xref: /freebsd/sys/net/if_var.h (revision 7562eaabc01a48e6b11d5b558c41e3b92dae5c2d)
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	knlist if_klist;	/* events attached to this if */
150 	int	if_pcount;		/* number of promiscuous listeners */
151 	void	*if_carp;		/* carp (tbd) interface pointer */
152 	struct	bpf_if *if_bpf;		/* packet filter structure */
153 	u_short	if_index;		/* numeric abbreviation for this if  */
154 	short	if_timer;		/* time 'til if_watchdog called */
155 	u_short	if_nvlans;		/* number of active vlans */
156 	int	if_flags;		/* up/down, broadcast, etc. */
157 	int	if_capabilities;	/* interface capabilities */
158 	int	if_capenable;		/* enabled features */
159 	void	*if_linkmib;		/* link-type-specific MIB data */
160 	size_t	if_linkmiblen;		/* length of above data */
161 	struct	if_data if_data;
162 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
163 	int	if_amcount;		/* number of all-multicast requests */
164 /* procedure handles */
165 	int	(*if_output)		/* output routine (enqueue) */
166 		(struct ifnet *, struct mbuf *, struct sockaddr *,
167 		     struct rtentry *);
168 	void	(*if_input)		/* input routine (from h/w driver) */
169 		(struct ifnet *, struct mbuf *);
170 	void	(*if_start)		/* initiate output routine */
171 		(struct ifnet *);
172 	int	(*if_ioctl)		/* ioctl routine */
173 		(struct ifnet *, u_long, caddr_t);
174 	void	(*if_watchdog)		/* timer routine */
175 		(struct ifnet *);
176 	void	(*if_init)		/* Init routine */
177 		(void *);
178 	int	(*if_resolvemulti)	/* validate/resolve multicast */
179 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
180 	void	*if_spare1;		/* spare pointer 1 */
181 	void	*if_spare2;		/* spare pointer 2 */
182 	void	*if_spare3;		/* spare pointer 3 */
183 	u_int	if_spare_flags1;	/* spare flags 1 */
184 	u_int	if_spare_flags2;	/* spare flags 2 */
185 #if 1 /* ALTQ */
186 	struct  ifaltq if_snd;		/* output queue (includes altq) */
187 #else
188 	struct	ifqueue if_snd;		/* output queue */
189 #endif
190 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
191 
192 	struct	lltable *lltables;	/* list of L3-L2 resolution tables */
193 
194 	struct	label *if_label;	/* interface MAC label */
195 
196 	/* these are only used by IPv6 */
197 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
198 	void	*if_afdata[AF_MAX];
199 	int	if_afdata_initialized;
200 	struct	mtx if_afdata_mtx;
201 	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
202 };
203 
204 typedef void if_init_f_t(void *);
205 
206 /*
207  * XXX These aliases are terribly dangerous because they could apply
208  * to anything.
209  */
210 #define	if_mtu		if_data.ifi_mtu
211 #define	if_type		if_data.ifi_type
212 #define if_physical	if_data.ifi_physical
213 #define	if_addrlen	if_data.ifi_addrlen
214 #define	if_hdrlen	if_data.ifi_hdrlen
215 #define	if_metric	if_data.ifi_metric
216 #define	if_link_state	if_data.ifi_link_state
217 #define	if_baudrate	if_data.ifi_baudrate
218 #define	if_hwassist	if_data.ifi_hwassist
219 #define	if_ipackets	if_data.ifi_ipackets
220 #define	if_ierrors	if_data.ifi_ierrors
221 #define	if_opackets	if_data.ifi_opackets
222 #define	if_oerrors	if_data.ifi_oerrors
223 #define	if_collisions	if_data.ifi_collisions
224 #define	if_ibytes	if_data.ifi_ibytes
225 #define	if_obytes	if_data.ifi_obytes
226 #define	if_imcasts	if_data.ifi_imcasts
227 #define	if_omcasts	if_data.ifi_omcasts
228 #define	if_iqdrops	if_data.ifi_iqdrops
229 #define	if_noproto	if_data.ifi_noproto
230 #define	if_lastchange	if_data.ifi_lastchange
231 #define if_recvquota	if_data.ifi_recvquota
232 #define	if_xmitquota	if_data.ifi_xmitquota
233 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
234 
235 /* for compatibility with other BSDs */
236 #define	if_addrlist	if_addrhead
237 #define	if_list		if_link
238 
239 /*
240  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
241  * are queues of messages stored on ifqueue structures
242  * (defined above).  Entries are added to and deleted from these structures
243  * by these macros, which should be called with ipl raised to splimp().
