Commit 5ea39eaa authored by Ondrej Zajicek (work)'s avatar Ondrej Zajicek (work)
Browse files

Nest: Use bitmaps to keep track of exported routes 

Use a hierarchical bitmap in a routing table to assign ids to routes, and
then use bitmaps (indexed by route id) in channels to keep track whether
routes were exported. This avoids unreliable and inefficient re-evaluation
of filters for old routes in order to determine whether they were exported.
parent af02b83b

lib/bitmap.c

+7 −0
Original line number Diff line number Diff line
@@ -26,6 +26,13 @@ bmap_init(struct bmap *b, pool *p, uint size) 
  b->data = mb_allocz(p, b->size);

}



void

bmap_reset(struct bmap *b, uint size)

{

  b->size = BIRD_ALIGN(size, 4);

  memset(b->data, 0, b->size);

}



void

bmap_grow(struct bmap *b, uint need)

{

lib/bitmap.h

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ struct bmap 
};



void bmap_init(struct bmap *b, pool *p, uint size);

void bmap_reset(struct bmap *b, uint size);

void bmap_grow(struct bmap *b, uint need);

void bmap_free(struct bmap *b);

nest/config.Y

+2 −1
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ CF_KEYWORDS(IPV4, IPV6, VPN4, VPN6, ROA4, ROA6, FLOW4, FLOW6, SADR, MPLS) 
CF_KEYWORDS(RECEIVE, LIMIT, ACTION, WARN, BLOCK, RESTART, DISABLE, KEEP, FILTERED)

CF_KEYWORDS(PASSWORD, FROM, PASSIVE, TO, ID, EVENTS, PACKETS, PROTOCOLS, INTERFACES)

CF_KEYWORDS(ALGORITHM, KEYED, HMAC, MD5, SHA1, SHA256, SHA384, SHA512)

CF_KEYWORDS(PRIMARY, STATS, COUNT, BY, FOR, COMMANDS, PREEXPORT, NOEXPORT, GENERATE)

CF_KEYWORDS(PRIMARY, STATS, COUNT, BY, FOR, COMMANDS, PREEXPORT, NOEXPORT, EXPORTED, GENERATE)

CF_KEYWORDS(BGP, PASSWORDS, DESCRIPTION, SORTED)

CF_KEYWORDS(RELOAD, IN, OUT, MRTDUMP, MESSAGES, RESTRICT, MEMORY, IGP_METRIC, CLASS, DSCP)

CF_KEYWORDS(TIMEFORMAT, ISO, SHORT, LONG, ROUTE, PROTOCOL, BASE, LOG, S, MS, US)
@@ -685,6 +685,7 @@ export_mode: 
   PREEXPORT	{ $$ = RSEM_PREEXPORT; }

 | EXPORT	{ $$ = RSEM_EXPORT; }

 | NOEXPORT	{ $$ = RSEM_NOEXPORT; }

 | EXPORTED	{ $$ = RSEM_EXPORTED; }

 ;



/* This is ugly hack */

nest/proto.c

+23 −4
Original line number Diff line number Diff line
@@ -255,6 +255,22 @@ channel_feed_loop(void *ptr) 
    return;

  }



  /* Reset export limit if the feed ended with acceptable number of exported routes */

  struct channel_limit *l = &c->out_limit;

  if (c->refeeding &&

      (l->state == PLS_BLOCKED) &&

      (c->refeed_count <= l->limit) &&

      (c->stats.exp_routes <= l->limit))

  {

    log(L_INFO "Protocol %s resets route export limit (%u)", c->proto->name, l->limit);

    channel_reset_limit(&c->out_limit);



    /* Continue in feed - it will process routing table again from beginning */

    c->refeed_count = 0;

    ev_schedule(c->feed_event);

    return;

  }



  // DBG("Feeding protocol %s finished\n", p->name);

  c->export_state = ES_READY;

  // proto_log_state_change(p);
@@ -282,6 +298,7 @@ channel_stop_export(struct channel *c) 


  c->export_state = ES_DOWN;

  c->stats.exp_routes = 0;

  bmap_reset(&c->export_map, 1024);

}
@@ -360,6 +377,9 @@ channel_do_start(struct channel *c) 


  c->feed_event = ev_new_init(c->proto->pool, channel_feed_loop, c);



  bmap_init(&c->export_map, c->proto->pool, 1024);

  memset(&c->stats, 0, sizeof(struct proto_stats));



  channel_reset_limit(&c->rx_limit);

  channel_reset_limit(&c->in_limit);

  channel_reset_limit(&c->out_limit);
@@ -391,6 +411,7 @@ channel_do_down(struct channel *c) 
  if ((c->stats.imp_routes + c->stats.filt_routes) != 0)

    log(L_ERR "%s: Channel %s is down but still has some routes", c->proto->name, c->name);



  bmap_free(&c->export_map);

  memset(&c->stats, 0, sizeof(struct proto_stats));



  c->in_table = NULL;
@@ -503,10 +524,8 @@ channel_request_feeding(struct channel *c) 
    rt_feed_channel_abort(c);

  }



  channel_reset_limit(&c->out_limit);



  /* Hack: reset exp_routes during refeed, and do not decrease it later */

  c->stats.exp_routes = 0;

  /* Track number of exported routes during refeed */

  c->refeed_count = 0;



  channel_schedule_feed(c, 0);	/* Sets ES_FEEDING */

  // proto_log_state_change(c);

nest/protocol.h

+2 −0
Original line number Diff line number Diff line
@@ -507,6 +507,7 @@ struct channel { 
  struct rtable *table;

  const struct filter *in_filter;	/* Input filter */

  const struct filter *out_filter;	/* Output filter */

  struct bmap export_map;		/* Keeps track which routes passed export filter */

  struct channel_limit rx_limit;	/* Receive limit (for in_keep_filtered) */

  struct channel_limit in_limit;	/* Input limit */

  struct channel_limit out_limit;	/* Output limit */
@@ -514,6 +515,7 @@ struct channel { 
  struct event *feed_event;		/* Event responsible for feeding */

  struct fib_iterator feed_fit;		/* Routing table iterator used during feeding */

  struct proto_stats stats;		/* Per-channel protocol statistics */

  u32 refeed_count;			/* Number of routes exported during refeed regardless of out_limit */



  u8 net_type;				/* Routing table network type (NET_*), 0 for undefined */

  u8 ra_mode;				/* Mode of received route advertisements (RA_*) */

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