1. Device Driver Framework Discussion
September 2014

2. Introduce Myself Steve Dean Development Engineer Hewlett-Packard
Working on HP’s SDN Controller for the past 2 years
Contact info:

3. Agenda What is a Device Driver Framework
Use-cases to illustrate the concept
High level description of HP’s design
Discussion, Q&A

4. What is a Device Driver Framework?
A framework that provides a standard and consistent way to implement device specific functionality
Device Specific Functionality
Often referred to as “Drivers”, or “Facets”
Code that performs some function and is knowledgeable of the capabilities and limitation of a Device
Framework:
Extensible to allow dynamic support for new device types
Extensible to allow new device specific functionality to be dynamically added

5. Use-Cases Validate and Adjust FlowMods
Validate and adjust FlowMods to be sent to a device based on knowledge of the type of device
FlowMods adjustments can be made to take advantages of capabilities of the device
VLAN Configuration
Perform VLAN CRUD operations using communication protocols such as SNMP, NetConf, CLI
VxLAN Configuration
Perform VxLAN CRUD operations using communication protocols such as SNMP, NetConf
Any device specific functionality

6. Major Components Identification (Discovery) Device Type Repository
Determines the type of each device using information discovered through OpenFlow handshakes, as well as direct interaction with the device
Communicate with device to discovery configuration information that may affect the devices capabilities and limitations
Device Type Repository
Maintains identity information about the types of devices recognized by the framework
Maintains the Drivers that can use be with specific Device Types
Device Management
Maintain (persist) the discovered device information (eg, device type, port status)
API to allow applications to obtain device information
Security Credential Repository
Maintain and manage security credentials to allow interaction with devices
API to allow applications to obtain security information and populate the repository
Device Drivers
Device specific software components that make use of the information about the type of device

7. Device Supplier Service
Component Diagram
Application 9
Device Driver Service
Device Driver Manager
Device Manager
Device Service
Device Supplier Service DB 1 3
Device Type XML 8 4
OF Device Discovery
Device Supplier
Driver
Device Supplier 5 2
Device Supplier 7
AuthN can happen at 2 places:
REST (token/claim-based)
OSGi bundle (signed jar and/or pre-registration)
AuthZ can happen anywhere after AuthN 6
Key Service DB
Key Manager

8. Device Supplier Service
Component Diagram
Application
Driver
Device Manager
Device Service
Device Supplier Service DB
Key Service DB
Key Manager
AuthN can happen at 2 places:
REST (token/claim-based)
OSGi bundle (signed jar and/or pre-registration)
AuthZ can happen anywhere after AuthN

9. Device Type Repository
BaseSwitch.xml
Device Type Name = Default Switch
Device Type = HP Switch
Extends Default Switch
Vendor=HP
Device Identity Handler Driver
Interface Handler Driver
Notification Handler Driver
HP.xml
Cisco.xml
3800.xml
5400.xml
5900.xml
Device Type = 5400
Extends HP Switch
Flags = isChassis
Device Type = J9642A, Extends 5400, Product=Switch 5406zl, OID= , FlowMod Driver
Device Type = J9643A, Extends 5400, Product=Switch 5412zl, OID= , FlowMod Driver 9

10. Evolution Process
Example: 5406z1 that allows V1 modules, OF info is mfr=HP, hw=5400 v1.2.3, sw=KA_1_2_3
Step 1: Use OF information (mfr=HP, hw=5400 v1.2.3, sw=KA_1_2_3) to determine the device type is HP Switch
Step 2: Use DeviceIdentityHandler Driver to fetch snmp sysOid from device
Step 3: Use sysOid to determine device is 5406zl
Step 4: We learn from the xml data that the device is a chassis
Step 5: Use DeviceIdentityHandler Driver to fetch AllowV1 mib object
Step 6: AllowV1 mib object tells us the device allows V1 modules
Device Type = Default Switch
BaseSwitch.xml
Device Type = HP Switch
Extends Default Switch
Vendor=HP
DeviceIdentityHandler Driver
HP.xml
5400.xml
Device Type = 5400
Extends HP Switch
Flags = isChassis
DeviceIdentityHandler Driver
Device Type = J9642A, Extends 5400, Product=Switch 5406zl, OID= , Facet=OpenFlow
Device Type = J9643A, Extends 5400, Product=Switch 5412zl, OID= , Facet=OpenFlow

11. Application Usage Device Service Interface Device Interface
Get Device object
Eg, Set<Device> getDevice(DeviceFilter filter)
Get Interface information
Eg, List<Interface> getInterfaces(Device device)
Device and Interface notifications
Eg, addListener(DeviceListener listener)
Device Interface
Eg, Boolean isOnline()
Eg, Set<String> getDriverrClassNames()
Eg, Boolean isSupprted(Class<? extends Driver> driverClass)
Eg, <T extends Driver> T getDriver(DriverClass<T> driverClass)

12. Q & A Is this something you think is useful?
Is there work in other areas to accomplish the same thing that I’m not aware of?

