xref: /freebsd/sys/net/if_var.h (revision c0020399a650364d0134f79f3fa319f84064372d)
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 struct	route;
74 #endif
75 
76 #include <sys/queue.h>		/* get TAILQ macros */
77 
78 #ifdef _KERNEL
79 #include <sys/mbuf.h>
80 #include <sys/eventhandler.h>
81 #include <sys/buf_ring.h>
82 #endif /* _KERNEL */
83 #include <sys/lock.h>		/* XXX */
84 #include <sys/mutex.h>		/* XXX */
85 #include <sys/rwlock.h>		/* XXX */
86 #include <sys/event.h>		/* XXX */
87 #include <sys/_task.h>
88 
89 #define	IF_DUNIT_NONE	-1
90 
91 #include <altq/if_altq.h>
92 
93 TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
94 TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
95 TAILQ_HEAD(ifprefixhead, ifprefix);
96 TAILQ_HEAD(ifmultihead, ifmultiaddr);
97 TAILQ_HEAD(ifgrouphead, ifg_group);
98 
99 /*
100  * Structure defining a queue for a network interface.
101  */
102 struct	ifqueue {
103 	struct	mbuf *ifq_head;
104 	struct	mbuf *ifq_tail;
105 	int	ifq_len;
106 	int	ifq_maxlen;
107 	int	ifq_drops;
108 	struct	mtx ifq_mtx;
109 };
110 
111 /*
112  * Structure defining a network interface.
113  *
114  * (Would like to call this struct ``if'', but C isn't PL/1.)
115  */
116 
117 struct ifnet {
118 	void	*if_softc;		/* pointer to driver state */
119 	void	*if_l2com;		/* pointer to protocol bits */
120 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
121 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
122 	const char *if_dname;		/* driver name */
123 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
124 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
125 		/*
126 		 * if_addrhead is the list of all addresses associated to
127 		 * an interface.
128 		 * Some code in the kernel assumes that first element
129 		 * of the list has type AF_LINK, and contains sockaddr_dl
130 		 * addresses which store the link-level address and the name
131 		 * of the interface.
132 		 * However, access to the AF_LINK address through this
133 		 * field is deprecated. Use if_addr or ifaddr_byindex() instead.
134 		 */
135 	struct	knlist if_klist;	/* events attached to this if */
136 	int	if_pcount;		/* number of promiscuous listeners */
137 	struct	carp_if *if_carp;	/* carp interface structure */
138 	struct	bpf_if *if_bpf;		/* packet filter structure */
139 	u_short	if_index;		/* numeric abbreviation for this if  */
140 	short	if_timer;		/* time 'til if_watchdog called */
141 	struct  ifvlantrunk *if_vlantrunk; /* pointer to 802.1q data */
142 	int	if_flags;		/* up/down, broadcast, etc. */
143 	int	if_capabilities;	/* interface features & capabilities */
144 	int	if_capenable;		/* enabled features & capabilities */
145 	void	*if_linkmib;		/* link-type-specific MIB data */
146 	size_t	if_linkmiblen;		/* length of above data */
147 	struct	if_data if_data;
148 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
149 	int	if_amcount;		/* number of all-multicast requests */
150 /* procedure handles */
151 	int	(*if_output)		/* output routine (enqueue) */
152 		(struct ifnet *, struct mbuf *, struct sockaddr *,
153 		     struct route *);
154 	void	(*if_input)		/* input routine (from h/w driver) */
155 		(struct ifnet *, struct mbuf *);
156 	void	(*if_start)		/* initiate output routine */
157 		(struct ifnet *);
158 	int	(*if_ioctl)		/* ioctl routine */
159 		(struct ifnet *, u_long, caddr_t);
160 	void	(*if_watchdog)		/* timer routine */
161 		(struct ifnet *);
162 	void	(*if_init)		/* Init routine */
163 		(void *);
164 	int	(*if_resolvemulti)	/* validate/resolve multicast */
165 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
166 	void	(*if_qflush)		/* flush any queues */
167 		(struct ifnet *);
168 	int	(*if_transmit)		/* initiate output routine */
169 		(struct ifnet *, struct mbuf *);
170 	struct	ifaddr	*if_addr;	/* pointer to link-level address */
171 	void	*if_llsoftc;		/* link layer softc */
172 	int	if_drv_flags;		/* driver-managed status flags */
173 	struct  ifaltq if_snd;		/* output queue (includes altq) */
174 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
175 
176 	void	*if_bridge;		/* bridge glue */
177 
178 	struct	label *if_label;	/* interface MAC label */
179 
180 	/* these are only used by IPv6 */
181 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
182 	void	*if_afdata[AF_MAX];
183 	int	if_afdata_initialized;
184 	struct	rwlock if_afdata_lock;
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 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
383 	    int adjust);
384 #define	IF_HANDOFF(ifq, m, ifp)			\
385 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
386 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
