xref: /freebsd/sys/net/if_llatbl.h (revision 5bf5ca772c6de2d53344a78cf461447cc322ccea)
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 
38 struct ifnet;
39 struct sysctl_req;
40 struct rt_msghdr;
41 struct rt_addrinfo;
42 struct llentry;
43 LIST_HEAD(llentries, llentry);
44 
45 #define	LLE_MAX_LINKHDR		24	/* Full IB header */
46 /*
47  * Code referencing llentry must at least hold
48  * a shared lock
49  */
50 struct llentry {
51 	LIST_ENTRY(llentry)	 lle_next;
52 	union {
53 		struct in_addr	addr4;
54 		struct in6_addr	addr6;
55 	} r_l3addr;
56 	char			r_linkdata[LLE_MAX_LINKHDR]; /* L2 data */
57 	uint8_t			r_hdrlen;	/* length for LL header */
58 	uint8_t			spare0[3];
59 	uint16_t		r_flags;	/* LLE runtime flags */
60 	uint16_t		r_skip_req;	/* feedback from fast path */
61 
62 	struct lltable		 *lle_tbl;
63 	struct llentries	 *lle_head;
64 	void			(*lle_free)(struct llentry *);
65 	struct mbuf		 *la_hold;
66 	int			 la_numheld;  /* # of packets currently held */
67 	time_t			 la_expire;
68 	uint16_t		 la_flags;
69 	uint16_t		 la_asked;
70 	uint16_t		 la_preempt;
71 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
72 	uint16_t		 ln_router;
73 	time_t			 ln_ntick;
74 	time_t			lle_remtime;	/* Real time remaining */
75 	time_t			lle_hittime;	/* Time when r_skip_req was unset */
76 	int			 lle_refcnt;
77 	char			*ll_addr;	/* link-layer address */
78 
79 	LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
80 	struct callout		lle_timer;
81 	struct rwlock		 lle_lock;
82 	struct mtx		req_mtx;
83 };
84 
85 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
86 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
87 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
88 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
89 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
90 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
91 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
92 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
93 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
94 
95 #define	LLE_REQ_INIT(lle)	mtx_init(&(lle)->req_mtx, "lle req", \
96 	NULL, MTX_DEF)
97 #define	LLE_REQ_DESTROY(lle)	mtx_destroy(&(lle)->req_mtx)
98 #define	LLE_REQ_LOCK(lle)	mtx_lock(&(lle)->req_mtx)
99 #define	LLE_REQ_UNLOCK(lle)	mtx_unlock(&(lle)->req_mtx)
100 
101 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
102 
103 #define	LLE_ADDREF(lle) do {					\
104 	LLE_WLOCK_ASSERT(lle);					\
105 	KASSERT((lle)->lle_refcnt >= 0,				\
106 	    ("negative refcnt %d on lle %p",			\
107 	    (lle)->lle_refcnt, (lle)));				\
108 	(lle)->lle_refcnt++;					\
109 } while (0)
110 
111 #define	LLE_REMREF(lle)	do {					\
112 	LLE_WLOCK_ASSERT(lle);					\
113 	KASSERT((lle)->lle_refcnt > 0,				\
114 	    ("bogus refcnt %d on lle %p",			\
115 	    (lle)->lle_refcnt, (lle)));				\
116 	(lle)->lle_refcnt--;					\
117 } while (0)
118 
119 #define	LLE_FREE_LOCKED(lle) do {				\
120 	if ((lle)->lle_refcnt == 1)				\
121 		(lle)->lle_free(lle);				\
122 	else {							\
123 		LLE_REMREF(lle);				\
124 		LLE_WUNLOCK(lle);				\
125 	}							\
126 	/* guard against invalid refs */			\
127 	(lle) = NULL;						\
128 } while (0)
129 
130 #define	LLE_FREE(lle) do {					\
131 	LLE_WLOCK(lle);						\
132 	LLE_FREE_LOCKED(lle);					\
133 } while (0)
134 
135 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
136     const struct sockaddr *l3addr);
137 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
138     const struct sockaddr *l3addr);
139 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
140 typedef void (llt_prefix_free_t)(struct lltable *,
141     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
142 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
143     struct sysctl_req *);
144 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
145 typedef int (llt_match_prefix_t)(const struct sockaddr *,
146     const struct sockaddr *, u_int, struct llentry *);
147 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
148 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
149 typedef void (llt_free_tbl_t)(struct lltable *);
150 typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
