xref: /freebsd/sys/net/if_var.h (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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 
83 #define	IF_DUNIT_NONE	-1
84 
85 #if 1 /* ALTQ */
86 #include <altq/if_altq.h>
87 #endif
88 
89 TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
90 TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
91 TAILQ_HEAD(ifprefixhead, ifprefix);
92 TAILQ_HEAD(ifmultihead, ifmultiaddr);
93 
94 /*
95  * Structure defining a queue for a network interface.
96  */
97 struct	ifqueue {
98 	struct	mbuf *ifq_head;
99 	struct	mbuf *ifq_tail;
100 	int	ifq_len;
101 	int	ifq_maxlen;
102 	int	ifq_drops;
103 	struct	mtx ifq_mtx;
104 };
105 
106 /*
107  * Structure defining a network interface.
108  *
109  * (Would like to call this struct ``if'', but C isn't PL/1.)
110  */
111 
112 /*
113  * NB: For FreeBSD, it is assumed that each NIC driver's softc starts with
114  * one of these structures, typically held within an arpcom structure.
115  *
116  *	struct <foo>_softc {
117  *		struct arpcom {
118  *			struct  ifnet ac_if;
119  *			...
120  *		} <arpcom> ;
121  *		...
122  *	};
123  *
124  * The assumption is used in a number of places, including many
125  * files in sys/net, device drivers, and sys/dev/mii.c:miibus_attach().
126  *
127  * Unfortunately devices' softc are opaque, so we depend on this layout
128  * to locate the struct ifnet from the softc in the generic code.
129  *
130  */
131 struct ifnet {
132 	void	*if_softc;		/* pointer to driver state */
133 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
134 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
135 	const char *if_dname;		/* driver name */
136 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
137 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
138 		/*
139 		 * if_addrhead is the list of all addresses associated to
140 		 * an interface.
141 		 * Some code in the kernel assumes that first element
142 		 * of the list has type AF_LINK, and contains sockaddr_dl
143 		 * addresses which store the link-level address and the name
144 		 * of the interface.
145 		 * However, access to the AF_LINK address through this
146 		 * field is deprecated. Use ifaddr_byindex() instead.
147 		 */
148 	struct	klist if_klist;		/* events attached to this if */
149 	int	if_pcount;		/* number of promiscuous listeners */
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 #if 1 /* ALTQ */
179 	struct  ifaltq if_snd;		/* output queue (includes altq) */
180 #else
181 	struct	ifqueue if_snd;		/* output queue */
182 #endif
183 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
184 
185 	struct	lltable *lltables;	/* list of L3-L2 resolution tables */
186 
187 	struct	label *if_label;	/* interface MAC label */
188 
189 	/* these are only used by IPv6 */
190 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
191 	void	*if_afdata[AF_MAX];
192 	int	if_afdata_initialized;
193 	struct	mtx if_afdata_mtx;
194 };
195 
196 typedef void if_init_f_t(void *);
197 
198 /*
199  * XXX These aliases are terribly dangerous because they could apply
200  * to anything.
201  */
202 #define	if_mtu		if_data.ifi_mtu
203 #define	if_type		if_data.ifi_type
204 #define if_physical	if_data.ifi_physical
205 #define	if_addrlen	if_data.ifi_addrlen
206 #define	if_hdrlen	if_data.ifi_hdrlen
207 #define	if_metric	if_data.ifi_metric
208 #define	if_link_state	if_data.ifi_link_state
209 #define	if_baudrate	if_data.ifi_baudrate
210 #define	if_hwassist	if_data.ifi_hwassist
211 #define	if_ipackets	if_data.ifi_ipackets
212 #define	if_ierrors	if_data.ifi_ierrors
213 #define	if_opackets	if_data.ifi_opackets
214 #define	if_oerrors	if_data.ifi_oerrors
215 #define	if_collisions	if_data.ifi_collisions
216 #define	if_ibytes	if_data.ifi_ibytes
217 #define	if_obytes	if_data.ifi_obytes
218 #define	if_imcasts	if_data.ifi_imcasts
219 #define	if_omcasts	if_data.ifi_omcasts
220 #define	if_iqdrops	if_data.ifi_iqdrops
221 #define	if_noproto	if_data.ifi_noproto
222 #define	if_lastchange	if_data.ifi_lastchange
223 #define if_recvquota	if_data.ifi_recvquota
224 #define	if_xmitquota	if_data.ifi_xmitquota
225 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)0)
226 
227 /* for compatibility with other BSDs */
228 #define	if_addrlist	if_addrhead
229 #define	if_list		if_link
230 
231 /*
232  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
233  * are queues of messages stored on ifqueue structures
234  * (defined above).  Entries are added to and deleted from these structures
235  * by these macros, which should be called with ipl raised to splimp().
