xref: /freebsd/sys/net/if_var.h (revision 3642298923e528d795e3a30ec165d2b469e28b40)
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 #endif
73 
74 #include <sys/queue.h>		/* get TAILQ macros */
75 
76 #ifdef _KERNEL
77 #include <sys/mbuf.h>
78 #include <sys/eventhandler.h>
79 #endif /* _KERNEL */
80 #include <sys/lock.h>		/* XXX */
81 #include <sys/mutex.h>		/* XXX */
82 #include <sys/event.h>		/* XXX */
83 #include <sys/_task.h>
84 
85 #define	IF_DUNIT_NONE	-1
86 
87 #include <altq/if_altq.h>
88 
89 TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
90 TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
91 TAILQ_HEAD(ifprefixhead, ifprefix);
92 TAILQ_HEAD(ifmultihead, ifmultiaddr);
93 
94 /*
95  * Structure defining a queue for a network interface.
96  */
97 struct	ifqueue {
98 	struct	mbuf *ifq_head;
99 	struct	mbuf *ifq_tail;
100 	int	ifq_len;
101 	int	ifq_maxlen;
102 	int	ifq_drops;
103 	struct	mtx ifq_mtx;
104 };
105 
106 /*
107  * Structure defining a network interface.
108  *
109  * (Would like to call this struct ``if'', but C isn't PL/1.)
110  */
111 
112 struct ifnet {
113 	void	*if_softc;		/* pointer to driver state */
114 	void	*if_l2com;		/* pointer to protocol bits */
115 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
116 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
117 	const char *if_dname;		/* driver name */
118 	int	if_dunit;		/* unit or IF_DUNIT_NONE */
119 	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
120 		/*
121 		 * if_addrhead is the list of all addresses associated to
122 		 * an interface.
123 		 * Some code in the kernel assumes that first element
124 		 * of the list has type AF_LINK, and contains sockaddr_dl
125 		 * addresses which store the link-level address and the name
126 		 * of the interface.
127 		 * However, access to the AF_LINK address through this
128 		 * field is deprecated. Use ifaddr_byindex() instead.
129 		 */
130 	struct	knlist if_klist;	/* events attached to this if */
131 	int	if_pcount;		/* number of promiscuous listeners */
132 	struct	carp_if *if_carp;	/* carp interface structure */
133 	struct	bpf_if *if_bpf;		/* packet filter structure */
134 	u_short	if_index;		/* numeric abbreviation for this if  */
135 	short	if_timer;		/* time 'til if_watchdog called */
136 	u_short	if_nvlans;		/* number of active vlans */
137 	int	if_flags;		/* up/down, broadcast, etc. */
138 	int	if_capabilities;	/* interface capabilities */
139 	int	if_capenable;		/* enabled features */
140 	void	*if_linkmib;		/* link-type-specific MIB data */
141 	size_t	if_linkmiblen;		/* length of above data */
142 	struct	if_data if_data;
143 	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
144 	int	if_amcount;		/* number of all-multicast requests */
145 /* procedure handles */
146 	int	(*if_output)		/* output routine (enqueue) */
147 		(struct ifnet *, struct mbuf *, struct sockaddr *,
148 		     struct rtentry *);
149 	void	(*if_input)		/* input routine (from h/w driver) */
150 		(struct ifnet *, struct mbuf *);
151 	void	(*if_start)		/* initiate output routine */
152 		(struct ifnet *);
153 	int	(*if_ioctl)		/* ioctl routine */
154 		(struct ifnet *, u_long, caddr_t);
155 	void	(*if_watchdog)		/* timer routine */
156 		(struct ifnet *);
157 	void	(*if_init)		/* Init routine */
158 		(void *);
159 	int	(*if_resolvemulti)	/* validate/resolve multicast */
160 		(struct ifnet *, struct sockaddr **, struct sockaddr *);
161 	void	*if_spare1;		/* spare pointer 1 */
162 	void	*if_spare2;		/* spare pointer 2 */
163 	void	*if_spare3;		/* spare pointer 3 */
164 	int	if_drv_flags;		/* driver-managed status flags */
165 	u_int	if_spare_flags2;	/* spare flags 2 */
166 	struct  ifaltq if_snd;		/* output queue (includes altq) */
167 	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
168 
169 	void	*if_bridge;		/* bridge glue */
170 
171 	struct	lltable *lltables;	/* list of L3-L2 resolution tables */
172 
173 	struct	label *if_label;	/* interface MAC label */
174 
175 	/* these are only used by IPv6 */
176 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
177 	void	*if_afdata[AF_MAX];
178 	int	if_afdata_initialized;
179 	struct	mtx if_afdata_mtx;
180 	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
181 	struct	task if_linktask;	/* task for link change events */
182 	struct	mtx if_addr_mtx;	/* mutex to protect address lists */
183 };
184 
185 typedef void if_init_f_t(void *);
186 
187 /*
188  * XXX These aliases are terribly dangerous because they could apply
189  * to anything.
