xref: /freebsd/sys/net/if_var.h (revision ceaec73d406831b1251babb61675df0a1aa54a31)
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 struct	carp_if;
72 #endif
73 
74 #include <sys/queue.h>		/* get TAILQ macros */
75 
76 #ifdef _KERNEL
77 #include <sys/mbuf.h>
78 #include <sys/eventhandler.h>
79 #endif /* _KERNEL */
80 #include <sys/lock.h>		/* XXX */
81 #include <sys/mutex.h>		/* XXX */
82 #include <sys/event.h>		/* XXX */
83 #include <sys/_task.h>
84 
85 #define	IF_DUNIT_NONE	-1
86 
87 #include <altq/if_altq.h>
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	knlist if_klist;	/* events attached to this if */
149 	int	if_pcount;		/* number of promiscuous listeners */
150 	struct	carp_if *if_carp;	/* carp interface structure */
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 	void	*if_spare1;		/* spare pointer 1 */
180 	void	*if_spare2;		/* spare pointer 2 */
181 	void	*if_spare3;		/* spare pointer 3 */
182 	u_int	if_spare_flags1;	/* spare flags 1 */
183 	u_int	if_spare_flags2;	/* spare flags 2 */
184 	struct  ifaltq if_snd;		/* output queue (includes altq) */
185 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
186 
187 	struct	lltable *lltables;	/* list of L3-L2 resolution tables */
188 
189 	struct	label *if_label;	/* interface MAC label */
190 
191 	/* these are only used by IPv6 */
192 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
193 	void	*if_afdata[AF_MAX];
194 	int	if_afdata_initialized;
195 	struct	mtx if_afdata_mtx;
196 	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
197 };
198 
199 typedef void if_init_f_t(void *);
200 
201 /*
202  * XXX These aliases are terribly dangerous because they could apply
203  * to anything.
204  */
205 #define	if_mtu		if_data.ifi_mtu
206 #define	if_type		if_data.ifi_type
207 #define if_physical	if_data.ifi_physical
208 #define	if_addrlen	if_data.ifi_addrlen
209 #define	if_hdrlen	if_data.ifi_hdrlen
210 #define	if_metric	if_data.ifi_metric
211 #define	if_link_state	if_data.ifi_link_state
212 #define	if_baudrate	if_data.ifi_baudrate
213 #define	if_hwassist	if_data.ifi_hwassist
214 #define	if_ipackets	if_data.ifi_ipackets
215 #define	if_ierrors	if_data.ifi_ierrors
216 #define	if_opackets	if_data.ifi_opackets
217 #define	if_oerrors	if_data.ifi_oerrors
218 #define	if_collisions	if_data.ifi_collisions
219 #define	if_ibytes	if_data.ifi_ibytes
220 #define	if_obytes	if_data.ifi_obytes
221 #define	if_imcasts	if_data.ifi_imcasts
222 #define	if_omcasts	if_data.ifi_omcasts
223 #define	if_iqdrops	if_data.ifi_iqdrops
224 #define	if_noproto	if_data.ifi_noproto
225 #define	if_lastchange	if_data.ifi_lastchange
226 #define if_recvquota	if_data.ifi_recvquota
227 #define	if_xmitquota	if_data.ifi_xmitquota
228 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
229 
230 /* for compatibility with other BSDs */
231 #define	if_addrlist	if_addrhead
232 #define	if_list		if_link
233 
234 /*
235  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
236  * are queues of messages stored on ifqueue structures
237  * (defined above).  Entries are added to and deleted from these structures
238  * by these macros, which should be called with ipl raised to splimp().
