xref: /freebsd/sys/net/if_var.h (revision 06064893b3c62c648518be78604fac29fc0d9d61)
1 /*
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	From: @(#)if.h	8.1 (Berkeley) 6/10/93
30  * $FreeBSD$
31  */
32 
33 #ifndef	_NET_IF_VAR_H_
34 #define	_NET_IF_VAR_H_
35 
36 /*
37  * Structures defining a network interface, providing a packet
38  * transport mechanism (ala level 0 of the PUP protocols).
39  *
40  * Each interface accepts output datagrams of a specified maximum
41  * length, and provides higher level routines with input datagrams
42  * received from its medium.
43  *
44  * Output occurs when the routine if_output is called, with three parameters:
45  *	(*ifp->if_output)(ifp, m, dst, rt)
46  * Here m is the mbuf chain to be sent and dst is the destination address.
47  * The output routine encapsulates the supplied datagram if necessary,
48  * and then transmits it on its medium.
49  *
50  * On input, each interface unwraps the data received by it, and either
51  * places it on the input queue of an internetwork datagram routine
52  * and posts the associated software interrupt, or passes the datagram to a raw
53  * packet input routine.
54  *
55  * Routines exist for locating interfaces by their addresses
56  * or for locating an interface on a certain network, as well as more general
57  * routing and gateway routines maintaining information used to locate
58  * interfaces.  These routines live in the files if.c and route.c
59  */
60 
61 #ifdef __STDC__
62 /*
63  * Forward structure declarations for function prototypes [sic].
64  */
65 struct	mbuf;
66 struct	thread;
67 struct	rtentry;
68 struct	rt_addrinfo;
69 struct	socket;
70 struct	ether_header;
71 #endif
72 
73 #include <sys/queue.h>		/* get TAILQ macros */
74 
75 #ifdef _KERNEL
76 #include <sys/mbuf.h>
77 #include <sys/eventhandler.h>
78 #endif /* _KERNEL */
79 #include <sys/lock.h>		/* XXX */
80 #include <sys/mutex.h>		/* XXX */
81 #include <sys/event.h>		/* XXX */
82 #include <sys/_task.h>
83 
84 #define	IF_DUNIT_NONE	-1
85 
86 #include <altq/if_altq.h>
87 
88 TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
89 TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
90 TAILQ_HEAD(ifprefixhead, ifprefix);
91 TAILQ_HEAD(ifmultihead, ifmultiaddr);
92 
93 /*
94  * Structure defining a queue for a network interface.
95  */
96 struct	ifqueue {
97 	struct	mbuf *ifq_head;
98 	struct	mbuf *ifq_tail;
99 	int	ifq_len;
100 	int	ifq_maxlen;
101 	int	ifq_drops;
102 	struct	mtx ifq_mtx;
103 };
104 
105 /*
106  * Structure defining a network interface.
107  *
108  * (Would like to call this struct ``if'', but C isn't PL/1.)
109  */
110 
111 /*
112  * NB: For FreeBSD, it is assumed that each NIC driver's softc starts with
113  * one of these structures, typically held within an arpcom structure.
114  *
115  *	struct <foo>_softc {
116  *		struct arpcom {
117  *			struct  ifnet ac_if;
118  *			...
119  *		} <arpcom> ;
120  *		...
121  *	};
122  *
123  * The assumption is used in a number of places, including many
124  * files in sys/net, device drivers, and sys/dev/mii.c:miibus_attach().
125  *
126  * Unfortunately devices' softc are opaque, so we depend on this layout
127  * to locate the struct ifnet from the softc in the generic code.
128  *
129  */
130 struct ifnet {
131 	void	*if_softc;		/* pointer to driver state */
132 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
133 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
134 	const char *if_dname;		/* driver name */
135 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
136 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
137 		/*
138 		 * if_addrhead is the list of all addresses associated to
139 		 * an interface.
140 		 * Some code in the kernel assumes that first element
141 		 * of the list has type AF_LINK, and contains sockaddr_dl
142 		 * addresses which store the link-level address and the name
143 		 * of the interface.
144 		 * However, access to the AF_LINK address through this
145 		 * field is deprecated. Use ifaddr_byindex() instead.
