xref: /freebsd/sys/net/if_llatbl.h (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #ifndef	_NET_IF_LLATBL_H_
31 #define	_NET_IF_LLATBL_H_
32 
33 #include <sys/_eventhandler.h>
34 #include <sys/_rwlock.h>
35 #include <netinet/in.h>
36 #include <sys/epoch.h>
37 #include <sys/ck.h>
38 
39 struct ifnet;
40 struct sysctl_req;
41 struct rt_msghdr;
42 struct rt_addrinfo;
43 struct llentry;
44 CK_LIST_HEAD(llentries, llentry);
45 
46 #define	LLE_MAX_LINKHDR		24	/* Full IB header */
47 /*
48  * Code referencing llentry must at least hold
49  * a shared lock
50  */
51 struct llentry {
52 	CK_LIST_ENTRY(llentry)	 lle_next;
53 	union {
54 		struct in_addr	addr4;
55 		struct in6_addr	addr6;
56 	} r_l3addr;
57 	char			r_linkdata[LLE_MAX_LINKHDR]; /* L2 data */
58 	uint8_t			r_hdrlen;	/* length for LL header */
59 	uint8_t			r_family;	/* Upper layer proto family */
60 	uint8_t			spare0[2];
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 	CK_SLIST_HEAD(llentry_children_head,llentry)	lle_children;	/* child encaps */
81 	CK_SLIST_ENTRY(llentry)	lle_child_next;	/* child encaps */
82 	struct llentry		*lle_parent;	/* parent for a child */
83 
84 	CK_LIST_ENTRY(llentry)	lle_chain;	/* chain of deleted items */
85 	struct callout		lle_timer;
86 	struct rwlock		 lle_lock;
87 	struct mtx		req_mtx;
88 	struct epoch_context lle_epoch_ctx;
89 };
90 
91 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
92 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
93 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
94 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
95 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
96 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
97 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
98 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
99 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
100 
101 #define	LLE_REQ_INIT(lle)	mtx_init(&(lle)->req_mtx, "lle req", \
102 	NULL, MTX_DEF)
103 #define	LLE_REQ_DESTROY(lle)	mtx_destroy(&(lle)->req_mtx)
104 #define	LLE_REQ_LOCK(lle)	mtx_lock(&(lle)->req_mtx)
105 #define	LLE_REQ_UNLOCK(lle)	mtx_unlock(&(lle)->req_mtx)
106 
107 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
108 
109 #define	LLE_SF(_fam, _flags)	(((_flags) & 0xFFFF) | ((_fam) << 16))
110 
111 #define	LLE_ADDREF(lle) do {					\
112 	LLE_WLOCK_ASSERT(lle);					\
113 	KASSERT((lle)->lle_refcnt >= 0,				\
114 	    ("negative refcnt %d on lle %p",			\
115 	    (lle)->lle_refcnt, (lle)));				\
116 	(lle)->lle_refcnt++;					\
117 } while (0)
118 
119 #define	LLE_REMREF(lle)	do {					\
120 	LLE_WLOCK_ASSERT(lle);					\
121 	KASSERT((lle)->lle_refcnt > 0,				\
122 	    ("bogus refcnt %d on lle %p",			\
123 	    (lle)->lle_refcnt, (lle)));				\
124 	(lle)->lle_refcnt--;					\
125 } while (0)
126 
127 #define	LLE_FREE_LOCKED(lle) do {				\
128 	if ((lle)->lle_refcnt == 1)				\
129 		(lle)->lle_free(lle);				\
130 	else {							\
131 		LLE_REMREF(lle);				\
132 		LLE_WUNLOCK(lle);				\
133 	}							\
134 	/* guard against invalid refs */			\
135 	(lle) = NULL;						\
136 } while (0)
137 
138 #define	LLE_FREE(lle) do {					\
139 	LLE_WLOCK(lle);						\
140 	LLE_FREE_LOCKED(lle);					\
141 } while (0)
142 
143 typedef	struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
144     const struct sockaddr *l3addr);
145 typedef	struct llentry *(llt_alloc_t)(struct lltable *, u_int flags,
146     const struct sockaddr *l3addr);
147 typedef	void (llt_delete_t)(struct lltable *, struct llentry *);
148 typedef void (llt_prefix_free_t)(struct lltable *,
149     const struct sockaddr *addr, const struct sockaddr *mask, u_int flags);
150 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
151     struct sysctl_req *);
152 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
153 typedef int (llt_match_prefix_t)(const struct sockaddr *,
154     const struct sockaddr *, u_int, struct llentry *);
155 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
156 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
157 typedef void (llt_free_tbl_t)(struct lltable *);
158 typedef int (llt_link_entry_t)(struct lltable *, struct llentry *);
159 typedef int (llt_unlink_entry_t)(struct llentry *);
160 typedef void (llt_mark_used_t)(struct llentry *);
161 typedef void (llt_post_resolved_t)(struct lltable *, struct llentry *);
162 
163 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
164 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
165 typedef bool (llt_match_cb_t)(struct lltable *, struct llentry *, void *);
166 
167 struct lltable {
168 	SLIST_ENTRY(lltable)	llt_link;
169 	sa_family_t		llt_af;
170 	uint8_t			llt_flags;
171 	uint8_t			llt_spare[2];
172 	int			llt_hsize;
173 	int			llt_entries;
174 	int			llt_maxentries;
175 	struct llentries	*lle_head;
176 	struct ifnet		*llt_ifp;
177 
178 	llt_lookup_t		*llt_lookup;
179 	llt_alloc_t		*llt_alloc_entry;
180 	llt_delete_t		*llt_delete_entry;
