xref: /freebsd/sys/net/if_llatbl.h (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992)
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 	int     		 la_numheld;  /* # of packets currently held */
62 	time_t			 la_expire;
63 	uint16_t		 la_flags;
64 	uint16_t		 la_asked;
65 	uint16_t		 la_preempt;
66 	uint16_t		 ln_byhint;
67 	int16_t			 ln_state;	/* IPv6 has ND6_LLINFO_NOSTATE == -2 */
68 	uint16_t		 ln_router;
69 	time_t			 ln_ntick;
70 	int			 lle_refcnt;
71 
72 	union {
73 		uint64_t	mac_aligned;
74 		uint16_t	mac16[3];
75 	} ll_addr;
76 
77 	/* XXX af-private? */
78 	union {
79 		struct callout	ln_timer_ch;
80 		struct callout  la_timer;
81 	} lle_timer;
82 	/* NB: struct sockaddr must immediately follow */
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_IS_VALID(lle)	(((lle) != NULL) && ((lle) != (void *)-1))
96 
97 #define	LLE_ADDREF(lle) do {					\
98 	LLE_WLOCK_ASSERT(lle);					\
99 	KASSERT((lle)->lle_refcnt >= 0,				\
100 		("negative refcnt %d", (lle)->lle_refcnt));	\
101 	(lle)->lle_refcnt++;					\
102 } while (0)
103 
104 #define	LLE_REMREF(lle)	do {					\
105 	LLE_WLOCK_ASSERT(lle);					\
106 	KASSERT((lle)->lle_refcnt > 1,				\
107 		("bogus refcnt %d", (lle)->lle_refcnt));	\
108 	(lle)->lle_refcnt--;					\
109 } while (0)
110 
111 #define	LLE_FREE_LOCKED(lle) do {				\
112 	if ((lle)->lle_refcnt <= 1)				\
113 		(lle)->lle_tbl->llt_free((lle)->lle_tbl, (lle));\
114 	else {							\
115 		(lle)->lle_refcnt--;				\
116 		LLE_WUNLOCK(lle);				\
117 	}							\
118 	/* guard against invalid refs */			\
119 	lle = NULL;						\
120 } while (0)
121 
122 #define	LLE_FREE(lle) do {					\
123 	LLE_WLOCK(lle);						\
124 	LLE_FREE_LOCKED(lle);					\
125 } while (0)
126 
127 
128 #define	ln_timer_ch	lle_timer.ln_timer_ch
129 #define	la_timer	lle_timer.la_timer
130 
131 /* XXX bad name */
132 #define	L3_ADDR(lle)	((struct sockaddr *)(&lle[1]))
133 #define	L3_ADDR_LEN(lle)	(((struct sockaddr *)(&lle[1]))->sa_len)
134 
135 #ifndef LLTBL_HASHTBL_SIZE
136 #define	LLTBL_HASHTBL_SIZE	32	/* default 32 ? */
137 #endif
138 
139 #ifndef LLTBL_HASHMASK
140 #define	LLTBL_HASHMASK	(LLTBL_HASHTBL_SIZE - 1)
141 #endif
142 
143 struct lltable {
144 	SLIST_ENTRY(lltable)	llt_link;
145 	struct llentries	lle_head[LLTBL_HASHTBL_SIZE];
146 	int			llt_af;
147 	struct ifnet		*llt_ifp;
148 
149 	struct llentry *	(*llt_new)(const struct sockaddr *, u_int);
150 	void			(*llt_free)(struct lltable *, struct llentry *);
151 	void			(*llt_prefix_free)(struct lltable *,
152 				    const struct sockaddr *prefix,
153 				    const struct sockaddr *mask);
154 	struct llentry *	(*llt_lookup)(struct lltable *, u_int flags,
155 				    const struct sockaddr *l3addr);
156 	int			(*llt_rtcheck)(struct ifnet *, u_int flags,
157 				    const struct sockaddr *);
158 	int			(*llt_dump)(struct lltable *,
159 				     struct sysctl_req *);
160 };
161 MALLOC_DECLARE(M_LLTABLE);
162 
163 /*
164  * flags to be passed to arplookup.
165  */
166 #define	LLE_DELETED	0x0001	/* entry must be deleted */
167 #define	LLE_STATIC	0x0002	/* entry is static */
168 #define	LLE_IFADDR	0x0004	/* entry is interface addr */
169 #define	LLE_VALID	0x0008	/* ll_addr is valid */
170 #define	LLE_PROXY	0x0010	/* proxy entry ??? */
171 #define	LLE_PUB		0x0020	/* publish entry ??? */
172 #define	LLE_DELETE	0x4000	/* delete on a lookup - match LLE_IFADDR */
173 #define	LLE_CREATE	0x8000	/* create on a lookup miss */
174 #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
175 
176 #define LLATBL_HASH(key, mask) \
177 	(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
178 
179 struct lltable *lltable_init(struct ifnet *, int);
180 void		lltable_free(struct lltable *);
181 void		lltable_prefix_free(int, struct sockaddr *,
182                        struct sockaddr *);
183 #if 0
184 void		lltable_drain(int);
185 #endif
186 int		lltable_sysctl_dumparp(int, struct sysctl_req *);
187 
188 size_t		llentry_free(struct llentry *);
189 int		llentry_update(struct llentry **, struct lltable *,
190                        struct sockaddr_storage *, struct ifnet *);
191 
192 /*
193  * Generic link layer address lookup function.
194  */
195 static __inline struct llentry *
196 lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
197 {
198 	return llt->llt_lookup(llt, flags, l3addr);
199 }
200 
201 int		lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
202 #endif  /* _NET_IF_LLATBL_H_ */
203