xref: /freebsd/sys/net/if_var.h (revision 8655c70597b0e0918c82114b1186df5669b83eb6)
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 	void	(*if_qflush)		/* flush any queues */
166 		(struct ifnet *);
167 	int	(*if_transmit)		/* initiate output routine */
168 		(struct ifnet *, struct mbuf *);
169 	struct	ifaddr	*if_addr;	/* pointer to link-level address */
170 	void	*if_llsoftc;		/* link layer softc */
171 	int	if_drv_flags;		/* driver-managed status flags */
172 	struct  ifaltq if_snd;		/* output queue (includes altq) */
173 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
174 
175 	void	*if_bridge;		/* bridge glue */
176 
177 	struct	label *if_label;	/* interface MAC label */
178 
179 	/* these are only used by IPv6 */
180 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
181 	void	*if_afdata[AF_MAX];
182 	int	if_afdata_initialized;
183 	struct	rwlock if_afdata_lock;
184 	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
185 	struct	task if_linktask;	/* task for link change events */
186 	struct	mtx if_addr_mtx;	/* mutex to protect address lists */
187 
188 	LIST_ENTRY(ifnet) if_clones;	/* interfaces of a cloner */
189 	TAILQ_HEAD(, ifg_list) if_groups; /* linked list of groups per if */
190 					/* protected by if_addr_mtx */
191 	void	*if_pf_kif;
192 	void	*if_lagg;		/* lagg glue */
193 
194 	/*
195 	 * Spare fields are added so that we can modify sensitive data
196 	 * structures without changing the kernel binary interface, and must
197 	 * be used with care where binary compatibility is required.
198 	 */
199 	void	*if_pspare[8];
200 	int	if_ispare[4];
201 };
202 
203 typedef void if_init_f_t(void *);
204 
205 /*
206  * XXX These aliases are terribly dangerous because they could apply
207  * to anything.
208  */
209 #define	if_mtu		if_data.ifi_mtu
210 #define	if_type		if_data.ifi_type
211 #define if_physical	if_data.ifi_physical
212 #define	if_addrlen	if_data.ifi_addrlen
213 #define	if_hdrlen	if_data.ifi_hdrlen
214 #define	if_metric	if_data.ifi_metric
215 #define	if_link_state	if_data.ifi_link_state
216 #define	if_baudrate	if_data.ifi_baudrate
217 #define	if_hwassist	if_data.ifi_hwassist
218 #define	if_ipackets	if_data.ifi_ipackets
219 #define	if_ierrors	if_data.ifi_ierrors
220 #define	if_opackets	if_data.ifi_opackets
221 #define	if_oerrors	if_data.ifi_oerrors
222 #define	if_collisions	if_data.ifi_collisions
223 #define	if_ibytes	if_data.ifi_ibytes
224 #define	if_obytes	if_data.ifi_obytes
225 #define	if_imcasts	if_data.ifi_imcasts
226 #define	if_omcasts	if_data.ifi_omcasts
227 #define	if_iqdrops	if_data.ifi_iqdrops
228 #define	if_noproto	if_data.ifi_noproto
229 #define	if_lastchange	if_data.ifi_lastchange
230 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
231 
232 /* for compatibility with other BSDs */
233 #define	if_addrlist	if_addrhead
234 #define	if_list		if_link
235 #define	if_name(ifp)	((ifp)->if_xname)
236 
237 /*
238  * Locks for address lists on the network interface.
239  */
240 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
241 				    "if_addr_mtx", NULL, MTX_DEF)
242 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
243 #define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
244 #define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
245 #define	IF_ADDR_LOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
246 
247 /*
248  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
249  * are queues of messages stored on ifqueue structures
250  * (defined above).  Entries are added to and deleted from these structures
251  * by these macros, which should be called with ipl raised to splimp().