236  */
237 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
238 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
239 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
240 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
241 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
242 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
243 
244 #define	_IF_ENQUEUE(ifq, m) do { 				\
245 	(m)->m_nextpkt = NULL;					\
246 	if ((ifq)->ifq_tail == NULL) 				\
247 		(ifq)->ifq_head = m; 				\
248 	else 							\
249 		(ifq)->ifq_tail->m_nextpkt = m; 		\
250 	(ifq)->ifq_tail = m; 					\
251 	(ifq)->ifq_len++; 					\
252 } while (0)
253 
254 #define IF_ENQUEUE(ifq, m) do {					\
255 	IF_LOCK(ifq); 						\
256 	_IF_ENQUEUE(ifq, m); 					\
257 	IF_UNLOCK(ifq); 					\
258 } while (0)
259 
260 #define	_IF_PREPEND(ifq, m) do {				\
261 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
262 	if ((ifq)->ifq_tail == NULL) 				\
263 		(ifq)->ifq_tail = (m); 				\
264 	(ifq)->ifq_head = (m); 					\
265 	(ifq)->ifq_len++; 					\
266 } while (0)
267 
268 #define IF_PREPEND(ifq, m) do {		 			\
269 	IF_LOCK(ifq); 						\
270 	_IF_PREPEND(ifq, m); 					\
271 	IF_UNLOCK(ifq); 					\
272 } while (0)
273 
274 #define	_IF_DEQUEUE(ifq, m) do { 				\
275 	(m) = (ifq)->ifq_head; 					\
276 	if (m) { 						\
277 		if (((ifq)->ifq_head = (m)->m_nextpkt) == 0) 	\
278 			(ifq)->ifq_tail = NULL; 		\
279 		(m)->m_nextpkt = NULL; 				\
280 		(ifq)->ifq_len--; 				\
281 	} 							\
282 } while (0)
283 
284 #define IF_DEQUEUE(ifq, m) do { 				\
285 	IF_LOCK(ifq); 						\
286 	_IF_DEQUEUE(ifq, m); 					\
287 	IF_UNLOCK(ifq); 					\
288 } while (0)
289 
290 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
291 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
292 
293 #define _IF_DRAIN(ifq) do { 					\
294 	struct mbuf *m; 					\
295 	for (;;) { 						\
296 		_IF_DEQUEUE(ifq, m); 				\
297 		if (m == NULL) 					\
298 			break; 					\
299 		m_freem(m); 					\
300 	} 							\
301 } while (0)
302 
303 #define IF_DRAIN(ifq) do {					\
304 	IF_LOCK(ifq);						\
305 	_IF_DRAIN(ifq);						\
306 	IF_UNLOCK(ifq);						\
307 } while(0)
308 
309 #ifdef _KERNEL
310 /* interface address change event */
311 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
312 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
313 /* new interface arrival event */
314 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
315 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
316 /* interface departure event */
317 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
318 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
319 
320 #define	IF_AFDATA_LOCK_INIT(ifp)	\
321     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
322 #define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
323 #define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
324 #define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
325 #define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
326 
327 #define	IF_HANDOFF(ifq, m, ifp)			\
328 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
329 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
330 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
331 
332 static __inline int
333 if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp, int adjust)
334 {
335 	int active = 0;
336 
337 	IF_LOCK(ifq);
338 	if (_IF_QFULL(ifq)) {
339 		_IF_DROP(ifq);
340 		IF_UNLOCK(ifq);
341 		m_freem(m);
342 		return (0);
343 	}
344 	if (ifp != NULL) {
345 		ifp->if_obytes += m->m_pkthdr.len + adjust;
346 		if (m->m_flags & (M_BCAST|M_MCAST))
347 			ifp->if_omcasts++;
348 		active = ifp->if_flags & IFF_OACTIVE;
349 	}
350 	_IF_ENQUEUE(ifq, m);
351 	IF_UNLOCK(ifq);
352 	if (ifp != NULL && !active)
353 		(*ifp->if_start)(ifp);
354 	return (1);
355 }
356 #if 1 /* ALTQ */
357 #define	IFQ_ENQUEUE(ifq, m, err)					\
358 do {									\
