cvsroot/AnyEvent-Porttracker/Porttracker.pm

=head1 NAME

AnyEvent::Porttracker - Porttracker/PortIQ API client interface.

=head1 SYNOPSIS

   use AnyEvent::Porttracker;

=head1 DESCRIPTION

Porttracker (L<http://www.porttracker.com/>) is a product that (among
other things) scans switches and routers in a network and gives a coherent
view of which end devices are connected to which switch ports on which
switches and routers. It also offers a JSON-based client API, for which
this module is an implementation.

In addition to Porttracker, the PortIQ product is also supported, as it
uses the same protocol.

If you do not have access to either a Porttracker or PortIQ box then this
module will be of little value to you.

This module is an L<AnyEvent> user, you need to make sure that you use and
run a supported event loop.

To quickly understand how this module works you should read how to
construct a new connection object and then read about the event/callback
system.

=head1 THE AnyEvent::Porttracker CLASS

The AnyEvent::Porttracker class represents a single connection.

=over 4

=cut

package AnyEvent::Porttracker;

use common::sense;

use Scalar::Util ();

use AnyEvent ();
use AnyEvent::Handle ();

use MIME::Base64 ();
use Digest::HMAC_MD6 ();
use JSON ();

our $VERSION = '0.0';

sub call {
   my ($self, $type, @args) = @_;

   $self->{$type}
      ? $self->{$type}($self, @args)
      : ($type = (UNIVERSAL::can $self, $type))
         ? $type->($self, @args)
         : ()
}

=item $api = new AnyEvent::Porttracker [key => value...]

Creates a new porttracker API connection object and tries to connect to
the specified host (see below). After the connection has been established,
the TLS handshake (if requested) will take place, followed by a login
attempt using either the C<none>, C<login_cram_md6> or C<login> methods,
in this order of preference (typically, C<login_cram_md6> is used, which
shields against some man-in-the-middle attacks and avoids transferring the
password).

It is permissible to send requests immediately after creating the object -
they will be queued until after successful login.

Possible key-value pairs are:

=over 4

=item host => $hostname [MANDATORY]

The hostname or IP address of the Porttracker box.

=item port => $service

The service (port) to use (default: C<porttracker=55>).

=item user => $string, pass => $string

These are the username and password to use when authentication is required
(which it is in almost all cases, so these keys are normally mandatory).

=item tls => ...

#TODO#

=item on_XYZ => $coderef

You can specify event callbacks either by subclassing and overriding the
respective methods or by specifying coderefs as key-value pairs when
constructing the object.

=back

=cut

sub new {
   my $class = shift;

   my $self = bless {
      id    => "a",
      ids   => [],
      queue => [], # ininitially queue everything
      @_,
   }, $class;

   {
      Scalar::Util::weaken (my $self = $self);

      $self->{hdl} = new AnyEvent::Handle
         connect  => [$self->{host}, $self->{port} || "porttracker=55"],
         on_error => sub {
            $self->error ();
         },
         on_connect => sub {
            if ($self->{tls}) {
               $self->_req (start_tls => sub {
                  $_[1]
                     or return $self->error ("TLS rejected by server");

                  $self->_login;
               });
            }
         },
         on_read  => sub {
            while ($_[0]{rbuf} =~ s/^([^\x0a]*)\x0a//) {
               my $msg = JSON::decode_json $1;
               my $id = shift @$msg;

               if (defined $id) {
                  my $cb = delete $self->{cb}{$id}
                     or return $self->error ("received unexpected reply msg with id $id");

                  push @{ $self->{ids} }, $id;

                  $cb->($self, @$msg);
               } else {
                  $msg->[0] = "on_$msg->[0]_notify";
                  call $self, @$msg;
               }
            }
         },
      ;
   }

   $self
}

sub DESTROY {
   my ($self) = @_;

   $self->{hdl}->destroy
      if $self->{hdl};
}

sub error {
   my ($self, $msg) = @_;

   call on_error => $msg;

   ()
}

sub _req {
   my $self = shift;
   my $cb   = pop;

   my $id   = (pop @{ $self->{ids} }) || $self->{id}++;

   unshift @_, $id;
   $self->{cb}{$id} = $cb;

   my $msg = JSON::encode_json \@_;

   $self->{hdl}->push_write ($msg);
}

=item $api->req ($type => @args, $callback->($api, @args))

Sends a generic request of type C<$type> to the server. When the server
responds, the API object and the response arguments are passed to the
callback, which is the last argument to this method.