387 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
388 
389 void	if_start(struct ifnet *);
390 
391 #define	IFQ_ENQUEUE(ifq, m, err)					\
392 do {									\
393 	IF_LOCK(ifq);							\
394 	if (ALTQ_IS_ENABLED(ifq))					\
395 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
396 	else {								\
397 		if (_IF_QFULL(ifq)) {					\
398 			m_freem(m);					\
399 			(err) = ENOBUFS;				\
400 		} else {						\
401 			_IF_ENQUEUE(ifq, m);				\
402 			(err) = 0;					\
403 		}							\
404 	}								\
405 	if (err)							\
406 		(ifq)->ifq_drops++;					\
407 	IF_UNLOCK(ifq);							\
408 } while (0)
409 
410 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
411 do {									\
412 	if (TBR_IS_ENABLED(ifq))					\
413 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
414 	else if (ALTQ_IS_ENABLED(ifq))					\
415 		ALTQ_DEQUEUE(ifq, m);					\
416 	else								\
417 		_IF_DEQUEUE(ifq, m);					\
418 } while (0)
419 
420 #define	IFQ_DEQUEUE(ifq, m)						\
421 do {									\
422 	IF_LOCK(ifq);							\
423 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
424 	IF_UNLOCK(ifq);							\
425 } while (0)
426 
427 #define	IFQ_POLL_NOLOCK(ifq, m)						\
428 do {									\
429 	if (TBR_IS_ENABLED(ifq))					\
430 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
431 	else if (ALTQ_IS_ENABLED(ifq))					\
432 		ALTQ_POLL(ifq, m);					\
433 	else								\
434 		_IF_POLL(ifq, m);					\
435 } while (0)
436 
437 #define	IFQ_POLL(ifq, m)						\
438 do {									\
439 	IF_LOCK(ifq);							\
440 	IFQ_POLL_NOLOCK(ifq, m);					\
441 	IF_UNLOCK(ifq);							\
442 } while (0)
443 
444 #define	IFQ_PURGE_NOLOCK(ifq)						\
445 do {									\
446 	if (ALTQ_IS_ENABLED(ifq)) {					\
447 		ALTQ_PURGE(ifq);					\
448 	} else								\
449 		_IF_DRAIN(ifq);						\
450 } while (0)
451 
452 #define	IFQ_PURGE(ifq)							\
453 do {									\
454 	IF_LOCK(ifq);							\
455 	IFQ_PURGE_NOLOCK(ifq);						\
456 	IF_UNLOCK(ifq);							\
457 } while (0)
458 
459 #define	IFQ_SET_READY(ifq)						\
460 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
461 
462 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
463 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
464 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
465 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
466 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
467 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
468 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
469 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
470 
471 /*
472  * The IFF_DRV_OACTIVE test should really occur in the device driver, not in
473  * the handoff logic, as that flag is locked by the device driver.
474  */
475 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
476 do {									\
477 	int len;							\
478 	short mflags;							\
479 									\
480 	len = (m)->m_pkthdr.len;					\
481 	mflags = (m)->m_flags;						\
482 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
483 	if ((err) == 0) {						\
484 		(ifp)->if_obytes += len + (adj);			\
485 		if (mflags & M_MCAST)					\
486 			(ifp)->if_omcasts++;				\
487 		if (((ifp)->if_drv_flags & IFF_DRV_OACTIVE) == 0)	\
488 			if_start(ifp);					\
489 	}								\
490 } while (0)
491 
492 #define	IFQ_HANDOFF(ifp, m, err)					\
493 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
494 
495 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
496 do {									\
497 	(m) = (ifq)->ifq_drv_head;					\
498 	if (m) {							\
499 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
500 			(ifq)->ifq_drv_tail = NULL;			\
501 		(m)->m_nextpkt = NULL;					\
502 		(ifq)->ifq_drv_len--;					\
503 	} else {							\
504 		IFQ_LOCK(ifq);						\
505 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
506 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
507 			struct mbuf *m0;				\
508 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
509 			if (m0 == NULL)					\
510 				break;					\
511 			m0->m_nextpkt = NULL;				\
512 			if ((ifq)->ifq_drv_tail == NULL)		\
513 				(ifq)->ifq_drv_head = m0;		\
514 			else						\
515 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
516 			(ifq)->ifq_drv_tail = m0;			\
517 			(ifq)->ifq_drv_len++;				\
518 		}							\
519 		IFQ_UNLOCK(ifq);					\
520 	}								\
521 } while (0)
522 
523 #define	IFQ_DRV_PREPEND(ifq, m)						\
524 do {									\
525 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
526 	if ((ifq)->ifq_drv_tail == NULL)				\
527 		(ifq)->ifq_drv_tail = (m);				\
528 	(ifq)->ifq_drv_head = (m);					\
529 	(ifq)->ifq_drv_len++;						\
530 } while (0)
531 
532 #define	IFQ_DRV_IS_EMPTY(ifq)						\
533 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
534 
535 #define	IFQ_DRV_PURGE(ifq)						\
