xref: /freebsd/sys/net/if_llatbl.h (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
5  * Copyright (c) 2004-2008 Qing Li. All rights reserved.
6  * Copyright (c) 2008 Kip Macy. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY AUTHOR 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 AUTHOR 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 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #ifndef	_NET_IF_LLATBL_H_
33 #define	_NET_IF_LLATBL_H_
34 
35 #include <sys/_rwlock.h>
36 #include <netinet/in.h>
37 #include <sys/epoch.h>
38 #include <sys/ck.h>
39 
40 struct ifnet;
41 struct sysctl_req;
42 struct rt_msghdr;
43 struct rt_addrinfo;
44 struct llentry;
45 CK_LIST_HEAD(llentries, llentry);
46 
47 #define	LLE_MAX_LINKHDR		24	/* Full IB header */
48 /*
49  * Code referencing llentry must at least hold
50  * a shared lock
51  */
52 struct llentry {
53 	CK_LIST_ENTRY(llentry)	 lle_next;
54 	union {
55 		struct in_addr	addr4;
56 		struct in6_addr	addr6;
57 	} r_l3addr;
58 	char			r_linkdata[LLE_MAX_LINKHDR]; /* L2 data */
59 	uint8_t			r_hdrlen;	/* length for LL header */
60 	uint8_t			spare0[3];
61 	uint16_t		r_flags;	/* LLE runtime flags */
62 	uint16_t		r_skip_req;	/* feedback from fast path */
63 
64 	struct lltable		 *lle_tbl;
65 	struct llentries	 *lle_head;
66 	void			(*lle_free)(struct llentry *);
67 	struct mbuf		 *la_hold;
68 	int			 la_numheld;  /* # of packets currently held */
69 	time_t			 la_expire;
70 	uint16_t		 la_flags;
71 	uint16_t		 la_asked;
72 	uint16_t		 la_preempt;
73 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
74 	uint16_t		 ln_router;
75 	time_t			 ln_ntick;
76 	time_t			lle_remtime;	/* Real time remaining */
77 	time_t			lle_hittime;	/* Time when r_skip_req was unset */
78 	int			 lle_refcnt;
79 	char			*ll_addr;	/* link-layer address */
80 
81 	CK_LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
82 	struct callout		lle_timer;
83 	struct rwlock		 lle_lock;
84 	struct mtx		req_mtx;
85 	struct epoch_context lle_epoch_ctx;
86 };
87 
88 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
89 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
90 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
91 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
92 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
93 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
94 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
95 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
96 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
97 
98 #define	LLE_REQ_INIT(lle)	mtx_init(&(lle)->req_mtx, "lle req", \
99 	NULL, MTX_DEF)
100 #define	LLE_REQ_DESTROY(lle)	mtx_destroy(&(lle)->req_mtx)
101 #define	LLE_REQ_LOCK(lle)	mtx_lock(&(lle)->req_mtx)
102 #define	LLE_REQ_UNLOCK(lle)	mtx_unlock(&(lle)->req_mtx)
103 
104 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
105 
106 #define	LLE_ADDREF(lle) do {					\
107 	LLE_WLOCK_ASSERT(lle);					\
108 	KASSERT((lle)->lle_refcnt >= 0,				\
109 	    ("negative refcnt %d on lle %p",			\
110 	    (lle)->lle_refcnt, (lle)));				\
111 	(lle)->lle_refcnt++;					\
112 } while (0)
113 
114 #define	LLE_REMREF(lle)	do {					\
115 	LLE_WLOCK_ASSERT(lle);					\
116 	KASSERT((lle)->lle_refcnt > 0,				\
117 	    ("bogus refcnt %d on lle %p",			\
118 	    (lle)->lle_refcnt, (lle)));				\
119 	(lle)->lle_refcnt--;					\
120 } while (0)
121 
122 #define	LLE_FREE_LOCKED(lle) do {				\
123 	if ((lle)->lle_refcnt == 1)				\
124 		(lle)->lle_free(lle);				\
125 	else {							\
126 		LLE_REMREF(lle);				\
127 		LLE_WUNLOCK(lle);				\
128 	}							\
129 	/* guard against invalid refs */			\
130 	(lle) = NULL;						\
131 } while (0)
132 
133 #define	LLE_FREE(lle) do {					\
134 	LLE_WLOCK(lle);						\
135 	LLE_FREE_LOCKED(lle);					\
136 } while (0)
137 
138 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
139     const struct sockaddr *l3addr);
140 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
141     const struct sockaddr *l3addr);
142 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
143 typedef void (llt_prefix_free_t)(struct lltable *,
144     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
145 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
146     struct sysctl_req *);
147 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
148 typedef int (llt_match_prefix_t)(const struct sockaddr *,
149     const struct sockaddr *, u_int, struct llentry *);
150 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
151 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
152 typedef void (llt_free_tbl_t)(struct lltable *);
