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/*
* Copyright 1997 Massachusetts Institute of Technology
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby
* granted, provided that both the above copyright notice and this
* permission notice appear in all copies, that both the above
* copyright notice and this permission notice appear in all
* supporting documentation, and that the name of M.I.T. not be used
* in advertising or publicity pertaining to distribution of the
* software without specific, written prior permission. M.I.T. makes
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied
* warranty.
*
* THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
* ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
* SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NET_HOSTCACHE_H
#define _NET_HOSTCACHE_H 1
/*
* This file defines the interface between network protocols and
* the cache of host-specific information maintained by the kernel.
* The generic interface takes care of inserting and deleting entries,
* maintaining mutual exclusion, and enforcing policy constraint on the
* size of the cache and the maximum age of its entries.
* It replaces an earlier scheme which overloaded the routing table
* for this purpose, and should be significantly more efficient
* at performing most operations. (It does keep a route to each
* entry in the cache.) Most protocols will want to define a
* structure which begins with `struct hcentry' so that they
* can keep additional, protocol-specific information in it.
*/
#include <sys/queue.h>
struct hcentry {
LIST_ENTRY(hcentry) hc_link;
struct timeval hc_idlesince; /* time last ref dropped */
struct sockaddr *hc_host; /* address of this entry's host */
struct rtentry *hc_rt; /* route to get there */
/* struct nexthop *hc_nh; */
int hc_refcnt; /* reference count */
struct hctable *hc_hct; /* back ref to table */
};
struct hccallback {
u_long (*hccb_hash)(struct sockaddr *, u_long);
int (*hccb_delete)(struct hcentry *);
u_long (*hccb_bump)(u_long);
};
LIST_HEAD(hchead, hcentry);
struct hctable {
u_long hct_nentries;
u_long hct_active;
u_long hct_idle;
struct hchead *hct_heads;
struct hccallback *hct_cb;
int hct_primes;
};
#ifdef _KERNEL
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_HOSTCACHE);
#endif
/*
* The table-modification functions must be called from user mode, as
* they may block waiting for memory and/or locks.
*/
int hc_init(int af, struct hccallback *hccb, int init_nelem, int primes);
struct hcentry *hc_get(struct sockaddr *sa);
void hc_ref(struct hcentry *hc);
void hc_rele(struct hcentry *hc);
int hc_insert(struct hcentry *hc);
int hc_delete(struct hcentry *hc);
#endif
#endif /* _NET_HOSTCACHE_H */
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