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