92 lines
3.3 KiB
C
92 lines
3.3 KiB
C
|
/*
|
||
|
|
* 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.
|
||
|
|
*
|
||
|
|
* $Id$
|
||
|
|
*/
|
||
|
|
|
||
|
|
#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
|
||
|
|
/*
|
||
|
|
* 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 /* KERNEL */
|
||
|
|
|
||
|
|
#endif /* _NET_HOSTCACHE_H */
|