Hands on with lightweight m2m and Eclipse Leshan

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The Internet of Things is rising fast, but how to run it safely and efficiently using standards?

OMA Lightweight M2M is the brand new IoT protocol for managing smart objects. It provides answers to the typical IoT needs: monitoring, configuring, securing and upgrading devices.
It’s bandwidth efficient and fits in constrained embedded environments while providing friendly and discoverable RESTful API.

This tutorial aims at giving you a hands-on experience with Lightweight M2M by showing you the power and simplicity of the Eclipse Leshan library for managing real world IoT application.

- Introduction to CoAP and Lightweight M2M
- Demo and live discovery of a connected smartwatch
- Presentation of Eclipse Leshan, a lightweight M2M implementation for Java
- Code your own Java server, and start managing fleet of smartwatches!
- Presentation of more advanced lightweight M2M topic: firmware upgrade, security, bootstrap, Wakaama and Tinydtls
- Code a smartwatch application using Lightweight M2M

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Hands on with lightweight m2m and Eclipse Leshan

  1. 1. Hands-on with Lightweight M2M Run a smartwatch on the Internet-of-Things
  2. 2. Agenda Intro CoAP & Lightweight M2M Demo Eclipse Leshan Hands-on! Eclipse Wakaama Going further
  3. 3. Your devoted presenters Julien Vermillard Manuel Sangoï Simon Bernard
  4. 4. Lightweight M2M Open Mobile Alliance
  5. 5. Lightweight M2M - What is it? A reboot of OMA-DM targeting M2M Built on top of CoAP (RFC 7252) and DTLS (RFC 6347) A REST API for device management and applications
  6. 6. Device management? Operate, monitor, configure, upgrade fleets of communicating objects
  7. 7. Device management Firmware/software upgrade Configure “OTA” the device Monitor connectivity (signal, statistics,..) Reboot, reset to factory Rotate security keys In a consistent way for different hardware
  8. 8. Based on CoAP? The Constrained Application Protocol
  9. 9. A new protocol for a new world Class 1 devices ~100KiB Flash ~10KiB RAM Low-power networks <100Bytes packets
  10. 10. Where old solutions doesn’t fit Target of less than $1 for IoT SoC TCP and HTTP are not a good fit
  11. 11. CoAP - RFC 7252 RESTful protocol designed from scratch URIs, Internet Media Types GET, POST, PUT, DELETE Transparent mapping to HTTP Additional features for M2M scenarios Observe
  12. 12. Compact and binary Binary protocol - Low parsing complexity - Small message size Options - Binary HTTP-like headers 0 – 8 Bytes Token Exchange handle for client 4-byte Base Header Version | Type | T-len | Code | ID Options Location, Max-Age, ETag, … Marker 0xFF Payload Representation
  13. 13. CoAP Security Based on DTLS 1.2 (TLS for Datagrams) Focus on AES and Elliptic Curve Crypto (ECC) Pre-shared secrets, X.509, or raw public keys Hardware acceleration in IoT oriented SoC
  14. 14. LwM2M An API on top of CoAP
  15. 15. Lightweight M2M REST API for: Security, Device, Server Connectivity monitoring, Connectivity statistics Location, Firmware Upgrade, Software management, Swipe & Lock But objects have a numerical identifier
  16. 16. LwM2M URLs /{object}/{instance}/{resource} Examples: ● "/6/0" the whole location object (binary record) ● "/6/0/1" only the longitude (degree)
  17. 17. Standard objects Example: Device Manufacturer Model number Serial number Firmware version Reboot Factory reset Power sources Power V/A Battery level Memory free Error code Current time UTC offset Timezone
  18. 18. Custom objects You can define your own objects Discoverable using CoAP Link Format IPSO Alliance Smart Objects: accelerometer, temperature, sensors,...
  19. 19. Showtime! The smartwatch demo
  20. 20. Eclipse Leshan Lightweight M2M for Java
