zebra: northbound changes for the rib model

This commit implements:
RIB operational list create/destroy.
Walk over RIB tables using keys.
The first RIB table will be IPV4/unicast (table-id 254)
will be fetched.
Create a new api to fetch RIB table based on
afi-safi and table id as the keys.

remove mandatory true statement from the leaf which
is part of the list key.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang/frr-zebra.yang

@@ -642,7 +642,6 @@ module frr-zebra {
           type identityref {
             base afi-safi-type;
           }
-          mandatory true;
           description
             "AFI, SAFI name.";
         }

zebra/zebra_nb_config.c

@@ -29,6 +29,7 @@
 #include "zebra_nb.h"
 #include "zebra/interface.h"
 #include "zebra/connected.h"
+#include "zebra/zebra_router.h"
 
 /*
  * XPath: /frr-zebra:zebra/mcast-rpf-lookup
@@ -1220,12 +1221,40 @@ int lib_interface_zebra_bandwidth_destroy(struct nb_cb_destroy_args *args)
  */
 int lib_vrf_ribs_rib_create(struct nb_cb_create_args *args)
 {
+	struct vrf *vrf;
+	afi_t afi = AFI_IP;
+	safi_t safi = SAFI_UNICAST;
+	struct zebra_vrf *zvrf;
+	struct zebra_router_table *zrt;
+	uint32_t table_id;
+
+	vrf = nb_running_get_entry(args->dnode, NULL, false);
+	zvrf = vrf_info_lookup(vrf->vrf_id);
+	table_id = yang_dnode_get_uint32(args->dnode, "./table-id");
+	if (!table_id)
+		table_id = zvrf->table_id;
+
+	/* TODO: once identityref nb wrapper available, parse
+	 * afi-safi-name and feed into the creation of the table
+	 */
+
+	zrt = zebra_router_find_zrt(zvrf, table_id, afi, safi);
+
 	switch (args->event) {
 	case NB_EV_VALIDATE:
+		if (!zrt) {
+			zlog_debug("%s: vrf %s table is not found.", __func__,
+				   vrf->name);
+			return NB_ERR_VALIDATION;
+		}
+		break;
 	case NB_EV_PREPARE:
 	case NB_EV_ABORT:
+		break;
 	case NB_EV_APPLY:
-		/* TODO: implement me. */
+
+		nb_running_set_entry(args->dnode, zrt);
+
 		break;
 	}
 
@@ -1234,14 +1263,10 @@ int lib_vrf_ribs_rib_create(struct nb_cb_create_args *args)
 
 int lib_vrf_ribs_rib_destroy(struct nb_cb_destroy_args *args)
 {
-	switch (args->event) {
+	if (args->event != NB_EV_APPLY)
-	case NB_EV_VALIDATE:
+		return NB_OK;
-	case NB_EV_PREPARE:
+
-	case NB_EV_ABORT:
+	nb_running_unset_entry(args->dnode);
-	case NB_EV_APPLY:
-		/* TODO: implement me. */
-		break;
-	}
 
 	return NB_OK;
 }

zebra/zebra_nb_state.c

@@ -22,6 +22,7 @@
 #include "libfrr.h"
 #include "zebra_nb.h"
 #include "zebra/interface.h"
+#include "zebra/zebra_router.h"
 
 /*
  * XPath: /frr-interface:lib/interface/frr-zebra:zebra/state/up-count
@@ -149,20 +150,57 @@ lib_interface_zebra_state_mcast_group_get_elem(struct nb_cb_get_elem_args *args)
 
 const void *lib_vrf_ribs_rib_get_next(struct nb_cb_get_next_args *args)
 {
-	/* TODO: implement me. */
+	struct vrf *vrf = (struct vrf *)parent_list_entry;
-	return NULL;
+	struct zebra_router_table *zrt =
+		(struct zebra_router_table *)list_entry;
+
+	struct zebra_vrf *zvrf;
+	afi_t afi;
+	safi_t safi;
+
+	zvrf = zebra_vrf_lookup_by_id(vrf->vrf_id);
+
+	if (list_entry == NULL) {
+		afi = AFI_IP;
+		safi = SAFI_UNICAST;
+
+		zrt = zebra_router_find_zrt(zvrf, zvrf->table_id, afi, safi);
+		if (zrt == NULL)
+			return NULL;
+	} else {
+		zrt = RB_NEXT(zebra_router_table_head, zrt);
+		/* vrf_id/ns_id do not match, only walk for the given VRF */
+		while (zrt && zrt->ns_id != zvrf->zns->ns_id)
+			zrt = RB_NEXT(zebra_router_table_head, zrt);
+	}
+
+	return zrt;
 }
 
 int lib_vrf_ribs_rib_get_keys(struct nb_cb_get_keys_args *args)
 {
-	/* TODO: implement me. */
+	const struct zebra_router_table *zrt = list_entry;
+
+	keys->num = 2;
+
+	snprintf(keys->key[0], sizeof(keys->key[0]), "%s",
+		 "frr-zebra:ipv4-unicast");
+	/* TODO: implement key[0], afi-safi identityref */
+	snprintf(keys->key[1], sizeof(keys->key[1]), "%" PRIu32, zrt->tableid);
+
 	return NB_OK;
 }
 
