xref: /freebsd/sys/net/if_var.h (revision 78007886c995898a9494648343e5236bca1cbba3)
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 struct  ifvlantrunk;
73 #endif
74 
75 #include <sys/queue.h>		/* get TAILQ macros */
76 
77 #ifdef _KERNEL
78 #include <sys/mbuf.h>
79 #include <sys/eventhandler.h>
80 #endif /* _KERNEL */
81 #include <sys/lock.h>		/* XXX */
82 #include <sys/mutex.h>		/* XXX */
83 #include <sys/event.h>		/* XXX */
84 #include <sys/_task.h>
85 
86 #define	IF_DUNIT_NONE	-1
87 
88 #include <altq/if_altq.h>
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 TAILQ_HEAD(ifgrouphead, ifg_group);
95 
96 /*
97  * Structure defining a queue for a network interface.
98  */
99 struct	ifqueue {
100 	struct	mbuf *ifq_head;
101 	struct	mbuf *ifq_tail;
102 	int	ifq_len;
103 	int	ifq_maxlen;
104 	int	ifq_drops;
105 	struct	mtx ifq_mtx;
106 };
107 
108 /*
109  * Structure defining a network interface.
110  *
111  * (Would like to call this struct ``if'', but C isn't PL/1.)
112  */
113 
114 struct ifnet {
115 	void	*if_softc;		/* pointer to driver state */
116 	void	*if_l2com;		/* pointer to protocol bits */
117 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
118 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
119 	const char *if_dname;		/* driver name */
120 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
121 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
122 		/*
123 		 * if_addrhead is the list of all addresses associated to
124 		 * an interface.
125 		 * Some code in the kernel assumes that first element
126 		 * of the list has type AF_LINK, and contains sockaddr_dl
127 		 * addresses which store the link-level address and the name
128 		 * of the interface.
129 		 * However, access to the AF_LINK address through this
130 		 * field is deprecated. Use if_addr or ifaddr_byindex() instead.
131 		 */
132 	struct	knlist if_klist;	/* events attached to this if */
133 	int	if_pcount;		/* number of promiscuous listeners */
134 	struct	carp_if *if_carp;	/* carp interface structure */
135 	struct	bpf_if *if_bpf;		/* packet filter structure */
136 	u_short	if_index;		/* numeric abbreviation for this if  */
137 	short	if_timer;		/* time 'til if_watchdog called */
138 	struct  ifvlantrunk *if_vlantrunk; /* pointer to 802.1q data */
139 	int	if_flags;		/* up/down, broadcast, etc. */
140 	int	if_capabilities;	/* interface features & capabilities */
141 	int	if_capenable;		/* enabled features & capabilities */
142 	void	*if_linkmib;		/* link-type-specific MIB data */
143 	size_t	if_linkmiblen;		/* length of above data */
144 	struct	if_data if_data;
145 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
146 	int	if_amcount;		/* number of all-multicast requests */
147 /* procedure handles */
148 	int	(*if_output)		/* output routine (enqueue) */
149 		(struct ifnet *, struct mbuf *, struct sockaddr *,
150 		     struct rtentry *);
151 	void	(*if_input)		/* input routine (from h/w driver) */
152 		(struct ifnet *, struct mbuf *);
153 	void	(*if_start)		/* initiate output routine */
154 		(struct ifnet *);
155 	int	(*if_ioctl)		/* ioctl routine */
156 		(struct ifnet *, u_long, caddr_t);
157 	void	(*if_watchdog)		/* timer routine */
158 		(struct ifnet *);
159 	void	(*if_init)		/* Init routine */
160 		(void *);
161 	int	(*if_resolvemulti)	/* validate/resolve multicast */
162 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
163 	struct	ifaddr	*if_addr;	/* pointer to link-level address */
164 	void	*if_spare2;		/* spare pointer 2 */
165 	void	*if_spare3;		/* spare pointer 3 */
166 	int	if_drv_flags;		/* driver-managed status flags */
167 	u_int	if_spare_flags2;	/* spare flags 2 */
168 	struct  ifaltq if_snd;		/* output queue (includes altq) */
169 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
170 
171 	void	*if_bridge;		/* bridge glue */
172 
173 	struct	lltable *lltables;	/* list of L3-L2 resolution tables */
174 
175 	struct	label *if_label;	/* interface MAC label */
176 
177 	/* these are only used by IPv6 */
178 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
179 	void	*if_afdata[AF_MAX];
180 	int	if_afdata_initialized;
181 	struct	mtx if_afdata_mtx;
182 	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
183 	struct	task if_linktask;	/* task for link change events */
184 	struct	mtx if_addr_mtx;	/* mutex to protect address lists */
185 	LIST_ENTRY(ifnet) if_clones;	/* interfaces of a cloner */
186 	TAILQ_HEAD(, ifg_list) if_groups; /* linked list of groups per if */
187 					/* protected by if_addr_mtx */
188 	void	*if_pf_kif;
189 	void	*if_lagg;		/* lagg glue */
190 };
191 
192 typedef void if_init_f_t(void *);
193 
194 /*
195  * XXX These aliases are terribly dangerous because they could apply
196  * to anything.