252  */
253 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
254 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
255 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
256 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
257 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
258 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
259 
260 #define	_IF_ENQUEUE(ifq, m) do { 				\
261 	(m)->m_nextpkt = NULL;					\
262 	if ((ifq)->ifq_tail == NULL) 				\
263 		(ifq)->ifq_head = m; 				\
264 	else 							\
265 		(ifq)->ifq_tail->m_nextpkt = m; 		\
266 	(ifq)->ifq_tail = m; 					\
267 	(ifq)->ifq_len++; 					\
268 } while (0)
269 
270 #define IF_ENQUEUE(ifq, m) do {					\
271 	IF_LOCK(ifq); 						\
272 	_IF_ENQUEUE(ifq, m); 					\
273 	IF_UNLOCK(ifq); 					\
274 } while (0)
275 
276 #define	_IF_PREPEND(ifq, m) do {				\
277 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
278 	if ((ifq)->ifq_tail == NULL) 				\
279 		(ifq)->ifq_tail = (m); 				\
280 	(ifq)->ifq_head = (m); 					\
281 	(ifq)->ifq_len++; 					\
282 } while (0)
283 
284 #define IF_PREPEND(ifq, m) do {		 			\
285 	IF_LOCK(ifq); 						\
286 	_IF_PREPEND(ifq, m); 					\
287 	IF_UNLOCK(ifq); 					\
288 } while (0)
289 
290 #define	_IF_DEQUEUE(ifq, m) do { 				\
291 	(m) = (ifq)->ifq_head; 					\
292 	if (m) { 						\
293 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
294 			(ifq)->ifq_tail = NULL; 		\
295 		(m)->m_nextpkt = NULL; 				\
296 		(ifq)->ifq_len--; 				\
297 	} 							\
298 } while (0)
299 
300 #define IF_DEQUEUE(ifq, m) do { 				\
301 	IF_LOCK(ifq); 						\
302 	_IF_DEQUEUE(ifq, m); 					\
303 	IF_UNLOCK(ifq); 					\
304 } while (0)
305 
306 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
307 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
308 
309 #define _IF_DRAIN(ifq) do { 					\
310 	struct mbuf *m; 					\
311 	for (;;) { 						\
312 		_IF_DEQUEUE(ifq, m); 				\
313 		if (m == NULL) 					\
314 			break; 					\
315 		m_freem(m); 					\
316 	} 							\
317 } while (0)
318 
319 #define IF_DRAIN(ifq) do {					\
320 	IF_LOCK(ifq);						\
321 	_IF_DRAIN(ifq);						\
322 	IF_UNLOCK(ifq);						\
323 } while(0)
324 
325 #ifdef _KERNEL
326 /* interface address change event */
327 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
328 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
329 /* new interface arrival event */
330 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
331 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
332 /* interface departure event */
333 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
334 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
335 
336 /*
337  * interface groups
338  */
339 struct ifg_group {
340 	char				 ifg_group[IFNAMSIZ];
341 	u_int				 ifg_refcnt;
342 	void				*ifg_pf_kif;
343 	TAILQ_HEAD(, ifg_member)	 ifg_members;
344 	TAILQ_ENTRY(ifg_group)		 ifg_next;
345 };
346 
347 struct ifg_member {
348 	TAILQ_ENTRY(ifg_member)	 ifgm_next;
349 	struct ifnet		*ifgm_ifp;
350 };
351 
352 struct ifg_list {
353 	struct ifg_group	*ifgl_group;
354 	TAILQ_ENTRY(ifg_list)	 ifgl_next;
355 };
356 
357 /* group attach event */
358 typedef void (*group_attach_event_handler_t)(void *, struct ifg_group *);
359 EVENTHANDLER_DECLARE(group_attach_event, group_attach_event_handler_t);
360 /* group detach event */
361 typedef void (*group_detach_event_handler_t)(void *, struct ifg_group *);
362 EVENTHANDLER_DECLARE(group_detach_event, group_detach_event_handler_t);
363 /* group change event */
364 typedef void (*group_change_event_handler_t)(void *, const char *);
365 EVENTHANDLER_DECLARE(group_change_event, group_change_event_handler_t);
366 
367 #define	IF_AFDATA_LOCK_INIT(ifp)	\
368 	rw_init(&(ifp)->if_afdata_lock, "if_afdata")
369 
370 #define	IF_AFDATA_WLOCK(ifp)	rw_wlock(&(ifp)->if_afdata_lock)
