1/* BGP flap dampening
2   Copyright (C) 2001 IP Infusion Inc.
3
4This file is part of GNU Zebra.
5
6GNU Zebra is free software; you can redistribute it and/or modify it
7under the terms of the GNU General Public License as published by the
8Free Software Foundation; either version 2, or (at your option) any
9later version.
10
11GNU Zebra is distributed in the hope that it will be useful, but
12WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU Zebra; see the file COPYING.  If not, write to the Free
18Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
1902111-1307, USA.  */
20
21#ifndef _QUAGGA_BGP_DAMP_H
22#define _QUAGGA_BGP_DAMP_H
23
24/* Structure maintained on a per-route basis. */
25struct 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. */
66struct 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
132extern int bgp_damp_enable (struct bgp *, afi_t, safi_t, time_t, unsigned int,
133                     unsigned int, time_t);
134extern int bgp_damp_disable (struct bgp *, afi_t, safi_t);
135extern int bgp_damp_withdraw (struct bgp_info *, struct bgp_node *,
136		       afi_t, safi_t, int);
137extern int bgp_damp_update (struct bgp_info *, struct bgp_node *, afi_t, safi_t);
138extern int bgp_damp_scan (struct bgp_info *, afi_t, safi_t);
139extern void bgp_damp_info_free (struct bgp_damp_info *, int);
140extern void bgp_damp_info_clean (void);
141extern int bgp_damp_decay (time_t, int);
142extern void bgp_config_write_damp (struct vty *);
143extern void bgp_damp_info_vty (struct vty *, struct bgp_info *);
144extern const char * bgp_damp_reuse_time_vty (struct vty *, struct bgp_info *,
145                                             char *, size_t);
146
147#endif /* _QUAGGA_BGP_DAMP_H */
148