xref: /freebsd/sys/net/if_llatbl.h (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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 struct llentry;
41 LIST_HEAD(llentries, llentry);
42 
43 #define	LLE_MAX_LINKHDR		24	/* Full IB header */
44 /*
45  * Code referencing llentry must at least hold
46  * a shared lock
47  */
48 struct llentry {
49 	LIST_ENTRY(llentry)	 lle_next;
50 	union {
51 		struct in_addr	addr4;
52 		struct in6_addr	addr6;
53 	} r_l3addr;
54 	char			r_linkdata[LLE_MAX_LINKHDR]; /* L2 data */
55 	uint8_t			r_hdrlen;	/* length for LL header */
56 	uint8_t			spare0[3];
57 	uint16_t		r_flags;	/* LLE runtime flags */
58 	uint16_t		r_skip_req;	/* feedback from fast path */
59 
60 	struct lltable		 *lle_tbl;
61 	struct llentries	 *lle_head;
62 	void			(*lle_free)(struct llentry *);
63 	struct mbuf		 *la_hold;
64 	int			 la_numheld;  /* # of packets currently held */
65 	time_t			 la_expire;
66 	uint16_t		 la_flags;
67 	uint16_t		 la_asked;
68 	uint16_t		 la_preempt;
69 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
70 	uint16_t		 ln_router;
71 	time_t			 ln_ntick;
72 	time_t			lle_remtime;	/* Real time remaining */
73 	time_t			lle_hittime;	/* Time when r_skip_req was unset */
74 	int			 lle_refcnt;
75 	char			*ll_addr;	/* link-layer address */
76 
77 	LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
78 	struct callout		lle_timer;
79 	struct rwlock		 lle_lock;
80 	struct mtx		req_mtx;
81 };
82 
83 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
84 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
85 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
86 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
87 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
88 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
89 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
90 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
91 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
92 
93 #define	LLE_REQ_INIT(lle)	mtx_init(&(lle)->req_mtx, "lle req", \
94 	NULL, MTX_DEF)
95 #define	LLE_REQ_DESTROY(lle)	mtx_destroy(&(lle)->req_mtx)
96 #define	LLE_REQ_LOCK(lle)	mtx_lock(&(lle)->req_mtx)
97 #define	LLE_REQ_UNLOCK(lle)	mtx_unlock(&(lle)->req_mtx)
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 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
134     const struct sockaddr *l3addr);
135 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
136     const struct sockaddr *l3addr);
137 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
138 typedef void (llt_prefix_free_t)(struct lltable *,
139     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
140 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
141     struct sysctl_req *);
142 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
143 typedef int (llt_match_prefix_t)(const struct sockaddr *,
144     const struct sockaddr *, u_int, struct llentry *);
145 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
146 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
147 typedef void (llt_free_tbl_t)(struct lltable *);
148 typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
149 typedef void (llt_unlink_entry_t)(struct llentry *);
150 
151 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
152 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
153 
154 struct lltable {
155 	SLIST_ENTRY(lltable)	llt_link;
156 	int			llt_af;
157 	int			llt_hsize;
158 	struct llentries	*lle_head;
159 	struct ifnet		*llt_ifp;
160 
161 	llt_lookup_t		*llt_lookup;
162 	llt_alloc_t		*llt_alloc_entry;
163 	llt_delete_t		*llt_delete_entry;
164 	llt_prefix_free_t	*llt_prefix_free;
165 	llt_dump_entry_t	*llt_dump_entry;
166 	llt_hash_t		*llt_hash;
167 	llt_match_prefix_t	*llt_match_prefix;
168 	llt_free_entry_t	*llt_free_entry;
169 	llt_foreach_entry_t	*llt_foreach_entry;
170 	llt_link_entry_t	*llt_link_entry;
171 	llt_unlink_entry_t	*llt_unlink_entry;
172 	llt_fill_sa_entry_t	*llt_fill_sa_entry;
173 	llt_free_tbl_t		*llt_free_tbl;
174 };
175 
176 MALLOC_DECLARE(M_LLTABLE);
177 
178 /*
179  * LLentry flags
180  */
181 #define	LLE_DELETED	0x0001	/* entry must be deleted */
182 #define	LLE_STATIC	0x0002	/* entry is static */
183 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
184 #define	LLE_VALID	0x0008	/* ll_addr is valid */
185 #define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
186 #define	LLE_PUB		0x0020	/* publish entry ??? */
187 #define	LLE_LINKED	0x0040	/* linked to lookup structure */
188 /* LLE request flags */
189 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
190 #define	LLE_UNLOCKED	0x4000	/* return lle unlocked */
191 #define	LLE_ADDRONLY	0x4000	/* return lladdr instead of full header */
192 #define	LLE_CREATE	0x8000	/* hint to avoid lle lookup */
193 
194 /* LLE flags used by fastpath code */
195 #define	RLLE_VALID	0x0001		/* entry is valid */
196 #define	RLLE_IFADDR	LLE_IFADDR	/* entry is ifaddr */
197 
198 #define LLATBL_HASH(key, mask) \
199 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
200 
201 struct lltable *lltable_allocate_htbl(uint32_t hsize);
202 void		lltable_free(struct lltable *);
203 void		lltable_link(struct lltable *llt);
204 void		lltable_prefix_free(int, struct sockaddr *,
205 		    struct sockaddr *, u_int);
206 #if 0
207 void		lltable_drain(int);
208 #endif
209 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
210 
211 size_t		llentry_free(struct llentry *);
212 struct llentry  *llentry_alloc(struct ifnet *, struct lltable *,
213 		    struct sockaddr_storage *);
214 
215 /* helper functions */
216 size_t lltable_drop_entry_queue(struct llentry *);
217 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
218     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
219 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
220     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
221 
222 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
223     char *buf, size_t *bufsize, int *lladdr_off);
224 void lltable_update_ifaddr(struct lltable *llt);
225 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
226     const struct sockaddr *l4addr);
227 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
228 int lltable_delete_addr(struct lltable *llt, u_int flags,
229     const struct sockaddr *l3addr);
230 void lltable_link_entry(struct lltable *llt, struct llentry *lle);
231 void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
232 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
233 struct ifnet *lltable_get_ifp(const struct lltable *llt);
234 int lltable_get_af(const struct lltable *llt);
235 
236 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
237     void *farg);
238 /*
239  * Generic link layer address lookup function.
240  */
241 static __inline struct llentry *
242 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
243 {
244 
245 	return (llt->llt_lookup(llt, flags, l3addr));
246 }
247 
248 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
249 
250 #include <sys/eventhandler.h>
251 enum {
252 	LLENTRY_RESOLVED,
253 	LLENTRY_TIMEDOUT,
254 	LLENTRY_DELETED,
255 	LLENTRY_EXPIRED,
256 };
257 typedef void (*lle_event_fn)(void *, struct llentry *, int);
258 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
259 #endif  /* _NET_IF_LLATBL_H_ */
260