371 #define	IF_AFDATA_RLOCK(ifp)	rw_rlock(&(ifp)->if_afdata_lock)
372 #define	IF_AFDATA_WUNLOCK(ifp)	rw_wunlock(&(ifp)->if_afdata_lock)
373 #define	IF_AFDATA_RUNLOCK(ifp)	rw_runlock(&(ifp)->if_afdata_lock)
374 #define	IF_AFDATA_LOCK(ifp)	IF_AFDATA_WLOCK(ifp)
375 #define	IF_AFDATA_UNLOCK(ifp)	IF_AFDATA_WUNLOCK(ifp)
376 #define	IF_AFDATA_TRYLOCK(ifp)	rw_try_wlock(&(ifp)->if_afdata_lock)
377 #define	IF_AFDATA_DESTROY(ifp)	rw_destroy(&(ifp)->if_afdata_lock)
378 
379 #define	IF_AFDATA_LOCK_ASSERT(ifp)	rw_assert(&(ifp)->if_afdata_lock, RA_LOCKED)
380 #define	IF_AFDATA_UNLOCK_ASSERT(ifp)	rw_assert(&(ifp)->if_afdata_lock, RA_UNLOCKED)
381 
382 #define	IFF_LOCKGIANT(ifp) do {						\
383 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
384 		mtx_lock(&Giant);					\
385 } while (0)
386 
387 #define	IFF_UNLOCKGIANT(ifp) do {					\
388 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
389 		mtx_unlock(&Giant);					\
390 } while (0)
391 
392 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
393 	    int adjust);
394 #define	IF_HANDOFF(ifq, m, ifp)			\
395 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
396 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
397 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
398 
399 void	if_start(struct ifnet *);
400 
401 #define	IFQ_ENQUEUE(ifq, m, err)					\
402 do {									\
403 	IF_LOCK(ifq);							\
404 	if (ALTQ_IS_ENABLED(ifq))					\
405 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
406 	else {								\
407 		if (_IF_QFULL(ifq)) {					\
408 			m_freem(m);					\
409 			(err) = ENOBUFS;				\
410 		} else {						\
411 			_IF_ENQUEUE(ifq, m);				\
412 			(err) = 0;					\
413 		}							\
414 	}								\
415 	if (err)							\
416 		(ifq)->ifq_drops++;					\
417 	IF_UNLOCK(ifq);							\
418 } while (0)
419 
420 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
421 do {									\
422 	if (TBR_IS_ENABLED(ifq))					\
423 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
424 	else if (ALTQ_IS_ENABLED(ifq))					\
425 		ALTQ_DEQUEUE(ifq, m);					\
426 	else								\
427 		_IF_DEQUEUE(ifq, m);					\
428 } while (0)
429 
430 #define	IFQ_DEQUEUE(ifq, m)						\
431 do {									\
432 	IF_LOCK(ifq);							\
433 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
434 	IF_UNLOCK(ifq);							\
435 } while (0)
436 
437 #define	IFQ_POLL_NOLOCK(ifq, m)						\
438 do {									\
439 	if (TBR_IS_ENABLED(ifq))					\
440 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
441 	else if (ALTQ_IS_ENABLED(ifq))					\
442 		ALTQ_POLL(ifq, m);					\
443 	else								\
444 		_IF_POLL(ifq, m);					\
445 } while (0)
446 
447 #define	IFQ_POLL(ifq, m)						\
448 do {									\
449 	IF_LOCK(ifq);							\
450 	IFQ_POLL_NOLOCK(ifq, m);					\
451 	IF_UNLOCK(ifq);							\
452 } while (0)
453 
454 #define	IFQ_PURGE_NOLOCK(ifq)						\
455 do {									\
456 	if (ALTQ_IS_ENABLED(ifq)) {					\
457 		ALTQ_PURGE(ifq);					\
458 	} else								\
459 		_IF_DRAIN(ifq);						\
460 } while (0)
461 
462 #define	IFQ_PURGE(ifq)							\
463 do {									\
464 	IF_LOCK(ifq);							\
465 	IFQ_PURGE_NOLOCK(ifq);						\
466 	IF_UNLOCK(ifq);							\
467 } while (0)
468 
469 #define	IFQ_SET_READY(ifq)						\
470 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
471 
472 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
473 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
474 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
475 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
476 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
477 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
478 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
479 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
480 
481 /*
482  * The IFF_DRV_OACTIVE test should really occur in the device driver, not in
483  * the handoff logic, as that flag is locked by the device driver.