 const void *lib_vrf_ribs_rib_lookup_entry(struct nb_cb_lookup_entry_args *args)
 {
-	/* TODO: implement me. */
+	struct vrf *vrf = (struct vrf *)parent_list_entry;
-	return NULL;
+	struct zebra_vrf *zvrf;
+	afi_t afi = AFI_IP;
+	safi_t safi = SAFI_UNICAST;
+
+	zvrf = zebra_vrf_lookup_by_id(vrf->vrf_id);
+
+	return zebra_router_find_zrt(zvrf, zvrf->table_id, afi, safi);
 }
 
 /*
@@ -170,21 +208,48 @@ const void *lib_vrf_ribs_rib_lookup_entry(struct nb_cb_lookup_entry_args *args)
  */
 const void *lib_vrf_ribs_rib_route_get_next(struct nb_cb_get_next_args *args)
 {
-	/* TODO: implement me. */
+	const struct zebra_router_table *zrt = parent_list_entry;
-	return NULL;
+	const struct route_node *rn = list_entry;
+
+	if (list_entry == NULL)
+		rn = route_top(zrt->table);
+	else
+		rn = srcdest_route_next((struct route_node *)rn);
+
+	return rn;
 }
 
 int lib_vrf_ribs_rib_route_get_keys(struct nb_cb_get_keys_args *args)
 {
-	/* TODO: implement me. */
+	const struct route_node *rn = list_entry;
+	char dst_buf[PREFIX_STRLEN];
+	const struct prefix *dst_p;
+
+	srcdest_rnode_prefixes(rn, &dst_p, NULL);
+	keys->num = 1;
+	strlcpy(keys->key[0], prefix2str(dst_p, dst_buf, sizeof(dst_p)),
+		sizeof(keys->key[0]));
+
 	return NB_OK;
 }
 
 const void *
 lib_vrf_ribs_rib_route_lookup_entry(struct nb_cb_lookup_entry_args *args)
 {
-	/* TODO: implement me. */
+	const struct zebra_router_table *zrt = parent_list_entry;
-	return NULL;
+	struct prefix p;
+	struct route_node *rn;
+
+	yang_str2prefix(keys->key[0], &p);
+
+	rn = route_node_lookup(zrt->table, &p);
+
+	if (!rn)
+		return NULL;
+
+	route_unlock_node(rn);
+
+	return rn;
 }
 
 /*
@@ -193,8 +258,9 @@ lib_vrf_ribs_rib_route_lookup_entry(struct nb_cb_lookup_entry_args *args)
 struct yang_data *
 lib_vrf_ribs_rib_route_prefix_get_elem(struct nb_cb_get_elem_args *args)
 {
-	/* TODO: implement me. */
+	const struct route_node *rn = list_entry;
-	return NULL;
+
+	return yang_data_new_prefix(xpath, &rn->p);
 }
 
 /*
@@ -203,8 +269,9 @@ lib_vrf_ribs_rib_route_prefix_get_elem(struct nb_cb_get_elem_args *args)
 const void *
 lib_vrf_ribs_rib_route_route_entry_get_next(struct nb_cb_get_next_args *args)
 {
-	/* TODO: implement me. */
+	struct route_entry *re = NULL;
-	return NULL;
+
+	return re;
 }
 
 int lib_vrf_ribs_rib_route_route_entry_get_keys(

zebra/zebra_router.c

@@ -66,6 +66,22 @@ zebra_router_table_entry_compare(const struct zebra_router_table *e1,
 	return (e1->safi - e2->safi);
 }
 
+struct zebra_router_table *zebra_router_find_zrt(struct zebra_vrf *zvrf,
+						 uint32_t tableid, afi_t afi,
+						 safi_t safi)
+{
+	struct zebra_router_table finder;
+	struct zebra_router_table *zrt;
+
+	memset(&finder, 0, sizeof(finder));
+	finder.afi = afi;
+	finder.safi = safi;
+	finder.tableid = tableid;
+	finder.ns_id = zvrf->zns->ns_id;
+	zrt = RB_FIND(zebra_router_table_head, &zrouter.tables, &finder);
+
+	return zrt;
+}
 
 struct route_table *zebra_router_find_table(struct zebra_vrf *zvrf,
 					    uint32_t tableid, afi_t afi,

zebra/zebra_router.h

@@ -186,6 +186,9 @@ extern void zebra_router_init(void);
 extern void zebra_router_cleanup(void);
 extern void zebra_router_terminate(void);
 
+extern struct zebra_router_table *zebra_router_find_zrt(struct zebra_vrf *zvrf,
+							uint32_t tableid,
+							afi_t afi, safi_t safi);
 extern struct route_table *zebra_router_find_table(struct zebra_vrf *zvrf,
 						   uint32_t tableid, afi_t afi,
 						   safi_t safi);