190  */
191 #define	if_mtu		if_data.ifi_mtu
192 #define	if_type		if_data.ifi_type
193 #define if_physical	if_data.ifi_physical
194 #define	if_addrlen	if_data.ifi_addrlen
195 #define	if_hdrlen	if_data.ifi_hdrlen
196 #define	if_metric	if_data.ifi_metric
197 #define	if_link_state	if_data.ifi_link_state
198 #define	if_baudrate	if_data.ifi_baudrate
199 #define	if_hwassist	if_data.ifi_hwassist
200 #define	if_ipackets	if_data.ifi_ipackets
201 #define	if_ierrors	if_data.ifi_ierrors
202 #define	if_opackets	if_data.ifi_opackets
203 #define	if_oerrors	if_data.ifi_oerrors
204 #define	if_collisions	if_data.ifi_collisions
205 #define	if_ibytes	if_data.ifi_ibytes
206 #define	if_obytes	if_data.ifi_obytes
207 #define	if_imcasts	if_data.ifi_imcasts
208 #define	if_omcasts	if_data.ifi_omcasts
209 #define	if_iqdrops	if_data.ifi_iqdrops
210 #define	if_noproto	if_data.ifi_noproto
211 #define	if_lastchange	if_data.ifi_lastchange
212 #define if_recvquota	if_data.ifi_recvquota
213 #define	if_xmitquota	if_data.ifi_xmitquota
214 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
215 
216 /* for compatibility with other BSDs */
217 #define	if_addrlist	if_addrhead
218 #define	if_list		if_link
219 
220 /*
221  * Locks for address lists on the network interface.
222  */
223 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
224 				    "if_addr_mtx", NULL, MTX_DEF)
225 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
226 #define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
227 #define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
228 #define	IF_ADDR_LOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
229 
230 /*
231  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
232  * are queues of messages stored on ifqueue structures
233  * (defined above).  Entries are added to and deleted from these structures
234  * by these macros, which should be called with ipl raised to splimp().
235  */
236 #define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
237 #define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
238 #define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
239 #define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
240 #define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
241 #define	_IF_QLEN(ifq)		((ifq)->ifq_len)
242 
243 #define	_IF_ENQUEUE(ifq, m) do { 				\
244 	(m)->m_nextpkt = NULL;					\
245 	if ((ifq)->ifq_tail == NULL) 				\
246 		(ifq)->ifq_head = m; 				\
247 	else 							\
248 		(ifq)->ifq_tail->m_nextpkt = m; 		\
249 	(ifq)->ifq_tail = m; 					\
250 	(ifq)->ifq_len++; 					\
251 } while (0)
252 
253 #define IF_ENQUEUE(ifq, m) do {					\
254 	IF_LOCK(ifq); 						\
255 	_IF_ENQUEUE(ifq, m); 					\
256 	IF_UNLOCK(ifq); 					\
257 } while (0)
258 
259 #define	_IF_PREPEND(ifq, m) do {				\
260 	(m)->m_nextpkt = (ifq)->ifq_head; 			\
261 	if ((ifq)->ifq_tail == NULL) 				\
262 		(ifq)->ifq_tail = (m); 				\
263 	(ifq)->ifq_head = (m); 					\
264 	(ifq)->ifq_len++; 					\
265 } while (0)
266 
267 #define IF_PREPEND(ifq, m) do {		 			\
268 	IF_LOCK(ifq); 						\
269 	_IF_PREPEND(ifq, m); 					\
270 	IF_UNLOCK(ifq); 					\
271 } while (0)
272 
273 #define	_IF_DEQUEUE(ifq, m) do { 				\
274 	(m) = (ifq)->ifq_head; 					\
275 	if (m) { 						\
276 		if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL)	\
277 			(ifq)->ifq_tail = NULL; 		\
278 		(m)->m_nextpkt = NULL; 				\
279 		(ifq)->ifq_len--; 				\
280 	} 							\
281 } while (0)
282 
283 #define IF_DEQUEUE(ifq, m) do { 				\
284 	IF_LOCK(ifq); 						\
285 	_IF_DEQUEUE(ifq, m); 					\
286 	IF_UNLOCK(ifq); 					\
287 } while (0)
288 
289 #define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
290 #define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
291 
292 #define _IF_DRAIN(ifq) do { 					\
293 	struct mbuf *m; 					\
294 	for (;;) { 						\
295 		_IF_DEQUEUE(ifq, m); 				\
296 		if (m == NULL) 					\
297 			break; 					\
298 		m_freem(m); 					\
299 	} 							\
300 } while (0)
301 
302 #define IF_DRAIN(ifq) do {					\
303 	IF_LOCK(ifq);						\
304 	_IF_DRAIN(ifq);						\
305 	IF_UNLOCK(ifq);						\
306 } while(0)
307 
308 #ifdef _KERNEL