484  */
485 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
486 do {									\
487 	int len;							\
488 	short mflags;							\
489 									\
490 	len = (m)->m_pkthdr.len;					\
491 	mflags = (m)->m_flags;						\
492 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
493 	if ((err) == 0) {						\
494 		(ifp)->if_obytes += len + (adj);			\
495 		if (mflags & M_MCAST)					\
496 			(ifp)->if_omcasts++;				\
497 		if (((ifp)->if_drv_flags & IFF_DRV_OACTIVE) == 0)	\
498 			if_start(ifp);					\
499 	}								\
500 } while (0)
501 
502 #define	IFQ_HANDOFF(ifp, m, err)					\
503 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
504 
505 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
506 do {									\
507 	(m) = (ifq)->ifq_drv_head;					\
508 	if (m) {							\
509 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
510 			(ifq)->ifq_drv_tail = NULL;			\
511 		(m)->m_nextpkt = NULL;					\
512 		(ifq)->ifq_drv_len--;					\
513 	} else {							\
514 		IFQ_LOCK(ifq);						\
515 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
516 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
517 			struct mbuf *m0;				\
518 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
519 			if (m0 == NULL)					\
520 				break;					\
521 			m0->m_nextpkt = NULL;				\
522 			if ((ifq)->ifq_drv_tail == NULL)		\
523 				(ifq)->ifq_drv_head = m0;		\
524 			else						\
525 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
526 			(ifq)->ifq_drv_tail = m0;			\
527 			(ifq)->ifq_drv_len++;				\
528 		}							\
529 		IFQ_UNLOCK(ifq);					\
530 	}								\
531 } while (0)
532 
533 #define	IFQ_DRV_PREPEND(ifq, m)						\
534 do {									\
535 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
536 	if ((ifq)->ifq_drv_tail == NULL)				\
537 		(ifq)->ifq_drv_tail = (m);				\
538 	(ifq)->ifq_drv_head = (m);					\
539 	(ifq)->ifq_drv_len++;						\
540 } while (0)
541 
542 #define	IFQ_DRV_IS_EMPTY(ifq)						\
543 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
544 
545 #define	IFQ_DRV_PURGE(ifq)						\
546 do {									\
547 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
548 	while((m = n) != NULL) {					\
549 		n = m->m_nextpkt;					\
550 		m_freem(m);						\
551 	}								\
552 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
553 	(ifq)->ifq_drv_len = 0;						\
554 	IFQ_PURGE(ifq);							\
555 } while (0)
556 
557 #ifdef _KERNEL
558 static __inline void
559 drbr_stats_update(struct ifnet *ifp, int len, int mflags)
560 {
561 
562 	ifp->if_obytes += len;
563 	if (mflags & M_MCAST)
564 		ifp->if_omcasts++;
565 }
566 
567 static __inline int
568 drbr_enqueue(struct ifnet *ifp, struct buf_ring *br, struct mbuf *m)
569 {
570 	int error = 0;
571 	int len = m->m_pkthdr.len;
572 	int mflags = m->m_flags;
573 
574 	if ((error = buf_ring_enqueue(br, m)) == ENOBUFS) {
575 		br->br_drops++;
576 		_IF_DROP(&ifp->if_snd);
577 		m_freem(m);
578 	} else
579 		drbr_stats_update(ifp, len, mflags);
580 
581 	return (error);
582 }
583 
584 static __inline void
585 drbr_free(struct buf_ring *br, struct malloc_type *type)
586 {
587 	struct mbuf *m;
588 
589 	while ((m = buf_ring_dequeue_sc(br)) != NULL)
590 		m_freem(m);
591 
592 	buf_ring_free(br, type);
593 }
594 #endif
595 
596 /*
597  * 72 was chosen below because it is the size of a TCP/IP
598  * header (40) + the minimum mss (32).