239  */
240 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
241 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
242 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
243 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
244 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
245 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
246 
247 #define	_IF_ENQUEUE(ifq, m) do { 				\
248 	(m)->m_nextpkt = NULL;					\
249 	if ((ifq)->ifq_tail == NULL) 				\
250 		(ifq)->ifq_head = m; 				\
251 	else 							\
252 		(ifq)->ifq_tail->m_nextpkt = m; 		\
253 	(ifq)->ifq_tail = m; 					\
254 	(ifq)->ifq_len++; 					\
255 } while (0)
256 
257 #define IF_ENQUEUE(ifq, m) do {					\
258 	IF_LOCK(ifq); 						\
259 	_IF_ENQUEUE(ifq, m); 					\
260 	IF_UNLOCK(ifq); 					\
261 } while (0)
262 
263 #define	_IF_PREPEND(ifq, m) do {				\
264 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
265 	if ((ifq)->ifq_tail == NULL) 				\
266 		(ifq)->ifq_tail = (m); 				\
267 	(ifq)->ifq_head = (m); 					\
268 	(ifq)->ifq_len++; 					\
269 } while (0)
270 
271 #define IF_PREPEND(ifq, m) do {		 			\
272 	IF_LOCK(ifq); 						\
273 	_IF_PREPEND(ifq, m); 					\
274 	IF_UNLOCK(ifq); 					\
275 } while (0)
276 
277 #define	_IF_DEQUEUE(ifq, m) do { 				\
278 	(m) = (ifq)->ifq_head; 					\
279 	if (m) { 						\
280 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
281 			(ifq)->ifq_tail = NULL; 		\
282 		(m)->m_nextpkt = NULL; 				\
283 		(ifq)->ifq_len--; 				\
284 	} 							\
285 } while (0)
286 
287 #define IF_DEQUEUE(ifq, m) do { 				\
288 	IF_LOCK(ifq); 						\
289 	_IF_DEQUEUE(ifq, m); 					\
290 	IF_UNLOCK(ifq); 					\
291 } while (0)
292 
293 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
294 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
295 
296 #define _IF_DRAIN(ifq) do { 					\
297 	struct mbuf *m; 					\
298 	for (;;) { 						\
299 		_IF_DEQUEUE(ifq, m); 				\
300 		if (m == NULL) 					\
301 			break; 					\
302 		m_freem(m); 					\
303 	} 							\
304 } while (0)
305 
306 #define IF_DRAIN(ifq) do {					\
307 	IF_LOCK(ifq);						\
308 	_IF_DRAIN(ifq);						\
309 	IF_UNLOCK(ifq);						\
310 } while(0)
311 
312 #ifdef _KERNEL
313 /* interface address change event */
314 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
315 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
316 /* new interface arrival event */
317 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
318 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
319 /* interface departure event */
320 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
321 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
322 
323 #define	IF_AFDATA_LOCK_INIT(ifp)	\
324     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
325 #define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
326 #define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
327 #define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
328 #define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
329 
330 #define	IFF_LOCKGIANT(ifp) do {						\
331 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
332 		mtx_lock(&Giant);					\
333 } while (0)
334 
335 #define	IFF_UNLOCKGIANT(ifp) do {					\
336 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
337 		mtx_unlock(&Giant);					\
338 } while (0)
339 
340 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
341 	    int adjust);
342 #define	IF_HANDOFF(ifq, m, ifp)			\
343 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
344 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
345 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
346 
347 void	if_start(struct ifnet *);
348 
349 #define	IFQ_ENQUEUE(ifq, m, err)					\
350 do {									\
351 	IF_LOCK(ifq);							\
352 	if (ALTQ_IS_ENABLED(ifq))					\
353 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
354 	else {								\
355 		if (_IF_QFULL(ifq)) {					\
356 			m_freem(m);					\
357 			(err) = ENOBUFS;				\
358 		} else {						\
359 			_IF_ENQUEUE(ifq, m);				\
360 			(err) = 0;					\
361 		}							\
362 	}								\
363 	if (err)							\
364 		(ifq)->ifq_drops++;					\
365 	IF_UNLOCK(ifq);							\
366 } while (0)
367 
368 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
369 do {									\
370 	if (TBR_IS_ENABLED(ifq))					\
371 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
372 	else if (ALTQ_IS_ENABLED(ifq))					\
373 		ALTQ_DEQUEUE(ifq, m);					\
374 	else								\
375 		_IF_DEQUEUE(ifq, m);					\
