xref: /freebsd/sys/net/if_var.h (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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 	struct vnet *if_vnet;		/* pointer to network stack instance */
121 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
122 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
123 	const char *if_dname;		/* driver name */
124 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
125 	u_int	if_refcount;		/* reference count */
126 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
127 		/*
128 		 * if_addrhead is the list of all addresses associated to
129 		 * an interface.
130 		 * Some code in the kernel assumes that first element
131 		 * of the list has type AF_LINK, and contains sockaddr_dl
132 		 * addresses which store the link-level address and the name
133 		 * of the interface.
134 		 * However, access to the AF_LINK address through this
135 		 * field is deprecated. Use if_addr or ifaddr_byindex() instead.
136 		 */
137 	struct	knlist if_klist;	/* events attached to this if */
138 	int	if_pcount;		/* number of promiscuous listeners */
139 	struct	carp_if *if_carp;	/* carp interface structure */
140 	struct	bpf_if *if_bpf;		/* packet filter structure */
141 	u_short	if_index;		/* numeric abbreviation for this if  */
142 	short	if_timer;		/* time 'til if_watchdog called */
143 	struct  ifvlantrunk *if_vlantrunk; /* pointer to 802.1q data */
144 	int	if_flags;		/* up/down, broadcast, etc. */
145 	int	if_capabilities;	/* interface features & capabilities */
146 	int	if_capenable;		/* enabled features & capabilities */
147 	void	*if_linkmib;		/* link-type-specific MIB data */
148 	size_t	if_linkmiblen;		/* length of above data */
149 	struct	if_data if_data;
150 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
151 	int	if_amcount;		/* number of all-multicast requests */
152 /* procedure handles */
153 	int	(*if_output)		/* output routine (enqueue) */
154 		(struct ifnet *, struct mbuf *, struct sockaddr *,
155 		     struct route *);
156 	void	(*if_input)		/* input routine (from h/w driver) */
157 		(struct ifnet *, struct mbuf *);
158 	void	(*if_start)		/* initiate output routine */
159 		(struct ifnet *);
160 	int	(*if_ioctl)		/* ioctl routine */
161 		(struct ifnet *, u_long, caddr_t);
162 	void	(*if_watchdog)		/* timer routine */
163 		(struct ifnet *);
164 	void	(*if_init)		/* Init routine */
165 		(void *);
166 	int	(*if_resolvemulti)	/* validate/resolve multicast */
167 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
168 	void	(*if_qflush)		/* flush any queues */
169 		(struct ifnet *);
170 	int	(*if_transmit)		/* initiate output routine */
171 		(struct ifnet *, struct mbuf *);
172 	struct	ifaddr	*if_addr;	/* pointer to link-level address */
173 	void	*if_llsoftc;		/* link layer softc */
174 	int	if_drv_flags;		/* driver-managed status flags */
175 	struct  ifaltq if_snd;		/* output queue (includes altq) */
176 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
177 
178 	void	*if_bridge;		/* bridge glue */
179 
180 	struct	label *if_label;	/* interface MAC label */
181 
182 	/* these are only used by IPv6 */
183 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
184 	void	*if_afdata[AF_MAX];
185 	int	if_afdata_initialized;
186 	struct	rwlock if_afdata_lock;
187 	struct	task if_linktask;	/* task for link change events */
188 	struct	mtx if_addr_mtx;	/* mutex to protect address lists */
189 
190 	LIST_ENTRY(ifnet) if_clones;	/* interfaces of a cloner */
191 	TAILQ_HEAD(, ifg_list) if_groups; /* linked list of groups per if */
192 					/* protected by if_addr_mtx */
193 	void	*if_pf_kif;
194 	void	*if_lagg;		/* lagg glue */
195 	u_char	 if_alloctype;		/* if_type at time of allocation */
196 
197 	/*
198 	 * Spare fields are added so that we can modify sensitive data
199 	 * structures without changing the kernel binary interface, and must
200 	 * be used with care where binary compatibility is required.
201 	 */
202 	char	 if_cspare[3];
203 	void	*if_pspare[8];
204 	int	if_ispare[4];
205 };
206 
207 typedef void if_init_f_t(void *);
208 
209 /*
210  * XXX These aliases are terribly dangerous because they could apply
211  * to anything.
