xref: /netbsd-src/sys/net/if_ether.h (revision f3cfa6f6ce31685c6c4a758bc430e69eb99f50a4)
1 /*	$NetBSD: if_ether.h,v 1.79 2019/05/29 10:07:30 msaitoh Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)if_ether.h	8.1 (Berkeley) 6/10/93
32  */
33 
34 #ifndef _NET_IF_ETHER_H_
35 #define _NET_IF_ETHER_H_
36 
37 #ifdef _KERNEL
38 #ifdef _KERNEL_OPT
39 #include "opt_mbuftrace.h"
40 #endif
41 #include <sys/mbuf.h>
42 #endif
43 
44 #ifndef _STANDALONE
45 #include <net/if.h>
46 #endif
47 
48 /*
49  * Some basic Ethernet constants.
50  */
51 #define	ETHER_ADDR_LEN	6	/* length of an Ethernet address */
52 #define	ETHER_TYPE_LEN	2	/* length of the Ethernet type field */
53 #define	ETHER_CRC_LEN	4	/* length of the Ethernet CRC */
54 #define	ETHER_HDR_LEN	((ETHER_ADDR_LEN * 2) + ETHER_TYPE_LEN)
55 #define	ETHER_MIN_LEN	64	/* minimum frame length, including CRC */
56 #define	ETHER_MAX_LEN	1518	/* maximum frame length, including CRC */
57 #define	ETHER_MAX_LEN_JUMBO 9018 /* maximum jumbo frame len, including CRC */
58 
59 /*
60  * Some Ethernet extensions.
61  */
62 #define	ETHER_VLAN_ENCAP_LEN	4      /* length of 802.1Q VLAN encapsulation */
63 #define	EVL_VLANOFTAG(tag)	((tag) & 4095)		/* VLAN ID */
64 #define	EVL_PRIOFTAG(tag)	(((tag) >> 13) & 7)	/* Priority */
65 #define	EVL_CFIOFTAG(tag)	(((tag) >> 12) & 1)	/* CFI */
66 #define	ETHER_PPPOE_ENCAP_LEN	8	/* length of PPPoE encapsulation */
67 
68 /*
69  * Mbuf adjust factor to force 32-bit alignment of IP header.
70  * Drivers should do m_adj(m, ETHER_ALIGN) when setting up a
71  * receive so the upper layers get the IP header properly aligned
72  * past the 14-byte Ethernet header.
73  */
74 #define	ETHER_ALIGN	2	/* driver adjust for IP hdr alignment */
75 
76 /*
77  * Ethernet address - 6 octets
78  * this is only used by the ethers(3) functions.
79  */
80 struct ether_addr {
81 	uint8_t ether_addr_octet[ETHER_ADDR_LEN];
82 } __packed;
83 
84 /*
85  * Structure of a 10Mb/s Ethernet header.
86  */
87 struct ether_header {
88 	uint8_t  ether_dhost[ETHER_ADDR_LEN];
89 	uint8_t  ether_shost[ETHER_ADDR_LEN];
90 	uint16_t ether_type;
91 } __packed;
92 
93 #include <net/ethertypes.h>
94 
95 #define	ETHER_IS_MULTICAST(addr) (*(addr) & 0x01) /* is address mcast/bcast? */
96 #define	ETHER_IS_LOCAL(addr) (*(addr) & 0x02) /* is address local? */
97 
98 #define	ETHERMTU_JUMBO	(ETHER_MAX_LEN_JUMBO - ETHER_HDR_LEN - ETHER_CRC_LEN)
99 #define	ETHERMTU	(ETHER_MAX_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
100 #define	ETHERMIN	(ETHER_MIN_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
101 
102 /*
103  * Compute the maximum frame size based on ethertype (i.e. possible
104  * encapsulation) and whether or not an FCS is present.
105  */
106 #define	ETHER_MAX_FRAME(ifp, etype, hasfcs)				\
107 	((ifp)->if_mtu + ETHER_HDR_LEN +				\
108 	 ((hasfcs) ? ETHER_CRC_LEN : 0) +				\
109 	 (((etype) == ETHERTYPE_VLAN) ? ETHER_VLAN_ENCAP_LEN : 0) +	\
110 	 (((etype) == ETHERTYPE_PPPOE) ? ETHER_PPPOE_ENCAP_LEN : 0))
111 
112 /*
113  * Ethernet CRC32 polynomials (big- and little-endian verions).
