Annotation of XNU/bsd/net/hostcache.h, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
                      3:  *
                      4:  * @APPLE_LICENSE_HEADER_START@
                      5:  * 
                      6:  * The contents of this file constitute Original Code as defined in and
                      7:  * are subject to the Apple Public Source License Version 1.1 (the
                      8:  * "License").  You may not use this file except in compliance with the
                      9:  * License.  Please obtain a copy of the License at
                     10:  * http://www.apple.com/publicsource and read it before using this file.
                     11:  * 
                     12:  * This Original Code and all software distributed under the License are
                     13:  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
                     14:  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
                     15:  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
                     16:  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
                     17:  * License for the specific language governing rights and limitations
                     18:  * under the License.
                     19:  * 
                     20:  * @APPLE_LICENSE_HEADER_END@
                     21:  */
                     22: /*
                     23:  * Copyright 1997 Massachusetts Institute of Technology
                     24:  *
                     25:  * Permission to use, copy, modify, and distribute this software and
                     26:  * its documentation for any purpose and without fee is hereby
                     27:  * granted, provided that both the above copyright notice and this
                     28:  * permission notice appear in all copies, that both the above
                     29:  * copyright notice and this permission notice appear in all
                     30:  * supporting documentation, and that the name of M.I.T. not be used
                     31:  * in advertising or publicity pertaining to distribution of the
                     32:  * software without specific, written prior permission.  M.I.T. makes
                     33:  * no representations about the suitability of this software for any
                     34:  * purpose.  It is provided "as is" without express or implied
                     35:  * warranty.
                     36:  * 
                     37:  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
                     38:  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
                     39:  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
                     40:  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
                     41:  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
                     42:  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
                     43:  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
                     44:  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
                     45:  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
                     46:  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
                     47:  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     48:  * SUCH DAMAGE.
                     49:  *
                     50:  */
                     51: 
                     52: #ifndef _NET_HOSTCACHE_H
                     53: #define        _NET_HOSTCACHE_H        1
                     54: 
                     55: /*
                     56:  * This file defines the interface between network protocols and
                     57:  * the cache of host-specific information maintained by the kernel.
                     58:  * The generic interface takes care of inserting and deleting entries,
                     59:  * maintaining mutual exclusion, and enforcing policy constraint on the
                     60:  * size of the cache and the maximum age of its entries.
                     61:  * It replaces an earlier scheme which overloaded the routing table
                     62:  * for this purpose, and should be significantly more efficient
                     63:  * at performing most operations.  (It does keep a route to each
                     64:  * entry in the cache.)  Most protocols will want to define a
                     65:  * structure which begins with `struct hcentry' so that they
                     66:  * can keep additional, protocol-specific information in it.
                     67:  */
                     68: 
                     69: #include <sys/queue.h>
                     70: 
                     71: struct hcentry {
                     72:        LIST_ENTRY(hcentry) hc_link;
                     73:        struct  timeval hc_idlesince;   /* time last ref dropped */
                     74:        struct  sockaddr *hc_host;      /* address of this entry's host */
                     75:        struct  rtentry *hc_rt;         /* route to get there */
                     76:        /* struct nexthop *hc_nh; */
                     77:        int     hc_refcnt;              /* reference count */
                     78:        struct  hctable *hc_hct;        /* back ref to table */
                     79: };
                     80: 
                     81: struct hccallback {
                     82:        u_long  (*hccb_hash)(struct sockaddr *, u_long);
                     83:        int     (*hccb_delete)(struct hcentry *);
                     84:        u_long  (*hccb_bump)(u_long);
                     85: };
                     86: 
                     87: LIST_HEAD(hchead, hcentry);
                     88: 
                     89: struct hctable {
                     90:        u_long  hct_nentries;
                     91:        u_long  hct_active;
                     92:        u_long  hct_idle;
                     93:        struct  hchead *hct_heads;
                     94:        struct  hccallback *hct_cb;
                     95:        int     hct_primes;
                     96: };
                     97: 
                     98: #ifdef KERNEL
                     99: 
                    100: #ifdef MALLOC_DECLARE
                    101: MALLOC_DECLARE(M_HOSTCACHE);
                    102: #endif
                    103: /*
                    104:  * The table-modification functions must be called from user mode, as
                    105:  * they may block waiting for memory and/or locks.
                    106:  */
                    107: int    hc_init(int af, struct hccallback *hccb, int init_nelem, int primes);
                    108: struct hcentry *hc_get(struct sockaddr *sa);
                    109: void   hc_ref(struct hcentry *hc);
                    110: void   hc_rele(struct hcentry *hc);
                    111: int    hc_insert(struct hcentry *hc);
                    112: int    hc_delete(struct hcentry *hc);
                    113: #endif /* KERNEL */
                    114: 
                    115: #endif /* _NET_HOSTCACHE_H */

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