xref: /freebsd/sys/net/if_var.h (revision b3aaa0cc21c63d388230c7ef2a80abd631ff20d5)
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 #include <sys/buf_ring.h>
81 #endif /* _KERNEL */
82 #include <sys/lock.h>		/* XXX */
83 #include <sys/mutex.h>		/* XXX */
84 #include <sys/rwlock.h>		/* XXX */
85 #include <sys/event.h>		/* XXX */
86 #include <sys/_task.h>
87 
88 #define	IF_DUNIT_NONE	-1
89 
90 #include <altq/if_altq.h>
91 
92 TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
93 TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
94 TAILQ_HEAD(ifprefixhead, ifprefix);
95 TAILQ_HEAD(ifmultihead, ifmultiaddr);
96 TAILQ_HEAD(ifgrouphead, ifg_group);
97 
98 /*
99  * Structure defining a queue for a network interface.
100  */
101 struct	ifqueue {
102 	struct	mbuf *ifq_head;
103 	struct	mbuf *ifq_tail;
104 	int	ifq_len;
105 	int	ifq_maxlen;
106 	int	ifq_drops;
107 	struct	mtx ifq_mtx;
108 };
109 
110 /*
111  * Structure defining a network interface.
112  *
113  * (Would like to call this struct ``if'', but C isn't PL/1.)
114  */
115 
116 struct ifnet {
117 	void	*if_softc;		/* pointer to driver state */
118 	void	*if_l2com;		/* pointer to protocol bits */
119 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
120 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
121 	const char *if_dname;		/* driver name */
122 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
123 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
124 		/*
125 		 * if_addrhead is the list of all addresses associated to
126 		 * an interface.
127 		 * Some code in the kernel assumes that first element
128 		 * of the list has type AF_LINK, and contains sockaddr_dl
129 		 * addresses which store the link-level address and the name
130 		 * of the interface.
131 		 * However, access to the AF_LINK address through this
132 		 * field is deprecated. Use if_addr or ifaddr_byindex() instead.
133 		 */
134 	struct	knlist if_klist;	/* events attached to this if */
135 	int	if_pcount;		/* number of promiscuous listeners */
136 	struct	carp_if *if_carp;	/* carp interface structure */
137 	struct	bpf_if *if_bpf;		/* packet filter structure */
138 	u_short	if_index;		/* numeric abbreviation for this if  */
139 	short	if_timer;		/* time 'til if_watchdog called */
140 	struct  ifvlantrunk *if_vlantrunk; /* pointer to 802.1q data */
141 	int	if_flags;		/* up/down, broadcast, etc. */
142 	int	if_capabilities;	/* interface features & capabilities */
143 	int	if_capenable;		/* enabled features & capabilities */
144 	void	*if_linkmib;		/* link-type-specific MIB data */
145 	size_t	if_linkmiblen;		/* length of above data */
146 	struct	if_data if_data;
147 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
148 	int	if_amcount;		/* number of all-multicast requests */
149 /* procedure handles */
150 	int	(*if_output)		/* output routine (enqueue) */
151 		(struct ifnet *, struct mbuf *, struct sockaddr *,
152 		     struct rtentry *);
153 	void	(*if_input)		/* input routine (from h/w driver) */
154 		(struct ifnet *, struct mbuf *);
155 	void	(*if_start)		/* initiate output routine */
156 		(struct ifnet *);
157 	int	(*if_ioctl)		/* ioctl routine */
158 		(struct ifnet *, u_long, caddr_t);
159 	void	(*if_watchdog)		/* timer routine */
160 		(struct ifnet *);
161 	void	(*if_init)		/* Init routine */
162 		(void *);
163 	int	(*if_resolvemulti)	/* validate/resolve multicast */
164 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
165 	struct	ifaddr	*if_addr;	/* pointer to link-level address */
166 	void	*if_llsoftc;		/* link layer softc */
167 	int	if_drv_flags;		/* driver-managed status flags */
168 	u_int	if_spare_flags2;	/* spare flags 2 */
169 	struct  ifaltq if_snd;		/* output queue (includes altq) */
170 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
171 
172 	void	*if_bridge;		/* bridge glue */
173 
174 	struct	label *if_label;	/* interface MAC label */
175 
176 	/* these are only used by IPv6 */
177 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
178 	void	*if_afdata[AF_MAX];
179 	int	if_afdata_initialized;
180 	struct	rwlock if_afdata_lock;
181 	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
182 	struct	task if_linktask;	/* task for link change events */
183 	struct	mtx if_addr_mtx;	/* mutex to protect address lists */
184 
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 	void	*if_pspare[8];		/* TOE 3; vimage 3; general use 4 */
191 	void	(*if_qflush)		/* flush any queues */
192 		(struct ifnet *);
193 	int	(*if_transmit)	/* initiate output routine */
194 		(struct ifnet *, struct mbuf *);
195 	int	if_ispare[2];		/* general use 2 */
196 };
197 
198 typedef void if_init_f_t(void *);
199 
200 /*
201  * XXX These aliases are terribly dangerous because they could apply
202  * to anything.
