Class: UPnP::SSDP

Inherits:
Object
  • Object
show all
Defined in:
lib/UPnP/SSDP.rb

Overview

Simple Service Discovery Protocol for the UPnP Device Architecture.

Currently SSDP only handles the discovery portions of SSDP.

To listen for SSDP notifications from UPnP devices:

ssdp = SSDP.new
notifications = ssdp.listen

To discover all devices and services:

ssdp = SSDP.new
resources = ssdp.search

After a device has been found you can create a Device object for it:

UPnP::Control::Device.create resource.location

Based on code by Kazuhiro NISHIYAMA ([email protected])

Defined Under Namespace

Classes: Advertisement, Error, Notification, Response, Search

Constant Summary collapse

BROADCAST =

Default broadcast address

'239.255.255.250'
PORT =

Default port

1900
TIMEOUT =

Default timeout

1
TTL =

Default packet time to live (hops)

4

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ SSDP

Creates a new SSDP object. Use the accessors to override broadcast, port, timeout or ttl.



397
398
399
400
401
402
403
404
405
406
407
408
409
410
 
# File 'lib/UPnP/SSDP.rb', line 397

def initialize
  @broadcast = BROADCAST
  @port = PORT
  @timeout = TIMEOUT
  @ttl = TTL

  @log = nil

  @listener = nil
  @queue = Queue.new

  @search_thread = nil
  @notify_thread = nil
end

Instance Attribute Details

#broadcast ⇒ Object

Broadcast address to use when sending searches and listening for notifications



346
347
348
 
# File 'lib/UPnP/SSDP.rb', line 346

def broadcast
  @broadcast
end

#listener ⇒ Object

Listener accessor for tests.



351
352
353
 
# File 'lib/UPnP/SSDP.rb', line 351

def listener
  @listener
end

#log(level, message) ⇒ Object 



564
565
566
567
568
 
# File 'lib/UPnP/SSDP.rb', line 564

def log(level, message)
  return unless @log

  @log.send level, message
end

#notify_thread ⇒ Object (readonly)

Thread that periodically notifies for advertise



361
362
363
 
# File 'lib/UPnP/SSDP.rb', line 361

def notify_thread
  @notify_thread
end

#port ⇒ Object

Port to use for SSDP searching and listening



366
367
368
 
# File 'lib/UPnP/SSDP.rb', line 366

def port
  @port
end

#queue ⇒ Object

Queue accessor for tests



371
372
373
 
# File 'lib/UPnP/SSDP.rb', line 371

def queue
  @queue
end

#search_thread ⇒ Object (readonly)

Thread that handles search requests for advertise



376
377
378
 
# File 'lib/UPnP/SSDP.rb', line 376

def search_thread
  @search_thread
end

#socket ⇒ Object

Socket accessor for tests



381
382
383
 
# File 'lib/UPnP/SSDP.rb', line 381

def socket
  @socket
end

#timeout ⇒ Object

Time to wait for SSDP responses



386
387
388
 
# File 'lib/UPnP/SSDP.rb', line 386

def timeout
  @timeout
end

#ttl ⇒ Object

TTL for SSDP packets



391
392
393
 
# File 'lib/UPnP/SSDP.rb', line 391

def ttl
  @ttl
end

Instance Method Details

Listens for M-SEARCH requests and advertises the requested services



415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
 
# File 'lib/UPnP/SSDP.rb', line 415

def advertise(root_device, port, hosts)
  @socket ||= new_socket

  @notify_thread = Thread.start do
    loop do
      hosts.each do |host|
        uri = "http://#{host}:#{port}/description"

        send_notify uri, 'upnp:rootdevice', root_device

        root_device.devices.each do |d|
          send_notify uri, d.name, d
          send_notify uri, d.type_urn, d
        end

        root_device.services.each do |s|
          send_notify uri, s.type_urn, s
        end
      end

      sleep 60
    end
  end

  listen

  @search_thread = Thread.start do
    loop do
      search = @queue.pop

      break if search == :shutdown

      next unless Search === search

      case search.target
      when /^#{UPnP::DEVICE_SCHEMA_PREFIX}/ then
        devices = root_device.devices.select do |d|
          d.type_urn == search.target
        end

