if_var.h revision 133261
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: head/sys/net/if_var.h 133261 2004-08-07 09:32:04Z mlaier $
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 */
65struct	mbuf;
66struct	thread;
67struct	rtentry;
68struct	rt_addrinfo;
69struct	socket;
70struct	ether_header;
71#endif
72
73#include <sys/queue.h>		/* get TAILQ macros */
74
75#ifdef _KERNEL
76#include <sys/mbuf.h>
77#include <sys/eventhandler.h>
78#endif /* _KERNEL */
79#include <sys/lock.h>		/* XXX */
80#include <sys/mutex.h>		/* XXX */
81#include <sys/event.h>		/* XXX */
82#include <sys/_task.h>
83
84#define	IF_DUNIT_NONE	-1
85
86#if 1 /* ALTQ */
87#include <altq/if_altq.h>
88#endif
89
90TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
91TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
92TAILQ_HEAD(ifprefixhead, ifprefix);
93TAILQ_HEAD(ifmultihead, ifmultiaddr);
94
95/*
96 * Structure defining a queue for a network interface.
97 */
98struct	ifqueue {
99	struct	mbuf *ifq_head;
100	struct	mbuf *ifq_tail;
101	int	ifq_len;
102	int	ifq_maxlen;
103	int	ifq_drops;
104	struct	mtx ifq_mtx;
105};
106
107/*
108 * Structure defining a network interface.
109 *
110 * (Would like to call this struct ``if'', but C isn't PL/1.)
111 */
112
113/*
114 * NB: For FreeBSD, it is assumed that each NIC driver's softc starts with
115 * one of these structures, typically held within an arpcom structure.
116 *
117 *	struct <foo>_softc {
118 *		struct arpcom {
119 *			struct  ifnet ac_if;
120 *			...
121 *		} <arpcom> ;
122 *		...
123 *	};
124 *
125 * The assumption is used in a number of places, including many
126 * files in sys/net, device drivers, and sys/dev/mii.c:miibus_attach().
127 *
128 * Unfortunately devices' softc are opaque, so we depend on this layout
129 * to locate the struct ifnet from the softc in the generic code.
130 *
131 */
132struct ifnet {
133	void	*if_softc;		/* pointer to driver state */
134	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
135	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
136	const char *if_dname;		/* driver name */
137	int	if_dunit;		/* unit or IF_DUNIT_NONE */
138	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
139		/*
140		 * if_addrhead is the list of all addresses associated to
141		 * an interface.
142		 * Some code in the kernel assumes that first element
143		 * of the list has type AF_LINK, and contains sockaddr_dl
144		 * addresses which store the link-level address and the name
145		 * of the interface.
146		 * However, access to the AF_LINK address through this
147		 * field is deprecated. Use ifaddr_byindex() instead.
148		 */
149	struct	klist if_klist;		/* events attached to this if */
150	int	if_pcount;		/* number of promiscuous listeners */
151	void	*if_carp;		/* carp (tbd) interface pointer */
152	struct	bpf_if *if_bpf;		/* packet filter structure */
153	u_short	if_index;		/* numeric abbreviation for this if  */
154	short	if_timer;		/* time 'til if_watchdog called */
155	u_short	if_nvlans;		/* number of active vlans */
156	int	if_flags;		/* up/down, broadcast, etc. */
157	int	if_capabilities;	/* interface capabilities */
158	int	if_capenable;		/* enabled features */
159	void	*if_linkmib;		/* link-type-specific MIB data */
160	size_t	if_linkmiblen;		/* length of above data */
161	struct	if_data if_data;
162	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
163	int	if_amcount;		/* number of all-multicast requests */
164/* procedure handles */
165	int	(*if_output)		/* output routine (enqueue) */
166		(struct ifnet *, struct mbuf *, struct sockaddr *,
167		     struct rtentry *);
168	void	(*if_input)		/* input routine (from h/w driver) */
169		(struct ifnet *, struct mbuf *);
170	void	(*if_start)		/* initiate output routine */
171		(struct ifnet *);
172	int	(*if_ioctl)		/* ioctl routine */
173		(struct ifnet *, u_long, caddr_t);
174	void	(*if_watchdog)		/* timer routine */
175		(struct ifnet *);
176	void	(*if_init)		/* Init routine */
177		(void *);
178	int	(*if_resolvemulti)	/* validate/resolve multicast */
179		(struct ifnet *, struct sockaddr **, struct sockaddr *);
180#if 1 /* ALTQ */
181	struct  ifaltq if_snd;		/* output queue (includes altq) */
182#else
183	struct	ifqueue if_snd;		/* output queue */
184#endif
185	const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
186
187	struct	lltable *lltables;	/* list of L3-L2 resolution tables */
188
189	struct	label *if_label;	/* interface MAC label */
190
191	/* these are only used by IPv6 */
192	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
193	void	*if_afdata[AF_MAX];
194	int	if_afdata_initialized;
195	struct	mtx if_afdata_mtx;
196	struct	task if_starttask;	/* task for IFF_NEEDSGIANT */
197};
198
199typedef void if_init_f_t(void *);
200
201/*
202 * XXX These aliases are terribly dangerous because they could apply
203 * to anything.
