xref: /freebsd/sys/net/if_var.h (revision 8847579c57d6aff2b3371c707dce7a2cee8389aa)
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 capabilities */
141 	int	if_capenable;		/* enabled features */
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 };
190 
191 typedef void if_init_f_t(void *);
192 
193 /*
194  * XXX These aliases are terribly dangerous because they could apply
195  * to anything.
196  */
197 #define	if_mtu		if_data.ifi_mtu
198 #define	if_type		if_data.ifi_type
199 #define if_physical	if_data.ifi_physical
200 #define	if_addrlen	if_data.ifi_addrlen
201 #define	if_hdrlen	if_data.ifi_hdrlen
202 #define	if_metric	if_data.ifi_metric
203 #define	if_link_state	if_data.ifi_link_state
204 #define	if_baudrate	if_data.ifi_baudrate
205 #define	if_hwassist	if_data.ifi_hwassist
206 #define	if_ipackets	if_data.ifi_ipackets
207 #define	if_ierrors	if_data.ifi_ierrors
208 #define	if_opackets	if_data.ifi_opackets
209 #define	if_oerrors	if_data.ifi_oerrors
210 #define	if_collisions	if_data.ifi_collisions
211 #define	if_ibytes	if_data.ifi_ibytes
212 #define	if_obytes	if_data.ifi_obytes
213 #define	if_imcasts	if_data.ifi_imcasts
214 #define	if_omcasts	if_data.ifi_omcasts
215 #define	if_iqdrops	if_data.ifi_iqdrops
216 #define	if_noproto	if_data.ifi_noproto
217 #define	if_lastchange	if_data.ifi_lastchange
218 #define if_recvquota	if_data.ifi_recvquota
219 #define	if_xmitquota	if_data.ifi_xmitquota
220 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
221 
222 /* for compatibility with other BSDs */
223 #define	if_addrlist	if_addrhead
224 #define	if_list		if_link
225 
226 /*
227  * Locks for address lists on the network interface.
228  */
229 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
230 				    "if_addr_mtx", NULL, MTX_DEF)
231 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
232 #define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
233 #define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
234 #define	IF_ADDR_LOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
235 
236 /*
237  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
238  * are queues of messages stored on ifqueue structures
239  * (defined above).  Entries are added to and deleted from these structures
240  * by these macros, which should be called with ipl raised to splimp().
241  */
242 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
243 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
244 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
245 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
246 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
247 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
248 
249 #define	_IF_ENQUEUE(ifq, m) do { 				\
250 	(m)->m_nextpkt = NULL;					\
251 	if ((ifq)->ifq_tail == NULL) 				\
252 		(ifq)->ifq_head = m; 				\
253 	else 							\
254 		(ifq)->ifq_tail->m_nextpkt = m; 		\
255 	(ifq)->ifq_tail = m; 					\
256 	(ifq)->ifq_len++; 					\
257 } while (0)
258 
259 #define IF_ENQUEUE(ifq, m) do {					\
260 	IF_LOCK(ifq); 						\
261 	_IF_ENQUEUE(ifq, m); 					\
262 	IF_UNLOCK(ifq); 					\
263 } while (0)
264 
265 #define	_IF_PREPEND(ifq, m) do {				\
266 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
267 	if ((ifq)->ifq_tail == NULL) 				\
268 		(ifq)->ifq_tail = (m); 				\
269 	(ifq)->ifq_head = (m); 					\
270 	(ifq)->ifq_len++; 					\
271 } while (0)
272 
273 #define IF_PREPEND(ifq, m) do {		 			\
274 	IF_LOCK(ifq); 						\
275 	_IF_PREPEND(ifq, m); 					\
276 	IF_UNLOCK(ifq); 					\
277 } while (0)
278 
279 #define	_IF_DEQUEUE(ifq, m) do { 				\
280 	(m) = (ifq)->ifq_head; 					\
281 	if (m) { 						\
282 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
283 			(ifq)->ifq_tail = NULL; 		\
284 		(m)->m_nextpkt = NULL; 				\
285 		(ifq)->ifq_len--; 				\
286 	} 							\
287 } while (0)
288 
289 #define IF_DEQUEUE(ifq, m) do { 				\
290 	IF_LOCK(ifq); 						\
291 	_IF_DEQUEUE(ifq, m); 					\
292 	IF_UNLOCK(ifq); 					\
293 } while (0)
294 
295 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
296 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
297 
298 #define _IF_DRAIN(ifq) do { 					\
299 	struct mbuf *m; 					\
300 	for (;;) { 						\
301 		_IF_DEQUEUE(ifq, m); 				\
302 		if (m == NULL) 					\
303 			break; 					\
304 		m_freem(m); 					\
305 	} 							\
306 } while (0)
307 
308 #define IF_DRAIN(ifq) do {					\
309 	IF_LOCK(ifq);						\
310 	_IF_DRAIN(ifq);						\
311 	IF_UNLOCK(ifq);						\
312 } while(0)
313 
314 #ifdef _KERNEL
315 /* interface address change event */
316 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