146 		 */
147 	struct	knlist if_klist;	/* events attached to this if */
148 	int	if_pcount;		/* number of promiscuous listeners */
149 	void	*if_carp;		/* carp (tbd) interface pointer */
150 	struct	bpf_if *if_bpf;		/* packet filter structure */
151 	u_short	if_index;		/* numeric abbreviation for this if  */
152 	short	if_timer;		/* time 'til if_watchdog called */
153 	u_short	if_nvlans;		/* number of active vlans */
154 	int	if_flags;		/* up/down, broadcast, etc. */
155 	int	if_capabilities;	/* interface capabilities */
156 	int	if_capenable;		/* enabled features */
157 	void	*if_linkmib;		/* link-type-specific MIB data */
158 	size_t	if_linkmiblen;		/* length of above data */
159 	struct	if_data if_data;
160 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
161 	int	if_amcount;		/* number of all-multicast requests */
162 /* procedure handles */
163 	int	(*if_output)		/* output routine (enqueue) */
164 		(struct ifnet *, struct mbuf *, struct sockaddr *,
165 		     struct rtentry *);
166 	void	(*if_input)		/* input routine (from h/w driver) */
167 		(struct ifnet *, struct mbuf *);
168 	void	(*if_start)		/* initiate output routine */
169 		(struct ifnet *);
170 	int	(*if_ioctl)		/* ioctl routine */
171 		(struct ifnet *, u_long, caddr_t);
172 	void	(*if_watchdog)		/* timer routine */
173 		(struct ifnet *);
174 	void	(*if_init)		/* Init routine */
175 		(void *);
176 	int	(*if_resolvemulti)	/* validate/resolve multicast */
177 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
178 	void	*if_spare1;		/* spare pointer 1 */
179 	void	*if_spare2;		/* spare pointer 2 */
180 	void	*if_spare3;		/* spare pointer 3 */
181 	u_int	if_spare_flags1;	/* spare flags 1 */
182 	u_int	if_spare_flags2;	/* spare flags 2 */
183 	struct  ifaltq if_snd;		/* output queue (includes altq) */
184 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
185 
186 	struct	lltable *lltables;	/* list of L3-L2 resolution tables */
187 
188 	struct	label *if_label;	/* interface MAC label */
189 
190 	/* these are only used by IPv6 */
191 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
192 	void	*if_afdata[AF_MAX];
193 	int	if_afdata_initialized;
194 	struct	mtx if_afdata_mtx;
195 	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
196 };
197 
198 typedef void if_init_f_t(void *);
199 
200 /*
201  * XXX These aliases are terribly dangerous because they could apply
202  * to anything.
203  */
204 #define	if_mtu		if_data.ifi_mtu
205 #define	if_type		if_data.ifi_type
206 #define if_physical	if_data.ifi_physical
207 #define	if_addrlen	if_data.ifi_addrlen
208 #define	if_hdrlen	if_data.ifi_hdrlen
209 #define	if_metric	if_data.ifi_metric
210 #define	if_link_state	if_data.ifi_link_state
211 #define	if_baudrate	if_data.ifi_baudrate
212 #define	if_hwassist	if_data.ifi_hwassist
213 #define	if_ipackets	if_data.ifi_ipackets
214 #define	if_ierrors	if_data.ifi_ierrors
215 #define	if_opackets	if_data.ifi_opackets
216 #define	if_oerrors	if_data.ifi_oerrors
217 #define	if_collisions	if_data.ifi_collisions
218 #define	if_ibytes	if_data.ifi_ibytes
219 #define	if_obytes	if_data.ifi_obytes
220 #define	if_imcasts	if_data.ifi_imcasts
221 #define	if_omcasts	if_data.ifi_omcasts
222 #define	if_iqdrops	if_data.ifi_iqdrops
223 #define	if_noproto	if_data.ifi_noproto
224 #define	if_lastchange	if_data.ifi_lastchange
225 #define if_recvquota	if_data.ifi_recvquota
226 #define	if_xmitquota	if_data.ifi_xmitquota
227 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
228 
229 /* for compatibility with other BSDs */
230 #define	if_addrlist	if_addrhead
231 #define	if_list		if_link
232 
233 /*
234  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
235  * are queues of messages stored on ifqueue structures
236  * (defined above).  Entries are added to and deleted from these structures
237  * by these macros, which should be called with ipl raised to splimp().