204 */
205#define	if_mtu		if_data.ifi_mtu
206#define	if_type		if_data.ifi_type
207#define if_physical	if_data.ifi_physical
208#define	if_addrlen	if_data.ifi_addrlen
209#define	if_hdrlen	if_data.ifi_hdrlen
210#define	if_metric	if_data.ifi_metric
211#define	if_link_state	if_data.ifi_link_state
212#define	if_baudrate	if_data.ifi_baudrate
213#define	if_hwassist	if_data.ifi_hwassist
214#define	if_ipackets	if_data.ifi_ipackets
215#define	if_ierrors	if_data.ifi_ierrors
216#define	if_opackets	if_data.ifi_opackets
217#define	if_oerrors	if_data.ifi_oerrors
218#define	if_collisions	if_data.ifi_collisions
219#define	if_ibytes	if_data.ifi_ibytes
220#define	if_obytes	if_data.ifi_obytes
221#define	if_imcasts	if_data.ifi_imcasts
222#define	if_omcasts	if_data.ifi_omcasts
223#define	if_iqdrops	if_data.ifi_iqdrops
224#define	if_noproto	if_data.ifi_noproto
225#define	if_lastchange	if_data.ifi_lastchange
226#define if_recvquota	if_data.ifi_recvquota
227#define	if_xmitquota	if_data.ifi_xmitquota
228#define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)0)
229
230/* for compatibility with other BSDs */
231#define	if_addrlist	if_addrhead
232#define	if_list		if_link
233
234/*
235 * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
236 * are queues of messages stored on ifqueue structures
237 * (defined above).  Entries are added to and deleted from these structures
238 * by these macros, which should be called with ipl raised to splimp().
239 */
240#define IF_LOCK(ifq)		mtx_lock(&(ifq)->ifq_mtx)
241#define IF_UNLOCK(ifq)		mtx_unlock(&(ifq)->ifq_mtx)
242#define	IF_LOCK_ASSERT(ifq)	mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
243#define	_IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
244#define	_IF_DROP(ifq)		((ifq)->ifq_drops++)
245#define	_IF_QLEN(ifq)		((ifq)->ifq_len)
246
247#define	_IF_ENQUEUE(ifq, m) do { 				\
248	(m)->m_nextpkt = NULL;					\
249	if ((ifq)->ifq_tail == NULL) 				\
250		(ifq)->ifq_head = m; 				\
251	else 							\
252		(ifq)->ifq_tail->m_nextpkt = m; 		\
253	(ifq)->ifq_tail = m; 					\
254	(ifq)->ifq_len++; 					\
255} while (0)
256
257#define IF_ENQUEUE(ifq, m) do {					\
258	IF_LOCK(ifq); 						\
259	_IF_ENQUEUE(ifq, m); 					\
260	IF_UNLOCK(ifq); 					\
261} while (0)
262
263#define	_IF_PREPEND(ifq, m) do {				\
264	(m)->m_nextpkt = (ifq)->ifq_head; 			\
265	if ((ifq)->ifq_tail == NULL) 				\
266		(ifq)->ifq_tail = (m); 				\
267	(ifq)->ifq_head = (m); 					\
268	(ifq)->ifq_len++; 					\
269} while (0)
270
271#define IF_PREPEND(ifq, m) do {		 			\
272	IF_LOCK(ifq); 						\
273	_IF_PREPEND(ifq, m); 					\
274	IF_UNLOCK(ifq); 					\
275} while (0)
276
277#define	_IF_DEQUEUE(ifq, m) do { 				\
278	(m) = (ifq)->ifq_head; 					\
279	if (m) { 						\
280		if (((ifq)->ifq_head = (m)->m_nextpkt) == 0) 	\
281			(ifq)->ifq_tail = NULL; 		\
282		(m)->m_nextpkt = NULL; 				\
283		(ifq)->ifq_len--; 				\
284	} 							\
285} while (0)
286
287#define IF_DEQUEUE(ifq, m) do { 				\
288	IF_LOCK(ifq); 						\
289	_IF_DEQUEUE(ifq, m); 					\
290	IF_UNLOCK(ifq); 					\
291} while (0)
292
293#define	_IF_POLL(ifq, m)	((m) = (ifq)->ifq_head)
294#define	IF_POLL(ifq, m)		_IF_POLL(ifq, m)
295