359 	IF_LOCK(ifq);							\
360 	if (ALTQ_IS_ENABLED(ifq))					\
361 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
362 	else {								\
363 		if (_IF_QFULL(ifq)) {					\
364 			m_freem(m);					\
365 			(err) = ENOBUFS;				\
366 		} else {						\
367 			_IF_ENQUEUE(ifq, m);				\
368 			(err) = 0;					\
369 		}							\
370 	}								\
371 	if (err)							\
372 		(ifq)->ifq_drops++;					\
373 	IF_UNLOCK(ifq);							\
374 } while (0)
375 
376 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
377 do {									\
378 	if (TBR_IS_ENABLED(ifq))					\
379 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
380 	else if (ALTQ_IS_ENABLED(ifq))					\
381 		ALTQ_DEQUEUE(ifq, m);					\
382 	else								\
383 		_IF_DEQUEUE(ifq, m);					\
384 } while (0)
385 
386 #define	IFQ_DEQUEUE(ifq, m)						\
387 do {									\
388 	IF_LOCK(ifq);							\
389 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
390 	IF_UNLOCK(ifq);							\
391 } while (0)
392 
393 #define	IFQ_POLL_NOLOCK(ifq, m)						\
394 do {									\
395 	if (TBR_IS_ENABLED(ifq))					\
396 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
397 	else if (ALTQ_IS_ENABLED(ifq))					\
398 		ALTQ_POLL(ifq, m);					\
399 	else								\
400 		_IF_POLL(ifq, m);					\
401 } while (0)
402 
403 #define	IFQ_POLL(ifq, m)						\
404 do {									\
405 	IF_LOCK(ifq);							\
406 	IFQ_POLL_NOLOCK(ifq, m);					\
407 	IF_UNLOCK(ifq);							\
408 } while (0)
409 
410 #define	IFQ_PURGE_NOLOCK(ifq)						\
411 do {									\
412 	if (ALTQ_IS_ENABLED(ifq)) {					\
413 		ALTQ_PURGE(ifq);					\
414 	} else								\
415 		_IF_DRAIN(ifq);						\
416 } while (0)
417 
418 #define	IFQ_PURGE(ifq)							\
419 do {									\
420 	IF_LOCK(ifq);							\
421 	IFQ_PURGE_NOLOCK(ifq);						\
422 	IF_UNLOCK(ifq);							\
423 } while (0)
424 
425 #define	IFQ_SET_READY(ifq)						\
426 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
427 
428 #else /* !ALTQ */
429 #define	IFQ_ENQUEUE(ifq, m, err)					\
430 do {									\
431 	IF_LOCK(ifq);							\
432 	if (_IF_QFULL(ifq)) {						\
433 		m_freem(m);						\
434 		(err) = ENOBUFS;					\
435 	} else {							\
436 		_IF_ENQUEUE(ifq, m);					\
437 		(err) = 0;						\
438 	}								\
439 	if (err)							\
440 		(ifq)->ifq_drops++;					\
441 	IF_UNLOCK(ifq);							\
442 } while (0)
443 
444 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)	_IF_DEQUEUE(ifq, m)
445 #define	IFQ_DEQUEUE(ifq, m)		IF_DEQUEUE(ifq, m)
446 #define	IFQ_POLL_NOLOCK(ifq, m)		_IF_POLL(ifq, m)
447 #define	IFQ_POLL(ifq, m)		IF_POLL(ifq, m)
448 #define	IFQ_PURGE_NOLOCK(ifq)		_IF_DRAIN(ifq)
449 #define	IFQ_PURGE(ifq)			IF_DRAIN(ifq)
450 
451 #define	IFQ_SET_READY(ifq)		/* nothing */
452 
453 #endif /* !ALTQ */
454 
455 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
456 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
457 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
458 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
459 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
460 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
461 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
462 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
463 
464 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
465 do {									\
466 	int len;							\
467 	short mflags;							\
468 									\
469 	len = (m)->m_pkthdr.len;					\
470 	mflags = (m)->m_flags;						\
471 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
472 	if ((err) == 0) {						\
473 		(ifp)->if_obytes += len + (adj);			\
474 		if (mflags & M_MCAST)					\
475 			(ifp)->if_omcasts++;				\
476 		if (((ifp)->if_flags & IFF_OACTIVE) == 0)		\
477 			(*(ifp)->if_start)(ifp);			\
478 	}								\
479 } while (0)
480 
481 #define	IFQ_HANDOFF(ifp, m, err)					\
482 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
483 
484 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
485 do {									\
