bsd/netat/at_ddp_brt.h

   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 /*
  24  *      Copyright (c) 1988, 1989 Apple Computer, Inc.
  25  */
  26
  27 #ifndef _NETAT_AT_DDP_BRT_H_
  28 #define _NETAT_AT_DDP_BRT_H_
  29
  30 typedef struct {
  31         int                             age_flag;
  32         at_ifaddr_t                     *ifID;
  33         struct  etalk_addr              et_addr;
  34         at_net_al                       net;
  35 } ddp_brt_t;
  36
  37 #define BRT_SWEEP_INT           (10 * PR_SLOWHZ)
  38 #define BRT_BSIZ                 4      /* bucket size */
  39 #define BRT_NB                  16      /* number of buckets */
  40 #define BRTSIZE                 (BRT_BSIZ * BRT_NB)
  41
  42 /* age_flag values */
  43 #define BRT_EMPTY               0       /* the BRT entry is empty     */
  44                                         /* (or aged out).             */
  45 #define BRT_VALID               1       /* BRT entry contains valid   */
  46                                         /* tuple                      */
  47 #define BRT_GETTING_OLD         2       /* BRT entry is a candidate   */
  48                                         /* for aging                  */
  49
  50 #define BRT_HASH(a)   ((a) % BRT_NB)
  51
  52 #define BRT_LOOK(brt, dst_net) {                                \
  53         register n;                                             \
  54         brt = &at_ddp_brt[BRT_HASH(dst_net) * BRT_BSIZ];        \
  55         for (n = 0 ; ; brt++) {                                 \
  56                 if (brt->net == dst_net)                        \
  57                         break;                                  \
  58                 if (++n >= BRT_BSIZ) {                          \
  59                         brt = NULL;                             \
  60                         break;                                  \
  61                 }                                               \
  62         }                                                       \
  63         }
  64
  65 #define NEW_BRT(brt, net) {                                     \
  66         register n;                                             \
  67         brt = &at_ddp_brt[BRT_HASH(net) * BRT_BSIZ];            \
  68         for (n = 0 ; ; brt++) {                                 \
  69                 if (brt->age_flag == BRT_EMPTY)                 \
  70                         break;                                  \
  71                 if (++n >= BRT_BSIZ) {                          \
  72                         brt = NULL;                             \
  73                         break;                                  \
  74                 }                                               \
  75         }                                                       \
  76         }
  77
  78 /* Best Router Cache */
  79 extern  ddp_brt_t       at_ddp_brt[BRTSIZE];
  80
  81 #endif /* _NETAT_AT_DDP_BRT_H_ */
  82