212  */
213 #define	if_mtu		if_data.ifi_mtu
214 #define	if_type		if_data.ifi_type
215 #define if_physical	if_data.ifi_physical
216 #define	if_addrlen	if_data.ifi_addrlen
217 #define	if_hdrlen	if_data.ifi_hdrlen
218 #define	if_metric	if_data.ifi_metric
219 #define	if_link_state	if_data.ifi_link_state
220 #define	if_baudrate	if_data.ifi_baudrate
221 #define	if_hwassist	if_data.ifi_hwassist
222 #define	if_ipackets	if_data.ifi_ipackets
223 #define	if_ierrors	if_data.ifi_ierrors
224 #define	if_opackets	if_data.ifi_opackets
225 #define	if_oerrors	if_data.ifi_oerrors
226 #define	if_collisions	if_data.ifi_collisions
227 #define	if_ibytes	if_data.ifi_ibytes
228 #define	if_obytes	if_data.ifi_obytes
229 #define	if_imcasts	if_data.ifi_imcasts
230 #define	if_omcasts	if_data.ifi_omcasts
231 #define	if_iqdrops	if_data.ifi_iqdrops
232 #define	if_noproto	if_data.ifi_noproto
233 #define	if_lastchange	if_data.ifi_lastchange
234 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
235 
236 /* for compatibility with other BSDs */
237 #define	if_addrlist	if_addrhead
238 #define	if_list		if_link
239 #define	if_name(ifp)	((ifp)->if_xname)
240 
241 /*
242  * Locks for address lists on the network interface.
243  */
244 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
245 				    "if_addr_mtx", NULL, MTX_DEF)
246 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
247 #define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
248 #define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
249 #define	IF_ADDR_LOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
250 
251 /*
252  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
253  * are queues of messages stored on ifqueue structures
254  * (defined above).  Entries are added to and deleted from these structures
255  * by these macros, which should be called with ipl raised to splimp().
256  */
257 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
258 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
259 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
260 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
261 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
262 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
263 
264 #define	_IF_ENQUEUE(ifq, m) do { 				\
265 	(m)->m_nextpkt = NULL;					\
266 	if ((ifq)->ifq_tail == NULL) 				\
267 		(ifq)->ifq_head = m; 				\
268 	else 							\
269 		(ifq)->ifq_tail->m_nextpkt = m; 		\
270 	(ifq)->ifq_tail = m; 					\
271 	(ifq)->ifq_len++; 					\
272 } while (0)
273 
274 #define IF_ENQUEUE(ifq, m) do {					\
275 	IF_LOCK(ifq); 						\
276 	_IF_ENQUEUE(ifq, m); 					\
277 	IF_UNLOCK(ifq); 					\
278 } while (0)
279 
280 #define	_IF_PREPEND(ifq, m) do {				\
281 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
282 	if ((ifq)->ifq_tail == NULL) 				\
283 		(ifq)->ifq_tail = (m); 				\
284 	(ifq)->ifq_head = (m); 					\
285 	(ifq)->ifq_len++; 					\
286 } while (0)
287 
288 #define IF_PREPEND(ifq, m) do {		 			\
289 	IF_LOCK(ifq); 						\
290 	_IF_PREPEND(ifq, m); 					\
291 	IF_UNLOCK(ifq); 					\
292 } while (0)
293 
294 #define	_IF_DEQUEUE(ifq, m) do { 				\
295 	(m) = (ifq)->ifq_head; 					\
296 	if (m) { 						\
297 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
298 			(ifq)->ifq_tail = NULL; 		\
299 		(m)->m_nextpkt = NULL; 				\
300 		(ifq)->ifq_len--; 				\
301 	} 							\
302 } while (0)
303 
304 #define IF_DEQUEUE(ifq, m) do { 				\
305 	IF_LOCK(ifq); 						\
306 	_IF_DEQUEUE(ifq, m); 					\
307 	IF_UNLOCK(ifq); 					\
308 } while (0)
309 
310 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
311 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
312 
313 #define _IF_DRAIN(ifq) do { 					\
314 	struct mbuf *m; 					\
315 	for (;;) { 						\
316 		_IF_DEQUEUE(ifq, m); 				\
317 		if (m == NULL) 					\
318 			break; 					\
319 		m_freem(m); 					\
320 	} 							\
321 } while (0)
322 
323 #define IF_DRAIN(ifq) do {					\
324 	IF_LOCK(ifq);						\
325 	_IF_DRAIN(ifq);						\
326 	IF_UNLOCK(ifq);						\
327 } while(0)
328 
329 #ifdef _KERNEL
330 /* interface address change event */
331 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
332 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
333 /* new interface arrival event */
334 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