296#define _IF_DRAIN(ifq) do { 					\
297	struct mbuf *m; 					\
298	for (;;) { 						\
299		_IF_DEQUEUE(ifq, m); 				\
300		if (m == NULL) 					\
301			break; 					\
302		m_freem(m); 					\
303	} 							\
304} while (0)
305
306#define IF_DRAIN(ifq) do {					\
307	IF_LOCK(ifq);						\
308	_IF_DRAIN(ifq);						\
309	IF_UNLOCK(ifq);						\
310} while(0)
311
312#ifdef _KERNEL
313/* interface address change event */
314typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
315EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
316/* new interface arrival event */
317typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
318EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
319/* interface departure event */
320typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
321EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
322
323#define	IF_AFDATA_LOCK_INIT(ifp)	\
324    mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
325#define	IF_AFDATA_LOCK(ifp)	mtx_lock(&(ifp)->if_afdata_mtx)
326#define	IF_AFDATA_TRYLOCK(ifp)	mtx_trylock(&(ifp)->if_afdata_mtx)
327#define	IF_AFDATA_UNLOCK(ifp)	mtx_unlock(&(ifp)->if_afdata_mtx)
328#define	IF_AFDATA_DESTROY(ifp)	mtx_destroy(&(ifp)->if_afdata_mtx)
329
330#define	IF_HANDOFF(ifq, m, ifp)			\
331	if_handoff((struct ifqueue *)ifq, m, ifp, 0)
332#define	IF_HANDOFF_ADJ(ifq, m, ifp, adj)	\
333	if_handoff((struct ifqueue *)ifq, m, ifp, adj)
334
335void	if_start(struct ifnet *);
336
337static __inline int
338if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp, int adjust)
339{
340	int active = 0;
341
342	IF_LOCK(ifq);
343	if (_IF_QFULL(ifq)) {
344		_IF_DROP(ifq);
345		IF_UNLOCK(ifq);
346		m_freem(m);
347		return (0);
348	}
349	if (ifp != NULL) {
350		ifp->if_obytes += m->m_pkthdr.len + adjust;
351		if (m->m_flags & (M_BCAST|M_MCAST))
352			ifp->if_omcasts++;
353		active = ifp->if_flags & IFF_OACTIVE;
354	}
355	_IF_ENQUEUE(ifq, m);
356	IF_UNLOCK(ifq);
357	if (ifp != NULL && !active)
358		if_start(ifp);
359	return (1);
360}
361#if 1 /* ALTQ */
362#define	IFQ_ENQUEUE(ifq, m, err)					\
363do {									\
364	IF_LOCK(ifq);							\
365	if (ALTQ_IS_ENABLED(ifq))					\
366		ALTQ_ENQUEUE(ifq, m, NULL, err);			\
367	else {								\
368		if (_IF_QFULL(ifq)) {					\
369			m_freem(m);					\
370			(err) = ENOBUFS;				\
371		} else {						\
372			_IF_ENQUEUE(ifq, m);				\
373			(err) = 0;					\
374		}							\
375	}								\
376	if (err)							\
377		(ifq)->ifq_drops++;					\
378	IF_UNLOCK(ifq);							\
379} while (0)
380
381#define	IFQ_DEQUEUE_NOLOCK(ifq, m)					\
382do {									\
383	if (TBR_IS_ENABLED(ifq))					\
384		(m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);		\
385	else if (ALTQ_IS_ENABLED(ifq))					\
386		ALTQ_DEQUEUE(ifq, m);					\
387	else								\
388		_IF_DEQUEUE(ifq, m);					\
389} while (0)
390
391#define	IFQ_DEQUEUE(ifq, m)						\
392do {									\
393	IF_LOCK(ifq);							\
394	IFQ_DEQUEUE_NOLOCK(ifq, m);					\
395	IF_UNLOCK(ifq);							\
396} while (0)
397
398#define	IFQ_POLL_NOLOCK(ifq, m)						\
399do {									\
400	if (TBR_IS_ENABLED(ifq))					\
401		(m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);			\
402	else if (ALTQ_IS_ENABLED(ifq))					\
