Merge pull request #2897 from donaldsharp/zebra_rnh_fixup

zebra: When registering a nexthop, we do not always need to re-eval

staticd/static_zebra.c

@@ -34,6 +34,7 @@
 #include "log.h"
 #include "nexthop.h"
 #include "nexthop_group.h"
+#include "hash.h"
 
 #include "static_vrf.h"
 #include "static_routes.h"
@@ -43,6 +44,7 @@
 
 /* Zebra structure to hold current status. */
 struct zclient *zclient;
+static struct hash *static_nht_hash;
 
 static struct interface *zebra_interface_if_lookup(struct stream *s)
 {
@@ -176,10 +178,16 @@ static void zebra_connected(struct zclient *zclient)
 	zclient_send_reg_requests(zclient, VRF_DEFAULT);
 }
 
+struct static_nht_data {
+	struct prefix *nh;
+	uint32_t refcount;
+	uint8_t nh_num;
+};
 
 static int static_zebra_nexthop_update(int command, struct zclient *zclient,
 				       zebra_size_t length, vrf_id_t vrf_id)
 {
+	struct static_nht_data *nhtd, lookup;
 	struct zapi_route nhr;
 	afi_t afi = AFI_IP;
 
@@ -191,6 +199,14 @@ static int static_zebra_nexthop_update(int command, struct zclient *zclient,
 	if (nhr.prefix.family == AF_INET6)
 		afi = AFI_IP6;
 
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.nh = &nhr.prefix;
+
+	nhtd = hash_lookup(static_nht_hash, &lookup);
+	if (nhtd)
+		nhtd->nh_num = nhr.nexthop_num;
+
+
 	static_nht_update(&nhr.prefix, nhr.nexthop_num, afi, vrf_id);
 	return 1;
 }
@@ -200,10 +216,50 @@ static void static_zebra_capabilities(struct zclient_capabilities *cap)
 	mpls_enabled = cap->mpls_enabled;
 }
 
+static unsigned int static_nht_hash_key(void *data)
+{
+	struct static_nht_data *nhtd = data;
+
+	return prefix_hash_key(nhtd->nh);
+}
+
+static int static_nht_hash_cmp(const void *d1, const void *d2)
+{
+	const struct static_nht_data *nhtd1 = d1;
+	const struct static_nht_data *nhtd2 = d2;
+
+	return prefix_same(nhtd1->nh, nhtd2->nh);
+}
+
+static void *static_nht_hash_alloc(void *data)
+{
+	struct static_nht_data *copy = data;
+	struct static_nht_data *new;
+
+	new = XMALLOC(MTYPE_TMP, sizeof(*new));
+
+	new->nh = prefix_new();
+	prefix_copy(new->nh, copy->nh);
+	new->refcount = 0;
+	new->nh_num = 0;
+
+	return new;
+}
+
+static void static_nht_hash_free(void *data)
+{
+	struct static_nht_data *nhtd = data;
+
+	prefix_free(nhtd->nh);
+	XFREE(MTYPE_TMP, nhtd);
+}
+
 void static_zebra_nht_register(struct static_route *si, bool reg)
 {
+	struct static_nht_data *nhtd, lookup;
 	uint32_t cmd;
 	struct prefix p;
+	afi_t afi = AFI_IP;
 
 	cmd = (reg) ?
 		ZEBRA_NEXTHOP_REGISTER : ZEBRA_NEXTHOP_UNREGISTER;
@@ -224,20 +280,48 @@ void static_zebra_nht_register(struct static_route *si, bool reg)
 		p.family = AF_INET;
 		p.prefixlen = IPV4_MAX_BITLEN;
 		p.u.prefix4 = si->addr.ipv4;
+		afi = AFI_IP;
 		break;
 	case STATIC_IPV6_GATEWAY:
 	case STATIC_IPV6_GATEWAY_IFNAME:
 		p.family = AF_INET6;
 		p.prefixlen = IPV6_MAX_BITLEN;
 		p.u.prefix6 = si->addr.ipv6;
+		afi = AFI_IP6;
 		break;
 	}
 
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.nh = &p;
+
+	si->nh_registered = reg;
+
+	if (reg) {
+		nhtd = hash_get(static_nht_hash, &lookup,
+				static_nht_hash_alloc);
+		nhtd->refcount++;
+
+		if (nhtd->refcount > 1) {
+			static_nht_update(nhtd->nh, nhtd->nh_num,
+					  afi, si->nh_vrf_id);
+			return;
+		}
+	} else {
+		nhtd = hash_lookup(static_nht_hash, &lookup);
+		if (!nhtd)
+			return;
+
+		nhtd->refcount--;
+		if (nhtd->refcount >= 1)
+			return;
+
+		hash_release(static_nht_hash, nhtd);
+		static_nht_hash_free(nhtd);
+	}
+
 	if (zclient_send_rnh(zclient, cmd, &p, false, si->nh_vrf_id) < 0)
 		zlog_warn("%s: Failure to send nexthop to zebra",
 			  __PRETTY_FUNCTION__);
-
-	si->nh_registered = reg;
 }
 
