Adopt Smart NICs to accelerate the performance of Gatekeeper

Smart NICs can potentially help accelerate Gatekeeper's performance. Example of Smart NICs: [Netronome Agilio](https://www.netronome.com/products/smartnic/overview/).

They can be used to [accelerate DPDK-based networking applications](https://www.netronome.com/solutions/dpdk-networking-acceleration/), increasing throughput (Mpps) and bandwidth (Gb/s) to host processors. They also have some advanced offloading features: (1) VXLAN, NVGRE, MPLS, tunnel encapsulation and de-encapsulation; (2) eBPF; (3) Flexible exact and wild-card match/action policy offloads; (4) acceleration of compute-intensive functions (e.g., hashing operations), etc.

Moreover, they have on-board DRAM, caches and processors to further offload some network functionalities.

Preliminary exploration of this research direction:

(1) [AccelTCP: Accelerating Network Applications with Stateful TCP Offloading, NSDI'20](https://www.usenix.org/system/files/nsdi20spring_moon_prepub.pdf)

(2) [Introducing SmartNICs in Server-Based Data Plane Processing: The DDoS Mitigation Use Case, IEEE Access'19](https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8789414)