  21. 21. Leshan Java library for implementing servers & clients Friendly for any Java developer Simple (no framework, few dependencies) But also a Web UI for discovering and testing Build using “mvn install” Based on Californium and Scandium
  22. 22. History Started 22 Jul. 2013 @ Sierra Wireless First external contribution 10 March 2014 Public sandbox Jul. 2014 Proposed as an Eclipse project Sep. 2014 Client contributed Oct. 2014
  23. 23. LwM2M playground: Public sandbox http://leshan.eclipse.org Bleeding edge: deployed on master commit IPv4 and IPv6 Press “CoAP messages” for low-level traces
  24. 24. Commiters Simon Bernard - Sierra Wireless Kai Hudalla - Bosch Software Innovations Manuel Sangoï - Sierra Wireless J.F. Schloman - Zebra Technologies, Zatar Julien Vermillard - Sierra Wireless
  25. 25. Leshan Features Client initiated bootstrap Registration/Deregistration Read, Write, Create objects TLV encoding/decoding OSGi friendly: https://github.com/eclipse/leshan.osgi
  26. 26. Leshan security DTLS Pre-Shared-Key DTLS Raw-Public-Key DTLS X.509
  27. 27. Maven modules leshan-core commons elements leshan-server-core server lwm2m logic leshan-server-cf californium server leshan-client-core client lwm2m logic leshan-client-cf californium client leshan-all everything above in 1 jar leshan-client-example leshan-standalone application with web UI leshan-bs-server standalone bootstrap leshan-integration-tests
  28. 28. Server API // Build LWM2M server lwServer = new LeshanServerBuilder().build(); lwServer.getClientRegistry().addListener(new ClientRegistryListener() { @Override public void registered(Client client) { System.out.println("New registered client with endpoint: " + client.getEndpoint()); } @Override public void updated(Client clientUpdated) { System.out.println("Registration updated”); } @Override public void unregistered(Client client) { System.out.println("Registration deleted”); } }); // Start lwServer.start(); System.out.println("Demo server started");
  29. 29. Server API // Prepare the new value LwM2mResource currentTimeResource = new LwM2mResource(13, Value.newDateValue(new Date())); // Send a write request to a client WriteRequest writeCurrentTime = new WriteRequest(client, 3, 0, 13, currentTimeResource, ContentFormat.TEXT, true); ClientResponse response = lwServer.send(writeCurrentTime); System.out.println("Response to write request from client " + client.getEndpoint() + ": " +response.getCode());
  30. 30. Implements your own store ClientRegistry: Store currently registered clients SecurityRegistry: Store security informations Default implementations are “in-memory” for demo only!
  31. 31. Client API // Initialize object tree with device(3) and location(6) objects List<ObjectEnabler> enablers = new ObjectsInitializer().create(3, 6); // Create a client LeshanClient client = new LeshanClient(new InetSocketAddress("", 5683), new ArrayList<LwM2mObjectEnabler>(enablers)); // Start it client.start(); // Register to the server RegisterResponse response = client.send(new RegisterRequest("myDevice")); System.out.println("Response to register request from server : " + response.getCode());
  32. 32. Implements your own LwM2m Objects Lwm2m Object instance are mapped on Java instance. Default implementation are just stupid mock for demo only.
  33. 33. Hands-on!
  34. 34. Getting started ● Tutorial projects From the USB stick or https://github.com/msangoi/leshan-tuto ● Launch Eclipse and import the projects File > Import... > Existing projects into workspace
  35. 35. Step 1 Register a LWM2M client with a server 1. Complete the code Send a registration request to the server 2. Run a local server (leshan standalone) java -jar leshan-standalone.jar Web UI available: http://localhost:8080/#/clients 3. Run the client