114  */
115 #define	ETHER_CRC_POLY_LE	0xedb88320
116 #define	ETHER_CRC_POLY_BE	0x04c11db6
117 
118 #ifndef _STANDALONE
119 
120 /*
121  * Ethernet-specific mbuf flags.
122  */
123 #define	M_HASFCS	M_LINK0	/* FCS included at end of frame */
124 #define	M_PROMISC	M_LINK1	/* this packet is not for us */
125 
126 #ifdef _KERNEL
127 /*
128  * Macro to map an IP multicast address to an Ethernet multicast address.
129  * The high-order 25 bits of the Ethernet address are statically assigned,
130  * and the low-order 23 bits are taken from the low end of the IP address.
131  */
132 #define ETHER_MAP_IP_MULTICAST(ipaddr, enaddr)				\
133 	/* const struct in_addr *ipaddr; */				\
134 	/* uint8_t enaddr[ETHER_ADDR_LEN]; */				\
135 do {									\
136 	(enaddr)[0] = 0x01;						\
137 	(enaddr)[1] = 0x00;						\
138 	(enaddr)[2] = 0x5e;						\
139 	(enaddr)[3] = ((const uint8_t *)ipaddr)[1] & 0x7f;		\
140 	(enaddr)[4] = ((const uint8_t *)ipaddr)[2];			\
141 	(enaddr)[5] = ((const uint8_t *)ipaddr)[3];			\
142 } while (/*CONSTCOND*/0)
143 /*
144  * Macro to map an IP6 multicast address to an Ethernet multicast address.
145  * The high-order 16 bits of the Ethernet address are statically assigned,
146  * and the low-order 32 bits are taken from the low end of the IP6 address.
147  */
148 #define ETHER_MAP_IPV6_MULTICAST(ip6addr, enaddr)			\
149 	/* struct in6_addr *ip6addr; */					\
150 	/* uint8_t enaddr[ETHER_ADDR_LEN]; */				\
151 {                                                                       \
152 	(enaddr)[0] = 0x33;						\
153 	(enaddr)[1] = 0x33;						\
154 	(enaddr)[2] = ((const uint8_t *)ip6addr)[12];			\
155 	(enaddr)[3] = ((const uint8_t *)ip6addr)[13];			\
156 	(enaddr)[4] = ((const uint8_t *)ip6addr)[14];			\
157 	(enaddr)[5] = ((const uint8_t *)ip6addr)[15];			\
158 }
159 #endif
160 
161 struct mii_data;
162 
163 struct ethercom;
164 
165 typedef int (*ether_cb_t)(struct ethercom *);
166 
167 /*
168  * Structure shared between the ethernet driver modules and
169  * the multicast list code.  For example, each ec_softc or il_softc
170  * begins with this structure.
171  */
172 struct ethercom {
173 	struct	ifnet ec_if;			/* network-visible interface */
174 	LIST_HEAD(, ether_multi) ec_multiaddrs;	/* list of ether multicast
175 						   addrs */
176 	int	ec_multicnt;			/* length of ec_multiaddrs
177 						   list */
178 	int	ec_capabilities;		/* capabilities, provided by
179 						   driver */
180 	int	ec_capenable;			/* tells hardware which
181 						   capabilities to enable */
182 
183 	int	ec_nvlans;			/* # VLANs on this interface */
184 	/* The device handle for the MII bus child device. */
185 	struct mii_data				*ec_mii;
186 	struct ifmedia				*ec_ifmedia;
187 	/* Called after a change to ec_if.if_flags.  Returns
188 	 * ENETRESET if the device should be reinitialized with
189 	 * ec_if.if_init, 0 on success, not 0 on failure.