309 /* interface address change event */
310 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
311 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
312 /* new interface arrival event */
313 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
314 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
315 /* interface departure event */
316 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
317 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
318 
319 #define	IF_AFDATA_LOCK_INIT(ifp)	\
320     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
321 #define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
322 #define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
323 #define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
324 #define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
325 
326 #define	IFF_LOCKGIANT(ifp) do {						\
327 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
328 		mtx_lock(&Giant);					\
329 } while (0)
330 
331 #define	IFF_UNLOCKGIANT(ifp) do {					\
332 	if ((ifp)->if_flags & IFF_NEEDSGIANT)				\
333 		mtx_unlock(&Giant);					\
334 } while (0)
335 
336 int	if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
337 	    int adjust);
338 #define	IF_HANDOFF(ifq, m, ifp)			\
339 	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
340 #define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
341 	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
342 
343 void	if_start(struct ifnet *);
344 
345 #define	IFQ_ENQUEUE(ifq, m, err)					\
346 do {									\
347 	IF_LOCK(ifq);							\
348 	if (ALTQ_IS_ENABLED(ifq))					\
349 		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
350 	else {								\
351 		if (_IF_QFULL(ifq)) {					\
352 			m_freem(m);					\
353 			(err) = ENOBUFS;				\
354 		} else {						\
355 			_IF_ENQUEUE(ifq, m);				\
356 			(err) = 0;					\
357 		}							\
358 	}								\
359 	if (err)							\
360 		(ifq)->ifq_drops++;					\
361 	IF_UNLOCK(ifq);							\
362 } while (0)
363 
364 #define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
365 do {									\
366 	if (TBR_IS_ENABLED(ifq))					\
367 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
368 	else if (ALTQ_IS_ENABLED(ifq))					\
369 		ALTQ_DEQUEUE(ifq, m);					\
370 	else								\
371 		_IF_DEQUEUE(ifq, m);					\
372 } while (0)
373 
374 #define	IFQ_DEQUEUE(ifq, m)						\
375 do {									\
376 	IF_LOCK(ifq);							\
377 	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
378 	IF_UNLOCK(ifq);							\
379 } while (0)
380 
381 #define	IFQ_POLL_NOLOCK(ifq, m)						\
382 do {									\
383 	if (TBR_IS_ENABLED(ifq))					\
384 		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
385 	else if (ALTQ_IS_ENABLED(ifq))					\
386 		ALTQ_POLL(ifq, m);					\
387 	else								\
388 		_IF_POLL(ifq, m);					\
389 } while (0)
390 
391 #define	IFQ_POLL(ifq, m)						\
392 do {									\
393 	IF_LOCK(ifq);							\
394 	IFQ_POLL_NOLOCK(ifq, m);					\
395 	IF_UNLOCK(ifq);							\
396 } while (0)
397 
398 #define	IFQ_PURGE_NOLOCK(ifq)						\
399 do {									\
400 	if (ALTQ_IS_ENABLED(ifq)) {					\
401 		ALTQ_PURGE(ifq);					\
402 	} else								\
403 		_IF_DRAIN(ifq);						\
404 } while (0)
405 
406 #define	IFQ_PURGE(ifq)							\
407 do {									\
408 	IF_LOCK(ifq);							\
409 	IFQ_PURGE_NOLOCK(ifq);						\
410 	IF_UNLOCK(ifq);							\
411 } while (0)
412 
413 #define	IFQ_SET_READY(ifq)						\
414 	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
415 
416 #define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
417 #define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
418 #define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
419 #define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
420 #define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
421 #define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
422 #define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
423 #define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
424 
425 /*
426  * The IFF_DRV_OACTIVE test should really occur in the device driver, not in
427  * the handoff logic, as that flag is locked by the device driver.