181 	llt_prefix_free_t	*llt_prefix_free;
182 	llt_dump_entry_t	*llt_dump_entry;
183 	llt_hash_t		*llt_hash;
184 	llt_match_prefix_t	*llt_match_prefix;
185 	llt_free_entry_t	*llt_free_entry;
186 	llt_foreach_entry_t	*llt_foreach_entry;
187 	llt_link_entry_t	*llt_link_entry;
188 	llt_unlink_entry_t	*llt_unlink_entry;
189 	llt_fill_sa_entry_t	*llt_fill_sa_entry;
190 	llt_free_tbl_t		*llt_free_tbl;
191 	llt_mark_used_t		*llt_mark_used;
192 	llt_post_resolved_t	*llt_post_resolved;
193 };
194 
195 MALLOC_DECLARE(M_LLTABLE);
196 
197 /*
198  * LLtable flags
199  */
200 #define	LLT_ADDEDPROXY	0x01	/* added a proxy llentry */
201 
202 /*
203  * LLentry flags
204  */
205 #define	LLE_DELETED	0x0001	/* entry must be deleted */
206 #define	LLE_STATIC	0x0002	/* entry is static */
207 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
208 #define	LLE_VALID	0x0008	/* ll_addr is valid */
209 #define	LLE_REDIRECT	0x0010	/* installed by redirect; has host rtentry */
210 #define	LLE_PUB		0x0020	/* publish entry ??? */
211 #define	LLE_LINKED	0x0040	/* linked to lookup structure */
212 #define	LLE_CHILD	0x0080	/* Child LLE storing different AF encap */
213 /* LLE request flags */
214 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
215 #define	LLE_UNLOCKED	0x4000	/* return lle unlocked */
216 #define	LLE_ADDRONLY	0x4000	/* return lladdr instead of full header */
217 #define	LLE_CREATE	0x8000	/* hint to avoid lle lookup */
218 
219 /* LLE flags used by fastpath code */
220 #define	RLLE_VALID	0x0001		/* entry is valid */
221 #define	RLLE_IFADDR	LLE_IFADDR	/* entry is ifaddr */
222 
223 #define LLATBL_HASH(key, mask) \
224 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
225 
226 struct lltable *lltable_allocate_htbl(uint32_t hsize);
227 void		lltable_free(struct lltable *);
228 void		lltable_link(struct lltable *llt);
229 void		lltable_prefix_free(int, struct sockaddr *,
230 		    struct sockaddr *, u_int);
231 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
232 size_t		lltable_append_entry_queue(struct llentry *,
233 		    struct mbuf *, size_t);
234 
235 struct lltable *in_lltable_get(struct ifnet *ifp);
236 struct lltable *in6_lltable_get(struct ifnet *ifp);
237 struct lltable *lltable_get(struct ifnet *ifp, int family);
238 
239 size_t		llentry_free(struct llentry *);
240 
241 /* helper functions */
242 size_t lltable_drop_entry_queue(struct llentry *);
243 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
244     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
245 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
246     const char *linkhdr, size_t linkhdrsize, int lladdr_off);
247 
248 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
249     char *buf, size_t *bufsize, int *lladdr_off);
250 void lltable_update_ifaddr(struct lltable *llt);
251 struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
252     const struct sockaddr *l4addr);
253 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
254 int lltable_delete_addr(struct lltable *llt, u_int flags,
255     const struct sockaddr *l3addr);
256 int lltable_link_entry(struct lltable *llt, struct llentry *lle);
257 int lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
258 void lltable_link_child_entry(struct llentry *parent_lle, struct llentry *child_lle);
259 void lltable_unlink_child_entry(struct llentry *child_lle);
260 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
261 struct ifnet *lltable_get_ifp(const struct lltable *llt);
262 int lltable_get_af(const struct lltable *llt);
263 
264 bool lltable_acquire_wlock(struct ifnet *ifp, struct llentry *lle);
265 
266 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
267     void *farg);
268 void lltable_delete_conditional(struct lltable *llt, llt_match_cb_t *func,
269     void *farg);
270 
271 /*
272  * Generic link layer address lookup function.
273  */
274 static __inline struct llentry *
275 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
276 {
277 
278 	return (llt->llt_lookup(llt, flags, l3addr));
279 }
280 
281 void llentry_request_feedback(struct llentry *lle);
282 void llentry_mark_used(struct llentry *lle);
283 time_t llentry_get_hittime(struct llentry *lle);
284 int llentry_get_upper_family(const struct llentry *lle, int default_family);
285 
286 /*
287  * Notify the LLE code that the entry was used by datapath.
288  */
289 static __inline void
290 llentry_provide_feedback(struct llentry *lle)
291 {
292 
293 	if (__predict_true(lle->r_skip_req == 0))
294 		return;
295 	llentry_mark_used(lle);
296 }
297 struct llentry *llentry_lookup_family(struct llentry *lle, int family);
298 
299 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
300 
301 enum {
302 	LLENTRY_RESOLVED,
303 	LLENTRY_TIMEDOUT,
304 	LLENTRY_DELETED,
305 	LLENTRY_EXPIRED,
306 };
307 typedef void (*lle_event_fn)(void *, struct llentry *, int);
308 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
309 #endif  /* _NET_IF_LLATBL_H_ */
310