  36. 36. Step 2 Define your own Device standard object 1. Complete the code a. Handle Read requests for some resources (Manufacturer model, Current timestamp…) b. Handle Write requests for Current timestamp resource c. Handle Exec requests for Reboot resource 2. Run the client (same server as Step 1)
  37. 37. Step 3 Run a server synchronizing the current time of each new registered client 1. Complete the code a. Build a leshan server b. Listen for new client registrations c. Send a write request to synchronize the current time of the client (resource with path /3/0/13) 2. Run the server 3. Test with the client from Step 2
  38. 38. Step 4 Observe the current time of a registered client 1. Update the client (from step 2) to notify when the current time value has changed 2. Complete the server code a. Listen for new observations and log the new value when a new notification is received b. Listen for new registrations and send an observe request (path /3/0/13) to the new clients
  39. 39. Going further
  40. 40. Eclipse Wakaama A C client and server implementation of LwM2M Not a shared library (.so/.dll) Embedded friendly but using malloc/free Plug your own IP stack and DTLS implementation
  41. 41. Wakaama: Features Register, registration update, deregister Read, write resources Read, write, create, delete object instances TLV or plain text Observe
  42. 42. Wakaama: Structure core : internals.h liblwm2m.c liblwm2m.h list.c management.c objects.c observe.c packet.c registration.c tlv.c transaction.c uri.c utils.c core/er-coap-13 : er-coap-13.c er-coap-13.h
  43. 43. lwm2m_object_t * get_object_device() { lwm2m_object_t * deviceObj; deviceObj = (lwm2m_object_t *)lwm2m_malloc(sizeof(lwm2m_object_t)); if (NULL != deviceObj) { memset(deviceObj, 0, sizeof(lwm2m_object_t)); deviceObj->objID = 3; deviceObj->readFunc = prv_device_read; deviceObj->writeFunc = prv_device_write; deviceObj->executeFunc = prv_device_execute; deviceObj->userData = lwm2m_malloc(sizeof(device_data_t)); if (NULL != deviceObj->userData) { ((device_data_t*)deviceObj->userData)->time = 1367491215; strcpy(((device_data_t*)deviceObj->userData)->time_offset, "+01:00"); } else { lwm2m_free(deviceObj); deviceObj = NULL; } } return deviceObj; } Create objects!
  44. 44. objArray[0] = get_object_device(); if (NULL == objArray[0]) { fprintf(stderr, "Failed to create Device objectrn"); return -1; } objArray[1] = get_object_firmware(); if (NULL == objArray[1]) { fprintf(stderr, "Failed to create Firmware objectrn"); return -1; } objArray[2] = get_test_object(); if (NULL == objArray[2]) { fprintf(stderr, "Failed to create test objectrn"); return -1; } lwm2mH = lwm2m_init(prv_connect_server, prv_buffer_send, &data); if (NULL == lwm2mH) { fprintf(stderr, "lwm2m_init() failedrn"); return -1; } result = lwm2m_configure(lwm2mH, "testlwm2mclient", BINDING_U, NULL, OBJ_COUNT, objArray); ... result = lwm2m_start(lwm2mH); Configure Wakaama!
  45. 45. while (0 == g_quit) { struct timeval tv; tv.tv_sec = 60; tv.tv_usec = 0; /* * This function does two things: * - first it does the work needed by liblwm2m (eg. (re)sending some packets). * - Secondly it adjust the timeout value (default 60s) depending on the state of the transaction * (eg. retransmission) and the time between the next operation */ result = lwm2m_step(lwm2mH, &tv); if (result != 0) { fprintf(stderr, "lwm2m_step() failed: 0x%Xrn", result); return -1; } Active Loop
  46. 46. TinyDTLS Eclipse Proposal “Support session multiplexing in single-threaded applications and thus targets specifically on embedded systems.” Examples for Linux, or Contiki OS TLS_PSK_WITH_AES_128_CCM_8 TLS_ECDHE_ECDSA_WITH_AES128_CCM_8
  47. 47. In real hardware?
  48. 48. Spark Core: Cortex-M3 STM32, RAM/ROM 20/128k, 72MHz WiFi Arduino Mega AVR, ATmega2560, RAM/ROM 8/256k, 16MHz Ethernet
  49. 49. Thank you! Questions?