403		ALTQ_POLL(ifq, m);					\
404	else								\
405		_IF_POLL(ifq, m);					\
406} while (0)
407
408#define	IFQ_POLL(ifq, m)						\
409do {									\
410	IF_LOCK(ifq);							\
411	IFQ_POLL_NOLOCK(ifq, m);					\
412	IF_UNLOCK(ifq);							\
413} while (0)
414
415#define	IFQ_PURGE_NOLOCK(ifq)						\
416do {									\
417	if (ALTQ_IS_ENABLED(ifq)) {					\
418		ALTQ_PURGE(ifq);					\
419	} else								\
420		_IF_DRAIN(ifq);						\
421} while (0)
422
423#define	IFQ_PURGE(ifq)							\
424do {									\
425	IF_LOCK(ifq);							\
426	IFQ_PURGE_NOLOCK(ifq);						\
427	IF_UNLOCK(ifq);							\
428} while (0)
429
430#define	IFQ_SET_READY(ifq)						\
431	do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
432
433#else /* !ALTQ */
434#define	IFQ_ENQUEUE(ifq, m, err)					\
435do {									\
436	IF_LOCK(ifq);							\
437	if (_IF_QFULL(ifq)) {						\
438		m_freem(m);						\
439		(err) = ENOBUFS;					\
440	} else {							\
441		_IF_ENQUEUE(ifq, m);					\
442		(err) = 0;						\
443	}								\
444	if (err)							\
445		(ifq)->ifq_drops++;					\
446	IF_UNLOCK(ifq);							\
447} while (0)
448
449#define	IFQ_DEQUEUE_NOLOCK(ifq, m)	_IF_DEQUEUE(ifq, m)
450#define	IFQ_DEQUEUE(ifq, m)		IF_DEQUEUE(ifq, m)
451#define	IFQ_POLL_NOLOCK(ifq, m)		_IF_POLL(ifq, m)
452#define	IFQ_POLL(ifq, m)		IF_POLL(ifq, m)
453#define	IFQ_PURGE_NOLOCK(ifq)		_IF_DRAIN(ifq)
454#define	IFQ_PURGE(ifq)			IF_DRAIN(ifq)
455
456#define	IFQ_SET_READY(ifq)		/* nothing */
457
458#endif /* !ALTQ */
459
460#define	IFQ_LOCK(ifq)			IF_LOCK(ifq)
461#define	IFQ_UNLOCK(ifq)			IF_UNLOCK(ifq)
462#define	IFQ_LOCK_ASSERT(ifq)		IF_LOCK_ASSERT(ifq)
463#define	IFQ_IS_EMPTY(ifq)		((ifq)->ifq_len == 0)
464#define	IFQ_INC_LEN(ifq)		((ifq)->ifq_len++)
465#define	IFQ_DEC_LEN(ifq)		(--(ifq)->ifq_len)
466#define	IFQ_INC_DROPS(ifq)		((ifq)->ifq_drops++)
467#define	IFQ_SET_MAXLEN(ifq, len)	((ifq)->ifq_maxlen = (len))
468
469#define	IFQ_HANDOFF_ADJ(ifp, m, adj, err)				\
470do {									\
471	int len;							\
472	short mflags;							\
473									\
474	len = (m)->m_pkthdr.len;					\
475	mflags = (m)->m_flags;						\
476	IFQ_ENQUEUE(&(ifp)->if_snd, m, err);				\
477	if ((err) == 0) {						\
478		(ifp)->if_obytes += len + (adj);			\
479		if (mflags & M_MCAST)					\
480			(ifp)->if_omcasts++;				\
481		if (((ifp)->if_flags & IFF_OACTIVE) == 0)		\
482			if_start(ifp);					\
483	}								\
484} while (0)
485
486#define	IFQ_HANDOFF(ifp, m, err)					\
487	IFQ_HANDOFF_ADJ(ifp, m, 0, err)
488
489#define	IFQ_DRV_DEQUEUE(ifq, m)						\
490do {									\
491	(m) = (ifq)->ifq_drv_head;					\
492	if (m) {							\
493		if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)	\
494			(ifq)->ifq_drv_tail = NULL;			\
495		(m)->m_nextpkt = NULL;					\
496		(ifq)->ifq_drv_len--;					\
497	} else {							\
498		IFQ_LOCK(ifq);						\
499		IFQ_DEQUEUE_NOLOCK(ifq, m);				\
500		while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {	\
501			struct mbuf *m0;				\
502			IFQ_DEQUEUE_NOLOCK(ifq, m0);			\
503			if (m0 == NULL)					\
504				break;					\
505			m0->m_nextpkt = NULL;				\
506			if ((ifq)->ifq_drv_tail == NULL)		\
507				(ifq)->ifq_drv_head = m0;		\
508			else						\
509				(ifq)->ifq_drv_tail->m_nextpkt = m0;	\
