
}

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@@ -681,6 +681,20 @@ Value: Number. Default: 7.
The maximum age of a node in days for it to be checked for NetBIOS
information.
=head3 C<nbtstat_interval>
Value: Number. Default: 0.02.
Interval between nbtstat requests in each poller. Defaults to 0.02 seconds,
equating to 50 requests per second per poller.
=head3 C<nbtstat_timeout>
Value: Number. Default: 1.
Seconds nbtstat will wait for a response before time out. Accepts fractional
seconds as well as integers.
=head3 C<expire_devices>
Value: Number of Days.

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@@ -221,11 +221,9 @@ Returns false if the host is not permitted to nbtstat the target node.
sub is_nbtstatable {
my $ip = shift;
return _bail_msg("is_nbtstatable: node matched nbtstat_no")
if check_node_no($ip, 'nbtstat_no');
return if check_node_no($ip, 'nbtstat_no');
return _bail_msg("is_nbtstatable: node failed to match nbtstat_only")
unless check_node_only($ip, 'nbtstat_only');
return unless check_node_only($ip, 'nbtstat_only');
return 1;
}