13. Backup Slides

14. ODL Architecture and Design Decisions
Device Type Repository
How to represent device type information (eg, xml)
How and where to store in-memory device type information (MD-SAL data store)
Define how new device type information can be dynamically added to the system
Identification (Discovery)
Define phase 1 discovery components (OpenFlow, Manual)
Define “evolution” process
Device Management
Do we want to maintain device information
Define how to store in-memory device information and what should be stored (MD-SAL data store)
Define API

15. ODL Architecture and Design Decisions continued
Security Repository
Define how to store security information (MD-SAL data store)
Define how to populate security repository
Define API
Device Drivers
Define how to implement device drivers
Can device drivers be implemented as “routed” RPCs and associated with a device inventory node in the MD-SAL data store?
Define how new device drivers can be dynamically added to the system

16. ODL Component Diagram – Option 1
Application
Driver
3800
Driver 5400
MD-SAL
Nodes
Routed RPCS ID
Driver
5400
VLAN Driver 5400
3800
VLAN Driver 3800
Node
5400
3800
Identification (Discovery) determines device type and augments data store and registers Routed RPC. Applications use MD-SAL services.
Augment Data Store
Register
RPCs
AuthN can happen at 2 places:
REST (token/claim-based)
OSGi bundle (signed jar and/or pre-registration)
AuthZ can happen anywhere after AuthN
GUI/REST/
Notification
Identification (Discovery)
Credential Manager
Device Driver Manager

17. ODL Component Diagram – Option 2
Hide MD-SAL from Applications
Application
Device Manager
Driver
3800
Driver 5400
MD-SAL
Nodes
Routed RPCS ID
Driver
5400
VLAN Driver 5400
3800
VLAN Driver 3800
Node
5400
3800
Augment Data Store
Register
RPCs
AuthN can happen at 2 places:
REST (token/claim-based)
OSGi bundle (signed jar and/or pre-registration)
AuthZ can happen anywhere after AuthN
GUI/REST/
Notification
Identification (discovery)
Credential Manager
Device Driver Manager

18. ODL Component Diagram – Option 3
Application
Driver
3800
Driver 5400
Device Manager
Nodes
MD-SAL
Routed RPCS
Augment Data Store ID
Driver
5400
VLAN Driver 5400
3800
VLAN Driver 3800
Node
5400
3800
Register
RPCs
Device Manger provides Application API and Identification API. Device Manager is the only component that is MD-SAL aware.
Augment Data Store
Register
RPCs
AuthN can happen at 2 places:
REST (token/claim-based)
OSGi bundle (signed jar and/or pre-registration)
AuthZ can happen anywhere after AuthN
GUI/REST/
Notification
Identification (Discovery)
Credential Manager
Device Driver Manager

19. Terminology
Facet: Software that is used to perform a function that does not require interaction with the device, but required knowledge of the device.
Eg, FlowMod Facet (validate and adjust FlowMods based on hardware capabilities and limitations).
HandlerFacet: Software that is used to perform a function that requires interaction with a device.
Eg, interact with a device to discover how it’s configured.
Eg, VxLAN Tunnel Endpoint configuration.
Facets and HandlerFacets are associated with a specific type of device and their implementation is specified in the Device Type XML file.

20. HP.xml
<deviceDriver description="HP device driver for switches">
<type name="HP Switch" extends="Default Switch">
<facet name="com.hp.device.DeviceIdentityHandler"
class="com.hp.sdn.dvc.facet.impl.HpDeviceIdentityHandler"/>
<facet name="com.hp.sdn.dvc.facet.InterfaceHandler"
class="com.hp.sdn.dvc.facet.impl.SnmpInterfaceHandler"/>
<facet name="com.hp.sdn.dvc.facet.NotificationHandler"
class="com.hp.sdn.dvc.facet.impl.SnmpNotificationHandler"/>
<vendor>HP</vendor>
</type>
</deviceDriver>

21. 5400.xml <deviceDriver description="HP 5400 Switch">
<type name="5400" extends="HP Switch">
<facet name="com.hp.sdn.dvc.facet.FlowModFacet"
class="com.hp.sdn.dvc.facet.impl.FlowModFacetFactory"/>
<family>ProCurve 5400zl</family>
<product>5400</product>
<flag name="isChassis" />
</type>
<type name="J9642A" extends="5400" description="5406zl">
<oid> </oid>
<model>J9642A</model>
<product>Switch 5406zl</product>
<type name="J9643A" extends="5400" description="5412zl">
<oid> </oid>
<model>J9643A</model>
<product>Switch 5412zl</product>
</deviceDriver>