xref: /freebsd/sys/net/if_llatbl.h (revision 15c433351f54e7cd5bec8d36c8e89e6a7fa55b26)
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 #define	LLE_MAX_LINKHDR		24	/* Full IB header */
52 /*
53  * Code referencing llentry must at least hold
54  * a shared lock
55  */
56 struct 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 
141 
142 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
143     const struct sockaddr *l3addr);
144 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
145     const struct sockaddr *l3addr);
146 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
147 typedef void (llt_prefix_free_t)(struct lltable *,
148     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
149 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
150     struct sysctl_req *);
151 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
152 typedef int (llt_match_prefix_t)(const struct sockaddr *,
153     const struct sockaddr *, u_int, struct llentry *);
154 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
155 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
156 typedef void (llt_free_tbl_t)(struct lltable *);
157 typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
158 typedef void (llt_unlink_entry_t)(struct llentry *);
159 
160 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
161 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
162 
163 struct 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 };
184 
185 MALLOC_DECLARE(M_LLTABLE);
186 
187 /*
188  * LLentry flags
189  */
190 #define	LLE_DELETED	0x0001	/* entry must be deleted */
191 #define	LLE_STATIC	0x0002	/* entry is static */
192 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
193 #define	LLE_VALID	0x0008	/* ll_addr is valid */
194 #define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
195 #define	LLE_PUB		0x0020	/* publish entry ??? */
196 #define	LLE_LINKED	0x0040	/* linked to lookup structure */
197 /* LLE request flags */
198 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
199 #define	LLE_UNLOCKED	0x4000	/* return lle unlocked */
200 #define	LLE_ADDRONLY	0x4000	/* return lladdr instead of full header */
201 #define	LLE_CREATE	0x8000	/* hint to avoid lle lookup */
202 
203 /* LLE flags used by fastpath code */
204 #define	RLLE_VALID	0x0001		/* entry is valid */
205 #define	RLLE_IFADDR	LLE_IFADDR	/* entry is ifaddr */
206 
207 #define LLATBL_HASH(key, mask) \
208 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
209 
210 struct lltable *lltable_allocate_htbl(uint32_t hsize);
211 void		lltable_free(struct lltable *);
212 void		lltable_link(struct lltable *llt);
213 void		lltable_prefix_free(int, struct sockaddr *,
214 		    struct sockaddr *, u_int);
215 #if 0
216 void		lltable_drain(int);
217 #endif
218 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
219 
220 size_t		llentry_free(struct llentry *);
221 struct llentry  *llentry_alloc(struct ifnet *, struct lltable *,
222 		    struct sockaddr_storage *);
223 
224 /* helper functions */
225 size_t lltable_drop_entry_queue(struct llentry *);
226 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
227     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
228 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
229     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
230 
231 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
232     char *buf, size_t *bufsize, int *lladdr_off);
233 void lltable_update_ifaddr(struct lltable *llt);
234 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
235     const struct sockaddr *l4addr);
236 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
237 int lltable_delete_addr(struct lltable *llt, u_int flags,
238     const struct sockaddr *l3addr);
239 void lltable_link_entry(struct lltable *llt, struct llentry *lle);
240 void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
241 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
242 struct ifnet *lltable_get_ifp(const struct lltable *llt);
243 int lltable_get_af(const struct lltable *llt);
244 
245 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
246     void *farg);
247 /*
248  * Generic link layer address lookup function.
249  */
250 static __inline struct llentry *
251 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
252 {
253 
254 	return (llt->llt_lookup(llt, flags, l3addr));
255 }
256 
257 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
258 
259 #include <sys/eventhandler.h>
260 enum {
261 	LLENTRY_RESOLVED,
262 	LLENTRY_TIMEDOUT,
263 	LLENTRY_DELETED,
264 	LLENTRY_EXPIRED,
265 };
266 typedef void (*lle_event_fn)(void *, struct llentry *, int);
267 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
268 #endif  /* _NET_IF_LLATBL_H_ */
269