xref: /freebsd/sys/net/if_llatbl.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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			r_family;	/* Upper layer proto family */
62 	uint8_t			spare0[2];
63 	uint16_t		r_flags;	/* LLE runtime flags */
64 	uint16_t		r_skip_req;	/* feedback from fast path */
65 
66 	struct lltable		 *lle_tbl;
67 	struct llentries	 *lle_head;
68 	void			(*lle_free)(struct llentry *);
69 	struct mbuf		 *la_hold;
70 	int			 la_numheld;  /* # of packets currently held */
71 	time_t			 la_expire;
72 	uint16_t		 la_flags;
73 	uint16_t		 la_asked;
74 	uint16_t		 la_preempt;
75 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
76 	uint16_t		 ln_router;
77 	time_t			 ln_ntick;
78 	time_t			lle_remtime;	/* Real time remaining */
79 	time_t			lle_hittime;	/* Time when r_skip_req was unset */
80 	int			 lle_refcnt;
81 	char			*ll_addr;	/* link-layer address */
82 	CK_SLIST_HEAD(llentry_children_head,llentry)	lle_children;	/* child encaps */
83 	CK_SLIST_ENTRY(llentry)	lle_child_next;	/* child encaps */
84 	struct llentry		*lle_parent;	/* parent for a child */
85 
86 	CK_LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
87 	struct callout		lle_timer;
88 	struct rwlock		 lle_lock;
89 	struct mtx		req_mtx;
90 	struct epoch_context lle_epoch_ctx;
91 };
92 
93 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
94 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
95 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
96 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
97 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
98 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
99 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
100 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
101 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
102 
103 #define	LLE_REQ_INIT(lle)	mtx_init(&(lle)->req_mtx, "lle req", \
104 	NULL, MTX_DEF)
105 #define	LLE_REQ_DESTROY(lle)	mtx_destroy(&(lle)->req_mtx)
106 #define	LLE_REQ_LOCK(lle)	mtx_lock(&(lle)->req_mtx)
107 #define	LLE_REQ_UNLOCK(lle)	mtx_unlock(&(lle)->req_mtx)
108 
109 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
110 
111 #define	LLE_SF(_fam, _flags)	(((_flags) & 0xFFFF) | ((_fam) << 16))
112 
113 #define	LLE_ADDREF(lle) do {					\
114 	LLE_WLOCK_ASSERT(lle);					\
115 	KASSERT((lle)->lle_refcnt >= 0,				\
116 	    ("negative refcnt %d on lle %p",			\
117 	    (lle)->lle_refcnt, (lle)));				\
118 	(lle)->lle_refcnt++;					\
119 } while (0)
120 
121 #define	LLE_REMREF(lle)	do {					\
122 	LLE_WLOCK_ASSERT(lle);					\
123 	KASSERT((lle)->lle_refcnt > 0,				\
124 	    ("bogus refcnt %d on lle %p",			\
125 	    (lle)->lle_refcnt, (lle)));				\
126 	(lle)->lle_refcnt--;					\
127 } while (0)
128 
129 #define	LLE_FREE_LOCKED(lle) do {				\
130 	if ((lle)->lle_refcnt == 1)				\
131 		(lle)->lle_free(lle);				\
132 	else {							\
133 		LLE_REMREF(lle);				\
134 		LLE_WUNLOCK(lle);				\
135 	}							\
136 	/* guard against invalid refs */			\
137 	(lle) = NULL;						\
138 } while (0)
139 
140 #define	LLE_FREE(lle) do {					\
141 	LLE_WLOCK(lle);						\
142 	LLE_FREE_LOCKED(lle);					\
143 } while (0)
144 
145 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
146     const struct sockaddr *l3addr);
147 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
148     const struct sockaddr *l3addr);
149 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
150 typedef void (llt_prefix_free_t)(struct lltable *,
151     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
152 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
153     struct sysctl_req *);
154 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
155 typedef int (llt_match_prefix_t)(const struct sockaddr *,
156     const struct sockaddr *, u_int, struct llentry *);
157 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
158 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
159 typedef void (llt_free_tbl_t)(struct lltable *);
160 typedef int (llt_link_entry_t)(struct lltable *, struct llentry *);
161 typedef int (llt_unlink_entry_t)(struct llentry *);
162 typedef void (llt_mark_used_t)(struct llentry *);
163 typedef void (llt_post_resolved_t)(struct lltable *, struct llentry *);
164 
165 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
166 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
167 typedef bool (llt_match_cb_t)(struct lltable *, struct llentry *, void *);
168 
169 struct lltable {
170 	SLIST_ENTRY(lltable)	llt_link;
171 	sa_family_t		llt_af;
172 	uint8_t			llt_flags;
173 	uint8_t			llt_spare[2];
174 	int			llt_hsize;
175 	int			llt_entries;
176 	int			llt_maxentries;
177 	struct llentries	*lle_head;
178 	struct ifnet		*llt_ifp;
179 
180 	llt_lookup_t		*llt_lookup;
181 	llt_alloc_t		*llt_alloc_entry;
182 	llt_delete_t		*llt_delete_entry;
183 	llt_prefix_free_t	*llt_prefix_free;