428  */
429 #define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
430 do {									\
431 	int len;							\
432 	short mflags;							\
433 									\
434 	len = (m)->m_pkthdr.len;					\
435 	mflags = (m)->m_flags;						\
436 	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
437 	if ((err) == 0) {						\
438 		(ifp)->if_obytes += len + (adj);			\
439 		if (mflags & M_MCAST)					\
440 			(ifp)->if_omcasts++;				\
441 		if (((ifp)->if_drv_flags & IFF_DRV_OACTIVE) == 0)	\
442 			if_start(ifp);					\
443 	}								\
444 } while (0)
445 
446 #define	IFQ_HANDOFF(ifp, m, err)					\
447 	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
448 
449 #define	IFQ_DRV_DEQUEUE(ifq, m)						\
450 do {									\
451 	(m) = (ifq)->ifq_drv_head;					\
452 	if (m) {							\
453 		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
454 			(ifq)->ifq_drv_tail = NULL;			\
455 		(m)->m_nextpkt = NULL;					\
456 		(ifq)->ifq_drv_len--;					\
457 	} else {							\
458 		IFQ_LOCK(ifq);						\
459 		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
460 		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
461 			struct mbuf *m0;				\
462 			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
463 			if (m0 == NULL)					\
464 				break;					\
465 			m0->m_nextpkt = NULL;				\
466 			if ((ifq)->ifq_drv_tail == NULL)		\
467 				(ifq)->ifq_drv_head = m0;		\
468 			else						\
469 				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
470 			(ifq)->ifq_drv_tail = m0;			\
471 			(ifq)->ifq_drv_len++;				\
472 		}							\
473 		IFQ_UNLOCK(ifq);					\
474 	}								\
475 } while (0)
476 
477 #define	IFQ_DRV_PREPEND(ifq, m)						\
478 do {									\
479 	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
480 	if ((ifq)->ifq_drv_tail == NULL)				\
481 		(ifq)->ifq_drv_tail = (m);				\
482 	(ifq)->ifq_drv_head = (m);					\
483 	(ifq)->ifq_drv_len++;						\
484 } while (0)
485 
486 #define	IFQ_DRV_IS_EMPTY(ifq)						\
487 	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
488 
489 #define	IFQ_DRV_PURGE(ifq)						\
490 do {									\
491 	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
492 	while((m = n) != NULL) {					\
493 		n = m->m_nextpkt;					\
494 		m_freem(m);						\
495 	}								\
496 	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
497 	(ifq)->ifq_drv_len = 0;						\
498 	IFQ_PURGE(ifq);							\
499 } while (0)
500 
501 /*
502  * 72 was chosen below because it is the size of a TCP/IP
503  * header (40) + the minimum mss (32).
504  */
505 #define	IF_MINMTU	72
506 #define	IF_MAXMTU	65535
507 
508 #endif /* _KERNEL */
509 
510 /*
511  * The ifaddr structure contains information about one address
512  * of an interface.  They are maintained by the different address families,
513  * are allocated and attached when an address is set, and are linked
514  * together so all addresses for an interface can be located.
515  *
516  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
517  * chunk of malloc'ed memory, where we store the three addresses
518  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
519  */
520 struct ifaddr {
521 	struct	sockaddr *ifa_addr;	/* address of interface */
522 	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
523 #define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
524 	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
525 	struct	if_data if_data;	/* not all members are meaningful */
526 	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
527 	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
528 	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
529 		(int, struct rtentry *, struct rt_addrinfo *);
530 	u_short	ifa_flags;		/* mostly rt_flags for cloning */
531 	u_int	ifa_refcnt;		/* references to this structure */
532 	int	ifa_metric;		/* cost of going out this interface */
533 	int (*ifa_claim_addr)		/* check if an addr goes to this if */
534 		(struct ifaddr *, struct sockaddr *);
535 	struct mtx ifa_mtx;
536 };
537 #define	IFA_ROUTE	RTF_UP		/* route installed */
538 
539 /* for compatibility with other BSDs */
540 #define	ifa_list	ifa_link
541 
542 #define	IFA_LOCK_INIT(ifa)	\
543     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
544 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
545 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
546 #define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
547 
548 /*
549  * The prefix structure contains information about one prefix
550  * of an interface.  They are maintained by the different address families,
551  * are allocated and attached when a prefix or an address is set,
552  * and are linked together so all prefixes for an interface can be located.