197  */
198 #define	if_mtu		if_data.ifi_mtu
199 #define	if_type		if_data.ifi_type
200 #define if_physical	if_data.ifi_physical
201 #define	if_addrlen	if_data.ifi_addrlen
202 #define	if_hdrlen	if_data.ifi_hdrlen
203 #define	if_metric	if_data.ifi_metric
204 #define	if_link_state	if_data.ifi_link_state
205 #define	if_baudrate	if_data.ifi_baudrate
206 #define	if_hwassist	if_data.ifi_hwassist
207 #define	if_ipackets	if_data.ifi_ipackets
208 #define	if_ierrors	if_data.ifi_ierrors
209 #define	if_opackets	if_data.ifi_opackets
210 #define	if_oerrors	if_data.ifi_oerrors
211 #define	if_collisions	if_data.ifi_collisions
212 #define	if_ibytes	if_data.ifi_ibytes
213 #define	if_obytes	if_data.ifi_obytes
214 #define	if_imcasts	if_data.ifi_imcasts
215 #define	if_omcasts	if_data.ifi_omcasts
216 #define	if_iqdrops	if_data.ifi_iqdrops
217 #define	if_noproto	if_data.ifi_noproto
218 #define	if_lastchange	if_data.ifi_lastchange
219 #define if_recvquota	if_data.ifi_recvquota
220 #define	if_xmitquota	if_data.ifi_xmitquota
221 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
222 
223 /* for compatibility with other BSDs */
224 #define	if_addrlist	if_addrhead
225 #define	if_list		if_link
226 #define	if_name(ifp)	((ifp)->if_xname)
227 
228 /*
229  * Locks for address lists on the network interface.
230  */
231 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
232 				    "if_addr_mtx", NULL, MTX_DEF)
233 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
234 #define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
235 #define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
236 #define	IF_ADDR_LOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
237 
238 /*
239  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
240  * are queues of messages stored on ifqueue structures
241  * (defined above).  Entries are added to and deleted from these structures
242  * by these macros, which should be called with ipl raised to splimp().
243  */
244 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
245 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
246 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
247 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
248 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
249 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
250 
251 #define	_IF_ENQUEUE(ifq, m) do { 				\
252 	(m)->m_nextpkt = NULL;					\
253 	if ((ifq)->ifq_tail == NULL) 				\
254 		(ifq)->ifq_head = m; 				\
255 	else 							\
256 		(ifq)->ifq_tail->m_nextpkt = m; 		\
257 	(ifq)->ifq_tail = m; 					\
258 	(ifq)->ifq_len++; 					\
259 } while (0)
260 
261 #define IF_ENQUEUE(ifq, m) do {					\
262 	IF_LOCK(ifq); 						\
263 	_IF_ENQUEUE(ifq, m); 					\
264 	IF_UNLOCK(ifq); 					\
265 } while (0)
266 
267 #define	_IF_PREPEND(ifq, m) do {				\
268 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
269 	if ((ifq)->ifq_tail == NULL) 				\
270 		(ifq)->ifq_tail = (m); 				\
271 	(ifq)->ifq_head = (m); 					\
272 	(ifq)->ifq_len++; 					\
273 } while (0)
274 
275 #define IF_PREPEND(ifq, m) do {		 			\
276 	IF_LOCK(ifq); 						\
277 	_IF_PREPEND(ifq, m); 					\
278 	IF_UNLOCK(ifq); 					\
279 } while (0)
280 
281 #define	_IF_DEQUEUE(ifq, m) do { 				\
282 	(m) = (ifq)->ifq_head; 					\
283 	if (m) { 						\
284 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
285 			(ifq)->ifq_tail = NULL; 		\
286 		(m)->m_nextpkt = NULL; 				\
287 		(ifq)->ifq_len--; 				\
288 	} 							\
289 } while (0)
290 
291 #define IF_DEQUEUE(ifq, m) do { 				\
292 	IF_LOCK(ifq); 						\
293 	_IF_DEQUEUE(ifq, m); 					\
294 	IF_UNLOCK(ifq); 					\
295 } while (0)
296 
297 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
298 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
299 
300 #define _IF_DRAIN(ifq) do { 					\
301 	struct mbuf *m; 					\
302 	for (;;) { 						\
303 		_IF_DEQUEUE(ifq, m); 				\
304 		if (m == NULL) 					\
305 			break; 					\
306 		m_freem(m); 					\
307 	} 							\
308 } while (0)
309 
310 #define IF_DRAIN(ifq) do {					\
311 	IF_LOCK(ifq);						\
312 	_IF_DRAIN(ifq);						\
313 	IF_UNLOCK(ifq);						\
314 } while(0)
315 
316 #ifdef _KERNEL
317 /* interface address change event */
318 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
319 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
320 /* new interface arrival event */
321 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