It is permissible to call this (or any other request function) at any
time, even before the connection has been established - the API object
always waits until after login before it actually sends the requests, and
queues them until then.

Example: ping the porttracker server.

   $api->req ("ping", sub {
      my ($api, $ok, $timestamp, $pid) = @_;
      ...
   });

Example: determine the product ID.

   $api->req (product_id => sub {
      my ($api, $ok, $branding, $product_id) = @_;
      ...
   });

Example: set a new license.

   $api->req (set_license => $LICENSE_STRING, sub {
      my ($api, $ok) = @_;

      $ok or die "failed to set license";
   });

=cut

sub req {
   $_[0]{queue}
      ? push @{ $_[0]{queue} }, [@_]
      : &_req
}

sub on_start_tls_notify {
   my ($self) = @_;

   $self->{hdl}->starttls ("connect");
   $self->{tls} ||= 1;

   $self->_login;
}

sub on_hello_notify {
   my ($self, $version, $auths, $nonce) = @_;

   $version == 1
      or return $self->error ("protocol mismatch, got $version, expected/supported 1");

   $nonce = MIME::Base64::decode_base64 $nonce;

   $self->{hello} = [$auths, $nonce];

   $self->_login
      unless $self->{tls}; # delay login when trying to handshake tls
}

sub _login_success {
   my ($self, $method) = @_;

   _req @$_
      for @{ delete $self->{queue} };

   call $self, on_login => $method;
}

sub _login {
   my ($self) = @_;

   my ($auths, $nonce) = @{ delete $self->{hello} or return };

   if (grep $_ eq "none", @$auths) {
      $self->_login_success ("none");

   } elsif (grep $_ eq "login_cram_md6", @$auths) {
      my $cc = join "", map chr 256 * rand, 0..63;

      my $key = Digest::HMAC_MD6::hmac_md6 $self->{pass}, $self->{user}, 64, 256;
      my $cr  = Digest::HMAC_MD6::hmac_md6_base64 $key, "$cc$nonce", 64, 256;
      my $sr  = Digest::HMAC_MD6::hmac_md6_base64 $key, "$nonce$cc", 64, 256;

      $cc = MIME::Base64::encode_base64 $cc;

      $self->_req (login_cram_md6 => $self->{user}, $cr, $cc, sub {
         my ($self, $ok, $msg) = @_;

         $ok
            or return call $self, on_login_failure => $msg;

         $msg eq $sr
            or return call $self, on_login_failure => "sr and cr mismatch, possible man in the middle attack";

         $self->_login_success ("login_cram_md6");
      });
   } elsif (grep $_ eq "login", @$auths) {
      $self->_req (login => $self->{user}, $self->{pass}, sub {
         my ($self, $ok, $msg) = @_;

         $ok
            or return call $self, on_login_failure => $msg;

         $self->_login_success ("login");
      });
   } else {
      call $self, on_login_failure => "no supported auth method (@$auths)";
   }

   # we no longer need these, make it a bit harder to get them
   delete $self->{user};
   delete $self->{pass};
}

sub on_info_notify {
   my ($self, $msg) = @_;

   warn $msg;
}

sub on_error_notify {
   my ($self, $msg) = @_;

   $self->error ($msg);
}

sub on_error {
   my ($self, $msg) = @_;

   warn $msg;

   %$self = ();
}

sub on_login_failure {
   my ($self, $msg) = @_;

   $msg =~ s/\n$//;
   $self->error ("login failed: $msg");
}

=back

=head2 EVENTS

AnyEvent::Porttracker conenctions are fully event-driven, and naturally
there are a number of events that can occur. All these events have a name
starting with C<on_> (example: C<on_login_failure>).

Programs can catch these events in two ways: either by providing
constructor arguments with the event name as key and a coderef as value:

   my $api = new AnyEvent::Porttracker
      host => ...,
      user => ..., pass => ...,
      on_error => sub {
         my ($api, $msg) = @_;
         warn $msg;
         exit 1;
      },
   ;

Or by subclassing C<AnyEvent::Porttracker> and overriding methods of the
same name:

   package MyClass;

   use base AnyEvent::Porttracker;

   sub on_error {
      my ($api, $msg) = @_;
      warn $msg;
      exit 1;
   }

Event callbacks are not expected to return anything and are always passed
the API object as first argument. Some might have default implementations
(for example, C<on_error>), others are ignored unless overriden.

Description of individual events follow:

=over 4

=item on_error $api, $msg

Is called for every (fatal) error, including C<error> notifies. The
default prints the message and destroys the object, so it is highly
advisable to override this event.