553  */
554 struct ifprefix {
555 	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
556 	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
557 	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
558 	u_char	ifpr_plen;		/* prefix length in bits */
559 	u_char	ifpr_type;		/* protocol dependent prefix type */
560 };
561 
562 /*
563  * Multicast address structure.  This is analogous to the ifaddr
564  * structure except that it keeps track of multicast addresses.
565  * Also, the reference count here is a count of requests for this
566  * address, not a count of pointers to this structure.
567  */
568 struct ifmultiaddr {
569 	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
570 	struct	sockaddr *ifma_addr; 	/* address this membership is for */
571 	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
572 	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
573 	u_int	ifma_refcount;		/* reference count */
574 	void	*ifma_protospec;	/* protocol-specific state, if any */
575 };
576 
577 #ifdef _KERNEL
578 #define	IFAFREE(ifa)					\
579 	do {						\
580 		IFA_LOCK(ifa);				\
581 		KASSERT((ifa)->ifa_refcnt > 0,		\
582 		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
583 		if (--(ifa)->ifa_refcnt == 0) {		\
584 			IFA_DESTROY(ifa);		\
585 			free(ifa, M_IFADDR);		\
586 		} else 					\
587 			IFA_UNLOCK(ifa);		\
588 	} while (0)
589 
590 #define IFAREF(ifa)					\
591 	do {						\
592 		IFA_LOCK(ifa);				\
593 		++(ifa)->ifa_refcnt;			\
594 		IFA_UNLOCK(ifa);			\
595 	} while (0)
596 
597 extern	struct mtx ifnet_lock;
598 #define	IFNET_LOCK_INIT() \
599     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
600 #define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
601 #define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
602 #define	IFNET_RLOCK()		IFNET_WLOCK()
603 #define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
604 
605 struct ifindex_entry {
606 	struct	ifnet *ife_ifnet;
607 	struct	ifaddr *ife_ifnet_addr;
608 	struct cdev *ife_dev;
609 };
610 
611 #define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
612 /*
613  * Given the index, ifaddr_byindex() returns the one and only
614  * link-level ifaddr for the interface. You are not supposed to use
615  * it to traverse the list of addresses associated to the interface.
616  */
617 #define ifaddr_byindex(idx)	ifindex_table[(idx)].ife_ifnet_addr
618 #define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
619 
620 extern	struct ifnethead ifnet;
621 extern	struct ifindex_entry *ifindex_table;
622 extern	int ifqmaxlen;
623 extern	struct ifnet *loif;	/* first loopback interface */
624 extern	int if_index;
625 
626 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
627 int	if_allmulti(struct ifnet *, int);
628 struct	ifnet* if_alloc(u_char);
629 void	if_attach(struct ifnet *);
630 int	if_delmulti(struct ifnet *, struct sockaddr *);
631 void	if_detach(struct ifnet *);
632 void	if_purgeaddrs(struct ifnet *);
633 void	if_down(struct ifnet *);
634 void	if_free(struct ifnet *);
635 void	if_free_type(struct ifnet *, u_char);
636 void	if_initname(struct ifnet *, const char *, int);
637 void	if_link_state_change(struct ifnet *, int);
638 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
639 int	if_setlladdr(struct ifnet *, const u_char *, int);
640 void	if_up(struct ifnet *);
641 /*void	ifinit(void);*/ /* declared in systm.h for main() */
642 int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
643 int	ifpromisc(struct ifnet *, int);
644 struct	ifnet *ifunit(const char *);
645 
646 struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
647 struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
648 struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
649 struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
650 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
651 
652 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
653 
654 typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
655 typedef	void if_com_free_t(void *com, u_char type);
656 void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
657 void	if_deregister_com_alloc(u_char type);
658 
659 #define IF_LLADDR(ifp)							\
660     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
661 
662 #ifdef DEVICE_POLLING
663 enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
664 
665 typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
666 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
667 int    ether_poll_deregister(struct ifnet *ifp);
668 #endif /* DEVICE_POLLING */
669 
670 #endif /* _KERNEL */
671 
672 #endif /* !_NET_IF_VAR_H_ */
673