Enhance the multipath connection using AF XDP sockets

Multipath is a technique that utilizes multiple links to establish an abstracted, unified connection for upper-level applications. This type of connection offers distinct advantages regarding overall bandwidth and reliability compared to regular single-path connections. Nevertheless, as the throughput and number of links increase, the associated overhead in path management and data processing increases to the extent that it may surpass the processing capacity of the CPU. This paper delves into enhancing multipath connections by leveraging Linux's XDP socket to process Tx and Rx traffic. By promptly separating the multipath traffic from the kernel's network stack with an XDP socket - a technology known for its high performance and efficiency, the connection will consume fewer resources and experience reduced latency. Furthermore, we present an implementation of this concept that can deliver a substantial increase in throughput, up to 146% when compared to connections created by link aggregation in round-robin mode, with further potential for improvement.