317 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
318 /* new interface arrival event */
319 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
320 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
321 /* interface departure event */
322 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
323 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
324 
325 /*
326  * interface groups
327  */
328 struct ifg_group {
329 	char				 ifg_group[IFNAMSIZ];
330 	u_int				 ifg_refcnt;
331 	void				*ifg_pf_kif;
332 	TAILQ_HEAD(, ifg_member)	 ifg_members;
333 	TAILQ_ENTRY(ifg_group)		 ifg_next;
334 };
335 
336 struct ifg_member {
337 	TAILQ_ENTRY(ifg_member)	 ifgm_next;
338 	struct ifnet		*ifgm_ifp;
339 };
340 
341 struct ifg_list {
342 	struct ifg_group	*ifgl_group;
343 	TAILQ_ENTRY(ifg_list)	 ifgl_next;
344 };
345 
346 /* group attach event */
347 typedef void (*group_attach_event_handler_t)(void *, struct ifg_group *);
348 EVENTHANDLER_DECLARE(group_attach_event, group_attach_event_handler_t);
349 /* group detach event */
350 typedef void (*group_detach_event_handler_t)(void *, struct ifg_group *);
351 EVENTHANDLER_DECLARE(group_detach_event, group_detach_event_handler_t);
352 /* group change event */
353 typedef void (*group_change_event_handler_t)(void *, const char *);
354 EVENTHANDLER_DECLARE(group_change_event, group_change_event_handler_t);
355 
356 #define	IF_AFDATA_LOCK_INIT(ifp)	\
357     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
358 #define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
359 #define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
360 #define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
361 #define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
362 
363 #define	IFF_LOCKGIANT(ifp) do {						\
364 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
365 		mtx_lock(&Giant);					\
366 } while (0)
367 
368 #define	IFF_UNLOCKGIANT(ifp) do {					\
369 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
370 		mtx_unlock(&Giant);					\
371 } while (0)
372 
373 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
374 	    int adjust);
375 #define	IF_HANDOFF(ifq, m, ifp)			\
376 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
377 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
378 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
379 
380 void	if_start(struct ifnet *);
381 
382 #define	IFQ_ENQUEUE(ifq, m, err)					\
383 do {									\
384 	IF_LOCK(ifq);							\
385 	if (ALTQ_IS_ENABLED(ifq))					\
386 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
387 	else {								\
388 		if (_IF_QFULL(ifq)) {					\
389 			m_freem(m);					\
390 			(err) = ENOBUFS;				\
391 		} else {						\
392 			_IF_ENQUEUE(ifq, m);				\
393 			(err) = 0;					\
394 		}							\
395 	}								\
396 	if (err)							\
397 		(ifq)->ifq_drops++;					\
398 	IF_UNLOCK(ifq);							\
399 } while (0)
400 
401 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
402 do {									\
403 	if (TBR_IS_ENABLED(ifq))					\
404 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
405 	else if (ALTQ_IS_ENABLED(ifq))					\
406 		ALTQ_DEQUEUE(ifq, m);					\
407 	else								\
408 		_IF_DEQUEUE(ifq, m);					\
409 } while (0)
410 
411 #define	IFQ_DEQUEUE(ifq, m)						\
412 do {									\
413 	IF_LOCK(ifq);							\
414 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
415 	IF_UNLOCK(ifq);							\
416 } while (0)
417 
418 #define	IFQ_POLL_NOLOCK(ifq, m)						\
419 do {									\
420 	if (TBR_IS_ENABLED(ifq))					\
421 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
422 	else if (ALTQ_IS_ENABLED(ifq))					\
423 		ALTQ_POLL(ifq, m);					\
424 	else								\
425 		_IF_POLL(ifq, m);					\
426 } while (0)
427 
428 #define	IFQ_POLL(ifq, m)						\
429 do {									\
430 	IF_LOCK(ifq);							\
431 	IFQ_POLL_NOLOCK(ifq, m);					\
432 	IF_UNLOCK(ifq);							\
433 } while (0)
434 
435 #define	IFQ_PURGE_NOLOCK(ifq)						\
436 do {									\
437 	if (ALTQ_IS_ENABLED(ifq)) {					\
438 		ALTQ_PURGE(ifq);					\
439 	} else								\
440 		_IF_DRAIN(ifq);						\
441 } while (0)
442 
443 #define	IFQ_PURGE(ifq)							\
444 do {									\
445 	IF_LOCK(ifq);							\
446 	IFQ_PURGE_NOLOCK(ifq);						\
447 	IF_UNLOCK(ifq);							\
448 } while (0)
449 
450 #define	IFQ_SET_READY(ifq)						\
451 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
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 /*
463  * The IFF_DRV_OACTIVE test should really occur in the device driver, not in
464  * the handoff logic, as that flag is locked by the device driver.