376 } while (0)
377 
378 #define	IFQ_DEQUEUE(ifq, m)						\
379 do {									\
380 	IF_LOCK(ifq);							\
381 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
382 	IF_UNLOCK(ifq);							\
383 } while (0)
384 
385 #define	IFQ_POLL_NOLOCK(ifq, m)						\
386 do {									\
387 	if (TBR_IS_ENABLED(ifq))					\
388 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
389 	else if (ALTQ_IS_ENABLED(ifq))					\
390 		ALTQ_POLL(ifq, m);					\
391 	else								\
392 		_IF_POLL(ifq, m);					\
393 } while (0)
394 
395 #define	IFQ_POLL(ifq, m)						\
396 do {									\
397 	IF_LOCK(ifq);							\
398 	IFQ_POLL_NOLOCK(ifq, m);					\
399 	IF_UNLOCK(ifq);							\
400 } while (0)
401 
402 #define	IFQ_PURGE_NOLOCK(ifq)						\
403 do {									\
404 	if (ALTQ_IS_ENABLED(ifq)) {					\
405 		ALTQ_PURGE(ifq);					\
406 	} else								\
407 		_IF_DRAIN(ifq);						\
408 } while (0)
409 
410 #define	IFQ_PURGE(ifq)							\
411 do {									\
412 	IF_LOCK(ifq);							\
413 	IFQ_PURGE_NOLOCK(ifq);						\
414 	IF_UNLOCK(ifq);							\
415 } while (0)
416 
417 #define	IFQ_SET_READY(ifq)						\
418 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
419 
420 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
421 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
422 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
423 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
424 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
425 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
426 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
427 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
428 
429 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
430 do {									\
431 	int len;							\
432 	short mflags;							\
433 									\
434 	len = (m)->m_pkthdr.len;					\
435 	mflags = (m)->m_flags;						\
436 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
437 	if ((err) == 0) {						\
438 		(ifp)->if_obytes += len + (adj);			\
439 		if (mflags & M_MCAST)					\
440 			(ifp)->if_omcasts++;				\
441 		if (((ifp)->if_flags & IFF_OACTIVE) == 0)		\
442 			if_start(ifp);					\
443 	}								\
444 } while (0)
445 
446 #define	IFQ_HANDOFF(ifp, m, err)					\
447 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
448 
449 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
450 do {									\
451 	(m) = (ifq)->ifq_drv_head;					\
452 	if (m) {							\
453 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
454 			(ifq)->ifq_drv_tail = NULL;			\
455 		(m)->m_nextpkt = NULL;					\
456 		(ifq)->ifq_drv_len--;					\
457 	} else {							\
458 		IFQ_LOCK(ifq);						\
459 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
460 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
461 			struct mbuf *m0;				\
462 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
463 			if (m0 == NULL)					\
464 				break;					\
465 			m0->m_nextpkt = NULL;				\
466 			if ((ifq)->ifq_drv_tail == NULL)		\
467 				(ifq)->ifq_drv_head = m0;		\
468 			else						\
469 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
470 			(ifq)->ifq_drv_tail = m0;			\
471 			(ifq)->ifq_drv_len++;				\
472 		}							\
473 		IFQ_UNLOCK(ifq);					\
474 	}								\
475 } while (0)
476 
477 #define	IFQ_DRV_PREPEND(ifq, m)						\
478 do {									\
479 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
480 	if ((ifq)->ifq_drv_tail == NULL)				\
481 		(ifq)->ifq_drv_tail = (m);				\
482 	(ifq)->ifq_drv_head = (m);					\
483 	(ifq)->ifq_drv_len++;						\
484 } while (0)
485 
486 #define	IFQ_DRV_IS_EMPTY(ifq)						\
487 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
488 
489 #define	IFQ_DRV_PURGE(ifq)						\
490 do {									\
491 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
492 	while((m = n) != NULL) {					\
493 		n = m->m_nextpkt;					\
494 		m_freem(m);						\
495 	}								\
496 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
497 	(ifq)->ifq_drv_len = 0;						\
498 	IFQ_PURGE(ifq);							\
499 } while (0)
500 
501 /*
502  * 72 was chosen below because it is the size of a TCP/IP
503  * header (40) + the minimum mss (32).
504  */
505 #define	IF_MINMTU	72
506 #define	IF_MAXMTU	65535
507 
508 #endif /* _KERNEL */
509 
510 /*
511  * The ifaddr structure contains information about one address
512  * of an interface.  They are maintained by the different address families,
513  * are allocated and attached when an address is set, and are linked
514  * together so all addresses for an interface can be located.
