1. 根目录:
2. include
3. net
4. netfilter
5. nft_dup.h

#ifndef _NFT_DUP_H_
#define _NFT_DUP_H_

struct nft_dup_inet {
	enum nft_registers	sreg_addr:8;
	enum nft_registers	sreg_dev:8;
};

#endif /* _NFT_DUP_H_ */