190 	 */
191 	ether_cb_t				ec_ifflags_cb;
192 	kmutex_t				*ec_lock;
193 	/* Flags used only by the kernel */
194 	int					ec_flags;
195 #ifdef MBUFTRACE
196 	struct	mowner ec_rx_mowner;		/* mbufs received */
197 	struct	mowner ec_tx_mowner;		/* mbufs transmitted */
198 #endif
199 };
200 
201 #define	ETHERCAP_VLAN_MTU	0x00000001 /* VLAN-compatible MTU */
202 #define	ETHERCAP_VLAN_HWTAGGING	0x00000002 /* hardware VLAN tag support */
203 #define	ETHERCAP_JUMBO_MTU	0x00000004 /* 9000 byte MTU supported */
204 #define	ETHERCAP_VLAN_HWFILTER	0x00000008 /* iface hw can filter vlan tag */
205 #define	ETHERCAP_EEE		0x00000010 /* Energy Efficiency Ethernet */
206 #define	ETHERCAP_MASK		0x0000001f
207 
208 #define	ECCAPBITS		\
209 	"\020"			\
210 	"\1VLAN_MTU"		\
211 	"\2VLAN_HWTAGGING"	\
212 	"\3JUMBO_MTU"		\
213 	"\4VLAN_HWFILTER"	\
214 	"\5EEE"
215 
216 /* ioctl() for Ethernet capabilities */
217 struct eccapreq {
218 	char		eccr_name[IFNAMSIZ];	/* if name, e.g. "en0" */
219 	int		eccr_capabilities;	/* supported capabiliites */
220 	int		eccr_capenable;		/* capabilities enabled */
221 };
222 
223 /* sysctl for Ethernet multicast addresses */
224 struct ether_multi_sysctl {
225 	u_int   enm_refcount;
226 	uint8_t enm_addrlo[ETHER_ADDR_LEN];
227 	uint8_t enm_addrhi[ETHER_ADDR_LEN];
228 };
229 
230 #ifdef	_KERNEL
231 /*
232  * Flags for ec_flags
233  */
234 /* Store IFF_ALLMULTI in ec_flags instead of if_flags to avoid data races. */
235 #define ETHER_F_ALLMULTI	__BIT(0)
236 
237 extern const uint8_t etherbroadcastaddr[ETHER_ADDR_LEN];
238 extern const uint8_t ethermulticastaddr_slowprotocols[ETHER_ADDR_LEN];
239 extern const uint8_t ether_ipmulticast_min[ETHER_ADDR_LEN];
240 extern const uint8_t ether_ipmulticast_max[ETHER_ADDR_LEN];
241 
242 void	ether_set_ifflags_cb(struct ethercom *, ether_cb_t);
243 int	ether_ioctl(struct ifnet *, u_long, void *);
244 int	ether_addmulti(const struct sockaddr *, struct ethercom *);
245 int	ether_delmulti(const struct sockaddr *, struct ethercom *);
246 int	ether_multiaddr(const struct sockaddr *, uint8_t[], uint8_t[]);
247 void    ether_input(struct ifnet *, struct mbuf *);
248 
249 /*
250  * Ethernet multicast address structure.  There is one of these for each
251  * multicast address or range of multicast addresses that we are supposed
252  * to listen to on a particular interface.  They are kept in a linked list,
253  * rooted in the interface's ethercom structure.
254  */
255 struct ether_multi {
256 	uint8_t enm_addrlo[ETHER_ADDR_LEN]; /* low  or only address of range */
257 	uint8_t enm_addrhi[ETHER_ADDR_LEN]; /* high or only address of range */
258 	u_int	 enm_refcount;		/* no. claims to this addr/range */
259 	LIST_ENTRY(ether_multi) enm_list;
260 };
261 
262 /*
263  * Structure used by macros below to remember position when stepping through
264  * all of the ether_multi records.
265  */
266 struct ether_multistep {
267 	struct ether_multi  *e_enm;
268 };
269 
270 /*
271  * lookup the ether_multi record for a given range of Ethernet
272  * multicast addresses connected to a given ethercom structure.
273  * If no matching record is found, NULL is returned.
274  */
275 static __inline struct ether_multi *
276 ether_lookup_multi(const uint8_t *addrlo, const uint8_t *addrhi,
277     const struct ethercom *ec)
278 {
279 	struct ether_multi *enm;
280 
281 	LIST_FOREACH(enm, &ec->ec_multiaddrs, enm_list) {
282 		if (memcmp(enm->enm_addrlo, addrlo, ETHER_ADDR_LEN) != 0)
283 			continue;
284 		if (memcmp(enm->enm_addrhi, addrhi, ETHER_ADDR_LEN) != 0)
285 			continue;
286 
287 		break;
288 	}
289 
290 	return enm;
291 }
292 
293 /*
294  * step through all of the ether_multi records, one at a time.
