1. An apparatus, comprising: one or more processors; and a computer-readable non-transitory storage medium storing a program to be executed by the one or more processors, the program including instructions for: extracting matching information of a data packet in response to receiving the data packet; determining matching information for flow table match field matching, in the matching information of the data packet according to flow-table match-field configuration information, the flow-table match-field configuration information being represented by a bitmap; forming the keyword using the determined matching information; searching for a match field of each-level flow table in a multi-level flow table starting from a first-level flow table in the multi-level flow table using the keyword as a search keyword, and matching the search keyword with the match field of each-level flow table; and in response to matching a match field of a current-level flow table, executing a corresponding instruction, and in response to the current-level flow table not being a last-level flow table, or in response to an instruction for executing an action, executing a corresponding action.