599  */
600 #define	IF_MINMTU	72
601 #define	IF_MAXMTU	65535
602 
603 #endif /* _KERNEL */
604 
605 /*
606  * The ifaddr structure contains information about one address
607  * of an interface.  They are maintained by the different address families,
608  * are allocated and attached when an address is set, and are linked
609  * together so all addresses for an interface can be located.
610  *
611  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
612  * chunk of malloc'ed memory, where we store the three addresses
613  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
614  */
615 struct ifaddr {
616 	struct	sockaddr *ifa_addr;	/* address of interface */
617 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
618 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
619 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
620 	struct	if_data if_data;	/* not all members are meaningful */
621 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
622 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
623 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
624 		(int, struct rtentry *, struct rt_addrinfo *);
625 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
626 	u_int	ifa_refcnt;		/* references to this structure */
627 	int	ifa_metric;		/* cost of going out this interface */
628 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
629 		(struct ifaddr *, struct sockaddr *);
630 	struct mtx ifa_mtx;
631 };
632 #define	IFA_ROUTE	RTF_UP		/* route installed */
633 
634 /* for compatibility with other BSDs */
635 #define	ifa_list	ifa_link
636 
637 #define	IFA_LOCK_INIT(ifa)	\
638     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
639 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
640 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
641 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
642 
643 /*
644  * The prefix structure contains information about one prefix
645  * of an interface.  They are maintained by the different address families,
646  * are allocated and attached when a prefix or an address is set,
647  * and are linked together so all prefixes for an interface can be located.
648  */
649 struct ifprefix {
650 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
651 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
652 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
653 	u_char	ifpr_plen;		/* prefix length in bits */
654 	u_char	ifpr_type;		/* protocol dependent prefix type */
655 };
656 
657 /*
658  * Multicast address structure.  This is analogous to the ifaddr
659  * structure except that it keeps track of multicast addresses.
