zebra: add structure to hold per-prefix state in RIB

Add the rib_dest_t structure to hold per-prefix state in the routing
information base. This gives us an appropriate place to maintain the
queueing state of a route_node. Queuing state was previously being
stored on the first rib in the list of ribs hanging off the
route_node.

  * zebra/rib.h

    - Add new structure rib_dest_t.

    - Remove the rn_status field from 'struct rib', it is no longer
      required.

    - Add macros (RNODE_FOREACH_RIB, RNODE_FOREACH_RIB_SAFE) for
      walking all 'struct ribs' corresponding to a route_node. These
      hide the fact that there is an intermediate rib_dest_t
      structure.

    - Add a few utility inlines to go between a rib_dest_t and
      associated structures.

  * zebra/zebra_rib.c

    - rib_link()/rib_unlink()

      Tweak for new behavior, where the 'info' pointer of a route_node
      points to a rib_dest_t. The list of ribs for a prefix now hangs
      off of the dest.

      Change the way we ref count route_nodes. We now hold a single
      ref count on a route_node if there is a corresponding
      rib_dest_t.

    - Maintain the queuing state of a route_node on the flags field of
      the rib_dest_t.

    - Add the rib_gc_dest() function, which deletes a rib_dest_t if it
      is no longer required. A rib_dest_t can be deleted iff there are
      no struct ribs hanging off of it.

    - Call rib_gc_dest() any time we unlink a rib from the
      rib_dest_t. Currently we only need to call it once, just before
      we return from rib_process().

  * zebra/{redistribute,zebra_rib,zebra_snmp,zebra_vty}.c

    Use new macros to walk over route_node ribs.

  * lib/memtypes.c

    Add memory type for rib_dest_t.

Signed-off-by: Avneesh Sachdev <avneesh@opensourcerouting.org>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/zebra/zebra_snmp.c b/zebra/zebra_snmp.c
index f52bbcb8..e06e1443 100644
--- a/zebra/zebra_snmp.c
+++ b/zebra/zebra_snmp.c
@@ -150,7 +150,7 @@ ipFwNumber (struct variable *v, oid objid[], size_t *objid_len,
   /* Return number of routing entries. */
   result = 0;
   for (rn = route_top (table); rn; rn = route_next (rn))
-    for (rib = rn->info; rib; rib = rib->next)
+    RNODE_FOREACH_RIB (rn, rib)
       result++;
 
   return (u_char *)&result;
@@ -175,7 +175,7 @@ ipCidrNumber (struct variable *v, oid objid[], size_t *objid_len,
   /* Return number of routing entries. */
   result = 0;
   for (rn = route_top (table); rn; rn = route_next (rn))
-    for (rib = rn->info; rib; rib = rib->next)
+    RNODE_FOREACH_RIB (rn, rib)
       result++;
 
   return (u_char *)&result;
@@ -369,7 +369,7 @@ get_fwtable_route_node(struct variable *v, oid objid[], size_t *objid_len,
 	{
 	  if (!in_addr_cmp(&(*np)->p.u.prefix, (u_char *)&dest))
 	    {
-	      for (*rib = (*np)->info; *rib; *rib = (*rib)->next)
+	      RNODE_FOREACH_RIB (*np, *rib)
 	        {
 		  if (!in_addr_cmp((u_char *)&(*rib)->nexthop->gate.ipv4,
 				   (u_char *)&nexthop))
@@ -388,12 +388,12 @@ get_fwtable_route_node(struct variable *v, oid objid[], size_t *objid_len,
 
       /* Check destination first */
       if (in_addr_cmp(&np2->p.u.prefix, (u_char *)&dest) > 0)
-        for (rib2 = np2->info; rib2; rib2 = rib2->next)
+	RNODE_FOREACH_RIB (np2, rib2)
 	  check_replace(np2, rib2, np, rib);
 
       if (in_addr_cmp(&np2->p.u.prefix, (u_char *)&dest) == 0)
         { /* have to look at each rib individually */
-          for (rib2 = np2->info; rib2; rib2 = rib2->next)
+	  RNODE_FOREACH_RIB (np2, rib2)
 	    {
 	      int proto2, policy2;