xref: /openbsd/sys/netinet/if_ether.h (revision ac5f541a)
1 /*	$OpenBSD: if_ether.h,v 1.92 2024/02/14 22:41:48 bluhm Exp $	*/
2 /*	$NetBSD: if_ether.h,v 1.22 1996/05/11 13:00:00 mycroft Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)if_ether.h	8.1 (Berkeley) 6/10/93
33  */
34 
35 #ifndef _NETINET_IF_ETHER_H_
36 #define _NETINET_IF_ETHER_H_
37 
38 /*
39  * Some basic Ethernet constants.
40  */
41 #define	ETHER_ADDR_LEN	6	/* Ethernet address length		*/
42 #define ETHER_TYPE_LEN	2	/* Ethernet type field length		*/
43 #define ETHER_CRC_LEN	4	/* Ethernet CRC length			*/
44 #define ETHER_HDR_LEN	((ETHER_ADDR_LEN * 2) + ETHER_TYPE_LEN)
45 #define ETHER_MIN_LEN	64	/* Minimum frame length, CRC included	*/
46 #define ETHER_MAX_LEN	1518	/* Maximum frame length, CRC included	*/
47 #define ETHER_MAX_DIX_LEN	1536	/* Maximum DIX frame length	*/
48 
49 /*
50  * Some Ethernet extensions.
51  */
52 #define ETHER_VLAN_ENCAP_LEN	4	/* len of 802.1Q VLAN encapsulation */
53 
54 /*
55  * Mbuf adjust factor to force 32-bit alignment of IP header.
56  * Drivers should do m_adj(m, ETHER_ALIGN) when setting up a
57  * receive so the upper layers get the IP header properly aligned
58  * past the 14-byte Ethernet header.
59  */
60 #define ETHER_ALIGN	2	/* driver adjust for IP hdr alignment */
61 
62 /*
63  * The maximum supported Ethernet length and some space for encapsulation.
64  */
65 #define ETHER_MAX_HARDMTU_LEN	65435
66 
67 /*
68  * Ethernet address - 6 octets
69  */
70 struct ether_addr {
71 	u_int8_t ether_addr_octet[ETHER_ADDR_LEN];
72 };
73 
74 /*
75  * The length of the combined header.
76  */
77 struct	ether_header {
78 	u_int8_t  ether_dhost[ETHER_ADDR_LEN];
79 	u_int8_t  ether_shost[ETHER_ADDR_LEN];
80 	u_int16_t ether_type;
81 };
82 
83 /*
84  * VLAN headers.
85  */
86 
87 struct  ether_vlan_header {
88         u_char  evl_dhost[ETHER_ADDR_LEN];
89         u_char  evl_shost[ETHER_ADDR_LEN];
90         u_int16_t evl_encap_proto;
91         u_int16_t evl_tag;
92         u_int16_t evl_proto;
93 };
94 
95 #define EVL_VLID_MASK	0xFFF
96 #define EVL_VLID_NULL	0x000
97 /* 0x000 and 0xfff are reserved */
98 #define EVL_VLID_MIN	0x001
99 #define EVL_VLID_MAX	0xFFE
100 #define EVL_VLANOFTAG(tag) ((tag) & EVL_VLID_MASK)
101 
102 #define EVL_PRIO_MAX    7
103 #define EVL_PRIO_BITS   13
104 #define EVL_PRIOFTAG(tag) (((tag) >> EVL_PRIO_BITS) & 7)
105 
106 #define EVL_ENCAPLEN    4       /* length in octets of encapsulation */
107 
108 #include <net/ethertypes.h>
109 
110 #define	ETHER_IS_MULTICAST(addr) (*(addr) & 0x01) /* is address mcast/bcast? */
111 #define	ETHER_IS_BROADCAST(addr) \
112 	(((addr)[0] & (addr)[1] & (addr)[2] & \
113 	  (addr)[3] & (addr)[4] & (addr)[5]) == 0xff)
114 #define	ETHER_IS_ANYADDR(addr)		\
115 	(((addr)[0] | (addr)[1] | (addr)[2] | \
116 	  (addr)[3] | (addr)[4] | (addr)[5]) == 0x00)
117 #define	ETHER_IS_EQ(a1, a2)	(memcmp((a1), (a2), ETHER_ADDR_LEN) == 0)
118 
119 /*
120  * It can be faster to work with ethernet addresses as a uint64_t.
121  * Provide some constants and functionality centrally to better
122  * support this.
