Commit 682d3f7d authored by Ondrej Zajicek (work)'s avatar Ondrej Zajicek (work)
Browse files

BGP: implement Adj-RIB-In 

The patch implements optional internal import table to a channel and
hooks it to BGP so it can be used as Adj-RIB-In. When enabled, all
received (pre-filtered) routes are stored there and import filters can
be re-evaluated without explicit route refresh. An import table can be
examined using e.g. 'show route import table bgp1.ipv4'.
parent 01fd00f5

nest/config.Y

+10 −0
Original line number Diff line number Diff line
@@ -558,6 +558,16 @@ r_args: 
       rt_show_add_table($$, t->table);

     $$->tables_defined_by = RSD_TDB_ALL;

   }

 | r_args IMPORT TABLE SYM '.' r_args_channel {

     $$ = $1;

     struct proto_config *cf = (void *) $4->def;

     if ($4->class != SYM_PROTO || !cf->proto) cf_error("%s is not a protocol", $4->name);

     struct channel *c = proto_find_channel_by_name(cf->proto, $6);

     if (!c) cf_error("Channel %s.%s not found", $4->name, $6);

     if (!c->in_table) cf_error("No import table in channel %s.%s", $4->name, $6);

     rt_show_add_table($$, c->in_table);

     $$->tables_defined_by = RSD_TDB_DIRECT;

   }

 | r_args FILTER filter {

     $$ = $1;

     if ($$->filter != FILTER_ACCEPT) cf_error("Filter specified twice");

nest/proto.c

+59 −0
Original line number Diff line number Diff line
@@ -284,6 +284,54 @@ channel_stop_export(struct channel *c) 
  c->stats.exp_routes = 0;

}





/* Called by protocol for reload from in_table */

void

channel_schedule_reload(struct channel *c)

{

  ASSERT(c->channel_state == CS_UP);



  rt_reload_channel_abort(c);

  ev_schedule(c->reload_event);

}



static void

channel_reload_loop(void *ptr)

{

  struct channel *c = ptr;



  if (!rt_reload_channel(c))

  {

    ev_schedule(c->reload_event);

    return;

  }

}



static void

channel_reset_import(struct channel *c)

{

  /* Need to abort feeding */

  ev_postpone(c->reload_event);

  rt_reload_channel_abort(c);



  rt_prune_sync(c->in_table, 1);

}



/* Called by protocol to activate in_table */

void

channel_setup_in_table(struct channel *c)

{

  struct rtable_config *cf = mb_allocz(c->proto->pool, sizeof(struct rtable_config));

  cf->name = "import";

  cf->addr_type = c->net_type;



  c->in_table = mb_allocz(c->proto->pool, sizeof(struct rtable));

  rt_setup(c->proto->pool, c->in_table, cf);



  c->reload_event = ev_new_init(c->proto->pool, channel_reload_loop, c);

}





static void

channel_do_start(struct channel *c)

{
@@ -315,6 +363,8 @@ channel_do_flush(struct channel *c) 
static void

channel_do_down(struct channel *c)

{

  ASSERT(!c->feed_active && !c->reload_active);



  rem_node(&c->table_node);

  rt_unlock_table(c->table);

  c->proto->active_channels--;
@@ -324,6 +374,9 @@ channel_do_down(struct channel *c) 


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



  c->in_table = NULL;

  c->reload_event = NULL;



  CALL(c->channel->cleanup, c);



  /* Schedule protocol shutddown */
@@ -355,6 +408,9 @@ channel_set_state(struct channel *c, uint state) 
    if (es != ES_DOWN)

      channel_stop_export(c);



    if (c->in_table && (cs == CS_UP))

      channel_reset_import(c);



    break;



  case CS_UP:
@@ -374,6 +430,9 @@ channel_set_state(struct channel *c, uint state) 
    if (es != ES_DOWN)

      channel_stop_export(c);



    if (c->in_table && (cs == CS_UP))

      channel_reset_import(c);



    channel_do_flush(c);

    break;

nest/protocol.h

+20 −2
Original line number Diff line number Diff line
@@ -306,8 +306,6 @@ rte_make_tmp_attrs(struct rte **rt, struct linpool *pool) 
  (*rt)->attrs->eattrs = ea;

