以太网帧结构

struct ethhdr {
unsigned char
h_dest[ETH_ALEN]; /* destination eth addr
*/
unsigned char
h_source[ETH_ALEN]; /* source ether addr
*/
__be16
h_proto; /* packet type ID field
*/

} __attribute__((packed));

/* 协议ID，即h_proto可使用的值

 * These are the defined Ethernet Protocol ID's.

 */

#define ETH_P_LOOP 0x0060
/* Ethernet Loopback packet */

#define ETH_P_PUP 0x0200
/* Xerox PUP packet */

#define ETH_P_PUPAT 0x0201
/* Xerox PUP Addr Trans packet */

#define ETH_P_TSN 0x22F0
/* TSN (IEEE 1722) packet */

#define ETH_P_IP 0x0800
/* Internet Protocol packet */

#define ETH_P_X25 0x0805
/* CCITT X.25 */

#define ETH_P_ARP 0x0806
/* Address Resolution packet */

#define ETH_P_BPQ
0x08FF /* G8BPQ AX.25 Ethernet Packet
[ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_IEEEPUP 0x0a00
/* Xerox IEEE802.3 PUP packet */

#define ETH_P_IEEEPUPAT 0x0a01
/* Xerox IEEE802.3 PUP Addr Trans packet */

#define ETH_P_BATMAN 0x4305
/* B.A.T.M.A.N.-Advanced packet [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_DEC       0x6000          /* DEC Assigned proto           */

#define ETH_P_DNA_DL    0x6001          /* DEC DNA Dump/Load            */

#define ETH_P_DNA_RC    0x6002          /* DEC DNA Remote Console       */

#define ETH_P_DNA_RT    0x6003          /* DEC DNA Routing              */

#define ETH_P_LAT       0x6004          /* DEC LAT                      */

#define ETH_P_DIAG      0x6005          /* DEC Diagnostics              */

#define ETH_P_CUST      0x6006          /* DEC Customer use             */

#define ETH_P_SCA       0x6007          /* DEC Systems Comms Arch       */

#define ETH_P_TEB 0x6558
/* Trans Ether Bridging */

#define ETH_P_RARP      0x8035 /* Reverse Addr Res packet
*/

#define ETH_P_ATALK 0x809B
/* Appletalk DDP */

#define ETH_P_AARP 0x80F3
/* Appletalk AARP */

#define ETH_P_8021Q 0x8100          /* 802.1Q VLAN Extended Header  */

#define ETH_P_IPX 0x8137
/* IPX over DIX */

#define ETH_P_IPV6 0x86DD
/* IPv6 over bluebook */

#define ETH_P_PAUSE 0x8808
/* IEEE Pause frames. See 802.3 31B */

#define ETH_P_SLOW 0x8809
/* Slow Protocol. See 802.3ad 43B */

#define ETH_P_WCCP 0x883E
/* Web-cache coordination protocol
* defined in draft-wilson-wrec-wccp-v2-00.txt */