184 	llt_dump_entry_t	*llt_dump_entry;
185 	llt_hash_t		*llt_hash;
186 	llt_match_prefix_t	*llt_match_prefix;
187 	llt_free_entry_t	*llt_free_entry;
188 	llt_foreach_entry_t	*llt_foreach_entry;
189 	llt_link_entry_t	*llt_link_entry;
190 	llt_unlink_entry_t	*llt_unlink_entry;
191 	llt_fill_sa_entry_t	*llt_fill_sa_entry;
192 	llt_free_tbl_t		*llt_free_tbl;
193 	llt_mark_used_t		*llt_mark_used;
194 	llt_post_resolved_t	*llt_post_resolved;
195 };
196 
197 MALLOC_DECLARE(M_LLTABLE);
198 
199 /*
200  * LLtable flags
201  */
202 #define	LLT_ADDEDPROXY	0x01	/* added a proxy llentry */
203 
204 /*
205  * LLentry flags
206  */
207 #define	LLE_DELETED	0x0001	/* entry must be deleted */
208 #define	LLE_STATIC	0x0002	/* entry is static */
209 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
210 #define	LLE_VALID	0x0008	/* ll_addr is valid */
211 #define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
212 #define	LLE_PUB		0x0020	/* publish entry ??? */
213 #define	LLE_LINKED	0x0040	/* linked to lookup structure */
214 #define	LLE_CHILD	0x0080	/* Child LLE storing different AF encap */
215 /* LLE request flags */
216 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
217 #define	LLE_UNLOCKED	0x4000	/* return lle unlocked */
218 #define	LLE_ADDRONLY	0x4000	/* return lladdr instead of full header */
219 #define	LLE_CREATE	0x8000	/* hint to avoid lle lookup */
220 
221 /* LLE flags used by fastpath code */
222 #define	RLLE_VALID	0x0001		/* entry is valid */
223 #define	RLLE_IFADDR	LLE_IFADDR	/* entry is ifaddr */
224 
225 #define LLATBL_HASH(key, mask) \
226 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
227 
228 struct lltable *lltable_allocate_htbl(uint32_t hsize);
229 void		lltable_free(struct lltable *);
230 void		lltable_link(struct lltable *llt);
231 void		lltable_prefix_free(int, struct sockaddr *,
232 		    struct sockaddr *, u_int);
233 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
234 size_t		lltable_append_entry_queue(struct llentry *,
235 		    struct mbuf *, size_t);
236 
237 struct lltable *in_lltable_get(struct ifnet *ifp);
238 struct lltable *in6_lltable_get(struct ifnet *ifp);
239 struct lltable *lltable_get(struct ifnet *ifp, int family);
240 
241 size_t		llentry_free(struct llentry *);
242 
243 /* helper functions */
244 size_t lltable_drop_entry_queue(struct llentry *);
245 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
246     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
247 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
248     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
249 
250 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
251     char *buf, size_t *bufsize, int *lladdr_off);
252 void lltable_update_ifaddr(struct lltable *llt);
253 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
254     const struct sockaddr *l4addr);
255 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
256 int lltable_delete_addr(struct lltable *llt, u_int flags,
257     const struct sockaddr *l3addr);
258 int lltable_link_entry(struct lltable *llt, struct llentry *lle);
259 int lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
260 void lltable_link_child_entry(struct llentry *parent_lle, struct llentry *child_lle);
261 void lltable_unlink_child_entry(struct llentry *child_lle);
262 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
263 struct ifnet *lltable_get_ifp(const struct lltable *llt);
264 int lltable_get_af(const struct lltable *llt);
265 
266 bool lltable_acquire_wlock(struct ifnet *ifp, struct llentry *lle);
267 
268 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
269     void *farg);
270 void lltable_delete_conditional(struct lltable *llt, llt_match_cb_t *func,
271     void *farg);
272 
273 /*
274  * Generic link layer address lookup function.
275  */
276 static __inline struct llentry *
277 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
278 {
279 
280 	return (llt->llt_lookup(llt, flags, l3addr));
281 }
282 
283 void llentry_request_feedback(struct llentry *lle);
284 void llentry_mark_used(struct llentry *lle);
285 time_t llentry_get_hittime(struct llentry *lle);
286 int llentry_get_upper_family(const struct llentry *lle, int default_family);
287 
288 /*
289  * Notify the LLE code that the entry was used by datapath.
290  */
291 static __inline void
292 llentry_provide_feedback(struct llentry *lle)
293 {
294 
295 	if (__predict_true(lle->r_skip_req == 0))
296 		return;
297 	llentry_mark_used(lle);
298 }
299 struct llentry *llentry_lookup_family(struct llentry *lle, int family);
300 
301 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
302 
303 enum {
304 	LLENTRY_RESOLVED,
305 	LLENTRY_TIMEDOUT,
306 	LLENTRY_DELETED,
307 	LLENTRY_EXPIRED,
308 };
309 typedef void (*lle_event_fn)(void *, struct llentry *, int);
310 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
311 #endif  /* _NET_IF_LLATBL_H_ */
312