OpenOnload® is a high performance network stack for Linux, supporting TCP/UDP/IP networking with the BSD sockets API. It is unusual in that it performs network processing at user-level, bypassing the OS kernel entirely on the data path. Networking overheads are reduced considerably without sacrificing the security and resource management functionality that the kernel normally provides.

OpenOnload is compatible at the binary level with existing applications. It comprises a user-level shared library that implements the protocol stack, and a supporting kernel module. The stack addresses a number of the challenges posed to a general purpose user-level network stack including: intercepting network system calls, binary compatibility with existing applications, maintaining security, supporting the semantics of system calls such as fork() and exec(), passing sockets through Unix domain sockets and advancing the protocol when the application is not scheduled. OpenOnload also includes innovative techniques that reduce interrupt overheads and improve scalability.

OpenOnload is freely available for download, and is licenced under the GPLv2. It runs on many Linux distributions and most 2.6 kernels, and is compatible with the following network adapters:

• Solarflare Solarstorm SFN4112F (SFP+)
• Solarflare Solarstorm SFN5122F (dual SFP+)
• SMC SMC10GPCIe-XFP
• SMC SMC10GPCIe-10BT

OpenOnload contains algorithms and uses hardware interface techniques which are subject to Solarflare Communications, Inc. patent applications. Parties interested in licensing Solarflare's IP are encouraged to contact Solarflare's Intellectual Property Licensing Group at:

Director of Intellectual Property Licensing
Intellectual Property Licensing Group
Solarflare Communications, Inc.
9501 Jeronimo Road
Irvine, California 92618

Support

For help using OpenOnload and to report bugs, please email Solarflare's support team.

For other feedback, including suggestions for improving OpenOnload, please contact us here.