123  */
124 
125 #define ETH64_IS_MULTICAST(_e64)	((_e64) & 0x010000000000ULL)
126 #define ETH64_IS_BROADCAST(_e64)	((_e64) == 0xffffffffffffULL)
127 #define ETH64_IS_ANYADDR(_e64)		((_e64) == 0x000000000000ULL)
128 
129 #define ETH64_8021_RSVD_PREFIX		0x0180c2000000ULL
130 #define ETH64_8021_RSVD_MASK		0xfffffffffff0ULL
131 #define ETH64_IS_8021_RSVD(_e64)	\
132     (((_e64) & ETH64_8021_RSVD_MASK) == ETH64_8021_RSVD_PREFIX)
133 
134 /*
135  * Ethernet MTU constants.
136  */
137 #define	ETHERMTU	(ETHER_MAX_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
138 #define	ETHERMIN	(ETHER_MIN_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
139 
140 /*
141  * Ethernet CRC32 polynomials (big- and little-endian versions).
142  */
143 #define	ETHER_CRC_POLY_LE	0xedb88320
144 #define	ETHER_CRC_POLY_BE	0x04c11db6
145 
146 /*
147  * Ethernet Address Resolution Protocol.
148  *
149  * See RFC 826 for protocol description.  Structure below is adapted
150  * to resolving internet addresses.  Field names used correspond to
151  * RFC 826.
152  */
153 struct	ether_arp {
154 	struct	 arphdr ea_hdr;			/* fixed-size header */
155 	u_int8_t arp_sha[ETHER_ADDR_LEN];	/* sender hardware address */
156 	u_int8_t arp_spa[4];			/* sender protocol address */
157 	u_int8_t arp_tha[ETHER_ADDR_LEN];	/* target hardware address */
158 	u_int8_t arp_tpa[4];			/* target protocol address */
159 };
160 #define	arp_hrd	ea_hdr.ar_hrd
161 #define	arp_pro	ea_hdr.ar_pro
162 #define	arp_hln	ea_hdr.ar_hln
163 #define	arp_pln	ea_hdr.ar_pln
164 #define	arp_op	ea_hdr.ar_op
165 
166 struct sockaddr_inarp {
167 	u_int8_t  sin_len;
168 	u_int8_t  sin_family;
169 	u_int16_t sin_port;
170 	struct	  in_addr sin_addr;
171 	struct	  in_addr sin_srcaddr;
172 	u_int16_t sin_tos;
173 	u_int16_t sin_other;
174 #define SIN_PROXY 1
175 };
176 
177 /*
178  * IP and ethernet specific routing flags
179  */
180 #define	RTF_USETRAILERS	  RTF_PROTO1	/* use trailers */
181 #define	RTF_PERMANENT_ARP RTF_PROTO3    /* only manual overwrite of entry */
182 
183 #ifdef _KERNEL
184 
185 #include <sys/refcnt.h>
186 
187 /*
188  * Macro to map an IP multicast address to an Ethernet multicast address.
189  * The high-order 25 bits of the Ethernet address are statically assigned,
190  * and the low-order 23 bits are taken from the low end of the IP address.
191  */
192 #define ETHER_MAP_IP_MULTICAST(ipaddr, enaddr)				\
193 	/* struct in_addr *ipaddr; */					\
194 	/* u_int8_t enaddr[ETHER_ADDR_LEN]; */				\
195 do {									\
196 	(enaddr)[0] = 0x01;						\
197 	(enaddr)[1] = 0x00;						\
198 	(enaddr)[2] = 0x5e;						\
199 	(enaddr)[3] = ((u_int8_t *)ipaddr)[1] & 0x7f;			\
200 	(enaddr)[4] = ((u_int8_t *)ipaddr)[2];				\
201 	(enaddr)[5] = ((u_int8_t *)ipaddr)[3];				\
202 } while (/* CONSTCOND */ 0)
203 
204 /*
205  * Macro to map an IPv6 multicast address to an Ethernet multicast address.
206  * The high-order 16 bits of the Ethernet address are statically assigned,
207  * and the low-order 32 bits are taken from the low end of the IPv6 address.
