Virtual-machine dataplane with DHCP-server functionality
In order to provide efficient processing of Dynamic Host Control Protocol (DHCP) data flows and dynamic Internet Protocol (IP) address management, an electronic device that implements a virtual dataplane in a network may separate the DHCP data flows from other data flows. Then, the virtual dataplane may perform IP address management using one or more applications that are executed by a processor in the electronic device. In order to accelerate processing of a sequence of packets in a DHCP data flow to a destination, the virtual dataplane may look up a stored result of a look-up operation for a first packet in the sequence, so that subsequent packets in the sequence use the stored result without performing the look-up operation. Furthermore, the IP address management may include dynamically freeing up IP addresses in the network based on network activity of client devices.
1. An electronic device that implements a virtual dataplane using one or more virtual machines, wherein a given virtual machine comprises an operating system or an application environment that is configured, using software, to emulate dedicated dataplane hardware or functionality of the dedicated dataplane hardware, comprising:
an interface circuit that is configured to communicate with one or more access points;
a memory that is configured to store program instructions; and
a processor, coupled to the interface circuit and the memory, that is configured to execute the program instructions, wherein, when executed by the processor, the program instructions cause the electronic device to provide a pipeline in the virtual dataplane, wherein the pipeline comprises:
a first stage that is configured to parse packets to identify packets associated with data flows, wherein the identification is based on types of packets comprising packets associated with a Dynamic Host Control Protocol (DHCP) data flow; and
a first path that is configured to process the packets associated with the DHCP data flow that are consumed in the virtual dataplane, wherein the processing comprises Internet Protocol (IP) address management by one or more applications executed by the processor and accessed via the first path,
wherein the IP address management comprises assigning IP addresses and avoiding collisions with existing IP addresses of client devices in a network, and
wherein the virtual dataplane processes the packets associated with the DHCP data flow without using an operating-system kernel to access a DHCP server.
2. The electronic device of claim 1 , wherein the pipeline further comprises a second path that processes the packets associated with other data flows that are consumed external to the virtual dataplane; and
wherein the processing in the second path occurs with a fixed time delay.
3. The electronic device of claim 2 , wherein the processing of the packets associated with the other data flows in the second path is faster than the processing of the packets associated with the DHCP data flow in the first path.
4. The electronic device of claim 2 , wherein the processing in the first path and in the second path occur concurrently.
5. The electronic device of claim 1 , wherein the packets associated with other data flows that are identified by the first stage are subsequently dropped in the virtual dataplane.
6. The electronic device of claim 1 , wherein the IP address management comprises dynamically freeing up IP addresses in the network based on network activity of the client devices.
7. The electronic device of claim 1 , wherein the IP address management comprises: receiving an IP request associated with a client device; determining, based on a media access control (MAC) address of the client device, whether an IP address is already assigned to the client device or whether the assigned IP address has exceeded a lease time; if not, assigning a new IP address to the client device; and avoiding collisions in the network by reassigning a different IP address to another client device in the network.
8. The electronic device of claim 7 , wherein determining whether the IP address is already assigned to the client device or whether the assigned IP address has exceeded the lease time comprises a look-up operation using a hash table.
9. The electronic device of claim 8 , wherein processing of a sequence of packets associated with the DHCP data flow to a particular destination is accelerated by storing a result of the look-up operation performed for a first packet in the sequence so that subsequent packets in the sequence use the stored result without performing the look-up operation.
10. The electronic device of claim 1 , wherein the one or more applications perform Network Address Translation (NAT).
11. A non-transitory computer-readable storage medium for use in conjunction with an electronic device that implements a virtual dataplane using one or more virtual machines, wherein a given virtual machine comprises an operating system or an application environment that uses software to emulate dedicated dataplane hardware or functionality of the dedicated dataplane hardware, the computer-readable storage medium storing program instructions, wherein, when executed by the electronic device, the program instructions cause the electronic device to process packets in the virtual dataplane by performing operations comprising:
providing a pipeline in the virtual dataplane, wherein providing the pipeline comprises:
parsing, in a first stage, the packets to identify packets associated with data flows, wherein the identification is based on types of packets comprising packets associated with a Dynamic Host Control Protocol (DHCP) data flow; and
processing, in a first path, the packets associated with the DHCP data flow that are consumed in the virtual dataplane, wherein the processing comprises Internet Protocol (IP) address management by one or more applications executed by a processor in the electronic device and accessed via the first path,
wherein the IP address management comprises assigning IP addresses and avoiding collisions with existing IP addresses of client devices in a network, and
wherein the virtual dataplane processes the packets associated with the DHCP data flow without using an operating-system kernel to access a DHCP server.
12. The computer-program product of claim 11 , wherein the operations further comprise processing, in a second path, the packets associated with other data flows that are consumed external to the virtual dataplane; and
wherein the processing in the second path occurs with a fixed time delay.
13. The computer-program product of claim 11 , wherein the packets associated with other data flows that are identified by the first stage are subsequently dropped in the virtual dataplane.
14. The computer-program product of claim 11 , wherein the IP address management comprises dynamically freeing up IP addresses in the network based on network activity of the client devices.
15. The computer-program product of claim 11 , wherein the IP address management comprises: receiving an IP request associated with a client device;
determining, based on a media access control (MAC) address of the client device, whether an IP address is already assigned to the client device or whether the assigned IP address has exceeded a lease time; if not, assigning a new IP address to the client device; and avoiding collisions in the network by reassigning a different IP address to another client device in the network.
16. The computer-program product of claim 15 , wherein determining whether the IP address is already assigned to the client device or whether the assigned IP address has exceeded the lease time comprises a look-up operation using a hash table.
17. The computer-program product of claim 16 , wherein processing of a sequence of packets associated with the DHCP data flow to a particular destination is accelerated by storing a result of the look-up operation performed for a first packet in the sequence so that subsequent packets in the sequence use the stored result without performing the look-up operation.
18. A method for processing packets in an electronic device that implements a virtual dataplane using one or more virtual machines, wherein a given virtual machine comprises an operating system or an application environment that is configured, using software, to emulate dedicated dataplane hardware or functionality of the dedicated dataplane hardware, the method comprising:
parsing, in a first stage in a pipeline in the virtual dataplane, packets to identify packets associated with data flows, wherein the identification is based on types of packets comprising packets associated with a Dynamic Host Control Protocol (DHCP) data flow; and
processing, in a first path in a pipeline in the virtual dataplane, the packets associated with the DHCP data flow that are consumed in the virtual dataplane, wherein the processing comprises Internet Protocol (IP) address management by one or more applications executed by a processor in the electronic device and accessed via the first path,
wherein the IP address management comprises assigning IP addresses and avoiding collisions with existing IP addresses of client devices in a network, and
wherein the virtual dataplane processes the packets associated with the DHCP data flow without using an operating-system kernel to access a DHCP server.
19. The method of claim 18 , wherein the pipeline further comprises a second path that processes the packets associated with other data flows that are consumed external to the virtual dataplane; and
wherein the processing in the second path occurs with a fixed time delay.
20. The method of claim 18 , wherein the IP address management comprises dynamically freeing up IP addresses in the network based on network activity of the client devices.