486 	(m) = (ifq)->ifq_drv_head;					\
487 	if (m) {							\
488 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
489 			(ifq)->ifq_drv_tail = NULL;			\
490 		(m)->m_nextpkt = NULL;					\
491 		(ifq)->ifq_drv_len--;					\
492 	} else {							\
493 		IFQ_LOCK(ifq);						\
494 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
495 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
496 			struct mbuf *m0;				\
497 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
498 			if (m0 == NULL)					\
499 				break;					\
500 			m0->m_nextpkt = NULL;				\
501 			if ((ifq)->ifq_drv_tail == NULL)		\
502 				(ifq)->ifq_drv_head = m0;		\
503 			else						\
504 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
505 			(ifq)->ifq_drv_tail = m0;			\
506 			(ifq)->ifq_drv_len++;				\
507 		}							\
508 		IFQ_UNLOCK(ifq);					\
509 	}								\
510 } while (0)
511 
512 #define	IFQ_DRV_PREPEND(ifq, m)						\
513 do {									\
514 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
515 	if ((ifq)->ifq_tail == NULL)					\
516 		(ifq)->ifq_tail = (m);					\
517 	(ifq)->ifq_drv_head = (m);					\
518 	(ifq)->ifq_drv_len++;						\
519 } while (0)
520 
521 #define	IFQ_DRV_IS_EMPTY(ifq)						\
522 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
523 
524 #define	IFQ_DRV_PURGE(ifq)						\
525 do {									\
526 	struct mbuf *m = (ifq)->ifq_drv_head;				\
527 	while(m != NULL) {						\
528 		m = m->m_nextpkt;					\
529 		m_freem(m);						\
530 	}								\
531 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
532 	(ifq)->ifq_drv_len = 0;						\
533 	IFQ_PURGE(ifq);							\
534 } while (0)
535 
536 /*
537  * 72 was chosen below because it is the size of a TCP/IP
538  * header (40) + the minimum mss (32).
539  */
540 #define	IF_MINMTU	72
541 #define	IF_MAXMTU	65535
542 
543 #endif /* _KERNEL */
544 
545 /*
546  * The ifaddr structure contains information about one address
547  * of an interface.  They are maintained by the different address families,
548  * are allocated and attached when an address is set, and are linked
549  * together so all addresses for an interface can be located.
550  *
551  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
552  * chunk of malloc'ed memory, where we store the three addresses
553  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
554  */
555 struct ifaddr {
556 	struct	sockaddr *ifa_addr;	/* address of interface */
557 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
558 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
559 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
560 	struct	if_data if_data;	/* not all members are meaningful */
561 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
562 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
563 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
564 		(int, struct rtentry *, struct rt_addrinfo *);
565 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
566 	u_int	ifa_refcnt;		/* references to this structure */
567 	int	ifa_metric;		/* cost of going out this interface */
568 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
569 		(struct ifaddr *, struct sockaddr *);
570 	struct mtx ifa_mtx;
571 };
572 #define	IFA_ROUTE	RTF_UP		/* route installed */
573 
574 /* for compatibility with other BSDs */
575 #define	ifa_list	ifa_link
576 
577 #define	IFA_LOCK_INIT(ifa)	\
578     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
579 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
580 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
581 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
582 
583 /*
584  * The prefix structure contains information about one prefix
585  * of an interface.  They are maintained by the different address families,
586  * are allocated and attached when a prefix or an address is set,
587  * and are linked together so all prefixes for an interface can be located.