203  */
204 #define	if_mtu		if_data.ifi_mtu
205 #define	if_type		if_data.ifi_type
206 #define if_physical	if_data.ifi_physical
207 #define	if_addrlen	if_data.ifi_addrlen
208 #define	if_hdrlen	if_data.ifi_hdrlen
209 #define	if_metric	if_data.ifi_metric
210 #define	if_link_state	if_data.ifi_link_state
211 #define	if_baudrate	if_data.ifi_baudrate
212 #define	if_hwassist	if_data.ifi_hwassist
213 #define	if_ipackets	if_data.ifi_ipackets
214 #define	if_ierrors	if_data.ifi_ierrors
215 #define	if_opackets	if_data.ifi_opackets
216 #define	if_oerrors	if_data.ifi_oerrors
217 #define	if_collisions	if_data.ifi_collisions
218 #define	if_ibytes	if_data.ifi_ibytes
219 #define	if_obytes	if_data.ifi_obytes
220 #define	if_imcasts	if_data.ifi_imcasts
221 #define	if_omcasts	if_data.ifi_omcasts
222 #define	if_iqdrops	if_data.ifi_iqdrops
223 #define	if_noproto	if_data.ifi_noproto
224 #define	if_lastchange	if_data.ifi_lastchange
225 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
226 
227 /* for compatibility with other BSDs */
228 #define	if_addrlist	if_addrhead
229 #define	if_list		if_link
230 #define	if_name(ifp)	((ifp)->if_xname)
231 
232 /*
233  * Locks for address lists on the network interface.
234  */
235 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
236 				    "if_addr_mtx", NULL, MTX_DEF)
237 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
238 #define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
239 #define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
240 #define	IF_ADDR_LOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
241 
242 /*
243  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
244  * are queues of messages stored on ifqueue structures
245  * (defined above).  Entries are added to and deleted from these structures
246  * by these macros, which should be called with ipl raised to splimp().
247  */
248 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
249 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
250 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
251 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
252 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
253 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
254 
255 #define	_IF_ENQUEUE(ifq, m) do { 				\
256 	(m)->m_nextpkt = NULL;					\
257 	if ((ifq)->ifq_tail == NULL) 				\
258 		(ifq)->ifq_head = m; 				\
259 	else 							\
260 		(ifq)->ifq_tail->m_nextpkt = m; 		\
261 	(ifq)->ifq_tail = m; 					\
262 	(ifq)->ifq_len++; 					\
263 } while (0)
264 
265 #define IF_ENQUEUE(ifq, m) do {					\
266 	IF_LOCK(ifq); 						\
267 	_IF_ENQUEUE(ifq, m); 					\
268 	IF_UNLOCK(ifq); 					\
269 } while (0)
270 
271 #define	_IF_PREPEND(ifq, m) do {				\
272 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
273 	if ((ifq)->ifq_tail == NULL) 				\
274 		(ifq)->ifq_tail = (m); 				\
275 	(ifq)->ifq_head = (m); 					\
276 	(ifq)->ifq_len++; 					\
277 } while (0)
278 
279 #define IF_PREPEND(ifq, m) do {		 			\
280 	IF_LOCK(ifq); 						\
281 	_IF_PREPEND(ifq, m); 					\
282 	IF_UNLOCK(ifq); 					\
283 } while (0)
284 
285 #define	_IF_DEQUEUE(ifq, m) do { 				\
286 	(m) = (ifq)->ifq_head; 					\
287 	if (m) { 						\
288 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
289 			(ifq)->ifq_tail = NULL; 		\
290 		(m)->m_nextpkt = NULL; 				\
291 		(ifq)->ifq_len--; 				\
292 	} 							\
293 } while (0)
294 
295 #define IF_DEQUEUE(ifq, m) do { 				\
296 	IF_LOCK(ifq); 						\
297 	_IF_DEQUEUE(ifq, m); 					\
298 	IF_UNLOCK(ifq); 					\
299 } while (0)
300 
301 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
302 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
303 
304 #define _IF_DRAIN(ifq) do { 					\
305 	struct mbuf *m; 					\
306 	for (;;) { 						\
307 		_IF_DEQUEUE(ifq, m); 				\
308 		if (m == NULL) 					\
309 			break; 					\
310 		m_freem(m); 					\
311 	} 							\
312 } while (0)
