Action computation for compositional software-defined networking

Software-defined networking (SDN) envisions the support of multiple applications collaboratively operating on the same traffic. Policies of applications are therefore required to being composed into a rule list that represents the union of application intents. In this context, ensuring the correctness and efficiency of composition for match fields as well as the associated actions is the fundamental requirement. Prior work however focuses only on the composition of match fields and assumes simple concatenation for action composition. We show in this paper that simple concatenation can result in incorrect behavior (for parallel composition) and inefficiency (for sequential composition) for actions composition. To address this issue, we formalized the action composition problem and prove a feasibility condition on the composition of rule actions. We then propose a graph-based approach that facilitates fast composition of action lists without action redundancy. Our proposed approach has been integrated into the CoVisor code base and the evaluation results show its fitness for purpose.