153 typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
154 typedef void (llt_unlink_entry_t)(struct llentry *);
155 typedef void (llt_mark_used_t)(struct llentry *);
156 
157 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
158 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
159 
160 struct lltable {
161 	SLIST_ENTRY(lltable)	llt_link;
162 	int			llt_af;
163 	int			llt_hsize;
164 	struct llentries	*lle_head;
165 	struct ifnet		*llt_ifp;
166 
167 	llt_lookup_t		*llt_lookup;
168 	llt_alloc_t		*llt_alloc_entry;
169 	llt_delete_t		*llt_delete_entry;
170 	llt_prefix_free_t	*llt_prefix_free;
171 	llt_dump_entry_t	*llt_dump_entry;
172 	llt_hash_t		*llt_hash;
173 	llt_match_prefix_t	*llt_match_prefix;
174 	llt_free_entry_t	*llt_free_entry;
175 	llt_foreach_entry_t	*llt_foreach_entry;
176 	llt_link_entry_t	*llt_link_entry;
177 	llt_unlink_entry_t	*llt_unlink_entry;
178 	llt_fill_sa_entry_t	*llt_fill_sa_entry;
179 	llt_free_tbl_t		*llt_free_tbl;
180 	llt_mark_used_t		*llt_mark_used;
181 };
182 
183 MALLOC_DECLARE(M_LLTABLE);
184 
185 /*
186  * LLentry flags
187  */
188 #define	LLE_DELETED	0x0001	/* entry must be deleted */
189 #define	LLE_STATIC	0x0002	/* entry is static */
190 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
191 #define	LLE_VALID	0x0008	/* ll_addr is valid */
192 #define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
193 #define	LLE_PUB		0x0020	/* publish entry ??? */
194 #define	LLE_LINKED	0x0040	/* linked to lookup structure */
195 /* LLE request flags */
196 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
197 #define	LLE_UNLOCKED	0x4000	/* return lle unlocked */
198 #define	LLE_ADDRONLY	0x4000	/* return lladdr instead of full header */
199 #define	LLE_CREATE	0x8000	/* hint to avoid lle lookup */
200 
201 /* LLE flags used by fastpath code */
202 #define	RLLE_VALID	0x0001		/* entry is valid */
203 #define	RLLE_IFADDR	LLE_IFADDR	/* entry is ifaddr */
204 
205 #define LLATBL_HASH(key, mask) \
206 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
207 
208 struct lltable *lltable_allocate_htbl(uint32_t hsize);
209 void		lltable_free(struct lltable *);
210 void		lltable_link(struct lltable *llt);
211 void		lltable_prefix_free(int, struct sockaddr *,
212 		    struct sockaddr *, u_int);
213 #if 0
214 void		lltable_drain(int);
215 #endif
216 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
217 
218 size_t		llentry_free(struct llentry *);
219 struct llentry  *llentry_alloc(struct ifnet *, struct lltable *,
220 		    struct sockaddr_storage *);
221 
222 /* helper functions */
223 size_t lltable_drop_entry_queue(struct llentry *);
224 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
225     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
226 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
227     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
228 
229 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
230     char *buf, size_t *bufsize, int *lladdr_off);
231 void lltable_update_ifaddr(struct lltable *llt);
232 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
233     const struct sockaddr *l4addr);
234 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
235 int lltable_delete_addr(struct lltable *llt, u_int flags,
236     const struct sockaddr *l3addr);
237 void lltable_link_entry(struct lltable *llt, struct llentry *lle);
238 void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
239 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
240 struct ifnet *lltable_get_ifp(const struct lltable *llt);
241 int lltable_get_af(const struct lltable *llt);
242 
243 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
244     void *farg);
245 /*
246  * Generic link layer address lookup function.
247  */
248 static __inline struct llentry *
249 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
250 {
251 
252 	return (llt->llt_lookup(llt, flags, l3addr));
253 }
254 
255 /*
256  * Notify the LLE code that the entry was used by datapath.
257  */
258 static __inline void
259 llentry_mark_used(struct llentry *lle)
260 {
261 
262 	if (lle->r_skip_req == 0)
263 		return;
264 	if ((lle->r_flags & RLLE_VALID) != 0)
265 		lle->lle_tbl->llt_mark_used(lle);
266 }
267 
268 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
269 
270 #include <sys/eventhandler.h>
271 enum {
272 	LLENTRY_RESOLVED,
273 	LLENTRY_TIMEDOUT,
274 	LLENTRY_DELETED,
275 	LLENTRY_EXPIRED,
276 };
277 typedef void (*lle_event_fn)(void *, struct llentry *, int);
278 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
279 #endif  /* _NET_IF_LLATBL_H_ */
280