151 typedef void (llt_unlink_entry_t)(struct llentry *);
152 
153 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
154 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
155 
156 struct lltable {
157 	SLIST_ENTRY(lltable)	llt_link;
158 	int			llt_af;
159 	int			llt_hsize;
160 	struct llentries	*lle_head;
161 	struct ifnet		*llt_ifp;
162 
163 	llt_lookup_t		*llt_lookup;
164 	llt_alloc_t		*llt_alloc_entry;
165 	llt_delete_t		*llt_delete_entry;
166 	llt_prefix_free_t	*llt_prefix_free;
167 	llt_dump_entry_t	*llt_dump_entry;
168 	llt_hash_t		*llt_hash;
169 	llt_match_prefix_t	*llt_match_prefix;
170 	llt_free_entry_t	*llt_free_entry;
171 	llt_foreach_entry_t	*llt_foreach_entry;
172 	llt_link_entry_t	*llt_link_entry;
173 	llt_unlink_entry_t	*llt_unlink_entry;
174 	llt_fill_sa_entry_t	*llt_fill_sa_entry;
175 	llt_free_tbl_t		*llt_free_tbl;
176 };
177 
178 MALLOC_DECLARE(M_LLTABLE);
179 
180 /*
181  * LLentry flags
182  */
183 #define	LLE_DELETED	0x0001	/* entry must be deleted */
184 #define	LLE_STATIC	0x0002	/* entry is static */
185 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
186 #define	LLE_VALID	0x0008	/* ll_addr is valid */
187 #define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
188 #define	LLE_PUB		0x0020	/* publish entry ??? */
189 #define	LLE_LINKED	0x0040	/* linked to lookup structure */
190 /* LLE request flags */
191 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
192 #define	LLE_UNLOCKED	0x4000	/* return lle unlocked */
193 #define	LLE_ADDRONLY	0x4000	/* return lladdr instead of full header */
194 #define	LLE_CREATE	0x8000	/* hint to avoid lle lookup */
195 
196 /* LLE flags used by fastpath code */
197 #define	RLLE_VALID	0x0001		/* entry is valid */
198 #define	RLLE_IFADDR	LLE_IFADDR	/* entry is ifaddr */
199 
200 #define LLATBL_HASH(key, mask) \
201 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
202 
203 struct lltable *lltable_allocate_htbl(uint32_t hsize);
204 void		lltable_free(struct lltable *);
205 void		lltable_link(struct lltable *llt);
206 void		lltable_prefix_free(int, struct sockaddr *,
207 		    struct sockaddr *, u_int);
208 #if 0
209 void		lltable_drain(int);
210 #endif
211 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
212 
213 size_t		llentry_free(struct llentry *);
214 struct llentry  *llentry_alloc(struct ifnet *, struct lltable *,
215 		    struct sockaddr_storage *);
216 
217 /* helper functions */
218 size_t lltable_drop_entry_queue(struct llentry *);
219 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
220     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
221 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
222     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
223 
224 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
225     char *buf, size_t *bufsize, int *lladdr_off);
226 void lltable_update_ifaddr(struct lltable *llt);
227 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
228     const struct sockaddr *l4addr);
229 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
230 int lltable_delete_addr(struct lltable *llt, u_int flags,
231     const struct sockaddr *l3addr);
232 void lltable_link_entry(struct lltable *llt, struct llentry *lle);
233 void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
234 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
235 struct ifnet *lltable_get_ifp(const struct lltable *llt);
236 int lltable_get_af(const struct lltable *llt);
237 
238 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
239     void *farg);
240 /*
241  * Generic link layer address lookup function.
242  */
243 static __inline struct llentry *
244 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
245 {
246 
247 	return (llt->llt_lookup(llt, flags, l3addr));
248 }
249 
250 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
251 
252 #include <sys/eventhandler.h>
253 enum {
254 	LLENTRY_RESOLVED,
255 	LLENTRY_TIMEDOUT,
256 	LLENTRY_DELETED,
257 	LLENTRY_EXPIRED,
258 };
259 typedef void (*lle_event_fn)(void *, struct llentry *, int);
260 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
261 #endif  /* _NET_IF_LLATBL_H_ */
262