515  *
516  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
517  * chunk of malloc'ed memory, where we store the three addresses
518  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
519  */
520 struct ifaddr {
521 	struct	sockaddr *ifa_addr;	/* address of interface */
522 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
523 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
524 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
525 	struct	if_data if_data;	/* not all members are meaningful */
526 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
527 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
528 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
529 		(int, struct rtentry *, struct rt_addrinfo *);
530 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
531 	u_int	ifa_refcnt;		/* references to this structure */
532 	int	ifa_metric;		/* cost of going out this interface */
533 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
534 		(struct ifaddr *, struct sockaddr *);
535 	struct mtx ifa_mtx;
536 };
537 #define	IFA_ROUTE	RTF_UP		/* route installed */
538 
539 /* for compatibility with other BSDs */
540 #define	ifa_list	ifa_link
541 
542 #define	IFA_LOCK_INIT(ifa)	\
543     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
544 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
545 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
546 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
547 
548 /*
549  * The prefix structure contains information about one prefix
550  * of an interface.  They are maintained by the different address families,
551  * are allocated and attached when a prefix or an address is set,
552  * and are linked together so all prefixes for an interface can be located.
553  */
554 struct ifprefix {
555 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
556 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
557 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
558 	u_char	ifpr_plen;		/* prefix length in bits */
559 	u_char	ifpr_type;		/* protocol dependent prefix type */
560 };
561 
562 /*
563  * Multicast address structure.  This is analogous to the ifaddr
564  * structure except that it keeps track of multicast addresses.
565  * Also, the reference count here is a count of requests for this
566  * address, not a count of pointers to this structure.
567  */
568 struct ifmultiaddr {
569 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
570 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
571 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
572 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
573 	u_int	ifma_refcount;		/* reference count */
574 	void	*ifma_protospec;	/* protocol-specific state, if any */
575 };
576 
577 #ifdef _KERNEL
578 #define	IFAFREE(ifa)					\
579 	do {						\
580 		IFA_LOCK(ifa);				\
581 		KASSERT((ifa)->ifa_refcnt > 0,		\
582 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
583 		if (--(ifa)->ifa_refcnt == 0) {		\
584 			IFA_DESTROY(ifa);		\
585 			free(ifa, M_IFADDR);		\
586 		} else 					\
587 			IFA_UNLOCK(ifa);		\
588 	} while (0)
589 
590 #define IFAREF(ifa)					\
591 	do {						\
592 		IFA_LOCK(ifa);				\
593 		++(ifa)->ifa_refcnt;			\
594 		IFA_UNLOCK(ifa);			\
595 	} while (0)
596 
597 extern	struct mtx ifnet_lock;
598 #define	IFNET_LOCK_INIT() \
599     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
600 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
601 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
602 #define	IFNET_RLOCK()		IFNET_WLOCK()
603 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
604 
605 struct ifindex_entry {
606 	struct	ifnet *ife_ifnet;
607 	struct	ifaddr *ife_ifnet_addr;
608 	struct cdev *ife_dev;
609 };
610 
611 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
612 /*
613  * Given the index, ifaddr_byindex() returns the one and only
614  * link-level ifaddr for the interface. You are not supposed to use
615  * it to traverse the list of addresses associated to the interface.
616  */
617 #define ifaddr_byindex(idx)	ifindex_table[(idx)].ife_ifnet_addr
618 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
619 
620 extern	struct ifnethead ifnet;
621 extern	struct ifindex_entry *ifindex_table;
622 extern	int ifqmaxlen;
623 extern	struct ifnet *loif;	/* first loopback interface */
624 extern	int if_index;
625 
626 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
627 int	if_allmulti(struct ifnet *, int);
628 void	if_attach(struct ifnet *);
629 int	if_delmulti(struct ifnet *, struct sockaddr *);
630 void	if_detach(struct ifnet *);
631 void	if_down(struct ifnet *);
632 void	if_initname(struct ifnet *, const char *, int);
633 void	if_link_state_change(struct ifnet *, int);
634 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
635 int	if_setlladdr(struct ifnet *, const u_char *, int);
636 void	if_up(struct ifnet *);
637 /*void	ifinit(void);*/ /* declared in systm.h for main() */
638 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
639 int	ifpromisc(struct ifnet *, int);
640 struct	ifnet *ifunit(const char *);
641 
642 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
643 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
644 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
645 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
646 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
647 
648 struct	ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
649 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
650 
651 #define IF_LLADDR(ifp)							\
652     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
653 
654 #ifdef DEVICE_POLLING
655 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
656 
657 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
658 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
659 int    ether_poll_deregister(struct ifnet *ifp);
660 #endif /* DEVICE_POLLING */
661 
662 #endif /* _KERNEL */
663 
664 #endif /* !_NET_IF_VAR_H_ */
665