465  */
466 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
467 do {									\
468 	int len;							\
469 	short mflags;							\
470 									\
471 	len = (m)->m_pkthdr.len;					\
472 	mflags = (m)->m_flags;						\
473 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
474 	if ((err) == 0) {						\
475 		(ifp)->if_obytes += len + (adj);			\
476 		if (mflags & M_MCAST)					\
477 			(ifp)->if_omcasts++;				\
478 		if (((ifp)->if_drv_flags & IFF_DRV_OACTIVE) == 0)	\
479 			if_start(ifp);					\
480 	}								\
481 } while (0)
482 
483 #define	IFQ_HANDOFF(ifp, m, err)					\
484 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
485 
486 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
487 do {									\
488 	(m) = (ifq)->ifq_drv_head;					\
489 	if (m) {							\
490 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
491 			(ifq)->ifq_drv_tail = NULL;			\
492 		(m)->m_nextpkt = NULL;					\
493 		(ifq)->ifq_drv_len--;					\
494 	} else {							\
495 		IFQ_LOCK(ifq);						\
496 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
497 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
498 			struct mbuf *m0;				\
499 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
500 			if (m0 == NULL)					\
501 				break;					\
502 			m0->m_nextpkt = NULL;				\
503 			if ((ifq)->ifq_drv_tail == NULL)		\
504 				(ifq)->ifq_drv_head = m0;		\
505 			else						\
506 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
507 			(ifq)->ifq_drv_tail = m0;			\
508 			(ifq)->ifq_drv_len++;				\
509 		}							\
510 		IFQ_UNLOCK(ifq);					\
511 	}								\
512 } while (0)
513 
514 #define	IFQ_DRV_PREPEND(ifq, m)						\
515 do {									\
516 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
517 	if ((ifq)->ifq_drv_tail == NULL)				\
518 		(ifq)->ifq_drv_tail = (m);				\
519 	(ifq)->ifq_drv_head = (m);					\
520 	(ifq)->ifq_drv_len++;						\
521 } while (0)
522 
523 #define	IFQ_DRV_IS_EMPTY(ifq)						\
524 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
525 
526 #define	IFQ_DRV_PURGE(ifq)						\
527 do {									\
528 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
529 	while((m = n) != NULL) {					\
530 		n = m->m_nextpkt;					\
531 		m_freem(m);						\
532 	}								\
533 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
534 	(ifq)->ifq_drv_len = 0;						\
535 	IFQ_PURGE(ifq);							\
536 } while (0)
537 
538 /*
539  * 72 was chosen below because it is the size of a TCP/IP
540  * header (40) + the minimum mss (32).
541  */
542 #define	IF_MINMTU	72
543 #define	IF_MAXMTU	65535
544 
545 #endif /* _KERNEL */
546 
547 /*
548  * The ifaddr structure contains information about one address
549  * of an interface.  They are maintained by the different address families,
550  * are allocated and attached when an address is set, and are linked
551  * together so all addresses for an interface can be located.
552  *
553  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
554  * chunk of malloc'ed memory, where we store the three addresses
555  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
556  */
557 struct ifaddr {
558 	struct	sockaddr *ifa_addr;	/* address of interface */
559 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
560 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
561 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
562 	struct	if_data if_data;	/* not all members are meaningful */
563 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
564 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
565 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
566 		(int, struct rtentry *, struct rt_addrinfo *);
567 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
568 	u_int	ifa_refcnt;		/* references to this structure */
569 	int	ifa_metric;		/* cost of going out this interface */
570 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
571 		(struct ifaddr *, struct sockaddr *);
572 	struct mtx ifa_mtx;
573 };
574 #define	IFA_ROUTE	RTF_UP		/* route installed */
575 
576 /* for compatibility with other BSDs */
577 #define	ifa_list	ifa_link
578 
579 #define	IFA_LOCK_INIT(ifa)	\
580     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
581 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
582 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
583 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
584 
585 /*
586  * The prefix structure contains information about one prefix
587  * of an interface.  They are maintained by the different address families,
588  * are allocated and attached when a prefix or an address is set,
589  * and are linked together so all prefixes for an interface can be located.