335 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
336 /* interface departure event */
337 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
338 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
339 
340 /*
341  * interface groups
342  */
343 struct ifg_group {
344 	char				 ifg_group[IFNAMSIZ];
345 	u_int				 ifg_refcnt;
346 	void				*ifg_pf_kif;
347 	TAILQ_HEAD(, ifg_member)	 ifg_members;
348 	TAILQ_ENTRY(ifg_group)		 ifg_next;
349 };
350 
351 struct ifg_member {
352 	TAILQ_ENTRY(ifg_member)	 ifgm_next;
353 	struct ifnet		*ifgm_ifp;
354 };
355 
356 struct ifg_list {
357 	struct ifg_group	*ifgl_group;
358 	TAILQ_ENTRY(ifg_list)	 ifgl_next;
359 };
360 
361 /* group attach event */
362 typedef void (*group_attach_event_handler_t)(void *, struct ifg_group *);
363 EVENTHANDLER_DECLARE(group_attach_event, group_attach_event_handler_t);
364 /* group detach event */
365 typedef void (*group_detach_event_handler_t)(void *, struct ifg_group *);
366 EVENTHANDLER_DECLARE(group_detach_event, group_detach_event_handler_t);
367 /* group change event */
368 typedef void (*group_change_event_handler_t)(void *, const char *);
369 EVENTHANDLER_DECLARE(group_change_event, group_change_event_handler_t);
370 
371 #define	IF_AFDATA_LOCK_INIT(ifp)	\
372 	rw_init(&(ifp)->if_afdata_lock, "if_afdata")
373 
374 #define	IF_AFDATA_WLOCK(ifp)	rw_wlock(&(ifp)->if_afdata_lock)
375 #define	IF_AFDATA_RLOCK(ifp)	rw_rlock(&(ifp)->if_afdata_lock)
376 #define	IF_AFDATA_WUNLOCK(ifp)	rw_wunlock(&(ifp)->if_afdata_lock)
377 #define	IF_AFDATA_RUNLOCK(ifp)	rw_runlock(&(ifp)->if_afdata_lock)
378 #define	IF_AFDATA_LOCK(ifp)	IF_AFDATA_WLOCK(ifp)
379 #define	IF_AFDATA_UNLOCK(ifp)	IF_AFDATA_WUNLOCK(ifp)
380 #define	IF_AFDATA_TRYLOCK(ifp)	rw_try_wlock(&(ifp)->if_afdata_lock)
381 #define	IF_AFDATA_DESTROY(ifp)	rw_destroy(&(ifp)->if_afdata_lock)
382 
383 #define	IF_AFDATA_LOCK_ASSERT(ifp)	rw_assert(&(ifp)->if_afdata_lock, RA_LOCKED)
384 #define	IF_AFDATA_UNLOCK_ASSERT(ifp)	rw_assert(&(ifp)->if_afdata_lock, RA_UNLOCKED)
385 
386 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
387 	    int adjust);
388 #define	IF_HANDOFF(ifq, m, ifp)			\
389 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
390 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
391 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
392 
393 void	if_start(struct ifnet *);
394 
395 #define	IFQ_ENQUEUE(ifq, m, err)					\
396 do {									\
397 	IF_LOCK(ifq);							\
398 	if (ALTQ_IS_ENABLED(ifq))					\
399 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
400 	else {								\
401 		if (_IF_QFULL(ifq)) {					\
402 			m_freem(m);					\
403 			(err) = ENOBUFS;				\
404 		} else {						\
405 			_IF_ENQUEUE(ifq, m);				\
406 			(err) = 0;					\
407 		}							\
408 	}								\
409 	if (err)							\
410 		(ifq)->ifq_drops++;					\
411 	IF_UNLOCK(ifq);							\
412 } while (0)
413 
414 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
415 do {									\
416 	if (TBR_IS_ENABLED(ifq))					\
417 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
418 	else if (ALTQ_IS_ENABLED(ifq))					\
419 		ALTQ_DEQUEUE(ifq, m);					\
420 	else								\
421 		_IF_DEQUEUE(ifq, m);					\
422 } while (0)
423 
424 #define	IFQ_DEQUEUE(ifq, m)						\
425 do {									\
426 	IF_LOCK(ifq);							\
427 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
428 	IF_UNLOCK(ifq);							\
429 } while (0)
430 
431 #define	IFQ_POLL_NOLOCK(ifq, m)						\
432 do {									\
433 	if (TBR_IS_ENABLED(ifq))					\
434 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
435 	else if (ALTQ_IS_ENABLED(ifq))					\
436 		ALTQ_POLL(ifq, m);					\
437 	else								\
438 		_IF_POLL(ifq, m);					\
439 } while (0)
440 
441 #define	IFQ_POLL(ifq, m)						\
442 do {									\
443 	IF_LOCK(ifq);							\
444 	IFQ_POLL_NOLOCK(ifq, m);					\
445 	IF_UNLOCK(ifq);							\
446 } while (0)
447 
448 #define	IFQ_PURGE_NOLOCK(ifq)						\
449 do {									\
450 	if (ALTQ_IS_ENABLED(ifq)) {					\
451 		ALTQ_PURGE(ifq);					\
452 	} else								\
453 		_IF_DRAIN(ifq);						\
454 } while (0)
455 
456 #define	IFQ_PURGE(ifq)							\
457 do {									\
458 	IF_LOCK(ifq);							\
459 	IFQ_PURGE_NOLOCK(ifq);						\
460 	IF_UNLOCK(ifq);							\
461 } while (0)
462 
463 #define	IFQ_SET_READY(ifq)						\
464 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
465 
