xref: /freebsd/sys/net/if_var.h (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
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 #if 1 /* ALTQ */
87 #include <altq/if_altq.h>
88 #endif
89 
90 TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
91 TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
92 TAILQ_HEAD(ifprefixhead, ifprefix);
93 TAILQ_HEAD(ifmultihead, ifmultiaddr);
94 
95 /*
96  * Structure defining a queue for a network interface.
97  */
98 struct	ifqueue {
99 	struct	mbuf *ifq_head;
100 	struct	mbuf *ifq_tail;
101 	int	ifq_len;
102 	int	ifq_maxlen;
103 	int	ifq_drops;
104 	struct	mtx ifq_mtx;
105 };
106 
107 /*
108  * Structure defining a network interface.
109  *
110  * (Would like to call this struct ``if'', but C isn't PL/1.)
111  */
112 
113 /*
114  * NB: For FreeBSD, it is assumed that each NIC driver's softc starts with
115  * one of these structures, typically held within an arpcom structure.
116  *
117  *	struct <foo>_softc {
118  *		struct arpcom {
119  *			struct  ifnet ac_if;
120  *			...
121  *		} <arpcom> ;
122  *		...
123  *	};
124  *
125  * The assumption is used in a number of places, including many
126  * files in sys/net, device drivers, and sys/dev/mii.c:miibus_attach().
127  *
128  * Unfortunately devices' softc are opaque, so we depend on this layout
129  * to locate the struct ifnet from the softc in the generic code.
130  *
131  */
132 struct ifnet {
133 	void	*if_softc;		/* pointer to driver state */
134 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
135 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
136 	const char *if_dname;		/* driver name */
137 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
138 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
139 		/*
140 		 * if_addrhead is the list of all addresses associated to
141 		 * an interface.
142 		 * Some code in the kernel assumes that first element
143 		 * of the list has type AF_LINK, and contains sockaddr_dl
144 		 * addresses which store the link-level address and the name
145 		 * of the interface.
146 		 * However, access to the AF_LINK address through this
147 		 * field is deprecated. Use ifaddr_byindex() instead.
148 		 */
149 	struct	klist if_klist;		/* events attached to this if */
150 	int	if_pcount;		/* number of promiscuous listeners */
151 	struct	bpf_if *if_bpf;		/* packet filter structure */
152 	u_short	if_index;		/* numeric abbreviation for this if  */
153 	short	if_timer;		/* time 'til if_watchdog called */
154 	u_short	if_nvlans;		/* number of active vlans */
155 	int	if_flags;		/* up/down, broadcast, etc. */
156 	int	if_capabilities;	/* interface capabilities */
157 	int	if_capenable;		/* enabled features */
158 	void	*if_linkmib;		/* link-type-specific MIB data */
159 	size_t	if_linkmiblen;		/* length of above data */
160 	struct	if_data if_data;
161 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
162 	int	if_amcount;		/* number of all-multicast requests */
163 /* procedure handles */
164 	int	(*if_output)		/* output routine (enqueue) */
165 		(struct ifnet *, struct mbuf *, struct sockaddr *,
166 		     struct rtentry *);
167 	void	(*if_input)		/* input routine (from h/w driver) */
168 		(struct ifnet *, struct mbuf *);
169 	void	(*if_start)		/* initiate output routine */
170 		(struct ifnet *);
171 	int	(*if_ioctl)		/* ioctl routine */
172 		(struct ifnet *, u_long, caddr_t);
173 	void	(*if_watchdog)		/* timer routine */
174 		(struct ifnet *);
175 	void	(*if_init)		/* Init routine */
176 		(void *);
177 	int	(*if_resolvemulti)	/* validate/resolve multicast */
178 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
179 #if 1 /* ALTQ */
180 	struct  ifaltq if_snd;		/* output queue (includes altq) */
181 #else
182 	struct	ifqueue if_snd;		/* output queue */
183 #endif
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 *)0)
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) == 0) 	\
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	IF_HANDOFF(ifq, m, ifp)			\
330 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
331 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
332 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
333 
334 void	if_start(struct ifnet *);
335 