536 do {									\
537 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
538 	while((m = n) != NULL) {					\
539 		n = m->m_nextpkt;					\
540 		m_freem(m);						\
541 	}								\
542 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
543 	(ifq)->ifq_drv_len = 0;						\
544 	IFQ_PURGE(ifq);							\
545 } while (0)
546 
547 #ifdef _KERNEL
548 static __inline void
549 drbr_stats_update(struct ifnet *ifp, int len, int mflags)
550 {
551 
552 	ifp->if_obytes += len;
553 	if (mflags & M_MCAST)
554 		ifp->if_omcasts++;
555 }
556 
557 static __inline int
558 drbr_enqueue(struct ifnet *ifp, struct buf_ring *br, struct mbuf *m)
559 {
560 	int error = 0;
561 	int len = m->m_pkthdr.len;
562 	int mflags = m->m_flags;
563 
564 #ifdef ALTQ
565 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
566 		IFQ_ENQUEUE(&ifp->if_snd, m, error);
567 		return (error);
568 	}
569 #endif
570 	if ((error = buf_ring_enqueue(br, m)) == ENOBUFS) {
571 		br->br_drops++;
572 		_IF_DROP(&ifp->if_snd);
573 		m_freem(m);
574 	} else
575 		drbr_stats_update(ifp, len, mflags);
576 
577 	return (error);
578 }
579 
580 static __inline void
581 drbr_free(struct buf_ring *br, struct malloc_type *type)
582 {
583 	struct mbuf *m;
584 
585 	while ((m = buf_ring_dequeue_sc(br)) != NULL)
586 		m_freem(m);
587 
588 	buf_ring_free(br, type);
589 }
590 
591 static __inline struct mbuf *
592 drbr_dequeue(struct ifnet *ifp, struct buf_ring *br)
593 {
594 #ifdef ALTQ
595 	struct mbuf *m;
596 
597 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
598 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
599 		return (m);
600 	}
601 #endif
602 	return (buf_ring_dequeue_sc(br));
603 }
604 
605 static __inline int
606 drbr_empty(struct ifnet *ifp, struct buf_ring *br)
607 {
608 #ifdef ALTQ
609 	if (ALTQ_IS_ENABLED(&ifp->if_snd))
610 		return (IFQ_DRV_IS_EMPTY(&ifp->if_snd));
611 #endif
612 	return (buf_ring_empty(br));
613 }
614 #endif
615 /*
616  * 72 was chosen below because it is the size of a TCP/IP
617  * header (40) + the minimum mss (32).
618  */
619 #define	IF_MINMTU	72
620 #define	IF_MAXMTU	65535
621 
622 #endif /* _KERNEL */
623 
624 /*
625  * The ifaddr structure contains information about one address
626  * of an interface.  They are maintained by the different address families,
627  * are allocated and attached when an address is set, and are linked
628  * together so all addresses for an interface can be located.
629  *
630  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
631  * chunk of malloc'ed memory, where we store the three addresses
632  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
633  */
634 struct ifaddr {
635 	struct	sockaddr *ifa_addr;	/* address of interface */
636 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
637 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
638 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
639 	struct	if_data if_data;	/* not all members are meaningful */
640 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
641 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
642 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
643 		(int, struct rtentry *, struct rt_addrinfo *);
644 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
645 	u_int	ifa_refcnt;		/* references to this structure */
646 	int	ifa_metric;		/* cost of going out this interface */
647 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
648 		(struct ifaddr *, struct sockaddr *);
649 	struct mtx ifa_mtx;
650 };
651 #define	IFA_ROUTE	RTF_UP		/* route installed */
652 
653 /* for compatibility with other BSDs */
654 #define	ifa_list	ifa_link
655 
656 #define	IFA_LOCK_INIT(ifa)	\
657     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
658 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
659 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
660 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
661 
662 /*
663  * The prefix structure contains information about one prefix
664  * of an interface.  They are maintained by the different address families,
665  * are allocated and attached when a prefix or an address is set,
666  * and are linked together so all prefixes for an interface can be located.
667  */
668 struct ifprefix {
669 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
670 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
671 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
672 	u_char	ifpr_plen;		/* prefix length in bits */
673 	u_char	ifpr_type;		/* protocol dependent prefix type */
674 };
675 
676 /*
677  * Multicast address structure.  This is analogous to the ifaddr
678  * structure except that it keeps track of multicast addresses.
