bgpd/bgp_damp.h

   1 /* BGP flap dampening
   2    Copyright (C) 2001 IP Infusion Inc.
   3
   4 This file is part of GNU Zebra.
   5
   6 GNU Zebra is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 2, or (at your option) any
   9 later version.
  10
  11 GNU Zebra is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Zebra; see the file COPYING.  If not, write to the Free
  18 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 #ifndef _QUAGGA_BGP_DAMP_H
  22 #define _QUAGGA_BGP_DAMP_H
  23
  24 /* Structure maintained on a per-route basis. */
  25 struct bgp_damp_info
  26 {
  27   /* Doubly linked list.  This information must be linked to
  28      reuse_list or no_reuse_list.  */
  29   struct bgp_damp_info *next;
  30   struct bgp_damp_info *prev;
  31
  32   /* Figure-of-merit.  */
  33   unsigned int penalty;
  34
  35   /* Number of flapping.  */
  36   unsigned int flap;
  37
  38   /* First flap time  */
  39   time_t start_time;
  40
  41   /* Last time penalty was updated.  */
  42   time_t t_updated;
  43
  44   /* Time of route start to be suppressed.  */
  45   time_t suppress_time;
  46
  47   /* Back reference to bgp_info. */
  48   struct bgp_info *binfo;
  49
  50   /* Back reference to bgp_node. */
  51   struct bgp_node *rn;
  52
  53   /* Current index in the reuse_list. */
  54   int index;
  55
  56   /* Last time message type. */
  57   u_char lastrecord;
  58 #define BGP_RECORD_UPDATE       1U
  59 #define BGP_RECORD_WITHDRAW     2U
  60
  61   afi_t afi;
  62   safi_t safi;
  63 };
  64
  65 /* Specified parameter set configuration. */
  66 struct bgp_damp_config
  67 {
  68   /* Value over which routes suppressed.  */
  69   unsigned int suppress_value;
  70
  71   /* Value below which suppressed routes reused.  */
  72   unsigned int reuse_limit;
  73
  74   /* Max time a route can be suppressed.  */
  75   time_t max_suppress_time;
  76
  77   /* Time during which accumulated penalty reduces by half.  */
  78   time_t half_life;
  79
  80   /* Non-configurable parameters but fixed at implementation time.
  81    * To change this values, init_bgp_damp() should be modified.
  82    */
  83   time_t tmax;                   /* Max time previous instability retained */
  84   unsigned int reuse_list_size;  /* Number of reuse lists */
  85   unsigned int reuse_index_size; /* Size of reuse index array */
  86
  87   /* Non-configurable parameters.  Most of these are calculated from
  88    * the configurable parameters above.
  89    */
  90   unsigned int ceiling;                 /* Max value a penalty can attain */
  91   unsigned int decay_rate_per_tick;     /* Calculated from half-life */
  92   unsigned int decay_array_size; /* Calculated using config parameters */
  93   double scale_factor;
  94   unsigned int reuse_scale_factor;
  95
  96   /* Decay array per-set based. */
  97   double *decay_array;
  98
  99   /* Reuse index array per-set based. */
 100   int *reuse_index;
 101
 102   /* Reuse list array per-set based. */
 103   struct bgp_damp_info **reuse_list;
 104   int reuse_offset;
 105
 106   /* All dampening information which is not on reuse list.  */
 107   struct bgp_damp_info *no_reuse_list;
 108
 109   /* Reuse timer thread per-set base. */
 110   struct thread* t_reuse;
 111 };
 112
 113 #define BGP_DAMP_NONE           0
 114 #define BGP_DAMP_USED           1
 115 #define BGP_DAMP_SUPPRESSED     2
 116
 117 /* Time granularity for reuse lists */
 118 #define DELTA_REUSE               10
 119
 120 /* Time granularity for decay arrays */
 121 #define DELTA_T                    5
 122
 123 #define DEFAULT_PENALTY         1000
 124
 125 #define DEFAULT_HALF_LIFE         15
 126 #define DEFAULT_REUSE            750
 127 #define DEFAULT_SUPPRESS        2000
 128
 129 #define REUSE_LIST_SIZE          256
 130 #define REUSE_ARRAY_SIZE        1024
 131
 132 extern int bgp_damp_enable (struct bgp *, afi_t, safi_t, time_t, unsigned int,
 133                      unsigned int, time_t);
 134 extern int bgp_damp_disable (struct bgp *, afi_t, safi_t);
 135 extern int bgp_damp_withdraw (struct bgp_info *, struct bgp_node *,
 136                        afi_t, safi_t, int);
 137 extern int bgp_damp_update (struct bgp_info *, struct bgp_node *, afi_t, safi_t);
 138 extern int bgp_damp_scan (struct bgp_info *, afi_t, safi_t);
 139 extern void bgp_damp_info_free (struct bgp_damp_info *, int);
 140 extern void bgp_damp_info_clean (void);
 141 extern int bgp_damp_decay (time_t, int);
 142 extern void bgp_config_write_damp (struct vty *);
 143 extern void bgp_damp_info_vty (struct vty *, struct bgp_info *);
 144 extern const char * bgp_damp_reuse_time_vty (struct vty *, struct bgp_info *,
 145                                              char *, size_t);
 146
 147 #endif /* _QUAGGA_BGP_DAMP_H */