Bonjour Android, it's Zeroconf

ZeroConf is a protocol that helps us advertising a service or discovering the available services in our networks. This is how Chromecast works, but why don’t we go deeper?

- What is ZeroConf
– Why is it needed
– Discovery VS Advertising
– What are the different implementations that we can find on Android
– And on server side?
– Small demo and code show

Transcript

1. IT’S ZEROCONF
   Bonjour Android
   Roberto Orgiu
   Giuseppe Mariniello
   Android Developer
   Backend Developer
   

   View Slide

2. WHAT IS ZEROCONF?
   

   View Slide

3. “ZERO-CONFIGURATION NETWORKING IS A SET OF
   TECHNOLOGIES THAT AUTOMATICALLY CREATES A USABLE
   COMPUTER NETWORK BASED ON THE INTERNET PROTOCOL
   SUITE (TCP/IP) WHEN COMPUTERS OR NETWORK
   PERIPHERALS ARE INTERCONNECTED.“
   WHAT IS ZEROCONF
   

   View Slide

4. WHAT IS ZEROCONF
   “IT DOES NOT REQUIRE MANUAL
   OPERATOR INTERVENTION OR SPECIAL
   CONFIGURATION SERVERS.“
   

   View Slide

5. WHERE CAN WE FIND
   ZEROCONF?
   

   View Slide

6. ALMOST EVERYWHERE
   

   View Slide

7. BONJOUR ANDROID, IT’S ZEROCONF
   THINK “DIFFERENT”
   ▸ ZeroConf is a standard
   ▸ UPnP/DLNA are somehow similar, but different people and ideas
   ▸ Apple has its own implementation, called Bonjour (once Rendezvous)
   ▸ On Android, we have very different solutions for using it
   

   View Slide

8. APPLE OFTEN REFERS TO ZEROCONF AS
   BONJOUR, GIVING THEIR OWN
   DEFINITION OF THE CONCEPTS
   BONJOUR ANDROID, IT’S ZEROCONF
   FUN FACT
   

   View Slide

9. Wut? Why do you even…?
   

   View Slide

10. BONJOUR ANDROID, IT’S ZEROCONF
    HOW DOES IT WORK?
    Ehy! I am 192.168.1.50
    and I have the service
    DroidConService running
    on port 56472!
    Great! Exactly what I was looking for!
    

    View Slide

11. BONJOUR ANDROID, IT’S ZEROCONF
    ▸ No infrastructure needed
    ▸ Simplicity over scalability
    ▸ 4 areas: IP interface configuration, translation between host name and IP
    address, IP multicast address allocation, service discovery
    ▸ Aware of network changes
    ▸ Still a draft
    HOW DOES IT WORK?
    

    View Slide

12. BONJOUR ANDROID, IT’S ZEROCONF
    ▸ Configure netmask
    ▸ Allocate unique IP address
    IP INTERFACE CONFIGURATION
    

    View Slide

13. BONJOUR ANDROID, IT’S ZEROCONF
    ▸ Allows hostnames to be mapped to IP addresses and back
    ▸ Failure proof with retry mechanism
    ▸ Conflict detection
    TRANSLATION BETWEEN HOST NAME AND IP ADDRESS
    

    View Slide

14. BONJOUR ANDROID, IT’S ZEROCONF
    IP MULTICAST ADDRESS ALLOCATION
    ▸ List which of the scopes (local, site-local, link-local) are available
    ▸ Select a multicast address preventing conflicts
    

    View Slide

15. BONJOUR ANDROID, IT’S ZEROCONF
    SERVICE DISCOVERY
    ▸ Service must be discoverable via identifier and/or type
    ▸ Discovery without the use of a service-specific protocol and should complete in
    a timely manner (10s of seconds)
    ▸ Prompt detection of new services in a timely manner (10s of seconds)
    D
    R
    A
    F
    T
    

    View Slide

16. BONJOUR ANDROID, IT’S ZEROCONF
    HOW DOES IT WORK?
    ▸ Each part must start with _ (underscore)
    ▸ The second part only allows _tcp or _udp
    _ServiceType._TransportProtocolName.
    List of common services goo.gl/EXh1g
    

    View Slide

17. BONJOUR ANDROID, IT’S ZEROCONF
    WHAT ABOUT ANDROID?
    ▸ API FROM 4.1
    ▸ JMDNS FOR JAVA
    ▸ APPLE NATIVE (C++) IMPLEMENTATION
    

    View Slide

18. BONJOUR ANDROID, IT’S ZEROCONF
    JMDNS FOR JAVA
    ▸ Easy to implement
    ▸ Runs on the main thread, unless we specify otherwise
    ▸ Distributed as JAR or via Maven repo
    ▸ Long start-up time
    ▸ Compatible with all the Android versions
    

    View Slide

19. BONJOUR ANDROID, IT’S ZEROCONF
    WHAT ABOUT ANDROID?
    ▸ API FROM 4.1
    ▸ JMDNS FOR JAVA
    ▸ APPLE NATIVE (C++) IMPLEMENTATION
    

    View Slide

20. BONJOUR ANDROID, IT’S ZEROCONF
    APPLE NATIVE (C++) IMPLEMENTATION
    ▸ Ported to Android by Apple
    ▸ Open-sourced
    ▸ Needs Android NDK
    ▸ Few projects come with it already packed in
    ▸ Short startup time
    ▸ More complex logic
    