=item on_login $api, $method

Called after a successful login, after which commands can be send. It is
permissible to send commands before a successful login: those will be
queued and sent just before this event is invoked. C<$method> is the auth
method that was used.

=item on_login_failure $api, $msg

Called when all login attempts have failed - the default raises a fatal
error with the error message from the server.

=item on_hello_notify $api, $version, $authtypes, $nonce

This protocol notification is used internally by AnyEvent::Porttracker -
you can override it, but the module will most likely not work.

=item on_info_notify $api, $msg

Called for informational messages from the server - the default
implementation calls C<warn> but otherwise ignores this notification.

=item on_error_notify $api, $msg

Called for fatal errors from the server - the default implementation calls
C<warn> and destroys the API object.

=item on_start_tls_notify $api

Called when the server wants to start TLS negotiation. This is used
internally and - while it is possible to override it - should not be
overriden.

=item on_XYZ_notify $api, ...

In general, any protocol notification will result in an event of the form
C<on_NOTIFICATION_notify>.

=back

=head1 SEE ALSO

L<AnyEvent>, L<http://www.porttracker.com/>, L<http://www.infoblox.com/en/products/portiq.html>.

=head1 AUTHOR

 Marc Lehmann <marc@porttracker.net>

=cut

1
Revision:	1.4
Committed:	Mon Nov 15 20:41:17 2010 UTC (13 years, 7 months ago) by root
Branch:	MAIN
Changes since 1.3:	+40 -2 lines
Log Message:	* empty log message *
#	Content
1	=head1 NAME
2
3	AnyEvent::Porttracker - Porttracker/PortIQ API client interface.
4
5	=head1 SYNOPSIS
6
7	use AnyEvent::Porttracker;
8
9	=head1 DESCRIPTION
10
11	Porttracker (L<http://www.porttracker.com/>) is a product that (among
12	other things) scans switches and routers in a network and gives a coherent
13	view of which end devices are connected to which switch ports on which
14	switches and routers. It also offers a JSON-based client API, for which
15	this module is an implementation.
16
17	In addition to Porttracker, the PortIQ product is also supported, as it
18	uses the same protocol.
19
20	If you do not have access to either a Porttracker or PortIQ box then this
21	module will be of little value to you.
22
23	This module is an L<AnyEvent> user, you need to make sure that you use and
24	run a supported event loop.
25
26	To quickly understand how this module works you should read how to
27	construct a new connection object and then read about the event/callback
28	system.
29
30	=head1 THE AnyEvent::Porttracker CLASS
31
32	The AnyEvent::Porttracker class represents a single connection.
33
34	=over 4
35
36	=cut
37
38	package AnyEvent::Porttracker;
39
40	use common::sense;
41
42	use Scalar::Util ();
43
44	use AnyEvent ();
45	use AnyEvent::Handle ();
46
47	use MIME::Base64 ();
48	use Digest::HMAC_MD6 ();
49	use JSON ();
50
51	our $VERSION = '0.0';
52
53	sub call {
54	my ($self, $type, @args) = @_;
55
56	$self->{$type}
57	? $self->{$type}($self, @args)
58	: ($type = (UNIVERSAL::can $self, $type))
59	? $type->($self, @args)
60	: ()
61	}
62
63	=item $api = new AnyEvent::Porttracker [key => value...]
64
65	Creates a new porttracker API connection object and tries to connect to
66	the specified host (see below). After the connection has been established,
67	the TLS handshake (if requested) will take place, followed by a login
68	attempt using either the C<none>, C<login_cram_md6> or C<login> methods,
69	in this order of preference (typically, C<login_cram_md6> is used, which
70	shields against some man-in-the-middle attacks and avoids transferring the
71	password).
72
73	It is permissible to send requests immediately after creating the object -
74	they will be queued until after successful login.
75
76	Possible key-value pairs are:
77
78	=over 4
79
80	=item host => $hostname [MANDATORY]
81
82	The hostname or IP address of the Porttracker box.
83
84	=item port => $service
85
86	The service (port) to use (default: C<porttracker=55>).
87
88	=item user => $string, pass => $string
89
90	These are the username and password to use when authentication is required