660  */
661 struct ifmultiaddr {
662 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
663 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
664 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
665 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
666 	u_int	ifma_refcount;		/* reference count */
667 	void	*ifma_protospec;	/* protocol-specific state, if any */
668 	struct	ifmultiaddr *ifma_llifma; /* pointer to ifma for ifma_lladdr */
669 };
670 
671 #ifdef _KERNEL
672 #define	IFAFREE(ifa)					\
673 	do {						\
674 		IFA_LOCK(ifa);				\
675 		KASSERT((ifa)->ifa_refcnt > 0,		\
676 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
677 		if (--(ifa)->ifa_refcnt == 0) {		\
678 			IFA_DESTROY(ifa);		\
679 			free(ifa, M_IFADDR);		\
680 		} else 					\
681 			IFA_UNLOCK(ifa);		\
682 	} while (0)
683 
684 #define IFAREF(ifa)					\
685 	do {						\
686 		IFA_LOCK(ifa);				\
687 		++(ifa)->ifa_refcnt;			\
688 		IFA_UNLOCK(ifa);			\
689 	} while (0)
690 
691 extern	struct rwlock ifnet_lock;
692 #define	IFNET_LOCK_INIT() \
693    rw_init_flags(&ifnet_lock, "ifnet",  RW_RECURSE)
694 #define	IFNET_WLOCK()		rw_wlock(&ifnet_lock)
695 #define	IFNET_WUNLOCK()		rw_wunlock(&ifnet_lock)
696 #define	IFNET_WLOCK_ASSERT()	rw_assert(&ifnet_lock, RA_LOCKED)
697 #define	IFNET_RLOCK()		rw_rlock(&ifnet_lock)
698 #define	IFNET_RUNLOCK()		rw_runlock(&ifnet_lock)
699 
700 struct ifindex_entry {
701 	struct	ifnet *ife_ifnet;
702 	struct cdev *ife_dev;
703 };
704 
705 struct ifnet	*ifnet_byindex(u_short idx);
706 
707 /*
708  * Given the index, ifaddr_byindex() returns the one and only
709  * link-level ifaddr for the interface. You are not supposed to use
710  * it to traverse the list of addresses associated to the interface.
711  */
712 struct ifaddr	*ifaddr_byindex(u_short idx);
713 struct cdev	*ifdev_byindex(u_short idx);
714 
715 #ifdef VIMAGE_GLOBALS
716 extern	struct ifnethead ifnet;
717 extern	struct ifnet *loif;	/* first loopback interface */
718 extern	int if_index;
719 #endif
720 extern	int ifqmaxlen;
721 
722 int	if_addgroup(struct ifnet *, const char *);
723 int	if_delgroup(struct ifnet *, const char *);
724 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
725 int	if_allmulti(struct ifnet *, int);
726 struct	ifnet* if_alloc(u_char);
727 void	if_attach(struct ifnet *);
728 int	if_delmulti(struct ifnet *, struct sockaddr *);
729 void	if_delmulti_ifma(struct ifmultiaddr *);
730 void	if_detach(struct ifnet *);
731 void	if_purgeaddrs(struct ifnet *);
732 void	if_purgemaddrs(struct ifnet *);
733 void	if_down(struct ifnet *);
734 struct ifmultiaddr *
735 	if_findmulti(struct ifnet *, struct sockaddr *);
736 void	if_free(struct ifnet *);
737 void	if_free_type(struct ifnet *, u_char);
738 void	if_initname(struct ifnet *, const char *, int);
739 void	if_link_state_change(struct ifnet *, int);
740 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
741 int	if_setlladdr(struct ifnet *, const u_char *, int);
742 void	if_up(struct ifnet *);
743 /*void	ifinit(void);*/ /* declared in systm.h for main() */
744 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
745 int	ifpromisc(struct ifnet *, int);
746 struct	ifnet *ifunit(const char *);
747 
748 void	ifq_attach(struct ifaltq *, struct ifnet *ifp);
749 void	ifq_detach(struct ifaltq *);
750 
751 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
752 struct	ifaddr *ifa_ifwithbroadaddr(struct sockaddr *);
753 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
754 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
755 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
756 struct	ifaddr *ifa_ifwithroute_fib(int, struct sockaddr *, struct sockaddr *, u_int);
757 
758 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
759 
760 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
761 
762 typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
763 typedef	void if_com_free_t(void *com, u_char type);
764 void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
765 void	if_deregister_com_alloc(u_char type);
766 
767 #define IF_LLADDR(ifp)							\
768     LLADDR((struct sockaddr_dl *)((ifp)->if_addr->ifa_addr))
769 
770 #ifdef DEVICE_POLLING
771 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS };
772 
773 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
774 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
775 int    ether_poll_deregister(struct ifnet *ifp);
776 #endif /* DEVICE_POLLING */
777 
778 #endif /* _KERNEL */
779 
780 #endif /* !_NET_IF_VAR_H_ */
781