#define ETH_P_MPLS_UC 0x8847
/* MPLS Unicast traffic */

#define ETH_P_MPLS_MC 0x8848
/* MPLS Multicast traffic */

#define ETH_P_ATMMPOA 0x884c
/* MultiProtocol Over ATM */

#define ETH_P_PPP_DISC 0x8863
/* PPPoE discovery messages     */

#define ETH_P_PPP_SES 0x8864
/* PPPoE session messages */

#define ETH_P_LINK_CTL 0x886c
/* HPNA, wlan link local tunnel */

#define ETH_P_ATMFATE 0x8884
/* Frame-based ATM Transport
* over Ethernet
*/

#define ETH_P_PAE 0x888E
/* Port Access Entity (IEEE 802.1X) */

#define ETH_P_AOE 0x88A2
/* ATA over Ethernet */

#define ETH_P_8021AD 0x88A8          /* 802.1ad Service VLAN
*/

#define ETH_P_802_EX1 0x88B5
/* 802.1 Local Experimental 1.  */

#define ETH_P_TIPC 0x88CA
/* TIPC */

#define ETH_P_MACSEC 0x88E5
/* 802.1ae MACsec */

#define ETH_P_8021AH 0x88E7          /* 802.1ah Backbone Service Tag */

#define ETH_P_MVRP 0x88F5          /* 802.1Q MVRP                  */

#define ETH_P_1588 0x88F7
/* IEEE 1588 Timesync */

#define ETH_P_PRP 0x88FB
/* IEC 62439-3 PRP/HSRv0 */

#define ETH_P_FCOE 0x8906
/* Fibre Channel over Ethernet  */

#define ETH_P_TDLS 0x890D          /* TDLS */

#define ETH_P_FIP 0x8914
/* FCoE Initialization Protocol */

#define ETH_P_80221 0x8917
/* IEEE 802.21 Media Independent Handover Protocol */

#define ETH_P_HSR 0x892F
/* IEC 62439-3 HSRv1 */

#define ETH_P_LOOPBACK 0x9000
/* Ethernet loopback packet, per IEEE 802.3 */

#define ETH_P_QINQ1 0x9100
/* deprecated QinQ VLAN [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_QINQ2 0x9200
/* deprecated QinQ VLAN [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_QINQ3 0x9300
/* deprecated QinQ VLAN [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_EDSA 0xDADA
/* Ethertype DSA [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_AF_IUCV   0xFBFB /* IBM af_iucv [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_802_3_MIN 0x0600
/* If the value in the ethernet type is less than this value
* then the frame is Ethernet II. Else it is 802.3 */

/*

 * Non DIX types. Won't clash for 1500 types.

 */

#define ETH_P_802_3 0x0001
/* Dummy type for 802.3 frames  */

#define ETH_P_AX25 0x0002
/* Dummy protocol id for AX.25  */

#define ETH_P_ALL 0x0003
/* Every packet (be careful!!!) */

#define ETH_P_802_2 0x0004
/* 802.2 frames */

#define ETH_P_SNAP 0x0005
/* Internal only */

#define ETH_P_DDCMP     0x0006          /* DEC DDCMP: Internal only     */

#define ETH_P_WAN_PPP   0x0007          /* Dummy type for WAN PPP frames*/

#define ETH_P_PPP_MP    0x0008          /* Dummy type for PPP MP frames */

#define ETH_P_LOCALTALK 0x0009 /* Localtalk pseudo type
*/

#define ETH_P_CAN 0x000C
/* CAN: Controller Area Network */

#define ETH_P_CANFD 0x000D
/* CANFD: CAN flexible data rate*/

#define ETH_P_PPPTALK 0x0010
/* Dummy type for Atalk over PPP*/

#define ETH_P_TR_802_2 0x0011
/* 802.2 frames */

#define ETH_P_MOBITEX 0x0015
/* Mobitex (kaz@cafe.net) */

#define ETH_P_CONTROL 0x0016
/* Card specific control frames */

#define ETH_P_IRDA 0x0017
/* Linux-IrDA */

#define ETH_P_ECONET 0x0018
/* Acorn Econet */

#define ETH_P_HDLC 0x0019
/* HDLC frames */

#define ETH_P_ARCNET 0x001A
/* 1A for ArcNet :-)            */

#define ETH_P_DSA 0x001B
/* Distributed Switch Arch. */

#define ETH_P_TRAILER 0x001C
/* Trailer switch tagging */

#define ETH_P_PHONET 0x00F5
/* Nokia Phonet frames          */

#define ETH_P_IEEE802154 0x00F6 /* IEEE802.15.4 frame
*/

#define ETH_P_CAIF 0x00F7
/* ST-Ericsson CAIF protocol */

#define ETH_P_XDSA 0x00F8
/* Multiplexed DSA protocol */