xref: /freebsd/sys/net/if_llatbl.h (revision fb2971ccd2bab42f5406f919812ceb8e014773ea)
1 /*
2  * Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
3  * Copyright (c) 2004-2008 Qing Li. All rights reserved.
4  * Copyright (c) 2008 Kip Macy. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #ifndef	_NET_IF_LLATBL_H_
31 #define	_NET_IF_LLATBL_H_
32 
33 #include <sys/_rwlock.h>
34 #include <netinet/in.h>
35 
36 struct ifnet;
37 struct sysctl_req;
38 struct rt_msghdr;
39 struct rt_addrinfo;
40 
41 struct llentry;
42 LIST_HEAD(llentries, llentry);
43 
44 extern struct rwlock lltable_rwlock;
45 #define	LLTABLE_RLOCK()		rw_rlock(&lltable_rwlock)
46 #define	LLTABLE_RUNLOCK()	rw_runlock(&lltable_rwlock)
47 #define	LLTABLE_WLOCK()		rw_wlock(&lltable_rwlock)
48 #define	LLTABLE_WUNLOCK()	rw_wunlock(&lltable_rwlock)
49 #define	LLTABLE_LOCK_ASSERT()	rw_assert(&lltable_rwlock, RA_LOCKED)
50 
51 /*
52  * Code referencing llentry must at least hold
53  * a shared lock
54  */
55 struct llentry {
56 	LIST_ENTRY(llentry)	 lle_next;
57 	struct rwlock		 lle_lock;
58 	struct lltable		 *lle_tbl;
59 	struct llentries	 *lle_head;
60 	struct mbuf		 *la_hold;
61 	time_t			 la_expire;
62 	uint16_t		 la_flags;
63 	uint16_t		 la_asked;
64 	uint16_t		 la_preempt;
65 	uint16_t		 ln_byhint;
66 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
67 	uint16_t		 ln_router;
68 	time_t			 ln_ntick;
69 	int			 lle_refcnt;
70 
71 	union {
72 		uint64_t	mac_aligned;
73 		uint16_t	mac16[3];
74 	} ll_addr;
75 
76 	/* XXX af-private? */
77 	union {
78 		struct callout	ln_timer_ch;
79 		struct callout  la_timer;
80 	} lle_timer;
81 	/* NB: struct sockaddr must immediately follow */
82 };
83 
84 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
85 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
86 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
87 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
88 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
89 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
90 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
91 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
92 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
93 
94 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
95 
96 #define	LLE_ADDREF(lle) do {					\
97 	LLE_WLOCK_ASSERT(lle);					\
98 	KASSERT((lle)->lle_refcnt >= 0,				\
99 		("negative refcnt %d", (lle)->lle_refcnt));	\
100 	(lle)->lle_refcnt++;					\
101 } while (0)
102 
103 #define	LLE_REMREF(lle)	do {					\
104 	LLE_WLOCK_ASSERT(lle);					\
105 	KASSERT((lle)->lle_refcnt > 1,				\
106 		("bogus refcnt %d", (lle)->lle_refcnt));	\
107 	(lle)->lle_refcnt--;					\
108 } while (0)
109 
110 #define	LLE_FREE_LOCKED(lle) do {				\
111 	if ((lle)->lle_refcnt <= 1)				\
112 		(lle)->lle_tbl->llt_free((lle)->lle_tbl, (lle));\
113 	else {							\
114 		(lle)->lle_refcnt--;				\
115 		LLE_WUNLOCK(lle);				\
116 	}							\
117 	/* guard against invalid refs */			\
118 	lle = 0;						\
119 } while (0)
120 
121 #define	LLE_FREE(lle) do {					\
122 	LLE_WLOCK(lle);						\
123 	if ((lle)->lle_refcnt <= 1)				\
124 		(lle)->lle_tbl->llt_free((lle)->lle_tbl, (lle));\
125 	else {							\
126 		(lle)->lle_refcnt--;				\
127 		LLE_WUNLOCK(lle);				\
128 	}							\
129 	/* guard against invalid refs */			\
130 	lle = NULL;						\
131 } while (0)
132 
133 
134 #define	ln_timer_ch	lle_timer.ln_timer_ch
135 #define	la_timer	lle_timer.la_timer
136 
137 /* XXX bad name */
138 #define	L3_ADDR(lle)	((struct sockaddr *)(&lle[1]))
139 #define	L3_ADDR_LEN(lle)	(((struct sockaddr *)(&lle[1]))->sa_len)
140 
141 #ifndef LLTBL_HASHTBL_SIZE
142 #define	LLTBL_HASHTBL_SIZE	32	/* default 32 ? */
143 #endif
144 
145 #ifndef LLTBL_HASHMASK
146 #define	LLTBL_HASHMASK	(LLTBL_HASHTBL_SIZE - 1)
147 #endif
148 
149 struct lltable {
150 	SLIST_ENTRY(lltable)	llt_link;
151 	struct llentries	lle_head[LLTBL_HASHTBL_SIZE];
152 	int			llt_af;
153 	struct ifnet		*llt_ifp;
154 
155 	struct llentry *	(*llt_new)(const struct sockaddr *, u_int);
156 	void			(*llt_free)(struct lltable *, struct llentry *);
157 	void			(*llt_prefix_free)(struct lltable *,
158 				    const struct sockaddr *prefix,
159 				    const struct sockaddr *mask);
160 	struct llentry *	(*llt_lookup)(struct lltable *, u_int flags,
161 				    const struct sockaddr *l3addr);
162 	int			(*llt_rtcheck)(struct ifnet *, u_int flags,
163 				    const struct sockaddr *);
164 	int			(*llt_dump)(struct lltable *,
165 				     struct sysctl_req *);
166 };
167 MALLOC_DECLARE(M_LLTABLE);
168 
169 /*
170  * flags to be passed to arplookup.
171  */
172 #define	LLE_DELETED	0x0001	/* entry must be deleted */
173 #define	LLE_STATIC	0x0002	/* entry is static */
174 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
175 #define	LLE_VALID	0x0008	/* ll_addr is valid */
176 #define	LLE_PROXY	0x0010	/* proxy entry ??? */
177 #define	LLE_PUB		0x0020	/* publish entry ??? */
178 #define	LLE_DELETE	0x4000	/* delete on a lookup - match LLE_IFADDR */
179 #define	LLE_CREATE	0x8000	/* create on a lookup miss */
180 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
181 
182 #define LLATBL_HASH(key, mask) \
183 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
184 
185 struct lltable *lltable_init(struct ifnet *, int);
186 void		lltable_free(struct lltable *);
187 void		lltable_prefix_free(int, struct sockaddr *,
188                        struct sockaddr *);
189 #if 0
190 void		lltable_drain(int);
191 #endif
192 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
193 
194 void		llentry_free(struct llentry *);
195 int		llentry_update(struct llentry **, struct lltable *,
196                        struct sockaddr_storage *, struct ifnet *);
197 
198 /*
199  * Generic link layer address lookup function.
200  */
201 static __inline struct llentry *
202 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
203 {
204 	return llt->llt_lookup(llt, flags, l3addr);
205 }
206 
207 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
208 #endif  /* _NET_IF_LLATBL_H_ */
209