        devices.each do |d|
          hosts.each do |host|
            uri = "http://#{host}:#{port}/description"
            send_response uri, search.target, "#{d.name}::#{search.target}", d
          end
        end
      when 'upnp:rootdevice' then
        hosts.each do |host|
          uri = "http://#{host}:#{port}/description"
          send_response uri, search.target, search.target, root_device
        end
      else
        warn "Unhandled target #{search.target}"
      end
    end
  end

  sleep

ensure
  @queue.push :shutdown
  stop_listening
  @notify_thread.kill

  @socket.close if @socket and not @socket.closed?
  @socket = nil
end

#byebye(root_device, hosts) ⇒ Object 



483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
 
# File 'lib/UPnP/SSDP.rb', line 483

def byebye(root_device, hosts)
  @socket ||= new_socket

  hosts.each do |host|
    send_notify_byebye 'upnp:rootdevice', root_device

    root_device.devices.each do |d|
      send_notify_byebye d.name, d
      send_notify_byebye d.type_urn, d
    end

    root_device.services.each do |s|
      send_notify_byebye s.type_urn, s
    end
  end
end

#discover ⇒ Object

Discovers UPnP devices sending NOTIFY broadcasts.

If given a block, yields each Notification as it is received and never returns. Otherwise, discover waits for timeout seconds and returns all notifications received in that time.



507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
 
# File 'lib/UPnP/SSDP.rb', line 507

def discover
  @socket ||= new_socket

  listen

  if block_given? then
    loop do
      notification = @queue.pop

      yield notification
    end
  else
    sleep @timeout

    notifications = []
    notifications << @queue.pop until @queue.empty?
    notifications
  end
ensure
  stop_listening
  @socket.close if @socket and not @socket.closed?
  @socket = nil
end

#listen ⇒ Object

Listens for UDP packets from devices in a Thread and enqueues them for processing. Requires a socket from search or discover.



535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
 
# File 'lib/UPnP/SSDP.rb', line 535

def listen
  return @listener if @listener and @listener.alive?

  @listener = Thread.start do
    loop do
      response, (family, port, hostname, address) = @socket.recvfrom 1024

      begin
        adv = parse response

        info = case adv
               when Notification then adv.type
               when Response     then adv.target
               when Search       then adv.target
               else                   'unknown'
               end

        response =~ /\A(\S+)/
        log :debug, "SSDP recv #{$1} #{hostname}:#{port} #{info}"

        @queue << adv
      rescue
        warn $!.message
        warn $!.backtrace
      end
    end
  end
end

#new_socket ⇒ Object

Sets up a UDPSocket for multicast send and receive



573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
 
# File 'lib/UPnP/SSDP.rb', line 573

def new_socket
  membership = IPAddr.new(@broadcast).hton + IPAddr.new('0.0.0.0').hton
  ttl = [@ttl].pack 'i'

  socket = UDPSocket.new

  socket.setsockopt Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP, membership
  socket.setsockopt Socket::IPPROTO_IP, Socket::IP_MULTICAST_LOOP, "\000"
  socket.setsockopt Socket::IPPROTO_IP, Socket::IP_MULTICAST_TTL, ttl
  socket.setsockopt Socket::IPPROTO_IP, Socket::IP_TTL, ttl

  socket.bind '0.0.0.0', @port

  socket
end

#parse(response) ⇒ Object

Returns a Notification, Response or Search created from response.



592
593
594
595
596
597
598
599
600
601
602
603
 
# File 'lib/UPnP/SSDP.rb', line 592

def parse(response)
  case response
  when /\ANOTIFY/ then
    Notification.parse response
  when /\AHTTP/ then
    Response.parse response
  when /\AM-SEARCH/ then
    Search.parse response
  else
    raise Error, "Unknown response #{response[/\A.*$/]}"
  end
end

#search(*targets) ⇒ Object

Sends M-SEARCH requests looking for targets. Waits timeout seconds for responses then returns the collected responses.

Supply no arguments to search for all devices and services.

Supply :root to search for root devices only.

Supply [:device, 'device_type:version'] to search for a specific device type.

Supply [:service, 'service_type:version'] to search for a specific service type.

Supply "uuid:..." to search for a UUID.

Supply "urn:..." to search for a URN.