336 static __inline int
337 if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp, int adjust)
338 {
339 	int active = 0;
340 
341 	IF_LOCK(ifq);
342 	if (_IF_QFULL(ifq)) {
343 		_IF_DROP(ifq);
344 		IF_UNLOCK(ifq);
345 		m_freem(m);
346 		return (0);
347 	}
348 	if (ifp != NULL) {
349 		ifp->if_obytes += m->m_pkthdr.len + adjust;
350 		if (m->m_flags & (M_BCAST|M_MCAST))
351 			ifp->if_omcasts++;
352 		active = ifp->if_flags & IFF_OACTIVE;
353 	}
354 	_IF_ENQUEUE(ifq, m);
355 	IF_UNLOCK(ifq);
356 	if (ifp != NULL && !active)
357 		if_start(ifp);
358 	return (1);
359 }
360 #if 1 /* ALTQ */
361 #define	IFQ_ENQUEUE(ifq, m, err)					\
362 do {									\
363 	IF_LOCK(ifq);							\
364 	if (ALTQ_IS_ENABLED(ifq))					\
365 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
366 	else {								\
367 		if (_IF_QFULL(ifq)) {					\
368 			m_freem(m);					\
369 			(err) = ENOBUFS;				\
370 		} else {						\
371 			_IF_ENQUEUE(ifq, m);				\
372 			(err) = 0;					\
373 		}							\
374 	}								\
375 	if (err)							\
376 		(ifq)->ifq_drops++;					\
377 	IF_UNLOCK(ifq);							\
378 } while (0)
379 
380 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
381 do {									\
382 	if (TBR_IS_ENABLED(ifq))					\
383 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
384 	else if (ALTQ_IS_ENABLED(ifq))					\
385 		ALTQ_DEQUEUE(ifq, m);					\
386 	else								\
387 		_IF_DEQUEUE(ifq, m);					\
388 } while (0)
389 
390 #define	IFQ_DEQUEUE(ifq, m)						\
391 do {									\
392 	IF_LOCK(ifq);							\
393 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
394 	IF_UNLOCK(ifq);							\
395 } while (0)
396 
397 #define	IFQ_POLL_NOLOCK(ifq, m)						\
398 do {									\
399 	if (TBR_IS_ENABLED(ifq))					\
400 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
401 	else if (ALTQ_IS_ENABLED(ifq))					\
402 		ALTQ_POLL(ifq, m);					\
403 	else								\
404 		_IF_POLL(ifq, m);					\
405 } while (0)
406 
407 #define	IFQ_POLL(ifq, m)						\
408 do {									\
409 	IF_LOCK(ifq);							\
410 	IFQ_POLL_NOLOCK(ifq, m);					\
411 	IF_UNLOCK(ifq);							\
412 } while (0)
413 
414 #define	IFQ_PURGE_NOLOCK(ifq)						\
415 do {									\
416 	if (ALTQ_IS_ENABLED(ifq)) {					\
417 		ALTQ_PURGE(ifq);					\
418 	} else								\
419 		_IF_DRAIN(ifq);						\
420 } while (0)
421 
422 #define	IFQ_PURGE(ifq)							\
423 do {									\
424 	IF_LOCK(ifq);							\
425 	IFQ_PURGE_NOLOCK(ifq);						\
426 	IF_UNLOCK(ifq);							\
427 } while (0)
428 
429 #define	IFQ_SET_READY(ifq)						\
430 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
431 
432 #else /* !ALTQ */
433 #define	IFQ_ENQUEUE(ifq, m, err)					\
434 do {									\
435 	IF_LOCK(ifq);							\
436 	if (_IF_QFULL(ifq)) {						\
437 		m_freem(m);						\
438 		(err) = ENOBUFS;					\
439 	} else {							\
440 		_IF_ENQUEUE(ifq, m);					\
441 		(err) = 0;						\
442 	}								\
443 	if (err)							\
444 		(ifq)->ifq_drops++;					\
445 	IF_UNLOCK(ifq);							\
446 } while (0)
447 
448 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)	_IF_DEQUEUE(ifq, m)
449 #define	IFQ_DEQUEUE(ifq, m)		IF_DEQUEUE(ifq, m)
450 #define	IFQ_POLL_NOLOCK(ifq, m)		_IF_POLL(ifq, m)
451 #define	IFQ_POLL(ifq, m)		IF_POLL(ifq, m)
452 #define	IFQ_PURGE_NOLOCK(ifq)		_IF_DRAIN(ifq)
453 #define	IFQ_PURGE(ifq)			IF_DRAIN(ifq)
454 
455 #define	IFQ_SET_READY(ifq)		/* nothing */
456 
457 #endif /* !ALTQ */
458 
459 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
460 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
461 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
462 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
463 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
464 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
465 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
466 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
467 
468 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
469 do {									\
470 	int len;							\
471 	short mflags;							\
472 									\
473 	len = (m)->m_pkthdr.len;					\
474 	mflags = (m)->m_flags;						\
475 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
476 	if ((err) == 0) {						\
477 		(ifp)->if_obytes += len + (adj);			\
478 		if (mflags & M_MCAST)					\
479 			(ifp)->if_omcasts++;				\