244  */
245 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
246 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
247 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
248 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
249 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
250 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
251 
252 #define	_IF_ENQUEUE(ifq, m) do { 				\
253 	(m)->m_nextpkt = NULL;					\
254 	if ((ifq)->ifq_tail == NULL) 				\
255 		(ifq)->ifq_head = m; 				\
256 	else 							\
257 		(ifq)->ifq_tail->m_nextpkt = m; 		\
258 	(ifq)->ifq_tail = m; 					\
259 	(ifq)->ifq_len++; 					\
260 } while (0)
261 
262 #define IF_ENQUEUE(ifq, m) do {					\
263 	IF_LOCK(ifq); 						\
264 	_IF_ENQUEUE(ifq, m); 					\
265 	IF_UNLOCK(ifq); 					\
266 } while (0)
267 
268 #define	_IF_PREPEND(ifq, m) do {				\
269 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
270 	if ((ifq)->ifq_tail == NULL) 				\
271 		(ifq)->ifq_tail = (m); 				\
272 	(ifq)->ifq_head = (m); 					\
273 	(ifq)->ifq_len++; 					\
274 } while (0)
275 
276 #define IF_PREPEND(ifq, m) do {		 			\
277 	IF_LOCK(ifq); 						\
278 	_IF_PREPEND(ifq, m); 					\
279 	IF_UNLOCK(ifq); 					\
280 } while (0)
281 
282 #define	_IF_DEQUEUE(ifq, m) do { 				\
283 	(m) = (ifq)->ifq_head; 					\
284 	if (m) { 						\
285 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
286 			(ifq)->ifq_tail = NULL; 		\
287 		(m)->m_nextpkt = NULL; 				\
288 		(ifq)->ifq_len--; 				\
289 	} 							\
290 } while (0)
291 
292 #define IF_DEQUEUE(ifq, m) do { 				\
293 	IF_LOCK(ifq); 						\
294 	_IF_DEQUEUE(ifq, m); 					\
295 	IF_UNLOCK(ifq); 					\
296 } while (0)
297 
298 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
299 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
300 
301 #define _IF_DRAIN(ifq) do { 					\
302 	struct mbuf *m; 					\
303 	for (;;) { 						\
304 		_IF_DEQUEUE(ifq, m); 				\
305 		if (m == NULL) 					\
306 			break; 					\
307 		m_freem(m); 					\
308 	} 							\
309 } while (0)
310 
311 #define IF_DRAIN(ifq) do {					\
312 	IF_LOCK(ifq);						\
313 	_IF_DRAIN(ifq);						\
314 	IF_UNLOCK(ifq);						\
315 } while(0)
316 
317 #ifdef _KERNEL
318 /* interface address change event */
319 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
320 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
321 /* new interface arrival event */
322 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
323 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
324 /* interface departure event */
325 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
326 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
327 
328 #define	IF_AFDATA_LOCK_INIT(ifp)	\
329     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
330 #define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
331 #define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
332 #define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
333 #define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
334 
335 #define	IFF_LOCKGIANT(ifp) do {						\
336 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
337 		mtx_lock(&Giant);					\
338 } while (0)
339 
340 #define	IFF_UNLOCKGIANT(ifp) do {					\
341 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
342 		mtx_unlock(&Giant);					\
343 } while (0)
344 
345 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
346 	    int adjust);
347 #define	IF_HANDOFF(ifq, m, ifp)			\
348 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
349 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
350 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
351 
352 void	if_start(struct ifnet *);
353 
354 #if 1 /* ALTQ */
355 #define	IFQ_ENQUEUE(ifq, m, err)					\
356 do {									\
357 	IF_LOCK(ifq);							\
358 	if (ALTQ_IS_ENABLED(ifq))					\
359 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