313 
314 #define IF_DRAIN(ifq) do {					\
315 	IF_LOCK(ifq);						\
316 	_IF_DRAIN(ifq);						\
317 	IF_UNLOCK(ifq);						\
318 } while(0)
319 
320 #ifdef _KERNEL
321 /* interface address change event */
322 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
323 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
324 /* new interface arrival event */
325 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
326 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
327 /* interface departure event */
328 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
329 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
330 
331 /*
332  * interface groups
333  */
334 struct ifg_group {
335 	char				 ifg_group[IFNAMSIZ];
336 	u_int				 ifg_refcnt;
337 	void				*ifg_pf_kif;
338 	TAILQ_HEAD(, ifg_member)	 ifg_members;
339 	TAILQ_ENTRY(ifg_group)		 ifg_next;
340 };
341 
342 struct ifg_member {
343 	TAILQ_ENTRY(ifg_member)	 ifgm_next;
344 	struct ifnet		*ifgm_ifp;
345 };
346 
347 struct ifg_list {
348 	struct ifg_group	*ifgl_group;
349 	TAILQ_ENTRY(ifg_list)	 ifgl_next;
350 };
351 
352 /* group attach event */
353 typedef void (*group_attach_event_handler_t)(void *, struct ifg_group *);
354 EVENTHANDLER_DECLARE(group_attach_event, group_attach_event_handler_t);
355 /* group detach event */
356 typedef void (*group_detach_event_handler_t)(void *, struct ifg_group *);
357 EVENTHANDLER_DECLARE(group_detach_event, group_detach_event_handler_t);
358 /* group change event */
359 typedef void (*group_change_event_handler_t)(void *, const char *);
360 EVENTHANDLER_DECLARE(group_change_event, group_change_event_handler_t);
361 
362 #define	IF_AFDATA_LOCK_INIT(ifp)	\
363 	rw_init(&(ifp)->if_afdata_lock, "if_afdata")
364 
365 #define	IF_AFDATA_WLOCK(ifp)	rw_wlock(&(ifp)->if_afdata_lock)
366 #define	IF_AFDATA_RLOCK(ifp)	rw_rlock(&(ifp)->if_afdata_lock)
367 #define	IF_AFDATA_WUNLOCK(ifp)	rw_wunlock(&(ifp)->if_afdata_lock)
368 #define	IF_AFDATA_RUNLOCK(ifp)	rw_runlock(&(ifp)->if_afdata_lock)
369 #define	IF_AFDATA_LOCK(ifp)	IF_AFDATA_WLOCK(ifp)
370 #define	IF_AFDATA_UNLOCK(ifp)	IF_AFDATA_WUNLOCK(ifp)
371 #define	IF_AFDATA_TRYLOCK(ifp)	rw_try_wlock(&(ifp)->if_afdata_lock)
372 #define	IF_AFDATA_DESTROY(ifp)	rw_destroy(&(ifp)->if_afdata_lock)
373 
374 #define	IF_AFDATA_LOCK_ASSERT(ifp)	rw_assert(&(ifp)->if_afdata_lock, RA_LOCKED)
375 #define	IF_AFDATA_UNLOCK_ASSERT(ifp)	rw_assert(&(ifp)->if_afdata_lock, RA_UNLOCKED)
376 
377 #define	IFF_LOCKGIANT(ifp) do {						\
378 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
379 		mtx_lock(&Giant);					\
380 } while (0)
381 
382 #define	IFF_UNLOCKGIANT(ifp) do {					\
383 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
384 		mtx_unlock(&Giant);					\
385 } while (0)
386 
387 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
388 	    int adjust);
389 #define	IF_HANDOFF(ifq, m, ifp)			\
390 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
391 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
392 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
393 
394 void	if_start(struct ifnet *);
395 
396 #define	IFQ_ENQUEUE(ifq, m, err)					\
397 do {									\
398 	IF_LOCK(ifq);							\
399 	if (ALTQ_IS_ENABLED(ifq))					\
400 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
401 	else {								\
402 		if (_IF_QFULL(ifq)) {					\
403 			m_freem(m);					\
404 			(err) = ENOBUFS;				\
405 		} else {						\
406 			_IF_ENQUEUE(ifq, m);				\
407 			(err) = 0;					\
408 		}							\
409 	}								\
410 	if (err)							\
411 		(ifq)->ifq_drops++;					\
412 	IF_UNLOCK(ifq);							\
413 } while (0)
414 
415 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
416 do {									\
417 	if (TBR_IS_ENABLED(ifq))					\
418 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
419 	else if (ALTQ_IS_ENABLED(ifq))					\
420 		ALTQ_DEQUEUE(ifq, m);					\
421 	else								\
422 		_IF_DEQUEUE(ifq, m);					\