590  */
591 struct ifprefix {
592 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
593 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
594 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
595 	u_char	ifpr_plen;		/* prefix length in bits */
596 	u_char	ifpr_type;		/* protocol dependent prefix type */
597 };
598 
599 /*
600  * Multicast address structure.  This is analogous to the ifaddr
601  * structure except that it keeps track of multicast addresses.
602  * Also, the reference count here is a count of requests for this
603  * address, not a count of pointers to this structure.
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 };
613 
614 #ifdef _KERNEL
615 #define	IFAFREE(ifa)					\
616 	do {						\
617 		IFA_LOCK(ifa);				\
618 		KASSERT((ifa)->ifa_refcnt > 0,		\
619 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
620 		if (--(ifa)->ifa_refcnt == 0) {		\
621 			IFA_DESTROY(ifa);		\
622 			free(ifa, M_IFADDR);		\
623 		} else 					\
624 			IFA_UNLOCK(ifa);		\
625 	} while (0)
626 
627 #define IFAREF(ifa)					\
628 	do {						\
629 		IFA_LOCK(ifa);				\
630 		++(ifa)->ifa_refcnt;			\
631 		IFA_UNLOCK(ifa);			\
632 	} while (0)
633 
634 extern	struct mtx ifnet_lock;
635 #define	IFNET_LOCK_INIT() \
636     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
637 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
638 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
639 #define	IFNET_RLOCK()		IFNET_WLOCK()
640 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
641 
642 struct ifindex_entry {
643 	struct	ifnet *ife_ifnet;
644 	struct cdev *ife_dev;
645 };
646 
647 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
648 /*
649  * Given the index, ifaddr_byindex() returns the one and only
650  * link-level ifaddr for the interface. You are not supposed to use
651  * it to traverse the list of addresses associated to the interface.
652  */
653 #define ifaddr_byindex(idx)	ifnet_byindex(idx)->if_addr
654 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
655 
656 extern	struct ifnethead ifnet;
657 extern	struct ifindex_entry *ifindex_table;
658 extern	int ifqmaxlen;
659 extern	struct ifnet *loif;	/* first loopback interface */
660 extern	int if_index;
661 
662 int	if_addgroup(struct ifnet *, const char *);
663 int	if_delgroup(struct ifnet *, const char *);
664 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
665 int	if_allmulti(struct ifnet *, int);
666 struct	ifnet* if_alloc(u_char);
667 void	if_attach(struct ifnet *);
668 int	if_delmulti(struct ifnet *, struct sockaddr *);
669 void	if_detach(struct ifnet *);
670 void	if_purgeaddrs(struct ifnet *);
671 void	if_down(struct ifnet *);
672 void	if_free(struct ifnet *);
673 void	if_free_type(struct ifnet *, u_char);
674 void	if_initname(struct ifnet *, const char *, int);
675 void	if_link_state_change(struct ifnet *, int);
676 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
677 int	if_setlladdr(struct ifnet *, const u_char *, int);
678 void	if_up(struct ifnet *);
679 /*void	ifinit(void);*/ /* declared in systm.h for main() */
680 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
681 int	ifpromisc(struct ifnet *, int);
682 struct	ifnet *ifunit(const char *);
683 
684 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
685 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
686 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
687 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
688 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
689 
690 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
691 
692 typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
693 typedef	void if_com_free_t(void *com, u_char type);
694 void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
695 void	if_deregister_com_alloc(u_char type);
696 
697 #define IF_LLADDR(ifp)							\
698     LLADDR((struct sockaddr_dl *)((ifp)->if_addr->ifa_addr))
699 
700 #ifdef DEVICE_POLLING
701 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS };
702 
703 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
704 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
705 int    ether_poll_deregister(struct ifnet *ifp);
706 #endif /* DEVICE_POLLING */
707 
708 #endif /* _KERNEL */
709 
710 #endif /* !_NET_IF_VAR_H_ */
711