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Diffstat (limited to 'sys/net/hostcache.h')
| -rw-r--r-- | sys/net/hostcache.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/sys/net/hostcache.h b/sys/net/hostcache.h new file mode 100644 index 0000000..6ffb9ac --- /dev/null +++ b/sys/net/hostcache.h @@ -0,0 +1,95 @@ +/* + * 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 /* KERNEL */ + +#endif /* _NET_HOSTCACHE_H */ |