208  */
209 #define ETHER_MAP_IPV6_MULTICAST(ip6addr, enaddr)			\
210 	/* struct in6_addr *ip6addr; */					\
211 	/* u_int8_t enaddr[ETHER_ADDR_LEN]; */				\
212 do {									\
213 	(enaddr)[0] = 0x33;						\
214 	(enaddr)[1] = 0x33;						\
215 	(enaddr)[2] = ((u_int8_t *)ip6addr)[12];			\
216 	(enaddr)[3] = ((u_int8_t *)ip6addr)[13];			\
217 	(enaddr)[4] = ((u_int8_t *)ip6addr)[14];			\
218 	(enaddr)[5] = ((u_int8_t *)ip6addr)[15];			\
219 } while (/* CONSTCOND */ 0)
220 
221 #include <net/if_var.h>	/* for "struct ifnet" */
222 
223 struct ether_brport {
224 	struct mbuf	*(*eb_input)(struct ifnet *, struct mbuf *,
225 			   uint64_t, void *);
226 	void		(*eb_port_take)(void *);
227 	void		(*eb_port_rele)(void *);
228 	void		  *eb_port;
229 };
230 
231 /*
232  * Structure shared between the ethernet driver modules and
233  * the address resolution code.  For example, each ec_softc or il_softc
234  * begins with this structure.
235  */
236 struct	arpcom {
237 	struct	 ifnet ac_if;			/* network-visible interface */
238 	u_int8_t ac_enaddr[ETHER_ADDR_LEN];	/* ethernet hardware address */
239 	char	 ac__pad[2];			/* pad for some machines */
240 	LIST_HEAD(, ether_multi) ac_multiaddrs;	/* list of multicast addrs */
241 	int	 ac_multicnt;			/* length of ac_multiaddrs */
242 	int	 ac_multirangecnt;		/* number of mcast ranges */
243 
244 	void	*ac_trunkport;
245 	const struct ether_brport *ac_brport;
246 };
247 
248 extern int arpt_keep;				/* arp resolved cache expire */
249 extern int arpt_down;				/* arp down cache expire */
250 
251 extern u_int8_t etherbroadcastaddr[ETHER_ADDR_LEN];
252 extern u_int8_t etheranyaddr[ETHER_ADDR_LEN];
253 extern u_int8_t ether_ipmulticast_min[ETHER_ADDR_LEN];
254 extern u_int8_t ether_ipmulticast_max[ETHER_ADDR_LEN];
255 
256 #ifdef NFSCLIENT
257 extern unsigned int revarp_ifidx;
258 #endif /* NFSCLIENT */
259 
260 void	revarpinput(struct ifnet *, struct mbuf *);
261 void	revarprequest(struct ifnet *);
262 int	revarpwhoarewe(struct ifnet *, struct in_addr *, struct in_addr *);
263 int	revarpwhoami(struct in_addr *, struct ifnet *);
264 
265 void	arpinit(void);
266 void	arpinput(struct ifnet *, struct mbuf *);
267 void	arprequest(struct ifnet *, u_int32_t *, u_int32_t *, u_int8_t *);
268 void	arpwhohas(struct arpcom *, struct in_addr *);
269 int	arpproxy(struct in_addr, unsigned int);
270 int	arpresolve(struct ifnet *, struct rtentry *, struct mbuf *,
271 	    struct sockaddr *, u_char *);
272 void	arp_rtrequest(struct ifnet *, int, struct rtentry *);
273 
274 void	ether_fakeaddr(struct ifnet *);
275 int	ether_addmulti(struct ifreq *, struct arpcom *);
276 int	ether_delmulti(struct ifreq *, struct arpcom *);
277 int	ether_multiaddr(struct sockaddr *, u_int8_t *, u_int8_t *);
278 void	ether_ifattach(struct ifnet *);
279 void	ether_ifdetach(struct ifnet *);
280 int	ether_ioctl(struct ifnet *, struct arpcom *, u_long, caddr_t);
281 void	ether_input(struct ifnet *, struct mbuf *);
282 int	ether_resolve(struct ifnet *, struct mbuf *, struct sockaddr *,
283 	    struct rtentry *, struct ether_header *);
284 struct mbuf *
285 	ether_encap(struct ifnet *, struct mbuf *, struct sockaddr *,
286 	    struct rtentry *, int *);
287 int	ether_output(struct ifnet *, struct mbuf *, struct sockaddr *,
288 	    struct rtentry *);
289 void	ether_rtrequest(struct ifnet *, int, struct rtentry *);
290 char	*ether_sprintf(u_char *);
291 
292 int	ether_brport_isset(struct ifnet *);
293 void	ether_brport_set(struct ifnet *, const struct ether_brport *);
294 void	ether_brport_clr(struct ifnet *);
295 const struct ether_brport *
296 	ether_brport_get(struct ifnet *);
297 const struct ether_brport *
298 	ether_brport_get_locked(struct ifnet *);
299 
300 uint64_t	ether_addr_to_e64(const struct ether_addr *);
301 void		ether_e64_to_addr(struct ether_addr *, uint64_t);
302 
303 struct ether_extracted {
304 	struct ether_header		*eh;
305 	struct ether_vlan_header	*evh;
306 	struct ip			*ip4;
307 	struct ip6_hdr			*ip6;
308 	struct tcphdr			*tcp;
309 	struct udphdr			*udp;
310 	u_int				 iplen;
311 	u_int				 iphlen;
312 	u_int				 tcphlen;
313 	u_int				 paylen;
314 };
315 
316 void ether_extract_headers(struct mbuf *, struct ether_extracted *);
317 
318 /*
319  * Ethernet multicast address structure.  There is one of these for each
320  * multicast address or range of multicast addresses that we are supposed
321  * to listen to on a particular interface.  They are kept in a linked list,
322  * rooted in the interface's arpcom structure.  (This really has nothing to
323  * do with ARP, or with the Internet address family, but this appears to be
324  * the minimally-disrupting place to put it.)