238  */
239 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
240 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
241 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
242 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
243 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
244 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
245 
246 #define	_IF_ENQUEUE(ifq, m) do { 				\
247 	(m)->m_nextpkt = NULL;					\
248 	if ((ifq)->ifq_tail == NULL) 				\
249 		(ifq)->ifq_head = m; 				\
250 	else 							\
251 		(ifq)->ifq_tail->m_nextpkt = m; 		\
252 	(ifq)->ifq_tail = m; 					\
253 	(ifq)->ifq_len++; 					\
254 } while (0)
255 
256 #define IF_ENQUEUE(ifq, m) do {					\
257 	IF_LOCK(ifq); 						\
258 	_IF_ENQUEUE(ifq, m); 					\
259 	IF_UNLOCK(ifq); 					\
260 } while (0)
261 
262 #define	_IF_PREPEND(ifq, m) do {				\
263 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
264 	if ((ifq)->ifq_tail == NULL) 				\
265 		(ifq)->ifq_tail = (m); 				\
266 	(ifq)->ifq_head = (m); 					\
267 	(ifq)->ifq_len++; 					\
268 } while (0)
269 
270 #define IF_PREPEND(ifq, m) do {		 			\
271 	IF_LOCK(ifq); 						\
272 	_IF_PREPEND(ifq, m); 					\
273 	IF_UNLOCK(ifq); 					\
274 } while (0)
275 
276 #define	_IF_DEQUEUE(ifq, m) do { 				\
277 	(m) = (ifq)->ifq_head; 					\
278 	if (m) { 						\
279 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
280 			(ifq)->ifq_tail = NULL; 		\
281 		(m)->m_nextpkt = NULL; 				\
282 		(ifq)->ifq_len--; 				\
283 	} 							\
284 } while (0)
285 
286 #define IF_DEQUEUE(ifq, m) do { 				\
287 	IF_LOCK(ifq); 						\
288 	_IF_DEQUEUE(ifq, m); 					\
289 	IF_UNLOCK(ifq); 					\
290 } while (0)
291 
292 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
293 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
294 
295 #define _IF_DRAIN(ifq) do { 					\
296 	struct mbuf *m; 					\
297 	for (;;) { 						\
298 		_IF_DEQUEUE(ifq, m); 				\
299 		if (m == NULL) 					\
300 			break; 					\
301 		m_freem(m); 					\
302 	} 							\
303 } while (0)
304 
305 #define IF_DRAIN(ifq) do {					\
306 	IF_LOCK(ifq);						\
307 	_IF_DRAIN(ifq);						\
308 	IF_UNLOCK(ifq);						\
309 } while(0)
310 
311 #ifdef _KERNEL
312 /* interface address change event */
313 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
314 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
315 /* new interface arrival event */
316 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
317 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
318 /* interface departure event */
319 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
320 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
321 
322 #define	IF_AFDATA_LOCK_INIT(ifp)	\
323     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
324 #define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
325 #define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
326 #define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
327 #define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
328 
329 #define	IFF_LOCKGIANT(ifp) do {						\
330 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
331 		mtx_lock(&Giant);					\
332 } while (0)
333 
334 #define	IFF_UNLOCKGIANT(ifp) do {					\
335 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
336 		mtx_unlock(&Giant);					\
337 } while (0)
338 
339 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
340 	    int adjust);
341 #define	IF_HANDOFF(ifq, m, ifp)			\
342 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
343 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
344 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
345 
346 void	if_start(struct ifnet *);
347 
348 #define	IFQ_ENQUEUE(ifq, m, err)					\
349 do {									\
350 	IF_LOCK(ifq);							\
351 	if (ALTQ_IS_ENABLED(ifq))					\
352 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
353 	else {								\
354 		if (_IF_QFULL(ifq)) {					\
355 			m_freem(m);					\
356 			(err) = ENOBUFS;				\
357 		} else {						\
358 			_IF_ENQUEUE(ifq, m);				\
359 			(err) = 0;					\
360 		}							\
361 	}								\
362 	if (err)							\
363 		(ifq)->ifq_drops++;					\
364 	IF_UNLOCK(ifq);							\
365 } while (0)
366 
367 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
368 do {									\
369 	if (TBR_IS_ENABLED(ifq))					\
370 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
371 	else if (ALTQ_IS_ENABLED(ifq))					\
372 		ALTQ_DEQUEUE(ifq, m);					\
373 	else								\
374 		_IF_DEQUEUE(ifq, m);					\