322 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
323 /* interface departure event */
324 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
325 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
326 
327 /*
328  * interface groups
329  */
330 struct ifg_group {
331 	char				 ifg_group[IFNAMSIZ];
332 	u_int				 ifg_refcnt;
333 	void				*ifg_pf_kif;
334 	TAILQ_HEAD(, ifg_member)	 ifg_members;
335 	TAILQ_ENTRY(ifg_group)		 ifg_next;
336 };
337 
338 struct ifg_member {
339 	TAILQ_ENTRY(ifg_member)	 ifgm_next;
340 	struct ifnet		*ifgm_ifp;
341 };
342 
343 struct ifg_list {
344 	struct ifg_group	*ifgl_group;
345 	TAILQ_ENTRY(ifg_list)	 ifgl_next;
346 };
347 
348 /* group attach event */
349 typedef void (*group_attach_event_handler_t)(void *, struct ifg_group *);
350 EVENTHANDLER_DECLARE(group_attach_event, group_attach_event_handler_t);
351 /* group detach event */
352 typedef void (*group_detach_event_handler_t)(void *, struct ifg_group *);
353 EVENTHANDLER_DECLARE(group_detach_event, group_detach_event_handler_t);
354 /* group change event */
355 typedef void (*group_change_event_handler_t)(void *, const char *);
356 EVENTHANDLER_DECLARE(group_change_event, group_change_event_handler_t);
357 
358 #define	IF_AFDATA_LOCK_INIT(ifp)	\
359     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
360 #define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
361 #define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
362 #define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
363 #define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
364 
365 #define	IFF_LOCKGIANT(ifp) do {						\
366 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
367 		mtx_lock(&Giant);					\
368 } while (0)
369 
370 #define	IFF_UNLOCKGIANT(ifp) do {					\
371 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
372 		mtx_unlock(&Giant);					\
373 } while (0)
374 
375 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
376 	    int adjust);
377 #define	IF_HANDOFF(ifq, m, ifp)			\
378 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
379 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
380 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
381 
382 void	if_start(struct ifnet *);
383 
384 #define	IFQ_ENQUEUE(ifq, m, err)					\
385 do {									\
386 	IF_LOCK(ifq);							\
387 	if (ALTQ_IS_ENABLED(ifq))					\
388 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
389 	else {								\
390 		if (_IF_QFULL(ifq)) {					\
391 			m_freem(m);					\
392 			(err) = ENOBUFS;				\
393 		} else {						\
394 			_IF_ENQUEUE(ifq, m);				\
395 			(err) = 0;					\
396 		}							\
397 	}								\
398 	if (err)							\
399 		(ifq)->ifq_drops++;					\
400 	IF_UNLOCK(ifq);							\
401 } while (0)
402 
403 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
404 do {									\
405 	if (TBR_IS_ENABLED(ifq))					\
406 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
407 	else if (ALTQ_IS_ENABLED(ifq))					\
408 		ALTQ_DEQUEUE(ifq, m);					\
409 	else								\
410 		_IF_DEQUEUE(ifq, m);					\
411 } while (0)
412 
413 #define	IFQ_DEQUEUE(ifq, m)						\
414 do {									\
415 	IF_LOCK(ifq);							\
416 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
417 	IF_UNLOCK(ifq);							\
418 } while (0)
419 
420 #define	IFQ_POLL_NOLOCK(ifq, m)						\
421 do {									\
422 	if (TBR_IS_ENABLED(ifq))					\
423 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
424 	else if (ALTQ_IS_ENABLED(ifq))					\
425 		ALTQ_POLL(ifq, m);					\
426 	else								\
427 		_IF_POLL(ifq, m);					\
428 } while (0)
429 
430 #define	IFQ_POLL(ifq, m)						\
431 do {									\
432 	IF_LOCK(ifq);							\
433 	IFQ_POLL_NOLOCK(ifq, m);					\
434 	IF_UNLOCK(ifq);							\
435 } while (0)
436 
437 #define	IFQ_PURGE_NOLOCK(ifq)						\
438 do {									\
439 	if (ALTQ_IS_ENABLED(ifq)) {					\
440 		ALTQ_PURGE(ifq);					\
441 	} else								\
442 		_IF_DRAIN(ifq);						\
443 } while (0)
444 
445 #define	IFQ_PURGE(ifq)							\
446 do {									\
447 	IF_LOCK(ifq);							\
448 	IFQ_PURGE_NOLOCK(ifq);						\
449 	IF_UNLOCK(ifq);							\
450 } while (0)
451 
452 #define	IFQ_SET_READY(ifq)						\
453 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
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 /*
465  * The IFF_DRV_OACTIVE test should really occur in the device driver, not in
466  * the handoff logic, as that flag is locked by the device driver.