    View Slide

21. BONJOUR ANDROID, IT’S ZEROCONF
    WHAT ABOUT ANDROID?
    ▸ API FROM 4.1
    ▸ JMDNS FOR JAVA
    ▸ APPLE NATIVE (C++) IMPLEMENTATION
    

    View Slide

22. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API
    ▸ From Android 4.1, custom attributes added with 5.1 (API 21)
    ▸ Already asynchronous, with return on the main thread
    ▸ Verbose, but easy to implement
    ▸ Based on two steps: discovery and resolution
    ▸ Only one service can be resolved at a time
    http://developer.android.com/training/connect-devices-wirelessly/nsd.html
    

    View Slide

23. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API - SERVER
    NsdServiceInfo serviceInfo = new NsdServiceInfo();
    serviceInfo.setServiceName("DroidConService");
    serviceInfo.setServiceType("_http._tcp.");
    serviceInfo.setPort(randomPort);
    nsdManager = Context.getSystemService(Context.NSD_SERVICE);
    nsdManager.registerService(serviceInfo,
    NsdManager.PROTOCOL_DNS_SD, mRegistrationListener);
    Remember to unregister the service upon app closing!
    

    View Slide

24. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API - CLIENT
    class Resolver extends NsdManager.ResolveListener {
    @Override
    public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {}
    @Override
    public void onServiceResolved(NsdServiceInfo serviceInfo) {
    // here we can use our resolved service
    }
    };
    Resolve resolveListener = new Resolve();
    

    View Slide

25. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API - CLIENT
    class Resolver extends NsdManager.ResolveListener {
    @Override
    public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {}
    @Override
    public void onServiceResolved(NsdServiceInfo serviceInfo) {
    // here we can use our resolved service
    }
    };
    Resolve resolveListener = new Resolve();
    

    View Slide

26. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API - CLIENT
    class SimpleDiscoveryListener extends NsdManager.DiscoveryListener {
    @Override public void onDiscoveryStarted(String regType) {}
    @Override public void onServiceFound(NsdServiceInfo service) {
    if (service.getServiceName().contains(“DroidConService")){
    nsdManager.resolveService(service, resolveListener);
    }
    }
    @Override public void onServiceLost(NsdServiceInfo service) {}
    @Override public void onDiscoveryStopped(String serviceType) {}
    @Override public void onStartDiscoveryFailed(String serviceType, int errorCode) {
    nsdManager.stopServiceDiscovery(this);
    }
    @Override public void onStopDiscoveryFailed(String serviceType, int errorCode) {
    nsdManager.stopServiceDiscovery(this);
    }};
    

    View Slide

27. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API - CLIENT
    class SimpleDiscoveryListener extends NsdManager.DiscoveryListener {
    @Override public void onDiscoveryStarted(String regType) {}
    @Override public void onServiceFound(NsdServiceInfo service) {
    if (service.getServiceName().contains(“DroidConService")){
    nsdManager.resolveService(service, resolveListener);
    }
    }
    @Override public void onServiceLost(NsdServiceInfo service) {}
    @Override public void onDiscoveryStopped(String serviceType) {}
    @Override public void onStartDiscoveryFailed(String serviceType, int errorCode) {
    nsdManager.stopServiceDiscovery(this);
    }
    @Override public void onStopDiscoveryFailed(String serviceType, int errorCode) {
    nsdManager.stopServiceDiscovery(this);
    }};
    

    View Slide

28. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API - CLIENT
    SimpleDiscoveryListener discoveryListener = new SimpleDiscoveryListener();
    nsdManager.discoverServices(SERVICE_TYPE,
    NsdManager.PROTOCOL_DNS_SD, discoveryListener);
    nsdManager.stopServiceDiscovery(discoveryListener);
    

    View Slide

29. BONJOUR ANDROID, IT’S ZEROCONF
    ANDROID API - CLIENT
    SimpleDiscoveryListener discoveryListener = new SimpleDiscoveryListener();
    nsdManager.discoverServices(SERVICE_TYPE,
    NsdManager.PROTOCOL_DNS_SD, discoveryListener);
    nsdManager.stopServiceDiscovery(discoveryListener);
    

    View Slide

30. ARE THERE BETTER
    WAYS OF DOING IT?
    

    View Slide

31. YES, THERE ARE!
    ARE THERE BETTER WAYS OF DOING IT
    

    View Slide

32. BONJOUR ANDROID, IT’S ZEROCONF
    BETTER WAYS OF DOING IT
    ▸ better-zeroconf
    ▸ RxDNSSD
    ▸ RxBonjour
    ▸ ZeRxConf
    ▸ android-mdns
    ▸ JmDNS
    ▸ Apple mDNS
    ▸ Apple mDNS
    ▸ JmDNS + Android Native APIs
    ▸ Apple mDNS
    

    View Slide

33. DEMO TIME!
    

    View Slide

34. Q & A
    CHECK THE REPO @ GITHUB.COM/ENNOVA-IT/DROIDCON-DEMO
    

    View Slide

35. BONJOUR ANDROID, IT’S ZEROCONF
    THANKS FOR WATCHING!
    

    View Slide