588  */
589 struct ifprefix {
590 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
591 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
592 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
593 	u_char	ifpr_plen;		/* prefix length in bits */
594 	u_char	ifpr_type;		/* protocol dependent prefix type */
595 };
596 
597 /*
598  * Multicast address structure.  This is analogous to the ifaddr
599  * structure except that it keeps track of multicast addresses.
600  * Also, the reference count here is a count of requests for this
601  * address, not a count of pointers to this structure.
602  */
603 struct ifmultiaddr {
604 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
605 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
606 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
607 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
608 	u_int	ifma_refcount;		/* reference count */
609 	void	*ifma_protospec;	/* protocol-specific state, if any */
610 };
611 
612 #ifdef _KERNEL
613 #define	IFAFREE(ifa)					\
614 	do {						\
615 		IFA_LOCK(ifa);				\
616 		KASSERT((ifa)->ifa_refcnt > 0,		\
617 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
618 		if (--(ifa)->ifa_refcnt == 0) {		\
619 			IFA_DESTROY(ifa);		\
620 			free(ifa, M_IFADDR);		\
621 		} else 					\
622 			IFA_UNLOCK(ifa);		\
623 	} while (0)
624 
625 #define IFAREF(ifa)					\
626 	do {						\
627 		IFA_LOCK(ifa);				\
628 		++(ifa)->ifa_refcnt;			\
629 		IFA_UNLOCK(ifa);			\
630 	} while (0)
631 
632 extern	struct mtx ifnet_lock;
633 #define	IFNET_LOCK_INIT() \
634     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
635 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
636 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
637 #define	IFNET_RLOCK()		IFNET_WLOCK()
638 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
639 
640 struct ifindex_entry {
641 	struct	ifnet *ife_ifnet;
642 	struct	ifaddr *ife_ifnet_addr;
643 	struct cdev *ife_dev;
644 };
645 
646 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
647 /*
648  * Given the index, ifaddr_byindex() returns the one and only
649  * link-level ifaddr for the interface. You are not supposed to use
650  * it to traverse the list of addresses associated to the interface.
651  */
652 #define ifaddr_byindex(idx)	ifindex_table[(idx)].ife_ifnet_addr
653 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
654 
655 extern	struct ifnethead ifnet;
656 extern	struct ifindex_entry *ifindex_table;
657 extern	int ifqmaxlen;
658 extern	struct ifnet *loif;	/* first loopback interface */
659 extern	int if_index;
660 
661 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
662 int	if_allmulti(struct ifnet *, int);
663 void	if_attach(struct ifnet *);
664 int	if_delmulti(struct ifnet *, struct sockaddr *);
665 void	if_detach(struct ifnet *);
666 void	if_down(struct ifnet *);
667 void	if_initname(struct ifnet *, const char *, int);
668 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
669 int	if_setlladdr(struct ifnet *, const u_char *, int);
670 void	if_up(struct ifnet *);
671 /*void	ifinit(void);*/ /* declared in systm.h for main() */
672 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
673 int	ifpromisc(struct ifnet *, int);
674 struct	ifnet *ifunit(const char *);
675 
676 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
677 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
678 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
679 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
680 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
681 
682 struct	ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
683 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
684 
685 #define IF_LLADDR(ifp)							\
686     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
687 
688 #ifdef DEVICE_POLLING
689 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
690 
691 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
692 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
693 int    ether_poll_deregister(struct ifnet *ifp);
694 #endif /* DEVICE_POLLING */
695 
696 #endif /* _KERNEL */
697 
698 #endif /* !_NET_IF_VAR_H_ */
699