xref: /freebsd/sys/net/if_llatbl.h (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
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 /*
45  * Code referencing llentry must at least hold
46  * a shared lock
47  */
48 struct llentry {
49 	LIST_ENTRY(llentry)	 lle_next;
50 	struct rwlock		 lle_lock;
51 	struct lltable		 *lle_tbl;
52 	struct llentries	 *lle_head;
53 	struct mbuf		 *la_hold;
54 	time_t			 la_expire;
55 	uint16_t		 la_flags;
56 	uint16_t		 la_asked;
57 	uint16_t		 la_preempt;
58 	uint16_t		 ln_byhint;
59 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
60 	uint16_t		 ln_router;
61 	time_t			 ln_ntick;
62 	int			 lle_refcnt;
63 
64 	union {
65 		uint64_t	mac_aligned;
66 		uint16_t	mac16[3];
67 	} ll_addr;
68 
69 	/* XXX af-private? */
70 	union {
71 		struct callout	ln_timer_ch;
72 		struct callout  la_timer;
73 	} lle_timer;
74 	/* NB: struct sockaddr must immediately follow */
75 };
76 
77 #define	LLE_WLOCK(lle)		rw_wlock(&(lle)->lle_lock)
78 #define	LLE_RLOCK(lle)		rw_rlock(&(lle)->lle_lock)
79 #define	LLE_WUNLOCK(lle)	rw_wunlock(&(lle)->lle_lock)
80 #define	LLE_RUNLOCK(lle)	rw_runlock(&(lle)->lle_lock)
81 #define	LLE_DOWNGRADE(lle)	rw_downgrade(&(lle)->lle_lock)
82 #define	LLE_TRY_UPGRADE(lle)	rw_try_upgrade(&(lle)->lle_lock)
83 #define	LLE_LOCK_INIT(lle)	rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
84 #define	LLE_LOCK_DESTROY(lle)	rw_destroy(&(lle)->lle_lock)
85 #define	LLE_WLOCK_ASSERT(lle)	rw_assert(&(lle)->lle_lock, RA_WLOCKED)
86 
87 #define LLE_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
88 
89 #define	LLE_ADDREF(lle) do {					\
90 	LLE_WLOCK_ASSERT(lle);					\
91 	KASSERT((lle)->lle_refcnt >= 0,				\
92 		("negative refcnt %d", (lle)->lle_refcnt));	\
93 	(lle)->lle_refcnt++;					\
94 } while (0)
95 
96 #define	LLE_REMREF(lle)	do {					\
97 	LLE_WLOCK_ASSERT(lle);					\
98 	KASSERT((lle)->lle_refcnt > 1,				\
99 		("bogus refcnt %d", (lle)->lle_refcnt));	\
100 	(lle)->lle_refcnt--;					\
101 } while (0)
102 
103 #define	LLE_FREE_LOCKED(lle) do {				\
104 	if ((lle)->lle_refcnt <= 1)				\
105 		(lle)->lle_tbl->llt_free((lle)->lle_tbl, (lle));\
106 	else {							\
107 		(lle)->lle_refcnt--;				\
108 		LLE_WUNLOCK(lle);				\
109 	}							\
110 	/* guard against invalid refs */			\
111 	lle = 0;						\
112 } while (0)
113 
114 #define	LLE_FREE(lle) do {					\
115 	LLE_WLOCK(lle);						\
116 	if ((lle)->lle_refcnt <= 1)				\
117 		(lle)->lle_tbl->llt_free((lle)->lle_tbl, (lle));\
118 	else {							\
119 		(lle)->lle_refcnt--;				\
120 		LLE_WUNLOCK(lle);				\
121 	}							\
122 	/* guard against invalid refs */			\
123 	lle = NULL;						\
124 } while (0)
125 
126 
127 #define	ln_timer_ch	lle_timer.ln_timer_ch
128 #define	la_timer	lle_timer.la_timer
129 
130 /* XXX bad name */
131 #define	L3_ADDR(lle)	((struct sockaddr *)(&lle[1]))
132 #define	L3_ADDR_LEN(lle)	(((struct sockaddr *)(&lle[1]))->sa_len)
133 
134 #ifndef LLTBL_HASHTBL_SIZE
135 #define	LLTBL_HASHTBL_SIZE	32	/* default 32 ? */
136 #endif
137 
138 #ifndef LLTBL_HASHMASK
139 #define	LLTBL_HASHMASK	(LLTBL_HASHTBL_SIZE - 1)
140 #endif
141 
142 struct lltable {
143 	SLIST_ENTRY(lltable)	llt_link;
144 	struct llentries	lle_head[LLTBL_HASHTBL_SIZE];
145 	int			llt_af;
146 	struct ifnet		*llt_ifp;
147 
148 	struct llentry *	(*llt_new)(const struct sockaddr *, u_int);
149 	void			(*llt_free)(struct lltable *, struct llentry *);
150 	struct llentry *	(*llt_lookup)(struct lltable *, u_int flags,
151 				    const struct sockaddr *l3addr);
152 	int			(*llt_rtcheck)(struct ifnet *,
153 				    const struct sockaddr *);
154 	int			(*llt_dump)(struct lltable *,
155 				     struct sysctl_req *);
156 };
157 MALLOC_DECLARE(M_LLTABLE);
158 
159 /*
160  * flags to be passed to arplookup.
161  */
162 #define	LLE_DELETED	0x0001	/* entry must be deleted */
163 #define	LLE_STATIC	0x0002	/* entry is static */
164 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
165 #define	LLE_VALID	0x0008	/* ll_addr is valid */
166 #define	LLE_PROXY	0x0010	/* proxy entry ??? */
167 #define	LLE_PUB		0x0020	/* publish entry ??? */
168 #define	LLE_DELETE	0x4000	/* delete on a lookup - match LLE_IFADDR */
169 #define	LLE_CREATE	0x8000	/* create on a lookup miss */
170 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
171 
172 #define LLATBL_HASH(key, mask) \
173 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
174 
175 struct lltable *lltable_init(struct ifnet *, int);
176 void		lltable_free(struct lltable *);
177 void		lltable_drain(int);
178 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
179 
180 void		llentry_free(struct llentry *);
181 
182 /*
183  * Generic link layer address lookup function.
184  */
185 static __inline struct llentry *
186 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
187 {
188 	return llt->llt_lookup(llt, flags, l3addr);
189 }
190 
191 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
192 #endif  /* _NET_IF_LLATBL_H_ */
193