375 } while (0)
376 
377 #define	IFQ_DEQUEUE(ifq, m)						\
378 do {									\
379 	IF_LOCK(ifq);							\
380 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
381 	IF_UNLOCK(ifq);							\
382 } while (0)
383 
384 #define	IFQ_POLL_NOLOCK(ifq, m)						\
385 do {									\
386 	if (TBR_IS_ENABLED(ifq))					\
387 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
388 	else if (ALTQ_IS_ENABLED(ifq))					\
389 		ALTQ_POLL(ifq, m);					\
390 	else								\
391 		_IF_POLL(ifq, m);					\
392 } while (0)
393 
394 #define	IFQ_POLL(ifq, m)						\
395 do {									\
396 	IF_LOCK(ifq);							\
397 	IFQ_POLL_NOLOCK(ifq, m);					\
398 	IF_UNLOCK(ifq);							\
399 } while (0)
400 
401 #define	IFQ_PURGE_NOLOCK(ifq)						\
402 do {									\
403 	if (ALTQ_IS_ENABLED(ifq)) {					\
404 		ALTQ_PURGE(ifq);					\
405 	} else								\
406 		_IF_DRAIN(ifq);						\
407 } while (0)
408 
409 #define	IFQ_PURGE(ifq)							\
410 do {									\
411 	IF_LOCK(ifq);							\
412 	IFQ_PURGE_NOLOCK(ifq);						\
413 	IF_UNLOCK(ifq);							\
414 } while (0)
415 
416 #define	IFQ_SET_READY(ifq)						\
417 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
418 
419 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
420 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
421 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
422 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
423 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
424 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
425 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
426 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
427 
428 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
429 do {									\
430 	int len;							\
431 	short mflags;							\
432 									\
433 	len = (m)->m_pkthdr.len;					\
434 	mflags = (m)->m_flags;						\
435 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
436 	if ((err) == 0) {						\
437 		(ifp)->if_obytes += len + (adj);			\
438 		if (mflags & M_MCAST)					\
439 			(ifp)->if_omcasts++;				\
440 		if (((ifp)->if_flags & IFF_OACTIVE) == 0)		\
441 			if_start(ifp);					\
442 	}								\
443 } while (0)
444 
445 #define	IFQ_HANDOFF(ifp, m, err)					\
446 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
447 
448 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
449 do {									\
450 	(m) = (ifq)->ifq_drv_head;					\
451 	if (m) {							\
452 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
453 			(ifq)->ifq_drv_tail = NULL;			\
454 		(m)->m_nextpkt = NULL;					\
455 		(ifq)->ifq_drv_len--;					\
456 	} else {							\
457 		IFQ_LOCK(ifq);						\
458 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
459 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
460 			struct mbuf *m0;				\
461 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
462 			if (m0 == NULL)					\
463 				break;					\
464 			m0->m_nextpkt = NULL;				\
465 			if ((ifq)->ifq_drv_tail == NULL)		\
466 				(ifq)->ifq_drv_head = m0;		\
467 			else						\
468 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
469 			(ifq)->ifq_drv_tail = m0;			\
470 			(ifq)->ifq_drv_len++;				\
471 		}							\
472 		IFQ_UNLOCK(ifq);					\
473 	}								\
474 } while (0)
475 
476 #define	IFQ_DRV_PREPEND(ifq, m)						\
477 do {									\
478 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
479 	if ((ifq)->ifq_drv_tail == NULL)				\
480 		(ifq)->ifq_drv_tail = (m);				\
481 	(ifq)->ifq_drv_head = (m);					\
482 	(ifq)->ifq_drv_len++;						\
483 } while (0)
484 
485 #define	IFQ_DRV_IS_EMPTY(ifq)						\
486 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
487 
488 #define	IFQ_DRV_PURGE(ifq)						\
489 do {									\
490 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
491 	while((m = n) != NULL) {					\
492 		n = m->m_nextpkt;					\
493 		m_freem(m);						\
494 	}								\
495 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
496 	(ifq)->ifq_drv_len = 0;						\
497 	IFQ_PURGE(ifq);							\
498 } while (0)
499 
500 /*
501  * 72 was chosen below because it is the size of a TCP/IP
502  * header (40) + the minimum mss (32).
503  */
504 #define	IF_MINMTU	72
505 #define	IF_MAXMTU	65535
506 
507 #endif /* _KERNEL */
508 
509 /*
510  * The ifaddr structure contains information about one address
511  * of an interface.  They are maintained by the different address families,
512  * are allocated and attached when an address is set, and are linked
513  * together so all addresses for an interface can be located.