325  */
326 struct ether_multi {
327 	u_int8_t enm_addrlo[ETHER_ADDR_LEN]; /* low  or only address of range */
328 	u_int8_t enm_addrhi[ETHER_ADDR_LEN]; /* high or only address of range */
329 	struct refcnt enm_refcnt;		/* no. claims to this addr/range */
330 	LIST_ENTRY(ether_multi) enm_list;
331 };
332 
333 /*
334  * Structure used by macros below to remember position when stepping through
335  * all of the ether_multi records.
336  */
337 struct ether_multistep {
338 	struct ether_multi  *e_enm;
339 };
340 
341 /*
342  * Macro for looking up the ether_multi record for a given range of Ethernet
343  * multicast addresses connected to a given arpcom structure.  If no matching
344  * record is found, "enm" returns NULL.
345  */
346 #define ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm)			\
347 	/* u_int8_t addrlo[ETHER_ADDR_LEN]; */				\
348 	/* u_int8_t addrhi[ETHER_ADDR_LEN]; */				\
349 	/* struct arpcom *ac; */					\
350 	/* struct ether_multi *enm; */					\
351 do {									\
352 	for ((enm) = LIST_FIRST(&(ac)->ac_multiaddrs);			\
353 	    (enm) != NULL &&						\
354 	    (memcmp((enm)->enm_addrlo, (addrlo), ETHER_ADDR_LEN) != 0 ||\
355 	     memcmp((enm)->enm_addrhi, (addrhi), ETHER_ADDR_LEN) != 0);	\
356 		(enm) = LIST_NEXT((enm), enm_list));			\
357 } while (/* CONSTCOND */ 0)
358 
359 /*
360  * Macro to step through all of the ether_multi records, one at a time.
361  * The current position is remembered in "step", which the caller must
362  * provide.  ETHER_FIRST_MULTI(), below, must be called to initialize "step"
363  * and get the first record.  Both macros return a NULL "enm" when there
364  * are no remaining records.
365  */
366 #define ETHER_NEXT_MULTI(step, enm)					\
367 	/* struct ether_multistep step; */				\
368 	/* struct ether_multi *enm; */					\
369 do {									\
370 	if (((enm) = (step).e_enm) != NULL)				\
371 		(step).e_enm = LIST_NEXT((enm), enm_list);		\
372 } while (/* CONSTCOND */ 0)
373 
374 #define ETHER_FIRST_MULTI(step, ac, enm)				\
375 	/* struct ether_multistep step; */				\
376 	/* struct arpcom *ac; */					\
377 	/* struct ether_multi *enm; */					\
378 do {									\
379 	(step).e_enm = LIST_FIRST(&(ac)->ac_multiaddrs);		\
380 	ETHER_NEXT_MULTI((step), (enm));				\
381 } while (/* CONSTCOND */ 0)
382 
383 u_int32_t ether_crc32_le_update(u_int32_t crc, const u_int8_t *, size_t);
384 u_int32_t ether_crc32_be_update(u_int32_t crc, const u_int8_t *, size_t);
385 u_int32_t ether_crc32_le(const u_int8_t *, size_t);
386 u_int32_t ether_crc32_be(const u_int8_t *, size_t);
387 
388 #else /* _KERNEL */
389 
390 __BEGIN_DECLS
391 char *ether_ntoa(struct ether_addr *);
392 struct ether_addr *ether_aton(const char *);
393 int ether_ntohost(char *, struct ether_addr *);
394 int ether_hostton(const char *, struct ether_addr *);
395 int ether_line(const char *, struct ether_addr *, char *);
396 __END_DECLS
397 
398 #endif /* _KERNEL */
399 #endif /* _NETINET_IF_ETHER_H_ */
400