423 } while (0)
424 
425 #define	IFQ_DEQUEUE(ifq, m)						\
426 do {									\
427 	IF_LOCK(ifq);							\
428 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
429 	IF_UNLOCK(ifq);							\
430 } while (0)
431 
432 #define	IFQ_POLL_NOLOCK(ifq, m)						\
433 do {									\
434 	if (TBR_IS_ENABLED(ifq))					\
435 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
436 	else if (ALTQ_IS_ENABLED(ifq))					\
437 		ALTQ_POLL(ifq, m);					\
438 	else								\
439 		_IF_POLL(ifq, m);					\
440 } while (0)
441 
442 #define	IFQ_POLL(ifq, m)						\
443 do {									\
444 	IF_LOCK(ifq);							\
445 	IFQ_POLL_NOLOCK(ifq, m);					\
446 	IF_UNLOCK(ifq);							\
447 } while (0)
448 
449 #define	IFQ_PURGE_NOLOCK(ifq)						\
450 do {									\
451 	if (ALTQ_IS_ENABLED(ifq)) {					\
452 		ALTQ_PURGE(ifq);					\
453 	} else								\
454 		_IF_DRAIN(ifq);						\
455 } while (0)
456 
457 #define	IFQ_PURGE(ifq)							\
458 do {									\
459 	IF_LOCK(ifq);							\
460 	IFQ_PURGE_NOLOCK(ifq);						\
461 	IF_UNLOCK(ifq);							\
462 } while (0)
463 
464 #define	IFQ_SET_READY(ifq)						\
465 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
466 
467 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
468 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
469 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
470 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
471 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
472 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
473 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
474 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
475 
476 /*
477  * The IFF_DRV_OACTIVE test should really occur in the device driver, not in
478  * the handoff logic, as that flag is locked by the device driver.
479  */
480 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
481 do {									\
482 	int len;							\
483 	short mflags;							\
484 									\
485 	len = (m)->m_pkthdr.len;					\
486 	mflags = (m)->m_flags;						\
487 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
488 	if ((err) == 0) {						\
489 		(ifp)->if_obytes += len + (adj);			\
490 		if (mflags & M_MCAST)					\
491 			(ifp)->if_omcasts++;				\
492 		if (((ifp)->if_drv_flags & IFF_DRV_OACTIVE) == 0)	\
493 			if_start(ifp);					\
494 	}								\
495 } while (0)
496 
497 #define	IFQ_HANDOFF(ifp, m, err)					\
498 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
499 
500 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
501 do {									\
502 	(m) = (ifq)->ifq_drv_head;					\
503 	if (m) {							\
504 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
505 			(ifq)->ifq_drv_tail = NULL;			\
506 		(m)->m_nextpkt = NULL;					\
507 		(ifq)->ifq_drv_len--;					\
508 	} else {							\
509 		IFQ_LOCK(ifq);						\
510 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
511 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
512 			struct mbuf *m0;				\
513 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
514 			if (m0 == NULL)					\
515 				break;					\
516 			m0->m_nextpkt = NULL;				\
517 			if ((ifq)->ifq_drv_tail == NULL)		\
518 				(ifq)->ifq_drv_head = m0;		\
519 			else						\
520 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
521 			(ifq)->ifq_drv_tail = m0;			\
522 			(ifq)->ifq_drv_len++;				\
523 		}							\
524 		IFQ_UNLOCK(ifq);					\
525 	}								\
526 } while (0)
527 
528 #define	IFQ_DRV_PREPEND(ifq, m)						\
529 do {									\
530 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
531 	if ((ifq)->ifq_drv_tail == NULL)				\
532 		(ifq)->ifq_drv_tail = (m);				\
533 	(ifq)->ifq_drv_head = (m);					\
534 	(ifq)->ifq_drv_len++;						\
535 } while (0)
536 
537 #define	IFQ_DRV_IS_EMPTY(ifq)						\
538 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
539 
540 #define	IFQ_DRV_PURGE(ifq)						\
541 do {									\
542 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