360 	else {								\
361 		if (_IF_QFULL(ifq)) {					\
362 			m_freem(m);					\
363 			(err) = ENOBUFS;				\
364 		} else {						\
365 			_IF_ENQUEUE(ifq, m);				\
366 			(err) = 0;					\
367 		}							\
368 	}								\
369 	if (err)							\
370 		(ifq)->ifq_drops++;					\
371 	IF_UNLOCK(ifq);							\
372 } while (0)
373 
374 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
375 do {									\
376 	if (TBR_IS_ENABLED(ifq))					\
377 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
378 	else if (ALTQ_IS_ENABLED(ifq))					\
379 		ALTQ_DEQUEUE(ifq, m);					\
380 	else								\
381 		_IF_DEQUEUE(ifq, m);					\
382 } while (0)
383 
384 #define	IFQ_DEQUEUE(ifq, m)						\
385 do {									\
386 	IF_LOCK(ifq);							\
387 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
388 	IF_UNLOCK(ifq);							\
389 } while (0)
390 
391 #define	IFQ_POLL_NOLOCK(ifq, m)						\
392 do {									\
393 	if (TBR_IS_ENABLED(ifq))					\
394 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
395 	else if (ALTQ_IS_ENABLED(ifq))					\
396 		ALTQ_POLL(ifq, m);					\
397 	else								\
398 		_IF_POLL(ifq, m);					\
399 } while (0)
400 
401 #define	IFQ_POLL(ifq, m)						\
402 do {									\
403 	IF_LOCK(ifq);							\
404 	IFQ_POLL_NOLOCK(ifq, m);					\
405 	IF_UNLOCK(ifq);							\
406 } while (0)
407 
408 #define	IFQ_PURGE_NOLOCK(ifq)						\
409 do {									\
410 	if (ALTQ_IS_ENABLED(ifq)) {					\
411 		ALTQ_PURGE(ifq);					\
412 	} else								\
413 		_IF_DRAIN(ifq);						\
414 } while (0)
415 
416 #define	IFQ_PURGE(ifq)							\
417 do {									\
418 	IF_LOCK(ifq);							\
419 	IFQ_PURGE_NOLOCK(ifq);						\
420 	IF_UNLOCK(ifq);							\
421 } while (0)
422 
423 #define	IFQ_SET_READY(ifq)						\
424 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
425 
426 #else /* !ALTQ */
427 #define	IFQ_ENQUEUE(ifq, m, err)					\
428 do {									\
429 	IF_LOCK(ifq);							\
430 	if (_IF_QFULL(ifq)) {						\
431 		m_freem(m);						\
432 		(err) = ENOBUFS;					\
433 	} else {							\
434 		_IF_ENQUEUE(ifq, m);					\
435 		(err) = 0;						\
436 	}								\
437 	if (err)							\
438 		(ifq)->ifq_drops++;					\
439 	IF_UNLOCK(ifq);							\
440 } while (0)
441 
442 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)	_IF_DEQUEUE(ifq, m)
443 #define	IFQ_DEQUEUE(ifq, m)		IF_DEQUEUE(ifq, m)
444 #define	IFQ_POLL_NOLOCK(ifq, m)		_IF_POLL(ifq, m)
445 #define	IFQ_POLL(ifq, m)		IF_POLL(ifq, m)
446 #define	IFQ_PURGE_NOLOCK(ifq)		_IF_DRAIN(ifq)
447 #define	IFQ_PURGE(ifq)			IF_DRAIN(ifq)
448 
449 #define	IFQ_SET_READY(ifq)		/* nothing */
450 
451 #endif /* !ALTQ */
452 
453 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
454 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
455 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
456 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
457 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
458 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
459 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
460 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
461 
462 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
463 do {									\
464 	int len;							\
465 	short mflags;							\
466 									\
467 	len = (m)->m_pkthdr.len;					\
468 	mflags = (m)->m_flags;						\
469 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
470 	if ((err) == 0) {						\
471 		(ifp)->if_obytes += len + (adj);			\
472 		if (mflags & M_MCAST)					\
473 			(ifp)->if_omcasts++;				\
474 		if (((ifp)->if_flags & IFF_OACTIVE) == 0)		\
475 			if_start(ifp);					\
476 	}								\
477 } while (0)
478 
479 #define	IFQ_HANDOFF(ifp, m, err)					\
480 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
481 
482 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
483 do {									\
484 	(m) = (ifq)->ifq_drv_head;					\
485 	if (m) {							\
