1. 根目录:
2. include
3. uapi
4. linux
5. tc_ematch
6. tc_em_meta.h

#ifndef __LINUX_TC_EM_META_H
#define __LINUX_TC_EM_META_H

#include <linux/types.h>
#include <linux/pkt_cls.h>

enum {
	TCA_EM_META_UNSPEC,
	TCA_EM_META_HDR,
	TCA_EM_META_LVALUE,
	TCA_EM_META_RVALUE,
	__TCA_EM_META_MAX
};
#define TCA_EM_META_MAX (__TCA_EM_META_MAX - 1)

struct tcf_meta_val {
	__u16			kind;
	__u8			shift;
	__u8			op;
};

#define TCF_META_TYPE_MASK	(0xf << 12)
#define TCF_META_TYPE(kind)	(((kind) & TCF_META_TYPE_MASK) >> 12)
#define TCF_META_ID_MASK	0x7ff
#define TCF_META_ID(kind)	((kind) & TCF_META_ID_MASK)

enum {
	TCF_META_TYPE_VAR,
	TCF_META_TYPE_INT,
	__TCF_META_TYPE_MAX
};
#define TCF_META_TYPE_MAX (__TCF_META_TYPE_MAX - 1)

enum {
	TCF_META_ID_VALUE,
	TCF_META_ID_RANDOM,
	TCF_META_ID_LOADAVG_0,
	TCF_META_ID_LOADAVG_1,
	TCF_META_ID_LOADAVG_2,
	TCF_META_ID_DEV,
	TCF_META_ID_PRIORITY,
	TCF_META_ID_PROTOCOL,
	TCF_META_ID_PKTTYPE,
	TCF_META_ID_PKTLEN,
	TCF_META_ID_DATALEN,
	TCF_META_ID_MACLEN,
	TCF_META_ID_NFMARK,
	TCF_META_ID_TCINDEX,
	TCF_META_ID_RTCLASSID,
	TCF_META_ID_RTIIF,
	TCF_META_ID_SK_FAMILY,
	TCF_META_ID_SK_STATE,
	TCF_META_ID_SK_REUSE,
	TCF_META_ID_SK_BOUND_IF,
	TCF_META_ID_SK_REFCNT,
	TCF_META_ID_SK_SHUTDOWN,
	TCF_META_ID_SK_PROTO,
	TCF_META_ID_SK_TYPE,
	TCF_META_ID_SK_RCVBUF,
	TCF_META_ID_SK_RMEM_ALLOC,
	TCF_META_ID_SK_WMEM_ALLOC,
	TCF_META_ID_SK_OMEM_ALLOC,
	TCF_META_ID_SK_WMEM_QUEUED,
	TCF_META_ID_SK_RCV_QLEN,
	TCF_META_ID_SK_SND_QLEN,
 	TCF_META_ID_SK_ERR_QLEN,
	TCF_META_ID_SK_FORWARD_ALLOCS,
	TCF_META_ID_SK_SNDBUF,
 	TCF_META_ID_SK_ALLOCS,
	__TCF_META_ID_SK_ROUTE_CAPS,	/* unimplemented but in ABI already */
 	TCF_META_ID_SK_HASH,
 	TCF_META_ID_SK_LINGERTIME,
 	TCF_META_ID_SK_ACK_BACKLOG,
 	TCF_META_ID_SK_MAX_ACK_BACKLOG,
 	TCF_META_ID_SK_PRIO,
 	TCF_META_ID_SK_RCVLOWAT,
 	TCF_META_ID_SK_RCVTIMEO,
 	TCF_META_ID_SK_SNDTIMEO,
 	TCF_META_ID_SK_SENDMSG_OFF,
 	TCF_META_ID_SK_WRITE_PENDING,
	TCF_META_ID_VLAN_TAG,
	TCF_META_ID_RXHASH,
	__TCF_META_ID_MAX
};
#define TCF_META_ID_MAX (__TCF_META_ID_MAX - 1)

struct tcf_meta_hdr {
	struct tcf_meta_val	left;
	struct tcf_meta_val	right;
};

#endif