ethernet.h revision 92725 
1/*
2 * Fundamental constants relating to ethernet.
3 *
4 * $FreeBSD: head/sys/net/ethernet.h 92725 2002-03-19 21:54:18Z alfred $
5 *
6 */
7
8#ifndef _NET_ETHERNET_H_
9#define _NET_ETHERNET_H_
10
11/*
12 * The number of bytes in an ethernet (MAC) address.
13 */
14#define	ETHER_ADDR_LEN		6
15
16/*
17 * The number of bytes in the type field.
18 */
19#define	ETHER_TYPE_LEN		2
20
21/*
22 * The number of bytes in the trailing CRC field.
23 */
24#define	ETHER_CRC_LEN		4
25
26/*
27 * The length of the combined header.
28 */
29#define	ETHER_HDR_LEN		(ETHER_ADDR_LEN*2+ETHER_TYPE_LEN)
30
31/*
32 * The minimum packet length.
33 */
34#define	ETHER_MIN_LEN		64
35
36/*
37 * The maximum packet length.
38 */
39#define	ETHER_MAX_LEN		1518
40
41/*
42 * A macro to validate a length with
43 */
44#define	ETHER_IS_VALID_LEN(foo)	\
45	((foo) >= ETHER_MIN_LEN && (foo) <= ETHER_MAX_LEN)
46
47/*
48 * Structure of a 10Mb/s Ethernet header.
49 */
50struct	ether_header {
51	u_char	ether_dhost[ETHER_ADDR_LEN];
52	u_char	ether_shost[ETHER_ADDR_LEN];
53	u_short	ether_type;
54};
55
56/*
57 * Structure of a 48-bit Ethernet address.
58 */
59struct	ether_addr {
60	u_char octet[ETHER_ADDR_LEN];
61};
62
63#define	ETHERTYPE_PUP		0x0200	/* PUP protocol */
64#define	ETHERTYPE_IP		0x0800	/* IP protocol */
65#define	ETHERTYPE_ARP		0x0806	/* Addr. resolution protocol */
66#define	ETHERTYPE_REVARP	0x8035	/* reverse Addr. resolution protocol */
67#define	ETHERTYPE_VLAN		0x8100	/* IEEE 802.1Q VLAN tagging */
68#define	ETHERTYPE_IPV6		0x86dd	/* IPv6 */
69#define	ETHERTYPE_LOOPBACK	0x9000	/* used to test interfaces */
70/* XXX - add more useful types here */
71
72/*
73 * The ETHERTYPE_NTRAILER packet types starting at ETHERTYPE_TRAIL have
74 * (type-ETHERTYPE_TRAIL)*512 bytes of data followed
75 * by an ETHER type (as given above) and then the (variable-length) header.
76 */
77#define	ETHERTYPE_TRAIL		0x1000		/* Trailer packet */
78#define	ETHERTYPE_NTRAILER	16
79
80#define	ETHERMTU	(ETHER_MAX_LEN-ETHER_HDR_LEN-ETHER_CRC_LEN)
81#define	ETHERMIN	(ETHER_MIN_LEN-ETHER_HDR_LEN-ETHER_CRC_LEN)
82
83#ifdef _KERNEL
84
85/*
86 * For device drivers to specify whether they support BPF or not
87 */
88#define ETHER_BPF_UNSUPPORTED	0
89#define ETHER_BPF_SUPPORTED	1
90
91struct ifnet;
92struct mbuf;
93
94extern	void (*ng_ether_input_p)(struct ifnet *ifp,
95		struct mbuf **mp, struct ether_header *eh);
96extern	void (*ng_ether_input_orphan_p)(struct ifnet *ifp,
97		struct mbuf *m, struct ether_header *eh);
98extern	int  (*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
99extern	void (*ng_ether_attach_p)(struct ifnet *ifp);
100extern	void (*ng_ether_detach_p)(struct ifnet *ifp);
101
102extern	int (*vlan_input_p)(struct ether_header *eh, struct mbuf *m);
103extern	int (*vlan_input_tag_p)(struct ether_header *eh, struct mbuf *m,
104		u_int16_t t);
105#define _VLAN_INPUT(eh, m) do {					\
106	if (vlan_input_p != NULL) {				\
107		if ((*vlan_input_p)(eh, m) == -1)		\
108			(m)->m_pkthdr.rcvif->if_noproto++;	\
109	} else {						\
110		m_free(m);					\
111		(m)->m_pkthdr.rcvif->if_noproto++;		\
112	}							\
113} while (0)
114
115#define VLAN_INPUT(eh, m) do {					\
116	/* XXX: lock */						\
117	_VLAN_INPUT(eh, m);					\
118	/* XXX: unlock */					\
119} while (0)
120
121#define	_VLAN_INPUT_TAG(eh, m, t) do {			\
122	if (vlan_input_tag_p != NULL) { 			\
123		if ((*vlan_input_tag_p)(eh, m, t) == -1)	\
124			(m)->m_pkthdr.rcvif->if_noproto++;	\
125	} else {						\
126		m_free(m);					\
127		(m)->m_pkthdr.rcvif->if_noproto++;		\
128	}							\
129} while (0)
130
131#define VLAN_INPUT_TAG(eh, m, t) do {				\
132	/* XXX: lock */						\
133	_VLAN_INPUT_TAG(eh, m, t);				\
134	/* XXX: unlock */					\
135} while (0)
136
137#else /* _KERNEL */
138
139#include <sys/cdefs.h>
140
141/*
142 * Ethernet address conversion/parsing routines.
143 */
144__BEGIN_DECLS
145struct	ether_addr *ether_aton(const char *);
146int	ether_hostton(const char *, struct ether_addr *);
147int	ether_line(const char *, struct ether_addr *, char *);
148char 	*ether_ntoa(const struct ether_addr *);
149int	ether_ntohost(char *, const struct ether_addr *);
150__END_DECLS
151
152#endif /* !_KERNEL */
153
154#endif /* !_NET_ETHERNET_H_ */
155