480 		if (((ifp)->if_flags & IFF_OACTIVE) == 0)		\
481 			if_start(ifp);					\
482 	}								\
483 } while (0)
484 
485 #define	IFQ_HANDOFF(ifp, m, err)					\
486 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
487 
488 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
489 do {									\
490 	(m) = (ifq)->ifq_drv_head;					\
491 	if (m) {							\
492 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
493 			(ifq)->ifq_drv_tail = NULL;			\
494 		(m)->m_nextpkt = NULL;					\
495 		(ifq)->ifq_drv_len--;					\
496 	} else {							\
497 		IFQ_LOCK(ifq);						\
498 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
499 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
500 			struct mbuf *m0;				\
501 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
502 			if (m0 == NULL)					\
503 				break;					\
504 			m0->m_nextpkt = NULL;				\
505 			if ((ifq)->ifq_drv_tail == NULL)		\
506 				(ifq)->ifq_drv_head = m0;		\
507 			else						\
508 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
509 			(ifq)->ifq_drv_tail = m0;			\
510 			(ifq)->ifq_drv_len++;				\
511 		}							\
512 		IFQ_UNLOCK(ifq);					\
513 	}								\
514 } while (0)
515 
516 #define	IFQ_DRV_PREPEND(ifq, m)						\
517 do {									\
518 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
519 	if ((ifq)->ifq_drv_tail == NULL)				\
520 		(ifq)->ifq_drv_tail = (m);				\
521 	(ifq)->ifq_drv_head = (m);					\
522 	(ifq)->ifq_drv_len++;						\
523 } while (0)
524 
525 #define	IFQ_DRV_IS_EMPTY(ifq)						\
526 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
527 
528 #define	IFQ_DRV_PURGE(ifq)						\
529 do {									\
530 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
531 	while((m = n) != NULL) {					\
532 		n = m->m_nextpkt;					\
533 		m_freem(m);						\
534 	}								\
535 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
536 	(ifq)->ifq_drv_len = 0;						\
537 	IFQ_PURGE(ifq);							\
538 } while (0)
539 
540 /*
541  * 72 was chosen below because it is the size of a TCP/IP
542  * header (40) + the minimum mss (32).
543  */
544 #define	IF_MINMTU	72
545 #define	IF_MAXMTU	65535
546 
547 #endif /* _KERNEL */
548 
549 /*
550  * The ifaddr structure contains information about one address
551  * of an interface.  They are maintained by the different address families,
552  * are allocated and attached when an address is set, and are linked
553  * together so all addresses for an interface can be located.
554  *
555  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
556  * chunk of malloc'ed memory, where we store the three addresses
557  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
558  */
559 struct ifaddr {
560 	struct	sockaddr *ifa_addr;	/* address of interface */
561 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
562 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
563 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
564 	struct	if_data if_data;	/* not all members are meaningful */
565 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
566 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
567 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
568 		(int, struct rtentry *, struct rt_addrinfo *);
569 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
570 	u_int	ifa_refcnt;		/* references to this structure */
571 	int	ifa_metric;		/* cost of going out this interface */
572 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
573 		(struct ifaddr *, struct sockaddr *);
574 	struct mtx ifa_mtx;
575 };
576 #define	IFA_ROUTE	RTF_UP		/* route installed */
577 
578 /* for compatibility with other BSDs */
579 #define	ifa_list	ifa_link
580 
581 #define	IFA_LOCK_INIT(ifa)	\
582     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
583 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
584 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
585 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
586 
587 /*
588  * The prefix structure contains information about one prefix
589  * of an interface.  They are maintained by the different address families,
590  * are allocated and attached when a prefix or an address is set,
591  * and are linked together so all prefixes for an interface can be located.