486 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
487 			(ifq)->ifq_drv_tail = NULL;			\
488 		(m)->m_nextpkt = NULL;					\
489 		(ifq)->ifq_drv_len--;					\
490 	} else {							\
491 		IFQ_LOCK(ifq);						\
492 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
493 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
494 			struct mbuf *m0;				\
495 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
496 			if (m0 == NULL)					\
497 				break;					\
498 			m0->m_nextpkt = NULL;				\
499 			if ((ifq)->ifq_drv_tail == NULL)		\
500 				(ifq)->ifq_drv_head = m0;		\
501 			else						\
502 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
503 			(ifq)->ifq_drv_tail = m0;			\
504 			(ifq)->ifq_drv_len++;				\
505 		}							\
506 		IFQ_UNLOCK(ifq);					\
507 	}								\
508 } while (0)
509 
510 #define	IFQ_DRV_PREPEND(ifq, m)						\
511 do {									\
512 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
513 	if ((ifq)->ifq_drv_tail == NULL)				\
514 		(ifq)->ifq_drv_tail = (m);				\
515 	(ifq)->ifq_drv_head = (m);					\
516 	(ifq)->ifq_drv_len++;						\
517 } while (0)
518 
519 #define	IFQ_DRV_IS_EMPTY(ifq)						\
520 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
521 
522 #define	IFQ_DRV_PURGE(ifq)						\
523 do {									\
524 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
525 	while((m = n) != NULL) {					\
526 		n = m->m_nextpkt;					\
527 		m_freem(m);						\
528 	}								\
529 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
530 	(ifq)->ifq_drv_len = 0;						\
531 	IFQ_PURGE(ifq);							\
532 } while (0)
533 
534 /*
535  * 72 was chosen below because it is the size of a TCP/IP
536  * header (40) + the minimum mss (32).
537  */
538 #define	IF_MINMTU	72
539 #define	IF_MAXMTU	65535
540 
541 #endif /* _KERNEL */
542 
543 /*
544  * The ifaddr structure contains information about one address
545  * of an interface.  They are maintained by the different address families,
546  * are allocated and attached when an address is set, and are linked
547  * together so all addresses for an interface can be located.
548  *
549  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
550  * chunk of malloc'ed memory, where we store the three addresses
551  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
552  */
553 struct ifaddr {
554 	struct	sockaddr *ifa_addr;	/* address of interface */
555 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
556 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
557 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
558 	struct	if_data if_data;	/* not all members are meaningful */
559 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
560 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
561 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
562 		(int, struct rtentry *, struct rt_addrinfo *);
563 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
564 	u_int	ifa_refcnt;		/* references to this structure */
565 	int	ifa_metric;		/* cost of going out this interface */
566 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
567 		(struct ifaddr *, struct sockaddr *);
568 	struct mtx ifa_mtx;
569 };
570 #define	IFA_ROUTE	RTF_UP		/* route installed */
571 
572 /* for compatibility with other BSDs */
573 #define	ifa_list	ifa_link
574 
575 #define	IFA_LOCK_INIT(ifa)	\
576     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
577 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
578 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
579 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
580 
581 /*
582  * The prefix structure contains information about one prefix
583  * of an interface.  They are maintained by the different address families,
584  * are allocated and attached when a prefix or an address is set,
585  * and are linked together so all prefixes for an interface can be located.