295  * The current position is remembered in "step", which the caller must
296  * provide.  ether_first_multi(), below, must be called to initialize "step"
297  * and get the first record.  Both functions return a NULL when there
298  * are no remaining records.
299  */
300 static __inline struct ether_multi *
301 ether_next_multi(struct ether_multistep *step)
302 {
303 	struct ether_multi *enm;
304 
305 	enm = step->e_enm;
306 	if (enm != NULL)
307 		step->e_enm = LIST_NEXT(enm, enm_list);
308 
309 	return enm;
310 }
311 #define ETHER_NEXT_MULTI(step, enm) \
312 	/* struct ether_multistep step; */  \
313 	/* struct ether_multi *enm; */  \
314 	(enm) = ether_next_multi(&(step))
315 
316 static __inline struct ether_multi *
317 ether_first_multi(struct ether_multistep *step, const struct ethercom *ec)
318 {
319 
320 	step->e_enm = LIST_FIRST(&ec->ec_multiaddrs);
321 
322 	return ether_next_multi(step);
323 }
324 
325 #define ETHER_FIRST_MULTI(step, ec, enm) \
326 	/* struct ether_multistep step; */ \
327 	/* struct ethercom *ec; */ \
328 	/* struct ether_multi *enm; */ \
329 	(enm) = ether_first_multi(&(step), (ec))
330 
331 #define ETHER_LOCK(ec)		mutex_enter((ec)->ec_lock)
332 #define ETHER_UNLOCK(ec)	mutex_exit((ec)->ec_lock)
333 
334 /*
335  * Ethernet 802.1Q VLAN structures.
336  */
337 
338 /* add VLAN tag to input/received packet */
339 static __inline void
340 vlan_set_tag(struct mbuf *m, uint16_t vlantag)
341 {
342 	/* VLAN tag contains priority, CFI and VLAN ID */
343 	KASSERT((m->m_flags & M_PKTHDR) != 0);
344 	m->m_pkthdr.ether_vtag = vlantag;
345 	m->m_flags |= M_VLANTAG;
346 	return;
347 }
348 
349 static __inline bool
350 vlan_has_tag(struct mbuf *m)
351 {
352 	return (m->m_flags & M_VLANTAG) != 0;
353 }
354 
355 /* extract VLAN ID value from a VLAN tag */
356 static __inline uint16_t
357 vlan_get_tag(struct mbuf *m)
358 {
359 	KASSERT((m->m_flags & M_PKTHDR) != 0);
360 	KASSERT(m->m_flags & M_VLANTAG);
361 	return m->m_pkthdr.ether_vtag;
362 }
363 
364 /* test if any VLAN is configured for this interface */
365 #define VLAN_ATTACHED(ec)	((ec)->ec_nvlans > 0)
366 
367 void	etherinit(void);
368 void	ether_ifattach(struct ifnet *, const uint8_t *);
369 void	ether_ifdetach(struct ifnet *);
370 int	ether_mediachange(struct ifnet *);
371 void	ether_mediastatus(struct ifnet *, struct ifmediareq *);
372 
373 char	*ether_sprintf(const uint8_t *);
374 char	*ether_snprintf(char *, size_t, const uint8_t *);
375 
376 uint32_t ether_crc32_le(const uint8_t *, size_t);
377 uint32_t ether_crc32_be(const uint8_t *, size_t);
378 
379 int	ether_aton_r(u_char *, size_t, const char *);
380 int	ether_enable_vlan_mtu(struct ifnet *);
381 int	ether_disable_vlan_mtu(struct ifnet *);
382 #else
383 /*
384  * Prototype ethers(3) functions.
385  */
386 #include <sys/cdefs.h>
387 __BEGIN_DECLS
388 char *	ether_ntoa(const struct ether_addr *);
389 struct ether_addr *
390 	ether_aton(const char *);
391 int	ether_ntohost(char *, const struct ether_addr *);
392 int	ether_hostton(const char *, struct ether_addr *);
393 int	ether_line(const char *, struct ether_addr *, char *);
394 __END_DECLS
395 #endif
396 
397 #endif /* _STANDALONE */
398 
399 #endif /* !_NET_IF_ETHER_H_ */
400