592  */
593 struct ifprefix {
594 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
595 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
596 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
597 	u_char	ifpr_plen;		/* prefix length in bits */
598 	u_char	ifpr_type;		/* protocol dependent prefix type */
599 };
600 
601 /*
602  * Multicast address structure.  This is analogous to the ifaddr
603  * structure except that it keeps track of multicast addresses.
604  * Also, the reference count here is a count of requests for this
605  * address, not a count of pointers to this structure.
606  */
607 struct ifmultiaddr {
608 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
609 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
610 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
611 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
612 	u_int	ifma_refcount;		/* reference count */
613 	void	*ifma_protospec;	/* protocol-specific state, if any */
614 };
615 
616 #ifdef _KERNEL
617 #define	IFAFREE(ifa)					\
618 	do {						\
619 		IFA_LOCK(ifa);				\
620 		KASSERT((ifa)->ifa_refcnt > 0,		\
621 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
622 		if (--(ifa)->ifa_refcnt == 0) {		\
623 			IFA_DESTROY(ifa);		\
624 			free(ifa, M_IFADDR);		\
625 		} else 					\
626 			IFA_UNLOCK(ifa);		\
627 	} while (0)
628 
629 #define IFAREF(ifa)					\
630 	do {						\
631 		IFA_LOCK(ifa);				\
632 		++(ifa)->ifa_refcnt;			\
633 		IFA_UNLOCK(ifa);			\
634 	} while (0)
635 
636 extern	struct mtx ifnet_lock;
637 #define	IFNET_LOCK_INIT() \
638     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
639 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
640 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
641 #define	IFNET_RLOCK()		IFNET_WLOCK()
642 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
643 
644 struct ifindex_entry {
645 	struct	ifnet *ife_ifnet;
646 	struct	ifaddr *ife_ifnet_addr;
647 	struct cdev *ife_dev;
648 };
649 
650 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
651 /*
652  * Given the index, ifaddr_byindex() returns the one and only
653  * link-level ifaddr for the interface. You are not supposed to use
654  * it to traverse the list of addresses associated to the interface.
655  */
656 #define ifaddr_byindex(idx)	ifindex_table[(idx)].ife_ifnet_addr
657 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
658 
659 extern	struct ifnethead ifnet;
660 extern	struct ifindex_entry *ifindex_table;
661 extern	int ifqmaxlen;
662 extern	struct ifnet *loif;	/* first loopback interface */
663 extern	int if_index;
664 
665 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
666 int	if_allmulti(struct ifnet *, int);
667 void	if_attach(struct ifnet *);
668 int	if_delmulti(struct ifnet *, struct sockaddr *);
669 void	if_detach(struct ifnet *);
670 void	if_down(struct ifnet *);
671 void	if_initname(struct ifnet *, const char *, int);
672 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
673 int	if_setlladdr(struct ifnet *, const u_char *, int);
674 void	if_up(struct ifnet *);
675 /*void	ifinit(void);*/ /* declared in systm.h for main() */
676 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
677 int	ifpromisc(struct ifnet *, int);
678 struct	ifnet *ifunit(const char *);
679 
680 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
681 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
682 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
683 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
684 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
685 
686 struct	ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
687 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
688 
689 #define IF_LLADDR(ifp)							\
690     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
691 
692 #ifdef DEVICE_POLLING
693 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
694 
695 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
696 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
697 int    ether_poll_deregister(struct ifnet *ifp);
698 #endif /* DEVICE_POLLING */
699 
700 #endif /* _KERNEL */
701 
702 #endif /* !_NET_IF_VAR_H_ */
703