514  *
515  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
516  * chunk of malloc'ed memory, where we store the three addresses
517  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
518  */
519 struct ifaddr {
520 	struct	sockaddr *ifa_addr;	/* address of interface */
521 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
522 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
523 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
524 	struct	if_data if_data;	/* not all members are meaningful */
525 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
526 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
527 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
528 		(int, struct rtentry *, struct rt_addrinfo *);
529 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
530 	u_int	ifa_refcnt;		/* references to this structure */
531 	int	ifa_metric;		/* cost of going out this interface */
532 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
533 		(struct ifaddr *, struct sockaddr *);
534 	struct mtx ifa_mtx;
535 };
536 #define	IFA_ROUTE	RTF_UP		/* route installed */
537 
538 /* for compatibility with other BSDs */
539 #define	ifa_list	ifa_link
540 
541 #define	IFA_LOCK_INIT(ifa)	\
542     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
543 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
544 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
545 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
546 
547 /*
548  * The prefix structure contains information about one prefix
549  * of an interface.  They are maintained by the different address families,
550  * are allocated and attached when a prefix or an address is set,
551  * and are linked together so all prefixes for an interface can be located.
552  */
553 struct ifprefix {
554 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
555 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
556 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
557 	u_char	ifpr_plen;		/* prefix length in bits */
558 	u_char	ifpr_type;		/* protocol dependent prefix type */
559 };
560 
561 /*
562  * Multicast address structure.  This is analogous to the ifaddr
563  * structure except that it keeps track of multicast addresses.
564  * Also, the reference count here is a count of requests for this
565  * address, not a count of pointers to this structure.
566  */
567 struct ifmultiaddr {
568 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
569 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
570 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
571 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
572 	u_int	ifma_refcount;		/* reference count */
573 	void	*ifma_protospec;	/* protocol-specific state, if any */
574 };
575 
576 #ifdef _KERNEL
577 #define	IFAFREE(ifa)					\
578 	do {						\
579 		IFA_LOCK(ifa);				\
580 		KASSERT((ifa)->ifa_refcnt > 0,		\
581 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
582 		if (--(ifa)->ifa_refcnt == 0) {		\
583 			IFA_DESTROY(ifa);		\
584 			free(ifa, M_IFADDR);		\
585 		} else 					\
586 			IFA_UNLOCK(ifa);		\
587 	} while (0)
588 
589 #define IFAREF(ifa)					\
590 	do {						\
591 		IFA_LOCK(ifa);				\
592 		++(ifa)->ifa_refcnt;			\
593 		IFA_UNLOCK(ifa);			\
594 	} while (0)
595 
596 extern	struct mtx ifnet_lock;
597 #define	IFNET_LOCK_INIT() \
598     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
599 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
600 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
601 #define	IFNET_RLOCK()		IFNET_WLOCK()
602 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
603 
604 struct ifindex_entry {
605 	struct	ifnet *ife_ifnet;
606 	struct	ifaddr *ife_ifnet_addr;
607 	struct cdev *ife_dev;
608 };
609 
610 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
611 /*
612  * Given the index, ifaddr_byindex() returns the one and only
613  * link-level ifaddr for the interface. You are not supposed to use
614  * it to traverse the list of addresses associated to the interface.
615  */
616 #define ifaddr_byindex(idx)	ifindex_table[(idx)].ife_ifnet_addr
617 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
618 
619 extern	struct ifnethead ifnet;
620 extern	struct ifindex_entry *ifindex_table;
621 extern	int ifqmaxlen;
622 extern	struct ifnet *loif;	/* first loopback interface */
623 extern	int if_index;
624 
625 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
626 int	if_allmulti(struct ifnet *, int);
627 void	if_attach(struct ifnet *);
628 int	if_delmulti(struct ifnet *, struct sockaddr *);
629 void	if_detach(struct ifnet *);
630 void	if_down(struct ifnet *);
631 void	if_initname(struct ifnet *, const char *, int);
632 void	if_link_state_change(struct ifnet *, int);
633 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
634 int	if_setlladdr(struct ifnet *, const u_char *, int);
635 void	if_up(struct ifnet *);
636 /*void	ifinit(void);*/ /* declared in systm.h for main() */
637 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
638 int	ifpromisc(struct ifnet *, int);
639 struct	ifnet *ifunit(const char *);
640 
641 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
642 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
643 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
644 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
645 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
646 
647 struct	ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
648 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
649 
650 #define IF_LLADDR(ifp)							\
651     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
652 
653 #ifdef DEVICE_POLLING
654 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
655 
656 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
657 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
658 int    ether_poll_deregister(struct ifnet *ifp);
659 #endif /* DEVICE_POLLING */
660 
661 #endif /* _KERNEL */
662 
663 #endif /* !_NET_IF_VAR_H_ */
664