466 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
467 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
468 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
469 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
470 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
471 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
472 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
473 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
474 
475 /*
476  * The IFF_DRV_OACTIVE test should really occur in the device driver, not in
477  * the handoff logic, as that flag is locked by the device driver.
478  */
479 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
480 do {									\
481 	int len;							\
482 	short mflags;							\
483 									\
484 	len = (m)->m_pkthdr.len;					\
485 	mflags = (m)->m_flags;						\
486 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
487 	if ((err) == 0) {						\
488 		(ifp)->if_obytes += len + (adj);			\
489 		if (mflags & M_MCAST)					\
490 			(ifp)->if_omcasts++;				\
491 		if (((ifp)->if_drv_flags & IFF_DRV_OACTIVE) == 0)	\
492 			if_start(ifp);					\
493 	}								\
494 } while (0)
495 
496 #define	IFQ_HANDOFF(ifp, m, err)					\
497 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
498 
499 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
500 do {									\
501 	(m) = (ifq)->ifq_drv_head;					\
502 	if (m) {							\
503 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
504 			(ifq)->ifq_drv_tail = NULL;			\
505 		(m)->m_nextpkt = NULL;					\
506 		(ifq)->ifq_drv_len--;					\
507 	} else {							\
508 		IFQ_LOCK(ifq);						\
509 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
510 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
511 			struct mbuf *m0;				\
512 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
513 			if (m0 == NULL)					\
514 				break;					\
515 			m0->m_nextpkt = NULL;				\
516 			if ((ifq)->ifq_drv_tail == NULL)		\
517 				(ifq)->ifq_drv_head = m0;		\
518 			else						\
519 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
520 			(ifq)->ifq_drv_tail = m0;			\
521 			(ifq)->ifq_drv_len++;				\
522 		}							\
523 		IFQ_UNLOCK(ifq);					\
524 	}								\
525 } while (0)
526 
527 #define	IFQ_DRV_PREPEND(ifq, m)						\
528 do {									\
529 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
530 	if ((ifq)->ifq_drv_tail == NULL)				\
531 		(ifq)->ifq_drv_tail = (m);				\
532 	(ifq)->ifq_drv_head = (m);					\
533 	(ifq)->ifq_drv_len++;						\
534 } while (0)
535 
536 #define	IFQ_DRV_IS_EMPTY(ifq)						\
537 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
538 
539 #define	IFQ_DRV_PURGE(ifq)						\
540 do {									\
541 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
542 	while((m = n) != NULL) {					\
543 		n = m->m_nextpkt;					\
544 		m_freem(m);						\
545 	}								\
546 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
547 	(ifq)->ifq_drv_len = 0;						\
548 	IFQ_PURGE(ifq);							\
549 } while (0)
550 
551 #ifdef _KERNEL
552 static __inline void
553 drbr_stats_update(struct ifnet *ifp, int len, int mflags)
554 {
555 
556 	ifp->if_obytes += len;
557 	if (mflags & M_MCAST)
558 		ifp->if_omcasts++;
559 }
560 
561 static __inline int
562 drbr_enqueue(struct ifnet *ifp, struct buf_ring *br, struct mbuf *m)
563 {
564 	int error = 0;
565 	int len = m->m_pkthdr.len;
566 	int mflags = m->m_flags;
567 
568 #ifdef ALTQ
569 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
570 		IFQ_ENQUEUE(&ifp->if_snd, m, error);
571 		return (error);
572 	}
573 #endif
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 
595 static __inline struct mbuf *
596 drbr_dequeue(struct ifnet *ifp, struct buf_ring *br)
597 {
598 #ifdef ALTQ
599 	struct mbuf *m;
600 
601 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
602 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
603 		return (m);
604 	}
605 #endif
606 	return (buf_ring_dequeue_sc(br));
607 }
608 
609 static __inline int
610 drbr_empty(struct ifnet *ifp, struct buf_ring *br)
611 {
612 #ifdef ALTQ
613 	if (ALTQ_IS_ENABLED(&ifp->if_snd))
614 		return (IFQ_DRV_IS_EMPTY(&ifp->if_snd));
615 #endif
616 	return (buf_ring_empty(br));
617 }
618 #endif
619 /*
620  * 72 was chosen below because it is the size of a TCP/IP
621  * header (40) + the minimum mss (32).