679  */
680 struct ifmultiaddr {
681 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
682 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
683 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
684 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
685 	u_int	ifma_refcount;		/* reference count */
686 	void	*ifma_protospec;	/* protocol-specific state, if any */
687 	struct	ifmultiaddr *ifma_llifma; /* pointer to ifma for ifma_lladdr */
688 };
689 
690 #ifdef _KERNEL
691 #define	IFAFREE(ifa)					\
692 	do {						\
693 		IFA_LOCK(ifa);				\
694 		KASSERT((ifa)->ifa_refcnt > 0,		\
695 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
696 		if (--(ifa)->ifa_refcnt == 0) {		\
697 			IFA_DESTROY(ifa);		\
698 			free(ifa, M_IFADDR);		\
699 		} else 					\
700 			IFA_UNLOCK(ifa);		\
701 	} while (0)
702 
703 #define IFAREF(ifa)					\
704 	do {						\
705 		IFA_LOCK(ifa);				\
706 		++(ifa)->ifa_refcnt;			\
707 		IFA_UNLOCK(ifa);			\
708 	} while (0)
709 
710 extern	struct rwlock ifnet_lock;
711 #define	IFNET_LOCK_INIT() \
712    rw_init_flags(&ifnet_lock, "ifnet",  RW_RECURSE)
713 #define	IFNET_WLOCK()		rw_wlock(&ifnet_lock)
714 #define	IFNET_WUNLOCK()		rw_wunlock(&ifnet_lock)
715 #define	IFNET_WLOCK_ASSERT()	rw_assert(&ifnet_lock, RA_LOCKED)
716 #define	IFNET_RLOCK()		rw_rlock(&ifnet_lock)
717 #define	IFNET_RUNLOCK()		rw_runlock(&ifnet_lock)
718 
719 struct ifindex_entry {
720 	struct	ifnet *ife_ifnet;
721 	struct cdev *ife_dev;
722 };
723 
724 struct ifnet	*ifnet_byindex(u_short idx);
725 
726 /*
727  * Given the index, ifaddr_byindex() returns the one and only
728  * link-level ifaddr for the interface. You are not supposed to use
729  * it to traverse the list of addresses associated to the interface.
730  */
731 struct ifaddr	*ifaddr_byindex(u_short idx);
732 struct cdev	*ifdev_byindex(u_short idx);
733 
734 #ifdef VIMAGE_GLOBALS
735 extern	struct ifnethead ifnet;
736 extern	struct ifnet *loif;	/* first loopback interface */
737 extern	int if_index;
738 #endif
739 extern	int ifqmaxlen;
740 
741 int	if_addgroup(struct ifnet *, const char *);
742 int	if_delgroup(struct ifnet *, const char *);
743 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
744 int	if_allmulti(struct ifnet *, int);
745 struct	ifnet* if_alloc(u_char);
746 void	if_attach(struct ifnet *);
747 int	if_delmulti(struct ifnet *, struct sockaddr *);
748 void	if_delmulti_ifma(struct ifmultiaddr *);
749 void	if_detach(struct ifnet *);
750 void	if_purgeaddrs(struct ifnet *);
751 void	if_purgemaddrs(struct ifnet *);
752 void	if_down(struct ifnet *);
753 struct ifmultiaddr *
754 	if_findmulti(struct ifnet *, struct sockaddr *);
755 void	if_free(struct ifnet *);
756 void	if_free_type(struct ifnet *, u_char);
757 void	if_initname(struct ifnet *, const char *, int);
758 void	if_link_state_change(struct ifnet *, int);
759 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
760 void	if_qflush(struct ifnet *);
761 int	if_setlladdr(struct ifnet *, const u_char *, int);
762 void	if_up(struct ifnet *);
763 /*void	ifinit(void);*/ /* declared in systm.h for main() */
764 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
765 int	ifpromisc(struct ifnet *, int);
766 struct	ifnet *ifunit(const char *);
767 
768 void	ifq_attach(struct ifaltq *, struct ifnet *ifp);
769 void	ifq_detach(struct ifaltq *);
770 
771 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
772 struct	ifaddr *ifa_ifwithbroadaddr(struct sockaddr *);
773 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
774 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
775 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
776 struct	ifaddr *ifa_ifwithroute_fib(int, struct sockaddr *, struct sockaddr *, u_int);
777 
778 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
779 
780 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
781 
782 typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
783 typedef	void if_com_free_t(void *com, u_char type);
784 void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
785 void	if_deregister_com_alloc(u_char type);
786 
787 #define IF_LLADDR(ifp)							\
788     LLADDR((struct sockaddr_dl *)((ifp)->if_addr->ifa_addr))
789 
790 #ifdef DEVICE_POLLING
791 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS };
792 
793 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
794 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
795 int    ether_poll_deregister(struct ifnet *ifp);
796 #endif /* DEVICE_POLLING */
797 
798 #endif /* _KERNEL */
799 
800 #endif /* !_NET_IF_VAR_H_ */
801