543 	while((m = n) != NULL) {					\
544 		n = m->m_nextpkt;					\
545 		m_freem(m);						\
546 	}								\
547 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
548 	(ifq)->ifq_drv_len = 0;						\
549 	IFQ_PURGE(ifq);							\
550 } while (0)
551 
552 #ifdef _KERNEL
553 static __inline void
554 drbr_stats_update(struct ifnet *ifp, int len, int mflags)
555 {
556 
557 	ifp->if_obytes += len;
558 	if (mflags & M_MCAST)
559 		ifp->if_omcasts++;
560 }
561 
562 static __inline int
563 drbr_enqueue(struct ifnet *ifp, struct buf_ring *br, struct mbuf *m)
564 {
565 	int error = 0;
566 	int len = m->m_pkthdr.len;
567 	int mflags = m->m_flags;
568 
569 	if ((error = buf_ring_enqueue(br, m)) == ENOBUFS) {
570 		br->br_drops++;
571 		_IF_DROP(&ifp->if_snd);
572 		m_freem(m);
573 	} else
574 		drbr_stats_update(ifp, len, mflags);
575 
576 	return (error);
577 }
578 
579 static __inline void
580 drbr_free(struct buf_ring *br, struct malloc_type *type)
581 {
582 	struct mbuf *m;
583 
584 	while ((m = buf_ring_dequeue_sc(br)) != NULL)
585 		m_freem(m);
586 
587 	buf_ring_free(br, type);
588 }
589 #endif
590 
591 /*
592  * 72 was chosen below because it is the size of a TCP/IP
593  * header (40) + the minimum mss (32).
594  */
595 #define	IF_MINMTU	72
596 #define	IF_MAXMTU	65535
597 
598 #endif /* _KERNEL */
599 
600 /*
601  * The ifaddr structure contains information about one address
602  * of an interface.  They are maintained by the different address families,
603  * are allocated and attached when an address is set, and are linked
604  * together so all addresses for an interface can be located.
605  *
606  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
607  * chunk of malloc'ed memory, where we store the three addresses
608  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
609  */
610 struct ifaddr {
611 	struct	sockaddr *ifa_addr;	/* address of interface */
612 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
613 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
614 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
615 	struct	if_data if_data;	/* not all members are meaningful */
616 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
617 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
618 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
619 		(int, struct rtentry *, struct rt_addrinfo *);
620 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
621 	u_int	ifa_refcnt;		/* references to this structure */
622 	int	ifa_metric;		/* cost of going out this interface */
623 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
624 		(struct ifaddr *, struct sockaddr *);
625 	struct mtx ifa_mtx;
626 };
627 #define	IFA_ROUTE	RTF_UP		/* route installed */
628 
629 /* for compatibility with other BSDs */
630 #define	ifa_list	ifa_link
631 
632 #define	IFA_LOCK_INIT(ifa)	\
633     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
634 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
635 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
636 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
637 
638 /*
639  * The prefix structure contains information about one prefix
640  * of an interface.  They are maintained by the different address families,
641  * are allocated and attached when a prefix or an address is set,
642  * and are linked together so all prefixes for an interface can be located.
643  */
644 struct ifprefix {
645 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
646 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
647 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
648 	u_char	ifpr_plen;		/* prefix length in bits */
649 	u_char	ifpr_type;		/* protocol dependent prefix type */
650 };
651 
652 /*
653  * Multicast address structure.  This is analogous to the ifaddr
654  * structure except that it keeps track of multicast addresses.