510			(ifq)->ifq_drv_tail = m0;			\
511			(ifq)->ifq_drv_len++;				\
512		}							\
513		IFQ_UNLOCK(ifq);					\
514	}								\
515} while (0)
516
517#define	IFQ_DRV_PREPEND(ifq, m)						\
518do {									\
519	(m)->m_nextpkt = (ifq)->ifq_drv_head;				\
520	if ((ifq)->ifq_drv_tail == NULL)				\
521		(ifq)->ifq_drv_tail = (m);				\
522	(ifq)->ifq_drv_head = (m);					\
523	(ifq)->ifq_drv_len++;						\
524} while (0)
525
526#define	IFQ_DRV_IS_EMPTY(ifq)						\
527	(((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
528
529#define	IFQ_DRV_PURGE(ifq)						\
530do {									\
531	struct mbuf *m, *n = (ifq)->ifq_drv_head;			\
532	while((m = n) != NULL) {					\
533		n = m->m_nextpkt;					\
534		m_freem(m);						\
535	}								\
536	(ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;		\
537	(ifq)->ifq_drv_len = 0;						\
538	IFQ_PURGE(ifq);							\
539} while (0)
540
541/*
542 * 72 was chosen below because it is the size of a TCP/IP
543 * header (40) + the minimum mss (32).
544 */
545#define	IF_MINMTU	72
546#define	IF_MAXMTU	65535
547
548#endif /* _KERNEL */
549
550/*
551 * The ifaddr structure contains information about one address
552 * of an interface.  They are maintained by the different address families,
553 * are allocated and attached when an address is set, and are linked
554 * together so all addresses for an interface can be located.
555 *
556 * NOTE: a 'struct ifaddr' is always at the beginning of a larger
557 * chunk of malloc'ed memory, where we store the three addresses
558 * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
559 */
560struct ifaddr {
561	struct	sockaddr *ifa_addr;	/* address of interface */
562	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
563#define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
564	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
565	struct	if_data if_data;	/* not all members are meaningful */
566	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
567	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
568	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
569		(int, struct rtentry *, struct rt_addrinfo *);
570	u_short	ifa_flags;		/* mostly rt_flags for cloning */
571	u_int	ifa_refcnt;		/* references to this structure */
572	int	ifa_metric;		/* cost of going out this interface */
573	int (*ifa_claim_addr)		/* check if an addr goes to this if */
574		(struct ifaddr *, struct sockaddr *);
575	struct mtx ifa_mtx;
576};
577#define	IFA_ROUTE	RTF_UP		/* route installed */
578
579/* for compatibility with other BSDs */
580#define	ifa_list	ifa_link
581
582#define	IFA_LOCK_INIT(ifa)	\
583    mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
584#define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
585#define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
586#define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
587
588/*
589 * The prefix structure contains information about one prefix
590 * of an interface.  They are maintained by the different address families,
591 * are allocated and attached when a prefix or an address is set,
592 * and are linked together so all prefixes for an interface can be located.
