Self adapting driver for controlling datapath hardware elements
View Patent ↗A self adapting driver for controlling datapath hardware elements uses a generic driver and a configuration library to create a set of data structures and methods to map information provided by applications to physical tables. A set of virtual tables is implemented as an interface between the applications and the generic driver. The generic driver uses the configuration library to determine a mapping from the virtual tables to the physical tables. A virtual table schema definition is parsed to create the configuration library, such that changes to the physical infrastructure may be implemented as changes to the virtual table schema definition without adjusting the driver code. Thus automatically generated creation of generic packet forwarding drivers is able to be implemented through the use of a configuration language that defines the meaning of the information stored in the virtual tables.
1. A method of implementing a self adapting driver for controlling datapath hardware elements of a network element, the method comprising the steps of:
providing a virtual table schema definition;
parsing the virtual table schema definition to specify a configuration library containing a set of data structures defining a mapping between a set of virtual tables and a set of physical tables used by the datapath hardware elements of the network element to make forwarding decisions for packets of data being transported on a communication network, and to specify a set of functions to be used to access the data structures;
using a generic driver to access the data structures via the set of functions to map data from records in the virtual tables to records in the physical tables.
2. The method of claim 1 , wherein the virtual table schema definition defines a format of the virtual tables.
3. The method of claim 2 , wherein the virtual table schema definition defines a format of the physical tables.
4. The method of claim 1 , wherein the virtual table schema definition is implemented in a spread sheet application program.
5. The method of claim 1 , wherein the generic driver contains a mapping function, the operation of which is wholly specified by the configuration library.
6. The method of claim 5 , further comprising changing the virtual table schema definition to create a changed virtual table schema definition, and parsing the changed virtual table schema definition to define a new mapping between the set of virtual tables and the set of physical tables without changing the mapping function.
7. The method of claim 1 , wherein the virtual table schema definition defines a virtual index table structure and defines a virtual search table structure, the virtual index table structure and virtual search table structure being accessible via an API to the virtual tables.
8. The method of claim 1 , wherein records of the virtual tables contain a number of attributes, and wherein not every attribute of the virtual tables is mapped to the same physical table.
9. The method of claim 8 , wherein subsets of the attributes of the virtual tables are mapped to different physical tables.
10. A network element, comprising:
an input interface, a forwarding interface, and an output interface, the forwarding interface interacting with physical tables to define forwarding operations on packets between the input interface and output interface;
at least one application configured to control operation of the network element through insertion of data into the physical tables, the physical tables being used by the forwarding interface to make forwarding decisions for packets of data being transported on a communication network;
a virtual table interface layer presenting to the application via an API a set of virtual tables in which the application can store the data to be inserted into the physical tables; and
a self-configuring driver intermediate the virtual table interface layer and the physical tables, the self-configuring driver being implemented as a mapping function the functionality of which is fully specified by a configuration library created by parsing a virtual table schema definition of the virtual tables.
11. The network element of claim 10 , wherein the virtual table schema definition defines a format of the virtual tables.
12. The network element of claim 11 , wherein the virtual table schema definition defines a format of the physical tables.
13. The network element of claim 10 , wherein the virtual table schema definition is implemented in a spread sheet application program.
14. The network element of claim 10 , wherein the virtual table schema definition defines a virtual index table structure and defines a virtual search table structure.
15. The network element of claim 10 , wherein records of the virtual tables contain a number of attributes, and wherein not every attribute of the virtual tables is mapped to the same physical table.
16. The network element of claim 15 , wherein subsets of the attributes of the virtual tables are mapped to different physical tables.