 extern void static_zebra_route_add(struct route_node *rn,
@@ -373,4 +457,8 @@ void static_zebra_init(void)
 	zclient->interface_address_delete = interface_address_delete;
 	zclient->route_notify_owner = route_notify_owner;
 	zclient->nexthop_update = static_zebra_nexthop_update;
+
+	static_nht_hash = hash_create(static_nht_hash_key,
+				      static_nht_hash_cmp,
+				      "Static Nexthop Tracking hash");
 }

zebra/zapi_msg.c

@@ -1022,6 +1022,7 @@ static void zread_rnh_register(ZAPI_HANDLER_ARGS)
 	unsigned short l = 0;
 	uint8_t flags = 0;
 	uint16_t type = cmd2type[hdr->command];
+	bool exist;
 
 	if (IS_ZEBRA_DEBUG_NHT)
 		zlog_debug(
@@ -1064,7 +1065,10 @@ static void zread_rnh_register(ZAPI_HANDLER_ARGS)
 				p.family);
 			return;
 		}
-		rnh = zebra_add_rnh(&p, zvrf_id(zvrf), type);
+		rnh = zebra_add_rnh(&p, zvrf_id(zvrf), type, &exist);
+		if (!rnh)
+			return;
+
 		if (type == RNH_NEXTHOP_TYPE) {
 			if (flags
 			    && !CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED))
@@ -1084,7 +1088,9 @@ static void zread_rnh_register(ZAPI_HANDLER_ARGS)
 
 		zebra_add_rnh_client(rnh, client, type, zvrf_id(zvrf));
 		/* Anything not AF_INET/INET6 has been filtered out above */
-		zebra_evaluate_rnh(zvrf_id(zvrf), p.family, 1, type, &p);
+		if (!exist)
+			zebra_evaluate_rnh(zvrf_id(zvrf), p.family, 1, type,
+					   &p);
 	}
 
 stream_failure:

zebra/zebra_rnh.c

@@ -103,7 +103,8 @@ char *rnh_str(struct rnh *rnh, char *buf, int size)
 	return buf;
 }
 
-struct rnh *zebra_add_rnh(struct prefix *p, vrf_id_t vrfid, rnh_type_t type)
+struct rnh *zebra_add_rnh(struct prefix *p, vrf_id_t vrfid, rnh_type_t type,
+			  bool *exists)
 {
 	struct route_table *table;
 	struct route_node *rn;
@@ -119,6 +120,7 @@ struct rnh *zebra_add_rnh(struct prefix *p, vrf_id_t vrfid, rnh_type_t type)
 		prefix2str(p, buf, sizeof(buf));
 		zlog_warn("%u: Add RNH %s type %d - table not found", vrfid,
 			  buf, type);
+		exists = false;
 		return NULL;
 	}
 
@@ -136,7 +138,9 @@ struct rnh *zebra_add_rnh(struct prefix *p, vrf_id_t vrfid, rnh_type_t type)
 		route_lock_node(rn);
 		rn->info = rnh;
 		rnh->node = rn;
-	}
+		*exists = false;
+	} else
+		*exists = true;
 
 	route_unlock_node(rn);
 	return (rn->info);
@@ -190,6 +194,14 @@ void zebra_delete_rnh(struct rnh *rnh, rnh_type_t type)
 	route_unlock_node(rn);
 }
 
+/*
+ * This code will send to the registering client
+ * the looked up rnh.
+ * For a rnh that was created, there is no data
+ * so it will send an empty nexthop group
+ * If rnh exists then we know it has been evaluated
+ * and as such it will have a resolved rnh.
+ */
 void zebra_add_rnh_client(struct rnh *rnh, struct zserv *client,
 			  rnh_type_t type, vrf_id_t vrf_id)
 {
@@ -201,8 +213,7 @@ void zebra_add_rnh_client(struct rnh *rnh, struct zserv *client,
 	}
 	if (!listnode_lookup(rnh->client_list, client)) {
 		listnode_add(rnh->client_list, client);
-		send_client(rnh, client, type,
-			    vrf_id); // Pending: check if its needed
+		send_client(rnh, client, type, vrf_id);
 	}
 }
 
@@ -247,9 +258,10 @@ void zebra_register_rnh_pseudowire(vrf_id_t vrf_id, struct zebra_pw *pw)
 {
 	struct prefix nh;
 	struct rnh *rnh;
+	bool exists;
 
 	addr2hostprefix(pw->af, &pw->nexthop, &nh);
-	rnh = zebra_add_rnh(&nh, vrf_id, RNH_NEXTHOP_TYPE);
+	rnh = zebra_add_rnh(&nh, vrf_id, RNH_NEXTHOP_TYPE, &exists);
 	if (rnh && !listnode_lookup(rnh->zebra_pseudowire_list, pw)) {
 		listnode_add(rnh->zebra_pseudowire_list, pw);
 		pw->rnh = rnh;

zebra/zebra_rnh.h

@@ -68,7 +68,7 @@ static inline int rnh_resolve_via_default(int family)
 }
 
 extern struct rnh *zebra_add_rnh(struct prefix *p, vrf_id_t vrfid,
-				 rnh_type_t type);
+				 rnh_type_t type, bool *exists);
 extern struct rnh *zebra_lookup_rnh(struct prefix *p, vrf_id_t vrfid,
 				    rnh_type_t type);
 extern void zebra_free_rnh(struct rnh *rnh);