2 * Copyright 1997 Massachusetts Institute of Technology
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
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9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission. M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose. It is provided "as is" without express or implied
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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29 * $FreeBSD: src/sys/net/hostcache.h,v 1.4 1999/12/29 04:38:32 peter Exp $
30 * $DragonFly: src/sys/net/Attic/hostcache.h,v 1.2 2003/06/17 04:28:47 dillon Exp $
33 #ifndef _NET_HOSTCACHE_H
34 #define _NET_HOSTCACHE_H 1
37 * This file defines the interface between network protocols and
38 * the cache of host-specific information maintained by the kernel.
39 * The generic interface takes care of inserting and deleting entries,
40 * maintaining mutual exclusion, and enforcing policy constraint on the
41 * size of the cache and the maximum age of its entries.
42 * It replaces an earlier scheme which overloaded the routing table
43 * for this purpose, and should be significantly more efficient
44 * at performing most operations. (It does keep a route to each
45 * entry in the cache.) Most protocols will want to define a
46 * structure which begins with `struct hcentry' so that they
47 * can keep additional, protocol-specific information in it.
50 #include <sys/queue.h>
53 LIST_ENTRY(hcentry) hc_link;
54 struct timeval hc_idlesince; /* time last ref dropped */
55 struct sockaddr *hc_host; /* address of this entry's host */
56 struct rtentry *hc_rt; /* route to get there */
57 /* struct nexthop *hc_nh; */
58 int hc_refcnt; /* reference count */
59 struct hctable *hc_hct; /* back ref to table */
63 u_long (*hccb_hash)(struct sockaddr *, u_long);
64 int (*hccb_delete)(struct hcentry *);
65 u_long (*hccb_bump)(u_long);
68 LIST_HEAD(hchead, hcentry);
74 struct hchead *hct_heads;
75 struct hccallback *hct_cb;
82 MALLOC_DECLARE(M_HOSTCACHE);
85 * The table-modification functions must be called from user mode, as
86 * they may block waiting for memory and/or locks.
88 int hc_init(int af, struct hccallback *hccb, int init_nelem, int primes);
89 struct hcentry *hc_get(struct sockaddr *sa);
90 void hc_ref(struct hcentry *hc);
91 void hc_rele(struct hcentry *hc);
92 int hc_insert(struct hcentry *hc);
93 int hc_delete(struct hcentry *hc);
96 #endif /* _NET_HOSTCACHE_H */