91	(which it is in almost all cases, so these keys are normally mandatory).
92
93	=item tls => ...
94
95	#TODO#
96
97	=item on_XYZ => $coderef
98
99	You can specify event callbacks either by subclassing and overriding the
100	respective methods or by specifying coderefs as key-value pairs when
101	constructing the object.
102
103	=back
104
105	=cut
106
107	sub new {
108	my $class = shift;
109
110	my $self = bless {
111	id => "a",
112	ids => [],
113	queue => [], # ininitially queue everything
114	@_,
115	}, $class;
116
117	{
118	Scalar::Util::weaken (my $self = $self);
119
120	$self->{hdl} = new AnyEvent::Handle
121	connect => [$self->{host}, $self->{port} \|\| "porttracker=55"],
122	on_error => sub {
123	$self->error ();
124	},
125	on_connect => sub {
126	if ($self->{tls}) {
127	$self->_req (start_tls => sub {
128	$_[1]
129	or return $self->error ("TLS rejected by server");
130
131	$self->_login;
132	});
133	}
134	},
135	on_read => sub {
136	while ($_[0]{rbuf} =~ s/^([^\x0a]*)\x0a//) {
137	my $msg = JSON::decode_json $1;
138	my $id = shift @$msg;
139
140	if (defined $id) {
141	my $cb = delete $self->{cb}{$id}
142	or return $self->error ("received unexpected reply msg with id $id");
143
144	push @{ $self->{ids} }, $id;
145
146	$cb->($self, @$msg);
147	} else {
148	$msg->[0] = "on_$msg->[0]_notify";
149	call $self, @$msg;
150	}
151	}
152	},
153	;
154	}
155
156	$self
157	}
158
159	sub DESTROY {
160	my ($self) = @_;
161
162	$self->{hdl}->destroy
163	if $self->{hdl};
164	}
165
166	sub error {
167	my ($self, $msg) = @_;
168
169	call on_error => $msg;
170
171	()
172	}
173
174	sub _req {
175	my $self = shift;
176	my $cb = pop;
177
178	my $id = (pop @{ $self->{ids} }) \|\| $self->{id}++;
179
180	unshift @_, $id;
181	$self->{cb}{$id} = $cb;
182
183	my $msg = JSON::encode_json \@_;
184
185	$self->{hdl}->push_write ($msg);
186	}
187
188	=item $api->req ($type => @args, $callback->($api, @args))
189
190	Sends a generic request of type C<$type> to the server. When the server
191	responds, the API object and the response arguments are passed to the
192	callback, which is the last argument to this method.
193
194	It is permissible to call this (or any other request function) at any
195	time, even before the connection has been established - the API object
196	always waits until after login before it actually sends the requests, and
197	queues them until then.
198
199	Example: ping the porttracker server.
200
201	$api->req ("ping", sub {
202	my ($api, $ok, $timestamp, $pid) = @_;
203	...
204	});
205
206	Example: determine the product ID.
207
208	$api->req (product_id => sub {
209	my ($api, $ok, $branding, $product_id) = @_;
210	...
211	});
212
213	Example: set a new license.
214
215	$api->req (set_license => $LICENSE_STRING, sub {
216	my ($api, $ok) = @_;
217
218	$ok or die "failed to set license";
219	});
220
221	=cut
222
223	sub req {
224	$_[0]{queue}
225	? push @{ $_[0]{queue} }, [@_]
226	: &_req
227	}
228
229	sub on_start_tls_notify {
230	my ($self) = @_;
231
232	$self->{hdl}->starttls ("connect");
233	$self->{tls} \|\|= 1;
234
235	$self->_login;
236	}
237
238	sub on_hello_notify {
239	my ($self, $version, $auths, $nonce) = @_;
240
241	$version == 1
242	or return $self->error ("protocol mismatch, got $version, expected/supported 1");
243
244	$nonce = MIME::Base64::decode_base64 $nonce;
245
246	$self->{hello} = [$auths, $nonce];
247
248	$self->_login
249	unless $self->{tls}; # delay login when trying to handshake tls
250	}
251
252	sub _login_success {
253	my ($self, $method) = @_;
254
255	_req @$_
256	for @{ delete $self->{queue} };
257
258	call $self, on_login => $method;
259	}
260
261	sub _login {
262	my ($self) = @_;
263
264	my ($auths, $nonce) = @{ delete $self->{hello} or return };
265
266	if (grep $_ eq "none", @$auths) {
267	$self->_login_success ("none");
268
269	} elsif (grep $_ eq "login_cram_md6", @$auths) {
270	my $cc = join "", map chr 256 * rand, 0..63;
271
272	my $key = Digest::HMAC_MD6::hmac_md6 $self->{pass}, $self->{user}, 64, 256;
273	my $cr = Digest::HMAC_MD6::hmac_md6_base64 $key, "$cc$nonce", 64, 256;
274	my $sr = Digest::HMAC_MD6::hmac_md6_base64 $key, "$nonce$cc", 64, 256;
275