586  */
587 struct ifprefix {
588 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
589 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
590 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
591 	u_char	ifpr_plen;		/* prefix length in bits */
592 	u_char	ifpr_type;		/* protocol dependent prefix type */
593 };
594 
595 /*
596  * Multicast address structure.  This is analogous to the ifaddr
597  * structure except that it keeps track of multicast addresses.
598  * Also, the reference count here is a count of requests for this
599  * address, not a count of pointers to this structure.
600  */
601 struct ifmultiaddr {
602 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
603 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
604 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
605 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
606 	u_int	ifma_refcount;		/* reference count */
607 	void	*ifma_protospec;	/* protocol-specific state, if any */
608 };
609 
610 #ifdef _KERNEL
611 #define	IFAFREE(ifa)					\
612 	do {						\
613 		IFA_LOCK(ifa);				\
614 		KASSERT((ifa)->ifa_refcnt > 0,		\
615 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
616 		if (--(ifa)->ifa_refcnt == 0) {		\
617 			IFA_DESTROY(ifa);		\
618 			free(ifa, M_IFADDR);		\
619 		} else 					\
620 			IFA_UNLOCK(ifa);		\
621 	} while (0)
622 
623 #define IFAREF(ifa)					\
624 	do {						\
625 		IFA_LOCK(ifa);				\
626 		++(ifa)->ifa_refcnt;			\
627 		IFA_UNLOCK(ifa);			\
628 	} while (0)
629 
630 extern	struct mtx ifnet_lock;
631 #define	IFNET_LOCK_INIT() \
632     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
633 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
634 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
635 #define	IFNET_RLOCK()		IFNET_WLOCK()
636 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
637 
638 struct ifindex_entry {
639 	struct	ifnet *ife_ifnet;
640 	struct	ifaddr *ife_ifnet_addr;
641 	struct cdev *ife_dev;
642 };
643 
644 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
645 /*
646  * Given the index, ifaddr_byindex() returns the one and only
647  * link-level ifaddr for the interface. You are not supposed to use
648  * it to traverse the list of addresses associated to the interface.
649  */
650 #define ifaddr_byindex(idx)	ifindex_table[(idx)].ife_ifnet_addr
651 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
652 
653 extern	struct ifnethead ifnet;
654 extern	struct ifindex_entry *ifindex_table;
655 extern	int ifqmaxlen;
656 extern	struct ifnet *loif;	/* first loopback interface */
657 extern	int if_index;
658 
659 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
660 int	if_allmulti(struct ifnet *, int);
661 void	if_attach(struct ifnet *);
662 int	if_delmulti(struct ifnet *, struct sockaddr *);
663 void	if_detach(struct ifnet *);
664 void	if_down(struct ifnet *);
665 void	if_initname(struct ifnet *, const char *, int);
666 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
667 int	if_setlladdr(struct ifnet *, const u_char *, int);
668 void	if_up(struct ifnet *);
669 /*void	ifinit(void);*/ /* declared in systm.h for main() */
670 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
671 int	ifpromisc(struct ifnet *, int);
672 struct	ifnet *ifunit(const char *);
673 
674 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
675 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
676 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
677 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
678 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
679 
680 struct	ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
681 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
682 
683 #define IF_LLADDR(ifp)							\
684     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
685 
686 #ifdef DEVICE_POLLING
687 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
688 
689 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
690 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
691 int    ether_poll_deregister(struct ifnet *ifp);
692 #endif /* DEVICE_POLLING */
693 
694 #endif /* _KERNEL */
695 
696 #endif /* !_NET_IF_VAR_H_ */
697