xref: /freebsd/sys/net/if_llatbl.h (revision 86c71e97d19f8b82b8ab79a56b20998ada7ee868)
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/_eventhandler.h>
36 #include <sys/_rwlock.h>
37 #include <netinet/in.h>
38 #include <sys/epoch.h>
39 #include <sys/ck.h>
40 
41 struct ifnet;
42 struct sysctl_req;
43 struct rt_msghdr;
44 struct rt_addrinfo;
45 struct llentry;
46 CK_LIST_HEAD(llentries, llentry);
47 
48 #define	LLE_MAX_LINKHDR		24	/* Full IB header */
49 /*
50  * Code referencing llentry must at least hold
51  * a shared lock
52  */
53 struct llentry {
54 	CK_LIST_ENTRY(llentry)	 lle_next;
55 	union {
56 		struct in_addr	addr4;
57 		struct in6_addr	addr6;
58 	} r_l3addr;
59 	char			r_linkdata[LLE_MAX_LINKHDR]; /* L2 data */
60 	uint8_t			r_hdrlen;	/* length for LL header */
61 	uint8_t			spare0[3];
62 	uint16_t		r_flags;	/* LLE runtime flags */
63 	uint16_t		r_skip_req;	/* feedback from fast path */
64 
65 	struct lltable		 *lle_tbl;
66 	struct llentries	 *lle_head;
67 	void			(*lle_free)(struct llentry *);
68 	struct mbuf		 *la_hold;
69 	int			 la_numheld;  /* # of packets currently held */
70 	time_t			 la_expire;
71 	uint16_t		 la_flags;
72 	uint16_t		 la_asked;
73 	uint16_t		 la_preempt;
74 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
75 	uint16_t		 ln_router;
76 	time_t			 ln_ntick;
77 	time_t			lle_remtime;	/* Real time remaining */
78 	time_t			lle_hittime;	/* Time when r_skip_req was unset */
79 	int			 lle_refcnt;
80 	char			*ll_addr;	/* link-layer address */
81 
82 	CK_LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
83 	struct callout		lle_timer;
84 	struct rwlock		 lle_lock;
85 	struct mtx		req_mtx;
86 	struct epoch_context lle_epoch_ctx;
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_REQ_INIT(lle)	mtx_init(&(lle)->req_mtx, "lle req", \
100 	NULL, MTX_DEF)
101 #define	LLE_REQ_DESTROY(lle)	mtx_destroy(&(lle)->req_mtx)
102 #define	LLE_REQ_LOCK(lle)	mtx_lock(&(lle)->req_mtx)
103 #define	LLE_REQ_UNLOCK(lle)	mtx_unlock(&(lle)->req_mtx)
104 
105 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
106 
107 #define	LLE_ADDREF(lle) do {					\
108 	LLE_WLOCK_ASSERT(lle);					\
109 	KASSERT((lle)->lle_refcnt >= 0,				\
110 	    ("negative refcnt %d on lle %p",			\
111 	    (lle)->lle_refcnt, (lle)));				\
112 	(lle)->lle_refcnt++;					\
113 } while (0)
114 
115 #define	LLE_REMREF(lle)	do {					\
116 	LLE_WLOCK_ASSERT(lle);					\
117 	KASSERT((lle)->lle_refcnt > 0,				\
118 	    ("bogus refcnt %d on lle %p",			\
119 	    (lle)->lle_refcnt, (lle)));				\
120 	(lle)->lle_refcnt--;					\
121 } while (0)
122 
123 #define	LLE_FREE_LOCKED(lle) do {				\
124 	if ((lle)->lle_refcnt == 1)				\
125 		(lle)->lle_free(lle);				\
126 	else {							\
127 		LLE_REMREF(lle);				\
128 		LLE_WUNLOCK(lle);				\
129 	}							\
130 	/* guard against invalid refs */			\
131 	(lle) = NULL;						\
132 } while (0)
133 
134 #define	LLE_FREE(lle) do {					\
135 	LLE_WLOCK(lle);						\
136 	LLE_FREE_LOCKED(lle);					\
137 } while (0)
138 
139 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
140     const struct sockaddr *l3addr);
141 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
142     const struct sockaddr *l3addr);
143 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
144 typedef void (llt_prefix_free_t)(struct lltable *,
145     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
146 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
147     struct sysctl_req *);
148 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
149 typedef int (llt_match_prefix_t)(const struct sockaddr *,
150     const struct sockaddr *, u_int, struct llentry *);
151 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
152 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
153 typedef void (llt_free_tbl_t)(struct lltable *);
154 typedef int (llt_link_entry_t)(struct lltable *, struct llentry *);
155 typedef int (llt_unlink_entry_t)(struct llentry *);
156 typedef void (llt_mark_used_t)(struct llentry *);
157 
158 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
159 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
160 
161 struct lltable {
162 	SLIST_ENTRY(lltable)	llt_link;
163 	int			llt_af;
164 	int			llt_hsize;
165 	int			llt_entries;
166 	int			llt_maxentries;
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 
186 MALLOC_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 
211 struct lltable *lltable_allocate_htbl(uint32_t hsize);
212 void		lltable_free(struct lltable *);
213 void		lltable_link(struct lltable *llt);
214 void		lltable_prefix_free(int, struct sockaddr *,
215 		    struct sockaddr *, u_int);
216 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
217 
218 size_t		llentry_free(struct llentry *);
219 
220 /* helper functions */
221 size_t lltable_drop_entry_queue(struct llentry *);
222 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
223     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
224 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
225     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
226 
227 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
228     char *buf, size_t *bufsize, int *lladdr_off);
229 void lltable_update_ifaddr(struct lltable *llt);
230 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
231     const struct sockaddr *l4addr);
232 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
233 int lltable_delete_addr(struct lltable *llt, u_int flags,
234     const struct sockaddr *l3addr);
235 int lltable_link_entry(struct lltable *llt, struct llentry *lle);
236 int lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
237 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
238 struct ifnet *lltable_get_ifp(const struct lltable *llt);
239 int lltable_get_af(const struct lltable *llt);
240 
241 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
242     void *farg);
243 /*
244  * Generic link layer address lookup function.
245  */
246 static __inline struct llentry *
247 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
248 {
249 
250 	return (llt->llt_lookup(llt, flags, l3addr));
251 }
252 
253 void llentry_request_feedback(struct llentry *lle);
254 void llentry_mark_used(struct llentry *lle);
255 time_t llentry_get_hittime(struct llentry *lle);
256 
257 /*
258  * Notify the LLE code that the entry was used by datapath.
259  */
260 static __inline void
261 llentry_provide_feedback(struct llentry *lle)
262 {
263 
264 	if (__predict_true(lle->r_skip_req == 0))
265 		return;
266 	llentry_mark_used(lle);
267 }
268 
269 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
270 
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