622  */
623 #define	IF_MINMTU	72
624 #define	IF_MAXMTU	65535
625 
626 #endif /* _KERNEL */
627 
628 /*
629  * The ifaddr structure contains information about one address
630  * of an interface.  They are maintained by the different address families,
631  * are allocated and attached when an address is set, and are linked
632  * together so all addresses for an interface can be located.
633  *
634  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
635  * chunk of malloc'ed memory, where we store the three addresses
636  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
637  */
638 struct ifaddr {
639 	struct	sockaddr *ifa_addr;	/* address of interface */
640 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
641 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
642 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
643 	struct	if_data if_data;	/* not all members are meaningful */
644 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
645 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
646 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
647 		(int, struct rtentry *, struct rt_addrinfo *);
648 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
649 	u_int	ifa_refcnt;		/* references to this structure */
650 	int	ifa_metric;		/* cost of going out this interface */
651 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
652 		(struct ifaddr *, struct sockaddr *);
653 	struct mtx ifa_mtx;
654 };
655 #define	IFA_ROUTE	RTF_UP		/* route installed */
656 
657 /* for compatibility with other BSDs */
658 #define	ifa_list	ifa_link
659 
660 #define	IFA_LOCK_INIT(ifa)	\
661     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
662 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
663 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
664 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
665 
666 /*
667  * The prefix structure contains information about one prefix
668  * of an interface.  They are maintained by the different address families,
669  * are allocated and attached when a prefix or an address is set,
670  * and are linked together so all prefixes for an interface can be located.
671  */
672 struct ifprefix {
673 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
674 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
675 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
676 	u_char	ifpr_plen;		/* prefix length in bits */
677 	u_char	ifpr_type;		/* protocol dependent prefix type */
678 };
679 
680 /*
681  * Multicast address structure.  This is analogous to the ifaddr
682  * structure except that it keeps track of multicast addresses.
683  */
684 struct ifmultiaddr {
685 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
686 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
687 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
688 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
689 	u_int	ifma_refcount;		/* reference count */
690 	void	*ifma_protospec;	/* protocol-specific state, if any */
691 	struct	ifmultiaddr *ifma_llifma; /* pointer to ifma for ifma_lladdr */
692 };
693 
694 #ifdef _KERNEL
695 #define	IFAFREE(ifa)					\
696 	do {						\
697 		IFA_LOCK(ifa);				\
698 		KASSERT((ifa)->ifa_refcnt > 0,		\
699 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
700 		if (--(ifa)->ifa_refcnt == 0) {		\
701 			IFA_DESTROY(ifa);		\
702 			free(ifa, M_IFADDR);		\
703 		} else 					\
704 			IFA_UNLOCK(ifa);		\
705 	} while (0)
706 
707 #define IFAREF(ifa)					\
708 	do {						\
709 		IFA_LOCK(ifa);				\
710 		++(ifa)->ifa_refcnt;			\
711 		IFA_UNLOCK(ifa);			\
712 	} while (0)
713 
714 extern	struct rwlock ifnet_lock;
715 #define	IFNET_LOCK_INIT() \
716    rw_init_flags(&ifnet_lock, "ifnet",  RW_RECURSE)
717 #define	IFNET_WLOCK()		rw_wlock(&ifnet_lock)
718 #define	IFNET_WUNLOCK()		rw_wunlock(&ifnet_lock)
719 #define	IFNET_WLOCK_ASSERT()	rw_assert(&ifnet_lock, RA_LOCKED)
720 #define	IFNET_RLOCK()		rw_rlock(&ifnet_lock)
721 #define	IFNET_RUNLOCK()		rw_runlock(&ifnet_lock)
722 
723 struct ifindex_entry {
724 	struct	ifnet *ife_ifnet;
725 	struct cdev *ife_dev;
726 };
727 
728 /*
729  * Look up an ifnet given its index; the _ref variant also acquires a
730  * reference that must be freed using if_rele().  It is almost always a bug
731  * to call ifnet_byindex() instead if ifnet_byindex_ref().