623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
 
# File 'lib/UPnP/SSDP.rb', line 623

def search(*targets)
  @socket ||= new_socket

  if targets.empty? then
    send_search 'ssdp:all'
  else
    targets.each do |target|
      if target == :root then
        send_search 'upnp:rootdevice'
      elsif Array === target and target.first == :device then
        target = [UPnP::DEVICE_SCHEMA_PREFIX, target.last]
        send_search target.join(':')
      elsif Array === target and target.first == :service then
        target = [UPnP::SERVICE_SCHEMA_PREFIX, target.last]
        send_search target.join(':')
      elsif String === target and target =~ /\A(urn|uuid|ssdp):/ then
        send_search target
      end
    end
  end

  listen
  sleep @timeout

  responses = []
  responses << @queue.pop until @queue.empty?
  responses
ensure
  stop_listening
  @socket.close if @socket and not @socket.closed?
  @socket = nil
end

#send_notify(uri, type, obj) ⇒ Object

Builds and sends a NOTIFY message



659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
 
# File 'lib/UPnP/SSDP.rb', line 659

def send_notify(uri, type, obj)
  if type =~ /^uuid:/ then
    name = obj.name
  else
    # HACK maybe this should be .device?
    name = "#{obj.root_device.name}::#{type}"
  end

  server_info = "Ruby UPnP/#{UPnP::VERSION}"
  device_info = "#{obj.root_device.class}/#{obj.root_device.version}"

  http_notify = <<-HTTP_NOTIFY
NOTIFY * HTTP/1.1\r
HOST: #{@broadcast}:#{@port}\r
CACHE-CONTROL: max-age=120\r
LOCATION: #{uri}\r
NT: #{type}\r
NTS: ssdp:alive\r
SERVER: #{server_info} UPnP/1.0 #{device_info}\r
USN: #{name}\r
\r
  HTTP_NOTIFY

  log :debug, "SSDP sent NOTIFY #{type}"

  @socket.send http_notify, 0, @broadcast, @port
end

#send_notify_byebye(type, obj) ⇒ Object

Builds and sends a byebye NOTIFY message



690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
 
# File 'lib/UPnP/SSDP.rb', line 690

def send_notify_byebye(type, obj)
  if type =~ /^uuid:/ then
    name = obj.name
  else
    # HACK maybe this should be .device?
    name = "#{obj.root_device.name}::#{type}"
  end

  http_notify = <<-HTTP_NOTIFY
NOTIFY * HTTP/1.1\r
HOST: #{@broadcast}:#{@port}\r
NT: #{type}\r
NTS: ssdp:byebye\r
USN: #{name}\r
\r
  HTTP_NOTIFY

  log :debug, "SSDP sent byebye #{type}"

  @socket.send http_notify, 0, @broadcast, @port
end

#send_response(uri, type, name, device) ⇒ Object

Builds and sends a response to an M-SEARCH request“



715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
 
# File 'lib/UPnP/SSDP.rb', line 715

def send_response(uri, type, name, device)
  server_info = "Ruby UPnP/#{UPnP::VERSION}"
  device_info = "#{device.root_device.class}/#{device.root_device.version}"

  http_response = <<-HTTP_RESPONSE
HTTP/1.1 200 OK\r
CACHE-CONTROL: max-age=120\r
EXT:\r
LOCATION: #{uri}\r
SERVER: #{server_info} UPnP/1.0 #{device_info}\r
ST: #{type}\r
NTS: ssdp:alive\r
USN: #{name}\r
Content-Length: 0\r
\r
  HTTP_RESPONSE

  log :debug, "SSDP sent M-SEARCH OK #{type}"

  @socket.send http_response, 0, @broadcast, @port
end

#send_search(search_target) ⇒ Object

Builds and sends an M-SEARCH request looking for search_target.



740
741
742
743
744
745
746
747
748
749
750
751
752
753
 
# File 'lib/UPnP/SSDP.rb', line 740

def send_search(search_target)
  search = <<-HTTP_REQUEST
M-SEARCH * HTTP/1.1\r
HOST: #{@broadcast}:#{@port}\r
MAN: "ssdp:discover"\r
MX: #{@timeout}\r
ST: #{search_target}\r
\r
  HTTP_REQUEST

  log :debug, "SSDP sent M-SEARCH #{search_target}"

  @socket.send search, 0, @broadcast, @port
end

#stop_listening ⇒ Object

Stops and clears the listen thread.



758
759
760
761
762
 
# File 'lib/UPnP/SSDP.rb', line 758

def stop_listening
  @listener.kill if @listener
  @queue = Queue.new
  @listener = nil
end