xref: /freebsd/sys/net/if_llatbl.h (revision 5ca34122ecdd5abc62bdae39663fec9ac8523d87)
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("$FreeBSD$");
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 
36 struct ifnet;
37 struct sysctl_req;
38 struct rt_msghdr;
39 struct rt_addrinfo;
40 
41 struct llentry;
42 LIST_HEAD(llentries, llentry);
43 
44 extern 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 /*
52  * Code referencing llentry must at least hold
53  * a shared lock
54  */
55 struct llentry {
56 	LIST_ENTRY(llentry)	 lle_next;
57 	union {
58 		struct in_addr	addr4;
59 		struct in6_addr	addr6;
60 	} r_l3addr;
61 	union {
62 		uint64_t	mac_aligned;
63 		uint16_t	mac16[3];
64 		uint8_t		mac8[20];	/* IB needs 20 bytes. */
65 	} ll_addr;
66 	uint32_t		spare0;
67 	uint64_t		spare1;
68 
69 	struct lltable		 *lle_tbl;
70 	struct llentries	 *lle_head;
71 	void			(*lle_free)(struct llentry *);
72 	struct mbuf		 *la_hold;
73 	int			 la_numheld;  /* # of packets currently held */
74 	time_t			 la_expire;
75 	uint16_t		 la_flags;
76 	uint16_t		 la_asked;
77 	uint16_t		 la_preempt;
78 	uint16_t		 ln_byhint;
79 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
80 	uint16_t		 ln_router;
81 	time_t			 ln_ntick;
82 	int			 lle_refcnt;
83 
84 	LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
85 	struct callout		lle_timer;
86 	struct rwlock		 lle_lock;
87 };
88 
89 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
90 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
91 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
92 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
93 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
94 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
95 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
96 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
97 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
98 
99 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
100 
101 #define	LLE_ADDREF(lle) do {					\
102 	LLE_WLOCK_ASSERT(lle);					\
103 	KASSERT((lle)->lle_refcnt >= 0,				\
104 	    ("negative refcnt %d on lle %p",			\
105 	    (lle)->lle_refcnt, (lle)));				\
106 	(lle)->lle_refcnt++;					\
107 } while (0)
108 
109 #define	LLE_REMREF(lle)	do {					\
110 	LLE_WLOCK_ASSERT(lle);					\
111 	KASSERT((lle)->lle_refcnt > 0,				\
112 	    ("bogus refcnt %d on lle %p",			\
113 	    (lle)->lle_refcnt, (lle)));				\
114 	(lle)->lle_refcnt--;					\
115 } while (0)
116 
117 #define	LLE_FREE_LOCKED(lle) do {				\
118 	if ((lle)->lle_refcnt == 1)				\
119 		(lle)->lle_free(lle);				\
120 	else {							\
121 		LLE_REMREF(lle);				\
122 		LLE_WUNLOCK(lle);				\
123 	}							\
124 	/* guard against invalid refs */			\
125 	(lle) = NULL;						\
126 } while (0)
127 
128 #define	LLE_FREE(lle) do {					\
129 	LLE_WLOCK(lle);						\
130 	LLE_FREE_LOCKED(lle);					\
131 } while (0)
132 
133 
134 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
135     const struct sockaddr *l3addr);
136 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
137     const struct sockaddr *l3addr);
138 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
139 typedef void (llt_prefix_free_t)(struct lltable *,
140     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
141 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
142     struct sysctl_req *);
143 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
144 typedef int (llt_match_prefix_t)(const struct sockaddr *,
145     const struct sockaddr *, u_int, struct llentry *);
146 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
147 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
148 typedef void (llt_free_tbl_t)(struct lltable *);
149 typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
150 typedef void (llt_unlink_entry_t)(struct llentry *);
151 
152 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
153 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
154 
155 struct lltable {
156 	SLIST_ENTRY(lltable)	llt_link;
157 	int			llt_af;
158 	int			llt_hsize;
159 	struct llentries	*lle_head;
160 	struct ifnet		*llt_ifp;
161 
162 	llt_lookup_t		*llt_lookup;
163 	llt_alloc_t		*llt_alloc_entry;
164 	llt_delete_t		*llt_delete_entry;
165 	llt_prefix_free_t	*llt_prefix_free;
166 	llt_dump_entry_t	*llt_dump_entry;
167 	llt_hash_t		*llt_hash;
168 	llt_match_prefix_t	*llt_match_prefix;
169 	llt_free_entry_t	*llt_free_entry;
170 	llt_foreach_entry_t	*llt_foreach_entry;
171 	llt_link_entry_t	*llt_link_entry;
172 	llt_unlink_entry_t	*llt_unlink_entry;
173 	llt_fill_sa_entry_t	*llt_fill_sa_entry;
174 	llt_free_tbl_t		*llt_free_tbl;
175 };
176 
177 MALLOC_DECLARE(M_LLTABLE);
178 
179 /*
180  * LLentry flags
181  */
182 #define	LLE_DELETED	0x0001	/* entry must be deleted */
183 #define	LLE_STATIC	0x0002	/* entry is static */
184 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
185 #define	LLE_VALID	0x0008	/* ll_addr is valid */
186 #define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
187 #define	LLE_PUB		0x0020	/* publish entry ??? */
188 #define	LLE_LINKED	0x0040	/* linked to lookup structure */
189 /* LLE request flags */
190 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
191 
192 #define LLATBL_HASH(key, mask) \
193 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
194 
195 struct lltable *lltable_allocate_htbl(uint32_t hsize);
196 void		lltable_free(struct lltable *);
197 void		lltable_link(struct lltable *llt);
198 void		lltable_prefix_free(int, struct sockaddr *,
199 		    struct sockaddr *, u_int);
200 #if 0
201 void		lltable_drain(int);
202 #endif
203 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
204 
205 size_t		llentry_free(struct llentry *);
206 struct llentry  *llentry_alloc(struct ifnet *, struct lltable *,
207 		    struct sockaddr_storage *);
208 
209 /* helper functions */
210 size_t lltable_drop_entry_queue(struct llentry *);
211 
212 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
213     const struct sockaddr *l4addr);
214 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
215 int lltable_delete_addr(struct lltable *llt, u_int flags,
216     const struct sockaddr *l3addr);
217 void lltable_link_entry(struct lltable *llt, struct llentry *lle);
218 void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
219 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
220 struct ifnet *lltable_get_ifp(const struct lltable *llt);
221 int lltable_get_af(const struct lltable *llt);
222 
223 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
224     void *farg);
225 /*
226  * Generic link layer address lookup function.
227  */
228 static __inline struct llentry *
229 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
230 {
231 
232 	return (llt->llt_lookup(llt, flags, l3addr));
233 }
234 
235 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
236 
237 #include <sys/eventhandler.h>
238 enum {
239 	LLENTRY_RESOLVED,
240 	LLENTRY_TIMEDOUT,
241 	LLENTRY_DELETED,
242 	LLENTRY_EXPIRED,
243 };
244 typedef void (*lle_event_fn)(void *, struct llentry *, int);
245 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
246 #endif  /* _NET_IF_LLATBL_H_ */
247