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_drv_flags & IFF_DRV_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  */
605 struct ifmultiaddr {
606 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
607 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
608 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
609 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
610 	u_int	ifma_refcount;		/* reference count */
611 	void	*ifma_protospec;	/* protocol-specific state, if any */
612 	struct	ifmultiaddr *ifma_llifma; /* pointer to ifma for ifma_lladdr */
613 };
614 
615 #ifdef _KERNEL
616 #define	IFAFREE(ifa)					\
617 	do {						\
618 		IFA_LOCK(ifa);				\
619 		KASSERT((ifa)->ifa_refcnt > 0,		\
620 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
621 		if (--(ifa)->ifa_refcnt == 0) {		\
622 			IFA_DESTROY(ifa);		\
623 			free(ifa, M_IFADDR);		\
624 		} else 					\
625 			IFA_UNLOCK(ifa);		\
626 	} while (0)
627 
628 #define IFAREF(ifa)					\
629 	do {						\
630 		IFA_LOCK(ifa);				\
631 		++(ifa)->ifa_refcnt;			\
632 		IFA_UNLOCK(ifa);			\
633 	} while (0)
634 
635 extern	struct mtx ifnet_lock;
636 #define	IFNET_LOCK_INIT() \
637     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
638 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
639 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
640 #define	IFNET_RLOCK()		IFNET_WLOCK()
641 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
642 
643 struct ifindex_entry {
644 	struct	ifnet *ife_ifnet;
645 	struct cdev *ife_dev;
646 };
647 
648 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
649 /*
650  * Given the index, ifaddr_byindex() returns the one and only
651  * link-level ifaddr for the interface. You are not supposed to use
652  * it to traverse the list of addresses associated to the interface.
653  */
654 #define ifaddr_byindex(idx)	ifnet_byindex(idx)->if_addr
655 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
656 
657 extern	struct ifnethead ifnet;
658 extern	struct ifindex_entry *ifindex_table;
659 extern	int ifqmaxlen;
660 extern	struct ifnet *loif;	/* first loopback interface */
661 extern	int if_index;
662 
663 int	if_addgroup(struct ifnet *, const char *);
664 int	if_delgroup(struct ifnet *, const char *);
665 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
666 int	if_allmulti(struct ifnet *, int);
667 struct	ifnet* if_alloc(u_char);
668 void	if_attach(struct ifnet *);
669 int	if_delmulti(struct ifnet *, struct sockaddr *);
670 void	if_delmulti_ifma(struct ifmultiaddr *);
671 void	if_detach(struct ifnet *);
672 void	if_purgeaddrs(struct ifnet *);
673 void	if_down(struct ifnet *);
674 struct ifmultiaddr *
675 	if_findmulti(struct ifnet *, struct sockaddr *);
676 void	if_free(struct ifnet *);
677 void	if_free_type(struct ifnet *, u_char);
678 void	if_initname(struct ifnet *, const char *, int);
679 void	if_link_state_change(struct ifnet *, int);
680 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
681 int	if_setlladdr(struct ifnet *, const u_char *, int);
682 void	if_up(struct ifnet *);
683 /*void	ifinit(void);*/ /* declared in systm.h for main() */
684 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
685 int	ifpromisc(struct ifnet *, int);
686 struct	ifnet *ifunit(const char *);
687 
688 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
689 struct	ifaddr *ifa_ifwithbroadaddr(struct sockaddr *);
690 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
691 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
692 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
693 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
694 
695 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
696 
697 typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
698 typedef	void if_com_free_t(void *com, u_char type);
699 void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
700 void	if_deregister_com_alloc(u_char type);
701 
702 #define IF_LLADDR(ifp)							\
703     LLADDR((struct sockaddr_dl *)((ifp)->if_addr->ifa_addr))
704 
705 #ifdef DEVICE_POLLING
706 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS };
707 
708 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
709 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
710 int    ether_poll_deregister(struct ifnet *ifp);
711 #endif /* DEVICE_POLLING */
712 
713 #endif /* _KERNEL */
714 
715 #endif /* !_NET_IF_VAR_H_ */
716