}



/* Moved from route.h to avoid dependency conflicts */

static inline void rte_update(struct proto *p, const net_addr *n, rte *new) { rte_update2(p->main_channel, n, new, p->main_source); }



extern pool *proto_pool;

extern list proto_list;
@@ -539,6 +537,11 @@ struct channel { 


  btime last_state_change;		/* Time of last state transition */

  btime last_tx_filter_change;



  struct rtable *in_table;		/* Internal table for received routes */

  struct event *reload_event;		/* Event responsible for reloading from in_table */

  struct fib_iterator reload_fit;	/* Iterator in in_table used during reloading */

  u8 reload_active;			/* Iterator reload_fit is linked */

};
@@ -606,6 +609,8 @@ struct channel *proto_add_channel(struct proto *p, struct channel_config *cf); 
int proto_configure_channel(struct proto *p, struct channel **c, struct channel_config *cf);



void channel_set_state(struct channel *c, uint state);

void channel_setup_in_table(struct channel *c);

void channel_schedule_reload(struct channel *c);



static inline void channel_init(struct channel *c) { channel_set_state(c, CS_START); }

static inline void channel_open(struct channel *c) { channel_set_state(c, CS_UP); }
@@ -617,4 +622,17 @@ void *channel_config_get(const struct channel_class *cc, const char *name, uint 
int channel_reconfigure(struct channel *c, struct channel_config *cf);





/* Moved from route.h to avoid dependency conflicts */

static inline void rte_update(struct proto *p, const net_addr *n, rte *new) { rte_update2(p->main_channel, n, new, p->main_source); }



static inline void

rte_update3(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)

{

  if (c->in_table && !rte_update_in(c, n, new, src))

    return;



  rte_update2(c, n, new, src);

}





#endif

nest/route.h

+5 −0
Original line number Diff line number Diff line
@@ -311,8 +311,13 @@ void rt_dump(rtable *); 
void rt_dump_all(void);

int rt_feed_channel(struct channel *c);

void rt_feed_channel_abort(struct channel *c);

int rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *src);

int rt_reload_channel(struct channel *c);

void rt_reload_channel_abort(struct channel *c);

void rt_prune_sync(rtable *t, int all);

struct rtable_config *rt_new_table(struct symbol *s, uint addr_type);





/* Default limit for ECMP next hops, defined in sysdep code */

extern const int rt_default_ecmp;

nest/rt-table.c

+121 −0
Original line number Diff line number Diff line
@@ -2288,6 +2288,127 @@ rt_feed_channel_abort(struct channel *c) 
    }

}





int

rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)

{

  rte *old, **pos;

  net *net;



  if (new)

  {

    net = net_get(c->in_table, n);



    if (!new->pref)

      new->pref = c->preference;



    if (!rta_is_cached(new->attrs))

      new->attrs = rta_lookup(new->attrs);

  }

  else

  {

    net = net_find(c->in_table, n);



    if (!net)

      return 0;

  }



  /* Find the old rte */

  for (pos = &net->routes; old = *pos; pos = &old->next)

    if (old->attrs->src == src)

    {

      if (new && rte_same(old, new))

	return 0;



      /* Remove the old rte */

      *pos = old->next;

      rte_free_quick(old);



      break;

    }



  if (!new)

    return !!old;



  /* Insert the new rte */

  rte *e = rte_do_cow(new);

  e->flags |= REF_COW;

  e->net = net;

  e->sender = c;

  e->lastmod = current_time();

  e->next = *pos;

  *pos = e;



  return 1;

}



int

rt_reload_channel(struct channel *c)

{

  struct rtable *tab = c->in_table;

  struct fib_iterator *fit = &c->reload_fit;

  int max_feed = 64;



  ASSERT(c->channel_state == CS_UP);



  if (!c->reload_active)

  {

    FIB_ITERATE_INIT(fit, &tab->fib);

    c->reload_active = 1;

  }



  FIB_ITERATE_START(&tab->fib, fit, net, n)

  {

    if (max_feed <= 0)

    {

      FIB_ITERATE_PUT(fit);

      return 0;

    }



    for (rte *e = n->routes; e; e = e->next)

    {

      rte_update2(c, n->n.addr, rte_do_cow(e), e->attrs->src);

      max_feed--;

    }

  }

  FIB_ITERATE_END;



  c->reload_active = 0;

  return 1;

}



void

rt_reload_channel_abort(struct channel *c)

{

  if (c->reload_active)

  {

    /* Unlink the iterator */

    fit_get(&c->in_table->fib, &c->reload_fit);

    c->reload_active = 0;

  }

}



void

rt_prune_sync(rtable *t, int all)

{

  FIB_WALK(&t->fib, net, n)

  {

    rte *e, **ee = &n->routes;

    while (e = *ee)

    {

      if (all || (e->flags & (REF_STALE | REF_DISCARD)))

      {

	*ee = e->next;

	rte_free_quick(e);

      }

      else

	ee = &e->next;

    }

  }

  FIB_WALK_END;

}





static inline u32

hc_hash(ip_addr a, rtable *dep)

{

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