593 */
594struct ifprefix {
595	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
596	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
597	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
598	u_char	ifpr_plen;		/* prefix length in bits */
599	u_char	ifpr_type;		/* protocol dependent prefix type */
600};
601
602/*
603 * Multicast address structure.  This is analogous to the ifaddr
604 * structure except that it keeps track of multicast addresses.
605 * Also, the reference count here is a count of requests for this
606 * address, not a count of pointers to this structure.
607 */
608struct ifmultiaddr {
609	TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
610	struct	sockaddr *ifma_addr; 	/* address this membership is for */
611	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
612	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
613	u_int	ifma_refcount;		/* reference count */
614	void	*ifma_protospec;	/* protocol-specific state, if any */
615};
616
617#ifdef _KERNEL
618#define	IFAFREE(ifa)					\
619	do {						\
620		IFA_LOCK(ifa);				\
621		KASSERT((ifa)->ifa_refcnt > 0,		\
622		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
623		if (--(ifa)->ifa_refcnt == 0) {		\
624			IFA_DESTROY(ifa);		\
625			free(ifa, M_IFADDR);		\
626		} else 					\
627			IFA_UNLOCK(ifa);		\
628	} while (0)
629
630#define IFAREF(ifa)					\
631	do {						\
632		IFA_LOCK(ifa);				\
633		++(ifa)->ifa_refcnt;			\
634		IFA_UNLOCK(ifa);			\
635	} while (0)
636
637extern	struct mtx ifnet_lock;
638#define	IFNET_LOCK_INIT() \
639    mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
640#define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
641#define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
642#define	IFNET_RLOCK()		IFNET_WLOCK()
643#define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
644
645struct ifindex_entry {
646	struct	ifnet *ife_ifnet;
647	struct	ifaddr *ife_ifnet_addr;
648	struct cdev *ife_dev;
649};
650
651#define ifnet_byindex(idx)	ifindex_table[(idx)].ife_ifnet
652/*
653 * Given the index, ifaddr_byindex() returns the one and only
654 * link-level ifaddr for the interface. You are not supposed to use
655 * it to traverse the list of addresses associated to the interface.
656 */
657#define ifaddr_byindex(idx)	ifindex_table[(idx)].ife_ifnet_addr
658#define ifdev_byindex(idx)	ifindex_table[(idx)].ife_dev
659
660extern	struct ifnethead ifnet;
661extern	struct ifindex_entry *ifindex_table;
662extern	int ifqmaxlen;
663extern	struct ifnet *loif;	/* first loopback interface */
664extern	int if_index;
665
666int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
667int	if_allmulti(struct ifnet *, int);
668void	if_attach(struct ifnet *);
669int	if_delmulti(struct ifnet *, struct sockaddr *);
670void	if_detach(struct ifnet *);
671void	if_down(struct ifnet *);
672void	if_initname(struct ifnet *, const char *, int);
673int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
674int	if_setlladdr(struct ifnet *, const u_char *, int);
675void	if_up(struct ifnet *);
676/*void	ifinit(void);*/ /* declared in systm.h for main() */
677int	ifioctl(struct socket *, u_long, caddr_t, struct thread *);
678int	ifpromisc(struct ifnet *, int);
679struct	ifnet *ifunit(const char *);
680
681struct	ifaddr *ifa_ifwithaddr(struct sockaddr *);
682struct	ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
683struct	ifaddr *ifa_ifwithnet(struct sockaddr *);
684struct	ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
685struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
686
687struct	ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
688int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
689
690#define IF_LLADDR(ifp)							\
691    LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
692
693#ifdef DEVICE_POLLING
694enum poll_cmd {	POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
695
696typedef	void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
697int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
698int    ether_poll_deregister(struct ifnet *ifp);
699#endif /* DEVICE_POLLING */
700
701#endif /* _KERNEL */
702
703#endif /* !_NET_IF_VAR_H_ */
704