276	$cc = MIME::Base64::encode_base64 $cc;
277
278	$self->_req (login_cram_md6 => $self->{user}, $cr, $cc, sub {
279	my ($self, $ok, $msg) = @_;
280
281	$ok
282	or return call $self, on_login_failure => $msg;
283
284	$msg eq $sr
285	or return call $self, on_login_failure => "sr and cr mismatch, possible man in the middle attack";
286
287	$self->_login_success ("login_cram_md6");
288	});
289	} elsif (grep $_ eq "login", @$auths) {
290	$self->_req (login => $self->{user}, $self->{pass}, sub {
291	my ($self, $ok, $msg) = @_;
292
293	$ok
294	or return call $self, on_login_failure => $msg;
295
296	$self->_login_success ("login");
297	});
298	} else {
299	call $self, on_login_failure => "no supported auth method (@$auths)";
300	}
301
302	# we no longer need these, make it a bit harder to get them
303	delete $self->{user};
304	delete $self->{pass};
305	}
306
307	sub on_info_notify {
308	my ($self, $msg) = @_;
309
310	warn $msg;
311	}
312
313	sub on_error_notify {
314	my ($self, $msg) = @_;
315
316	$self->error ($msg);
317	}
318
319	sub on_error {
320	my ($self, $msg) = @_;
321
322	warn $msg;
323
324	%$self = ();
325	}
326
327	sub on_login_failure {
328	my ($self, $msg) = @_;
329
330	$msg =~ s/\n$//;
331	$self->error ("login failed: $msg");
332	}
333
334	=back
335
336	=head2 EVENTS
337
338	AnyEvent::Porttracker conenctions are fully event-driven, and naturally
339	there are a number of events that can occur. All these events have a name
340	starting with C<on_> (example: C<on_login_failure>).
341
342	Programs can catch these events in two ways: either by providing
343	constructor arguments with the event name as key and a coderef as value:
344
345	my $api = new AnyEvent::Porttracker
346	host => ...,
347	user => ..., pass => ...,
348	on_error => sub {
349	my ($api, $msg) = @_;
350	warn $msg;
351	exit 1;
352	},
353	;
354
355	Or by subclassing C<AnyEvent::Porttracker> and overriding methods of the
356	same name:
357
358	package MyClass;
359
360	use base AnyEvent::Porttracker;
361
362	sub on_error {
363	my ($api, $msg) = @_;
364	warn $msg;
365	exit 1;
366	}
367
368	Event callbacks are not expected to return anything and are always passed
369	the API object as first argument. Some might have default implementations
370	(for example, C<on_error>), others are ignored unless overriden.
371
372	Description of individual events follow:
373
374	=over 4
375
376	=item on_error $api, $msg
377
378	Is called for every (fatal) error, including C<error> notifies. The
379	default prints the message and destroys the object, so it is highly
380	advisable to override this event.
381
382	=item on_login $api, $method
383
384	Called after a successful login, after which commands can be send. It is
385	permissible to send commands before a successful login: those will be
386	queued and sent just before this event is invoked. C<$method> is the auth
387	method that was used.
388
389	=item on_login_failure $api, $msg
390
391	Called when all login attempts have failed - the default raises a fatal
392	error with the error message from the server.
393
394	=item on_hello_notify $api, $version, $authtypes, $nonce
395
396	This protocol notification is used internally by AnyEvent::Porttracker -
397	you can override it, but the module will most likely not work.
398
399	=item on_info_notify $api, $msg
400
401	Called for informational messages from the server - the default
402	implementation calls C<warn> but otherwise ignores this notification.
403
404	=item on_error_notify $api, $msg
405
406	Called for fatal errors from the server - the default implementation calls
407	C<warn> and destroys the API object.
408
409	=item on_start_tls_notify $api
410
411	Called when the server wants to start TLS negotiation. This is used
412	internally and - while it is possible to override it - should not be
413	overriden.
414
415	=item on_XYZ_notify $api, ...
416
417	In general, any protocol notification will result in an event of the form
418	C<on_NOTIFICATION_notify>.
419
420	=back
421
422	=head1 SEE ALSO
423
424	L<AnyEvent>, L<http://www.porttracker.com/>, L<http://www.infoblox.com/en/products/portiq.html>.
425
426	=head1 AUTHOR
427
428	Marc Lehmann <marc@porttracker.net>
429
430	=cut
431
432	1