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/* BGP flap dampening
Copyright (C) 2001 IP Infusion Inc.
This file is part of GNU Zebra.
GNU Zebra is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.
GNU Zebra is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU Zebra; see the file COPYING. If not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
/* Structure maintained on a per-route basis. */
struct bgp_damp_info
{
/* Doubly linked list. This information must be linked to
reuse_list or no_reuse_list. */
struct bgp_damp_info *next;
struct bgp_damp_info *prev;
/* Figure-of-merit. */
int penalty;
/* Number of flapping. */
int flap;
/* First flap time */
time_t start_time;
/* Last time penalty was updated. */
time_t t_updated;
/* Time of route start to be suppressed. */
time_t suppress_time;
/* Back reference to bgp_info. */
struct bgp_info *binfo;
/* Back reference to bgp_node. */
struct bgp_node *rn;
/* Current index in the reuse_list. */
int index;
/* Last time message type. */
u_char lastrecord;
#define BGP_RECORD_UPDATE 1
#define BGP_RECORD_WITHDRAW 2
afi_t afi;
safi_t safi;
};
/* Specified parameter set configuration. */
struct bgp_damp_config
{
/* Value over which routes suppressed. */
int suppress_value;
/* Value below which suppressed routes reused. */
int reuse_limit;
/* Max time a route can be suppressed. */
int max_suppress_time;
/* Time during which accumulated penalty reduces by half. */
int half_life;
/* Non-configurable parameters but fixed at implementation time.
* To change this values, init_bgp_damp() should be modified.
*/
int tmax; /* Max time previous instability retained */
int reuse_list_size; /* Number of reuse lists */
int reuse_index_size; /* Size of reuse index array */
/* Non-configurable parameters. Most of these are calculated from
* the configurable parameters above.
*/
unsigned int ceiling; /* Max value a penalty can attain */
int decay_rate_per_tick; /* Calculated from half-life */
int decay_array_size; /* Calculated using config parameters */
double scale_factor;
int reuse_scale_factor;
/* Decay array per-set based. */
double *decay_array;
/* Reuse index array per-set based. */
int *reuse_index;
/* Reuse list array per-set based. */
struct bgp_damp_info **reuse_list;
int reuse_offset;
/* All dampening information which is not on reuse list. */
struct bgp_damp_info *no_reuse_list;
/* Reuse timer thread per-set base. */
struct thread* t_reuse;
};
#define BGP_DAMP_NONE 0
#define BGP_DAMP_USED 1
#define BGP_DAMP_SUPPRESSED 2
/* Time granularity for reuse lists */
#define DELTA_REUSE 10
/* Time granularity for decay arrays */
#define DELTA_T 5
#define DEFAULT_PENALTY 1000
#define DEFAULT_HALF_LIFE 15
#define DEFAULT_REUSE 750
#define DEFAULT_SUPPRESS 2000
#define REUSE_LIST_SIZE 256
#define REUSE_ARRAY_SIZE 1024
int bgp_damp_enable (struct bgp *, afi_t, safi_t, int, int, int, int);
int bgp_damp_disable (struct bgp *, afi_t, safi_t);
int bgp_damp_withdraw (struct bgp_info *, struct bgp_node *,
afi_t, safi_t, int);
int bgp_damp_update (struct bgp_info *, struct bgp_node *, afi_t, safi_t);
int bgp_damp_scan (struct bgp_info *, afi_t, safi_t);
void bgp_damp_info_free (struct bgp_damp_info *, int);
void bgp_damp_info_clean ();
char * bgp_get_reuse_time (int, char*, size_t);
int bgp_damp_decay (time_t, int);
int bgp_config_write_damp (struct vty *);
void bgp_damp_info_vty (struct vty *, struct bgp_info *);
char * bgp_damp_reuse_time_vty (struct vty *, struct bgp_info *);
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