if_llatbl.h revision 337462 
1/*
2 * Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
3 * Copyright (c) 2004-2008 Qing Li. All rights reserved.
4 * Copyright (c) 2008 Kip Macy. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/sys/net/if_llatbl.h 337462 2018-08-08 16:17:50Z ae $");
29
30#ifndef	_NET_IF_LLATBL_H_
31#define	_NET_IF_LLATBL_H_
32
33#include <sys/_rwlock.h>
34#include <netinet/in.h>
35
36struct ifnet;
37struct sysctl_req;
38struct rt_msghdr;
39struct rt_addrinfo;
40
41struct llentry;
42LIST_HEAD(llentries, llentry);
43
44extern struct rwlock lltable_rwlock;
45#define	LLTABLE_RLOCK()		rw_rlock(&lltable_rwlock)
46#define	LLTABLE_RUNLOCK()	rw_runlock(&lltable_rwlock)
47#define	LLTABLE_WLOCK()		rw_wlock(&lltable_rwlock)
48#define	LLTABLE_WUNLOCK()	rw_wunlock(&lltable_rwlock)
49#define	LLTABLE_LOCK_ASSERT()	rw_assert(&lltable_rwlock, RA_LOCKED)
50
51#define	LLE_MAX_LINKHDR		24	/* Full IB header */
52/*
53 * Code referencing llentry must at least hold
54 * a shared lock
55 */
56struct llentry {
57	LIST_ENTRY(llentry)	 lle_next;
58	union {
59		struct in_addr	addr4;
60		struct in6_addr	addr6;
61	} r_l3addr;
62	char			r_linkdata[LLE_MAX_LINKHDR]; /* L2 data */
63	uint8_t			r_hdrlen;	/* length for LL header */
64	uint8_t			spare0[3];
65	uint16_t		r_flags;	/* LLE runtime flags */
66	uint16_t		r_skip_req;	/* feedback from fast path */
67
68	struct lltable		 *lle_tbl;
69	struct llentries	 *lle_head;
70	void			(*lle_free)(struct llentry *);
71	struct mbuf		 *la_hold;
72	int			 la_numheld;  /* # of packets currently held */
73	time_t			 la_expire;
74	uint16_t		 la_flags;
75	uint16_t		 la_asked;
76	uint16_t		 la_preempt;
77	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
78	uint16_t		 ln_router;
79	time_t			 ln_ntick;
80	time_t			lle_remtime;	/* Real time remaining */
81	time_t			lle_hittime;	/* Time when r_skip_req was unset */
82	int			 lle_refcnt;
83	char			*ll_addr;	/* link-layer address */
84
85	LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
86	struct callout		lle_timer;
87	struct rwlock		 lle_lock;
88	struct mtx		req_mtx;
89};
90
91#define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
92#define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
93#define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
94#define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
95#define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
96#define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
97#define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
98#define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
99#define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
100
101#define	LLE_REQ_INIT(lle)	mtx_init(&(lle)->req_mtx, "lle req", \
102	NULL, MTX_DEF)
103#define	LLE_REQ_DESTROY(lle)	mtx_destroy(&(lle)->req_mtx)
104#define	LLE_REQ_LOCK(lle)	mtx_lock(&(lle)->req_mtx)
105#define	LLE_REQ_UNLOCK(lle)	mtx_unlock(&(lle)->req_mtx)
106
107#define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
108
109#define	LLE_ADDREF(lle) do {					\
110	LLE_WLOCK_ASSERT(lle);					\
111	KASSERT((lle)->lle_refcnt >= 0,				\
112	    ("negative refcnt %d on lle %p",			\
113	    (lle)->lle_refcnt, (lle)));				\
114	(lle)->lle_refcnt++;					\
115} while (0)
116
117#define	LLE_REMREF(lle)	do {					\
118	LLE_WLOCK_ASSERT(lle);					\
119	KASSERT((lle)->lle_refcnt > 0,				\
120	    ("bogus refcnt %d on lle %p",			\
121	    (lle)->lle_refcnt, (lle)));				\
122	(lle)->lle_refcnt--;					\
123} while (0)
124
125#define	LLE_FREE_LOCKED(lle) do {				\
126	if ((lle)->lle_refcnt == 1)				\
127		(lle)->lle_free(lle);				\
128	else {							\
129		LLE_REMREF(lle);				\
130		LLE_WUNLOCK(lle);				\
131	}							\
132	/* guard against invalid refs */			\
133	(lle) = NULL;						\
134} while (0)
135
136#define	LLE_FREE(lle) do {					\
137	LLE_WLOCK(lle);						\
138	LLE_FREE_LOCKED(lle);					\
139} while (0)
140
141typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
142    const struct sockaddr *l3addr);
143typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
144    const struct sockaddr *l3addr);
145typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
146typedef void (llt_prefix_free_t)(struct lltable *,
147    const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
148typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
149    struct sysctl_req *);
150typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
151typedef int (llt_match_prefix_t)(const struct sockaddr *,
152    const struct sockaddr *, u_int, struct llentry *);
153typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
154typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
155typedef void (llt_free_tbl_t)(struct lltable *);
156typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
157typedef void (llt_unlink_entry_t)(struct llentry *);
158typedef void (llt_mark_used_t)(struct llentry *);
159
160typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
161typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
162
163struct lltable {
164	SLIST_ENTRY(lltable)	llt_link;
165	int			llt_af;
166	int			llt_hsize;
167	struct llentries	*lle_head;
168	struct ifnet		*llt_ifp;
169
170	llt_lookup_t		*llt_lookup;
171	llt_alloc_t		*llt_alloc_entry;
172	llt_delete_t		*llt_delete_entry;
173	llt_prefix_free_t	*llt_prefix_free;
174	llt_dump_entry_t	*llt_dump_entry;
175	llt_hash_t		*llt_hash;
176	llt_match_prefix_t	*llt_match_prefix;
177	llt_free_entry_t	*llt_free_entry;
178	llt_foreach_entry_t	*llt_foreach_entry;
179	llt_link_entry_t	*llt_link_entry;
180	llt_unlink_entry_t	*llt_unlink_entry;
181	llt_fill_sa_entry_t	*llt_fill_sa_entry;
182	llt_free_tbl_t		*llt_free_tbl;
183	llt_mark_used_t		*llt_mark_used;
184};
185
186MALLOC_DECLARE(M_LLTABLE);
187
188/*
189 * LLentry flags
190 */
191#define	LLE_DELETED	0x0001	/* entry must be deleted */
192#define	LLE_STATIC	0x0002	/* entry is static */
193#define	LLE_IFADDR	0x0004	/* entry is interface addr */
194#define	LLE_VALID	0x0008	/* ll_addr is valid */
195#define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
196#define	LLE_PUB		0x0020	/* publish entry ??? */
197#define	LLE_LINKED	0x0040	/* linked to lookup structure */
198/* LLE request flags */
199#define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
200#define	LLE_UNLOCKED	0x4000	/* return lle unlocked */
201#define	LLE_ADDRONLY	0x4000	/* return lladdr instead of full header */
202#define	LLE_CREATE	0x8000	/* hint to avoid lle lookup */
203
204/* LLE flags used by fastpath code */
205#define	RLLE_VALID	0x0001		/* entry is valid */
206#define	RLLE_IFADDR	LLE_IFADDR	/* entry is ifaddr */
207
208#define LLATBL_HASH(key, mask) \
209	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
210
211struct lltable *lltable_allocate_htbl(uint32_t hsize);
212void		lltable_free(struct lltable *);
213void		lltable_link(struct lltable *llt);
214void		lltable_prefix_free(int, struct sockaddr *,
215		    struct sockaddr *, u_int);
216#if 0
217void		lltable_drain(int);
218#endif
219int		lltable_sysctl_dumparp(int, struct sysctl_req *);
220
221size_t		llentry_free(struct llentry *);
222struct llentry  *llentry_alloc(struct ifnet *, struct lltable *,
223		    struct sockaddr_storage *);
224
225/* helper functions */
226size_t lltable_drop_entry_queue(struct llentry *);
227void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
228    const char *linkhdr, size_t linkhdrsize, int lladdr_off);
229int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
230    const char *linkhdr, size_t linkhdrsize, int lladdr_off);
231
232int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
233    char *buf, size_t *bufsize, int *lladdr_off);
234void lltable_update_ifaddr(struct lltable *llt);
235struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
236    const struct sockaddr *l4addr);
237void lltable_free_entry(struct lltable *llt, struct llentry *lle);
238int lltable_delete_addr(struct lltable *llt, u_int flags,
239    const struct sockaddr *l3addr);
240void lltable_link_entry(struct lltable *llt, struct llentry *lle);
241void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
242void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
243struct ifnet *lltable_get_ifp(const struct lltable *llt);
244int lltable_get_af(const struct lltable *llt);
245
246int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
247    void *farg);
248/*
249 * Generic link layer address lookup function.
250 */
251static __inline struct llentry *
252lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
253{
254
255	return (llt->llt_lookup(llt, flags, l3addr));
256}
257
258/*
259 * Notify the LLE code that the entry was used by datapath.
260 */
261static __inline void
262llentry_mark_used(struct llentry *lle)
263{
264
265	if (lle->r_skip_req == 0)
266		return;
267	if ((lle->r_flags & RLLE_VALID) != 0)
268		lle->lle_tbl->llt_mark_used(lle);
269}
270
271int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
272
273#include <sys/eventhandler.h>
274enum {
275	LLENTRY_RESOLVED,
276	LLENTRY_TIMEDOUT,
277	LLENTRY_DELETED,
278	LLENTRY_EXPIRED,
279};
280typedef void (*lle_event_fn)(void *, struct llentry *, int);
281EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
282#endif  /* _NET_IF_LLATBL_H_ */
283