freebsd-src/sys/net/hostcache.h
Peter Wemm 664a31e496 Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.
1999-12-29 04:46:21 +00:00

96 lines
3.4 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.
*
* $FreeBSD$
*/
#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 */