732  */
733 struct ifnet	*ifnet_byindex(u_short idx);
734 struct ifnet	*ifnet_byindex_locked(u_short idx);
735 struct ifnet	*ifnet_byindex_ref(u_short idx);
736 
737 /*
738  * Given the index, ifaddr_byindex() returns the one and only
739  * link-level ifaddr for the interface. You are not supposed to use
740  * it to traverse the list of addresses associated to the interface.
741  */
742 struct ifaddr	*ifaddr_byindex(u_short idx);
743 struct cdev	*ifdev_byindex(u_short idx);
744 
745 #ifdef VIMAGE_GLOBALS
746 extern	struct ifnethead ifnet;
747 extern	struct ifnet *loif;	/* first loopback interface */
748 extern	int if_index;
749 #endif
750 extern	int ifqmaxlen;
751 
752 int	if_addgroup(struct ifnet *, const char *);
753 int	if_delgroup(struct ifnet *, const char *);
754 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
755 int	if_allmulti(struct ifnet *, int);
756 struct	ifnet* if_alloc(u_char);
757 void	if_attach(struct ifnet *);
758 void	if_dead(struct ifnet *);
759 void	if_grow(void);
760 int	if_delmulti(struct ifnet *, struct sockaddr *);
761 void	if_delmulti_ifma(struct ifmultiaddr *);
762 void	if_detach(struct ifnet *);
763 void	if_vmove(struct ifnet *, struct vnet *);
764 void	if_purgeaddrs(struct ifnet *);
765 void	if_purgemaddrs(struct ifnet *);
766 void	if_down(struct ifnet *);
767 struct ifmultiaddr *
768 	if_findmulti(struct ifnet *, struct sockaddr *);
769 void	if_free(struct ifnet *);
770 void	if_free_type(struct ifnet *, u_char);
771 void	if_initname(struct ifnet *, const char *, int);
772 void	if_link_state_change(struct ifnet *, int);
773 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
774 void	if_qflush(struct ifnet *);
775 void	if_ref(struct ifnet *);
776 void	if_rele(struct ifnet *);
777 int	if_setlladdr(struct ifnet *, const u_char *, int);
778 void	if_up(struct ifnet *);
779 /*void	ifinit(void);*/ /* declared in systm.h for main() */
780 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
781 int	ifpromisc(struct ifnet *, int);
782 struct	ifnet *ifunit(const char *);
783 struct	ifnet *ifunit_ref(const char *);
784 
785 void	ifq_attach(struct ifaltq *, struct ifnet *ifp);
786 void	ifq_detach(struct ifaltq *);
787 
788 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
789 struct	ifaddr *ifa_ifwithbroadaddr(struct sockaddr *);
790 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
791 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
792 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
793 struct	ifaddr *ifa_ifwithroute_fib(int, struct sockaddr *, struct sockaddr *, u_int);
794 
795 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
796 
797 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
798 
799 typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
800 typedef	void if_com_free_t(void *com, u_char type);
801 void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
802 void	if_deregister_com_alloc(u_char type);
803 
804 #define IF_LLADDR(ifp)							\
805     LLADDR((struct sockaddr_dl *)((ifp)->if_addr->ifa_addr))
806 
807 #ifdef DEVICE_POLLING
808 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS };
809 
810 typedef	int poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
811 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
812 int    ether_poll_deregister(struct ifnet *ifp);
813 #endif /* DEVICE_POLLING */
814 
815 #endif /* _KERNEL */
816 
817 #endif /* !_NET_IF_VAR_H_ */
818