655  */
656 struct ifmultiaddr {
657 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
658 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
659 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
660 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
661 	u_int	ifma_refcount;		/* reference count */
662 	void	*ifma_protospec;	/* protocol-specific state, if any */
663 	struct	ifmultiaddr *ifma_llifma; /* pointer to ifma for ifma_lladdr */
664 };
665 
666 #ifdef _KERNEL
667 #define	IFAFREE(ifa)					\
668 	do {						\
669 		IFA_LOCK(ifa);				\
670 		KASSERT((ifa)->ifa_refcnt > 0,		\
671 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
672 		if (--(ifa)->ifa_refcnt == 0) {		\
673 			IFA_DESTROY(ifa);		\
674 			free(ifa, M_IFADDR);		\
675 		} else 					\
676 			IFA_UNLOCK(ifa);		\
677 	} while (0)
678 
679 #define IFAREF(ifa)					\
680 	do {						\
681 		IFA_LOCK(ifa);				\
682 		++(ifa)->ifa_refcnt;			\
683 		IFA_UNLOCK(ifa);			\
684 	} while (0)
685 
686 extern	struct rwlock ifnet_lock;
687 #define	IFNET_LOCK_INIT() \
688    rw_init_flags(&ifnet_lock, "ifnet",  RW_RECURSE)
689 #define	IFNET_WLOCK()		rw_wlock(&ifnet_lock)
690 #define	IFNET_WUNLOCK()		rw_wunlock(&ifnet_lock)
691 #define	IFNET_WLOCK_ASSERT()	rw_assert(&ifnet_lock, RA_LOCKED)
692 #define	IFNET_RLOCK()		rw_rlock(&ifnet_lock)
693 #define	IFNET_RUNLOCK()		rw_runlock(&ifnet_lock)
694 
695 struct ifindex_entry {
696 	struct	ifnet *ife_ifnet;
697 	struct cdev *ife_dev;
698 };
699 
700 struct ifnet	*ifnet_byindex(u_short idx);
701 
702 /*
703  * Given the index, ifaddr_byindex() returns the one and only
704  * link-level ifaddr for the interface. You are not supposed to use
705  * it to traverse the list of addresses associated to the interface.
706  */
707 struct ifaddr	*ifaddr_byindex(u_short idx);
708 struct cdev	*ifdev_byindex(u_short idx);
709 
710 #ifdef VIMAGE_GLOBALS
711 extern	struct ifnethead ifnet;
712 extern	struct ifnet *loif;	/* first loopback interface */
713 extern	int if_index;
714 #endif
715 extern	int ifqmaxlen;
716 
717 int	if_addgroup(struct ifnet *, const char *);
718 int	if_delgroup(struct ifnet *, const char *);
719 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
720 int	if_allmulti(struct ifnet *, int);
721 struct	ifnet* if_alloc(u_char);
722 void	if_attach(struct ifnet *);
723 int	if_delmulti(struct ifnet *, struct sockaddr *);
724 void	if_delmulti_ifma(struct ifmultiaddr *);
725 void	if_detach(struct ifnet *);
726 void	if_purgeaddrs(struct ifnet *);
727 void	if_purgemaddrs(struct ifnet *);
728 void	if_down(struct ifnet *);
729 struct ifmultiaddr *
730 	if_findmulti(struct ifnet *, struct sockaddr *);
731 void	if_free(struct ifnet *);
732 void	if_free_type(struct ifnet *, u_char);
733 void	if_initname(struct ifnet *, const char *, int);
734 void	if_link_state_change(struct ifnet *, int);
735 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
736 int	if_setlladdr(struct ifnet *, const u_char *, int);
737 void	if_up(struct ifnet *);
738 /*void	ifinit(void);*/ /* declared in systm.h for main() */
739 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
740 int	ifpromisc(struct ifnet *, int);
741 struct	ifnet *ifunit(const char *);
742 
743 void	ifq_attach(struct ifaltq *, struct ifnet *ifp);
744 void	ifq_detach(struct ifaltq *);
745 
746 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
747 struct	ifaddr *ifa_ifwithbroadaddr(struct sockaddr *);
748 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
749 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
750 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
751 struct	ifaddr *ifa_ifwithroute_fib(int, struct sockaddr *, struct sockaddr *, u_int);
752 
753 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
754 
755 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
756 
757 typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
758 typedef	void if_com_free_t(void *com, u_char type);
759 void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
760 void	if_deregister_com_alloc(u_char type);
761 
762 #define IF_LLADDR(ifp)							\
763     LLADDR((struct sockaddr_dl *)((ifp)->if_addr->ifa_addr))
764 
765 #ifdef DEVICE_POLLING
766 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS };
767 
768 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
769 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
770 int    ether_poll_deregister(struct ifnet *ifp);
771 #endif /* DEVICE_POLLING */
772 
773 #endif /* _KERNEL */
774 
775 #endif /* !_NET_IF_VAR_H_ */
776